Search Results (180)

To evaluate water pollution status and sustainable development potential in the Huai River Basin, this study focused on the spatiotemporal evolution and influencing factors of the grey water footprint (GWF) across 35 cities in the basin from 2005 to 2020. This study quantifies the GWF from agricultural, industrial, and domestic perspectives and analyzes its spatial disparities by incorporating spatial autocorrelation analysis. The Tapio decoupling model was applied to explore the relationship between pollution and economic growth, and geographic detectors along with the STIRPAT model were utilized to identify driving factors. The results revealed no significant global spatial clustering of GWF in the basin, but a pattern of “high in the east and west, low in the north and south” emerged, with high-value areas concentrated in southern Henan and northern Jiangsu. By 2020, 85.7% of cities achieved strong decoupling, indicating improved coordination between the environment and economy. Key driving factors included primary industry output, crop sown area, and grey water footprint intensity, with a notable interaction between agricultural output and grey water footprint intensity. The quantitative analysis based on the STIRPAT model demonstrated that seven factors, including grey water footprint intensity and total crop sown area, exhibited significant contributions to influencing variations. Ranked by importance, these factors were grey water footprint intensity > total crop sown area > urbanization rate > population size > secondary industry output > primary industry output > industrial wastewater discharge, collectively explaining 90.2% of the variability in GWF. The study provides a robust scientific basis for water pollution control and differentiated management in the river basin and holds significant importance for promoting sustainable development of the basin. Full article

Societies are aiming to have a higher ecological consciousness in wastewater treatment operations and achieve a more sustainable future. With this said, global demands for larger quantities of resources and the consequent waste generated will inevitably lead to the exhaustion of current municipal wastewater treatment works. The utilization of biosolids (particularly microbial proteins) from wastewater treatment operations could generate a sustainable bio-adhesive for the wood industry, reduce carbon footprint, mitigate health concerns related to the use of carcinogenic components, and support a more circular economic option for wastewater treatment. A techno-economic analysis for three 10 MGD wastewater treatment operations producing roughly 11,300 dry pounds of biosolids per day, in conjunction with co-feedstock defatted soy flour protein at varying ratios (i.e., 0%, 15%, and 50% wet weight), was conducted. Aspen Capital Cost Estimator V12 was used to design and estimate installed equipment additions for wastewater treatment plant integration into an urban biorefinery process. Due to the mechanical attributes and market competition, the chosen selling prices of each adhesive per pound were set for analysis as USD 0.75 for Plant Option P1, USD 0.85 for Plant Option P2, and USD 1.00 for Plant Option P3. Over a 20-year life, each plant option demonstrated economic viability with high NPVs of USD 107.9M, USD 178.7M, and USD 502.2M and internal rates of return (IRRs) of 24.0%, 29.0%, and 44.2% respectively. The options examined have low production costs of USD 0.14 and USD 0.19 per pound, minimum selling prices of USD 0.42–USD 0.51 per pound, resulting in between 2- and 4-year payback periods. Sensitivity analysis shows the effects biosolid production fluctuations, raw material market price, and adhesive selling price have on economics. The results proved profitable even with large variations in the feedstock and raw material prices, requiring low market selling prices to reach the hurdle rate of examination. This technology is economically enticing, and the positive environmental impact of waste utilization encourages further development and analysis of the bio-adhesive process. Full article

Wastewater treatment plants (WWTPs) face increasing pressure to handle higher volumes of water due to climate change causing storm surges, which current infrastructure cannot handle. Aerobic granular sludge (AGS) is a promising alternative to activated sludge systems due to their improved settleability property, lowering the land footprint and improving efficiency. This research investigates the optimisation of a lab-scale sequencing batch reactor (SBR) into a continuous flow reactor through mathematical modelling, sensitivity analysis, and a computational fluid dynamic model. This is all applied for the future goal of scaling up the model designed to a full-scale continuous flow reactor. The mathematical model developed analyses microbial kinetics, COD degradation, and mixing flows using Reynolds and Froude numbers. To perform a sensitivity analysis, a Python code was developed to investigate the stability when influent concentrations and flow rates vary. Finally, CFD simulations on ANSYS Fluent evaluated the mixing within the reactor. An 82% COD removal efficiency was derived from the model and validated against the SBR data and other configurations. The sensitivity analysis highlighted the reactor’s inefficiency in handling high-concentration influents and fast flow rates. CFD simulations revealed good mixing within the reactor; however, they did show issues where biomass washout would be highly likely if applied in continuous flow operation. All of these results were taken under deep consideration to provide a new reactor configuration to be studied that may resolve all these downfalls. Full article

In accordance with growing environmental pressures and the demand for sustainable industrial practices, membrane technologies have emerged as key enablers for increasing efficiency, reducing emissions, and supporting circular processes across multiple sectors. This review focuses on the integration among microalgae-based systems, offering innovative and sustainable solutions for biomass production, carbon capture, and industrial wastewater treatment. In cultivation, membrane photobioreactors (MPBRs) have demonstrated biomass productivity up to nine times greater than that of conventional systems and significant reductions in water (above 75%) and energy (approximately 0.75 kWh/m³) footprints. For carbon capture, hollow fiber membranes and hybrid configurations increase CO₂ transfer rates by up to 300%, achieving utilization efficiencies above 85%. Coupling membrane systems with industrial effluents has enabled nutrient removal efficiencies of up to 97% for nitrogen and 93% for phosphorus, contributing to environmental remediation and resource recovery. This review also highlights recent innovations, such as self-forming dynamic membranes, magnetically induced vibration systems, antifouling surface modifications, and advanced control strategies that optimize process performance and energy use. These advancements position membrane-based microalgae systems as promising platforms for carbon-neutral biorefineries and sustainable industrial operations, particularly in the oil and gas, mining, and environmental technology sectors, which are aligned with global climate goals and the UN Sustainable Development Goals (SDGs). Full article

Vertical greening systems (VGSs) serve as an advanced ecological wastewater treatment technology, offering advantages such as a small spatial footprint and increased green space coverage. VGSs have been widely applied to treat various types of wastewaters, including blackwater and greywater. However, a systematic review of the pollutant removal efficiency of VGSs in treating blackwater and greywater, as well as the influencing factors, remains lacking. This study compiles data on the removal efficiencies of chemical oxygen demand (COD), total phosphorus (TP), total nitrogen (TN), and ammonium nitrogen (NH₄⁺-N) from greywater and blackwater using VGSs. Additionally, the effects of the hydraulic loading rate, substrate type, and the number of system layers on pollutant removal performance are assessed. When treating blackwater, the pollutant removal efficiency showed a positive correlation with hydraulic loading within the range of 85 L × (m² × d)⁻¹ to 200 L × (m² × d)⁻¹; substrates such as zeolite or vermiculite exhibited superior removal performance, and increasing the number of system layers enhanced the pollutant removal efficiency. When treating greywater, the hydraulic loading rate and system layers have limited influence on COD and TN removal, while excessive hydraulic loading or system layers may negatively affect TP removal. Substrate mixtures composed of perlite and coconut coir achieved a higher pollutant removal efficiency. In conclusion, optimizing key parameters such as the hydraulic loading rate, substrate composition, and the number of system layers can significantly enhance the pollutant removal efficiency of VGSs. Full article

Olive oil and its derivatives, particularly polyphenol-rich extracts, are valued for their antioxidant, anti-inflammatory, and regenerative properties. Olive mill wastewater (OMWW), a byproduct of olive oil production, traditionally seen as an environmental pollutant, has emerged as a promising source of high-value dermatological ingredients. Key polyphenols such as hydroxytyrosol, oleuropein, and tyrosol exhibit potent antioxidant, anti-inflammatory, antimicrobial, and photoprotective effects. These compounds mitigate oxidative stress, prevent collagen degradation, modulate NF-κB and MAPK signaling, and promote cellular repair and regeneration. Skin health is increasingly recognized as crucial to overall well-being, driving interest in cosmeceuticals that combine cosmetic benefits with dermatological activity. This review examines the cosmeceutical and dermatological potential of OMWW, highlighting its incorporation into innovative topical formulations like oil-in-water nanoemulsions, liposomes, and microneedles that enhance skin penetration and bioavailability. Additionally, OMWW fractions have shown selective antiproliferative effects on melanoma cells, suggesting potential for skin cancer prevention. Valorization of OMWW through biorefinery processes aligns with circular-economy principles, converting agro-industrial waste into sustainable cosmeceutical ingredients. This approach not only meets consumer demand for natural, effective products, but also reduces the ecological footprint of olive oil production, offering a scalable, eco-friendly strategy for next-generation dermatological applications. Full article

Against the backdrop of China’s “dual carbon” strategy, investigating the carbon emission characteristics and low-carbon operational status of wastewater treatment plants (WWTPs) across regions is pivotal for achieving synergistic pollution reduction and carbon mitigation. Leveraging 2024 operational data from 98 WWTPs in eastern China—encompassing treatment volume, energy consumption, sludge production, and chemical dosages—this study refined the Assessment Standard for Carbon Mitigation in Municipal WWTPs and Technical Specification for Low-Carbon Operation of WWTPs. A novel carbon accounting framework and low-carbon performance evaluation system were subsequently developed to analyze the impacts of treatment scale, technological configuration, and load rate on carbon footprints. Key findings revealed an average carbon intensity of 0.399 kg CO₂-eq/m³ for the region, with small-scale facilities (0.582 kg CO₂-eq/m³) exhibiting significantly higher emissions compared to their large-scale counterparts (0.392 kg CO₂-eq/m³). Indirect emissions constituted 62.1% of the total footprint, while chemical dosing contributed 14.2%, primarily driven by carbon sources and phosphorus removal agents. Fossil-derived CO₂ accounted for 4.6% of emissions. Notably, the AAO process demonstrated the lowest carbon intensity (0.370 kg CO₂-eq/m³), whereas SBR systems registered the highest (0.617 kg CO₂-eq/m³). Furthermore, 25% of the assessed facilities were classified as high-emission plants. Strategic recommendations are proposed, including prioritizing AAO process optimization, implementing intelligent chemical dosing control, utilizing food wastewater as an alternative carbon source, and enhancing operational load rates, to advance synergistic environmental and carbon mitigation goals in eastern China’s wastewater sector. Full article

With growing global concerns over sustainable wastewater treatment, there is a pressing need for low-cost, eco-friendly filtration solutions. This study conducted a life cycle assessment (LCA) to evaluate the potential of improving slow sand filtration efficiency by integrating alternative materials like clay and oyster shell powder (OSP), while minimizing the environmental footprint. Additionally, the adaptability of three-dimensional (3D) printing was explored to incorporate these materials into innovative filter designs, assessing scalability for broader wastewater applications. Ten filter configurations, including a slow sand filter (SSF) enhanced with OSP (90:10) and 3D-printed clay–OSP bricks (ratios of 90:10, 85:15, 80:20), were assessed across three sourcing distances: local (in situ), regional (161 km), and distant (1609 km). The results showed that SSFs with OSP consistently delivered lower environmental impacts, reducing freshwater ecotoxicity, eutrophication, and human toxicity by up to 4% compared to conventional SSFs, particularly when transport was minimized. Among brick-based systems, single-brick columns offered the best balance of performance and impact, while three-brick columns had the highest environmental burden, largely due to the increased electricity use. Economic analysis reinforced the environmental findings: SSFs with OSP were the most cost-effective option, followed closely by SSFs, while brick-based systems were slightly more expensive, with costs rising sharply when sourcing distances exceeded 161 km. Overall, integrating OSP into SSFs offers an optimal balance of sustainability and affordability, while single-brick columns (90:10) present a promising alternative. Future research should further optimize material blends and design configurations to align with long-term environmental and economic goals. Full article

The mounting global population and the challenges posed by climate change underline the need for sustainable food production systems. This review synthesizes evidence for a dual-track bioeconomy, green (terrestrial plants and insects) and blue (aquatic algae), as complementary pathways toward sustainable nutrition. A comprehensive review of the extant literature, technical reports, and policy documents published between 2015 and 2025 was conducted, with a particular focus on environmental, nutritional, and techno-economic metrics. In addition, precision agriculture datasets, gene-editing breakthroughs, and circular biorefinery case studies were extracted and compared. As demonstrated in this study, the use of green resources, such as legumes, oilseeds, and edible insects, results in a significant reduction in greenhouse gas emissions, land use, and water footprints compared with conventional livestock production. In addition, these alternative protein sources offer substantial benefits in terms of bioactive lipids. Blue resources, centered on micro- and macroalgae, furnish additional proteins, long-chain polyunsaturated fatty acids, and antioxidant pigments and sequester carbon on non-arable or wastewater substrates. The transition to bio-based resources is facilitated by technological innovations, such as gene editing and advanced extraction methods, which promote the efficient valorization of agricultural residues. In conclusion, the study strongly suggests that policy support be expedited and that research into bioeconomy technologies be increased to ensure the sustainable meeting of future food demands. Full article

Indonesia plays a dominant role in the global refined palm oil (RPO) supply chain. Given the increasing global emphasis on carbon neutrality and sustainable trade, understanding the carbon footprint of Indonesian RPO and its embodied carbon emissions (ECE) in global trade is essential for identifying mitigation opportunities and aligning with international sustainability standards. This study integrates life cycle assessment and trade data to quantify the carbon footprint of RPO products and analyze the spatiotemporal patterns of trade-related ECE. Results show that producing 1 ton of RPO emits 2196.84 kg CO₂e, with wastewater treatment (57.67%) and land use change (32.82%) as the main contributors. From 2010 to 2022, ECE induced by RPO exports rose from 35.79 Mt CO₂e to 54.94 Mt CO₂e (3.64% annual growth). Major ECE importers were India, China, and Pakistan, accounting for 20.36%, 14.29%, and 11.45% of Indonesia’s total trade-related ECE, respectively. Comprehensive sensitivity and uncertainty analyses conducted on key parameters confirmed the robustness of the above results. Based on these robust findings, integrated mitigation strategies targeting both production optimization and sustainable trade mechanisms are proposed to accelerate Indonesia’s RPO industry decarbonization. Full article

The rapid expansion of shale gas development has revolutionized global energy markets, yet it has also introduced substantial environmental challenges, particularly concerning groundwater resources. This comprehensive review systematically examines the multifaceted impacts of shale gas extraction on groundwater, with a focus on contamination mechanisms, pollutant sources, and mitigation strategies. The study identifies key operational stages—exploration, drilling, hydraulic fracturing, and flowback—as potential sources of groundwater contamination. Inorganic pollutants, including heavy metals and radionuclides, as well as organic compounds such as hydrocarbons and chemical additives, are identified as primary contaminants. The review critically evaluates current wastewater treatment technologies, including reinjection, internal reuse, and advanced desalination methods, highlighting their efficacy and limitations. Additionally, the study proposes a refined environmental management framework that integrates wellbore integrity optimization, enhanced shale gas wastewater treatment, and stringent monitoring protocols. The adoption of clean fracturing technologies and renewable energy applications is recommended to minimize environmental footprints. By establishing comprehensive baseline data and robust pollution monitoring systems, this research provides a scientific foundation for sustainable shale gas development, ensuring the protection of groundwater resources. This review emphasizes the imperative of balancing energy security with environmental sustainability, offering actionable insights for policymakers, industry stakeholders, and environmental scientists. Full article

Modern pig production must balance efficiency, animal welfare, and environmental sustainability while embracing circular bioeconomy principles. This review critically examines the scientific literature from the past decade, focusing on the environmental impacts of pig farming, animal welfare considerations, and circular bioeconomy strategies. Key challenges include the ethical treatment of pigs, regulatory frameworks, and the sector’s contribution to climate change through emissions and resource use. Sustainable pig farming relies on innovative housing systems, welfare-oriented management practices, and legislative measures that improve animal welfare. Moreover, integrating circular bioeconomy strategies, which include manure management for biogas production, alternative feed ingredients, and wastewater recycling, enhances resource efficiency while reducing environmental footprints. Life Cycle Assessment (LCA) methodologies provide insight into the environmental impacts of different production systems, guiding policymakers and producers toward more sustainable practices. Despite these advances, further research is needed to optimize feed alternatives, improve manure treatment technologies, and explain how to improve animal welfare standards. This review highlights the importance of interdisciplinary approaches in achieving sustainable pig farming and underscores the need for continued innovation in aligning productivity and environmental aims. Full article

Wastewater treatment plants (WWTPs) are crucial for environmental protection and public health; however, they are among the most energy-intensive facilities in the water sector. This study examines the correlation between energy consumption and treatment efficiency at the Metamorphosis WWTP (MWWTP) in Attica, Greece, during the years 2022 and 2023. By analyzing influent and effluent characteristics, energy consumption patterns, and the removal efficiencies of key pollutants—Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD₅), and Suspended Solids (SS)—this research provides valuable insights into optimizing wastewater treatment operations. The findings reveal that, despite seasonal variations and fluctuations in influent composition, the facility consistently achieved high pollutant removal rates while maintaining stable energy consumption. The influent BOD₅ increased from 992.8 mg L⁻¹ in 2022 to 1122.3 mg L⁻¹ in 2023. COD rose from 1925.4 mg L⁻¹ to 2594.4 mg L⁻¹, SS from 1280.8 mg L⁻¹ to 1421.2 mg L⁻¹, and total phosphorus from 14.2 mg L⁻¹ to 17.0 mg L⁻¹. Effluent concentrations remained consistently low, with BOD₅ at 6.1 mg L⁻¹ in 2022 and 4.7 mg L⁻¹ in 2023; COD at 23.8 mg L⁻¹ and 25.2 mg L⁻¹, respectively; total nitrogen at 20.2 mg L⁻¹ and 16.7 mg L⁻¹; total phosphorus at 2.4 mg L⁻¹ and 2.6 mg L⁻¹; and SS at 2.4 mg L⁻¹ and 3.5 mg L⁻¹. These results indicate removal efficiencies exceeding 90%. Energy consumption remained stable, recorded at 13,044.9 kWh (0.593 kWh m⁻³ influent) in 2022 and 13,126.1 kWh (0.598 kWh m⁻³ influent) in 2023. These results highlight the importance of integrating energy-efficient strategies and renewable energy solutions to enhance wastewater treatment plant (WWTP) sustainability. This study contributes to ongoing efforts to improve energy optimization in wastewater treatment, supporting global initiatives for carbon footprint reduction and advancing the principles of a circular economy. Full article

Anaerobic digestion (AD) offers a sustainable solution by treating biodegradable waste while recovering bioenergy, enhancing the share of renewable energy. Thus, this study aims to investigate the AD for managing and valorizing residues from the potato chip industry: potato peel (PP), potato offcuts (OC), waste cooking oil (WCO), wastewater (WW), and sewage sludge (SS). In particular, the biochemical methane potential (BMP) of each residue, anaerobic co-digestion (AcoD), and greenhouse gas (GHG) emissions of an AD plant are assessed. WW, OC, and SS present a BMP of around 232–280 NmL_CH4/kg of volatile solids (VS). PP and WCO reach a BMP slightly lower than the former substrates (174–202 NmL_CH4/g_VS). AcoD results in methane yields between 150 and 250 NmL_CH4/g_VS. An up-scaled anaerobic digester is designed to manage 1.60 Mg/d of PP. A residence time of 12 days and a digester with 165 m³ is estimated, yielding 14 Nm³_CH4/Mg_VS/d. A simulated AD plant integrated with a combined heat and power unit results in a carbon footprint of 542 kg of CO₂-eq/Mg_db PP, primarily from biogenic GHG emissions. These findings highlight the potential of AD to generate renewable energy from potato industry residues while reducing fossil fuel-related GHG emissions and promoting resource circularity. Full article

This study examined the carbon footprints of freshwater fish farming and Euryale ferox seed (gorgon fruit) production, comparing integrated ecological mode and traditional farming practices based on ISO 14067 and PAS 2050 standards. The ecological mode achieved a 24% lower carbon footprint per unit product than traditional practices, driven by reduced material and energy use. Key emission sources included aeration electricity, feed, and wastewater treatment for fish farming, fertilizers, insecticides, and drainage energy for E. ferox planting. The integrated model combining high-density fish ponds and E. ferox pond reduced the overall carbon footprint (Micropterus salmoides: 4.342 kg CO₂-eq/kg; E. ferox seed: 0.208 kg CO₂-eq/kg) compared to traditional practices (Micropterus salmoides: 5.672 kg CO₂-eq/kg; E. ferox seed: 0.297 kg CO₂-eq/kg). It also lowered production costs, increased profits, and mitigated GHG emissions by using E. ferox and lotus ponds as treatment facilities and reducing fertilizer use. The ecological model showed lower unit costs and higher profits (Micropterus salmoides: 4.01 RMB/kg vs. 2.46 RMB/kg; E. ferox seed: 2.53 RMB/kg vs. 1.93 RMB/kg) than those of the traditional mode. This study underscores the potential of ecologically integrated modes to mitigate water pollution and carbon emissions in agriculture, offering a sustainable solution to meet the rising demand for aquatic products. Full article