Municipal Solid Waste Separation Research Articles

Electricity Generation Potential Forecast of Beijing Municipal Solid Waste Separation Rate Based on GRA-BiLSTM Model

Electricity Generation Potential Forecast of Beijing Municipal Solid Waste Separation Rate Based on GRA-BiLSTM Model

Reciclacentros: a sustainable municipal solid waste management initiative in a Mexican city

Due to the increase in the generation of municipal solid waste and its impact on the environment and health, governments have been overburdened by its impact. Therefore, they have developed initiatives for waste disposal options in which citizens are involved. For that reason, this article aims to identify the population sector that participates in the separation of municipal solid waste and goes to the collection centers, as well as to characterize waste in three points known as Reciclacentros in the city of Hermosillo, Sonora. For this purpose, surveys were applied, selecting the respondents in a non-probabilistic way. In the characterization, the amount of waste received at each point was weighed. The data obtained were analyzed through a non-parametric Kruskal - Wallis test with 95% confidence (p<0.05). It was found that the people going to the Reciclacentros have an average monthly income of more than 30 thousand Mexican pesos, mostly young adult women between 25 and 44 years old, with the highest participation. In addition, the collection center identified as R3 presented a significantly higher difference in waste received with respect to the other collection centers in the period evaluated (23 t). Cardboard and paper, plastic, and glass are the most recovered waste in the city.

Comprehensive environmental performance of bottle-to-bottle recycling of PET bottles based on deposit-refund system in China

Polyethylene terephthalate (PET) is a widely used packaging material and has high value in recycling. However, under China’s dominant informal recycling system, most PET bottles are downcycled into fibers. The deposit-refund system (DRS) is considered a feasible mechanism to facilitate the high-value recycling of PET bottles. To comparatively evaluate the environmental performance [reduction of greenhouse gas (GHG) and pollutant emissions] under different scenarios using life cycle assessments, including the current system based on informal recycling, an improved system with a larger contribution from the source separation of municipal solid waste, and evolving systems with DRS application, five scenarios were set up. The DRS can reduce GHG emissions and the comprehensive environmental impact by 0.538 kg CO2 /kg PET bottles and 1.73 × 10−3 PE/kg PET bottles, respectively, compared to informal recycling. It can be concluded that the DRS-based recycling approach and the bottle-to-bottle recycling provide the substantial emission reduction potential of GHGs and pollutants.

What establishes citizens' household intention and behavior regarding municipal solid waste separation? A case study in Jiangsu province

Management of municipal solid waste in China requires special attention because China has become the world's largest producer of municipal solid waste, and the overall volume of municipal solid waste produced is still increasing. Recently, local and central Chinese authorities have significantly enhanced municipal solid waste treatment. Therefore, this current study aims to extend the theory of interpersonal behavior with perceived benefits to assess citizens' household municipal solid waste separation intention and behavior in Jiangsu province. This study will help widen and improve the comprehension of the key factors affecting citizens' household municipal solid waste separation. Utilizing data from 615 sampled citizens in Jiangsu, analysis was conducted using partial least squares structural equation modeling. Empirical evidence revealed that affect, attitude, and social factors positively influence citizens' household municipal solid waste separation intentions. Perceived benefits also positively impact citizens' household municipal solid waste separation intentions via attitude. Facilitating conditions influence citizens' household municipal solid waste separation intentions and behaviors. The study also found that facilitating conditions negatively moderated the association between intention and behavior in Jiangsu Province. Habits significantly and positively influenced and moderated citizens' household municipal solid waste separation intentions and behaviors. These findings provide great insights and contributions to pro-environmental research and can be applied to various provinces that value household municipal solid waste separation in China.

ASSESSING RESIDENTS’ INTENTION TOWARDS MUNICIPAL SOLID WASTE SOURCE SEPARATION: A CASE STUDY OF MALAYSIA

This study investigates factors affecting Malaysian residents' municipal solid waste source separation behaviour. An extension of the theory of planned behaviour was applied by including the situational factor and perceived policy effectiveness in the model. A sample of 410 respondents was collected using convenient sampling methods. Data were analysed using the structural equation modelling-partial least-square (SEM-PLS) method on the hypotheses in the study. The findings revealed that attitude, subjective norms, perceived behavioural control, and perceived policy effectiveness significantly influenced residents’ municipal solid waste source separation intention. On the other hand, situational factors negatively impacted the municipal solid waste separation intention. Results further revealed that moral obligation and environmental knowledge positively influenced attitudes towards solid waste source separation. Thus, it is important for the government to increase Malaysian residents to perform solid waste source separation by providing adequate physical waste separation facilities with effective regulation enforcement.

The waste separation behaviour of primary and middle school students and its influencing factors: Evidence from Yingtan City, China

Waste separation at source has been proved to be an effective way to reduce the amount of municipal solid waste (MSW) which has become a major challenge to China’s ecological environment. However, waste source separation requires effort from each individual citizen. As the important drivers of change and potential influencers of the future world, younger Chinese’s waste separation behaviour is crucial to the long-term successful implementation of China’s MSW separation policy. To explore the waste separation behaviour of younger Chinese and identify the factors that may influence their behaviour so as to better encourage younger generation of Chinese to practice waste sorting in their daily lives, a questionnaire survey of 579 primary and middle school (PMS) students aged between 6 and18 years old (y/o) was carried out in Yingtan City, Jiangxi Province, China. Binary logistic regression was adopted to explore the factors that might influence the respondents’ waste separation behaviour. The results indicate that more than half PMS students in Yingtan have participated in waste separation, and junior year students perform better in waste separation practice than their seniors. Students are found to have basic knowledge of MSW classification, but they are more familiar with recyclable waste and hazardous waste than non-recyclable waste. The analysis also highlights positive relationships between PMS students’ attitude to waste separation, their willingness to do it, their environmental education and their waste separation behaviour. The level of convenience of waste sorting facilities and influences from friends and families are also positively related to the students’ waste separation practice, but families have the strongest influence. The perception of a mandatory waste separation policy would demotivate students in terms of waste separation practice, while giving rewards is considered to be the most effective approach to encouraging waste separation. Finally, management strategies for improving PMS students’ waste separation behaviour are discussed and several recommendations for improvement are made.

Assessment of the Applicability of Implementing Municipal Solid Waste Separation at Source in Jordan

Mismanagement of municipal solid waste results in risks to human health, threats to the environment, and other socioeconomic issues. Currently, most countries have realized that they are managing their waste in a traditional way, utilizing open dumping, and this way does not achieve sustainable development goals. Therefore, these countries, including Jordan, which is the case study for this paper, decided to manage their solid waste in a more integrated way. Waste separation at the source is an effective way to reduce the amount of waste produced and is essential for Jordan to achieve environmentally friendly and integrated municipal solid waste management. This paper aims to identify citizens' attitudes and readiness to be part of a proposed MSW source separation plan by dividing solid waste into two categories: wet waste in a green bag is disposed of daily for six days of the week, and dry waste in a blue bag is disposed of on the seventh day of the week. That was done through an online questionnaire with the participation of 150 respondents. The results showed that 68.7% shared their vision and strong readiness to start separation of household waste at source, and 28.7% agreed. The study further demonstrated that there is an urgent need to focus on solid waste separation at source and make efforts by local authorities to raise the citizens' commitment towards this methodology by introducing sound public awareness campaigns. Keywords : Solid waste management, Source Separation, Municipal Solid Waste, Jordan. DOI: 10.7176/CER/14-5-05 Publication date: September 30 th 2022

Ghanaian inclination towards household waste segregation for sustainable waste management

Global sustainable development goals call for universal access to safely manage sanitation by 2030. Municipal solid waste separation and management is critical in Ghana as in other developing nations, yet Ghana generates about 12,710 tonnes of municipal solid waste per day, and the byelaws regarding waste management are seldom enforced. This paper investigated the willingness of Ghanaians to separate household solid waste for proper sustainable waste management. Data was collected using a structured questionnaire through an online survey for 30 days in June 2021 and responses from 1406 participants were analysed using SPSS v.26. The study found 92.2% of respondents (irrespective of educational status and dwelling unit type) agreeing to the assertion that existing waste separation and management practices contribute to environmental pollution. It also found that effort by authorities to manage waste was unsatisfactory. Further, 61% and 18% of respondents use refuse bins and plastic/polythene bags to temporarily store waste respectively while the rest used inappropriate storage receptacles. Only 41.8% of generated waste are collected and managed by waste management companies or through paid laborers yet some 65.3% preferred a door-to-door collection system. About 90.5% of respondents agreed that recycling household waste will drastically reduce pollution, 67.4% were aware of waste segregation and 72.1% were in favour of segregation if it was a requirement. Interestingly, the study established that educational status does not influence one's awareness of waste segregation (p-value =0.759), yet the educated class know that household waste can be recycled into other uses to reduce pollution (p-values (0.03, 0.025); Pearson R=6.99, 7.415). The study recommends awareness creation through public education and the provision of multiple waste bins to aid in waste separation

Life Cycle Assessment of Existing and Alternative Options for Municipal Solid Waste Management in Saint Petersburg and the Leningrad Region, Russia

A waste reform was recently introduced in Russia to divert waste from landfills. To help advance the reform, this paper presents a life cycle assessment of the municipal solid waste management system in Russia’s second largest city—Saint Petersburg—and its neighboring Leningrad region. Five scenarios were evaluated: the current state of the system (S0), its expected post-reform state in 2024 (S1), and its state improved by increased landfill gas collection (S2), by increased waste incineration (S3), and by separate collection of waste (S4). The environmental impact was assessed in terms of climate change, acidification, eutrophication, and abiotic resource depletion (fossil fuels). The results showed an overall reduction in the environmental impact of the waste management system across all impact categories and all scenarios studied. The largest reduction in all impact categories (except abiotic resource depletion) was achieved through source separation of municipal solid waste. Particularly, global warming potential was reduced from 0.328 kg CO2-eq./kg waste generated in S0 to 0.010 kg CO2-eq./kg waste in S4. Regarding abiotic resource depletion potential (fossil fuels), the incineration scenario is the most beneficial, since it reduces the impact by 573%.

Assessment of Belief Constructs to Support an Intervention in Municipal Solid Waste Separation at the Source in Low–Middle-Income Countries: Observations from the Greater Accra Region of Ghana

This article uses a modified model of the theory of planned behaviour to assess salient beliefs of household heads towards the separation of municipal solid waste at its source in the Greater Accra Region of Ghana. Structural equation modelling was used to analyse the responses of 598 household heads to a questionnaire in a cross-sectional design. Whilst the default model produced an acceptable fit to the data and explained 37% of the variance in households’ intention to separate waste at its source, the modified model with moral norms as an additional construct fitted the data excellently, explaining 52% of the variance in intention. Moral norms and perceived behavioural control were the predominant latent constructs to influence intentions. Control beliefs related to the availability of waste receptacles, provision of regular waste collection services, and access to knowledge of the separation process had the greatest tendency to facilitate households’ intentions. Pro-environmental interventions designed in a participatory manner to promote moral correctness, responsibility, respect for the environment, and positive affect may empower households to separate waste at its source. This research contributes to the development of a municipal solid waste strategy in the region, and may further support research in waste diversion and the circular economy in other jurisdictions.

Evaluating the capability of municipal solid waste separation in China based on AHP-EWM and BP neural network

With the increase in municipal solid waste (MSW), most cities face solid waste management issues. In this study, the analytic hierarchy process (AHP) and artificial neural network (ANN) models were improved to assess the MSW separation capability based on 18 selected indicators of solid waste separation in 15 cities in China. The entropy weight method (EWM) was used in AHP to optimize and determine the indicators and then evaluate their weights, which showed that the general public budget expenditure had the highest weight (0.5239). This implied that the MSW separation capability could be mainly influenced by government financial support. ANN based on scan optimization and machine learning methods were established (R2 = 0.9992) to predict the missing indicators. The mapping relationship between MSW separation indicators and capabilities was also significantly improved from R2 = 0.5317 to R2 = 0.9993, thereby increasing the prediction accuracy of MSW separation capabilities to 95.15%. Thus, this research provides a new avenue for MSW separation and establishes a combined model to predict the separation capability in practical applications.

Low carbon potential of urban symbiosis under different municipal solid waste sorting modes based on a system dynamic method

Urban symbiosis (UrS) is an innovative application of circular economy focusing on municipal solid waste (MSW). However, few studies have been conducted to forecast the impact of UrS on climate change under different MSW sorting policies such as four-category/two-category MSW separation standards and high/low sorting rates from a long-term and dynamic perspective. This study develops a system dynamics model to simulate the greenhouse gas (GHG) emission reduction potential and the energy saving potential of UrS under different MSW sorting modes in Shanghai for the period of 2020–2050. The results show that UrS with four-category MSW separation and a high sorting rate (scenario S1) has the highest energy saving and GHG reduction potential at both annual level and accumulative level, approximately 10.75 times the energy saving and 146.30% of the GHG emission reduction compared with the Business-As-Usual (BAU) scenario in 2050. Meanwhile, the scenario of two-category MSW sorting and a high sorting rate (S3) can further help reduce 12.84% GHG emissions than the scenario of four-category MSW sorting and low sorting rates (S2) in 2050. Among all the UrS measures, waste plastic recovery can contribute the most GHG emission and energy consumption reductions, with figures of approximately 2.15 Mt and 17.28 Mtce, respectively. Finally, policy recommendations on strengthening implementation of four-category MSW separation, making efficient two-category MSW separation as a backup plan, and promoting reutilization of waste plastic and Refuse Plastic & Paper Fuel technology are proposed.

Analysis of influencing mechanism on waste separation behavior in Shanghai

Residents are responsible for community waste separation, and their waste separation behavior plays a significant role in determining the success or failure rate of waste management. In industrializing countries, countries such as China, waste separation at the origin is a critical factor in the success of the entire strategy implementation. Establishing trash source-separated gathering relies primarily on resident engagement, which necessitates a full knowledge of how sentiments, behavioral intention, perceived behavioral control, and contextual circumstances influenced their overall behavior. This learning customs the theory of planned behavior to analyze waste separation practices in Shanghai, that will contribute to enhance the domestic household waste separation behavior measuring scale, as well as differentiate and improve residents' waste separation commencement, execution objectives and construct a theoretical model that identifies the factors that influence waste separation behaviors. This study uses random stratified data on the waste separation behaviors of Shanghai residents across 16 districts and counties in 2019. A sample of 2555 questionnaire responses was analyzed, and a structural equation model was used to identify the mechanisms that influence residents’ environmental attitudes, subjective norms, and perceived behavior control concerning waste separation behavior in the context of government regulations. The study found that environmental attitudes, subjective norms, and perceived behavior control significantly and positively affect the initiation and execution intentions of residential waste separation, which in turn positively affects waste separation. Environmental attitudes, directly and indirectly, affect waste separation behaviors through initiation and execution intentions. Indirectly, subjective norms and perceived behavioral control have little effect on waste separation. The operational influence of initiation intention on trash separation is moderated by perceived policy effectiveness. Only environmental views, on the other hand, influence inhabitants' trash separation habits. Perceived policy effectiveness promotes the transformation of initiation intention into waste separation behaviors. The findings expanded the application of the planned behavior theory of waste separation, contributed to a better understanding of the behaviors of municipal solid waste separation in Shanghai and other Chinese cities, and provided decision makers with policy suggestions for the governance of waste separation.

Environmental Assessment of the Recycled Paper Production: The Effects of Energy Supply Source

The main aim of the study was to assess the environmental performance, through the application of the life cycle assessment, of a recycled paper production process focusing on the energy aspect. The production process occurred in a paper mill that produces packaging paper using paper and cardboard from source separation of municipal solid waste as raw materials. Two scenarios (S1 and S2) were defined by their energy supply sources. A cogeneration (CHP) system using natural gas for the combined production of thermal and electric energy was the source in S1. The Italian electricity grid (using the Italian country mix) and a natural gas boiler were the separate sources for electric and thermal energy, respectively, in S2. Finally, in order to evaluate the environmental effects on the results of the study about the variation in the natural gas supply source, four alternative Italian import mixes (M1, M2, M3, and M4) were defined by varying the contribution of the supplier countries. The environmental impacts were evaluated with ReCiPe 2016 (H) using both midpoint and endpoint approaches. The results showed that for both the scenarios, the energy consumption was the main cause of impacts mainly because of the natural gas contribution. The presence of the cogeneration (CHP) system generated significant environmental benefits compared with the use of energy provided by more conventional sources. The production and use of chemicals as well as the disposal of waste produced during the paper production were other environmental hotspots. The variation in the composition of the Italian import mix of natural gas, in terms of the supplier country’s contribution, had a significant influence on the results. The import of natural gas from Russia was the most impactful option. Since Russia is the country that contributes to the Italian import mix the most, in the next years, the use of natural gas in Italy could become increasingly impactful. Therefore, the replacement of natural gas with renewable sources is an urgent priority.

Environmental damage cost assessment from municipal solid waste treatment based on LIME3 model

Environmental damage cost can measure the impact of pollution caused by human activity on final safeguard subjects from endpoint perspective. Application of environmental damage cost to municipal solid waste (MSW) management is still rare. To fill such a research gap, this study established a MSW environmental damage cost assessment method using Life Cycle Impact Assessment Method based on Endpoint (LIME) model. Four types of environmental damage cost, namely, primary productivity, social assets, biodiversity and human health for waste treatment were investigated in the city of Shanghai. Results show that the environmental damage cost was 113.7, 116.9, 140.0, 144.0 and 170.8 million dollars in Shanghai from 2014 to 2018, respectively. Damage cost of social assets was the dominant component, accounting for about 55%. Landfill mainly caused social assets damage cost, while incineration mainly caused human health damage cost. Scenarios analysis further revealed that after implementing MSW separation, the total environmental damage cost could be reduced by about 1/3. The best MSW treatment method is fermentation, followed by compost, incineration and landfill, with unit environmental damage cost being 0.22, 4.51, 16.04 and 23.47 USD/ton, respectively.

A Comprehensive Review of Biomethanation of Urban Food Waste in Nairobi City County, Kenya

Organic waste in Nairobi City County accounts for 58-63% of the municipal solid waste generated. Food waste is at the center of urban waste management in the city as it accounts for 64% of the recoverable material. The city is estimated to have a food waste generation per capita of 6.1 kilogram per year, which accumulates to 29.4 thousand tons yearly. It transpires that upstream activities of the food supply chain, mainly production, postharvest loss, processing and distribution are the major food waste hotspots, accounting for 95% of the food waste in developing countries. Additionally, downstream activities of the food supply chain show that hotels, restaurants and super markets are the most important food waste hotspots. Such food waste hotspots should become the primary targets for resource recovery in a circular economy. Currently, the exploitation of food waste for animal feed and composting is growing in Nairobi City County, which signifies that food waste is becoming a valuable urban resource that can be traded, thus creating employment. However, the application of food waste for energy recovery through anaerobic digestion is limited in the city due to lack of source separation of municipal solid waste. On average, food waste has a biomethane potential of 508.45 ml CH₄ /g VS. This implies that 29.4 thousand tons of food waste generated in Nairobi City County has the potential to yield 10.5 million m³ of methane, and will demand a digestion volume of 4,299 m³. Using global case studies of electricity generation from biogas, it is estimated that food waste in the city potentially yields 1.38 MW of electricity. In addition, about 26.1 thousand tons of bioslurry can be recovered from the digestion of food waste, which can be used for urban agriculture. Regardless of the liquefied petroleum gas enjoying a tax exemption, biogas at 32.78 USD per gigajoule of delivered energy demonstrates to be more economical, and this can be enhanced by upgrading it. The removal of liquefied petroleum gas from tax-exempt goods through the Finance Act 2020, and an addition of 16% value added tax on the fuel by Kenya Revenue Authority that became effective on 1^st July, 2021 favors biofuels such as methane. However, long term realization of methane generation potential in NCC demands the adoption and implementation of more friendly biofuels policies and regulatory frameworks in the country.

Greenhouse gas emission mitigation potential from municipal solid waste treatment: A combined SD-LMDI model

Fast urbanization and economic prosperity generate huge amount of municipal solid waste (MSW). It is therefore critical to identify the determinants of greenhouse gas (GHG) emissions from MSW treatment and prepare potential GHG mitigation measures. A combined System Dynamics - Logarithmic Mean Divisia Index model is developed to identify the driving forces of GHG emission generated from MSW treatment and explore the mitigation potentials. Shanghai, a typical megacity in China is selected as a case study. Results showed that economic development, population scale and emission intensity were driving forces to induce GHG emissions from MSW treatment, while generation intensity and treatment structure were the factors to mitigate GHG emissions from MSW during 2000–2017. Scenario analysis further revealed that landfill gas utilization and MSW separation improvement were the most effective measures in reducing GHG emissions from MSW treatment, leading to about 88.07% and 85.48% of reduction compared with the business-as-usual scenario in 2050. Scenarios of improving incineration rate, reducing per capita MSW generation and restricting population growth will reduce GHG emissions by 72.29%, 30.06% and 0.30%, respectively. Utilizing landfill gas, improving MSW separation and promoting green behaviors are suggested to mitigate GHG emissions from MSW treatment.

Separation of biodegradable material from the low calorific fraction of municipal solid waste

The increasing concerns regarding climate change and depletion of raw materials motivate governments to intensify their actions towards a cleaner energy matrix, independent of fossil fuels, and a more sustainable material supply chain. In this context, municipal solid waste (MSW) is of major interest, considering it contains a variety of potentially valuable materials, such as biomass (e.g. food and green waste) and recyclables (e.g. plastics, glass, mineral fractions, etc.). However, when suitable local infrastructure for the separation of these materials does not exist, MSW is usually discarded in landfills or thermally treated. Often, the thermal treatment involves transportation over long distances. The objective of this work was to develop a pilot mechanical pretreatment system for the separation of MSW (fraction <12 mm) into a substrate rich in biodegradable material for local valorization. The developed pretreatment consists of a sieving step followed by a mixing unit, which produces a suspension to be fed into a hydrocyclone. The impurity separation efficiency of the hydrocyclone was evaluated for different total solids (TS) of the suspension and for different volume flows (VF). For practical applications, the TS of 9% and VF of 10 m³/h presented the optimal arrangement for impurity removal. In addition, after passing the MSW-derived suspension through the hydrocyclone three times, it was possible to increase the concentration of biodegradable material from 40% TS to 65% TS. The removed impurities consisted of 90% minerals, glass and metals, presenting potential of further processing for the extraction of secondary raw materials prior to landfilling. The specific electricity demand of the proposed wet pretreatment was estimated at 3.2 kWh/t of MSW <12 mm processed.

Why does waste separation policy vary across different Chinese cities? A configurational analysis of the pilot scheme

This study aims to explain why different policy instruments are selected and how different configurations of factors influence the policy selection in waste management in China. Firstly, we perform content analysis with Nvivo 11 to illustrate the regional variance in policy instrument choice among the 46 cities selected as pilots to enforce the separation of municipal solid waste (MSW). While some local governments mainly resort to regulatory instruments, some others show inclination toward incentive instruments. The authors then explore the mechanisms shaping local government’s policy instrument choice with the configurational approach of fussy-set Qualitative Comparative Analysis (fsQCA), which has been seldom conducted empirically. The analysis generates several significant implications for policy instrument choice in waste management in China. It reveals how combinations of factors influence the instrument choice, which is difficult for regression analysis to capture. Second, it identifies equifinal causal paths to both incentive and regulatory instruments. Third, the fsQCA analysis also demonstrates the asymmetry of causality.

An overview of the municipal solid waste management modes and innovations in Shanghai, China.

Municipal solid waste (MSW) management and recycling has become an emerging issue in developing countries. Shanghai, the largest megacity in China, is well-known nationwide due to leading China's MSW separation and recycling. Therefore, this paper introduces the Shanghai mode for MSW management and its current situation to enrich existing MSW management studies. Results show that the total generation volume of MSW and amount of MSW generation per capita were 9.00 million tons and 372.16 kg in 2017, increased approximately eight-fold and four-fold compared with the data in 1978, respectively. The MSW treatment rate reached 100% since 2014, with incineration rate increased to 48.56% in 2017. The cost of MSW management after implementing MSW sorting regulation is increased to 985 CNY/ton, including 390 CNY/ton of MSW sorting cost. Then three key features and innovative MSW management modes, namely, mandatory MSW sorting legislation, Green Account program, and the Combined Network program are introduced. Meanwhile, two main challenges are urgent to be responded, including inadequate collecting vehicles and limited wet waste treatment capacity. Finally, policy recommendations on strengthening MSW recycling process, constructing complete terminal treatment industry, and making systematic policies were provided to respond existing challenges.