Municipal Solid Waste Treatment Research Articles

Prediction and Feed-In Tariffs of Municipal Solid Waste Generation in Beijing: Based on a GRA-BiLSTM Model

To cope with the increasing energy demand of people and solve the problem of a “Garbage Siege”, most cities have begun to adopt waste power generation (WTE). Compared to other WTE technologies, incineration has proven to be the most efficient technology for municipal solid waste (MSW) treatment. Therefore, to further explore the economic feasibility of MSW incineration plant construction, this study established a multi-factor prediction of MSW generation based on the GRA-BiLSTM model. By fully considering the relationship between the change in feed-in tariff (FIT) and the building of an incineration plant in Beijing, the economic feasibility of building an incineration plant is discussed based on the three scenarios set. The experimental results showed that (1) the combined model based on the GRA-BiLSTM showed good applicability for predicting MSW generation in Beijing, with MAE, MAPE, RMSE, and R2 values of 12.47, 5.97%, 18.5580, and 0.8950, respectively. (2) Based on the three scenarios set, the incineration power generation of Beijing MSW will show varying degrees of growth in 2022–2035. In order to meet future development, Beijing needs to build seven new incinerators, and the incineration rate should reach 100%. (3) According to setting different feed-in tariffs, based on the economic feasibility analysis, it is found that the feed-in tariff of MSW incineration for power generation in Beijing should be no less than $0.522/kWh. The government should encourage the construction of incineration plants and give policy support to enterprises that build incineration plants.

Cooperative treatment and resource utilization of municipal solid waste by industrial coke ovens: Effects of doping ratio and management

For the collaborative treatment and resource utilization of an industrial coke oven on municipal solid waste (MSW), this study used MSW to prepare refuse-derived fuel (RDF). The influence of different mix ratio between RDF and coal on coking products was considered, and technical and economic analyses were conducted. The results showed that under the low mixture ratio (3%), the pyrolytic carbon obtained basically met the class III standard of metallurgical carbon. In the experiment of medium mixture ratio (25%, 30%, 35%), the product contained a certain amount of calorific value, lower than that of the metallurgical coke. It might be that the ash content increased, and such product can be used for civil coke or chemical coke. When the mixture ratio was 100%, the calorific value of pyrolysis carbon was 7.53 MJ/kg, representing 25.7% of the calorific value of ordinary coke. The gas production rate of the discharged gas was 0.35, and the calorific value is 14.0 MJ/kg, reaching 73.6% of the coke oven gas. Under the condition of no coal input, the MSW was converted into usable energy. The results demonstrated that coke oven pyrolysis with 100% RDF addition is the most feasible way to recycle resources and energy.

Forecasting the Mitigation Potential of Greenhouse Gas Emissions in Shenzhen through Municipal Solid Waste Treatment: A Combined Weight Forecasting Model

As a significant source of anthropogenic greenhouse gas emissions, the municipal solid waste sector’s greenhouse gas emission mode remains unknown, hampering effective decision-making on possible greenhouse gas emission reductions. Rapid urbanization and economic growth have resulted in massive volumes of municipal solid trash. As a result, identifying emission reduction routes for municipal solid waste treatment is critical. In this research, we investigate the potential of municipal solid waste treatment methods in lowering greenhouse gas (GHG) emissions in Shenzhen, a typical Chinese major city. The results showed that the combined treatment of 58% incineration, 2% landfill, and 40% anaerobic digestion (AD) had the lowest greenhouse gas emissions of about 5.91 million tons under all scenarios. The implementation of waste sorting and anaerobic digestion treatment of organic municipal solid waste after separate collection can reduce greenhouse gas emissions by simply increasing the incineration ratio.

Pyrolysis, a recovery solution to reduce landfilling of residual organic waste generated from mixed municipal waste

Despite policies to restrict the mixing of organic waste with other general waste and improve its separation at source, municipal solid waste still contains a high proportion of organic waste. The residual organic waste is generated as a by-product of the mechanical treatment of municipal solid waste (MSW) and is mainly disposed in landfills after composting. Its reuse and recovery status varies across European countries. Most countries restrict the use of biostabilised residual waste (BSRW) to landfill cover, whereas others have regulated it as marketable compost. Crucially, BSRW is set to lose its “recycled” status under the revised European Union waste framework, with probably tighter restrictions and increased costs imposed for the landfilling of organic waste. Our research aimed to investigate pyrolysis as an alternative technology to treat the 10–40 mm fraction of BSRW (representing 50% of BSRW generated). Pyrolysis at 700 °C was carried out and feedstock and pyrolysis products were characterized. Mass and energy balances showed that pyrolysis produced hot vapour/gas whose combustion may render the pyrolysis process energetically sustainable. Biochar comprises 30–50% of BRSW mass after removal of glass, metal and stones. Our results indicate that pyrolysis has the potential to create options for contributing to reduce the landfilling of BSRW; however, the presence of residual impurities may limit biochar applications.

Expression of Concern: Municipal solid waste treatment for bioenergy and resource production: Potential technologies, techno-economic-environmental aspects and implications of membrane-based recovery

Expression of Concern: Municipal solid waste treatment for bioenergy and resource production: Potential technologies, techno-economic-environmental aspects and implications of membrane-based recovery

Risk Management Strategies for Waste-to-Energy Projects Utilizing BOT Models

Since the 1990s, with the implementation of the reform and opening up policy, the rapid development of China's economy, the progress of urbanization is getting faster and faster, and as one of the urban wastes, the treatment of domestic waste has also attracted more and more attention. The municipal solid waste incineration treatment, and the heat generated after combustion is used to generate electricity, referred to as "garbage incineration power generation", because this way can make the waste to reduce, harmless, and can be converted into part of the electricity, because it is widely used in the treatment of municipal solid waste by local governments. Due to the shortage of government funds, most domestic waste incineration projects are implemented in BOT mode. Waste incineration power generation projects are often a large investment, for investors, the recovery period is long, the technical requirements are high, the investment agreement signed with the government is also very complex, coupled with the imperfect supporting laws and policies in China, so that the process of waste incineration power generation projects have many problems and risks, through the operation, construction, investment and other links. Based on the theoretical content of risk management in project management and combined with practical cases, this paper puts forward countermeasures and suggestions for important risks in the project, so as to analyze and discuss the risks of garbage incineration BOT project. Firstly, this paper investigates and collates the research situation of relevant projects at home and abroad, and systematically summarizes the project research results from three aspects, namely, BOT risk management of waste incineration power generation projects, BOT model of projects and BOT project risk research. Secondly, the multi-case study method was used to analyze the risks of 3 typical waste-to-power generation BOT projects, collect risk factors, construct risk aggregation, and summarize 5 types of key risks and 14 kinds of risks. Then, according to the BOT agreement signed with the government side, the specific risk management method is proposed. The goal of this study is the LF waste incineration power generation project. The author participated in the project and identified and evaluated the project risks through risk list and hierarchical analysis, so as to find out the main risks in the project such as government risk, public opinion risk, completion risk and operational risk. In addition, in combination with the project risk, specific risk coping strategies are proposed according to the risk coping strategies proposed in the paper and the actual situation of the project, so as to reduce the degree of project risk and reduce risk losses. For other similar projects in China, there is reference and reference significance and value.

Performance evaluation of trommel screens: A case study of a municipal solid waste treatment plant

The efficient and effective operation of trommel screens is essential for the economic and environmental sustainability of mechanical biological treatment (MBT) based solid waste treatment plants. The present study evaluated the performance of four trommel screens (aperture sizes of 80, 32, 16, and 4 mm) being used at the MBT plant of the Municipal Corporation Karnal, India. The performance of trommel screens was evaluated at a fixed speed of rotation and inclination angle. For optimum performance, trommel screens must be operated at a particular range of feed rates with regular cleaning every four hours of operation. The organic recovery achieved by 80 mm and 32 mm aperture size trommel screen was 26.95 % and 95.82 %. The organic quality improvement achieved by 80 mm and 32 mm trommel screens was 122.50 % and 108.89 %. The trommel screen's heating value improvement and energy recovery ranged from 70.68 % to 135.16 % and 28.27 % to 98.74 %, respectively. The oversized fractions of trommel screens of opening sizes 80 mm and 32 mm meet the fuel specification prescribed by the Indian Solid Waste Management Rules 2016. The trommel screen's Specific Energy Consumption (SEC) ranged from 0.63 kWh/tonne to 5.66 kWh/tonne. The learnings and outcomes of this study are helpful for designers, policymakers, operators of solid waste treatment plants, and researchers.

Spatial correlation network of municipal solid waste carbon emissions and its influencing factors in China

Clarifying the provincial spatial correlation network of municipal solid waste (MSW) carbon emissions and its influencing factors is significant for reducing MSW carbon emissions and for ensuring cross-regional coordinated emission reduction. This study used a modified gravity model and social network analysis to explore the structural characteristics of the spatial correlation network of MSW carbon emissions. The quadratic assignment procedure was then used to examine the influencing factors. The results are as follows: (1) From 2005 to 2020, the MSW carbon emissions spatial correlation network showed an intuitive and complex network structure. The tightness of the network increased with fluctuations but still needs improvement, while the network structure exhibited good accessibility and stability. (2) The spatial network exhibited a significant “core-edge” distribution, with Beijing, Tianjin, Shanghai, Jiangsu, Zhejiang, and Fujian being at the center of the spatial correlation network and playing leading roles. (3) The spatial correlation network of MSW carbon emissions was divided into four parts, with the four parts having few internal connections but with the relationships between them being close. (4) Geographical adjacency, economic development level, science and technology level, and MSW treatment structure significantly influenced spatial correlations, while the urbanization level and degree of government intervention had no significant influence on spatial correlations.

Use of municipal solid waste incineration (MSWI) bottom ash as a permeable subgrade material: An experimental and mechanism study

ABSTRACT As a traditional method of waste treatment, municipal solid waste incineration (MSWI) has become one of the main methods of urban waste treatment. However, as a byproduct of MSWI, a large amount of MSWI bottom ash is not reused in current practice. This study innovatively posits MSWI bottom ash as an eco-friendly adsorbent rather than a pollutant, exploring its potential application as a permeable subgrade material. The results reveal that MSWI bottom ash exhibits promising properties to serve as a permeable subgrade material to achieve the permeability and improve the sustainability for subgrade. Due to the arrangement of its particles, it shows excellent performance in shear strength and permeability, which are comparable to or surpass those of sandy soils. The average pore width of 14.200 nm allows heavy metal substances to be encapsulated within the matrix, significantly reducing their leachability, thereby aligning with environmental friendliness standards. Its adsorption capacity is about 6.60 mg/g, and the adsorption capacity per volume is 3.66 times and 2.04 times that of fly ash and clay, respectively. The mechanism analysis shows that the adsorption process is monolayer heterogeneous adsorption. This paper presents a novel perspective on reusing MSWI bottom ash and provides evidence supporting its effective utilization as a permeable subgrade material, offering substantial environmental benefits through enhanced adsorption ability. Implications: Municipal solid waste incineration (MSWI) is a common method for municipal solid waste treatment, while the MSWI bottom ash is often not reused. This paper explored the explores the feasibility of using MSWI bottom ash as a permeable road base material. The results show that the particle arrangement enables excellent shear strength and permeability, comparable to sandy soil. It meets safety requirements for the leaching of heavy metals and acts as an adsorbent for pollutants leaching from permeable pavements. Furthermore, the mechanisms underlying these behaviors of MSWI were confirmed by microstructural and mineralogical analyses. These indicate that MSWI bottom ash has great potential as a permeable road base material. This paper provides a clear understanding of the physical, mechanical and environmental properties of MSWI bottom ash, which can promote its reuse in practice.

Effect evaluation of different green wastes on food waste digestate composting and improvement of operational conditions.

This study attempted to determine the influence of diverse green wastes on food waste digestate composting and the improvement of operational conditions. Various effects of the green wastes (GW), with different types and sizes, initial substrate mixture C/N ratios, compost pile heights, and turning frequencies on the food waste digestate (FWD) composting were examined in the current work. The findings showed that the use of street sweeping green waste (SSGW) as an additive can maintain the thermophilic stage of the FWD composting for 28days, while the end-product contained the greatest amounts of total phosphorus (TP, 2.29%) and total potassium (TK, 4.61%) and the lowest moisture content (14.8%). Crushed SSGW (20mm) enabled the FWD composting to maintain the longest thermophilic period (28days), achieving the highest temperature (70.2°C) and seed germination index (GI, 100%). Adjusting the initial substrate mixture C/N ratio to 25, compost pile height to 30cm, and turning frequency to three times a day could enhance the efficiency and improve the fertilizer quality of the co-composting of the FWD and SSGW. This study suggested that co-composting of FWD and SSGW (FWD/SSGW = 2.3, wet weight) is a promising technique for the treatment of municipal solid waste and provided significant theoretical data for the application of composting.

Air quality impacts of landfill fires: A case study from the Brahmapuram Municipal Solid Waste Treatment Plant in Kochi, India

The occurrence of waste fires in unscientifically managed landfill sites has become a pressing environmental issue in the urban centers of developing economies. In the present work, an investigation was carried out to evaluate the air quality implications of three major fire events that occurred at the Brahmapuram Municipal Solid Waste Treatment Plant (BMSWTP) in Kochi, India. Initially, Landsat-based surface temperature monitoring was conducted to identify the thermal hotspots within the landfill. The emissions of different pollutants during waste fires were quantified and compared between satellite-based ex-situ and field-based in-situ methods. The dispersion patterns of PM2.5 particles released during the fires were visualised using the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) particle dispersion model. The Landfill Gas Emissions Model (LandGEM) was employed to quantify the greenhouse gases (GHGs) released during waste storage, which was then compared with the GHGs emissions during waste fires. In-situ emission estimates showed that the combustion of waste at BMSWTP led to the release of 909.3 MT of PM10, 938.8 MT of PM2.5, 5832.9 MT of CO, 43.6 MT of SOx, 284.2 MT of NOx, 138,941.9 MT of CO2, 426.8 MT of CH4, and 2665.1 MT of VOC. However, a noticeable disparity was observed between the in-situ and ex-situ emission estimates, wherein the latter underestimated the actual emissions. Most of the emitted PM2.5 particles propagated oceanward under the influence of prevailing winds, covering the densely populated areas of Kochi municipal corporation. The amount of CH4 and CO2 emitted during the waste fires was on par with the emissions from 159 days of waste storage for CH4 and 51.8 years of waste storage for CO2, with a cumulative global warming potential of 147.9 Gg CO2-e.

Effects of tube configurations on the heat transfer and hydrodynamic behavior in a gas-solid fluidized bed

The study of surface-to-bed heat transfer and flow characteristics in a gas-solid fluidized bed with different immersed tube configurations were investigated using the Eulerian-Eulerian method coupled with the kinetic theory of granular flow (KTGF) computationally. Compared with cases of in-line configurations, the staggered configurations increased the heat transfer coefficients (HTC) of the center-immersed heating tube. Moreover, it was found that with an increase in the rows and columns of the configurations, the HTCs increased and decreased respectively. The surface-to-bed heat transfer process was investigated combined with the particle renewal mechanism, and it was demonstrated that the HTCs were significantly affected by the surrounding packet fraction distribution and the packet residence time on the immersed heating surface. The results could be quantitatively employed to aid the heating tube configuration in designing the external heat exchanger (EHE) of a circulating fluidized bed (CFB) boiler for the treatment of municipal solid waste (MSW).

The effect of biological methods for MSW treatment on the physicochemical, microbiological and phytotoxic properties of used biofilter bed media

Biofilters are commonly used in municipal solid waste treatment (MSW) facilities to remove odors and pollutants from process gases. However, the effectiveness of biofilter bed media decreases over time, necessitating periodic replacement. The type of the treatment process may affect the lifespan of the bed and the way it should be utilized after replacement. This study aimed to analyze the physical, chemical, calorific, microbiological, and phytotoxic parameters of bed media in biofilters operated at an industrial scale in MSW treatment plants. The experiments included three full cycles of biofiltering gases from biodrying, composting, and aerobic biostabilization in two variations. Physicochemical properties (moisture, organic matter, carbon, nitrogen, sulfur, heavy metal contents), respiration activity (AT4), phytotoxicity, and microorganism abundance were determined for initial materials and samples from two biofilter layers collected after each cycle. Results revealed a substantial reduction in AT4 (by 63%-87% compared to initial material), significant moisture content increase in the bottom layers (by 61% or more, depending on the process), and a considerable decrease in microorganism abundance. Biofilter bed media from biodrying and composting exhibited low environmental risk (low heavy metal concentrations, negligible phytotoxicity, and microbiological stability). However, bed packings from aerobic biostabilization processes showed significant inhibition of indicator plants and incomplete sanitization (presence of pathogens like E. coli and Salmonella spp.). Therefore, these bed packings can be utilized for energy recovery, such as incineration after drying. This research provides significant insights into the effectiveness and safety of biofilter bed media in MSW treatment plants.

Research progress and perspectives of biogas production from municipal organic solid waste

Abstract Anaerobic digestion is a prevailing technology for the treatment and utilization of municipal organic solid waste (MOSW). In this technology, the macromolecular organic matter in waste degrades into small molecular substances through the anaerobic decomposition of microorganisms, producing biogas that can provide enormous energy. This paper focuses on the research progress of anaerobic digestion of various organic wastes for biogas production. The principle and process of anaerobic digestion for biogas production are introduced, along with the key factors affecting anaerobic digestion efficiency, such as temperature, pH, and sealing conditions. At the same time, the current cycle treatment technology and comprehensive treatment system of MOSW are also summarized. Furthermore, the paper explores biogas purification technologies, including desulfurization, deoxidation, drying, and decarbonization. Finally, the state-of-the-art of the utilization of MOSW for biogas production in the world and the problems faced by the utilization of MOSW for biogas production in China are reviewed. By summarizing the anaerobic digestion technology of MOSW, this review hopes to provide some reasonable solutions for the high-value utilization of MOSW.

Novel energy recovery from an integrated municipal solid waste and leachate treatment system

Novel energy recovery from an integrated municipal solid waste and leachate treatment system

Study on the interaction between inherent minerals of coal with refuse derived fuel (RDF) during co-firing

In this paper, refuse derived fuel (RDF) and bituminous coal were co-fired to investigate the particulate matter (PM) yields and the interaction between the inherit minerals in a lab-scale drop tube furnace (DTF). The PM1-10 yields during the co-firing of coal and RDF dramatically decreased by 16.29 %∼28.5 % of the combustion of coal alone. In addition, methane auxiliary combustion inhibited the PM1 yields by 7.95 % at air atmosphere. The Si-rich minerals in coal interreacted with the organic alkali (earth) metals in RDF, massively generating sticky particles with high liquid amount of K-Al-Si and Ca-Al-Si, promoting the transformation of fine grains into coarser mode. Moreover, it was proved that both methane auxiliary combustion and co-firing can reduce the emission of fine particles. The additional heat accelerated the burn of the char at the early stage of combustion, providing adequate time for the interaction between the inorganic species. Through thermodynamic equilibrium calculations of 1500 ∼ 3000 fly ash grains, it was found that co-firing increased the formation of sticky particles by 64.8 %∼70.3 %, resulting in a significant enhancement in capturing fine particles and Na, K vapor. Therefore, the co-firing of coal with RDF offers a promising approach to realize the harmless and resourceful treatment of municipal solid waste (MSW), and inhibit land resource losses caused by landfill

Developing an Effcient Framework and Mathematical Modelling for Municipal Solid Waste Management in India

An increase in municipal waste has become one of the biggest problems today. Managing waste is a big challenge for every country. Municipal waste management includes transportation and recycling of waste, which needs huge funds. Moreover, significant carbon emissions occur while transporting garbage from one site to another. Thus, this study focuses on reducing the cost due to municipal solid waste (MSW) transportation. The research aims to develop a mathematical model of the supply chain of MSW management. The process of segregation and recycling is also considered in this study. We consider six Indian states and identify the dumping location of the garbage. The study proposes an efficient framework for selecting the segregation hub location and location of MSW treatment plants. The outcomes would be beneficial to achieve an efficient waste management strategy with reduced cost. The numerical simulation results of the model provides the minimum transportation cost as Rs. 4.92 × 106 according to the locations selected for the study. The final strategic decisions is feasible under the constraint sets considered in the model.

The Treatment of Municipal Solid Waste in Cambodia, Thailand and Vietnam: An Environmental and Technological Analysis of Current and Future Scenarios

The population growth of South-Asian countries is contributing significantly to the escalating volume of municipal solid waste (MSW). Presently, waste management in this region predominantly relies on landfilling, necessitating a shift towards a more sustainable paradigm. To address this imperative, this study explores the feasibility of extending the European-based waste management system for treating MSW in Cambodia, Thailand, and Vietnam. Assuming as current scenario the direct disposal in landfill, the environmental and technical performances of five other proposed scenarios based on the following technologies were assessed: mechanical–biological treatment; incineration; their combination; mechanical recycling; composting and anaerobic digestion. As expected, all alternative technologies showed potential for improving the current scenario. However, from an environmental point of view, incineration of mixed MSW emerged as the sole option that yielded a discernible environmental benefit for all the countries involved in the study (achieving a carbon footprint of about −0.111 t-CO2-Eq./FU). Recycling-based scenarios achieved higher benefits for Thailand and Vietnam (−0.145 and −0.186 t-CO2-Eq./FU, respectively), but not Cambodia (0.072 t-CO2-Eq./FU) due to the lack of valuable materials to recycle. Technical findings showed how separate collection remains the system generating the least amount of waste for disposal (about 0.185 t), having a synergic effect on the combined approach of mechanical–biological treatment and incineration, which boasts the highest specific energy yield (about 0.339 and 1.183 kW/t, for electric and thermal energy, respectively). These results underscore the imperative to extend the analysis to the economic domain, combining diverse criteria to identify the most sustainable solution.

Prediction of municipal solid waste treatment and disposal in high cold and high altitude area based on system dynamics: a case study of Lhasa

At present, the high cold and high altitude areas of China continue to face challenges in achieving high rates of resource utilization for the municipal solid waste (MSW). In this paper, for the first time, a prediction method based on system dynamics (SD) for the treatment and disposal of municipal solid waste in high cold and high altitude areas is proposed and applied to Lhasa City. The model simulate and predict the proportion of treatment methods (including landfill, incineration, kitchen waste disposal, recycling) and the rate of resource utilization (other disposal methods except landfill) of municipal solid waste under Natural Tendency and regulation schemes (Strengthened Municipal Solid Waste Classification Scheme and Municipal Solid Waste Classification and Treatment Scheme). The results show that strengthening municipal solid waste classification and treatment can significantly enhance the resource utilization rate of municipal solid waste in Lhasa, with an expected rate of 100% by 2026. This outcome has the potential to promote sustainable and healthy development of society, economy and environment of a city.

Possibilities of using ash from thermal treatment of municipal solid waste in hardening slurries

Possibilities of using ash from thermal treatment of municipal solid waste in hardening slurries