Search Results (4,269)

Second-, third-, and fourth-generation biofuels represent an important response to the challenges of clean energy supply and climate change. In this context, the Horizon 2020 “TO-SYN-FUEL” project aimed to produce advanced biofuels together with phosphorus from municipal wastewater sludge through a combination of technologies including a Thermo-Catalytic Reforming system, Pressure Swing Adsorption for hydrogen separation, Hydrodeoxygenation, and biochar gasification for phosphorous recovery. This article presents the environmental performance results of the demonstrator installed in Hohenberg (Germany), with a capacity of 500 kg per hour of dried sewage sludge. In addition, four alternative scenarios are assessed, differing in the source of additional thermal energy used for sludge drying: natural gas, biogas, heat pump, and a hybrid solar greenhouse. The environmental performance of these scenarios is then compared with that of conventional fuel. The comparative study of these scenarios demonstrates that the biofuel obtained through wood gasification complies with the Renewable Energy Directive, while natural gas remains the least sustainable option. Heat pumps, biogas, and greenhouse drying emerge as promising alternatives to align biofuel production with EU sustainability targets. Phosphorus recovery from sewage sludge ash proves essential for compliance, offering clear environmental benefits. Although sewage sludge is challenging due to its high water content, it represents a valuable feedstock whose sustainable management can enhance both energy recovery and nutrient recycling. Full article

Recently, researchers have been focused on the recycling as well as transforming of bio-waste streams into a valuable resource. Banana peels are promising for such application, due to their wide availability. In this context, the integration of banana peel-derived biochar with environmentally benign magnetite has significantly broadened its potential applications as a solar photocatalyst compared to the conventional photocatalysts. The materials are mixed in varied proportions of Ban-Char500-Mag@-(0:1), Ban-Char500@Mag-(1:1) and Ban-Char500@Mag-(2:1) and characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) augmented with dispersive X-ray spectroscopy (EDX). Such modification is leading to an improvement in its application as a solar photocatalyst using the photochemical solar collector facility. The study discusses the factors controlling acetaminophen removal from aqueous effluent within 30 min of solar illumination time. Furthermore, the highlighted optimum parameters are pH 3.0, using 10 mg/L of the Ban-Char500@Mag-(1:1) catalyst and 100 mg/L of the hydrogen peroxide as a Fenton combination system for removing a complete acetaminophen from wastewater (100% oxidation). Also, the temperature influence in the oxidation system is studied and the high temperature is unfavorable, which verifies that the reaction is exothermic in nature. The catalyst is signified as a sustainable (recoverable, recyclable and reusable) substance, and showed a 72% removal even though it was in the six cyclic uses. Further, the kinetic study is assessed, and the experimental results revealed the oxidation process is following the first-order kinetic reaction. Also, the kinetic–thermodynamic parameters of activation are investigated and it is confirmed that the oxidation is exothermic and non-spontaneous in nature. Full article

Biofuels represent a sustainable alternative that supports global energy development without compromising environmental balance. This work introduces a novel hardware–software platform for the experimental characterization of biomass solid yield during the slow pyrolysis process, integrating physical experimentation with advanced computational modeling. The hardware consists of a custom-designed pyrolizer equipped with temperature and weight sensors, a dedicated control unit, and a user-friendly interface. On the software side, a two-step kinetic model was implemented and coupled with three optimization algorithms, i.e., Particle Swarm Optimization (PSO), Genetic Algorithm (GA), and Nelder–Mead (N-M), to estimate the Arrhenius kinetic parameters governing biomass degradation. Slow pyrolysis experiments were performed on wheat straw (WS), pruning waste (PW), and biosolids (BS) at a heating rate of 20 °C/min within 250–500 °C, with a 120 min residence time favoring biochar production. The comparative analysis shows that the N-M method achieved the highest accuracy (100% fit in estimating solid yield), with a convergence time of 4.282 min, while GA converged faster (1.675 min), with a fit of 99.972%, and PSO had the slowest convergence time at 6.409 min and a fit of 99.943%. These results highlight both the versatility of the system and the potential of optimization techniques to provide accurate predictive models of biomass decomposition as a function of time and temperature. Overall, the main contributions of this work are the development of a low-cost, custom MATLAB-based experimental platform and the tailored implementation of optimization algorithms for kinetic parameter estimation across different biomasses, together providing a robust framework for biomass pyrolysis characterization. Full article

Soil amendments can enhance soil and plant health; however, limited research has addressed their effects on soil health and crop productivity in alkaline soil. This study investigated the effects of various soil amendments and biostimulants by the Haney Soil Health Test, plant sap analysis, and Cucurbita pepo cv. ‘Dunja’ yield and quality. Treatments included unamended soil (T1) and applications of Humisoil® (T2), Humisoil with biochar (T3), wood vinegar (T4), Ensoil algae^TM (T5), and Humisoil with biochar and basaltic rock dust (T6). Compared to T1, T6, T5, T2, and T3 increased yield by 107%, 87%, 86%, and 52%, respectively. Regarding total fruit number per plant, T2, T6, and T5 outperformed T1 by 42%, 37%, and 37%, respectively. Additionally, T6 decreased Na concentration by 59% in the sap of young leaves and 50% in old leaves compared to T1. Compared to T1, T2 also reduced Na concentration in the sap of old leaves by 63%. For Cl, decreases of 30%, 16%, and 24% in old leaves were observed in T2, T4, and T6 treatments, respectively. These findings highlight the potential of biostimulants and soil amendments to improve zucchini yield and quality while improving soil health in alkaline soils. Full article

This study evaluated the impact of biochar on the growth of strawberry plants, combining visual and proximal sensing monitoring. The plants were rooted in soil enriched with biochar, derived from pyrolysis of soft wood at 550 °C and applied in two doses (2 and 15 g/L), and after physical activation with CO₂ at 900 °C; there was also a treatment with no biochar (unaltered). Visual monitoring was based on data logging twice per week of plants’ height and number of flowers and ripe fruits. Proximal sensing monitoring involved a system including a low-cost multispectral camera and a Raspberry Pi 4. The camera acquired nadiral images hourly in three spectral bands (550, 660, and 850 nm), allowing calculation of the normalized difference vegetation index (NDVI). After three months, control plants reached a height of 12.3 ± 0.4 cm, while those treated with biochar and activated biochar grew to 18.03 ± 1.0 cm and 17.93 ± 1.2 cm, respectively. NDVI values were 0.15 ± 0.11 for control plants, increasing to 0.26 ± 0.03 (+78%) with biochar and to 0.28 ± 0.03 (+90%) with activated biochar. In conclusion, biochar application was beneficial for strawberry plants’ growth according to both visual and proximal-sensed measures. Further research is needed to optimize the integration of visual and proximal sensing monitoring, also enhancing the measured parameters. Full article

This study presents the preparation of iron and nitrogen co-doped sludge-based biochar (FeCN-MSBC) and iron oxide-doped biochar (FeO-MSBC) by ball milling municipal sludge with different iron precursors (K₃Fe(CN)₆ and Fe₂O₃), followed by pyrolysis. These biochars were utilized to activate persulfate (PMS) for the degradation of phenolic pollutants. The results demonstrate that FeCN-MSBC, formed by the introduction of K₃Fe(CN)₆, contains Fe/N phases, with surface Fe sites exhibiting a lower oxidation state, which significantly enhances PMS activation efficiency. In contrast, FeO-MSBC, due to the aggregation of Fe₂O₃/Fe₃O₄, shows relatively lower catalytic activity. The FeCN-MSBC/PMS system degrades pollutants via a synergistic mechanism involving non-radical pathways mediated by ¹O₂ and electron transfer processes (ETP) catalyzed by surface Fe. Electrochemical oxidation and quenching experiments confirm that ETP is the dominant pathway. FeCN-MSBC, prepared at a pyrolysis temperature of 600 °C and an Fe loading of 3 mmol/g TSS, exhibited the best performance, achieving a phenol degradation rate constant (k_obs) of 0.127 min⁻¹, 4.5 times higher than that of undoped biochar (MSBC). FeCN-MSBC/PMS maintained high efficiency across a wide pH range and in complex water matrices, exhibiting excellent stability over multiple cycles, demonstrating strong potential for practical applications. This study provides an effective strategy for simultaneous Fe and N doping in sludge-derived biochar and offers mechanistic insights into Fe/N synergistic activation of PMS for practical water treatment. Full article

Advanced oxidation processes (AOPs) utilizing peroxymonosulfate (PMS) have recently gained attention for effectively removing organic dyes. Biochar, a carbon-based material, can act as a catalyst carrier for PMS activation. This study developed a nitrogen-doped biochar catalyst (NCMR800–2) from waste Chinese medicine residue (CMR) through one-step pyrolysis to efficiently remove Rhodamine B (RhB) from wastewater. Results indicate that NCMR800–2 rapidly achieved complete removal of 20 mg/L Rhodamine B (RhB), the primary focus of this study, within 30 min, while maintaining high degradation efficiencies for other pollutants and significantly outperforming the unmodified material. The material demonstrates strong resistance to ionic interference and operates effectively across a wide pH range. Quenching experiments and in situ testing identified singlet oxygen (¹O₂) as the primary active species in RhB degradation. Electrochemical analysis showed that nitrogen doping significantly enhanced the electrical conductivity and electron transfer efficiency of the catalyst, facilitating PMS decomposition and RhB degradation. Liquid chromatography–mass spectrometry (LC-MS) identified intermediate products in the RhB degradation process. Seed germination experiments and TEST toxicity software confirmed a significant reduction in the toxicity of degradation products. In conclusion, this study presents a cost-effective, efficient catalyst with promising applications for removing persistent organic dyes. Full article

The REPowerEU plan is aimed at a target of 35 bcm of biomethane annually by 2030, up from 4 bcm in 2023, requiring about EUR 37 billion in investment. Food waste is identified as a key feedstock, characterized by discrete homogeneity, although its availability may vary seasonally. In Italy, the Emilia-Romagna region generates approximately 450 kt/y of industrial waste from the food and beverage sector, primarily originating from meat processing (NACE 10.1), fruit and vegetable processing (NACE 10.3), and the manufacture of vegetable and animal oils and fats (NACE 10.4). Of this amount, food and beverage processing waste (EWC 02) accounts for about 302 kt from NACE 10 (food, year 2019) and 14 kt from NACE 11 (beverage, year 2019). This study provides a comprehensive screening of waste streams generated by the local food and beverage industry in Emilia-Romagna, evaluating the number of enterprises, their value added, and recorded waste production. The screening led to the identification of suitable streams for further valorization strategies: a total of ~93 kt/y was selected for the preliminary conceptual design of an integrated process combining anaerobic digestion with hydrothermal treatment, aimed at supporting national biomethane production targets while maximizing material recovery through hydrochar production. Preliminary estimations indicate that the proposed process may achieve a biochemical methane potential of approximately 0.23 Nm³/kg_VS, along with a hydrochar yield of about 130 kg/t_waste. Full article

The applicability of biochar as a coarse aggregate substitute in concrete to increase sustainability and multifunctionality was investigated. Biochar, a porous carbon-rich byproduct from biomass pyrolysis, was incorporated at various replacement ratios (5–20%) under four water-to-binder (w/b) conditions (0.25–0.40). The key physical, mechanical, thermal, and microstructural properties, including the unit weight, porosity, compressive strength, flexural strength, and thermal conductivity, were evaluated via SEM and EDS analyses. The results revealed that although increasing the biochar content reduced the mechanical strength, it significantly improved the thermal insulation performance because of the porous structure of the biochar. At low w/b ratios and 5–10% biochar content, sufficient mechanical properties were retained, indicating a viable design range. Higher replacement ratios (>15%) led to excessive porosity, reduced hydration, and impaired durability. This study quantitatively analyzed the interproperty correlations, confirming that the strength and thermal performance are closely linked to the internal matrix density and porosity. These findings suggest that biochar-based concrete has potential for use in thermal energy storage systems, high-temperature insulation, and low-carbon construction. The low-carbon effect is achieved both by sequestering stable carbon within the concrete matrix and by partially replacing cement, thereby reducing CO₂ emissions from cement production. Moreover, the results highlight a strong correlation between increased porosity, enhanced thermal insulation, and reduced strength, thereby offering a solid foundation for sustainable material design. In particular, the term ‘high temperature’ in this context refers to exposure conditions above approximately 200~400 °C, as reported in previous studies. However, this should be considered as a potential application to be validated in future experiments rather than a confirmed outcome of this study. Full article

Bamboo (subfamily Bambusoideae, Poaceae) ranks among the fastest-growing plants on Earth, achieving up to 1 m day⁻¹, significantly faster than other fast growing woody plant such as Eucalyptus (up to 0.6 m day⁻¹) and Populus (up to 0.5 m day⁻¹). Native to Asia, South America and Africa, and cultivated on approximately 37 million ha worldwide, bamboo delivers multifaceted environmental, social, and economic benefits. Historically central to construction, handicrafts, paper and cuisine, bamboo has evolved into a high-value cash crop and green innovation platform. Its rapid renewability allows multiple harvests of young shoots in fast-growing species such as Phyllostachys edulis and Dendrocalamus asper. Its high tensile strength, flexibility, and ecological adaptability make it suitable for applications in bioenergy (bioethanol, biogas, biochar), advanced materials (engineered composites, textiles, activated carbon), and biotechnology (fermentable sugars, prebiotics, biochemicals). Bamboo shoots and leaves provide essential nutrients, antioxidants and bioactive compounds with documented health and pharmaceutical potential. With a global market value exceeding USD 41 billion, bamboo demand continues to grow in response to the call for sustainable materials. Ecologically, bamboo sequesters up to 259 t C ha⁻¹, stabilizes soil, enhances agroforestry systems and enables phytoremediation of degraded lands. Nonetheless, challenges persist, including species- and age-dependent mechanical variability; vulnerability to decay and pests; flammability; lack of standardized harvesting and engineering codes; and environmental impacts of certain processing methods. This review traces bamboo’s trajectory from a traditional resource to a strategic bioresource aligned with Industry 5.0, underscores its role in low-emission, circular bioeconomies and identifies pathways for optimized cultivation, green processing technologies and integration into carbon-credit frameworks. By addressing these challenges through innovation and policy support, bamboo can underpin resilient, human-centric economies and drive sustainable development. Full article

Fruit production is a high environmental impact sector, requiring sustainable strategies that reduce greenhouse gas (GHG) emissions, improve resource efficiency, and maintain fruit quality. This study assessed the environmental performance of innovative substrates with biodegradable additives and organic binders in tunnel-grown raspberry production. The functional unit was 1 kg of marketable fruit, and the experiment was conducted in Karwia, Poland. GHG emissions were calculated for eight substrate variants following ISO 14040 and 14041 guidelines. The baseline was coconut fiber, while modified variants included the additions of sunflower husk biochar and/or a wood-industry isolate, representing sustainable strategies in soilless cultivation. Emissions ranged from 0.728 to 1.226 kg CO₂ eq/kg of raspberries, with the control showing the highest values. All modified substrates (produced based on a mixture of biochar and isolate) reduced emissions, with the most efficient variant achieving nearly a 40% decrease. Water use efficiency was decisive, as consumption declined from 2744 m³/ha (control) to 1838 m³/ha in improved variants. Substrate air–water properties proved critical for both environmental and economic outcomes. The findings confirm that substrate modification constitutes an effective, sustainable strategy for raspberry production under high tunnels, supporting climate-smart horticulture and resource-efficient food systems. Full article

This study systematically explores the mechanisms and application potential of biochar in remediating heavy metal-contaminated soils. Particular emphasis is placed on the role of raw materials and pyrolysis conditions in modulating key physicochemical properties of biochar, including its aromatic structure, porosity, cation exchange capacity, and ash content, which collectively enhance heavy metal immobilization. The direct remediation mechanisms are categorized into six pathways: physical adsorption, electrostatic interactions, precipitation, ion exchange, organic functional group complexation, and redox reactions, with particular emphasis on the reduction in toxic Cr⁶⁺ and the oxidation of mobile As³⁺. In addition to direct interactions, biochar indirectly facilitates remediation by enhancing soil carbon sequestration, improving soil physicochemical characteristics, stimulating microbial activity, and promoting plant growth, thereby generating synergistic effects. The study evaluates combined remediation strategies integrating biochar with phytoremediation and microbial remediation, highlighting their enhanced efficiency. Moreover, practical challenges related to the long-term stability, ecological risks, and economic feasibility in field applications are critically analyzed. By synthesizing recent theoretical advancements and practical findings, this research provides a scientific foundation for optimizing biochar-based soil remediation technologies. Full article

This study investigated the efficacy of agave bagasse biochar and zeolite as filter materials for the removal of boron from water using a continuous flow column system. Experiments were conducted with varying initial boron concentrations and contact times. The results showed moderate boron removal capabilities, with agave biochar slightly outperforming zeolite. Maximum removal percentages of 29.31% for zeolite and 33.12% for agave biochar were achieved at the lowest initial boron concentration. Factorial analysis revealed significant effects of concentration, contact time, and column material on boron removal, with contact time having the largest impact. The interaction between concentration and column material suggests the potential for optimization. While removal percentages were lower compared to some chemically modified materials, the use of low-cost, natural filter media offers sustainability advantages. These materials show promise for treating water with lower boron levels or as part of a multi-step treatment process. Future research should focus on optimizing experimental conditions and exploring material modifications to enhance boron removal efficiency. Full article

In the circular economy framework, municipal wastes are seen as secondary raw materials that can be used to fertilize agricultural soils. This study assessed the effect of different biowaste and green waste treatment schemes on P fertilizer value to learn about the optimal valorization of these feedstocks. The wastes were used either fresh, after composting or anaerobic digestion, or as biochars produced at various pyrolysis conditions. The fertilizer value was determined from the change in soil concentration of plant-available P (P_CAL) in incubation experiments with different soils and the temporal dynamics of fertilizer-induced growth and P accumulation of ryegrass in a pot experiment with eight harvests. The mode of waste treatment significantly influenced the P fertilizer value in the incubation and in the pot experiment. In the incubation experiment, the amendment-induced P_CAL increase varied between 22% and 33% of applied P on low-P acidic soil and between 55% and 88% of applied P on high-P acidic soil, whereby the amendment effects were mainly determined by their effects on soil pH. In the pot experiment with low-P acidic soil, the apparent P recovery in the plant biomass (APR) varied between 2% of applied P for fresh green waste and 42% for fluid digestate. The amendment effects on APR were not related to soil pH but to the P_CAL supply with the amendments and amendment effects on soil P supply. Our data show great potential for increasing the P fertilizer value of organic municipal waste materials through appropriate processing prior to application. Full article

The activation of persulfate (PS) to oxidize and degrade 2,4-dichlorophenol (2,4-DCP) in aqueous solution represents a prevalent advanced oxidation technology. This study established a PS activation system using sulfide-modified nanoscale zero-valent iron supported on biochar (S-nZVI@BC). The optimal conditions included a PS:2,4-DCP mass ratio of 70:1 and S-nZVI@BC:PS of 1.5:1. The activator had excellent stability after being reused five times, which lead to high cost-effectiveness and sustainable usability. This system exhibited broad pH adaptability (3–11), with enhanced efficiency under acidic/neutral conditions. Chloride ion, nitrate, and carbonate had effects during the degradation. During the initial degradation phase, S-nZVI@BC played a primary role, with a greater contribution rate of adsorption than reduction. Fe⁰ played a dominant role in the PS activation process; reactive species—including HO•, SO₄•⁻, and O₂•⁻—were identified as key agents in subsequent degradation stages. The overall degradation processes comprised three distinct stages: dechlorination, ring-opening, and mineralization. Full article