Municipal Waste Treatment Research Articles

The dynamics and assembly patterns of airborne pathogen communities in the municipal food waste treatment system and its risk implications

The dynamics and assembly patterns of airborne pathogen communities in the municipal food waste treatment system and its risk implications

Municipal Waste Treatment: Climate Change Mitigation Impacts and Carbon Credit Market Effects

Objective: Analyze the feasibility of proposing a comprehensive methodology for inventorying greenhouse gas (GHG) emissions from urban waste, with the goal of enhancing the attractiveness of carbon credits and demonstrating their impacts on climate mitigation. Theoretical Framework: The research is grounded in theories related to climate change, the circular economy, and urban waste management. Global warming is discussed through the works of authors such as David Wallace-Wells and José Goldemberg, alongside concepts from the GHG Protocol and Life Cycle Assessment (LCA). Method: The methodology involves a bibliographic review, document analysis, and exploratory research using secondary and qualitative data. Scientific articles and documents from organizations such as the IPCC and EMBRAPA, among other academic sources, were utilized. Results and Discussion: The research emphasizes that proper management of urban waste, aligned with the principles of the circular economy, can substantially reduce GHG emissions. "Zero Waste" projects are analyzed as viable alternatives for mitigating emissions and obtaining carbon credits. The Life Cycle Assessment (LCA) of products is identified as crucial for inventorying emissions across various stages of the life cycle, thereby facilitating the certification process for carbon credits. Research Implications: The proposed methodology can encourage new investments in recycling and waste reuse, as well as support the establishment of waste treatment units that maximize resource recovery and minimize environmental impacts.Originality: This study contributes to the literature by presenting an innovative approach to the management of urban waste and carbon credits, highlighting the importance of LCA in certifying reduced emissions. Originality: This study contributes to the existing literature by introducing an innovative approach to urban waste management and carbon credits, underscoring the importance of LCA in the certification of reduced emissions.

Carbon footprint impact of waste sorting on the municipal household waste treatment system: A community case study of Hangzhou

Considering the pressing need to reduce carbon emissions, the environmental impacts of waste sorting and its influencing factors remain unverified across many practical scenarios. This study focused on separating perishable and residual waste in a community in Hangzhou, China, examining how waste sorting behavior affects the carbon footprint of subsequent waste treatment systems through a randomized tracking survey and life cycle assessment (LCA) method. The results indicated that the sorted waste treatment system could achieve net carbon emissions ranging from −139.92 to −254.03 kg CO2 eq per day by integrating the anaerobic digestion of sorted perishable waste with the incineration of residual waste. In comparison to the conventional mixed incineration system, which had net carbon emissions between −56.37 and −115.46 kg CO2 eq per day and generated 383 kWh/t of power, the carbon reduction benefits of the sorted system were considerably greater, by a factor of 2.2–2.5. Additionally, the average amount of recovered electrical energy (993 kWh/t) was also higher by a factor of 2.6. Therefore, source separation of waste significantly enhances energy recovery and carbon reduction in household waste treatment systems. In this research system, incineration power generation and oil recovery serve as the primary units for reducing carbon emissions, and the proportion of residual waste generated greatly influences the total carbon emissions of the sorted waste treatment system (p < 0.05). Consequently, increasing the percentage of classified residual waste and optimizing machine efficiency will increase the carbon reduction benefits of waste sorting and treatment systems. These findings provide crucial references and guidance for advancing carbon reduction and waste classification in municipal solid waste (MSW) management systems.

Detecting and sourcing GHGs and atmospheric trace gases in a municipal waste treatment plant using coupled chemistry and isotope compositions

Landfill operations and waste processing facilities are important and highly heterogeneous sources of both greenhouse gases (GHGs) and non-GHG air pollutants in the atmosphere. This arises the need for detailed apportionment of waste sources in order to locate and subsequently reduce emissions from landfills. Here, a time series of in situ measurements of atmospheric trace gases and spatial allocation of specific emission source types under different processing phases and environmental conditions were conducted in and in the surroundings of a Municipal Solid Waste Treatment Plant (MSWTP) in south-western Poland. Results revealed that several individual GHG sources dominated across the waste processing facility and that GHGs concentrations displayed spatial seasonality. An increase in the ground-level CH4 concentrations, from ∼ 30.3 to 56.3 ppmv, was observed close (∼5 – 10 m) to the major emission sources within the MSWTP. While hotspot areas generally yielded elevated CH4 concentrations near the soil surface, these were relatively low (2.4 to 8.9 ppmv) along the facility’s fence line. The study of the corresponding δ13C delineated the extent of dispersion plumes downwind emission hotspots, characterized by a 13C depletion (around 4.0 ‰) in the atmospheric CH4 and CO2. For CH4, emissions were isotopically discriminated between the extraction wells at active quarters/cells (δ13C = –58.3 ± 1.1 ‰) and biogas produced in the biological waste treatment installation (δ13C = –62.7 ± 0.7 ‰). Most of the trace compounds (non-methane hydrocarbons, halocarbons, oxygen-bearing organic gases, ketones, nitrogenous and sulphurous gases, and other admixture compounds) detected at the ground surface were linked to the CH4- and CO2-rich spots. Despite the relatively high variability in the concentrations of organic and inorganic compounds observed at the MSWTP active zones, our results suggest that they do not have a meaningful impact on the surrounding air quality.

Practising urban agriculture positively influences household organic waste management habits: A quantitative study from Florianópolis, Brazil.

Proper household organic waste management practices are crucial to limit the negative environmental and health impacts that can result from inappropriate municipal waste treatment. The environmental impacts of organic waste have previously been described in the literature, and the main treatment strategy for managing such waste relies on technical facilities such as biodigesters. However, such technologies require significant financial investments, which could hinder their application in areas with lower economic power. Among the several available organic waste treatment strategies, composting for urban agricultural (UA) use has become increasingly popular. Although the literature suggests that UA can contribute to organic waste management by encouraging self-treatment practices, investigations into how practising UA can influence household waste management behaviours have been limited thus far. To this end, we analyse the role of practising UA along with other demographic variables, such as age, gender, education, income and housing conditions, in influencing citizens' household organic waste management behaviours. The city of Florianópolis, Brazil was selected as a case study since that municipality recently passed a new organic waste regulation law that supports the use of organic compost in UA. We surveyed 206 individuals regarding their household organic waste management habits in four behavioural areas: (i) separation, (ii) use of public services, (iii) self-treatment and (iv) reduction. The dataset comprises 102 individuals who were actively engaged in UA activities and 104 who were not involved in UA to compare habits of the two groups. The results show that UA practitioners are more likely to separate and self-treat their organic waste and use the derived compost for gardening activities. The use of public facilities for organic waste management is influenced by people's housing conditions. Respondents who lived in an apartment with no access to a garden logically had a lower willingness than did those with garden access to self-treat the organic waste produced. On the other hand, the results show that UA practitioners compost their own organic waste regardless of their housing conditions. The results show a strong, positive influence of practising UA on self-composting and thereby highlight the role of such practices in sensitizing urban residents to waste management issues and supporting local organic waste management strategies. Although the debate over the role of UA in organic waste management is still open, we reveal that highlighting this role could support a shift towards a circular approach to organic waste treatment.

Assessing the Economic and Environmental Impacts of Anaerobic Digestion for Municipal Organic Waste: A Case Study of Minamisanriku Town, Japan

Anaerobic digestion (AD), or biogas technology, is an optimal method for municipal organic waste (MOW) treatment, recovering both material and energy. This study takes a life cycle assessment perspective and examines the economic and environmental impacts of a BIO facility in Minamisanriku Town, Japan, which has utilized MOW (kitchen/food waste and surplus sludge from sewage) as local biomass resources since 2012. Stakeholder interviews were conducted to gather data on material flows and impacts. Scenario analysis considered various conditions, such as pre- and post-operation of the BIO facility, the use and non-use of digestate as liquid fertilizer, and the facility’s 100% operational efficiency. The results indicate that full operation of the BIO facility and marketing of value-added products, such as branded rice grown using liquid fertilizer, could significantly reduce greenhouse gas (GHG) emissions, lower integrated environmental costs, improve the regional economy, and increase net income. In the business as usual (BAU) scenario with a 56% operation rate of the BIO facility, there is an over 10% improvement in economic and environmental impacts compared to the pre-operation baseline. This study underscores the importance of maximizing biomass utilization to develop value-added uses by enhancing, extending, and expending stakeholder collaboration.

Compressed stabilised earth block synergistically valorising municipal solid waste incinerator bottom ash and sisal fiber: Strength, durability and life cycle analysis

Compressed stabilized earth blocks (CSEB) represent an eco-friendly substitute for traditional building materials, predominantly utilizing earth. Municipal Solid Waste Incineration Bottom Ash (MSWIBA) is a by-product of municipal waste treatment that can be creatively repurposed in construction projects. This research explores integrating MSWIBA as a substitute for Earth in CSEB production to conserve natural resources and repurpose waste, potentially reducing its landfill disposal. The sisal fibers (SF), often regarded as by-products of agricultural processes, offer an intriguing research material. The SF was treated with a 5 % NaOH alkaline solution to improve the CSEB bonding, increasing the flexural strength. The study aims to determine the optimal mix of stabilizers, in addition to a 10 % cement content, using various percentages of MSWIBA (10–40 % by weight of dry sand) and SF content (0.25–1 % by weight of dry soil). These blocks undergo comprehensive tests to determine their strength and durability. Wet and dry compression, flexural tests and indirect tensile tests were used to assess strength qualities, while wetting-drying cycles and acid exposure were used to determine durability. MSWIBA replaces 20 % sand in CSEB satisfying the strength. However, exceeding this amount increases void content and lowers strength, emphasizing the importance of balanced proportions for best performance. The 20 % MSWIBA and 0.75 % SF combination enhanced the compressive strength by 6.45 MPa, flexural strength by 0.92 MPa and water absorption by less than 18 %. The durability test displayed increases in compressive strength of 14.7 % and flexural strength of 93.48 % and optimized water absorption rate. Furthermore, microstructural analysis has been performed on CSEBs and the results highlight the importance of balanced cement and SF proportions for structural integrity. Life Cycle Analysis (LCA) investigation shows that construction costs using CSEB are 12.24 % higher than those with FCBs. Additionally, the study suggests that CSEB with MSWIBA and SF will be an environmentally sustainable construction material, considering factors such as energy usage, Global Warming Potential, and other environmental considerations

Green business process management in a Polish municipal waste treatment plant-regional case study

Despite COVID-19, the world economy still contributes to the growth of production and consumption worldwide. Waste disposal, recycling management and energy generation are challenges for many companies in developing economies, including Poland. This article aims to assess the operation of a municipal waste treatment plant (MWTP) from the perspective of green business process management (BMP) solutions. The processes implemented in the MWTP were discussed, with specific consideration of the mechanical waste processing (sorting) process, including the reuse and recycling of materials, composting, energy production (anaerobic process), landfill storage and efficiency parameters of the sorting line. A sustainable waste management system was identified; the cost as well as social and environmental perspectives were analyzed. Also, strategic goals and key performance indicators were considered. The performed analysis included costs, environmental criteria and key environmental indicators. This paper has shown the successful implementation of green BPM, with potential cost and material savings results. The findings of this case study are expected to inspire other waste management companies to adopt green BPM. The presented case study might help raise awareness and promote the implementation of green BPM in municipal plants in Eastern and Southern Europe.

Investigating the Role of Municipal Waste Treatment within the European Union through a Novel Created Common Sustainability Point System

Over the last several decades, the European Union (EU) has championed recycling and sustainable waste management through Directives 2008/98/EC and 2018/851, shaping practices across its member states. Currently, 30% of the EU’s municipal waste is recycled, 19% composted, 23% incinerated, and 23% landfilled. However, regional variations exist within the EU, with Greece and other Mediterranean/Balkan nations favoring landfilling, while Germany and other Western/Central EU nations prioritize recycling and composting, and Nordic countries lean toward incineration. To address these differences, a new sustainability point system was created in order to evaluate and compare all different municipal waste management strategies of EU members. Notably, countries like Germany, the Netherlands, and Sweden score the highest due to low municipal waste generation, high recycling rates (&gt;35%), minimal landfilling (&lt;1%), and significant incineration. In contrast, Cyprus, Malta, and Greece score lower due to landfill reliance and lower recycling rates. Therefore, this study introduces a novel sustainability point system to mitigate disparities, highlighting the need for targeted interventions and policy initiatives at the national and EU levels. By leveraging these insights, policymakers can allocate resources effectively, foster collaboration, and motivate citizens to achieve common environmental goals as well as the Sustainable Development Goals (SDGs).

Ignition and fire-related incidents caused by lithium-ion batteries in waste treatment facilities in Japan and countermeasures

Ignition and other fire-related incidents have been increasing at municipal waste treatment and small waste electrical and electronic equipment (WEEE) recycling facilities in Japan. To understand the current status of lithium-ion battery (LIB)-caused ignition and other incidents and to provide information necessary for countermeasures, we conducted interviews at municipal treatment facilities, did real-time monitoring at a treatment facility, and surveyed LIB mixed in non-combustible waste. Several treatment facilities had more than 0.1 ignition and other incidents per tonne of non-combustible and bulky waste collected in FY2020. These accidents were attributed to LIBs in 80–90 % of the cases, primarily because of physical impact on the LIBs during the crushing/shredding stage, even though LIB-containing small WEEE accounted for only about 0.3 % of the total weight of non-combustible waste. The best way to prevent the occurrence of such LIB-caused ignition and other incidents is to avoid crushing/shredding LIB-containing small WEEE.

Synergistic effects of economic benefits, resource conservation and carbon mitigation of kitchen waste recycling from the perspective of carbon neutrality

Kitchen waste, accounts for 40 %∼60 % of China's municipal solid waste, which recycles not only avoid waste of resources, but also reduces greenhouse gas emissions. Based on the survey data of Beijing municipal waste treatment plant, this study uses life cycle assessment to evaluate three kinds of kitchen waste treatment modes: aerobic composting, anaerobic digestion and anaerobic synergy. Then we analyze the technical feasibility, economic benefits and mitigation potential of three waste treatment modes. The anaerobic synergy has the highest technical feasibility and economic benefits. The total carbon emissions of different modes, through quantifying its emissions of collection, transportation, disposal and leakage, was aerobic composting > anaerobic digestion > anaerobic synergy. If all kitchen waste were treated with anaerobic synergy, cumulative carbon mitigation per person during 2025∼2060 was expected to 1019.2—1813.2 kg. Thus, recycling kitchen waste has a large mitigation potential to achieve China's carbon neutrality.

Impact of the New Electricity Remuneration Scheme on the Waste-to-Energy Recovery Activity in Portugal

The remuneration scheme for the electricity produced by Waste-to-Energy (WtE) recovery plants has changed recently in Portugal according to 2020 legislation. The new model, linking the electricity remuneration from WtE plants to the spot electricity prices, is expected to bring greater uncertainty in the waste activity, which is a novelty for the sector. In Portugal, Valorsul is the municipal waste treatment entity responsible for the recovery and treatment of municipal solid waste (MSW) produced in 19 municipalities in the Lisbon area. This paper highlights the impact of the new Portuguese electricity remuneration scheme for electricity from waste on Valorsul’s WtE plant. For this purpose, the new remuneration scheme is modeled and simulated based on electricity spot market price scenarios, which are compared with the base case scenario of the former remuneration scheme. Considering different electricity prices for the electricity produced by the WtE plant, the present study anticipates the consequences of the gate-fee of such regulatory changes. Results show that any price changes in the electricity remuneration scheme are offset by equivalent changes in the waste gate-fee. Consequently, the change in the remuneration of the electricity from the WtE plant is, in fact, neutral for the Valorsul accounts and lower revenues from the electricity generation activity of the WtE will negatively impact the gate-fee prices paid by the waste users.

Development of a plastic waste treatment process by combining deep eutectic solvent (DES) pretreatment and bioaugmentation with a plastic-degrading bacterial consortium

Polyethylene terephthalate (PET), a petroleum-based plastic, and polylactic acid (PLA), a biobased plastic, have a similar visual appearance thus they usually end up in municipal waste treatment facilities. The objective of this project was to develop an effective PET and PLA waste treatment process that involves pretreatment with deep eutectic solvent (DES) followed by biodegradation with a plastic-degrading bacterial consortium in a composting system. The DES used was a mixture of choline chloride and glycerol, while the bacterial strains (Chitinophaga jiangningensis EA02, Nocardioides zeae EA12, Stenotrophomonas pavanii EA33, Gordonia desulfuricans EA63, Achromobacter xylosoxidans A9 and Mycolicibacterium parafortuitum J101) used to prepare the bacterial consortium were selected based on their ability to biodegrade PET, PLA, and plasticizer. The plastic samples (a PET bottle, PLA cup, and PLA film) were pretreated with DES through a dip-coating method. The DES-coated plastic samples exhibited higher surface wettability and biofilm formation, indicating that DES increases the hydrophilicity of the plastic and facilitates bacterial attachment to the plastic surface. The combined action of DES pretreatment and bioaugmentation with a plastic-degrading bacterial consortium led to improved degradation of PET and PLA samples in various environments, including aqueous media at ambient temperature, lab-scale traditional composting, and pilot-scale composting.

Application of q-rung orthopair fuzzy based SWARA-COPRAS model for municipal waste treatment technology selection.

Despite several methods available for the treatment of solid wastes, the management of municipal solid waste is still a crucial and complex process. The available methods for waste treatment range from advanced to conventional techniques. The identification of a proper method for municipal solid waste management involves several techno-eco and environmental considerations. To solve the real-world problems of municipal waste management, the research proposed an integrated q-rung orthopair fuzzy number-based stepwise weight assessment ratio analysis-complex proportional assessment (SWARA-COPRAS) mathematical model to rank the waste treatment techniques. The research aimed to develop a systematic approach for a suitable selection of waste treatment methods. Ten (10) different alternatives for waste treatments were ranked against seven (07) different techno-eco and environmental criteria. The ambiguity in the decision was handled by the q-rung orthopair fuzzy numbers. The proposed integrated model has identified upcycling and recycling of waste having priority values of 100% and 99.9%, respectively, as the suitable practices for the successful management of generated solid wastes, whereas landfilling has obtained a minimum priority value of 66.782% and, therefore, is least preferable for waste management. The ranking of the alternatives followed the sequence as upcycling > recycling > pyrolysis > hydrolysis > biotechnological > core plasma pyrolysis > incineration > composting > gasification > landfilling. The comparison between the rankings of the proposed model with other techniques has revealed that the values of Spearman's rank correlation coefficient are in the range of 0.8545 to 0.9272; thereby, the robustness of the proposed model is verified. Sensitivity analysis for the criteria weight has showed that the ranking results are influenced significantly by the change in criteria weights and suggested that an accurate estimation of the criteria weight is decisive in determining the overall ranking of the alternative. The study has provided a framework for decision-making in the technology selection for solid waste management.

Circularity and Municipal Waste in Romania An Evaluation between 2011 and 2021

Abstract With the aim of moving to a circular economy, as specified in the European Union amending Directive 2018/851, by the year 2025, member states must reach a level of at least 65% by weight in the preparation for reuse and recycling of municipal waste, with the possibility of a 5-year postponement, under certain conditions. However, the generation of municipal waste has registered an increasing trend, due to the low recycling rates in many member states of the European Union, the low inefficiency of the collection systems and the poor implementation of the legislation in force. Through the research carried out, we want to highlight the trends regarding the generation, treatment, and recycling rates of municipal waste in Romania, in the period 2011-2021, but also the degree of fulfillment of the assumed targets regarding municipal waste. For this, we used the European databases available for the indicators selected in the research, as indicators of a circular economy. The analysis undertaken showed that in the last decade the amount of municipal waste per capita has increased, but it is far below the European Union average. Regarding the treatment of municipal waste, it is noted that the main operation is still landfill disposal and other similar operations, with an increasing trend compared to the base year of the analysis and contrary to the specifications of the European Union Framework Directive on waste, according to which waste disposal should be the last choice, when we consider the hierarchization of waste. The recycling rate of municipal waste was only 11.3% in 2021 and put Romania in last place in the ranking of the member states of the European Union. The bio-waste recycling rate did not have good values either; this was 14 kilograms per capita, decreasing in the analyzed period and well below the European Union average.

Impact of sandwich-type composite anodic membrane on membrane fouling and methane recovery from sewage sludge and food waste via electrochemical anaerobic membrane bioreactor

Membrane fouling presents a big challenge for the real-world implementation of anaerobic membrane bioreactors (AnMBRs) in digesting high-solid biowastes. In this study, an electrochemical anaerobic membrane bioreactor (EC-AnMBR) with a novel sandwich-type composite anodic membrane was designed and constructed for controlling membrane fouling whilst improving the energy recovery. The results showed that EC-AnMBR produced a higher methane yield of 358.5 ± 74.8 mL/d, rising by 12.8% compared to the AnMBR without applied voltage. Integration of composite anodic membrane induced a stable membrane flux and low transmembrane pressure through forming an anodic biofilm while total coliforms removal reached 97.9%. The microbial community analysis further provided compelling evidence that EC-AnMBR enriched the relative abundance of hydrolyzing (Chryseobacterium 2.6%) bacteria and methane-producing (Methanobacterium 32.8%) archaea. These findings offered new insights into anti-biofouling performance and provided significant implications for municipal organic waste treatment and energy recovery in the new EC-AnMBR.

Sequential Methodology for the Selection of Municipal Waste Treatment Alternatives Applied to a Case Study in Chile

Most municipalities in developing countries lack technical and economic resources to improve their municipal solid waste management (MSWM) system. Therefore, tools are needed that enable the most appropriate solutions to be identified to put waste to better use. This study presents an easy-to-apply sequential methodology for the analysis of MSWM alternatives. The method consists of two stages: (1) screening available technologies based on a small set of key variables; (2) ordering the selected alternatives by a combination of multicriteria methods that integrate local priorities. For this second stage, a basic series of technical, environmental, economic and social indicators is proposed. The methodology is applied to a case study where current management is limited to mixed municipal solid waste (MSW) disposal in a landfill without gas recovery. Seven options for implementing energy recovery in landfill, using mechanical plants to recover part of recyclable material, treating the organic fraction, and employing refuse-derived fuel and/or waste to energy incineration, were evaluated together with the current situation and considering four scenarios. The results identify various alternatives that allow the sustainability of MSWM in the case study to improve. Notwithstanding, today, it is necessary to introduce economic instruments that discourage final disposal to make municipal waste recovery viable.

The Use of Field Olfactometry in the Odor Assessment of a Selected Mechanical–Biological Municipal Waste Treatment Plant within the Boundaries of the Selected Facility—A Case Study

Odor management plans indicate the need to identify odor sources in waste management facilities. Finding the right tool for this type of task is a key element. This article covers a new approach for odor quantification and source identification at a selected waste management facility by coupling field olfactometry and the spatial interpolation method, such as inverse weighted distance. As the results show, this approach works only partially. Field olfactometry seems to be a suitable tool for odor identification that could be an instrument incorporated into odor management plans as it allowed for recognition of most odor-generating places at the selected facility, i.e., waste stabilization area, green waste storage area, and bioreactors. However, spatial distributions obtained by the selected interpolation method are characterized by high errors during cross-validation, and they tend to overestimate odor concentrations. The substantial weakness of the selected interpolation method is that it cannot handle points where the odor concentration is below the detection threshold. Therefore, the usefulness of such a method is questionable when it comes to odor management plans. Since field olfactometry is a reliable tool for odor measurements, further research into computational methods is needed, including advanced interpolation methods or dispersion modeling based on field olfactometry data.

Theoretical study on nitrogen migration mechanism during the pyrolysis of 2-pyrrolidone

Incineration is one of the mainstream techniques for the treatment of municipal waste. As the main component of municipal waste, kitchen waste incineration releases a large amount of NOx pollutants. Pyrolysis is the initial stage of incineration, during which nitrogen species in kitchen waste are converted into NOx precursors. In this study, nitrogen migration mechanism of NOx precursors (i.e., HNCO, HCN, and NH3) during the pyrolysis of 2-pyrrolidone, a typical lactam compound in kitchen waste, was investigated based on density functional theory calculations. Various formation pathways of HNCO, HCN and NH3 were discovered respectively. Meanwhile, the pathways of HNCO decomposition to HCN and NH3 at high temperature were illustrated. The formation and decomposition pathway of HCNO satisfactorily interpreted the experimental finding in which HNCO release curve decreased with the temperature rise. Furthermore, the reason for the high yield of HCN as the main product throughout the experimental temperature range and its insensitivity to temperature variation was also identified theoretically in this study.

Development of Solid Municipal Waste Treatment System within Circular Economy Framework

Development of Solid Municipal Waste Treatment System within Circular Economy Framework