Municipal Solid Waste Research Articles

Mathematical analysis of an anaerobic digestion model for biogas production from solid waste.

Municipal solid waste is one of the most significant sources of gas emissions. In a context of renewable energy production and greenhouse gas emission reduction, we focus on the amount of biogas produced by the anaerobic digestion of organic matter in a controlled landfill environment. We present a mathematical model describing this process from a microbiological and biochemical point of view, including the dynamics of the methane and carbon dioxide produced. A qualitative analysis of the dynamic system shows the existence of an infinite number of non-hyperbolic equilibria inducing an attractor that has been identified. Through numerical tests, we explore how the non-connectivity of the attractor resulting from the choice of growth functions can entirely transform the performance of the process, and highlight critical initial stock values that influence the amount of biogas produced.

Green governance and the EKC hypothesis: Evidence from Vietnamese provinces

The Environmental Kuznets Curve (EKC) posits an inverted U-shaped relationship between environmental degradation and economic development, suggesting that while economic growth may initially harm the environment, it can ultimately lead to both economic and environmental benefits in the long run. Empirical evidence of this hypothesis strongly supports the Sustainable Development Goals (SDGs) such as SDG 1 (No Poverty), SDG 8 (Good Jobs and Economic Growth), and SDG 11 (Sustainable Cities and Communities). While the EKC literature focused more on national or cross-country analyses, limited studies examined this hypothesis at the regional or provincial level and often used data from the U.S. and China. This study revisits the EKC hypothesis in Vietnamese provinces by examining municipal solid waste (MSW), which is important to the SDGs but has attracted less attention compared to other pollutants. The role of green governance, measured via the provincial green index (PGI), is also examined. Findings indicate that the EKC exists at the provincial level in Vietnam, with the PGI reducing the GDP requirement for the EKC turning point, thereby accelerating environmental improvements. Consequently, promoting green governance is important for emerging countries such as Vietnam to achieve sustainable development and the SDGs.

Numerical simulation and intelligent prediction of a 500 t/d municipal solid waste incinerator

After classifying municipal solid waste (MSW), understanding how changes in its characteristics affect the incineration process becomes essential. Optimizing and adjusting operating parameters is crucial to ensure the smooth operation of MSW incinerators. In this study, we developed a three-dimensional numerical simulation model for a 500 t/d MSW incinerator, based on a two-fluid model that accounts for grate motion. We examined the effects of load and moisture on the combustion process. Using the results from the numerical simulation and on-site operational data, we established a machine learning model to predict incinerator conditions based on load, waste particle size, and moisture content. The average relative errors for the training and test sets were approximately 0.33 % and 0.44 %, respectively. Finally, we compared the influence of different operating parameters on flue gas temperature. Our numerical simulation model and intelligent prediction method offer valuable guidance for optimizing existing MSW incinerators and designing new ones.

Assessing the Environmental Impact of Municipal Waste on Energy Incineration Technology for Power Generation Using Life Cycle Assessment Methodology

The life cycle assessment methodology is a comprehensive environmental impact evaluation approach rooted in the “cradle-to-grave” concept. This study takes a municipal solid waste incineration power plant in central China as an example to comprehensively explore the potential ecological and environmental impacts of municipal solid waste incineration power generation through life cycle assessment methods. Burning one ton of waste can recover 7342 joules of thermal energy. Compared with traditional landfill, incineration can reduce greenhouse gas emissions by about 30%, with a potential global warming impact of −0.69 kg of carbon dioxide equivalent. Amongst environmental impacts, land, freshwater, and marine ecosystems possess the greatest potential toxicity, followed by the harmful effects on human health and the influence of ozone-producing photochemical pollution. Lastly, there comes terrestrial acidification, whereas other types of effects can be relatively disregarded in comparison. In the process of waste incineration power generation, the potential impacts of global warming, ionizing radiation, and fossil resource scarcity are less than zero, indicating that this is an environmentally friendly process. In response to the above-mentioned environmental impacts, it is necessary to pay attention to improving incineration efficiency, optimizing leachate treatment, reducing coal use, and controlling acidic gas emissions in the process of urban solid waste incineration power generation. This research offers insights into advancing environmentally sustainable technologies for utilizing waste as an energy resource.

Circular Economy: Municipal Solid Waste and Landfilling Analyses in Slovakia

The pursuit of shifting Slovakia towards a circular economy is met with a multitude of obstacles, including the pervasive consumerist mindset among Slovakians. This mindset favors packaged food, leading to its improper disposal in municipal waste instead of being recycled. Furthermore, the inclination towards landfills poses a significant challenge in the management of municipal solid waste (MSW). To address this issue, a quantitative analysis was conducted using developed and validated models, incorporating various factors related to MSW management in Slovakia. Our study confirmed the significance of parameters such as MSW management costs and population size in the amount of MSW generated. Furthermore, our findings include a short-term forecast for MSW generation in Slovakia for the next two years. These results, based on quantitative data, provide valuable insights for policymakers and waste management authorities in Slovakia, emphasizing the urgent need for a transition towards a more sustainable and circular economy.

Remanufacturing construction and demolition waste and incineration ashes into eco-blocks: Quantitative sustainability assessment

This study performed a sustainability evaluation of a proposed business for remanufacturing concrete materials from construction and demolition waste (CDW) and ash from the combustion of municipal solid waste (MSW) to produce eco-blocks for construction applications. Six possible industrial remanufacturing alternatives are proposed based on commercially available industrial machinery and their economic sustainability was compared by a cost and profit feasibility study. Furthermore, the technical feasibility was evaluated by considering the maturity of the selected machinery based on the relationships among the cost–productivity, power–productivity, and number of workers–productivity pairs. The proposed remanufacturing business achieves a maximum profit of 17,643 USD/day with a minimum remanufacturing cost of 30.65 USD/t for the production of 529 t of eco-blocks in an 8-h factory shift. A quantitative environmental sustainability assessment was performed using the remanufacturing cost, profit, concrete savings, energy savings, CO2 emission savings, and eco-cost savings as criteria based on demographic statistics from the literature for current and predicted CDW and MSW generation. CDW and incineration ash are widely available, so the proposed process is viable worldwide. Based on the technical, economic, and environmental sustainability results, a final sustainability index of 0.874 was calculated, which exceeds literature thresholds for a sustainable business, indicating that the proposed eco-block remanufacturing process has the potential to generate substantial profits, while positively contributing to reducing waste and energy usage by recovering valuable resources and producing value-added products. The remanufactured eco-blocks are prepared in the same way as typical concrete blocks and can be used for all of the same residential, commercial, and industrial construction and landscaping applications. The remanufactured eco-blocks have several advantages over typical concrete blocks, including a much lower manufacturing cost (∼50 % lower), significant environmental and resource savings by avoiding the use of new sand and gravel resources, and improved mechanical properties.

Household Solid Waste Management and Environmental Impacts in the Ibadan Metropolis, Nigeria

Given the current rate of urbanization, municipalities in most Nigerian cities have struggled with the collection, transportation, and disposal of solid waste. This is due to waste generation, both residential and commercial, occurring in a dispersed manner across homes, buildings, streets, parks, and even vacant spaces within communities. This manuscript aims to evaluate the state of municipal solid waste management in Ibadan, household solid waste storage practices, and the locations of solid waste storage containers (skip points) in relation to accessibility and health risks to the community, in accordance with Nigerian National Solid Waste Management Standards and other pertinent international standards. A structured questionnaire was distributed to 21 micro and small firms and 250 homes in each of the three local government areas of the metropolis, with descriptive statistics used to interpret the data. According to the study results, inadequate Municipal Solid Waste Management (MSWM) service delivery in the Ibadan metropolitan area can be attributed to several issues, including a lack of institutional coordination among urban planners. The study’s conclusions indicate that the state of MSWM in the sampled areas is either inadequate or has poor spatial coverage and container utilization. Lastly, the study primarily suggests that these measures can reduce problems associated with MSWM by encouraging public-private partnerships, fostering effective institutional coordination with urban planner consultants in MSWM and skip-point location, and motivating the community to adopt integrated sustainable Solid Waste Management (SWM) strategies.

Effect of the spatial changes in engineering properties on municipal solid waste landfill slope stability

Effect of the spatial changes in engineering properties on municipal solid waste landfill slope stability

Analysis of physicochemical characteristics of municipal solid waste in Hung Yen city

Analysis of physicochemical characteristics of municipal solid waste in Hung Yen city

Current status and trend of municipal solid waste management in the Mekong delta

Current status and trend of municipal solid waste management in the Mekong delta

Enabling sustainable circular economy in Indian municipal solid waste management system: an ISM and fuzzy MICMAC approach

PurposeMismanagement of municipal solid waste (MSW) has led to resource depletion, ecosystem degradation and socio-economic risks, emphasizing the necessity to promote sustainable circular economy (SuCE) practices. This article identifies relevant enablers and unveils their interconnected roles in facilitating a municipal solid waste management (MSWM) system aligned with the principles of SuCE.Design/methodology/approachTo identify pertinent enablers for MSWM systems based on SuCE principles, the study conducted a literature review and engaged experts from waste management sectors and academia to consolidate the final list of enablers. Following this, the study investigated the inter-relationships among these enablers using both Interpretive Structural Modeling (ISM) integrated and fuzzy Matrix Impact Cross-Reference Multiplication Applied to a Classification (fuzzy MICMAC) with MATLAB.FindingsThe study identified a comprehensive set of 23 enablers and categorized them into four control measures instrumental for the effective integration of SuCE principles in the context of the Indian MSWM system. Notably, the analysis highlighted that “authoritative pressure” and “policy transformation” are the highly influential enablers.Practical implicationsThe study emphasizes actionable implications for stakeholders in the Indian MSWM sector. Policymakers and governmental bodies can enforce “authoritative pressure,” “policy transformation” and “budget allocation”. Meanwhile, managers can focus on “promotion of SuCE awareness”, “formalizing the informal workforce”, “infrastructure modernization”, “stakeholder engagement and alignment”, “segregation strategy”, “disruption preparedness”, and “local-based strategy”.Originality/valueThis study proposed a unique ISM diagraph and cluster of enablers to enhance the novelty of the study.

Energy and nutrient recovery from municipal and industrial waste and wastewater - a perspective.

This publication highlights the latest advancements in the field of energy and nutrient recovery from organics rich municipal and industrial waste and wastewater. Energy and carbon rich waste streams are multifaceted, including municipal solid waste, industrial waste, agricultural by-products and residues, beached or residual seaweed biomass from post-harvest processing, and food waste and are valuable resources to overcome current limitations with sustainable feedstock supply chains for biorefining approaches. The emphasis will be on the most recent scientific progress in the area, including the development of new and innovative technologies, such as microbial processes and the role of biofilms for the degradation of organic pollutants in wastewater, as well as the production of biofuels and value-added products from organic waste and wastewater streams. The carboxylate platform, which employs microbiomes to produce mixed carboxylic acids through methane-arrested anaerobic digestion, is the focus as a new conversion technology. Nutrient recycling from conventional waste streams such as wastewater and digestate, and the energetic valorization of such streams will also be discussed. The selected technologies significantly contribute to advanced waste and wastewater treatment and support the recovery and utilization of carboxylic acids as the basis to produce many useful and valuable products, including food and feed preservatives, human and animal health supplements, solvents, plasticizers, lubricants, and even biofuels such as sustainable aviation fuel.

Optimizing refuse-derived fuel production: a review of pre-treatment techniques for municipal solid waste reclamation

Optimizing refuse-derived fuel production: a review of pre-treatment techniques for municipal solid waste reclamation

Research on the Preparation of Dry Mixed Mortar Using Waste Incineration Fly Ash

This study investigated the effect of water-washed municipal solid waste incineration fly ash (MSWI FA) as an admixture on the performance of dry mixed mortar and used X-ray diffraction (XRD) and scanning electron microscope (SEM) detection methods to conduct microscopic analysis. The experiment investigated the effects of the amount and water content of washed municipal solid waste incineration fly ash, cement, additives, sand and gravel, and curing time on the compressive flexural strength of dry mixed mortar at 28 days. The results show that when the content of water-washed MSWI FA is 9.80%, the content of sand and gravel is 73.50%, the content of ordinary Portland cement (PO42.5) is 16.66%, the content of water-reducing agent is 1.47‰, the content of cellulose is 0.03‰, the content of the expansion agent is 0.49‰, the addition of water is 130–160 mL/kg, the consistency of the sample can reach 91.8 mm, and the water retention rate can reach 93.6%. The flexural strength of the sample at 28 days can reach 7.5 MPa, and the compressive strength at 28 days can reach 28.30 MPa. Metal ions, such as Pb2+ and Gd2+ in MSWI FA, under the combined action of silicate cement in dry mixed mortar and fibers in cellulose, crisscross and form a solidified material, which will not be leached out. This quality meets the requirements of dry mixed mortar for ordinary plastering and masonry mortar (GB-T 25181-2019), and the leaching toxicity of the sample meets the “Identification Standard for Hazardous Waste” (GB5085.3-2007). This work provides a meaningful exploration of the resource utilization of water-washed MSWI FA.

Effects of Biochar on Arsenic-Contaminated Soil: Chemical Fractionation, Vegetation Growth, and Oral Bioaccessibility.

Contamination by arsenic (As) is a pressing environmental and public health issue requiring urgent remediation strategies. One cost-effective and eco-friendly method involves adding stabilizing agents to soils to reduce As mobility. However, remediation projects must also address potential ecotoxicological effects. These effects may include harmful impacts on both aquatic and terrestrial organisms, including plants, disruption of ecosystem balance, and the potential bioaccumulation of toxic substances in the food chain. Biochar from organic fraction of municipal solid waste (OFMSW) shows promise for As-contaminated soil remediation. Pot experiments were conducted with soil contaminated with As (100 mg kg-1) and amended with biochar produced at three different temperatures (300, 500, and 700 °C) and addition rates (1 and 5%, w/w). Chemical fractionation showed higher As concentration in a less accessible fraction (F4). Biochar amendments did not significantly differ from the control in As immobilization, but enhanced maize (Zea mays) growth and reduced As uptake, with the most promising results seen with 1% of biochar produced at 700 °C. The bioaccumulation factor (BCF) and translocation factor (TF) were both lower than 1, indicating a low absorption of As and minimal translocation from the root to the shoot. The bioaccessible percentage was higher in the samples treated with biochar compared to the control. According to the results, biochar showed no satisfactory potential for As immobilization and its approach of pretreatment/modification should be tested regarding possible improvements in the immobilization performance of As. Since most contaminations involve multiple contaminants simultaneously, it is essential to test the interactions between arsenic and other pollutants to understand the effects of biochar in such complex scenarios, which will be explored in future studies. Graphical abstract.

Optimizing municipal solid waste collection management through data mining: a case study in southern Brazil

Optimizing municipal solid waste collection management through data mining: a case study in southern Brazil

Construction of a new emergency management system for potentially viral/viral municipal solid waste in China: Based on the "Beam-Column Structure" framework model

Emergency management of municipal solid waste during public health emergencies is crucial for curbing the spread of viruses and controlling environmental pollution. Most existing solid waste management systems, are designed with a top-down approach, covering multiple industries and sectors. However, these systems often fail to effectively manage potentially viral solid waste in household waste, which impedes effective solid waste management during public health emergencies and increases the risk of viral outbreaks. For example, during the COVID-19 outbreak, negligent management of potentially viral solid waste may result in the formation of a potential transmission chain of COVID-19 virus. Improper waste management may contaminate natural vectors such as water, soil and air, thereby increasing the pathways of human contact with infected vectors and promoting the risk of transmission of viral diseases such as dengue, Zika and hepatitis A. In this study, the applicability and limitations of the Chinese public emergency management system in the disposal of Potentially Viral/Viral Municipal Solid Waste (PVMSW) were analyzed in the breakout of public health crises. To address the need for precise risk control, efficient collaboration among key stakeholders, functional integration crossing multiple management organizations and flexible responses to complex situations, we proposed a PVMSW emergency management system based on a “Beam-Column Structure” model. This system consists of four modules: main traction, organizational leadership, functional articulation and demand matching. Each module is supported by the corresponding safeguards, including multi-level subject responsibilities, multi-scenario organization and implementation, multi-chain process connection and multi-demand control methods. The PVMSW emergency management system proposed in this study contributes to extending the framework of existing waste management protocols and enhancing the timely collection, transportation and disposal of PVMSW in public health crises. It offers valuable insights and guidance on the practices for improving risk awareness and management capacity in China's solid waste emergency response.

Modeling of methane emissions from waste disposal sites at selected Egyptian governorates and potential energy production from waste-to-energy projects

Waste and energy sectors have significant contributions to the greenhouse gas (GHG) emissions caused primarily by the population expansion. Waste-to-Energy (WtE) is introduced to address the issue raised by both sectors simultaneously through utilization of the potential energy stored in municipal solid waste (MSW) as well as offsetting GHG emissions. Limited research have been conducted in Egypt to assess the current situation of MSW management and associated methane emissions. The current study focused on estimating the baseline methane emissions for six Egyptian governorates and determining the energy production potential from WtE projects. To achieve this aim, three scenarios have been assessed: Baseline, Landfill Gas to Energy (LFGE), and Incineration scenarios. Key results revealed that a total of 3.7 million tonnes of methane would be emitted from all studied governorates generated over 50 years. Incineration also found to be more favorable in all governorates in terms of energy production, quantity of avoided GHG emissions, and in terms of economic viability over LFGE. Implementing incineration in all governorates would generate about 5.6 TWh energy annually and could avoid about 5 Mt CO2 eq annually in comparison to LFGE that would generate about 0.6 TWh annually and could avoid about 2.5 Mt CO2 eq annually. In terms of economic viability of WtE projects, while they were generally not economically viable under the assumptions made in the current study, incineration technology deemed promising, but policy adjustments, such as competitive Feed-in Tariff (FiT) rates and the inclusion of gate fees, are necessary. Specific minimum gate fees and FiT were identified for each governorate, providing essential guidance for decision makers to ensure the viability of WtE implementation. This study would support the decision makers in assessing technically and financially feasible options for WtE technologies in the selected governorates.

Quantification and characterization of municipal solid waste at aler dumpsite, Lira City, Uganda: Assessing pollution levels and health risks

Managing municipal solid waste (MSW) in urban areas of developing countries is a significant challenge due to rapid urbanization and inadequate infrastructure. This study aims to quantify the MSW at Aler dumpsite in Lira City, Uganda, and assess the associated environmental and health risks. Our findings revealed a daily dumping rate of 7.38 tons, predominantly organic waste. Leachate from the site exceeded WHO limits for nutrients and heavy metals, with exceptionally high amounts of cadmium (Cd) found in soil (4.8 mg/kg) and vegetables. The water quality in nearby streams was poor, rendering it unfit for consumption due to elevated ion and nutrient levels. Health risk assessments indicated significant non-carcinogenic risks from heavy metal ingestion, with a hazard index (HI) of 4.6 for adults and 9.6 for children. While dermal exposure risks were generally low, children were at risk from stream 1 (HQderm = 1.165). Vegetable analysis revealed levels of lead (Pb), cadmium (Cd), zinc (Zn), and nickel (Ni) above safe doses, posing significant non-carcinogenic risks. To address these issues, we recommend increasing public awareness to avoid consuming water and vegetables from areas around the dump site. Additionally, we suggest that the responsible authorities improve MSW management by constructing sanitary landfills to minimize water, soil, and plant pollution from landfill leachate.

Efficient fluoride recovery from wastewater using mesoporous Ca-based nanomaterials derived from municipal solid waste incineration fly ash via fluidized bed crystallization

This study introduces an innovative approach utilizing mesoporous Ca-based nanomaterial (MCN) derived from municipal solid waste incineration (MSWI) fly ash as carriers in a fluidized bed crystallization (FBC) process for the recovery of fluoride from semiconductor wastewater. The transformation of nonporous MSWI fly ash into mesoporous structures was achieved through facile treatments, including ultrasonic-assisted leaching with ethylenediaminetetraacetic acid disodium salt dihydrate (EDTA–Na) and surface modification with sodium silicate, enhancing surface functionalities and active site formation. The resulting MCN exhibited a significant surface area of 222.0 m2/g, ideal for fluoride recovery. When tested with synthetic wastewater, the recovery efficiency and crystallization ratio of fluoride using MCN in the FBC system reached 99.0 % and 93.3 %, respectively. Further investigation revealed that the unique surface properties and large surface area of the MCN promoted the crystallization of fluoride-containing precipitates, resulting in homogeneously nucleated cubic CaF2 crystals and facilitating layer-by-layer crystal growth. Testing the FBC process with real semiconductor wastewater resulted in a crystallization efficiency of 94.5 %, with the CaF2 content in the recovered precipitates reaching 84.3±0.7 %. These findings highlight the potential of MCN as an innovative carrier for fluoride recovery, demonstrating a novel and environmentally friendly method for converting waste into valuable materials. This study offers a promising solution for treating fluoride-contaminated wastewater, with high potential to revolutionize industrial wastewater management and promote a circular economy.