Search Results (324)

Inadequate Municipal Solid Waste (MSW) management constitutes a critical environmental challenge, as approximately 40% of waste reaches uncontrolled disposal sites where open-air incineration generates significant air, soil, and water pollution. The objective of this study was to evaluate the MSW Environmental Management System (EMS) in Chilpancingo de los Bravo, Guerrero, Mexico, through sustainability indicators and applicable Mexican environmental regulations to identify operational and structural deficiencies that guide a comprehensive improvement in its management. The methodology comprised an analysis of the EMS via the Municipal Development Plan, the identification of environmental indicators and applicable Mexican standards, and an evaluation of the EMS through waste characterization and sustainability metrics. A sample of 208 kg was defined in accordance with standards NMX-AA-015-1985 and NMX-AA-022-1985. The results indicate a generation rate of approximately 350 tons per day (1.2 kg/capita/day), with municipal collection coverage of 70% of the territory across 24 daily routes operated by 30 vehicles. Indicators revealed a recycling rate of 4.86%, collection coverage of 79.66%, a 0% treatment rate due to the absence of composting or material recovery facilities, and 95% of waste directed to the Final Disposal Site (FDS). These findings demonstrate substantial deficiencies in the current EMS, highlighting that the systematic application of indicators is an effective diagnostic tool for identifying gaps and guiding evidence-based improvements in MSW governance. Full article

In municipal wastewater treatment plants (WWTPs), anaerobic digestion of municipal mixed sludge (MMS) often yields low energy recovery and operational instability due to imbalances between primary and secondary sludges. Anaerobic co-digestion (AcoD) with readily biodegradable wastes, such as fruit and vegetable waste (FVW), can enhance process stability and biogas production. Life cycle assessment (LCA) methodology is used in this study to evaluate the environmental performance of implementing AcoD of MMS and FVW in a municipal WWTP, compared with a business-as-usual scenario combining mono-digestion of MMS and incineration of FVW. The LCA was modelled in openLCA 2.5 using the ecoinvent 3.9.1 database (cut-off allocation approach), and impacts were assessed with the ReCiPe 2016 Midpoint (H) method, focusing on climate change, terrestrial acidification, fossil fuel depletion, and marine eutrophication. Results indicate that AcoD reduces impacts across all environmental categories, mainly due to higher biogas yields that increase on-site electricity generation and decrease reliance on grid electricity. Improved total solids removal also lowers digestate production and composting-related burdens. Electricity consumption remains the main hotspot in both scenarios, highlighting the importance of energy efficiency and electricity mix. Sensitivity analysis on methane content (61–65% v/v) confirms the robustness of AcoD’s environmental benefits. Full article

Latin America faces growing challenges in the management of municipal solid waste (MSW). This is particularly evident in medium-sized and metropolitan cities where rapid urbanization, limited infrastructure, and high proportions of organic waste (40–70%) converge. This review synthesizes the most recent advances in organic waste management, valorization strategies, environmental performance, and policy frameworks in Mexico and Latin America. To provide a comprehensive overview, evidence from studies on informal recycling systems, route optimization, sustainable landfill siting, food waste valorization, life cycle assessments (LCAs), and biogas production is integrated. Techno-economic analyses of energy recovery from organic fractions are specifically reviewed. This review highlights that valorization of organic waste through composting, anaerobic digestion, food supplementation, and bioproduct generation can reduce greenhouse gas emissions by 40–70% compared to landfilling, with AD–composting hybrids achieving the highest reductions of 60–70%. Community composting achieved moderate reductions, 30–50%, but at significantly lower cost and with greater social co-benefits. These alternatives for valorizing the organic fraction extend the lifespan of both confined and open landfills. It also contributes to mitigating the public health impacts related to open dumping, disease vectors, and contaminated leachate. In short, this review also highlights shortcomings in policy coherence, financial mechanisms, source separation, and technology adoption. A strategic framework is proposed that prioritizes decentralized treatment systems, the integration of informal recyclers, tax incentives, community-based waste separation, and planning based on Life Cycle Assessment (LCA). The findings point to a viable strategy for transitioning from landfill dependency to circular waste management systems that improve the quality of life for the population of Latin America and the Caribbean. Full article

The limited existing studies elucidate the significant contribution of open dumpsites to greenhouse gas emissions in Sri Lanka and underscore the necessity of improved waste management practices. Considering this, this study formulates and implements a scenario-based transition framework to assess the potential for reducing greenhouse gas emissions by diverting biodegradable waste in a semi-urban governance setting in Sri Lanka, which is marked by data limitations and operational challenges. This study concludes that the environmental feasibility analysis reinforces the potential benefits of solid waste compost adoption in municipal solid waste management and agriculture. Greenhouse gas emissions (CO₂, CH₄, and N₂O) were analyzed using the IPCC Tier 1 methodology. The findings revealed that the total emissions declined significantly from 163.10 tonne CO₂ eq/month to 99.31 tonne CO₂ eq/month. The results indicate that diverting biodegradable waste to composting can play a crucial role in climate mitigation in semi-urban contexts, while promoting organic farming. These findings represent the first scenario-based GHG quantification in a semi-urban context in Sri Lanka, addressing a governance level that has received negligible attention in the composting and waste management literature. The scenario-based evaluation framework offers indicative guidance for municipalities in similarly constrained developing contexts, although direct applicability is contingent on comparable waste compositions, governance structures, and operational conditions. Full article

Separate collection and treatment systems for municipal solid waste (MSW) are designed to support efforts in sustainability. Biowaste accounts for the majority of MSW; thus, its proper management is essential. This study analyzes the impact of the presence of composting or anaerobic digestion (AD) facilities on MSW management. The management systems in Poland with composting and AD facilities were compared. Five fractions, including mixed/residual waste and biowaste, were collected in the analyzed regions; however, the rules for sorting biowaste varied. A drop in the collected residual/mixed MSW was noticed (by 3.8% to 6.6% year-on-year), while the biowaste stream increased, resulting in a 4–10% increase in the share of biowaste. The proportion of the organic fraction in biowaste was found to be 85–88%, but the proportion of food waste was slightly higher in the region with an AD facility (by about 3%). Plastics were the primary contaminants, accounting for approximately 5.5%. The presence of AD facilities has a positive impact on MSW management, including higher biowaste collection levels (67.5 kg per person versus 48.1 kg per person). Furthermore, under comparable regional conditions, economic gains were observed, such as relatively lower gate fees for biowaste (about 57 EUR per ton versus about 62 EUR per ton) and greater differences in fees between biowaste and residual/mixed MSW (about 80 EUR per ton versus about 14 EUR per ton). Full article

Ammoniacal nitrogen (NH₃-N) is a major pollutant in municipal, industrial, and agricultural wastewaters and is a key driver of eutrophication and aquatic ecosystem degradation. This review paper assessed the potential of water hyacinth (Eichhornia crassipes) as a sustainable phytoremediation option for removing ammoniacal nitrogen from wastewater. This paper focused on the plant’s biological characteristics, nutrient uptake pathways, and adaptability to varying environmental conditions. Specific mechanisms examined include direct root uptake of ammonium, internal translocation, and microbial-assisted nitrification and denitrification within the rhizosphere. The influence of pH, temperature, salinity, retention time, and plant density on removal efficiency was also assessed in this study. Across laboratory, pilot, and field-scale studies, water hyacinth achieved ammoniacal nitrogen removal efficiencies ranging from 74% to 97% under favorable conditions, alongside significant reductions in biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total dissolved solids (TDS). Integration with constructed wetlands, microbial systems, and hybrid treatment approaches further enhanced nitrogen removal and process stability. This paper also highlighted opportunities for biomass valorization through biogas, bioethanol, and compost production while identifying challenges related to salinity sensitivity and biomass management. Overall, water hyacinth emerges as a cost-effective, nature-based solution for decentralized wastewater treatment, with strong potential to support sustainable water management and circular bioeconomy initiatives. Full article

The municipal solid waste management sector is a nationally significant greenhouse gas source in Sri Lanka, yet decision makers lack comprehensive, city-level life-cycle assessment of full waste management chains. This study quantifies and compares greenhouse gas emissions and mitigation potential of alternative waste management scenarios for Colombo and Kandy, supporting nationally determined contributions (NDC) 3.0. Using IPCC 2021 GWP100 V1.03 as the impact assessment method, six scenarios were assessed, including business-as-usual, recycling, composting, confined cover windrow composting, anaerobic digestion, refuse-derived fuel production, incineration, pyrolysis, co-processing in cement kilns, open dumping, and sanitary landfilling. The business-as-usual scenario, dominated by open dumping, resulted in the highest greenhouse gas emissions in both Colombo and Kandy. In contrast, the integrated waste management approach (Scenario 3), combining anaerobic digestion, confined cover windrow composting, refuse-derived fuel production, and enhanced recycling, converted both cities from net emitters to net carbon sinks. Over the projection period of 2026–2035, this transition is expected to deliver substantial cumulative emission reductions, contributing significantly toward achieving NDC 3.0 waste sector targets in Sri Lanka despite the relatively small share of national baseline emissions in the sector. These findings highlight the strong mitigation potential of integrated waste management systems for advancing low-carbon urban strategies. Full article

This study assesses the distribution of nutrients, trace elements, and heavy metals across different granulometric fractions of municipal solid waste (MSW) compost from three regions: Kaunas and Alytus (Lithuania) and Daugavpils (Latvia). Samples were collected from mechanical biological treatment plants (MBTPs) and fractionated into six different granulometric fractions (>5 mm, 5–2.5 mm, 2.5–1 mm, 1–0.5 mm, 0.5–0.2 mm, and <0.2 mm). Each fraction was subjected to physicochemical characterization. Macronutrients (Ca, K, Mg, P), trace elements (Al, As, Co, Fe, Mn, Mo), and heavy metals (Cd, Cr, Cu, Ni, Pb, Zn) were analyzed using ICP-OES in triplicate. Results showed that essential nutrients and toxic metals were retained more in the finer fractions (<1 mm). In contrast, undesirable impurities, mainly glass, were retained in the coarse fractions across all the studied areas. All fractions in the compost samples of Kaunas, and coarse fractions (>5 mm, and 5–2.5 mm) of Alytus and Daugavpils are suitable to use as a soil amendment only if the undesirable impurities are removed to the acceptable limits in the coarse fractions. The fine fractions of Alytus have higher levels of heavy metals (Cd, Cr, Cu, Ni, Pb, Zn), while Daugavpils showed higher levels of Cd, Cu, Ni, and Zn, exceeding the EU limits. Regarding physical fractionation, results showed that nutrients and heavy metals increased in the compost as particle size decreased. Our findings suggest that removing particle sizes < 1 mm and large impurities from the coarse fractions can enhance compost quality. Overall, particle-size fractionation can improve the consistency and safety of MBT-derived MSW compost for reuse in circular waste management systems. Full article

Growing pressures on water resources, exacerbated by climate change, resource depletion, and population growth, underline the need for sustainable and energy-efficient wastewater management. Wastewater treatment plants (WWTPs) are among the most energy-intensive elements of the Integrated Water Service, and their environmental performance depends on infrastructure design, resource availability, and treatment configuration. Improving resource efficiency while reducing energy demand and environmental impacts is therefore a priority for water utilities seeking innovative decision-support tools. Within the national project “WATERGY—Energy Efficiency of the Integrated Water Service”, this study proposes a life-cycle-based framework to assess the sustainability of technological interventions in WWTPs. A comparative gate-to-grave Life Cycle Assessment (LCA) was applied to the municipal WWTP of Potenza (Southern Italy). Three sludge End-of-Life Scenarios were assessed: the current landfill-based configuration, an enhanced oxygenation–nitrification setup, and anaerobic digestion with biogas-based cogeneration. Compared to the current scenario, anaerobic digestion with cogeneration reduces Global Warming Potential by 17% and decreases freshwater ecotoxicity by approximately 30%. Compost production shows the highest reduction in ecotoxicity (−51%) but increases fossil resource depletion and acidification due to higher energy demand. Overall, energy recovery pathways, particularly anaerobic digestion with cogeneration, provide the most balanced environmental benefits, supporting more sustainable WWTP operation within the Integrated Water Service. Full article

Egypt’s municipal solid waste (MSW) sector faces persistent challenges due to increasing generation rates, limited recovery, and a high organic fraction, motivating the selection of appropriate biological treatment options within Mechanical–Biological Treatment (MBT) systems. This study compares composting-based MBT and biodrying-based MBT for a case application in Alexandria, Egypt, using an integrated techno-economic and greenhouse gas (GHG) assessment. Discounted cash-flow modelling was applied using defined CAPEX and OPEX, along with revenue from recovered products. GHG accounting used documented emission factors and activity data against an unmanaged landfill baseline representative of current disposal practices. The system boundary covers waste reception and mechanical processing, biological treatment, process energy use, and residual disposal. Results show that composting achieves higher financial performance (NPV USD 2.55 million) than biodrying (NPV USD 0.99 million), while delivering a 48.5% reduction in net system GHG emissions relative to the baseline. Sensitivity analysis indicates that the comparative ranking is primarily driven by electricity prices, revenue assumptions, CAPEX, and baseline-related emissions parameters. Under the defined assumptions, composting is the preferred MBT biological pathway for the analyzed case, and interpretations are limited to the evaluated boundaries. Full article

The organic fraction of municipal solid waste (OFMSW) compost has the potential to be an effective soil improver, and agriculture is the industry with the largest potential market for its adoption, followed by landscaping and gardening hobbyist uses. Understanding which factors foster the intention to adopt OFMSW compost among users engaged in agricultural activities is, therefore, crucial for its diffusion. A paper-and-pencil questionnaire was administered to 119 visitors involved in farming activities at an exhibition focused on the green and circular economy. The PROCESS macro for SPSS model 8 was applied to test a moderated mediated model to investigate the relationship between being a professional or hobby farmer, perceived drivers and the intention to adopt compost, with the moderation of the frequency of exposure to different information sources. The results showed that hobbyists perceived more drivers for compost adoption. In turn, the perceived drivers had a positive impact on users’ intention to adopt. Moreover, with a low frequency of use of information sources, professionals perceived fewer advantages of compost adoption. The present study highlighted the need to enhance discussions about compost properties and benefits, especially for professional farmers. Full article

Fertilization management is crucial mainly during the walnut training phase in order to obtain good plant formation, which is essential for guaranteeing future optimal yield. The aim of the present experiment was to evaluate the effect of different organic amendments on plant nutritional status and soil fertility in young bearing walnut trees. The experiment was conducted in 2023 and 2024 on walnut trees of the cultivar Chandler grafted on Juglans regia, planted in 2021. Since 2023, plants were yearly treated as follows: 1. non-fertilized control; 2. mineral fertilization; 3. application of municipal solid waste compost; and 4. application of compost from agri-food chain scraps. Soil amendments were supplied at the same rate as mineral fertilizer (120 kg N ha⁻¹) in spring on the tree row on a 1.5 m wide strip, while mineral fertilizer was split in two applications (50% in spring and 50% in summer). Plant growth, measured with trunk diameter and pruning wood weight, was enhanced by mineral fertilization, followed by compost, in comparison to the control. Soil mineral N was too high in relation to plant needs, with a consequent increase in the risk of nitrate leaching. Organic amendments increased soil nutrient availability, microbial activity, and carbon concentration, which, in the long term, could provide a positive environmental effect related to its sequestration into the soil. Full article

Biodegradable waste is commonly treated as a problem to be managed, but it can be a valuable resource when considered within a circular bioeconomy perspective. This article develops a practical and systems-based frame work for integrating biodegradable waste, ranging from municipal food scraps to wastewater biosolids, into valuable resources. It explores real-world strategies for transforming waste into value-added products, including composting, anaerobic digestion, biochemical conversion, and the creation of bio-based materials. The review also highlights key drivers and barriers, including technical, regulatory, and social factors, which shape the feasibility and impact of circular solutions. A visual model illustrates the full cycle, from identifying waste streams to reintegrating recovered resources. The paper also highlights case studies from Toronto, Milan and Brazil as examples of successful implementation. Overall, this paper emphasizes a pragmatic yet regenerative shift toward organic resource recovery aligned with sustainability and decarbonization goals. Full article

Italian inner areas face population decline, limited access to services and fragile infrastructure; however, the micro-mechanisms through which community practices generate tangible improvements often remain unclear. Still, local communitarian initiatives, such as those represented by ecovillages, can be an effective response to the ongoing process of marginalisation, becoming true living labs for place-based transitions. Through the analysis of the Torri Superiore Ecovillage (Imperia, Italy), a recognised and well-known good practice in the national and international ecovillage circuit, we want to find answers to three research questions: (RQ1) To what extent can an ecovillage act as a living lab for social innovation and ecological transition in inner areas? (RQ2) Which demographic and governance conditions enable territorial resilience and which ones block it? (RQ3) Which environmental practices generate locally significant improvements and with what limitations? Based on qualitative and interpretative evidence (2016–2025)—field observations, internal documents and testimonies—and on essential demographic indicators (ISTAT/SNAI), this study examines the Torri Superiore Ecovillage as a small-scale living lab. Torri Superiore and the surrounding municipalities are ageing and have reduced demographic bases; however selective immigration and heterogeneity of skills act as partial buffers. The governance of the Torri Superiore Ecovillage combines clear rules, participatory routines and coordination mechanisms, promoting problem solving while remaining sensitive to leadership burdens. The “bridging” between multiple actors enables terrace maintenance, local water resource management, agroecological practices, renewable energy adoption, waste prevention/composting and light mobility to achieve tangible environmental improvements on a small scale. We frame transferability as analytical (not statistical), specify the enabling conditions (sufficient active participants, stable routines, territorial management) and outline the relevant policy implications for SNAI classes and a lightweight longitudinal observatory. Full article

Background: Municipal solid waste management is a relevant component of climate and air quality policy, yet published life cycle assessments report inconsistent conclusions on whether sanitary landfilling, waste-to-energy incineration, composting, or anaerobic digestion yields the lowest greenhouse gas and co-pollutant impacts because results depend strongly on methodological choices and local context. Objective: To synthesize and critically evaluate how key life cycle assessment assumptions and boundary decisions influence reported emissions across major waste management pathways, with primary emphasis on the United States and selected comparison to European Union policy frameworks. Methods: Peer-reviewed life cycle assessment studies and supporting technical and regulatory sources were reviewed and compared, focusing on functional unit definition, system boundaries, time horizon, energy substitution and crediting methods, and treatment of methane, nitrous oxide, and air pollutant controls; drivers of variability were identified through structured cross study comparison and sensitivity-focused interpretation. Results: Reported pathway rankings vary primarily with landfill gas collection and utilization assumptions, the carbon intensity of displaced electricity or heat for waste-to-energy systems, and the representation of biological process emissions across active and curing stages; harmonized comparisons reduce variability but do not yield a single consistently superior pathway across all plausible settings. Conclusions: Comparative conclusions are context-dependent and policy-relevant interpretation requires transparent reporting and sensitivity analysis for capturing efficiency, substitution factors, and biological emission controls, along with clear alignment between modeled scenarios and real-world operating conditions. Full article