Municipal Solid Waste Treatment System Research Articles

From air to airway: Dynamics and risk of inhalable bacteria in municipal solid waste treatment systems

Municipal solid waste treatment (MSWT) system emits a cocktail of microorganisms that jeopardize environmental and public health. However, the dynamics and risks of airborne microbiota associated with MSWT are poorly understood. Here, we analyzed the bacterial community of inhalable air particulates (PM10, n = 71) and the potentially exposed on-site workers’ throat swabs (n = 30) along with waste treatment chain in Shanghai, the largest city of China. Overall, the airborne bacteria varied largely in composition and abundance during the treatment (P < 0.05), especially in winter. Compared to the air conditions, MSWT-sources that contributed to 15 ∼ 70% of airborne bacteria more heavily influenced the PM10-laden bacterial communities (PLS-SEM, β = 0.40, P < 0.05). Moreover, our year-span analysis found PM10 as an important media spreading pathogens (104 ∼ 108 copies/day) into on-site workers. The machine-learning identified Lactobacillus and Streptococcus as pharynx-niched featured biomarker in summer and Rhodococcus and Capnocytophaga in winter (RandomForest, ntree = 500, mtry = 10, cross = 10, OOB = 0%), which closely related to their airborne counterparts (Procrustes test, P < 0.05), suggesting that MSWT a dynamic hotspot of airborne bacteria with the pronounced inhalable risks to the neighboring communities.

Environmental sustainability in the city of Shanghai municipal solid waste treatment system: an integrated framework of artificial neural network (ANN) and LCA-emergy methodology

Environmental sustainability in the city of Shanghai municipal solid waste treatment system: an integrated framework of artificial neural network (ANN) and LCA-emergy methodology

Can waste management system be a Greenhouse Gas sink? Perspective from Shanghai, China

Municipal solid waste (MSW) properties and parameters for MSW treatment technologies are decisive for GHG emission of MSW treatment systems. But they are changing in China due to MSW source segregation and technological advancements, which requires new studies on GHG emissions of MSW treatment systems based on up-to-date data. In this study, GHG emission values and their uncertainties of waste treatment systems before and after MSW source segregation in Shanghai were analyzed utilizing Life Cycle Assessment (LCA) methods and Monte Carlo analysis. The results showed that before waste segregation, 21.0∼319 kg CO2-eq GHG per tonne was emitted and that -139∼203 kg CO2-eq GHG per tonne was emitted after waste source segregation. The source segregation helps to reduce GHG emissions from MSW treatment systems. In the long run, waste to energy incineration was not recommended from GHG perspective and anaerobic digestion has a great potential for GHG emission reductions.

Exergetic sustainability analysis of municipal solid waste treatment systems: A systematic critical review

The growing volume of municipal solid waste (MSW) generated worldwide often undergoes open dumping, landfilling, or uncontrolled burning, releasing massive pollutants and pathogens into the soil, water, and air. On the other hand, MSW can be used as a valuable feedstock in biological and thermochemical conversion processes to produce bioenergy carriers, biofuels, and biochemicals in line with the United Nations’ Sustainable Development Goals (SDGs). Valorizing MSW using advanced technologies is highly energy-intensive and chemical-consuming. Therefore, robust and holistic sustainability assessment tools should be considered in the design, construction, and operation phases of MSW treatment technologies. Exergy-based methods are promising tools for achieving SDGs due to their capability to locate, quantify, and comprehend the thermodynamic inefficiencies, cost losses, and environmental impacts of waste treatment systems. Therefore, the present review paper aims to comprehensively summarize and critically discuss the use of exergetic indicators for the sustainability assessment of MSW treatment systems. Generally, consolidating thermochemical processes (mainly incineration and gasification) with material recycling methods (plastic waste recovery), heat and power plants (steam turbine cycle and organic Rankine cycle), modern power technologies (fuel cells), and carbon capture and sequestration processes could improve the exergetic performance of MSW treatment systems. Typically, the overall exergy efficiency values of integrated MSW treatment systems based on the incineration and gasification processes were found to be in the ranges of 17–40% and 22–56%, respectively. The syngas production through the plasma gasification process could be a highly favorable waste disposal technique due to its low residues and rapid conversion rate; however, it suffers from relatively low exergy efficiency resulting from its high torch power consumption. The overall exergy efficiency values of integrated anaerobic digestion-based MSW processing systems (34–73%) were generally higher than those based on the thermochemical processes. Exergy destruction and exergy efficiency were the most popular exergetic indicators used for decision-making in most published works. However, exergoeconomic and exergoenvironmental indices have rarely been used in the published literature to make decisions on the sustainability of waste treatment pathways. Future studies need to focus on developing and realizing integrated waste biorefinery systems using advanced exergy, exergoeconomic, and exergoenvironmental methods.

Multi-objective optimization of technology solutions in municipal solid waste treatment system coupled with pollutants cross-media metabolism issues

The environmental impact, energy conservation, and economic cost are prominent decision criteria in municipal solid waste (MSW) management, among which trade-off relationships widely exist because of different features of pollutant treatment technologies. These three objectives should thereby be simultaneously considered in the design of technology combinations in MSW treatment system (MSWTS). In addition, comprehensive characterization of environmental impact of the whole MSWTS should cover the complex pollutants cross-media metabolism in the treatment of both MSW and subsequent secondary pollution. This study developed a multi-objective optimization model to select optimal technology solutions in MSWTS. Three objectives, the minimizations of total environmental impact calculated from pollutants cross-media metabolism perspective, net energy consumption, and total cost are optimized through the second generation of the Non-dominated Sorting Genetic Algorithm (NSGA-II). Final MSW management schemes under environment, energy, and cost preferences are obtained through Vlsekriterijumska Optimizacija I Kompromisno Resenje (VIKOR) method. This paper uses China's MSWTS as a case study and finds that Pareto optimal solutions can reduce the total environmental impact and the net energy consumption by 24.2% and 7.4% respectively, while increase the total cost by 18.2% in average, compared with the baseline scenario. The promotion of MSW biological treatment technologies, especially anaerobic digestion (AD), can effectively improve the environmental performance of MSWTS, while the current vigorous promotion of MSW incineration in China is not recommended. Sludge co-processing in cement kiln is highly promoted under all three types of management preferences. In summary, the proposed methodology can provide decision support for the optimal design of technology solutions in MSWTS.

Environmental Impact Evaluation of Current Municipal Solid Waste Treatments in India Using Life Cycle Assessment

An environmental life cycle assessment was conducted to compare proposed municipal solid waste treatment systems with the existing system in Visakhapatnam, India. Five waste alternative treatment systems, including open dumping of municipal solid waste (S1), landfill without gas recovery [LFWGR] (S2), landfill with gas recovery (S3), anaerobic digestion + LFWGR (S4), and incineration + LFWGR (S5). EASETECHTM was considered for assessment using ReCiPE Midpoint (Heuristic) world environmental impact assessment method. Global warming potential (GWP), terrestrial acidification (TA), freshwater eutrophication (FEW), marine water eutrophication (ME), human toxicity (HTP), terrestrial ecotoxicity (TE), freshwater ecotoxicity (FWT), and marine ecotoxicity (MET) impacts were determined for each option. The existing MSW disposal practice in Visakhapatnam city (baseline scenario, S1) has the highest GWP (1107 kg CO2 eq.), which can potentially be reduced to 68.2%, 81.5%, 98.2%, and 94.5% by alternative waste management scenarios S2, S3, S4 and S5, respectively. Scenario S4, involving the use of anaerobic digestion of food waste and residues dumped in engineered landfill without energy recovery was found to be the option with the highest mitigation potential of most of the impacts, and it contributes to significant environmental benefits in terms of ecological footprints in a low-income country such as India. Sensitivity analysis was conducted to confirm the reasonable legitimacy of data used for the determination of the impacts.

Municipal solid waste (MSW) co-processing in cement kiln to relieve China's Msw treatment capacity pressure

In many countries, like China, the huge capacity of cement industry seems to be able to absorb the booming production of municipal solid waste (MSW). However, the rapid progress of incineration facilities construction raise questions such as will there be chances of cement kiln co-processing (CKC) to be utilized and promoted as an MSW complementary technology in China, and how will it develop in the future? This paper obtained numerous up-to-date data and information as support evidences to quantitatively evaluate the MSW treatment pressure and its temporal and spatial evolution in Chinese provinces, and estimate the CKC promotion and emission reduction potential for adapting to regional MSW demand. Results showed that CKC still has a great promotion potential. China's MSW treatment system was under long-term pressure and might have a shortage of 4.50 million tons in 2020. Provincial level analysis indicated that CKC could not only completely filled the treatment gap, but also replaced 78.05 million tons of landfill capacity. The resulting environmental benefits were significant, with a reduction of 2.55E+10 kg CO2 eq. and 4.47E+07 kg SO2 eq. from a life-cycle perspective for GWP and AP etc., respectively. Hence, CKC contributed to relieving the pressure on MSW management (MSWM) and improving environmental performance. By developing more precise regional planning, some of the issues that had hindered the spread of CKC could be addressed. The main findings of this paper might be influential in guiding the universalization of CKC in China and other regions.

Embodied exergy-based analysis of a municipal solid waste treatment system with uncertainty inclusion

Embodied exergy-based analysis of a municipal solid waste treatment system with uncertainty inclusion

Embodied exergy-based analysis of a municipal solid waste treatment system with uncertainty inclusion

The development of an integrated solid waste management (ISWM) system is still a matter of interest in many countries. One of the main challenges is to efficiently allocate the material streams in order to save energy and recover materials. The aim of this paper is to use the embodied exergy criteria to evaluate the distribution of the material streams into a solid waste (SW) treatment system composed by: a mechanical biological treatment (MBT) plant for refuse derived fuel (RDF) production and a paper recycling plant for cardboard production. Two scenarios are compared, based on the inlet mass flow to the MBT plant and the cardboard production. Stochastic tools based on Monte Carlo simulation are adopted for generating simulation scenarios, in order to account for the uncertainty that occurs in external (e.g., waste composition) and internal (e.g., equipment energy consumption) parameters.

Municipal Solid Waste Treatment System——Taking Wuhan as an Example

The work presented in this paper focuses on the problem of municipal solid waste in Wuhan which is becoming increasingly serious with the continuous progress of urbanization. Through literature research, we sort out and analyze the paradigms of waste treatment system of typical cities at home and abroad. By questionnaire survey, this paper makes a comprehensive analysis of current situation of municipal solid waste management in Wuhan and draws the conclusion that the waste management system is outdated and aging due to the imperfect legal system, the weak garbage sorting consciousness of residents and so on. Based on the background of Internet of things and big data, this paper puts forward some suggestions on the construction of municipal solid waste management for Wuhan.

Life Cycle Impact Assessment of Garbage-Classification Based Municipal Solid Waste Management Systems: A Comparative Case Study in China.

Confronted with a series of problems caused by surging generation of municipal solid waste (MSW), the Chinese central and local governments have promulgated and implemented policies to deal with them, including promotions of the classification of MSW. However, to date, practical knowledge and understanding about benefits for garbage classification from its environmental performance perspective is still limited. The present study is purposed to comprehensively investigate the environmental effects of garbage classification on municipal solid waste management (MSWM) systems based on three proposed garbage classification scenarios in China, via a comparative life cycle impact assessment (LCIA). Taking advantage of Impact Assessment of Chemical Toxics (IMPACT) 2002+ method, this comparative LCIA study can quantitatively evaluate midpoint, endpoint, and single scored life cycle impacts for the studied MSWM systems. A Monte Carlo uncertainty analysis is carried out to test the effectiveness and reliabilities of the LCIA results. The LCIA and uncertainty analysis results show that MSWM systems based on various garbage classification scenarios have significant variations in the studied midpoint, endpoint, and single scored environmental impacts. Different garbage classification scenarios have their individual environmental-friendly superiority for specific impact categories. Overall, results of this study demonstrate that MSW treatment systems integrated with garbage classification are more environmentally friendly by comparison with non-classification; and that the more elaborate the level of MSW classification, the smaller its impacts on the environment.

Система обращения с твердыми коммунальными отходами и механизм ее финансирования в России: состояние и направления развития

The article examines the concept of the solid waste management system in the world practice as a basis for reforming the municipal solid waste (MSW) management system in Russia. The analysis has revealed the need for a systematic rather than a point approach to reforming the existing technological infrastructure of MSW treatment system in Russia, which will require additional funding and the development of financial instruments and economic levers applied.

Life Cycle Assessment of Refuse Derived Fuel (RDF) for Municipal Solid Waste (MSW) Management: Case Study Area Around Cement Industry, Cirebon, Indonesia

Life Cycle Assessment (LCA) is a useful tool to evaluate the environmental impact of Municipal Solid Waste (MSW) processing. Here, a BUMDES (village owned enterprise) converted MSW to Refuse Derived Fuel (RDF) in the area around a cement plant in Cirebon, Indonesia. The RDF that is produced is used as a partial substitutiton fuels for the kiln in the cement industry. The purpose of present study was to evaluate the environmental impacts of RDF production through an attributional LCA study. The results were compared with the current practice of MSW treatment system. The waste management system that will be compared includes RDF and direct combustion. LCA simulation was conducted in the OpenLCA software, which is equipped with ecoinvent database as well as primary data from the field. The company treated about 2, 259.96 kg of waste / day. The results showed that the production rate of RDF is about 966 kg / day. The analysis shows that the conversion of combustible municipal solid waste into RDF is more environmentally friendly than direct combustion with environmental impacts as follows: GWP 8.40E-01 kg CO2 eq., Acidification 4.36E-04 kg SO2 eq., Eutrophication 7.18E-04 kg PO4 eq., ODP 3.59E-09 kg CFC-11 eq., And Human toxicity 2.27E-01 kg 1.4 dichlorobenzene eq. The use of RDF as a substitute fuel for the cement industry is economically advantageous if: there are no restrictions on processed waste, the RDF product sales to the cement industry is ensured, and the RDF product price should be economically viable. The initial investment costs and high operating as well as the maintenance costs could be a challenging issue when dealing with MSW processing to RDF.

Municipal Solid Waste Treatment System Increases Ambient Airborne Bacteria and Antibiotic Resistance Genes.

Landfill and incineration are the primary disposal practices for municipal solid waste (MSW) and have been considered as the critical reservoir of antibiotic resistance genes (ARGs). However, the possible transmission of ARGs from the municipal solid waste treatment system (MSWT system) to ambient air is still unclear. In this study, we collected inside and ambient air samples (PM10 and PM2.5) and potential source samples (leachate and solid waste) in the MSWT system. The results showed that the MSWT system contributed to the increased ambient airborne bacteria and associated ARGs. Forty-one antibiotic-resistant bacteria (ARB) harboring blaTEM-1 were isolated, and the full-length nucleotide sequences of the blaTEM-1 gene (harbored by identical bacillus) from air (downwind samples) were 100% identical with those in the leachate and solid waste, indicating that the MSWT system was the important source of disperse bacteria and associated ARGs in the ambient air. The daily intake (DI) burden level of ARGs via PM inhalation was comparable with that via ingestion of drinking water but lower than the DI level via ingestion of raw vegetables. The antibiotic-resistant opportunistic pathogen Bacillus cereus was isolated from air, with a relatively high DI level of Bacillus via inhalation (104-106 copies/day) in the MSWT system. This study highlights the key pathway of airborne ARGs to human exposure.

Launch of Municipal Solid Waste Treatment System Using Existing Cement Kiln in China

Launch of Municipal Solid Waste Treatment System Using Existing Cement Kiln in China

基于混合生命周期评价的生活垃圾处理系统生态效率分析

基于混合生命周期评价的生活垃圾处理系统生态效率分析

Implementing Circular Economy in municipal solid waste treatment system using P-graph

Municipal solid waste (MSW) is one of the issues associated with the growth of economic and urban population. The aim of this study is to develop an integrated design of waste management systems in support of a Circular Economy by P-graph (a bipartite graphical optimisation tool) as an effective decision support tool. The case study considers four MSW compositions based on different country income levels. Solving the P-graph model identifies the most suitable treatment approaches, considering the economic balance between the main operating cost, type, yield, quality of products, as well as the GHG emission (externality cost). The identification of near-optimal solutions by P-graph is useful in dealing with the trade-offs between conflicting objectives, e.g. local policy and practical implementation, that are difficult to monetise. For a lower-income country, the optimal solution includes a combination of at source separation, recycling, incineration (heat, electricity), anaerobic digestion (biofuel, digestate) and the landfill. It avoids an estimated 411 kg CO2eq/t of processed MSW and achieves a potential profit of 42 €/t of processed MSW. The optimisation generally favours mechanical biological treatment as the country income level rises, which affects the composition of the MSW. The relative prices of biofuel, electricity and heat (>20%) cause a significant impact on the highest-ranking treatment structure and overall profit. This study shows that the developed framework by P-graph is an effective tool for MSW systems planning. For future study, localised data inputs can be fed into the proposed framework for a customised solution and economic feasibility assessment.

Environmental impact of carbon cross-media metabolism in waste management: A case study of municipal solid waste treatment systems in China

Waste treatment is a metabolic process that incurs pollutants migration across environmental media (i.e., air, water, and soil) and involves various conversions of physicochemical forms of carbon. Multiple forms of carbon compounds, such as CO2, CH4, CO, VOCs, and other organic matter can contribute to a series of transboundary environmental problems. However, current strategies targeting pollution reduction in single medium may cause pollution transfer to other environmental media, leading to comparatively large difficulty in assessing the related environmental impact on integrated ecosystems. This paper develops an analysis framework of carbon cross-media metabolism in municipal solid waste (MSW) treatment systems that include landfilling, composting, incineration, and anaerobic digestion. Life cycle impact analysis and sensitivity analysis methods are used to recognize the essential technologies in promoting the carbon cross-media migration and decreasing the integrated environmental impacts. The framework is implemented in a case study of the MSW treatment systems of 2013 in China. Results show that 86%–98% of carbon pollutants generated through landfilling, composting, and incineration ended up in the natural environment, while anaerobic digestion achieved an 87% pollution removal rate. Co-generation technology applied in incineration flue gas treatment, biochemical + membrane treatment technology in wastewater treatment, and co-processing of sludge in cement kilns were identified as the essential technologies affecting carbon migration across the gas-liquid, liquid-solid, and solid-gas interface, respectively. The relatively high environmental impacts of landfilling and incineration can be decreased by optimizing their technological compositions and applications. This study can provide support to replace the traditional environmental practice aiming at pollution control in single environmental medium independently by a systematic management approach that considers carbon cross-media metabolism and integrated environmental impact.

Resource impacts of municipal solid waste treatment systems in Chinese cities based on hybrid life cycle assessment

Municipal Solid Waste (MSW) management in Chinese cities is a significant challenge. However, the comprehensive resource impacts of MSW treatment systems in Chinese cities are unclear. This study presents a mixed-unit hybrid life cycle assessment for MSW treatment systems. The comprehensive resource impacts of six MSW treatment systems in China are evaluated using this method: (1) landfilling, (2) landfilling with landfill gas utilization, (3) incineration with leachate spray, (4) composting+landfilling, (5) composting+incineration, and (6) incineration with leachate centralized treatment. The results show that composting+incineration has the lowest resource impacts except for raw coal extraction. Reusing by-products of MSW treatment systems can reduce resource extraction of the entire economy. By reusing the by-products, landfilling induces the largest extraction of fossil fuels and biomass, whereas landfilling with landfill gas utilization induces the largest extraction of mineral ores. Improving the diesel efficiency of the collection and transportation process, increasing by-product recovery efficiency, and decreasing moisture content of MSW have significant impacts on reducing resource impacts of MSW treatment systems. We also observed trade-offs in resource impacts of different MSW treatment systems. Compared to landfilling, landfilling with landfill gas utilization can reduce the induced fossil fuel extraction but increase the induced metal ore extraction. We observed similar situation when comparing incineration with leachate spray with composting+landfilling.Findings of this study provide scientific foundations to improve the resource efficiency of MSW treatment systems in Chinese cities. They also provide insights into the MSW management in other countries.

The financing of the municipal solid waste treatment system in Russia: Challenges and prospects

The financing of the municipal solid waste treatment system in Russia: Challenges and prospects