Resources doi: 10.3390/resources15080107

Authors: Ana Flávia Vieira Pontes Lucas Tadeu Fuess Marcelo Zaiat

This study evaluated the anaerobic valorization of real, non-detoxified sugarcane bagasse-derived pentose liquor. Direct fermentation without nutrients, co-substrate, or buffering was limited, reaching low-to-moderate (37–54%) carbohydrate conversion efficiency at low organic loading rate (OLR < 5.6 kg COD m−3 d−1) levels. Hydrogen yield (HY) was also low (0.63–0.89 mol H2 mol−1 carbohydrateconverted) under these conditions. Increasing pentose liquor concentration up to 0.8 L L−1 and OLR of 30.2 kg COD m−3 d−1 suppressed hydrogen production, coinciding with lactate accumulation and the occurrence of homoacetogenesis. Enhanced fermentation with sucrose, nutrients, buffering, shorter hydraulic retention time (12 h) and 37 °C improved stability and carbohydrate conversion (50–61%) under higher OLR, although HY considerably decreased (0.14–0.35 mol H2 mol−1). Methanogenesis was effective in both single- and two-stage systems, with carbohydrate conversion usually above 95%, COD removal up to 83.5%, methane fractions above 60%, and methane yields reaching 299.8–301 NmL CH4 g−1 CODremoved. Furfural and 5-HMF showed phase-dependent transformation, indicating partial in situ detoxification during anaerobic conversion. Overall, pentose liquor is better valorized through integrated hydrogen–methane recovery than by fermentation alone. Future studies should focus on both applying more effective strategies to buffer the fermentative stage and adopting more conservative approaches (lower OLR) to start up the methanogenic systems.

Resources doi: 10.3390/resources15080106

Authors: Abu Shahadat Md Ibrahim Roderick G. Eggert

Proton exchange membrane (PEM) electrolyzers and fuel cells could substantially increase demand for iridium (Ir) and platinum (Pt), two platinum-group metals (PGMs) with concentrated primary supply chains. This study evaluates secondary Ir and Pt supply from end-of-life PEM technologies using a scenario-based material-flow analysis for global and U.S. markets from 2020 to 2050. Annual metal demand is estimated from U.S. Department of Energy annual PEM manufactured-capacity inputs, which include new and replacement systems, and from catalyst loading rates. Secondary supply is estimated using distributed lifetimes, collection efficiency, technical recovery efficiency, recycling delay, loss accounting, remaining primary requirement, and surplus. Under the central practical case, recovered Ir supplies 16.9% of global and 3.8% of U.S. PEM electrolyzer Ir demand in 2050. Recovered PEM electrolyzer Pt supplies 32.2% of global and 7.3% of U.S. demand, while recovered PEM fuel-cell Pt supplies 75.1% of global and 51.2% of U.S. demand. Sensitivity and uncertainty results show that recovery outcomes depend strongly on collection performance, recycling delay, technical recovery, catalyst loading, and capacity-input assumptions. PEM recycling can reduce future primary PGM requirements, especially for Pt, but cannot eliminate primary Ir demand during rapid PEM electrolyzer scale-up.

Resources doi: 10.3390/resources15080105

Authors: Márta Kreidlmayer Karl-Johan Fabó Máté Tóth Péter Balling Antal Kneip Laura Varga Péter Molnár Zoltán Szekér Réka Matolcsi Adrien Fenyvesi Mihály Konkoly Csaba Zsolt Oláh Barnabás Kovács István Kiss Tamás Köpeczi-Bócz Sándor Némethy

Vineyards and wineries generate seasonal, wet and compositionally variable side-streams whose safe use is constrained by rapid spoilage, contaminants, fragmented regulation and scale. This EU-focused structured narrative review synthesised 90 scientific and official sources and proposes an integrated decision framework rather than another catalogue of valorisation routes. The framework applies a non-compensatory sequence: characterise and stabilise the batch, test route-specific hazards, assign evidence-level and technology readiness, verify legal eligibility, define a safe fallback, and only then compare material flows, environmental burdens and risk-adjusted economics. Current implementation evidence is strongest for controlled composting, conventional wastewater treatment, anaerobic digestion and selected grape-seed oil, polyphenol and heat-integrated biochar operations; clinical, plant-protection and several novel-extract claims remain product- and context-specific. Illustrative ENPV cases show that high-value extraction can offer greater upside but lower robustness than compost/biochar when moisture, transport, rejection and price uncertainty are included. The framework provides an auditable basis for pilot design, regional cooperation and data collection, while explicitly requiring industrial and multi-season validation before investment or product approval.

Resources doi: 10.3390/resources15080104

Authors: Abu Shahadat Md Ibrahim Maxwell Fleming Elif Bozkurt Tom Brady Ian Lange

Recovery of critical materials from industrial byproducts is often presented as a near-term United States (U.S.) supply-security strategy, yet contained inventories, pilot output, announced capacity, and commercial production are not equivalent. This study evaluates eight U.S. pathways for gallium, germanium, tellurium, lithium, magnesium, and cobalt, classified as operational, demonstration/pilot, announced target-year, or technical upper-bound cases. Facility- and stream-specific quantities were converted to qualifying domestic output and incorporated into same-stage material balances under explicit assumptions for utilization, eligibility, demand, and import displacement. Supply risk was calculated from the net import dependence and governance-adjusted production and trade concentration using a geometric index, with arithmetic formulations as robustness checks. The operational U.S. copper-refining tellurium pathway yielded the largest central reduction (49.29%). Announced 2030 Clarksville capacity reduced modeled risk by 13.87% for gallium and 8.75% for germanium, conditional on project completion, feed attribution, product qualification, utilization, and demand. All other central cases produced reductions of 4.63% or less; the current lithium demonstration, Stillwater cobalt, and aluminum-residue magnesium cases had negligible national effects. Policy support should therefore be differentiated by qualifying output, market scale, project maturity, and evidence quality rather than by contained material or nameplate capacity alone.

Resources doi: 10.3390/resources15080103

Authors: Jheyson Andres Bedoya Londoño Giovanni Franco Sepúlveda Fredy Castrillón Galeano

Sustainable Mining Districts (SMDs) have recently emerged as a territorial governance approach for promoting sustainable mining; however, no integrated conceptual framework currently exists to support their strategic planning. This study develops the first multidimensional conceptual framework for SMDs by integrating evidence from the scientific literature, institutional analysis, and territorial characterization, using Colombia as an illustrative case. The results reveal a growing international research emphasis on sustainability, governance, and territorial planning in mining, together with an emerging institutional transition toward district-scale governance. These findings support the identification of eleven complementary planning dimensions—geological, mining, transformation, environmental, social, market, economic, financial, infrastructure, legal, and governance—that collectively characterize SMDs as integrated territorial systems rather than solely geological or administrative units. The proposed framework provides a structured conceptual basis for organizing multidisciplinary information and supporting strategic territorial planning through an illustrative set of key performance indicators (KPIs). Although conceived as a proof of concept requiring future empirical validation, the framework offers a foundation for evidence-informed planning and governance of mining territories in Colombia and other mineral-producing regions.

Resources doi: 10.3390/resources15080102

Authors: Karim Zongo Moussa dit Corneille Tarpilga Yssa Traoré Bétaboalé Naon Hervé Pierre Ravelonandro

This study explores the utilization of local biomass through slow pyrolysis in a multifunctional domestic reactor, with a view to producing renewable energy and improving soil quality in arid regions. Four underutilized biomass sources were studied: millet stalks, cashew shells, cashew shell meal, and rumen contents. Thermal monitoring using thermocouples showed pyrolysis temperatures ranging from 270 to 350 °C, while the combustion chamber reached up to 800 °C depending on the biomass. Four thermal phases were identified (heating, devolatilization, stabilization, and cooling), confirming stable reactor operation. Gas analyses revealed a predominance of CO (approximately 1000 ppm) as well as variations in O2, H2S, and hydrocarbons, indicating a conversion process dependent on the type of biomass and interactions between chambers. Mass and energy balances show that performance depends heavily on the physicochemical properties of the feedstocks, particularly the content of volatiles, lignin, and ash. Cashew shells exhibited the highest energy efficiency (approximately 42.9%), followed by rumen contents (approximately 34.4%), while cashew shell meal showed lower performance due to prior extraction of volatiles. Biochar yields and energy distribution vary significantly depending on the biomass, highlighting the importance of feedstock selection in decentralized pyrolysis systems. Overall, household pyrolysis enables simultaneous energy recovery and biochar production under realistic, non-optimized conditions. These results provide new insights into biomass–reactor interactions and support the development of decentralized bioenergy solutions tailored to sub-Saharan regions.

Resources doi: 10.3390/resources15080101

Authors: Antonija Ereš Josip Radić Dalibor Kramarić Marijana Hadzima-Nyarko Ivanka Netinger Grubeša

The construction sector relies heavily on virgin mineral resources and produces significant quantities of construction and demolition waste. This study examines crushed brick aggregate (CBA) as a volumetric substitute for natural river sand in micro-concrete at replacement levels of 0%, 25%, 50%, 75%, and 100%. Results show that increasing CBA content decreases consistency and flexural strength while increasing water absorption. However, compressive strength is maintained even at full replacement. One-way ANOVA demonstrated significant overall effects of CBA replacement level on all investigated properties. However, Tukey’s HSD comparisons indicated that not all adjacent replacement levels exhibited significant differences. Specifically, compressive strength at 25% and 50% replacement did not differ significantly from the reference mixture. A nominal resource-efficiency assessment based on the absolute-volume method and literature-derived density values indicates that, at 25% volumetric replacement, the mixture incorporates approximately 286.7 kg/m3 of CBA and saves 362.4 kg/m3 of natural sand while retaining 94.3% of the reference compressive strength. For Croatia’s estimated 8882 t of waste bricks in 2024, a maximum yield scenario suggests production of about 30,985 m3 of this mixture and natural sand savings of approximately 11,231 t. The 25% replacement level offers the most balanced outcome in terms of secondary resource utilisation, consistency, mechanical performance, and water absorption.

Resources doi: 10.3390/resources15080100

Authors: Mario Luna-del Risco Claudia Janeth Gómez-David Mauricio González-Palacio Lisandra Rocha-Meneses David Ulises Santos-Ballardo Eber Enrique Orozco Guillen Esteban Vanegas-Trujillo Alisson Dahian Patiño-Agudelo

The agricultural and livestock sectors of Latin America produce a large number of residues that could be converted into energy through bioenergy production processes. However, the bioenergy sector still faces several limitations across the region, including fragmented logistics systems, weak coordination among institutions, and limited integration of environmental, digital, and compliance-related performance indicators. This review systematically analyses residue-based bioenergy value chains in Latin America between 2015 and 2025 using the PRISMA methodology to evaluate selected peer-reviewed studies and regional reports indexed in Scopus, ScienceDirect, SpringerLink, and IEEE Xplore, and institutional repositories. The final synthesis included 37 studies and institutional contributions, which were further disaggregated into 208 country–residue observations for the regional and feedstock distribution analysis. The review identified three main research gap categories: the limited integration of collection and logistics systems, the insufficient treatment of uncertainty, circularity, and traceability within optimization models, and the weak incorporation of governance and institutional coordination into bioenergy value-chain design. The analysis includes biogas, biomethane and related residue-based systems, with attention to supply-chain optimization, policy alignment, methane mitigation metrics, and traceability requirements. Results indicate that although technologies such as biomass pretreatment, process intensification, and upgrading processes continue to improve conversion performance, most studies still focus mainly on technical feasibility and biomass potential. Less attention is given to governance constraints, uncertainty analysis, and monitoring systems capable of supporting regulatory compliance. This research introduced the Sustainable Bioenergy Chain Management Framework (SBCMF) to respond to these limitations and bring together different aspects of bioenergy management within one analytical structure. The framework combines supply-chain optimization under spatial and temporal constraints, circular economy valorisation, methane-related climate performance, and digital traceability, while also linking techno-economic system design with governance and monitoring requirements. In this way, it can help support the development of more transparent and low-carbon bioenergy systems across Latin America.

Resources doi: 10.3390/resources15080099

Authors: Chaimae El Yaacoubi Mohamed Bensaddik Nihade Bensitel Fatima-Zahra Azar Fouad Dimane Yahya El Hammoudani Achraf El Kasmi

Rapid population growth has led to increasing quantities of wastewater treatment sludge, creating environmental, economic, and public health challenges that require sustainable management strategies. This review critically examines recent advances in wastewater sludge management by evaluating sludge characterization, conventional and emerging valorization technologies, and the application of life cycle assessment (LCA) as a decision-support tool. The analysis shows that sludge can be successfully valorized through agricultural reuse, energy recovery, industrial applications, and resource recovery. However, the suitability of each pathway depends on sludge properties, environmental conditions, regulatory requirements, and economic feasibility. LCA highlights the environmental trade-offs associated with different management scenarios and provides a systematic framework for comparing their environmental and economic performance while supporting circular economy principles. Overall, integrating sludge valorization with comprehensive life cycle assessment enables more informed decision-making and promotes environmentally sustainable and economically viable wastewater sludge management. This review provides practical insights for researchers, policymakers, and industry stakeholders seeking to optimize sludge management strategies and advance sustainable wastewater treatment.

Resources doi: 10.3390/resources15080098

Authors: Sudatta Maity Priti Pal Akhilesh Singh Anand Prakash Krystyna Kondratowicz-Maciejewska Piotr Prus Prakash Sarangi

The world’s food industry faces significant obstacles today as it strives to meet the nutritional needs of its rapidly expanding global population while also managing an immense amount of food processing waste (FPW) generated throughout the entire food supply chain. The widespread use of traditional disposal techniques for food waste (landfilling and incineration) regularly faces challenges related to environmental sustainability and economic efficiency. This manuscript reviews the necessary transition from a linear “take-make-dispose” approach to food production to a more circular model that recycles food waste into high-value intermediate chemicals and renewable energy through the development of biorefineries. The manuscript explores the biochemical composition of food waste, with carbohydrates, lipids, proteins, and bioactive materials, making it a suitable feedstock for different multi-stage biorefinery operations. In addition, this review will evaluate a variety of existing conversion technologies for food processing waste, such as biological methods (e.g., anaerobic digestion and fermentation) and thermochemical methods (e.g., pyrolysis, gasification, and hydrothermal liquefaction), to create various platform chemicals, including organic acids, bio-alcohols and volatile fatty acids (VFAs), as well as the production of sustainable biofuels and biopolymers. The review also elucidates the three most determinative constraints on large-scale industrial implementation of food waste valorisation: feedstock variability, techno-economic feasibility, and the need for comprehensive life cycle assessments (LCAs). The alignment of food waste management strategies with the UN SDGs (in particular, SDG 12 ‘Responsible Consumption and Production’ and SDG 13 ‘Climate Action’) reflects the opportunity for food waste to serve as a foundation for a carbon-neutral, sustainable future. This review provides a strategic roadmap for academics, practitioners, and policymakers to tap into the full potential of food waste through a sustainable circular economy model.

Resources doi: 10.3390/resources15080097

Authors: Raikhan Beisenova Ainur Orkeyeva Anar Rakhmetova Zhanar Rakhymzhan Rumiya Tazitdinova

This study investigates hydroclimatic variability and water balance dynamics in the Akmola region during 2003–2023 using observations from 16 meteorological stations. The study evaluates changes in air temperature, precipitation, reference evapotranspiration (ET0), climatic water balance, and drought conditions. Reference evapotranspiration was calculated using the FAO-56 Penman–Monteith method, while drought variability was assessed using the 12-month Standardized Precipitation–Evapotranspiration Index (SPEI-12). Temporal trends were analyzed using the Mann–Kendall test and Sen’s slope estimator. The results revealed significant spatial heterogeneity in hydroclimatic conditions across the region. Air temperature showed a consistent increasing trend at most stations, accompanied by increasing atmospheric evaporative demand. All stations were characterized by a persistently negative climatic water balance, with mean annual values of approximately −750 mm, indicating a regional moisture deficit. Reference evapotranspiration exhibited significant spatial variability, with the highest values observed in the southern and central parts of the region. Precipitation remained the dominant control of water balance variability (r = 0.79–0.96), while increasing temperature intensified moisture deficits through increased evapotranspiration. SPEI-12 indicated recurrent drought episodes and increasing drought vulnerability associated with warming-induced atmospheric water demand. The study demonstrates that increasing evapotranspiration is becoming a major driver of water stress in the Akmola region and highlights the importance of integrating climatic water balance and SPEI indicators for drought monitoring and climate adaptation in semi-arid steppe regions.

Resources doi: 10.3390/resources15070096

Authors: Yasmine Boukhlouf Mohammed Benabdelhadi Hassan Tabyaoui Abderrahim Lahrach Abdallah Oulmekki Maryame El-Yazidi Zineb El Attar Soufi Omar Kassou

Construction and demolition waste is one of the most voluminous yet poorly managed waste streams in developing cities, and Fez, Morocco, is no exception. With over 1.2 million inhabitants and an expanding construction sector, the city produces large quantities of building debris annually. Until this study, no systematic inventory of illegal dumpsites existed, and municipal documents contained no data on volumes, composition, or spatial distribution. We addressed this gap through three approaches: a field survey of 43 illegal dumpsites, a permit-based Waste Generation Rate (WGR) analysis with projections to 2040, and a Simplified Material Flow Analysis (MFA) integrating field-observed stocks and theoretical generation estimates into a city-scale mass balance. The 43 surveyed sites hold a combined volume of 15,626,019 m3, with an average inert content of 51.60%, below the 65% benchmark, reflecting systematic co-deposition with no sorting. Only 11.6% of sites showed high recovery potential. The waste generation rate estimates a total generation of 419,269–1,426,302 tonnes over 2016–2025, with demolition accounting for 64% of the output. The materiel flow analysis reveals a 2- to 7-fold discrepancy between observed stock levels and theoretical estimates. Without intervention, generation is projected to increase sevenfold by 2040. Fez is caught in an informal disposal trap. Three actions are needed: mandatory traceability, targeted enforcement at high-flow sites, and on-site recycling capacity.

Resources doi: 10.3390/resources15070095

Authors: Edison Ramírez-Olivares Catalina Rojas-Rojas Gillyan Gálvez-Rodríguez Juan Alfaro Robles

The mining industry faces increasing challenges in enhancing productivity within complex operational environments characterized by the interaction of technical, organizational, human, and external factors. Nevertheless, existing studies frequently examine these determinants independently, thereby limiting a comprehensive understanding of their relative importance and combined influence on operational performance. This study develops a decision framework to identify and prioritize the factors affecting productivity in medium-scale mining in the Coquimbo Region, Chile, through the application of the Analytic Hierarchy Process (AHP) based on expert judgment obtained from active mining operations. The AHP model was structured using two criteria, seven subcriteria, and twenty-three decision factors, whose consistency and reliability were assessed through the consistency ratio (CR) and Cronbach’s alpha coefficient. The results revealed a marked predominance of Internal factors (75.0%) over External factors (25.0%), indicating that productivity is influenced primarily by variables that can be managed at the organizational level. Among the evaluated subcriteria, Work planning achieved the highest priority (32.0%), whereas Scheduling and control (10.2%), Human factors (6.4%), and Working conditions (5.2%) emerged as the most influential decision factors. Furthermore, sensitivity analysis confirmed the robustness and stability of the model. Beyond establishing a prioritization of productivity determinants, this study provides a decision-support framework that can assist mining companies in strengthening productivity management and improving operational performance in medium-scale mining.

Resources doi: 10.3390/resources15070094

Authors: Clifftone Wanyonyi Mbuku Rogerio Borguete Rafael John Walker Recha

The accumulation of agricultural waste poses significant agronomic and environmental challenges in tropical smallholder farming systems where organic wastes remain underutilized. This study evaluated the effectiveness of vermicomposting with Eisenia fetida in enhancing nutrient recovery and improving the quality of organic fertilizers produced from agricultural waste. Four substrate treatments—poultry manure and vegetable waste (T1), cow dung, chicken manure, and vegetable waste (T2), cow dung and vegetable waste (T3), and a control without earthworms (T4)—were assessed over a period of 60 days. Key physicochemical properties evaluated included bulk density, pH, electrical conductivity, organic carbon, total nitrogen, available phosphorus and potassium, and the C:N ratio. Vermicomposting significantly improved nutrient composition, with the C:N ratio decreasing from 26.43 in the control treatment to 12.23, indicating enhanced compost maturity. Treatment T2 recorded the highest concentrations of total nitrogen (2.63%), phosphorus (1.21%), and potassium (1.45%). A significant reduction in organic carbon also indicated enhanced mineralization during the decomposition process. Compared with traditional composting, vermicomposting improved nutrient availability, compost maturity, and overall compost quality. These findings demonstrate that vermicomposting is an effective resource recovery strategy for converting agricultural waste into nutrient-rich organic fertilizer while supporting sustainable and climate-resilient agricultural systems.

Resources doi: 10.3390/resources15070093

Authors: Abu Ibrahim Roderick Eggert

Platinum group metals (PGM) are essential for clean-energy technologies, including proton exchange membrane (PEM) electrolyzers for hydrogen production and PEM fuel cells for hydrogen use, as well as catalytic, electronic, and advanced industrial applications. However, their supply is exposed to geological concentration, co-product dependence, and market volatility. This study evaluates the medium-term cost-based accessibility of known primary PGM resources using a cumulative availability curve. The analysis combines resource estimates and allocated production-cost data for 61 known PGM-bearing deposits and projects, with costs expressed in 2022 USD per metric ton of combined PGM output. Because PGM deposits differ in ore type, processing route, and co-product setting, the results are interpreted by deposit cluster rather than only by country or aggregate cost threshold. The low-cost portion of the curve is dominated by Ni–Cu sulphide by-product systems, but this cluster represents only 1.87% of the compiled resource base. In contrast, UG2/Merensky/Great Dyke reef-type systems account for 72.95%, and Platreef/Northern Limb and Platreef-type systems account for 19.82%. Thus, most known primary PGM resources occur outside the low-cost by-product segment. Cluster-weighted PGM basket-price benchmarks are used instead of individual metal-price comparisons. Several cluster-level cost ranges fall below or near indicative April 2025 basket-price benchmarks, but these comparisons are not project-level profitability tests. Overall, the cumulative availability curve provides a deposit-cluster-based framework for evaluating known primary PGM availability and informing critical-material policy, recycling strategy, supply-chain planning, hydrogen-technology deployment, and responsible resource development.

Resources doi: 10.3390/resources15070092

Authors: Faozi A. Almaqtari Najib H. S. Farhan Abdulhadi Ibrahim Amal Yamani Khalid Hamad Alturki

This study examines the relationship between renewable energy consumption (REC) and carbon dioxide (CO2) emissions and investigates the moderating role of country-level governance in 39 Renewable Energy Country Attractiveness Index (RECAI) economies over the 1996–2020 period. Drawing on institutional and environmental governance theories, this study evaluates whether governance strengthens the environmental benefits of renewable-energy consumption. Unlike previous studies that primarily focus on aggregate governance measures, this study separately examines six governance dimensions: control of corruption, political stability, rule of law, government effectiveness, regulatory quality, and voice and accountability. Using panel data from the World Bank, the analysis employs fixed-effects estimation and validates the findings through robust regression, the generalized method of moments (GMM), and panel-corrected standard error (PCSE) approaches. The results indicate that renewable energy consumption significantly reduces both CO2 emissions per capita and total CO2 emissions in the long run. The findings further show that governance significantly moderates the renewable energy–CO2 emissions relationship, with stronger governance enhancing the emission-reducing effect of renewable energy consumption. Governance mitigates the environmental impacts associated with urbanization and industrialization, highlighting the importance of institutional quality in managing the structural drivers of emissions. The robustness analyses confirm the consistency of the main results across the alternative estimation techniques. This study contributes to the literature by providing evidence of the distinct roles of individual governance dimensions in shaping environmental outcomes in economies actively engaged in renewable energy development. These findings suggest that renewable energy expansion and governance reforms should be pursued simultaneously to achieve more effective carbon emission reduction strategies.

Resources doi: 10.3390/resources15070091

Authors: Triswan Suseno Zulfahmi Zulfahmi Harta Haryadi Edwin Daranin Yuhelda Dahlan Teuku Ishlah Eko Santoso Tatang Padmawidjaja Purnama Sendjaja Mustafa Hanafi Martua Parningotan Nendaryono Madiutomo

This research aims to analyze the resilience of Indonesia’s copper ore reserves in supporting sustainable copper cathode production targets, in line with national downstream policies. Using a quantitative approach, this study evaluates secondary data from national mineral reserve reports and the production capacity of major smelters. The analysis is conducted by calculating the reserve-to-production ratio to project mine life under three scenarios of increasing domestic refining capacity, including an aggressive scenario of 1.145 million tons per year. The results indicate that based on current reserves, the estimated mine life is approximately 21 years under maximum production capacity. However, with potential resource-to-reserve conversion of approximately 4.318 billion tons and accounting for ore grade decline, the life of Indonesia’s copper ore reserves is projected to extend until 2077. The study also reveals a structural gap, where 70% of cathode production is still export-oriented due to low domestic manufacturing absorption. The uniqueness of this paper lies in the integration of geological reserve aspects with the dynamics of downstream policies and industrial structure theories. Practically, this study provides important implications for the government in formulating strategic reserve management and emphasizes the urgency of integrating upstream smelting with downstream manufacturing to ensure long-term industrial sovereignty.

Resources doi: 10.3390/resources15070090

Authors: Igor A. G. Oliveira Neiton C. Silva Marcos A. S. Barrozo

Pitaya is a tropical fruit widely recognized for its intense coloration and abundance of bioactive compounds and natural pigments, associated with antioxidant properties and potential functional applications. However, its high moisture content and structural fragility make it highly susceptible to post-harvest deterioration and limit its shelf life, highlighting the need for effective preservation strategies to enable its industrial utilization. This study evaluated the production of spray-dried red pitaya (Hylocereus costaricensis) powder using the whole-fruit (pulp, peel, and seeds), since studies addressing entire fruit utilization remain scarce. The effects of air temperature (T), air flow rate (AF), maltodextrin concentration (M), and feed flow rate (FF) on moisture content, water activity, drying yield, bioactive compounds (total phenolic, flavonoid, ascorbic acid, and betalains), and color parameters were investigated. Spray drying successfully produced pitaya powders characterized by reduced moisture levels and water activity, satisfactory drying yield, and preserved bioactive compounds contents under selected processing conditions. The optimized spray drying conditions (T = 132.7 °C, AF = 1.51 m3/min; M = 9%, and FF = 0.55 L/h) were identified through the desirability function approach, indicating a balanced performance between drying efficiency and compound retention. Color parameters (L*, a*, b*, C*, H°, and ΔE) showed changes related to the operational conditions analyzed when compared with the fresh fruit. These findings support the valorization of the pitaya whole fruit and its use as a source of natural bioactive compounds for food applications.

Resources doi: 10.3390/resources15070089

Authors: Clifftone Mbuku Rogerio Rafael John Recha

A sustainable method of improving soil fertility and developing climate-resilient cropping systems is vermicomposting agricultural waste. This study hypothesized that vermicompost derived from mixed organic agricultural wastes would significantly improve soil fertility, crop productivity, and drought resilience compared to single-substrate treatments and the unamended control. The effects of vermicompost generated from mixed organic wastes using Eisenia fetida on soil quality, crop performance, and drought resilience of lettuce (Lactuca sativa, Eden variety) were evaluated in this study using a randomized complete block design. Crop performance indicators included germination, growth characteristics, biomass, SPAD chlorophyll content, and yield, while soil physicochemical properties, including pH, organic carbon, total nitrogen, available phosphorus, exchangeable potassium, electrical conductivity (EC), and cation exchange capacity (CEC), were assessed both before and after amendment application. The effects of drought stress were evaluated using leaf surface temperature, wilting score, recovery time, and survival rate. The results demonstrated that vermicompost application significantly improved soil fertility and crop performance relative to the control treatment (p < 0.05). The best-performing treatment (T2) increased soil organic carbon by approximately 22–28%, total nitrogen by 18–24%, available phosphorus by 20–27%, and exchangeable potassium by 16–21% compared with the control. Fresh biomass increased by approximately 14–17%, marketable yield improved by 16–24%, and SPAD chlorophyll values increased by nearly 20%, indicating enhanced photosynthetic efficiency and nutrient uptake. T2 showed the most resilience under drought stress, with ~94.9% survival rate, reduced wilting severity, shortened recovery time and sustained stable leaf temperature (~27.8 °C), whereas low-performing treatments and the control recorded survival rates of only ~70–78%. Mixed organic waste substrates consistently outperformed single-substrate treatments, demonstrating synergistic effects on nutrient cycling, microbial activity, soil structural quality, and drought tolerance. These findings provide quantitative evidence that vermicomposting can simultaneously enhance soil fertility, crop productivity, and drought resilience, highlighting its strong potential as a scalable climate-smart strategy for sustainable agriculture, circular bioeconomy development, and organic waste valorization in smallholder farming systems.

Resources doi: 10.3390/resources15070088

Authors: Adi Sutanto Iswahyudi Iswahyudi Ristika Handarini Marchel Garfansa Akh Fawaid Yenni Ekalaturrahmah Siti Amani Ika Dewi Zhulvie Meylanzharie Zakiyatuz Wahyudi Imam Wahyudi Muhammad Wahyudi

Madura cattle are a nationally important indigenous Indonesian beef cattle breed and a locally adapted genetic resource that supports smallholder livelihoods and beef production under tropical dryland, low-input farming conditions. As an indigenous Indonesian beef cattle breed raised predominantly by smallholder farmers in dryland and low-input systems, Madura cattle require integrated management practices that combine resource management, technical management, environmental management, and operational efficiency to improve farm performance. A quantitative survey was conducted with 400 farmers from Madura Island. Data were collected through structured interviews using a five-point Likert-scale questionnaire and analyzed using SEM-PLS by evaluating the measurement and structural models. The results show that all constructs met validity and reliability criteria. The model demonstrated adequate explanatory power, with adjusted R2 values of 0.369 for Operational Efficiency and 0.522 for Farm Performance. Resource Management, Technical Management, and Environmental Management had positive and significant effects on Operational Efficiency. Operational Efficiency also had a positive and significant effect on Farm Performance and partially mediated the relationships between the three management variables and Farm Performance. These findings indicate that improving Madura cattle farming performance requires stronger resource, technical, and environmental management supported by operational efficiency as a strategic mechanism to enhance production, reproduction, and economic performance sustainably.

Resources doi: 10.3390/resources15070087

Authors: Marianela Díaz-Llocclla Rebeca Salvador-Reyes Emerson Asto-Rodriguez Anahi Rodriguez Dominguez Maickol Andy Cano Otañe Gian Pierre Silvera-Otañe

Cocoa processing generates large amounts of agro-industrial by-products, mainly cocoa bean shells (CBS), cocoa pod husks (CPH), and cocoa mucilage, which remain underutilized despite their nutritional and bioactive potential. This narrative review critically analyzes the composition of cocoa by-products and emerging technologies for bioactive compound recovery. Results show that CBS and CPH are rich sources of dietary fiber (13.8–65.6%), phenolic compounds (up to 100 mg GAE/g), and methylxanthines (theobromine up to 11.6 mg/g in CBS). Emerging extraction technologies, ultrasound-assisted extraction, pressurized liquid extraction, microwave-assisted extraction, pulsed electric fields, and cold atmospheric plasma, improve extraction yield (20–150%), reduce processing time (from hours to minutes), and decrease solvent consumption compared to conventional methods. Regarding food applications, moderate CBS inclusion levels (10–20% in cookies, 2–8% in bread, 0.75–1.0% in sausages) improve dietary fiber and antioxidant capacity without compromising sensory acceptability, whereas higher levels (>20–30%) increase hardness, bitterness, and astringency. It is concluded that cocoa by-products are promising resources for sustainable functional food ingredients. However, industrial implementation remains limited by raw material variability, lack of standardized extraction protocols, sensory constraints, and insufficient biological validation of recovered compounds. Future research should focus on standardizing extraction protocols, validating bioaccessibility and bioactivity through in vivo studies, optimizing food formulations for sensory balance, assessing contaminants (heavy metals, mycotoxins), and evaluating techno-economic feasibility and life-cycle sustainability at industrial scale.

Resources doi: 10.3390/resources15070086

Authors: Nawal Louzi Mohammad Q. Al-Jamal Mahmoud AlJamal Ayoub Alsarhan Sami Aziz Alshammari

Sustainable pavement maintenance increasingly requires coordinated management of infrastructure condition, renewable-energy availability, carbon emissions, financial resources, and operational capacity. This study proposes a renewable-energy resource management framework for low-carbon network-level pavement maintenance using simulation-based pavement-energy modeling and multi-agent deep reinforcement learning. The proposed framework develops an AnyLogic-based pavement-energy simulation environment in which road sections, deterioration states, work zones, maintenance crews, equipment resources, photovoltaic generation, battery storage, grid support, diesel backup, carbon tracking, and budget consumption are represented within one integrated decision environment. To support adaptive maintenance control, pavement sections are modeled as interacting agents, while road connectivity, dispatch dependency, traffic interaction, and maintenance-route relationships are encoded through graph structures. A graph-based multi-agent deep reinforcement learning model, named Graph-MAPPO, is then used as the decision controller. The model integrates multi-head graph attention for spatial dependency learning, GRU-based temporal memory for deterioration-history representation, finite-element-assisted structural-risk indicators for hidden damage characterization, and constraint-aware action masking to prevent infeasible decisions under budget, carbon, energy, crew, and equipment constraints. Two calibrated datasets were generated to support the framework: a pavement network and maintenance dataset containing 4437 records and 55 features, and a renewable energy-carbon-budget dataset containing 9875 records and 38 features. The decision controller jointly selects the pavement section, treatment type, intervention timing, crew, equipment, and energy mode. Results from 20 experimental configurations show that the balanced Graph-MAPPO policy improves average PCI from 69.4 to 78.9, achieves an RSL gain of 6.8 years, reduces emissions to 58.3 tCO2e, maintains a renewable-energy share of 74.6%, and limits the constraint-violation rate to 1.8%. Under high renewable-energy availability, the framework achieves the best overall performance, with an average PCI of 80.2, renewable-energy share of 84.6%, emissions of 50.8 tCO2e, and reward of 0.90. These findings demonstrate that integrating pavement-energy simulation, renewable-energy resource allocation, carbon-aware maintenance planning, structural-risk awareness, and multi-agent decision control can support more adaptive, low-carbon, and resource-efficient pavement maintenance management.

Resources doi: 10.3390/resources15070085

Authors: Noura Ben Mbarek Ezer Ayadi

Growing concerns regarding resource efficiency, economic uncertainty, and energy-market volatility have renewed interest in the relationship between material-use patterns and macroeconomic stability. Recent global disruptions affecting production systems and economic activity have intensified policy attention toward sustainable resource management and resilience-oriented growth strategies. Using an unbalanced panel of 30 OECD economies over the period 1995–2024, this study examines the relationship between resource productivity and economic resilience while accounting for material-use intensity and structural conditions. The empirical framework relies on second-generation panel econometric techniques that account for cross-sectional dependence and heterogeneous country dynamics. The findings indicate that resource productivity is positively associated with economic resilience, with a 1% increase in resource productivity corresponding to an approximately 0.18% increase in resilience. By contrast, domestic material consumption and material footprint display negative associations with resilience, suggesting that resource-intensive production and consumption patterns may be linked to lower adaptive capacity and macroeconomic stability. The short-run estimates additionally indicate the persistence of adjustment dynamics following economic disturbances. These findings highlight the relevance of resource-use efficiency for macroeconomic resilience and sustainable resource-management strategies in OECD economies.

Resources doi: 10.3390/resources15070084

Authors: Srinithisathian Sathian Brema Jayanarayanan James Joseph Vijay Joseph Alexandre Gagnon

Wetlands are vital ecosystems that provide critical provisioning, regulating, cultural, and supporting services that underpin biodiversity conservation and local livelihoods. Despite their importance, ecosystem service valuation is often overlooked in coastal wetland restoration, limiting recognition of their contributions to the United Nations Sustainable Development Goals (SDGs). To address this gap and overcome methodological fragmentation in wetland assessments, this study develops the Integrated Ecosystem Valuation and Management of Wetlands (IEVMW) framework, which integrates the Millennium Ecosystem Assessment (MEA), Drivers–Pressures–State–Impact–Response (DPSIR) framework, IPCC climate risk assessment, and Total Economic Value (TEV) approaches into a unified methodology. The framework was applied to the Kol Wetlands in India to identify ecosystem services, assess climate-related risks, estimate economic values, and develop management recommendations. Results indicate that provisioning services contribute the highest economic value, followed by regulating and cultural services. Climate change was estimated to place approximately 11.7% and 13.0% of ecosystem service value at risk in North Kol and South Kol, respectively, corresponding to a combined economic value at risk of ₹42.9 crore, with provisioning services being the most vulnerable. The IEVMW framework provides a practical and scalable approach for linking ecosystem service valuation, climate risk assessment, and governance, thereby supporting climate-resilient wetland management and biodiversity conservation across diverse socio-environmental contexts.

Resources doi: 10.3390/resources15070083

Authors: Xuehan Song Jingling Li Yamin Jia Kaixuan Hao

The dumping of coal gangue poses significant risks to human health and ecosystems, necessitating ecological restoration in coal gangue mining areas. This study investigates the physical properties and water-retention characteristics of coal gangue–fly ash (CG-FA) substrates under varying coal gangue volume ratios and particle-size distributions, and evaluates their effects on alfalfa (Medicago sativa L.) growth. Six CG-FA volume ratios (5:5, 6:4, 7:3, 8:2, 9:1, 10:0) and seven particle-size distributions (1:1:1, 2:1:1, 3:1:1, 1:2:1, 1:3:1, 1:1:2, 1:1:3) were tested in 3 L pot experiments. Results showed that reducing coal gangue content significantly improved substrate structure, decreasing bulk density by 3.8–28.9% and increasing porosity by 9.8–64.4%, accompanied by enhanced water-retention capacity. The 5:5 volume ratio combined with a 1:2:1 particle-size distribution resulted in the highest alfalfa biomass, providing the best balance of substrate structure and water availability. From a resource-oriented perspective, the optimized CG–FA substrate enables the in situ utilization of coal-based solid wastes, reducing dependence on external soil resources while improving water retention and plant growth. These findings suggest potential advantages in resource utilization, economic feasibility, and environmental performance, providing a sustainable alternative for mine land restoration.

Resources doi: 10.3390/resources15060082

Authors: Hela Ben Hamida

Using a dataset covering January 1975 to March 2026 and six agricultural commodities, wheat, corn, soybeans, oats, sugar, and coffee, this paper explores the role of geopolitical risk (acts and threats) in shaping cross-market connectedness. It proposes a multilayer methodology based on the time-varying parameter vector autoregressive (TVP-VAR), the exponential GARCH with exogenous variables (EGARCH-X), and the wavelet quantile correlation (WQC) frameworks. This methodology captures cross-market volatility spillovers, assesses the effects of geopolitical risk and its components on the strength and instability of connectedness, and incorporates nonlinearity and asymmetry across investment horizons and market conditions. The results show a time-varying pattern in agricultural cross-market connectedness. Corn and soybeans transmit volatility shocks, while the other commodities are net receivers. These commodities have a central position in the connectivity network, whereas sugar and coffee are in the peripheral zone. The EGARCH-X results show that geopolitical acts and threats do not significantly alter the overall level of connectedness but intensify its volatility, suggesting that geopolitical tensions primarily influence stability rather than the intensity of connectedness. Economic policy uncertainty and oil price volatility have similar effects. In line with these results, the WQC analysis uncovers significant nonlinearity and state-dependent linkages, underscoring that the effect of geopolitical acts and threats becomes prominent over medium- and long-term horizons and during periods of market stress. These findings contribute to the literature by differentiating the effects of geopolitical incidents on agricultural market connectedness versus volatility. From an operational standpoint, these results imply that policymakers and market operators should enhance their risk-monitoring and hedging strategies during periods of high geopolitical stress, as such events can amplify instability across agricultural commodity markets.

Resources doi: 10.3390/resources15060081

Authors: Juan González-Menéndez Carlos Bustamante-Torres Bryan Salgado-Almeida Giannella Muriel-Granda Samantha Jiménez-Oyola Kenny Escobar-Segovia

Areas where mining activities overlap with agricultural production may promote the mobilization of potentially toxic elements (PTEs) into soils and water resources, thereby creating exposure pathways for populations living or working in these environments. This study analyzes the concentration of PTEs in agricultural soils and irrigation water from Santa Rosa, southern Ecuador, and assesses the associated health risks for exposed agricultural workers. For this purpose, 35 soil samples were collected from farms and 12 water samples from the irrigation canal during the dry season of 2025. The concentration of PTEs in soil and water was determined using X-ray fluorescence (XRF) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. The PTE concentration in both matrices was compared with the maximum permissible limits (MPL) established by Ecuadorian regulations. Non-carcinogenic hazard indices (HI) and carcinogenic risk (TCR) were estimated following the U.S. EPA methodology. In soil, As and Cr were the PTEs of greatest concern, exceeding the MPL in 93% of the samples and by up to 4.4 and 2.4 times, respectively, while in water, all PTEs were below the MPL. Non-carcinogenic risk was below the recommended limit for soil and water (HIsoil = 3.00 × 10−2 and HIwater = 2.00 × 10−3), with As as the dominant contributor. Cancer risk was tolerable in soil (TCRsoil = 4.34 × 10−5), while in water it remained at a low level (TCRwater = 1.65 × 10−6). These findings identify As and Cr as priority contaminants and support targeted monitoring and source-control measures in mining-influenced agricultural areas. Overall, by integrating agricultural soil and irrigation water quality with an occupational health risk assessment in Santa Rosa, this study contributes evidence to support future research in mining–agriculture coexistence areas.

Resources doi: 10.3390/resources15060080

Authors: María Belén Canchig Mateo Oleas Ariel Miranda Alfredo Viloria Ruth Oropeza Paola E. Ordóñez Marvin Ricaurte Alex Palma-Cando

Admiralty brass, commonly used in heat exchangers, is particularly susceptible to corrosion in acidic media such as those used in industrial cleaning. To mitigate this problem, the present study evaluated Musa acuminata (banana) peel and Lupinus mutabilis Sweet (Andean lupine) extracts as sustainable, low-toxicity corrosion inhibitors for admiralty brass in 0.5 M HCl. Six extracts were prepared using different solvents and characterized by qualitative and semi-quantitative phytochemical analyses (phenols, flavonoids, alkaloids). M. acuminata extracts were rich in phenolic compounds, while L. mutabilis extracts contained high levels of quinolizidine alkaloids. A comparative electrochemical screening of the agro-industrial waste-derived extracts revealed that the inhibition efficiency of M. acuminata extracts reached up to 43.6%, whereas the debittering wastewater extract of L. mutabilis (E6) achieved a maximum efficiency of 85.5% at 2000 ppm. A preliminary techno-economic analysis indicated the feasibility of industrial-scale production of the L. mutabilis-based inhibitor, yielding a net present value (NPV) of USD 9.48 million, an internal rate of return (IRR) of 27.3%, and a payback period of 6.7 years. These results demonstrate that agro-industrial residues can be valorized into effective and profitable green corrosion inhibitors, aligning with circular economy and sustainable chemistry principles.

Resources doi: 10.3390/resources15060079

Authors: Ezer Ayadi

Water scarcity is increasingly recognized as a macroeconomic challenge, yet its implications for sovereign financing conditions remain insufficiently understood. This study examines whether water scarcity is associated with sovereign borrowing costs and whether this relationship strengthens once hydrological pressure exceeds a critical threshold. Using an international panel of 105 countries over the period 2000–2024, the analysis combines second-generation panel diagnostics with nonlinear threshold estimation to examine long-run relationships and regime-dependent effects. The results indicate that water scarcity is positively associated with sovereign risk premiums, but the relationship is distinctly nonlinear. A critical threshold is identified at 61.37% water stress, beyond which the estimated association becomes substantially larger, with the coefficient increasing from 0.005 below the threshold to 0.024 above it. This pattern suggests that severe hydrological pressure is more strongly associated with higher sovereign borrowing costs than moderate water stress. The analysis further suggests that financial development, renewable energy deployment, and stronger institutional quality are associated with a weaker relationship between water scarcity and sovereign risk premiums, highlighting the potential importance of domestic resilience capacity. These findings remain broadly robust across alternative sovereign risk measures, alternative water scarcity proxies, dynamic specifications, and smooth-transition nonlinear models. This study contributes to the emerging literature on environmental macro-financial linkages by providing evidence that water scarcity may be increasingly relevant for sovereign financing conditions, particularly in economies facing severe and persistent hydrological stress.

Resources doi: 10.3390/resources15060078

Authors: Vasiliki Aravani Shiya Wang Wen Wang Vagelis Papadakis

The main sources of biodegradable waste come from agriculture and municipal waste, with animal manure and food waste (FW) being the most representative respectively. Most of this waste remains still unexploited, while there is skepticism regarding the environmental footprint of various methods of their utilization. This work provides a reliable comparative environmental evaluation using life cycle assessment (LCA). In the present work, LCA applied to compare two alternative scenarios regarding the management of (a) sheep and goat manure and (b) FW. Alternative scenarios for sheep and goat manure include composting for fertilizer and energy production via anaerobic digestion (AD), while FW scenarios include incineration and energy production through AD. In both case studies, the AD scenario generates environmental benefits (expressed as negative damage) across all three damage categories namely resource scarcity, human health and ecosystem quality. Regarding sheep and goat manure, the most significant effect of AD is on human health (−0.016 Pt) while in the scenarios of FW the superior performance of AD is particularly evident in the ecosystem quality (−0.21 Pt). Both case studies reached the same conclusion pointing out that the use of sustainable technologies for managing agricultural and municipal waste mitigates the environmental impacts.

Resources doi: 10.3390/resources15060077

Authors: Ihsen Abid

This study examines the dynamic relationships among oil prices, monetary conditions, and nominal GDP growth in Saudi Arabia, with particular attention to short-run adjustment and long-run equilibrium patterns in an oil-dependent economy operating under a fixed exchange-rate regime. Rather than identifying structural monetary policy shocks, the study focuses on reduced-form dynamic associations between market-based monetary indicators, oil-price movements, and nominal economic activity. Using a high-frequency monthly dataset covering key macroeconomic variables, the analysis employs the Autoregressive Distributed Lag (ARDL) framework to estimate both short-run dynamics and long-run equilibrium relationships. An Error Correction Model (ECM) is used to capture the speed of adjustment toward equilibrium, while Granger causality tests assess short-term predictive linkages. The empirical results reveal that monetary indicators, particularly interest rates and money supply, exhibit lagged and non-monotonic associations with nominal GDP growth, reflecting delayed transmission under exchange-rate constraints. Oil-price movements emerge as a dominant driver, showing strong contemporaneous and lagged associations with growth, whereas inflation and exchange-rate movements display limited short-run predictive relevance. The ECM results indicate relatively rapid convergence toward long-run equilibrium, suggesting efficient adjustment dynamics. Granger causality findings further confirm the short-term predictive content of key macroeconomic variables. By integrating high-frequency data with ARDL–ECM estimation, VAR-based robustness checks, and sensitivity analysis, the study provides evidence on how oil-price movements, liquidity conditions, and interest-rate dynamics jointly shape growth fluctuations in Saudi Arabia.

Resources doi: 10.3390/resources15060076

Authors: Nesrine Gafsi Ines Belgacem

The transition toward low-carbon economic systems has increased the strategic importance of green finance while simultaneously intensifying dependence on critical raw materials (CRMs) required for renewable energy technologies, energy storage systems, and electrification infrastructure. Despite the growing relevance of these interconnections, existing research has generally examined green finance, energy transition dynamics, and critical raw material sustainability separately, providing limited evidence on their combined interactions. This study develops an integrated finance–energy–resource framework to investigate the relationships among green finance, energy transition, and CRM sustainability. Using an unbalanced panel dataset covering 32 advanced and emerging economies over the period 2010–2022, the analysis employs the System Generalized Method of Moments (System GMM) estimator to address endogeneity, persistence effects, and unobserved heterogeneity. The empirical framework incorporates indicators of green finance, energy transition, CRM sustainability, and CRM supply risk, together with macroeconomic and institutional control variables. The results indicate that green finance contributes positively to CRM sustainability by supporting sustainable investment, resource efficiency, and environmentally responsible development. At the same time, the expansion of energy transition systems increases demand pressure on critical raw materials and may intensify supply-chain vulnerabilities. The findings further suggest the existence of feedback effects between resource constraints and financial systems through investment risk and capital allocation mechanisms. These results highlight the need for integrated policy approaches that align sustainable finance, energy transition objectives, and critical raw material governance to support long-term sustainability transitions.

Resources doi: 10.3390/resources15060075

Authors: Jhoseline Guillén Sánchez Henry Javier-Ninahuaman Rebeca Salvador-Reyes Gary Rojas-Hurtado Grimaldo Quispe Brenda Yauri Anhell Quispe-Calla

In accordance with the PRISMA 2020 guidelines, a systematic review was conducted on the green extraction of bioactive compounds from fruit matrices through the integration of emerging technologies and natural deep eutectic solvents (NADES). Studies published between 2015 and 2025 were analyzed from databases such as Scopus and Web of Science, and 63 relevant studies were selected following a rigorous methodological evaluation process. The results demonstrate a growing scientific interest in the use of NADES due to their sustainable nature, low toxicity, and high extraction efficiency, particularly when combined with technologies such as ultrasound and microwaves. These synergies enhance yield, reduce energy consumption, and preserve the stability of polyphenols, flavonoids, and anthocyanins. Furthermore, the physicochemical properties of NADES, such as polarity and viscosity, together with operational factors, such as temperature and water content, significantly influence process efficiency, indicating that the combination of NADES with emerging technologies represents a promising alternative for agri-food valorization with potential application as functional ingredients and in clean-label systems. Moreover, it is established as a robust strategy for the development of sustainable extraction processes with industrial scale-up prospects.

Resources doi: 10.3390/resources15060074

Authors: Javier Saldaña Almazán Sirilo Suastegui Cruz Marco Calderón Arellanes Enrique Moreno Mendoza Ana Leyva Zuñiga

Land degradation and declining groundwater availability threaten the sustainability of rural livelihoods across semi-arid regions. This study evaluates the hydrological performance of contour-based trenches as a low-cost and replicable nature-based solution (Nbs) for soil restoration, runoff regulation, and potential distributed managed aquifer recharge (MAR) in Guerrero, Mexico. The structures were installed on 12% slopes and designed using a simplified water balance criterion based on trench storage capacity, runoff coefficient, and representative rainfall events. Each trench was constructed along contour lines with overflow notches and connecting micro-trenches to improve hydraulic continuity, reduce erosion, and enhance infiltration opportunities under degraded field conditions. After one year of field monitoring, the trenches reached an average filling efficiency of approximately 90% per effective rainfall event, with estimated infiltration rates ranging from 0.0069 to 0.011 L·s−1. Soil moisture in the upper soil layer showed a relative increase of approximately 10–18% compared to adjacent untreated areas, while visible reductions in runoff velocity, sediment transport, and surface erosion were observed across the treated plot. Based on trench storage capacity, observed infiltration behavior, and assumed deep percolation fractions, the potential induced recharge was estimated between 216 and 360 m3·yr−1 (43–72 mm·yr−1). These values represent indicative plot-scale estimates rather than direct measurements of aquifer recharge, since no tracer studies or piezometric validation were performed. The results demonstrate that contour-based trenches contribute not only to infiltration enhancement and runoff control, but also to short-term soil restoration and improved water availability in rainfed agricultural systems. Their low-cost implementation, combined with community-based maintenance and adaptation to local environmental conditions, makes them a viable complementary strategy for strengthening decentralized water management, soil resilience, and climate adaptation in semi-arid rural landscapes. However, long-term effectiveness remains dependent on maintenance continuity, institutional support, and local governance conditions. Further multi-year monitoring and direct hydrogeological validation are recommended to improve the design and replicability of decentralized MAR systems.

Resources doi: 10.3390/resources15060073

Authors: Melike Yildirim Ayyildiz Jasemin Ölmez Christoph Hilgers

The European Union aims to reduce its dependency on imported critical and strategic raw materials. Therefore, the EU’s Critical Raw Materials Act defines benchmarks for strategic raw materials on domestic mining, recycling, refining, and the diversification of import sources to be achieved by 2030. This study investigates the feasibility of the EU’s Critical Raw Materials Act mining benchmark for strategic rare earth elements, which aims for 10% of the EU’s annual demand to be met through domestic mining. We assess whether domestic rare earth element supply from mining within the EU can meet the projected future demand for 2030 and 2050. The study also examines the extent to which the total demand of rare earth elements for the EU could be met proportionally. An uncertainty estimation with Monte Carlo simulation with consideration of uniform and Gaussian distribution, based on individual project development stages, highlights that reaching the 10% benchmark for strategic rare earth elements is theoretically likely by 2030; however, with an incorporated nine-year lead time, meeting the 2030 benchmark is no longer feasible. Furthermore, obstacles such as social license to operate, mining permits and appeals in practice may additionally prolong procedures. The study concludes that in order to mine domestic rare earth elements and to reduce import dependency, the EU needs to invest in geological exploration and mining. Moreover, establishing a whole rare earth elements supply chain from mining to refining is highly complex and, as illustrated by the Japan–Australia partnership, which required 14 years without including the geological exploration phase.

Resources doi: 10.3390/resources15060072

Authors: Fernando Pacheco Torgal

The construction sector must simultaneously meet rising global demand and cut embodied carbon deeply enough to satisfy European Green Deal and Bioeconomy Strategy targets—two pressures that conventional petrochemical-derived materials are poorly placed to resolve. Bio-based alternatives offer a credible path: they sequester carbon, carry lower embodied emissions, improve indoor air quality, and fit naturally within circular economy models. Yet they remain marginal in specification practice. This paper reviews the evidence on bio-based construction materials and maps the barriers that keep them there. The analysis organises these barriers into four levels—structural, economic, technical, and enabling—and traces the conditional relationships between them, with direct consequences for how policy interventions should be sequenced. The strategic case for this transition extends beyond environmental policy: the 2026 Strait of Hormuz disruption is used here as a scenario to show how dependent European construction is on fossil-derived material inputs, and how exposed that dependence leaves the sector to geopolitical supply shocks. The principal obstacles to adoption prove to be institutional and economic rather than technical—regulatory fragmentation, absent harmonised standards, fragile supply chains, and market structures that systematically undervalue bio-based solutions. The paper concludes that meaningful scaling requires coordinated action across governance, market design, and industrial policy, and that material and performance advances alone will not deliver it.

Resources doi: 10.3390/resources15060071

Authors: Ihsen Abid

This study investigates the macroeconomic, institutional, and energy-related determinants of agricultural value added in Middle East and North Africa (MENA) countries over the period 2000–2023, with particular emphasis on whether international clean energy finance operates as a conditionally effective driver depending on energy endowments. Using a panel fixed-effects framework with Driscoll–Kraay standard errors to address cross-sectional dependence, heteroskedasticity, and serial correlation, the analysis incorporates an interaction term between clean energy finance and an oil-exporting dummy to capture structural heterogeneity. Robustness is ensured through Panel-Corrected Standard Errors (PCSEs), Granger causality tests, and System GMM estimation. The findings reveal that GDP per capita and clean energy finance are positively and significantly associated with agricultural value added, while trade openness negatively affects the sector. Importantly, the interaction results indicate strong asymmetry: the positive contribution of clean energy finance is concentrated in non-oil economies but becomes weak or insignificant in oil-exporting countries, consistent with diminishing marginal returns in energy-abundant contexts. Inflation captures nominal price effects, while short-run dynamics suggest the presence of adjustment costs. Overall, the study highlights that clean energy finance acts as a structurally conditional mechanism, offering nuanced and policy-relevant insights for sustainable agricultural transformation in MENA economies.

Resources doi: 10.3390/resources15050070

Authors: Cesar Yahir Canales Barrientos Fredy Alberto Aliaga Yupanqui Yoisdel Castillo Alvarez Reinier Jiménez Borges Luis Angel Iturralde Carrera Berlan Rodríguez Pérez José Manuel Álvarez-Alvarado Juvenal Rodríguez-Reséndiz

Decarbonizing the building sector requires integrating on-site renewable generation with systematic energy management. Among the most widely adopted alternatives are photovoltaic (PV) systems in buildings; however, they are often implemented as a standalone technological intervention (size–install–estimate savings), without being formally incorporated into an Energy Management System (EnMS) aimed at continuous improvement. In this context, this research addresses this gap through an integrated methodological framework aligned with ISO 50001, in which PV is explicitly included in energy performance management through energy review, the definition of an Energy Baseline (EnB), and the monitoring of Energy Performance Indicators (EnPIs) within the PDCA cycle. The approach articulates the analytical sizing of the PV system based on electricity demand and solar resources; its validation through simulation to ensure operational consistency and a technical, economic, and environmental assessment that translates PV generation into a verifiable reduction in energy imported from the grid and, consequently, into traceable improvements in EnPI under an audit-compatible scheme. The methodology is demonstrated in a multi-family building in Chorrillos, Lima (Peru), where a 14.5 kWp rooftop PV system (25 modules of 580 Wp) is designed to maximize self-consumption during daylight hours. The results show technical performance consistent with the demand profile, economic viability under the conditions of the case, and environmental benefits from replacing grid electricity, along with offsets associated mainly with the manufacture of PV components. The residual gap between the Post-PV EnPIs and the ISO 50001 target confirms that PV integration is a necessary but not sufficient first-cycle action within a comprehensive building decarbonization strategy, with demand-side management and envelope improvements identified as subsequent PDCA cycle priorities. In summary, the central contribution is not the PV sizing itself, but its operational and traceable integration within ISO 50001, making PV a quantifiable, verifiable, and scalable energy improvement action for residential buildings in emerging economies.

Resources doi: 10.3390/resources15050069

Authors: Noura Ben Mbarek

Environmental implications of resource dependence remain a central concern for hydrocarbon-based economies undergoing energy transition. Using panel data for GCC countries over 1990–2024 and second-generation econometric techniques that account for cross-sectional dependence and heterogeneity, this study identifies a stable long-run relationship between natural resource rents, renewable energy, and CO2 emissions. The results show that a 1% increase in natural resource rents is linked to a 0.21% rise in CO2 emissions, highlighting the persistence of carbon-intensive economic structures. By contrast, renewable energy is associated with a 0.15% reduction in emissions, although its environmental contribution remains modest. The interaction effect is negative (−0.048) but only partially robust, indicating that renewable energy weakens, but does not fully offset, the environmental pressure associated with resource dependence. These findings suggest that energy transition in GCC economies remains gradual and structurally constrained, requiring not only renewable expansion but also deeper transformation of hydrocarbon-based growth models.

Resources doi: 10.3390/resources15050068

Authors: Abu Ibrahim Shivani Mathur Roderick Eggert

The rapid growth of battery energy storage and electric vehicles has increased lithium demand and intensified the attention given to the environmental performance of alternative extraction pathways. Conventional life cycle assessments (LCA) of lithium production typically report midpoint indicators in physical units, which limits cross-category comparison and reduces their usefulness for economic and policy analysis. This study presents a comparative monetized LCA of lithium carbonate equivalent (LCE) production from three pathways: solar brine evaporation, hard-rock spodumene mining, and geothermal brine recovery. Using the TRACI 2.1 midpoint results reported in a prior LCA, six impact categories—global warming, smog formation, acidification, respiratory effects, carcinogenic toxicity, and non-carcinogenic toxicity—are converted into monetary values through a benefit-transfer, damage-cost approach. Total environmental external costs are estimated at USD 11.85/kg LCE for solar brine evaporation, USD 9.45/kg LCE for spodumene mining, and USD 4.11/kg LCE for geothermal brine recovery (all USD amounts are expressed in $2025 unless otherwise mentioned). Smog formation contributes more than 80% of the total monetized damages across all pathways, while toxicity-related impacts account for a smaller share than implied by the normalized midpoint results. Monetization changes the relative ranking of the solar brine and spodumene pathways, while indicating that geothermal brine recovery has the lowest monetized external cost among the impact categories evaluated. These findings show that monetized LCA can complement conventional midpoint assessment and provide more decision-relevant insights for policy and economic evaluation.

Resources doi: 10.3390/resources15050067

Authors: Wagner Alves Carvalho Alessandro Lamarca Urzedo Natalí Romero Luciana Regaldo Leticia Ferreira Lima Machado Ana Maria Gagneten

Sustainable fertilization strategies are required to reduce dependence on synthetic inputs, enhance waste recycling, and improve agricultural resilience under climate change. This study evaluates the effects of wastewater-derived sludge, particularly when modified with Fe-montmorillonite, on phosphorus availability and early development of Zea mays. Methods: Germination and early growth of Zea mays were assessed under four treatments: (i) untreated soil (Control); (ii) soil amended with sludge from the Cardeal Wastewater Treatment Plant (SC); (iii) soil amended with Fe-montmorillonite-modified sludge (TechPhos, ST); and (iv) soil amended with a commercial phosphorus salt (PS). Soil characterization was conducted using XRF, XRD, and FTIR. Plant responses were evaluated through laboratory (5 days) and pot (22 days) experiments. Results: ST showed the highest performance, with a germination index of 171.7 and improved biomass, leaf development, and chlorophyll content compared to Control and SC. ST also performed similarly to or better than the commercial fertilizer (PS), indicating high phosphorus efficiency. Conclusions: The integration of nanostructured modified montmorillonite with wastewater-derived sludge represents a promising alternative phosphorus source for early maize development. Its application supports waste valorization and circular economy approaches while contributing to improved soil fertility and more sustainable nutrient management under climate change scenarios.

Resources doi: 10.3390/resources15050066

Authors: Nilofar Asim Marzieh Badiei Khadijehbeigom Ghoreishi

Although geopolymer and alkali-activated binders are promoted as low-carbon OPC alternatives, their resource-centric performance remains complex and geographically dependent. This review examines these systems from a resource-efficiency perspective and evaluates alkaline activator demand; precursor availability, including fly ash, slag, calcined clays, and mining residues; and embodied energy across mix designs and curing regimes. Recent mechanical and durability analyses, together with life cycle assessments, reveal important trade-offs in alkali-activated geopolymer systems. Customized precursors may unintentionally compromise their inherent resource efficiency, while the declining availability of industrial waste increasingly competes with alternative waste valorization processes. Developing one-part activator systems and implementing data- or machine-optimized mix designs capable of handling extremely highly variable waste streams will be necessary to achieve meaningful reductions in mineral consumption, energy demand, and emissions. The study reframes these binders as enablers of urban mining and industrial symbiosis. Policy changes toward resource-oriented governance, including performance-based standards, carbon-responsive procurement, and more transparent end-of-waste legislation, are also needed to promote a circular material economy. Strategic, large-scale deployment requires the integration of regional resource mapping with predictive performance modeling to navigate resource constraints in the construction sector.

Resources doi: 10.3390/resources15050065

Authors: Ihsen Abid

Purpose: This study examines the asymmetric effects of economic growth, energy consumption, renewable energy, trade openness, and innovation on CO2 emissions in China and India. It aims to determine whether positive and negative shocks in these variables generate different environmental responses across economies undergoing energy transition. Design/methodology/approach: The analysis employs a Nonlinear Autoregressive Distributed Lag (NARDL) model using annual data from 1990 to 2023. The framework decomposes explanatory variables into positive and negative partial sums to estimate asymmetric long-run and short-run effects. Dynamic multipliers are used to trace adjustment paths, while a symmetric ARDL model serves as a robustness check. Findings: The results reveal strong and persistent asymmetries in China, particularly in energy use, renewable energy, and innovation. Positive energy shocks significantly increase emissions, while reductions produce limited environmental gains, reflecting structural rigidities. Renewable energy reduces emissions asymmetrically, and innovation exhibits direction-dependent effects. In contrast, India shows weaker and more selective asymmetries, with emissions primarily driven by short-run energy demand and limited long-run structural effects. The symmetric model fails to capture these dynamics, confirming the importance of nonlinear modeling. Conclusion: The findings demonstrate that emissions dynamics are nonlinear and country-specific. Asymmetry is more pronounced in structurally advanced economies undergoing energy transition, while developing economies remain demand-driven. These results highlight the need for differentiated and context-specific environmental policies.

Resources doi: 10.3390/resources15050064

Authors: Alloysius Joko Purwanto Ridwan Dewayanto Rusli Citra Endah Nur Setyawati Tanawat Papaeng Nadiya Pranindita Ryan Wiratama Bhaskara Samantha Wibawa

This study examines the economics of blue and green hydrogen as feedstock for large industrial facilities in Southeast Asia. To understand how industries can adopt low-emission and renewable hydrogen, the levelised costs of blue and green hydrogen are calculated. Four pathways are examined, including a large-scale carbon capture and sequestration facility located a distance away from an existing steam methane reforming hydrogen plant, a gigawatt-scale electrolysis facility adjacent to a large industrial site fed by an adjacent solar photovoltaic electricity source, as well as two pathways with either remote electrolyser and solar photovoltaic, necessitating hydrogen transport and storage, or a remote solar photovoltaic source with a dedicated power transmission line. The region’s transition to green hydrogen must overcome the challenges of high renewable electricity costs, the need for large land banks for solar photovoltaic farms and efficient long-distance hydrogen transport solutions or power transmission lines. Moreover, the region must improve its inconsistent track record in implementing billion-dollar public–private projects within budget and on time.

Resources doi: 10.3390/resources15050063

Authors: Julia Chmiel Krystian Wolski Karolina Bakalorz Emmanuel Manirafasha Nikodem Kuźnik

Natural resources play a fundamental role in ensuring global food security, while agricultural production itself strongly influences their demand, extraction, and availability. This article discusses natural strategies for increasing crop productivity within the framework of sustainable intensification, focusing on the integrated role of plant biostimulants and micronutrients. Both groups of substances are analyzed from a resource-oriented perspective, highlighting their potential to be derived from renewable sources, particularly agro-industrial by-products and plant biomass. Plant extracts obtained from fruit, vegetable, and cereal processing residues contain numerous bioactive compounds, including phenolics, amino acids, peptides, and organic acids, which can stimulate plant growth, improve nutrient uptake, and enhance tolerance to abiotic stress. Micronutrients such as Fe, Zn, Mn, Cu, and B are also strategic resources in crop production because they regulate key metabolic processes and influence the efficiency of macronutrient utilization. Their effectiveness, however, depends strongly on chemical form and bioavailability in soil–plant systems. The novelty of this work lies in integrating perspectives from plant physiology, coordination chemistry, and resource management to propose a conceptual framework in which plant-derived extracts and micronutrient complexes act as complementary tools supporting circular and resource-efficient agricultural systems.

Resources doi: 10.3390/resources15050062

Authors: Marcin Pigłowski Maria Śmiechowska

Despite relatively low per capita rice consumption in the European Union (EU), averaging approximately 9 kg annually between 2010 and 2023, imports from Asian countries have shown a sustained upward trend since 2013. This study assessed hazards associated with rice available on the EU market. Data were obtained from Faostat, Eurostat, the Rapid Alert System for Food and Feed (RASFF), and the Web of Science. Pivot tables and a two-way joining cluster analysis were applied to examine temporal and geographical patterns in reported notifications. Notifications primarily concerned genetically modified rice (32%), pesticide residues (21%), and mycotoxins (17%). During 2006–2014, notifications mainly related to unauthorized genetic modifications in rice originating from China and the United States, whereas between 2017 and 2023, they predominantly involved excessive pesticide residues and mycotoxin contamination in rice from India and Pakistan. Most hazards were classified as border rejections (37%), reflecting the effectiveness and vigilance of EU food safety authorities. While rice is generally considered low risk for European consumers, rising cultural integration and the growing popularity of Asian cuisine may increase consumption in the future. Continuous monitoring, rigorous risk assessment, and collaboration with exporting countries are therefore essential to maintain high food safety standards and ensure consumer protection across the EU market.

Resources doi: 10.3390/resources15050061

Authors: Linda Karlina Sari Muchamad Bachtiar Noer Azam Achsani Reni Lestari

This study examines the dynamic interlinkages among energy, food, and metal commodity markets under geopolitical tensions using daily data from January 2022 to July 2025. The empirical framework integrates correlation analysis, Granger causality tests, and a Vector Error Correction Model (VECM) to capture both short- and long-run transmission mechanisms, with robustness assessed through impulse response functions, forecast error variance decomposition, and a Diebold–Yilmaz connectedness analysis across three structurally distinct geopolitical event windows. The results reveal asymmetric and sector-specific transmission patterns in which geopolitical risk significantly influences key commodity prices—particularly WTI crude oil, wheat, copper, and aluminium—confirming its role as a primary external shock driver. WTI emerges as the dominant transmitter of shocks, while industrial metals exhibit strong internal connectedness. Critically, gold’s role proves to be conditional and context-dependent: within an integrated energy–food–metal network under geopolitical stress, it functions primarily as a net receiver and passive absorber of macroeconomic uncertainty rather than as a systemic transmitter, a finding that complements, rather than contradicts, its established safe-haven role in financial asset pricing frameworks. These findings are subject to limitations, including reliance on futures price data and a linear VECM framework that may not fully capture nonlinear or regime-dependent dynamics.

Resources doi: 10.3390/resources15050060

Authors: Zhonggeng Luo Handong Liang Cai Tie Xiulong Gao

Coal resource exploitation may alter hydrogeological conditions and influence the occurrence and migration of coal-derived organic contaminants in mining regions. Among these contaminants, naphthenic acids (NAs) have received increasing attention, whereas their occurrence and environmental behavior in coal mining areas remain insufficiently understood. For the first time in an open-pit coal mining setting, this study systematically investigated the concentrations and molecular compositions of NAs in surface water, groundwater, and source-related water samples from the Shenfu Coalfield, a representative mining area in China. NAs were detected in all samples, with concentrations exhibiting clear spatial variability. Groundwater consistently contained substantially higher NA levels than surface water, and elevated concentrations in downstream river reaches coincided spatially with groundwater discharge zones, identifying groundwater as a key reservoir and transport pathway for NAs in the mining-affected watershed. Principal component analysis further revealed compositional similarities among groundwater, coal-washing wastewater, and certain surface-water samples, indicating contributions from both coal-bearing strata and coal-processing activities. These findings highlight the necessity of incorporating NAs into routine mine-water monitoring and groundwater protection programs in open-pit coal mining regions.

Resources doi: 10.3390/resources15040059

Authors: Nader Naifar

This paper investigates whether water-related climate stress predicts tail movements in food system assets and whether these spillovers vary across market regimes and investment horizons. Using daily data from January 2012 to January 2026, we examine the relationships among a water-risk proxy, agricultural commodities, agribusiness, and food supply-chain equities, and a fertilizer-related proxy. The analysis combines the cross-quantilogram with quantile spillover analysis in the frequency domain, allowing us to capture directional dependence in the tails of the distribution and short- and long-run connectedness. To account for structural change, we employ data-driven break detection and identify three major regimes: a pre-disruption period, a COVID-related adjustment phase, and a broader food system stress regime from early 2022 onward. The findings indicate that water-related climate stress has its strongest predictive power in the tails, especially for agribusiness and fertilizer-related assets, while the broad agricultural commodity basket is comparatively less sensitive. Lower-tail dependence is predominantly negative and often significant, whereas upper-tail dependence is generally positive, indicating asymmetric transmission under extreme market conditions. The spillover results further show that connectedness in the water–food system is mainly short-run, with agribusiness and fertilizer channels acting as the primary conduits of transmission. From a practical perspective, these findings suggest that investors and risk managers can use water-related market signals as early warning indicators of stress in food system assets, while policymakers can strengthen food system resilience through integrated water management, input market monitoring, and supply chain adaptation measures. The findings suggest that water-related climate stress is not merely an environmental constraint but a systemic source of food system risk with implications for resilience, risk monitoring, and integrated water-agriculture governance.

Resources doi: 10.3390/resources15040058

Authors: Bożena Gajdzik Radosław Wolniak Dominik Bałaga Wiesław Grebski

This study develops econometric models to examine greenhouse gas emissions associated with coal and natural gas consumption in Poland between 2015 and 2023. Poland has one of the most carbon-intensive energy systems in Europe. Three complementary log–log econometric models were estimated: a model explaining total CO2 emissions, a model assessing emission intensity (CO2 per unit of GDP), and a model capturing short-term variations in emission intensity. The results demonstrate that coal consumption remains the dominant determinant of absolute emissions, whereas the expansion of renewable energy significantly contributes to lowering the carbon intensity of economic growth. However, short-term fluctuations in emission intensity are still largely influenced by changes in fossil fuel consumption patterns. The findings highlight the gradual and sequential character of Poland’s energy transition, where gains in environmental efficiency precede a consistent reduction in total emissions. The proposed modeling framework offers an empirical basis for evaluating the effectiveness of climate and energy policies and can support the formulation of decarbonization strategies in economies heavily reliant on fossil fuels.

Resources doi: 10.3390/resources15040057

Authors: Liudmila I. Boguslavskaya Olga Batova Elena Katysheva Yulia Lyubek

This paper proposes an adaptive decarbonization model for the Russian non-ferrous metallurgy sector. The model accounts for the specific structure of the national energy balance (with nuclear and hydropower accounting for up to 40%), existing technological constraints, and regulatory risks, including the EU Carbon Border Adjustment Mechanism (CBAM). Based on a comparative analysis of key companies (RUSAL, Norilsk Nickel, and UMMC), an algorithm for the sequential assessment of decarbonization priorities is developed. Its core element is an integrated urgency indicator, which enables the ranking of enterprises according to their sensitivity to carbon-related restrictions. The model aims to minimize potential financial losses arising from external carbon taxation while leveraging the structural competitive advantages of the Russian energy system. The priority in decarbonization in Russia is determined not by the absolute level of technological development or the current carbon intensity of production, but by the degree of exposure to external regulatory and market risks combined with the ability to adapt. It is proven that in the current geopolitical and economic realities, the successful decarbonization of Russian non-ferrous metallurgy is impossible either as exclusively technological modernization or as a passive reaction to external regulatory pressure. The findings indicate that directly adopting international decarbonization strategies developed for the EU and North America (such as the EU Green Deal and CBAM) is ineffective due to fundamental differences in raw material bases, climatic conditions, and logistics.

Resources doi: 10.3390/resources15040056

Authors: Ornprapa Thepsilvisut Nuengruethai Srikan Preuk Chutimanukul Jutamas Romkaew

Asparagus (Asparagus officinalis L.) represents a high-value horticultural crop in Thailand with significant export potential; however, optimizing productivity in tropical environments requires a precise understanding of how cultivation practices and harvest seasons influence marketability. Here, a split-plot experiment arranged in a completely randomized design with three replications was conducted to examine how different crop methods and harvest seasons affect asparagus yield and quality in Lopburi Province, Thailand. The main plots were categorized by harvest season—summer, rainy, and winter—while the subplots included three crop methods: conventional, GAP, and organic. Summer produced the highest yield and asparagus with the greatest levels of total chlorophyll, phenolics, and DPPH radical scavenging activity compared to other seasons. Although the conventional methods yielded the most spears per plant, these spears contained higher levels of contaminants, including cadmium, lead, and nitrate. In contrast, spears from GAP and organic methods had higher phosphorus levels. However, no pesticide residues were found in any spear samples. Economically, the organic method had the shortest payback period, owing to lower production costs; despite a lower annual yield, stable market prices kept it profitable. In addition, organic soils had the highest levels of organic matter, nitrogen, and phosphorus. Overall, while conventional methods enhance the yield and certain qualities, organic farming, particularly when harvested in summer, yields the highest economic returns and the most sustainable system among those tested.

Resources doi: 10.3390/resources15040055

Authors: Andrzej Chmiela Beata Barszczowska Stefan Czerwiński Olena Trokhymets Małgorzata Magdziarczyk Adam Smoliński

Reducing and managing emissions of mine waters and the minerals dissolved in them, and above all, using these wastes as resources, is an important element of sustainable development in regions undergoing a gradual phase-out of fossil fuel extraction. This article examines selected aspects of mine water management and the mineral substances contained therein, using the Polish hard coal mining industry as a case study, providing valuable insights for both Poland and other mining regions reducing raw material extraction regarding the sustainability of social water demand, mining sector restructuring, and Sustainable Development Goals (SDGs). In Poland, underground hard coal mining remains a significant source of mine water and mineral salt emissions. Mine waters, discharged into the catchments of major rivers (approximately 200 million m3 per year) along with their dissolved mineral compounds (approximately 1.5 million Mg per year), have repeatedly contributed to serious environmental disruptions, e.g., the phenomena of so-called “fish kill”. This study analyzes both the scale of emissions and the economic utilization of mineralized mine waters discharged to the surface by underground hard coal mining in Poland. Key processes and potential causes for the observed increase in environmental burdens are discussed. Furthermore, the paper presents a current statistical assessment of the trends and scale of emission changes, which can serve as a basis for environmental management decision-making amidst the decarbonization of the economy. Utilizing potential water resources and mineral compounds from mine waters for internal use or within circular economy applications can reduce environmental pressure, support compliance with sustainable development policies, and mitigate long-term impacts on post-mining regions.

Resources doi: 10.3390/resources15040054

Authors: Thunyanat Hutangkoon Chumpol Yuangyai Tongchai Puttongsiri Viachaslau Filimonau Jarotwan Koiwanit

The global urgency to mitigate environmental degradation and promote sustainable resource use necessitates effective waste management strategies, particularly in the retail sector, which is a significant contributor to food waste. This study explores the carbon ramifications of food waste disposal methods within a hypermarket’s fresh food department in Bangkok, Thailand. Using the method of life cycle assessment (LCA) under the CML2001 framework, this study evaluates three food waste management methods: anaerobic digestion (AD), sanitary landfill, and mechanical and biological waste treatment (MBT). The analysis is structured to quantify the carbon footprint associated with each waste management strategy, measured in kilograms (kg) of carbon dioxide (CO2) equivalent (eq.) per kg of food waste. The estimated carbon footprint is 0.0066 kg CO2 eq./kg of food waste for MBT, 0.1221 kg CO2 eq./kg of food waste for AD, and 1.4667 kg CO2 eq./kg of food waste for sanitary landfill. These values were derived from defined system boundaries, modeling assumptions, and available operational data used to construct the life cycle inventory (LCI). In addition, a formal sensitivity analysis was not conducted in this study. Therefore, the reported values should be interpreted within the context of the modeling assumptions and data sources applied.

Resources doi: 10.3390/resources15040053

Authors: Nader Naifar

Commodity and carbon markets are central to natural resource allocation, energy security, and the effectiveness of carbon-pricing policies, yet their risk linkages can intensify sharply during crises. This study examines nonlinear, tail-dependent volatility spillovers across strategically important resource markets using a Quantile-on-Quantile connectedness framework. We employ weekly observed data from 3 January 2010 to 27 April 2025 for eleven futures markets spanning metals (copper, silver, gold), energy (WTI crude oil, heating oil, natural gas, gasoline), agricultural commodities (sugar, coffee, corn), and carbon emissions. Volatility is measured using GARCH-based estimates and embedded in quantile VAR dynamics to map state-contingent shock transmission across the distribution. The results indicate strong asymmetries: connectedness rises markedly in tail regimes and attains its highest levels during the COVID-19 pandemic and the Russia–Ukraine war, relative to the 2015–2016 energy market adjustment. Heating oil, gold, and natural gas frequently act as key volatility transmitters, while the carbon market shifts from a peripheral receiver to a more integrated and sometimes systemic node within the broader commodity risk network. The findings indicate that carbon-price risk propagates through resource markets in a regime-dependent manner, with implications for stress testing, tail-sensitive hedging, and the coordination of resource and climate policy under turbulent market states.

Resources doi: 10.3390/resources15040052

Authors: Praxedes Jeanpierre Merino-Ramirez Rebeca Salvador-Reyes

This systematic review examines the use of plant-derived extracts as antibacterial and antifungal agents in medical textiles, with an emphasis on active components, extraction techniques, biological efficacy, target microorganisms, and fabric application methods. This study is framed within the context of natural resource-based plant biomass and agro-industrial residues as a sustainable source of high-value functional compounds for resource valorization. Searches in Scopus and Web of Science followed the PIOC framework and PRISMA protocol. From an initial 389 records, 38 studies met the eligibility criteria. We identified a sustained growth in publications between 2020 and 2025, and six predominant thematic lines related to medical textiles, sustainability, antimicrobial assessment, structural characterization, natural dyeing optimization, and antioxidant functionalization. Among the most studied species, Aloe barbadensis and Salvia officinalis were prominent. Leaves were the most frequently used plant organ, highlighting their relevance as readily available renewable biomass resources. Maceration was the most common extraction method, although ultrasound-assisted extraction yielded a broader metabolite profile and better preserved thermolabile compounds, demonstrating the impact of biomass conversion techniques on resource efficiency and extract quality. Cotton 100% (plain weave) was the most widely used substrate, and the exhaustion method (immersion/exhaust dyeing) was the preferred application technique. Overall, plant extracts obtained through the sustainable management and valorization of plant resources achieved high inhibition against pathogenic bacteria, including resistant strains, and consistent antifungal activity, supporting their potential for developing functional and sustainable medical textiles. These findings align with the goals for responsible production and good health and well-being and reinforce the role of biomass-based resource systems within a circular bioeconomy, opening avenues to optimize formulations, standardize methodologies, and evaluate post-laundering performance and in vivo biocompatibility.

Resources doi: 10.3390/resources15040051

Authors: Cintia Monreal Jiménez Jonathan Rojas Ricca Robert Jäckel Joseph Adhemar Araoz Ramos Guillermo Barrios Alberto Ramos Blanco Geydy Gutiérrez-Urueta

The variability of solar energy limits its reliability as a thermal resource, motivating the use of thermal energy storage (TES) to extend heat availability beyond periods of direct irradiance. This study numerically compares latent and sensible TES integrated into a solar dish system from a resource-oriented perspective across representative Mexican climates. Rather than focusing only on stored energy, the analysis evaluates how each storage strategy affects the temporal availability and post-irradiation persistence of usable thermal energy over 24 h charge–discharge cycles. A salt-based PCM (58.1LiNO3–41.9KCl) was assessed against steel-based sensible storage under identical operating conditions. Under average-day forcing, the minimum PCM mass required to effectively utilize latent heat while sustaining a 320 W test load was found to be 13 kg. Under these conditions, the PCM case showed smoother thermal transients and longer post-irradiation energy availability, enabling nocturnal operation. In contrast, a mass-matched 13 kg steel store showed negligible post-irradiation availability, while a volume-matched 55 kg steel configuration achieved similar nocturnal operation only by substantially increasing mass, with limited improvement in accumulated energy. Hot-day forcing extended the operating window, whereas cold-day forcing yielded negligible charging so that operation could not be sustained within a single daily cycle.

Resources doi: 10.3390/resources15040050

Authors: Ubaldo Richard Marin Castro Marisol Castillo-Morales Guadalupe Luna-Solano Enrique Flores-Andrade Marco Antonio Salgado-Cervantes Manuel Vargas-Ortiz Adrien Servent

Tamarillo (Solanum betaceum) processing is characterized by early biomass exclusion and thermal stabilization, which may limit in-process retention of phytochemicals. This study evaluated an integrated sequence combining Flash Vacuum Expansion (FVE) under different processing conditions with whey protein-based cryostructuring as a strategy to enhance the redistribution and structural immobilization of tamarillo bioactives. FVE promoted migration of phenolics and pigments prior to mechanical fractionation. Selected FVE-treated puree was incorporated into a whey protein matrix and subjected to cryostructuring and freeze-drying to generate a porous stabilization scaffold. Structural characterization by scanning electron microscopy and gas adsorption confirmed the formation of an interconnected porous matrix. Cryostructuring reduced water activity to 0.17 ± 0.01 and produced high porosity (91.9%) with low bulk density (0.109 g·cm−3). Total phenolic retention exceeded 83%, while anthocyanins showed greater sensitivity (46% retention). No statistically significant additional losses of phenolics or antioxidant activity were observed during cryostructuring relative to gelation. The integrated approach illustrates a process-level stabilization pathway in which redistributed phytochemicals are physically confined within a porous scaffold, providing a structurally differentiated alternative to conventional drying for improved in-stream resource utilization.

Resources doi: 10.3390/resources15040049

Authors: Daniela Freitas Henrique Ribeiro Miguel Cabral Jorge Gominho

A characterization study of two by-products from the cork stopper industry was conducted to assess their suitability as components of growing media (substrate). Granulate of natural cork stopper (GNCS) and granulate of technical cork stopper (GTCS) were studied, evaluating their chemical composition, fractionation, effects on physical and chemical properties, mineral elements, and phytotoxicity. The two by-products were granulometrically classified into four categories: very fine fractions (≤1 mm), fine fractions (>1 and ≤2 mm), intermediate fractions (>2 and ≤5 mm), and coarse fractions (>5 and ≤10 mm). The highest proportion of granulates was observed within the intermediate fraction (>2 and ≤5 mm). GTCS presented significant limitations regarding the assessed properties, while the very fine fractions (≤1 mm) were the most attractive in both granulates. Therefore, selecting raw materials and their fractionation are vital for predicting the performance of growing media and establishing their suitability for promoting plant growth and productivity. Thus, these two by-products of the cork stopper industry have desirable characteristics as components of growing media.

Resources doi: 10.3390/resources15030048

Authors: Andres Canul-Manzanero Jorge Carlos Trejo-Torres Edgar Olguin-Maciel

Global energy demand relies heavily on fossil fuels, which produce greenhouse gas emissions. Additionally, municipal solid waste, driven by population growth, represents another source of emissions. In Mexico, organic waste contributes 61 million tons of CO2eq annually due to inadequate disposal. In Mérida, Yucatan, over 231,000 tons of organic waste are generated yearly, including Urban Tree Pruning (UTP) from 760 public spaces—a significant, undervalued lignocellulosic resource. This study presents a comprehensive, year-round compositional characterization of Mérida’s UTP to establish its chemical profile and assess its seasonal stability as a precursor for bio-based products (i.e., bioethanol). Characterizing local and stable feedstocks, such as UTP, is a fundamental step to enabling Mexico’s compliance with biofuel policies like the 5.8% gasoline blend mandate (NOM-016-CRE) and the Alcohol-to-Jet strategy, supporting progress toward SDGs 7, 11, and 13. Based on a stratified random sampling, monthly analysis (May 2024–April 2025) revealed a consistent biochemical profile with mean annual contents of 23.32% lignin and 62.46% holocellulose. Statistical analysis (Tukey’s test) confirmed its structural homogeneity throughout the year. This uniformity is a key operational attribute, as it allows for the use of standardized industrial pretreatment parameters. Furthermore, the characterized composition supports a theoretical ethanol yield of 170 g/kg of dry biomass, a value competitive with traditional feedstocks like sugarcane bagasse. Consequently, Mérida’s UTP is characterized as a reliable and consistent biomass resource, supporting a transition from linear waste disposal to a circular bioeconomy model.

Resources doi: 10.3390/resources15030047

Authors: Dang Thi Hong Ngoc Ngo Thi Hieu Tran Van Ty Nigel K. Downes Nguyen Thi Hong Diep Huynh Vuong Thu Minh

Drought is an increasing threat to livelihood security and sustainable development in the Vietnamese Mekong Delta (VMD), particularly in Kien Giang Province. This study examines the spatiotemporal dynamics of meteorological drought from 1992 to 2024 using daily rainfall data from 10 rain gauges. The Standardized Precipitation Index (SPI) was calculated at 3-, 6-, and 12-month timescales to assess short-, medium-, and longer-term precipitation deficits across the province. The results show that the most severe drought events were concentrated in the most recent decade, especially during the 2015–2016 and 2019–2020 dry seasons. Spatial analysis identified clear drought hotspots: the northern coastal zone, including Ha Tien and Hon Dat, exhibited the strongest long-timescale drought signal, while central inland areas such as Go Quao experienced more frequent short-timescale drought conditions. A significant negative relationship was also observed between SPI and the Oceanic Niño Index (ONI), indicating that El Niño conditions intensified drought severity, particularly in coastal areas. These findings highlight the need for spatially differentiated drought adaptation in Kien Giang Province, with stronger emphasis on water storage and water-use efficiency in inland districts and on early warning and integrated drought–salinity management in high-risk coastal zones.

Resources doi: 10.3390/resources15030046

Authors: B. Lokeshwari P. Saranraj Hawraa F. H. Al-Abedi Semaa F. H. Al-Abedi Haider H. E. Al-Magsoosi Mohammed T. Jaafar Israa M. Essa Hasanain A. J. Gharban K. Gayathri Alexander Machado Cardoso

The rapid expansion of the poultry industry has led to the large-scale generation of feather waste, creating serious environmental and public health concerns due to the recalcitrant nature of keratin. Poultry feathers are composed mainly of highly cross-linked keratin proteins stabilized by numerous disulfide bonds, which confer resistance to conventional proteolytic enzymes and natural degradation processes. This review examines the potential of keratinolytic fungi and their enzymes as sustainable, eco-friendly, and value-added strategies for poultry feather waste management and resource recovery. It discusses the environmental and health risks associated with improper feather disposal, such as pathogen proliferation, odor generation, and ecosystem contamination. Conventional management approaches, steam pressure hydrolysis, mechanical grinding, thermal treatment, acid–alkali hydrolysis, and oxidation, are critically evaluated in terms of efficiency and environmental impact. The review further highlights biological degradation pathways mediated by keratinolytic fungi and enzymes, with emphasis on fungal genera such as Aspergillus and Chrysosporium. Key mechanisms of fungal keratin degradation, including sulfitolysis, proteolysis, deamination, hyphal penetration, enzyme secretion, and biofilm formation, are discussed. Finally, industrial, agricultural, and feed applications of keratinases, along with advances in strain improvement, omics technologies, synthetic biology, and associated biosafety and regulatory considerations, are addressed.

Resources doi: 10.3390/resources15030045

Authors: Cláudio da Silva Junior Anantcha de Holanda Cavalcanti Clécio Lima Italo Durval Attilio Converti Andréa Costa Leonie Sarubbo

Agro-industrial waste-derived materials are promising candidates for short-cycle packaging applications. Here, we report a proof-of-concept for biodegradable biocomposites formulated with cassava residue (CR), sugarcane bagasse (SCB), and bacterial cellulose (BC) produced by symbiotic fermentation (SCOBY). This approach addresses the mechanical limitations typically associated with cassava starch-based matrices by introducing natural reinforcements to improve structural integrity and cohesion. A set of formulations with varying CR/BC/SCB ratios was processed and assessed through tensile and flexural testing, elongation at break, thermal analysis, and water-related behavior (sorption, absorption, and contact angle). Among the evaluated blends, formulation F1 (80% CR, 5% BC, 15% SCB) delivered the best overall balance between performance and moldability, achieving a tensile strength of 11.97 MPa and showing good dimensional stability. Biodegradability was confirmed by composting, reaching 72.74% mass loss after 84 days. Overall, BC incorporation improved matrix cohesion and enabled control of mechanical integrity and wettability in the blends, as highlighted for F1 (tensile strength 11.97 MPa; peak force 560.32 N; contact angle 65°; water absorption rate, WAR, 58.68%; sorption time 5.4 s). Given the abundance of sugarcane and cassava residues in Northeast Brazil, this low-complexity route leverages locally available feedstocks to add value to regional waste streams and support the partial replacement of synthetic polymers.

Resources doi: 10.3390/resources15030044

Authors: Amina Hamdouni

This study investigates the dynamic and causal effects of climate stress and Artificial Intelligence-enabled agricultural monitoring on cultivated land quality, productivity, and sustainability in Saudi Arabia. Using a balanced panel of region–crop observations covering 13 administrative regions and six major crops over the period 2010–2024, the analysis integrates high-resolution climate variables with remote sensing-based indicators, including the Normalized Difference Vegetation Index, Enhanced Vegetation Index, Net Primary Productivity, Water-Use Efficiency, and crop water productivity. A comprehensive econometric framework combining the System Generalized Method of Moments, Difference-in-Differences, and event-study approaches is employed to address persistence, endogeneity, and causal identification. The results show that water availability—captured by soil moisture and precipitation—significantly enhances cultivated land outcomes (coefficients ≈ 0.05–0.11), while heat stress and wind speed exert strong negative effects (coefficients ≈ −0.04 to −0.12), highlighting the vulnerability of arid agricultural systems. Artificial Intelligence-enabled monitoring and smart irrigation adoption consistently improve land quality and productivity, with the largest gains observed in water-use efficiency and crop water productivity. Artificial Intelligence adoption increases water-use efficiency and crop water productivity by approximately 8–10%, while heat stress reduces vegetation indicators by about 9–12%. Event-study evidence confirms that these effects emerge after adoption and persist over time, supporting a causal interpretation. Overall, the findings demonstrate that AI technologies mitigate climate stress primarily through improved water management and adaptive decision-making. The study provides policy-relevant insights aligned with Saudi Vision 2030, emphasizing digital agriculture as a key instrument for sustainable cultivated land governance, climate adaptation, and food security in water-scarce environments.

Resources doi: 10.3390/resources15030043

Authors: Crescenzo Pepe Silvia Maria Zanoli

In order to pursue the energy goals defined for 2030 and 2050 [...]

Resources doi: 10.3390/resources15030042

Authors: Dritan Topi Aleksander Petre

The olive oil extraction industry produces large amounts of olive pomace and wastewater, both of which contain high levels of pollutants. In Albania, olive oil production has increased, while by-product challenges persist. Uncontrolled wastewater discharge and pomace burning have caused environmental issues and inefficient resource use. This study combines published data with field information to examine country pomace utilization and wastewater management. The regional distribution of extraction units and production volumes was analyzed to identify mismatches between processing capacity and output. The findings reveal discrepancies between official statistics and field data. Regional analysis highlights notable imbalances between the number of olive mills and their production volumes, especially in Elbasan, Fier, Vlora, and Berat. Projections, assuming three-phase technology, indicate increased generation of olive pomace and wastewater, thereby raising environmental risks associated with wastewater disposal. The potential for olive pomace oil production was estimated to reach up to 1600 tons. While progress has been made in establishing a pomace oil extraction plant, infrastructure gaps, weak regulation, and limited producer awareness need to be addressed to convert by-products into valuable resources and help Albania’s olive oil sector achieve sustainability goals.

Resources doi: 10.3390/resources15030041

Authors: Enola Brecht Peter Kovalsky

New Zealand’s kiwifruit and apple industries generate substantial quantities of organic residues during thinning and harvest, much of which is composted or disposed of in landfills due to logistical constraints. This study evaluates the potential of these residues as feedstock for biomethane production via anaerobic digestion (AD), followed by hydrogen generation through steam methane reforming (SMR). Two feedstock mixtures were examined: a 50:50 kiwifruit–apple blend and a 40:40:20 kiwifruit–apple–potato mixture, designed to mitigate acidification. Cow manure served as a cost-effective inoculum. Physicochemical analysis confirmed high moisture and volatile solids content, indicating strong biodegradability, although low nitrogen content suggests the need for co-digestion in full scale systems. Biomethane potential (BMP) tests yielded up to 45 mL CH4/gVS at an ISR of 4, corresponding to 46.5% carbon conversion. Scaling to an annual waste volume of 476 t suggests a potential biomethane yield of approximately 18,000 m3. SMR simulations demonstrated technical feasibility, with methane conversion increasing from 46% under baseline conditions to >85% under optimized steam to carbon ratios and residence times. Hydrogen yields of ~7600 m3/year were estimated. This study provides a practical foundation for valorizing fruit waste into renewable biomethane and hydrogen, supporting New Zealand’s circular economy and decarbonization goals.

Resources doi: 10.3390/resources15030040

Authors: Ludmilla Ferreira Justino Alexandre Bryan Heinemann David Henriques da Matta Luís Fernando Stone Felipe Waks Andrade Silvando Carlos da Silva

Addressing the intertwined challenges of food security and climate vulnerability requires robust and regionally tailored strategies for staple crops such as common beans. Although adjusting sowing dates is a key adaptive practice, spatio-temporal climate variability complicates the identification of optimal planting windows. This study integrates crop modeling with Functional Data Analysis (FDA) to quantify sowing-date-dependent yield losses for rainfed common beans across Central-Southern Brazil. The CSM-CROPGRO-Dry Bean model, driven by long-term climate data (1980–2016), soil properties, and management practices, was used to simulate yields for the BRS Estilo cultivar. FDA was subsequently applied to cluster yield-loss curves across municipalities and growing seasons, generating representative regional risk profiles. The results reveal clear spatial patterns. During the wet season, earlier sowing minimizes losses in Goiás, Minas Gerais, and western Paraná, whereas later sowing is beneficial in São Paulo, Santa Catarina, and eastern Paraná. In the dry season, earlier sowing consistently reduces losses across most regions. These patterns are primarily driven by water deficits and suboptimal temperatures during critical phenological phases. The resulting spatio-temporal sowing calendar provides an evidence-based decision-support tool to help farmers mitigate climatic risks. Moreover, it offers a scientific foundation for policymakers to refine sustainable management practices, improve crop insurance design, and enhance agricultural resilience and productivity under increasing climate uncertainty.

Resources doi: 10.3390/resources15030039

Authors: Marcela Mariel Maldonado-Villegas Alondra del Pilar Castillo-Gutiérrez Blanca Catalina Ramírez-Hernández Paulina Beatriz Gutiérrez-Martínez Eduardo Juárez-Carrillo Javier García-Velasco Sara Villanueva-Viramontes Héctor Leal-Aguayo Jonathan Manuel López Carlos Alvarez-Moya Mónica Reynoso-Silva

Lake Chapala is the main freshwater reservoir in Mexico and faces notable environmental pressure associated with urban, industrial, and agricultural activities, with documented evidence of heavy metal contamination. Thus, the artisanal fishers from Lake Chapala occupy a strategic position for understanding the socio-environmental dynamics of this lacustrine system. The objective of this study was to analyze their perceptions of pollution in Lake Chapala and the health risks associated with heavy metal contamination, with particular emphasis on the consumption of charal (Chirostoma spp.). Based on the results, 70% of fishers agreed that Lake Chapala is polluted, and 50% identified solid waste as the main source of contamination. Regarding water quality, 41% considered that it had not changed in recent years, while 37% perceived that it had deteriorated. With respect to heavy metals, 50% reported being aware of their presence in the lake; however, slightly more than 50% expressed concern about the possibility that charal could be contaminated. Fishers acknowledged the environmental pressure faced by Lake Chapala but prioritized risks based on visibility and their everyday experiences. Incorporating the perceptions of key stakeholders is essential for addressing socio-environmental problems, strengthening environmental communication and public health strategies, and effectively managing this lacustrine system.

Resources doi: 10.3390/resources15030038

Authors: Amina Hamdouni

Water scarcity poses a critical challenge to sustainable agricultural development, particularly in arid regions such as Saudi Arabia. This study examines whether AI-compatible smart irrigation, digital water monitoring, and integrated water resource management (IWRM) are associated with improvements in agricultural water sustainability. Using a regional–crop panel dataset covering 13 Saudi administrative regions and six major crops over the period 2010–2024, the analysis evaluates their relationships with water-use efficiency, crop water productivity, and crop yield. To address persistence, endogeneity, and unobserved heterogeneity, the study employs a comprehensive multi-method empirical strategy combining dynamic panel models (System GMM), difference-in-differences, and event-study designs. The results provide internally consistent and empirically robust evidence in support of the proposed hypotheses. AI-compatible smart irrigation is positively and significantly associated with improvements in agricultural water efficiency and productivity, with effects that strengthen over time, reflecting gradual technology assimilation and learning processes. These findings capture the performance gains from irrigation modernization that enables data-driven and algorithm-supported decision-making, rather than the direct causal impact of autonomous artificial intelligence deployment. Integrated water resource management independently exhibits a positive association with higher agricultural performance, underscoring the importance of coordinated governance alongside technological adoption. Digital water monitoring shows a positive and statistically significant relationship with all outcome measures and appears to reinforce the effectiveness of both AI-compatible irrigation and integrated water governance. Robustness analyses excluding extreme drought years confirm that these relationships reflect persistent efficiency patterns rather than transitory climatic shocks. Overall, the findings provide context-specific and methodologically rigorous evidence that AI-compatible irrigation, digital monitoring, and integrated water governance operate as complementary components of agricultural water sustainability in a highly water-scarce economy, offering evidence-informed and policy-relevant insights, aligned with Saudi Vision 2030.

Resources doi: 10.3390/resources15030037

Authors: Valentino Sandoval-Peraza Octavio Ramos-Ocharán Karla Alcalá-Escamilla Magdalena Molina-Rosas Luis Chel-Guerrero David Betancur-Ancona

Global challenges in food security and sustainable biomass management highlight the need to diversify resource streams that can supply accessible, safe, and environmentally responsible protein. Delonix regia (flamboyant) seed germ (FG) represents an abundant but largely underutilized biomass resource in tropical and subtropical regions, where its seeds are routinely discarded as green waste. This study assesses the resource potential of FG by evaluating its nutritional composition, safety profile, and suitability for integration into sustainable protein provision strategies. The FG fraction was recovered from locally available seed residues and analyzed to determine their proximate composition, essential amino acid profile, and antinutrient content, providing insights into the qualitative attributes of this emerging resource. Safety was examined through in vivo acute toxicity assays and detailed histopathological evaluation of hepatic and renal tissues of CD1/ICR strain female mice, which revealed no morphological indicators of toxicity, inflammation, or cellular damage. The results indicate that FG contains a high protein concentration (78.35%) with a favorable essential amino acid pattern, supporting its potential as a renewable and locally accessible plant-based protein source. Beyond its nutritional value, the valorization of FG contributes to resource efficiency, waste-to-value pathways, and circular economy approaches by transforming an abundant municipal biomass residue into a functional component for sustainable food systems. Overall, the study underscores the feasibility of integrating FG into resource diversification strategies, enhancing protein availability while reducing environmental burdens associated with biomass disposal.

Resources doi: 10.3390/resources15030036

Authors: Katarzyna Kocur-Bera

Reducing greenhouse gas emissions and promoting biodiversity are currently among the key orientations of European climate policy. The increase in atmospheric greenhouse gas concentrations (including carbon dioxide) is caused, among others, by the environmental impacts of human activities. Carbon capture and storage are at the heart of climate and energy security. This study aimed to analyze scenarios that assume various ways of using and managing common land. Common land is found in many countries. However, the legal status of these lands varies. This status often determines how the land can be managed. The article uses online surveys (CAWI), the land morphology concept (LMC), the scenario method, and an analysis of precedent events. The scenarios considered the stakeholders in the process. The results demonstrated that the optimal approach is to use regenerative agriculture with cover cropping. The diagnosis of precedent events showed that this method of use may be difficult to apply under local conditions due to low social involvement in the process of obtaining autonomy and self-determination by the parties entitled to common land, as well as by national-level authorities.

Resources doi: 10.3390/resources15030035

Authors: Rosaura Hernández-Montelongo Humberto Gutiérrez-Pulido Juan Paulo García-Sandoval Abraham Gabriel Alvarado-Mendoza

The improper management of fats, oils, and grease (FOG) from food services is a major cause of sewer blockages and environmental damage. This study examines FOG management in the restaurant sector of the Guadalajara Metropolitan Area, Mexico, from three complementary perspectives: the performance of the authorized formal collection system, management practices in food establishments, and the physicochemical characteristics of grease trap residues. These perspectives were addressed using official administrative records and reports from environmental authorities, structured surveys applied to kitchen staff, and laboratory analyses of grease trap samples collected in restaurants. The results reveal important institutional and structural constraints affecting FOG management. Only a limited number of authorized collectors operate actively, serving a small fraction of potential generators, while most food service establishments are micro- or small-sized businesses with limited technical and financial capacity to comply with regulations. A large portion of the sector consists of small, low-cost food service establishments with intensive oil use (e.g., street food vendors, sandwich shops, and set-menu restaurants), which contribute to widespread oil reuse and inadequate disposal practices. Laboratory analyses showed a high free fatty acids (FFAs) content and compositional profiles consistent with repeated oil use, with negative implications for sewer systems and waste management. Overall, the findings highlight the need for stronger regulatory enforcement, collection schemes tailored to micro-scale generators, and awareness campaigns while also indicating opportunities for FOG valorization within circular economy approaches, particularly through energy recovery pathways.

Resources doi: 10.3390/resources15030034

Authors: Anete Meija Uldis Spulle Ignazia Cuccui Aigars Paze Janis Rizikovs

This study evaluates the environmental performance of plywood manufactured from thermally modified birch veneers using the Thermovuoto® process, bonded with a birch bark–derived suberinic acids adhesive. Framed within the context of sustainable materials development and the circular bioeconomy, the research examines the potential of bio-based adhesive systems as alternatives to conventional phenol–formaldehyde resins. A cradle-to-grave life cycle assessment (LCA) was performed, encompassing birch bark harvesting, adhesive production, veneer thermal modification, plywood manufacturing, distribution to the customer, and end-of-life management. Environmental impacts were modelled using openLCA 2.4 in combination with the Ecoinvent 3.11 database, in accordance with ISO 14040 and ISO 14044, applying the ReCiPe 2016 v.1.03 (H) midpoint life cycle impact assessment method. The results indicate that the birch bark extraction stage, particularly ethanol use derived from potato fermentation, constitutes the dominant contributor across all assessed impact categories. Overall, the LCA outcomes suggest that thermally modified, suberinic-acid-bonded birch plywood represents a promising niche bio-based material, with clear potential for further environmental improvement through process optimization.

Resources doi: 10.3390/resources15020033

Authors: Hiba Chebli Giovanna Dragonetti Abdelouahid Fouial

Agrivoltaic Systems (AV) constitute a viable alternative to mitigate land-use competition by enabling the simultaneous production of agricultural crops and solar photovoltaic energy. However, the heterogeneous shading and microclimatic modifications induced by AV systems can alter solar radiation, crop physiological performance, and, consequently, its biomass. This study evaluated the effects of two static ground-mounted AV systems—semi-transparent (ST) and conventional opaque (CON) panels—on the growth, physiology, soil water variations, and yield of Arugula (Eruca vesicaria) cultivated in southern Italy from August to October 2022; compared with an open-field control (REF). Daily soil temperature and water content were monitored, alongside leaf-level gas exchange measurements at three vegetative stages. Global solar radiation was reduced by 70% under ST and 80% under CON, reducing Photosynthetically Active Radiation (PAR), transpiration, and net photosynthesis, while leaf water use efficiency remained comparable to REF. Sequential harvests showed that although yields were consistently highest in REF, ST 50% and CON 50% exhibited partial recovery in fresh and dry biomass by the third cutting, reflecting the mitigating effect of seasonal temperature declines on shading. Notably, soil water uniformity improved under AV systems, reaching 90% under ST and 94% under CON compared with 85% in REF, due to reduced evaporative losses and enhanced lateral soil water redistribution. Overall, while AV-induced shading limits radiation and yield in short-cycle leafy arugula, microclimate modulation under AV systems can enhance soil water distribution and partially buffer growth under less favorable seasonal conditions. These findings highlight the trade-offs between crop productivity and resource-use efficiency in AV systems and emphasize the importance of tailoring their design to crop type and local climatic conditions, providing valuable guidance for future experimental research and for policymakers aiming to support sustainable agrivoltaic deployment.

Resources doi: 10.3390/resources15020032

Authors: Tatyana Kukharova Pavel Maltsev Sergey Abramkin Igor Novozhilov

Due to the depletion of traditional hydrocarbon fields in the Russian Federation, the development of structurally complex fields is currently a pressing issue. The challenge is to ensure a high gas recovery factor (GRF). This paper presents a comprehensive analysis of the scientific and technical literature, including a classification of factors affecting gas recovery; a review of existing approaches to neutralising their impact; and the identification of unsolved challenges and promising research areas at the pore, layer, and field scales. The study identified and classified the key factors affecting gas recovery. It was determined that, from the standpoint of automating gas production processes, changes in reservoir pressure are the key factor influencing gas recovery. Promising solutions are proposed, including the implementation of digital technologies, machine learning, proxy models, and the concept of digital twins. Unresolved challenges and research gaps are identified. The study results generalise existing knowledge on the challenges and promising approaches to improving the efficiency of developing the resource potential of fields with complex geological structures.

Resources doi: 10.3390/resources15020031

Authors: Samia Rahman Moon Md. Mahbubur Rahman Aminur Rahman Aftab Ahmad Khan Muhammad Altaf Nazir Md. Ariful Islam Md. Abdulla-Al-Mamun

Water resources are the key to human well-being, economic growth, and ecosystems, but the growing pressure on them is caused by climate change, high population rates, industrial development, and unsustainable consumption. The quality of water degradation, overexploitation of groundwater, and the growing water scarcity pose a significant threat to the sustainability of the environment, as well as international security. This review examines key drivers and challenges in water resources management, such as climate variability, pollution by traditional and emerging contaminants, lack of governance, and cross-boundary conflicts. It also discusses innovative solutions like advanced water treatment technologies, reuse and recycling systems, nature-based approaches, smart monitoring networks, and integrated policy frameworks that can contribute to a circular and sustainable water economy. In addition, the interdisciplinary approach, climate-adaptive infrastructure, enhanced governance, and increased international collaboration are also highlighted as necessary to attain resilient and equitable water systems. Through a balance between policy innovation and community participation and technological progress, water resource management will be able to shift towards ensuring environmental sustainability and also towards enhancing the implementation of the United Nations Sustainable Development Goals.

Resources doi: 10.3390/resources15020030

Authors: Idalina Domingos Miguel Ferreira José Ferreira Bruno Esteves

Olive trees cultivated in the Viseu region (Portugal) were used in the present work. This study investigates the compositional characteristics and hydrothermal behavior of olive branches (OB) and olive leaves (OL) under autohydrolysis, aiming to assess their potential for biorefinery applications. Chemical analysis revealed that during autohydrolysis (140–180 °C, 15–30 min), OL exhibited greater solubilization than OB, consistent with their higher extractive content. Increasing the temperature promoted selective hemicellulose removal and partial cellulose degradation, leading to a relative enrichment of lignin in the solid residues. Nevertheless, the cellulose content of olive branches for 180 °C and 30 min hydrolysis increased. Fourier transform infrared spectroscopy confirmed progressive structural rearrangements, including enhanced hydroxyl exposure, carbonyl formation, and lignin condensation, indicating the transformation of the solid phase toward more aromatic and thermally stable structures. Autohydrolysis slightly increased the higher heating value of the solid residues while acid-catalyzed liquefaction markedly increased, exceeding those of both native and technical lignins. These results suggest extensive carbon enrichment and oxygen removal during liquefaction. Overall, autohydrolysis proved effective for hemicellulose solubilization and sugar recovery, while liquefaction favored energy densification and lignin condensation. The distinct behaviors of OB and OL highlight the importance of tailoring processing conditions to each feedstock type. Both materials show strong potential as renewable resources for bioenergy and value-added carbon-based products within an integrated olive biomass biorefinery framework.

Resources doi: 10.3390/resources15020029

Authors: Abdelhalim S. Mahmoud Hanaa A. El-Dokouny Mai A. El-Lithy Ali Shebl Maher Dawoud Farouk Sayed Mohamed M. Ghoneim

This study investigates the genesis of gold mineralization at the Rodruin prospect in the central Eastern Desert (CED) of Egypt, with the aim of constraining the relative contributions of metamorphic and magmatic fluids to ore formation. Gold mineralization at Rodruin is hosted by quartz–carbonate veins emplaced within a shear zone that transects low-grade metasedimentary sequences intruded by Ediacaran post-tectonic granitoids. It exhibits characteristics transitional between orogenic turbidite-hosted and polymetallic vein-type mineralization. Although metamorphic devolatilization is interpreted to have generated the dominant ore-forming fluids, adjacent granitoid intrusions acted primarily as a thermal engine, with only a limited direct input of magmatic-hydrothermal fluids. This interpretation is supported by the occurrence of magmatic-affiliated mineral inclusions (monazite, cassiterite, and zircon) coupled with generally low concentrations of trace elements typically enriched in granitic magmatic-hydrothermal fluids (Sb, Bi, Mo, W, Sn, Nb, and Ta), collectively indicating a subordinate magmatic contribution. Rare earth element (REE) patterns of the ore samples closely resemble those of the nearby granitoids, displaying LREE enrichment; however, a distinct positive Eu anomaly is restricted to the ore assemblages and is attributed to hydrothermal feldspar alteration supporting magmatic involvement in ore formation. Carbon and oxygen isotope compositions (δ13C = −6.6 to −2.36‰; δ18O = +15.7 to +19.7‰), together with REE signatures comparable to primitive mantle values and textural evidence for synchronous sulfide–carbonate precipitation, manifested by rhythmic banding of carbonates and sulfides unequivocally indicate a hydrothermal–metasomatic origin. Collectively, these lines of evidence support a hybrid metamorphic–magmatic model in which gold and associated base metals were predominantly transported by metamorphic fluids, whose mobilization and focusing were enhanced by the thermal influence of Younger granitic intrusions, whereas magmatic-hydrothermal fluids contributed only a minor proportion to the overall metal budget.

Resources doi: 10.3390/resources15020028

Authors: Natalia Salgado-Aristizabal Juan Galvis-Nieto Danya Jurado-Erazo Carlos Cardona-Alzate Carlos Orrego-Alzate

Rice processing generates substantial residual biomass globally—about 170 million tons of husk, 62–71 million tons of bran and 23–39 million tons of broken rice annually—which remains largely underutilized and creates environmental burdens and lost economic opportunities. This study was conducted to address the necessity for integrated sustainability assessments of rice mill biorefineries. The focus of this study is on transitioning from a global context of residual biomass generation to a local-scale application in small and medium mills (100–300 tons/day). We apply a resource-centric framework, combining process simulation, techno-economic analysis, and Life Cycle Assessment (LCA—selected for its capacity to quantify trade-offs and avoid burden-shifting across multiple impact categories) with Social-LCA. Five valorization scenarios are assessed. Results demonstrate that biorefinery pathways fundamentally alter supply provision: husk cogeneration boosts energy self-sufficiency (SGI = 12.54), displacing fossil fuels, while silica and nutrient recovery create new, local material flows, substituting for virgin resources. However, chemically intensive routes increase human toxicity impacts (up to 4.0 × 10−1 kg 1,4-DB eq/kg) despite product diversification. Social analysis reveals a tension between worker preferences for advanced technology and community priorities for low-chemical, employment-generating options. Probabilistic sensitivity analysis identifies a diversified configuration (oil, flour, feed, cogeneration) as most robust, optimizing overall resource productivity and circularity. This work transitions the conceptual model of a rice mill from a linear processor to a multi-output bio-resource hub, offering actionable pathways to enhance regional energy, mineral, and nutrient security through circular economy implementation.

Resources doi: 10.3390/resources15020027

Authors: Mariusz Ptak Teerachai Amnuaylojaroen Bogumił Nowak Soufiane Haddout Mariusz Sojka

The emission of greenhouse gases associated with the combustion of hydrocarbons is a key factor in climate change, and in this context, increasing emphasis is being placed on the development of clean energy sources. The novel contribution of the article lies in identifying the energy potential of surface waters within energy systems transitioning away from fossil fuels. In the case of Poland, whose energy system has been based on coal for many decades, there are still many opportunities to expand energy production from renewable sources. One such source is the heat contained in surface waters. The research presented in this article focuses on the thermal structure of nine stratified lakes in Poland, examining changes over time and across different spatial profiles. Considering all temperature profiles, values ranged from 8.3 °C in May to 10.1 °C in September. In general, water warming occurs from May to the July–August transition, reaching a maximum of over 6 °C, while cooling takes place in the later phase of the analyzed season at a lower level, not exceeding 6 °C. It was found that the most thermally stable part of the water body was the layer between 15 m in depth and the bottom of the lakes, for which the heat resources were calculated. Using the basic physical properties of water, the amount of heat for this layer was determined. Assuming that technological processes do not reduce the water temperature below 4 °C (maximum water density), the hypothetical amount of available energy ranges from 630 to 101,000 MWh. The results indicate the high energy potential of lakes, which could be utilized in the future, provided further legal and economic analyses are conducted for specific cases. The study highlights the need to expand the long-term thermal monitoring of lakes, covering their entire vertical structure. Priority for such measurements should be given to lakes located near human settlements, as these have the highest potential for practical use.

Resources doi: 10.3390/resources15020026

Authors: Sebastião De Hermínia Lucas Vilanculos Sosdito Estevão Mananze Mário Campos Cunha

This study analyzes forest cover change patterns, agricultural expansion, and economic growth in Mozambique from 2001 to 2024, using remote sensing data from Global Forest Watch and socioeconomic indicators from the World Bank and FAO. Mozambique lost approximately 4.6 million hectares of forest during the analyzed period, with agriculture accounting for 97.4% of total deforestation. GDP per capita increased by 90.5%, while cultivated area expanded by 116.4%. However, agricultural productivity declined by 25.3%, revealing a paradox: production growth relied on extensive land expansion rather than intensification. Statistical analysis of three 8-year sub-periods identified significant differences in GDP per capita, agricultural GDP per capita, population, and agricultural employment (p < 0.001), but agricultural deforestation remained statistically stable (p = 0.065). This pattern suggests premature decoupling between economic growth and deforestation at income levels (USD 604) substantially below historical Environmental Kuznets Curve thresholds (USD 8000–10,000). However, this decoupling is fragile, driven by capital-intensive extractive sectors that generate GDP growth without absorbing rural populations. The persistence of extensive agricultural expansion, combined with weak governance, demographic pressures, and climate variability, indicates that observed stabilization represents an initial, vulnerable phase requiring structural transformation through agricultural intensification, inclusive industrialization, land tenure reform, and climate resilience building.

Resources doi: 10.3390/resources15020025

Authors: Gennady Stroykov Andrey Lebedev Aida Belous Ekaterina Kolganova

Many companies in the mining industry include decarbonization of production among their key strategic goals as part of their internal sustainability strategy. This need is driven by a number of factors: stricter regulation in the area of carbon footprint (introduction of carbon taxes, emissions quotas, reporting requirements); sustained growth in demand for electricity and rising market prices; economic feasibility—the need to optimize operating costs and improve energy efficiency. This study provides a comprehensive technical and economic justification for implementing a hybrid power supply system—combining a solar power plant (SPP) and a gas engine power plant (GPP)—at Solidcore Resources’ Varvarinsky hub in Kazakhstan. The methodology includes modeling the energy balance of the real asset (156.9 GWh of annual energy consumption), calculating the output of a 22.6 MW SPP based on local GHI/PR/η parameters, forming and determining the adaptability coefficient Kₐ (proportion of PV in total monthly electricity generation), conducting an economic assessment (NPV, payback period, sensitivity), and inventorying CO2 emissions under Scope 1–2. The SPP provides approximately 41.3 GWh of electricity generation per year, with an average annual Ka = 0.263; the 40 MW installed capacity of the gas piston power plant covers the residual demand, forming a stable daily and seasonal balance. The project demonstrates a positive NPV (After Tax) = USD 23.65 million with an estimated payback period of 10 years, while the cost of energy in extraction and processing is reduced by almost three times, and the total reduction in CO2 emissions will be 51%. Thus, hybridization of energy supply systems is a practical compromise between reliability and decarbonization. Determining the adaptability coefficient Ka allows the flexibility of the system to be taken into account, shows how effectively the new energy system uses renewable energy sources, and can be used to optimize the operation of the energy system to achieve the company’s internal sustainable development goals.

Resources doi: 10.3390/resources15020024

Authors: Irmadi Nahib Yudi Wahyudin Widiatmaka Widiatmaka Suria Tarigan Wiwin Ambarwulan Fadhlullah Ramadhani Bono Pranoto Nunung Nugroho Turmudi Turmudi Darmawan Cahya Mulyanto Darmawan Suprajaka Suprajaka Jaka Suryanta Bambang Winarno

Rapid land use and land cover (LULC) changes in densely populated watersheds pose serious challenges to the sustainability of ecosystem services (ES), yet their spatially explicit economic consequences remain insufficiently understood. This study analyzes the spatio-temporal dynamics of LULC and ecosystem service values (ESVs) in the Citarum Watershed, Indonesia, one of the country’s most critical and intensively transformed watersheds. Multi-temporal Landsat imagery from 2003, 2013, and 2023 was classified using a Random Forest algorithm, while future LULC conditions for 2043 were projected using a Multi-layer Perceptron–Markov Chain (MLP–MC) model under three scenarios: Business-as-Usual (BAU), Protecting Paddy Field (PPF), and Protecting Forest Area (PFA). ESVs were quantified at multiple spatial scales (county, 250 m grids, and 100 m grids) using both the Traditional Benefit Transfer (TBT) method and a Spatial Benefit Transfer (SBT) approach that integrates biophysical indicators with socio-economic variables. The contribution of LULC transitions to ESV dynamics was further assessed using the Ecosystem Service Change Intensity (ESCI) index. The results reveal substantial historical forest and shrubland losses, alongside rapid expansion of settlements and dryland agriculture, indicating intensifying anthropogenic pressure on watershed functions. Scenario analysis shows continued degradation under BAU, limited mitigation under PPF, and improved forest retention under PFA; although settlement expansion persists across all scenarios. Total ESV declined from USD 2641.33 million in 2003 to USD 1585.01 million in 2023, representing a cumulative loss of 46.13%. Projections indicate severe ESV losses under BAU and PPF by 2043, while PFA substantially reduces, but does not eliminate economic degradation. ESCI results identify forest and shrubland conversion to settlements and dryland agriculture as the dominant drivers of ESV decline. These findings demonstrate that integrating multi-scenario LULC modeling with spatially explicit ESV assessment provides a more robust basis for ecosystem-based spatial planning and supports sustainable watershed management under increasing development pressure.

Resources doi: 10.3390/resources15020023

Authors: Edoardo Bigolin Milena Rajić Tamara Rađenović Serena Caucci Giannis Adamos Marco Frey

Ecolabelling has emerged as a key instrument to communicate environmental performance to consumers, particularly in the agri-food sector where resource use and ecological pressures are highly interlinked. Conventional Life Cycle Assessment (LCA)-based ecolabels often suffer from methodological discretion, lack of territorial specificity, and limited consumer trust. This study investigates how the Water–Energy–Food–Ecosystem (WEFE) Nexus could be integrated into LCA-based ecolabelling, with a specific focus on pasta production as a representative case in the food industry. Indicators were collected from recent literature on LCA and Nexus applications, selected for simplicity and clear attribution to one WEFE dimension, and then evaluated by experts from COST Action CA20138 (NexusNet) through a two round Delphi protocol. The process yielded 23 indicators distributed across the four dimensions, which were subsequently compared with six Environmental Product Declarations to assess data availability and compatibility. The results suggest that many indicators can be computed with standard LCA inventories, while the Nexus perspective adds value by capturing multidimensional impacts and regional resource pressures. Further refinement and empirical testing are expected to enhance the framework’s applicability, but the findings already indicate that incorporating WEFE-based indicators into pasta ecolabelling could represent a promising pathway to improve analytical depth and consumer relevance, aligning circular economy principles with corporate assessment practices.

Resources doi: 10.3390/resources15020022

Authors: João Garcia Rafael Lima Pedro Resende André Rosa Alexandre Afonso Leandro Morais

The lack of interest in the reuse of phosphorus in agriculture is mainly due to the high abundance of pathogens, organic pollutants, microplastics, and possibly toxic metals. Therefore, different forms of treatment are necessary to take advantage of phosphorus recovery potential, one of which is the use of ash from incinerated/calcined biological sludge. A high rate of conversion of the non-apatite inorganic phosphorus fraction into apatite phosphorus was obtained in this study because of the use of commercially pure CaO additive in the dry sludge calcination tests, which is more bioavailable to plants. The obtained phosphorus pentoxide content ranged from 12 to 17%, surpassing several phosphorus-based raw materials and fertilizers. In addition, the ashes have been shown to contain toxic metals far below those recommended by Brazilian and international environmental legislation, so they can be applied directly to the soil for crop fertilization, or be used in P extraction and separation technologies for fertilizer production.

Resources doi: 10.3390/resources15020021

Authors: Kwan Tun Lee Jen-Kuo Huang Pin-Chun Huang

This study presents an integrated decision support system (DSS) designed to optimize real-time reservoir operation during typhoons by balancing flood control and water supply. The system combines ensemble quantitative precipitation forecasts (QPF) from WRF/MM5 models, a physically based rainfall–runoff model (KW-GIUH), and a three-stage optimization algorithm for reservoir release decisions. Eighteen ensemble rainfall members are processed to generate 6 h inflow forecasts, which serve as inputs for determining adaptive outflow strategies that consider both storage requirements and downstream flood risks. The DSS was tested using historical typhoon events—Talim, Saola, Trami, and Kong-rey—at the Tseng-Wen Reservoir in Taiwan. Results show that the KW-GIUH model effectively reproduces hydrograph characteristics, with a coefficient of efficiency around 0.80, while the optimization algorithm successfully maintains reservoir levels near target storage, even under imperfect rainfall forecasts. The mean deviation of reservoir water levels from the recorded to the target values is less than 0.18 m. The system enhances operational flexibility by adjusting release rates according to the proposed outflow index and flood-stage classification. During major storms, the DSS effectively allocates storage space for incoming floods while maximizing water retention during recession periods. Overall, the integrated framework demonstrates strong potential to support real-time reservoir management during extreme weather conditions, thereby improving both flood mitigation and water-supply reliability.

Resources doi: 10.3390/resources15020020

Authors: Juliana Melo Teresa Dias Ana M. Santos Sanaa Kamah Silvia Castillo Khalid Akdi Cristina Cruz

Drought poses a major challenge for global agriculture, demanding strategies that improve crop resilience while safeguarding water and nutrient resources. Plant growth-promoting rhizobacteria (PGPR)-based biostimulants offer a sustainable approach to enhance resource-use efficiency under water-limited conditions. This study evaluated two commercial PGPR biostimulants applied to maize (Zea mays L.) and tomato (Solanum lycopersicum L.) seedlings grown under well-watered (80% field capacity) and water-stressed (40% field capacity) conditions. Both products improved plant growth and physiological performance, although responses were crop-specific. Inoculated tomato seedlings accumulated up to 35% more shoot biomass under optimal watering (1.6 g in non-inoculated seedlings compared with 2.5 g in inoculated seedlings), whereas maize maintained biomass production under drought, consistent with its higher intrinsic water-use efficiency, showing increases of approximately 50% (well-watered: 0.5 g versus 0.8 g; water-stressed: 0.3 g versus 0.7 g in non-inoculated and inoculated seedlings, respectively). Biostimulant application enhanced the acquisition and internal utilization of essential mineral resources, increasing leaf concentrations of (i) the macronutrients P (up to 300%), K (up to 70%), Mg (up to 220%), and Ca (up to 85%), and (ii) the micronutrients B (up to 400%), Fe (up to 260%), Mn (up to 240%), and Zn (up to 180%). Maximum nutrient increases were consistently observed in water-stressed maize seedlings inoculated with biostimulant 2. Antioxidant activities, particularly ascorbate peroxidase and catalase, increased by 20–40%, indicating more effective mitigation of oxidative stress. Principal component analysis revealed coordinated adjustments among growth, nutrient-use efficiency, and physiological traits in inoculated plants. Overall, PGPR-based biostimulants improved early drought tolerance and resource-use efficiency, supporting their potential as sustainable tools for climate-resilient agriculture. Field-scale studies remain necessary to confirm long-term agronomic benefits.

Resources doi: 10.3390/resources15010019

Authors: Randima De Silva Prasanna Divigalpitiya

Rapid urban growth in many Global South cities strains waste systems and slows the shift to circular economy (CE) practice. Colombo, Sri Lanka, exemplifies this challenge, where overstretched state-led services coexist with neighborhood groups, NGOs, and informal collectors driving circular activities. This study adopts a layered social network diagnostic framework to examine how community-based waste management networks operate and how they might be reshaped to enable a city-wide CE. Using survey and interview data from 185 actors, information-sharing, collaboration, and resource-exchange networks are analyzed separately and in combination. The results reveal three principal findings: (i) Social-capital forms operate largely in parallel, with limited conversion between information, collaboration, and material exchange; (ii) the network exhibits “thin bridges and thick clusters,” in which a small number of NGO hubs mediate most cross-cluster connectivity; (iii) layers operate with mismatched coordination logics, producing gaps between awareness, collective action, and resource mobilization. As a result, ideas circulate widely but rarely translate into joint projects, local teams coordinate effectively yet remain isolated, and material flows depend on a narrow and fragile logistics spine. By diagnosing these structural misalignments, this study demonstrates a key novelty: scalable circular economy adoption depends not only on technology and policy but also on the design and alignment of underlying coordination networks.

Resources doi: 10.3390/resources15010018

Authors: Ionela Gavrila-Paven Ramona Giurea Elena Rada

This study provides an integrated assessment of progress toward Sustainable Development Goal 12 (Responsible Consumption and Production) by applying a multivariate, indicator-based framework to a comprehensive set of EU-27 performance metrics. Rather than proposing new indicators, the analysis advances SDG 12 monitoring by systematically integrating official indicators of material efficiency, circularity, waste generation, consumption-based environmental pressure, and environmental economic activity with key cross-sectoral drivers. Using harmonized statistical data, the study examines raw material consumption, circular material use rates, hazardous chemical consumption, consumption footprints, hazardous waste generation, and the economic value added of the environmental goods and services sector, complemented by energy productivity and average CO2 emissions from new passenger cars. Through z-score normalization, correlation analysis, and exploratory factor analysis, the research identifies structural interdependencies and latent systemic regimes that characterize responsible consumption and production dynamics in the EU. The results reveal a persistent divergence between efficiency- and circularity-oriented improvements and ongoing material and waste pressures, highlighting structural constraints within current sustainability pathways. By offering a replicable and integrative analytical framework, the study contributes to the literature by supporting evidence-based policymaking and identifying priority areas for advancing resource efficiency and circular economy transitions.

Resources doi: 10.3390/resources15010017

Authors: Josephine Mutwale Ephraim Zulu Francis Mulolani Sambo Lyson Zulu

This study examines the social factors shaping solar energy transitioning in Zambia’s mining sector, a key contributor to the national resource economy. It focuses on how policies, incentive systems, communication channels, training and skills development, and stakeholder engagement and partnership influence the sector’s readiness to adopt solar energy and support more reliable operations. A quantitative design was used, with a 5-point Likert-scale questionnaire administered to 192 respondents from mining companies, regulatory bodies, energy suppliers and local authorities. Data were analysed using descriptive statistics, reliability tests and hierarchical regression. The results show that stakeholder engagement and partnership and incentive systems are the strongest predictors of transition intentions, underscoring their role in improving energy security and supporting sustainable production. Policies, communication and training had weaker effects, indicating the need for stronger institutional coordination and targeted capacity building. Overall, the findings illustrate how social conditions shape renewable energy adoption and contribute to more resilient mining activities.

Resources doi: 10.3390/resources15010016

Authors: Luis López-Sosa Carlos García Ana Martínez Villalba Ricardo González Cárabes

The study of energy needs in rural areas continues to be an active field of research. Although numerous gaps hinder the achievement of a sustainable energy transition in these areas, it is necessary to develop comprehensive strategies that integrate local participation with the implementation of efficient and appropriate energy technologies. This research analyzes local energy needs using a community participatory approach and considers four main stages, including a participatory diagnosis at the community level to identify energy needs, defining priority energy needs from the community’s viewpoint, estimating a baseline of the identified needs, their economic costs, and environmental impacts, constructing a scenario with a 20-year projection, and the benefits of implementing more efficient technologies. The results show that 98.9% of energy is destined for residential needs, 0.6% for community needs, and 0.5% for productive needs, and the economic expenditure follows the same hierarchy, while total emissions are estimated annually at just over 30,000 tCO2e and 3 tPM2.5. With the proposed scenario, at the end of year 20, a reduction in consumption of just over 200 TJ is estimated, together with present value savings of USD 490,000, and a decrease in emissions of approximately 27,000 tCO2e and 2.7 tPM2.5. This proposal is expected to contribute to encouraging research with broad community participation and to the formulation of strategies that enable a sustainable energy transition in rural contexts.

Resources doi: 10.3390/resources15010015

Authors: Pablo Fernández-Arias Antonio del Bosque Georgios Lampropoulos Diego Vergara

Green hydrogen has become a fundamental pillar in the transition towards a low-carbon economy, due to its ability to produce energy without polluting emissions and from renewable sources such as solar and wind. Unlike other hydrogen production technologies, green hydrogen is obtained through water electrolysis using renewable electricity, which makes it a clean and sustainable fuel, ideal for hard-to-decarbonized sectors such as heavy industry and long-distance transportation. The main objective of this review is to analyze the evolution, trends, and knowledge gaps related to the sustainability of green hydrogen, identifying the main research focus areas, scientific actors, and emerging opportunities. To do this, 1935 scientific articles indexed in Scopus and WOS were examined under PRISMA 2020. Among the most relevant results, an exponential growth in scientific production on hydrogen and sustainability is observed, with Asian authors leading due to strong national commitments. The main challenges identified by the scientific community are related to efficiency, profitability, optimization, integration into sustainable energy systems, and emission reduction. Green hydrogen technologies are central to future energy, and success depends on international collaboration, innovation, and stable policies that support large-scale, sustainable clean energy adoption.

Resources doi: 10.3390/resources15010014

Authors: Sonaly Bhatnagar Rashmi Chaudhary Yasmin Janjhua Akhil Kashyap Pankaj Thakur Prashant Sharma

Climate change brings considerable danger to India’s economic progress, with the agricultural sector and farmers’ livelihoods being particularly vulnerable. Himachal Pradesh is especially susceptible owing to its reliance on climate-sensitive economic activities and limited capacity to adapt to climate variability. Strengthening adaptation strategies in Himachal Pradesh is crucial for fortifying the resilience of communities reliant on environmental resources for their sustenance and economic well-being. This study examines the extent of adoption of Climate-Smart Agricultural Practices (CSAPs), identifies the factors influencing their uptake, and assesses their impact on the livelihood vulnerability of farm households in the temperate region of Himachal Pradesh. Using a multistage random sampling framework, data were collected from 432 farm households through primary surveys and secondary sources. The analysis employs descriptive statistics, a composite livelihood vulnerability index, and Ordinal Logistic and Multiple Linear Regression models. Results show higher adoption of low-cost practices such as composting, fruit-based agroforestry, crop–livestock integration, and mulching, while capital-intensive practices like micro-irrigation were limited due to financial constraints. Adoption is positively influenced by education, extension access, farming experience, financial resources, and climate information exposure. Importantly, CSAPs adoption is found to significantly reduce livelihood vulnerability, indicating enhanced resilience and reduced exposure to climate-induced risks among farm households. The findings highlight climate-smart agriculture as an effective adaptation strategy and underscore the need for policies that strengthen extension services, improve access to credit, and promote affordable climate-smart technologies to enhance resilience in vulnerable hill regions.

Resources doi: 10.3390/resources15010013

Authors: Julio Wasserman Tácila Freitas

The management of landfill leachate remains a persistent environmental issue for municipalities globally. Although dedicated treatment in engineered landfills mitigates environmental contamination, it is often cost-prohibitive. Co-treatment of landfill leachates in sewage treatment plants has been broadly studied, but there are a lot of issues associated with it. Sewage treatment plants apply physical, chemical, and biological processes, and the co-treatment of leachates—contaminated with metals, pesticides, emerging contaminants, and other toxic compounds—can impair the biological equilibrium of the system and compromise the quality of effluents and sludges. In the present research, the processes leading to the formation of landfill leachates and the processes that promote the removal of contaminants in sewage treatment plants were discussed. A theoretical, early screening level mixing model, incorporating removal rates and leachate concentrations from the literature, was employed to simulate effluent concentrations from a co-treatment process involving sequential decantation and an upflow anaerobic sludge blanket (UASB). Under a conservative worst-case scenario obtained from the literature, the model predicts that adsorption of contaminants onto the particulate phase enables removal of metals from the solution. However, considering the volumes of sludge involved, the predictions indicate that concentrations should be lower than naturally occurring in the sediments. It is proposed that continuous monitoring follow-up is a mandatory safeguard for any co-treatment operation.

Resources doi: 10.3390/resources15010012

Authors: Amir Noviyanto Fadhlullah Ramadhani Valensi Kautsar Yovi Avianto Sri Gunawan Yohana Theresia Maria Astuti Siti Maimunah

Reliable estimation of oil palm carbon stock is essential for climate mitigation, concession management, and sustainability certification. While satellite-based approaches offer scalable solutions, redundancy among spectral indices and inter-sensor variability complicate model development. This study evaluates machine learning regressors for predicting oil palm carbon stock at tree (CO_tree, kg C tree−1) and hectare (CO_ha, Mg C ha−1) scales using spectral indices derived from Landsat-8, Landsat-9, and Sentinel-2. Fourteen vegetation indices were screened for multicollinearity, resulting in a lean feature set dominated by NDMI, EVI, MSI, NDWI, and sensor-specific indices such as NBR2 and ARVI. Ten regression algorithms were benchmarked through cross-validation. Ensemble models, particularly Random Forest, Gradient Boosting, and XGBoost, outperformed linear and kernel methods, achieving R2 values of 0.86–0.88 and RMSE of 59–64 kg tree−1 or 8–9 Mg ha−1. Feature importance analysis consistently identified NDMI as the strongest predictor of standing carbon. Spatial predictions showed stable carbon patterns across sensors, with CO_tree ranging from 200–500 kg C tree−1 and CO_ha from 20–70 Mg C ha−1, consistent with published values for mature plantations. The study demonstrates that ensemble learning with sensor-specific index sets provides accurate, dual-scale carbon monitoring for oil palm. Limitations include geographic scope, dependence on allometric equations, and omission of belowground carbon. Future work should integrate age dynamics, multi-year composites, and deep learning approaches for operational carbon accounting.

Resources doi: 10.3390/resources15010011

Authors: Nesrine Gafsi

Using the Autoregressive Distributed Lag (ARDL) model cointegration framework, this paper examines the long- and short-run impact of domestic financial investment and natural resource rents on economic growth in Niger within the period 1990–2021. The Bounds test confirms a long-run relationship among variables: F = 4.646 > 3.79 at 5%. Long-run results indicate that increasing domestic investment by 1% raises real Gross Domestic Product (GDP) per capita by approximately 0.30%, whereas 1% increase in natural resource rents leads to a reduction in growth by approximately 0.06%. At the same time, exports have a positive but very small effect, while imports and labor have negative long-run influences. Short-run dynamics further support a significant positive impact of domestic investment, at p = 0.0007, and a lagged effect of natural resources at p = 0.0308. The error-correction term is negative and significant, at −0.75, showing rapid adjustment toward equilibrium. Diagnostic tests confirm an absence of serial correlation and heteroskedasticity, while stability is confirmed by CUSUM and CUSUMSQ tests. The findings reveal a dualism in the growth path of Niger in that domestic financial investments favor sustainable expansion, whereas resource-based revenues undermine the growth process in the long run and call for financial market deepening and improved governance of resource revenues.

Resources doi: 10.3390/resources15010010

Authors: Agnieszka Pusz Dominik Rogalski Arkadiusz Kamiński Peter Knosala Magdalena Wiśniewska

This study investigates the accumulation potential of Brassica napus L. and Zea mays L. cultivated on soils contaminated with Zn, Cd, Cu and Pb, using HEDTA—Hydroxyethyl Ethylenediamine Triacetic Acid—to enhance metal mobility. The research addresses a gap in the literature regarding the dual-purpose use of energy crops for assisted phytoextraction and bioenergy recovery. Two pot experiments were conducted on soils of different textures, with HEDTA applied at 2.5 and 5 mmol·kg−1. Metal concentrations in soil and plant tissues were measured, and indices such as the geoaccumulation index (Igeo), bioconcentration factors (BCF), translocation factor (TF), metal tolerance index (MTI), crop growth rate (CGR) and higher heating value (HHV) were calculated. Results showed that HEDTA significantly increased Cd and Zn mobility, leading to higher accumulation in rapeseed shoots. Maize demonstrated phytostabilization by retaining metals in roots. Rapeseed biomass exhibited a higher HHV (up to 20.6 MJ·kg−1) and greater carbon and hydrogen content, indicating suitability for thermochemical conversion. Maize, with lower ash content, showed potential for bioethanol production. The findings support the integration of chelate-assisted phytoextraction with energy recovery from biomass.

Resources doi: 10.3390/resources15010009

Authors: Astou Sarr Mamadou Dramé Serigne Niang Abdoulkader Idriss Haitham Ramadan Ali Younous Kharouna Talla John Bagarino Marissa Jasper Ismaila Diallo

This study presents the first comprehensive techno-economic assessment of wind-based green hydrogen production across Senegal, a country highly dependent on fossil fuel imports. Using a novel integrated approach combining 30 years of ERA5 reanalysis data (1993–2023), turbine performance modeling and electrolyzer comparison, it fills an important gap for renewable hydrogen development in West Africa. Wind resources were analyzed at multiple altitudes, revealing strong potential in both coastal and northeastern regions, particularly during the dry season, with higher wind speeds at higher turbine heights. Four turbines (Vestas_150, Goldwind_155, Vestas_126 and Nordex_N100) and two electrolyzer types (alkaline and PEM) were evaluated. The alkaline system performed best. Vestas_150 and Goldwind_155 achieved the highest hydrogen yields of 241 and 183 tons/year and CO2 reductions of 2951 and 2241 tons/year, generating carbon credits of 0.118 M$ and 0.089 M$, respectively. Their levelized cost of electricity remained low (0.042 and 0.039 $/kWh), while smaller turbines showed higher costs. Vestas_150 also had the shortest payback period of 2.16 years, making it the most competitive option. Sensitivity analyses showed that longer system lifespans and high-performance turbines significantly reduce the levelized cost of hydrogen. Priority investment zones include Saint-Louis, Matam, Louga and Tambacounda, with levelized cost of hydrogen values as low as 3.4 $/kg.

Resources doi: 10.3390/resources15010008

Authors: Giulia Castanho Kiril Bahcevandziev Leonel Pereira Olga Filipe João Cotas

Salicornia spp. is a halophytic plant with great potential in sustainable agriculture due to its ability to thrive in saline environments where conventional crops cannot grow. This study investigated Salicornia ramosissima J. Woods cultivated under two systems: hydroponics and substrate environments. The plants produced were subsequently preserved for food applications and chemically characterized within biorefinery processes. Analyses were performed using Fourier Transform Infrared Spectroscopy with Attenuated Total Reflection (FTIR-ATR), Ultraviolet/Visible Spectrophotometry, and Thin-Layer Chromatography (TLC). The hydroponic system proved to be the most promising cultivation method, promoting superior aerial growth ranging from 14% to 50% higher than substrate-grown plants throughout the cultivation period and achieving a higher biomass yield. Regarding pigment preservation, freezing best maintained compound integrity, as observed through TLC analysis, while desiccator and vacuum storage at room temperature were most suitable for hydroponically grown samples. Under vacuum storage, pigments pheophytin A and B and chlorophyll A showed an estimated 33% higher retention compared with desiccator storage. Both cultivation methods demonstrated potential for large-scale applications, highlighting Salicornia ramosissima J. Woods as a valuable crop for saline agriculture and sustainable food production.