Biogas is a gas produced by anaerobic activity with the process of decomposition (degradation) of organic materials. Biogas can be produced from several sources of methane, including domestic ...(household) waste, biodegradable waste, animal waste, or organic wastes that can be decomposed under anaerobic conditions. This study aims to determine the effect of various conditions (time, pH, stirring time and the type and concentration of inoculum) on biogas production and to analyze the optimum conditions in the biogas production process. This research was conducted with the factors that influence the process of making biogas. Based on the analysis results obtained several processes in the production of biogas, among others, hydrolysis, acetogenesis, asedogenesis, and methanogenesis. The results of the previous experiment were the optimal biogas research from tofu liquid waste, biogas produced with a volume of 26,700 ml, within 36 days and was obtained using an operating temperature of 35-40ᵒC and using cow dung inoculum, and using a 36 liter digester.
Black soldier fly (BSF) larvae composting is a promising waste treatment that can add value to available biodegradable waste. However, substrates that have low protein content and contain complex ...molecules (e.g. fruit peels) are not easily degraded by the larvae. This study evaluated the impact on the BSF larvae composting efficiency of co-composting different mixtures of banana and orange peels with incremental increase of fish waste. Mixtures (in total 50 distinct mixtures) of varying proportions of banana peels, orange peels and fish waste were evaluated. BFSL fed on orange peel and banana peel mixtures, containing no fish waste, resulted in a lower biomass conversion efficiency (4.5% ± 1.3) on a volatile solids (VS) basis (BCEvs). Co-composting the fruit peels with fish waste increased the biomass conversion efficiency and the highest BCEvs (25%) was attained when 75% fish waste was included. However, the BCEvs varied greatly (18.0% ± 5.8), likely due to varying fish waste composition. A 25% fish waste inclusion resulted in more than twice as high BCEvs (12.3% ± 2.1) compared to when no fish waste was included. As the conversion efficiency variance increased with increasing fish waste inclusion, it was recommended to keep the inclusions of the fish waste to around 25% of the total mixture, in order to increase the reliability of the BSF larvae composting efficiency.
•BSF larvae cannot consume and do not survive on fish waste alone.•Nutrient-imbalanced waste intake by BSF larvae improved by co-composting.•Inclusion of 25% fish waste resulted in 2.7-fold increase in BCEvs.•BCEvs variance increased with increasing fish waste inclusion.•Maximum of 25% BCEvs (4-fold increase) achieved from 75% fish waste inclusion.
This research comparatively investigates fifteen national-level integrated municipal solid waste (MSW) management schemes and determines the most preferable MSW scheme that attaches equal importance ...to the environmental, economic, and social impacts. The fifteen schemes are one business as usual (BAU) scheme, seven composting- and seven biogas production-oriented schemes. All the MSW schemes rely on incinerators and refuse derived fuel (RDF) processing for waste disposal. The environmental impacts and costs are quantified by Stepwise2006 based on ecoinvent database. The economic return is evaluated based on the net present value of the construction and operation cost. The affected local community area is the indicator of public perception toward the waste disposal projects (i.e., social impact). The analytic hierarchy process (AHP) is used to determine the most preferable scheme. The results showed that MSW combustion by incineration and RDF is the main contributor of environmental impacts. The environmental costs of composting schemes were lower than those of biogas production schemes. Total environmental cost of scheme 7 (i.e., 25% recycling, 50% decomposing, 5% biogas production, two incineration plants, and seven RDF plants) is the lowest (7492.63 billion THB2020). The cash inflow of BAU is lowest and the cash outflow is highest. In comparison with the biogas production schemes, the cash inflows and outflows of composting schemes are lower. Scheme 7 is the most preferable MSW management scheme, given the highest AHP priority score (0.228). Therefore, the composting-incineration-RDF scheme (scheme 7) should be adopted to treat biodegradable and combustible waste.
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•Most preferable national-level integrated MSW management scheme is identified.•The assessment is based on both environmental and socioeconomic aspects.•This assessment approach is comprehensively applicable for other countries.•Composting is most environmentally and economically suited to biodegradable waste.•Incineration-RDF is environmentally and socioeconomically suited to combustible waste.
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•Pollutants degradation mechanism, drilosphere concept and vermicast physical-microbial properties.•Vermicomposting and vermifiltration to manage various industrial solid and liquid ...waste, respectively.•Biochar application to enhance vermicomposting process and Greenhouse Gas (GHG) emission.•Humic acid formation and heavy metals uptake mechanism by earthworm.
As the solid waste generation rate is being increased in the world day by day, it poses serious threats to the environment. If proper care would not be taken, biodegradable pollutants will impart an obnoxious order and create an unhygienic condition. Composting and vermicomposting are two major economically affordable and environmentally sustainable technologies for the treatment of biodegradable solid waste. The focus of this review is to evaluate the feasibility of vermitechnology as a means to recover nutrients from organic waste and returning those to the environment. The review focused on mechanisms of vermicomposting process, various affecting factors and physical-microbial properties of vermicast. Apart from this, the paper also includes a brief discussion of the drilosphere concept, heavy metals uptake mechanism and physicochemical changes of raw materials during vermicomposting. Based on the reviews, recommendation has been made for future research in the field of vermicomposting.
There is a lack of knowledge about the composition and particle size distribution of the <80 mm fraction mechanically separated from residual municipal solid waste (rMSW) and the stabilized residual ...(SR) after aerobic stabilization in a full-scale MBT plant. Therefore, the composition of the particle size fractions (>60 mm, 60–40 mm, 40–10 mm) of the <80 mm fraction and SR, collected in all seasons (summer (S), autumn (A), winter (W), spring (Sp)), was determined. Biodegradable waste (vegetable waste, other organic waste, paper, cardboard) constituted from 44.1% (A) to 54.3% (Sp) of the <80 mm fraction and it decreased to 8.5% (W) to 17.1% (S) in the SR, after effective biodegradation. In SR, the smaller particle size fractions (up to 40 mm) predominated. The main contaminants in SR were plastic, glass, metal, and other waste. Hierarchical clustering indicated that the composition of the particle size fractions of SR was more similar across four seasons than that of the <80 mm fraction. After stabilization and separation, the share of contaminants increased in the SR size fractions, which means that their recovery before landfilling may be profitable. This suggests a new direction in waste management that would be consistent with the principles of a circular economy, in which a waste product, like SR, which previously could only be landfilled, becomes a source of secondary materials.
Nowadays, waste-to-energy has become a type of renewable energy utilization that can provide environmental and economic benefits in the world. In this paper, we evaluated the quality of twelve ...biodegradable waste samples from Myanmar by binder laboratory heating and drying oven at 105 °C. The calculation methods of the Intergovernmental Panel on Climate Change (IPCC) and Institute for Global Environmental Strategies (IGES) were used for the greenhouse gas emission estimation from waste disposal at the open dumpsites, anaerobic digestion, and waste transportation in the current situation of Myanmar. Greenhouse gas (GHG) emission and fossil fuel consumption of the improved biodegrade waste utilization system were estimated and both were found to be reduced. As a result, volume and weight of the biodegradable wastes with 100% moisture reduction were estimated at approximately 5 million cubic meters per year and 2600 kilotonnes per year, respectively, in 2021. The total GHG emissions in the current situation amounted to approximately 1500 and 1800 Gigagrams of CO2-eq per year in 2019 and 2021, respectively, while the total GHG emission avoidance from a sustainable approach amounted to 3500 and 4000 Gigagrams of CO2-eq per year, respectively. The study aimed at highlighting the utilization of biodegradable wastes as a clean energy source in developing countries.
High-density polyethylene (HDPE) geomembranes are often used as a liner in different applications, such as hazardous waste landfills, mining, water conservation, and waste ponds. The service exposure ...of materials causes thermal and oxidative degradation, changing the morphological structure of the polymer. This paper analyzed the final condition of an exhumed HDPE geomembrane sample that was 0.8 mm thick. The sample was collected from a biodegradable waste pond in the pond's slope, which was in contact with the waste and environmental conditions during the 15.17 years of field exposure. Physical and thermoanalytical evaluations of the sample were carried out. The analyses demonstrated that the brittle tensile behavior was observed by the low tensile elongation (259.24%) and the low-stress crack resistance (SCR) value (8.89 h). The high-density value (0.965 g cm−3) corroborates with the high crystallinity of the sample (57%). The standard oxidative induction time (Std. OIT) test result (6.94 min) demonstrated the resin's unprotection against oxidative degradation. Besides, the DMA results demonstrated an interaction of the impregnated material with the polymer. The final condition of the exhumed HDPE geomembrane analyzed can cause a rupture, generating an environmental impact on the site.
The concept of integrated solid waste management is based on the strategies of waste prevention, waste reduction, reuse, recycling (including composting), incineration and disposal at existing ...landfills. Solid waste characterization is the basis for integrated solid waste management. It is important to identify the solid waste composition for the determination, planning and implementation of any solid waste management system. In order to ensure a cleaner environment and lower greenhouse gas emissions; Turkey requires more robust and coherent strategies regarding the solid waste management system. In order to plan an efficient integrated solid waste management system and ensure a circular economy, it is necessary to include all the materials and production resources in the solid waste stream. The first step in waste management studies is to determine the waste characteristics. The characterization study performed by ISTAC includes the determination of the timing and the selection of neighborhoods of the waste to be collected, collection of representative samples of unprocessed waste, manual sorting of the waste into individual waste components, data collection, laboratory analysis and reporting of the results. The characterization results have been analyzed and suggestions on the sustainable management of biodegradable waste have been introduced. This paper focuses primarily on Biodegradable Municipal Waste (BMW), which is produced largely by households and commerce.The National Strategy on Biodegradable Waste has to set out and enforce a range of measures to meet EU’s ambitious diversion targets. The key to success is for all involved– local authorities, waste operators, businesses and householders – to play their part in the successful implementation of the full range of integrated waste management options. Even though there are legislations, broad support in their implementation should be provided by the Government.
This research investigated the cost-effectiveness of twenty-four municipal solid waste (MSW) disposal schemes for four per capita income groups (low, lower-middle, upper-middle, and high income ...groups) using life cycle cost assessment (LCCA). In the study, the LCCA included cash inflow (sales of recycle materials, fertilizer, and surplus electricity), cash outlay (investment and operation and maintenance costs), and environmental costs (based on environmental impacts). The life cycle environmental impacts and costs assessments were carried out using Stepwise2006. The most environmentally and financially preferable MSW disposal scenarios were determined for all four income groups. The LCCA was further applied to existing LCA-based studies on MSW management in India (a lower-middle income country) and Brazil (an upper-middle income country), and results were compared with the original LCA-based findings. The results showed that the environmental impacts of disposal schemes of the lower income groups were the lowest, while the cost-effectiveness were the highest (−284.79 to −1698.77 US$2019 per ton). The findings also revealed that the environmental impacts and per capita income were positively correlated. Composting biodegradable waste (320.16–402.40 US$2019 per ton) and landfilling combustible waste (312.87–350.06 US$2019 per ton) incurred the lowest total environmental costs. The most environmentally and financially preferable MSW disposal scenarios for all four income groups were the disposal scheme that integrates multiple waste disposal processes, including recycling for recyclable waste, incineration for combustible waste, composting for biodegradable waste, and landfill for non-recyclable and non-combustible waste, given the high financial gains and low environmental costs. In essence, LCCA takes into account both the financial and environmental costs, thus closely reflecting the actual cost of MSW management. Therefore, policymakers should adopt the LCCA method in the formulation and implementation of the national MSW management policy and action plans.
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-This study analyzes 24 hypothetical disposal scenarios and discusses two case studies.-The environmental impacts are assessed by LCA and the cost-effectiveness by LCCA.-The LCCA as criterion for selecting MSW management should include environmental costs.-The recycling-landfill schemes have the lowest total environmental costs.-The most desirable disposal scenario is integrated incineration-composting scheme.
Solid waste management (SWM) is one of the most neglected aspects and becoming a challenge for India as well as other developing nations' environment. India is one of the world's large and ...fastest-growing economy. Based on the trends in different nations like the US, China and European countries, it is clear that a developing economy of the nation and population of the country is also playing a vital role in the increasing rate of solid waste generation. Unsegregated waste is the root cause of the inefficient municipal solid waste management (MSWM) systems in India. The existing approach to managing the MSW such as collection, transportation and treatment results in poor utilization of resources. This review paper addresses the current status of MSWM in India. In this paper, various issues and challenges to obtain 100 % source segregated municipal solid waste are also discussed through different cases of urban areas. A way forward through an overview of the municipal waste management policies and practices adopted is being presented in the paper.
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