Solid Waste Management Solutions for a Rapidly Urbanizing Area in Thailand: Recommendations Based on Stakeholder Input

Insights into plastic food packaging waste sorting behaviour: A focus group study among consumers in Germany

Despite international efforts to foster the circular economy, plastic waste remains a major environmental problem. In the circular economy, the success of a waste management system depends, inter alia, on consumers properly sorting their plastic waste. Yet mis-sorting of plastic food packaging waste happens routinely. We sought to find out why and to outline the ways consumers prefer to receive information about waste sorting procedures. Tailoring information to consumer preferences can improve the effectiveness of waste management policy. Using the Motivation Opportunity Ability (MOA) framework to explain consumer behaviour, we conducted focus group discussions in two German cities. Our findings suggest that more accurate information and financial incentives best motivate consumers to sort waste correctly. Uncertainty and confusion over the packaging material are the most severe hindrances to correct sorting behaviour. The Internet and social media are preferred most for acquiring information on how to sort plastic food packaging correctly. Policymakers can use our results to adjust packaging and waste management regulations to help eliminate confusion among consumers and to facilitate their recycling intentions. Food industry practitioners and company decision makers can use our results to adjust their plastic packaging features to better match consumer preferences for easily recyclable waste.

Environmental pitfalls and associated human health risks and ecological impacts from landfill leachate contaminants: Current evidence, recommended interventions and future directions

The improper management of solid waste, particularly the dumping of untreated municipal solid waste, poses a growing global challenge in both developed and developing nations. The generation of leachate is one of the significant issues that arise from this practice, and it can have harmful impacts on both the environment and public health. This paper presents an overview of the primary waste types that generate landfill leachate and their characteristics. This includes examining the distribution of waste types in landfills globally and how they have changed over time, which can provide valuable insights into potential pollutants in a given area and their trends. With a lack of specific regulations and growing concerns regarding environmental and health impacts, the paper also focuses on emerging contaminants. Furthermore, the environmental and ecological impacts of leachate, along with associated health risks, are analyzed. The potential applications of landfill leachate, suggested interventions and future directions are also discussed in the manuscript. Finally, this work addresses future research directions in landfill leachate studies, with attention, for the first time to the potentialities that artificial intelligence can offer for landfill leachate management, studies, and applications.

Solid waste management in the context of the waste hierarchy and circular economy frameworks: An international critical review

Growing populations and consumption drive the challenges of solid waste management (SWM); globalization of transport, food production, and trade, including waste trading, distributes risks worldwide. Using waste hierarchy (WH; reduce, reuse, and recycle) and circular economy (CE) concepts, we updated a conceptual waste framework used by international organizations to evaluate SWM practices. We identified the key steps and the important factors, as well as stakeholders, which are essential features for effective SWM. Within this updated conceptual framework, we qualitatively evaluated global SWM strategies and practices, identifying opportunities, barriers, and best practices. We find that, although a few exceptional countries exhibit zero-waste compliance, most fare poorly, as exhibited by the high waste generation, incineration, and disposal (open dumping, landfilling) volumes. In the Global North, SWM strategies and practices rely heavily on technologies, economic tools, regulatory frameworks, education, and social engagement to raise stakeholder awareness and enhance inclusion and participation; in the Global South, however, many governments take sole legal responsibility for SWM, seeking to eliminate waste as a public "nuisance." Separation and recycling in the Global South are implemented mainly by "informal" economies in which subsistence needs drive recyclable material retrieval. Imported, regionally inappropriate tools, economic constraints, weak policies and governance, waste trading, noninclusive stakeholder participation, data limitations, and limited public awareness continue to pose major waste and environmental management challenges across nations. In the context of the framework, we conclude that best practices from around the world can be used to guide decision-making, globally. Despite variations in drivers and needs across regions, nations in both the Global North and South need to improve WH and CE compliance, and enhance stakeholder partnership, awareness, and participation throughout the SWM process. Partnerships between the Global North and South could better manage traded wastes, reduce adverse impacts, and enhance global environmental sustainability and equity, supporting UN Sustainable Development Goals. Integr Environ Assess Manag 2024;20:9-35. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

The combined effects of binder addition and different sintering methods on the mechanical properties of bovine hydroxyapatite

Hydroxyapatite (HA) from bovine bones has been used as a biomaterial in dentistry due to its biocompatibility and bioactivity. However, dense HA bioceramics still present inadequate properties for applications that require high mechanical performance, such as infrastructure. Microstructural reinforcements and control of ceramic processing steps are methods to improve these shortcomings. The present study assessed the effects of polyvinyl butyral (PVB) addition in combination with two sintering methodologies (2-step and conventional), on the mechanical properties of polycrystalline bovine HA bioceramics. The samples were divided into four groups (with 15 samples per group): conventional sintering with binder (HBC) and without binder (HWC) and 2-step sintering with (HB2) and without binder (HW2). HA was extracted from bovine bones, turned into nanoparticles in a ball mill, and subjected to uniaxial and isostatic pressing into discs, according to ISO 6872 standards. All groups were characterized by x-ray diffractometry (XRD), differential thermal analysis (DTA) and Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and relative density. Besides, mechanical analyses (biaxial flexural strength (BFS) and modulus of elasticity) were also performed. The characterization results demonstrated that adding agglutinants or the sintering method did not affect HA's chemical and structural characteristics. Even so, the HWC group showed the highest mechanical values for BFS and modulus of elasticity being 109.0 (98.0; 117.0) MPa and 105.17 ± 14.65 GPa, respectively. The HA ceramics submitted to conventional sintering and without the addition of binders achieved better mechanical properties than the other groups. The impacts of each variable were discussed and correlated to the final microstructures and mechanical properties.

Integration of LCSA and GIS-based MCDM for sustainable landfill site selection: a case study

The paper aims at developing a framework for decision-support to select a sustainable landfill site in Bardaskan City (Iran) by combining life cycle sustainability assessment (LCSA) concepts and geographic information system (GIS)-based multi-criteria decision-making (MCDM). Overall, 13 criteria were chosen (three constraints and 10 factors) and classified into three main aspects of sustainability (i.e., environmental, social, and economic) to achieve the research goals. Boolean and fuzzy logic were employed to standardize the classified constraints and factors, respectively. Analytic hierarchy process (AHP) was used to calculate the factors' weights and then suitability maps were produced using the GIS analysis. The layers were combined using simple additive weighting (SAW). Next, the most sustainable sites were obtained. The results indicated that distance from city backline, groundwater depth, and distance from rural areas were the most significant factors with the weight of 0.338, 0.141, and 0.129, respectively. The final map of suitable sites was created by classifying the SAW layer according to 75, 80, and 85% of suitability to show the high, medium, and low priority areas for landfill site selection, respectively. Therefore, integration of LCSA and GIS-based MCDM to select the sustainable landfill site for municipal solid waste (MSW) is highly important, which can be effectively employed in regional and urban planning to select the location of appropriate and sustainable landfills.

Testing the stakeholders' partnership in a tourism waste management network: an ERGM approach

The exponential random graph model (ERGM) is an effective approach for testing the dynamic and local processes of a network. This paper explores the structure of stakeholders' partnerships in a tourism waste management network using high-order dependency ERGMs based on relational data obtained from a field survey in Motuo County, China. The results reveal that (1) the network has many edges, indicating a tight network; (2) the geometrically weighted edge distribution shows a high transitive effect of the network; (3) the structural effect is more significant than the attribute effect; (4) there is a good agreement between the simulation results and observations, suggesting a tourism waste network with close connections and collaborative division of labor. These findings indicate that different groups of stakeholders have been extensively involved in tourism waste management in Motuo County. The edgewise shared partners formed by stakeholders of different groups increase the information transmission efficiency of the network. The results have implications for tourism waste management, specifically for promoting sustainability transitions via network governance.

A survey of Knowledge, attitudes, and practices of Tehran residents regarding solid waste management in the COVID-19 era

This study aimed to investigate the knowledge, attitude, and practice (KAP) of residents in Tehran City towards municipal solid waste management (MSWM) after the Corona Virus Disease 2019 caused by SARS-CoV-2 (COVID-19) epidemic, which has been tended for the first time in this research. The study was conducted in Tehran, Iran from August 2021 to March 2022. The study population consisted of 385 participants drawn from 22 urban areas in Tehran. In order to collect the data, self-administered questionnaires containing 20 questions in 3 subject areas were used. Testing for associations between variables was conducted using Chi-square (χ2) and Pearson correlation analyses. Despite the fact that 64.9% and 56.6% of residents had adequate knowledge and attitude regarding MSW management during the COVID-19 pandemic, only 33.1% performed moderate practice. Obtained results highlighted the correlation between education, employment, gender, and age of respondents with KAP levels on (MSWM) (P<0.05). The training was found to be an important tool to enhance residents' awareness and attitude, but strict MSW legislation must also be implemented to restart appropriate separation, recycling, and composting programs during the pandemic. The findings of this study in turn can serve as a basis for experts and decision-makers to develop pragmatic waste management strategies during the COVID-19 pandemic, which rely on the participation of the general public.

Stakeholder Assessment on Closing Nutrient Cycles through Co-Recycling of Biodegradable Household Kitchen Waste and Black Water between Rural and Urban Areas in South India

Agricultural land degradation, urban migration, increasing food demand and waste, and inadequate sanitation systems all affect farmers, local society, and the environment in South India. Joint recycling of biodegradable secondary household resources to close nutrient cycles between urban and rural regions can address all these challenges and thus several SDGs at the same time. Efforts are being made to this end, but many attempts fail. The central research question is, therefore: how can co-recycling concepts be evaluated in this context? For this purpose, composting plants, biogas fermenters, and a high-tech concept to produce plant charcoal, design fertilizer, and biopolymers are considered. The aim of this study is to evaluate the recycling concepts from the stakeholders’ perspective to avoid gaps between theory and practice. Six expert and one focus group interviews on two successful on-site case studies and 15 online expert interviews with thematic actors were qualitatively evaluated and presented in a social network analysis to identify preferences and indicators for the further evaluation of co-recycling concepts. The results show that the focus is on mature technologies such as compost and biogas. High-tech solutions are currently still in rudimentary demand but will play a more important role in the future. To evaluate such concepts, seven key indicators and their measured values were identified and clustered into the categories ecological, social, technical, economic, and connective. The results show that this methodology of close interaction with stakeholders and the evaluation of successful regional case studies minimize the gap between practice and theory, contribute to several goals of the SDGs, and thus enable such concepts to be implemented sustainably.

Technologies for municipal solid waste management: Current status, challenges, and future perspectives

Municipal solid waste (MSW) is a reflection of the culture that generates it and has a negative impact on the health of the humans and the environment. In the global context, people are abandoning increasing volumes of garbage, and the content of that waste is becoming more complicated than it has ever been, as plastic and electronic consumer goods spread. At the same time, the world is rapidly urbanizing. These changes place a burden on cities to manage garbage appropriately on both a social and environmental level. Globally, extensive research has been conducted to develop a comprehensive MSW management system that includes treatment. The primary objective of this article is to examine municipal solid waste in eight of China's eastern coastal regions. With the use of this review, we found that MSW generation is increasing in Shandong, Guangdong, Zhejiang, and Fujian provinces, but declining in other eastern coastal cities, provinces, and special zones. Furthermore, municipal solid waste in China is treated utilizing 52 percent landfill, 45 percent incineration, and 3 percent composting techniques, resulting in significantly lower usage efficiency than in developed countries. The effectiveness of China's municipal waste management system must be improved. In addition, this review examines MSW management issues and prospects in China, as well as recommendations for strengthening the MSW management system.

Processes and prospects on valorizing solid waste for the production of valuable products employing bio-routes: A systematic review

Humanity is struggling against a major problem for a proper management of generated municipal solid waste. The collected waste causes natural issues like uncontrollable emission of greenhouse gases and others. Even though, escalation of waste results in minimizing the areas accessible for disposing the waste. Creating awareness in the society to use organic products like biofuels, biofertilizers and biogas is a need of an hour. Biochemical processes such as composting, vermicomposting, anaerobic digestion, and landfilling play important role in valorizing biomass and solid waste for production of biofuels, biosurfactants and biopolymer. This paper covers the details of biomass and solid waste characteristics and its composition. It is also focused to provide updated information about reutilization of biomass for value creation. Technologies and products obtained through bio-routes are discussed in current review paper together with the integrated system of solid waste management. It also covers challenges, innovations and perspectives in this field.

Eliciting local knowledge of ecosystem services using participatory mapping and Photovoice: A case study of Tun Mustapha Park, Malaysia

Protected areas in Malaysia have always been managed using top-down approach that often exclude the local communities, who are the main users of ecosystem services, from the planning and management. However, a newly established multiple-use marine park in Malaysia, Tun Mustapha Park (TMP), aims for inclusivity in managing the park. This research explores different participatory approaches (i.e. participatory mapping and Photovoice) to understand the ecosystem services and the dynamics surrounding the services in TMP. Community-based organisations and a mariculture farm in TMP were invited to participate in this work. The participants mapped the ecosystem services and provided in-depth qualitative data that supported the maps, besides highlighting ecological, sociocultural and economic issues surrounding the ecosystem services. Furthermore, the participants provided suggestions and recommendations that carry political effects. Therefore, the participatory approaches employed here had provided rich visual and spatial data to enhance the ecosystem-based management of TMP besides empowering the participants to voice out for their communities. The results generated from this work were also further utilised to fill in the gaps of knowledge in a separate ecosystem service assessment matrix. However, the output from participatory approaches should not be considered as the ultimate outcome but rather as supplement to the planning and management of TMP due to potential human errors and biases. Although the participatory approaches came with limitations and challenges that may have affected the findings here, these nonetheless had provided support to the capability of local communities to provide information crucial for management of protected areas as well as room for improvement for further work.

Testing the Role of Waste Management and Environmental Quality on Health Indicators Using Structural Equation Modeling in Pakistan

Improper management of municipal waste has become a growing concern globally due to its impact on the environment, health, and overall living conditions of households in cities. Waste production has increased because households do not adopt waste management practices that ensure sustainability. Previous studies on household waste management often considered socio-economic aspects and overlooked the environmental and behavioral factors influencing the disposal practices and health status. This study adopted four constructs, defensive attitude, environmental knowledge, environmental quality, and waste disposal, by employing a structural equation modeling approach to explore research objectives. Data from 849 households of the Islamabad-Rawalpindi metropolitan was collected by using a multi-stage sampling technique. The structural model results showed that the two constructs, environmental knowledge and defensive behavior, positively affect household health status. The most significant health-related considerations are waste disposal and environmental quality, both of which negatively impact health status and do not support our hypothesis. The results provide valuable perspectives to enable households to engage actively in waste management activities. The findings indicate that understanding the intentions of household health status drivers can assist policymakers and agencies in promoting an efficient and successful community programmes related to sustainable solid waste management by allowing them to foster how the desired behavior can be achieved.

Effects of improved information and volunteer support on segregation of solid waste at the household level in urban settings in Madhya Pradesh, India (I-MISS): protocol of a cluster randomized controlled trial

BACKGROUND

Segregation of household waste at the source is an effective and sustainable strategy for management of municipal waste. However, household segregation levels remain insufficient as waste management approaches are mostly top down and lack local support. The realisation and recognition of effective, improved and adequate waste management may be one of the vital drivers for attaining environmental protection and improved health and well-being. The presence of a local level motivator may promote household waste segregation and ultimately pro-environmental behaviour. The present cluster randomized control trial aims to understand if volunteer based information on waste segregation (I-MISS) can effectively promote increased waste segregation practices at the household level when compared with existing routine waste segregation information in an urban Indian setting.

METHODS

This paper describes the protocol of an 18 month two-group parallel,cluster randomised controlled trialin the urban setting of Ujjain, Madhya Pradesh, India. Randomization will be conducted at ward level, which is the last administrative unit of the municipality. The study will recruit 425 households in intervention and control groups. Assessments will be performed at baseline (0 months), midline (6 months), end line (12 months) and post intervention (18 months). The primary outcome will be the comparison of change in proportion of households practicing waste segregation and change in proportion of mis-sorted waste across the study period between the intervention and control groups as assessed by pick analysis. Intention to treat analysis will be conducted. Written informed consent will be obtained from all participants.

DISCUSSION

The present study is designed to study whether an external motivator, a volunteer selected from the participating community and empowered with adequate training, could disseminate waste segregation information to their community, thus promoting household waste segregation and ultimately pro-environmental behaviour. The study envisages that the volunteers could link waste management service providers and the community, give a local perspective to waste management, and help to change community habits through information, constant communication and feedback.

TRIAL REGISTRATION

The study is registered prospectively with Indian Council of Medical Research- Clinical Trial Registry of India ( CTRI/2020/03/024278 ).

Bioconversion of municipal solid waste into bio-based products: A review on valorisation and sustainable approach for circular bioeconomy

Municipal solid waste management is one of the major issues throughout the world. Inappropriate management of municipal solid waste (MSW) can pose a major hazard. Anaerobic processing of MSW followed by methane and biogas generation is one of the numerous sustainable energy source options. Compared with other technologies applicable for the treatment of MSW, factors like economic aspects, energy savings, and ecological advantages make anaerobic processing an attractive choice. This review discusses the framework for evaluating conversion of municipal solid waste to energy and waste derived bioeconomy in order to address the sustainable development goals. Further, this review will provide an innovative work foundation to improve the accuracy of structuring, quality control, and pre-treatment for the ideal treatment of different segments of MSW to achieve a sustainable circular bioeconomy. The increasing advancements in three essential conversion pathways, in particular the thermochemical, biochemical, and physiochemical conversion methods, are assessed. Generation of wastes should be limited and resource utilization must be minimised to make total progress in a circular bioeconomy.

Analyzing Waste Management System Alternatives for Kabul City, Afghanistan: Considering Social, Environmental, and Economic Aspects

Our earlier work identified social issues of stakeholders who are highly exposed to poor social performance in the current waste management system (WMS) of Kabul city, Afghanistan. The present work builds on earlier findings to elaborate four alternative scenarios with better social outcomes. For each scenario of the current system, greenhouse gas (GHG) and economic assessments were conducted. Results show that Scenario 2, considering increase waste collection coverage, recycling, unsanitary landfilling, and integration of informal workers, was found as the best alternative. Scenario 3, which added a source-separated system to Scenario 2, was the second-best alternative. These two scenarios address social issues and can reduce GHG emissions, save costs, and provide more jobs than the current system. In contrast, the absence of recycling in Scenario 1, and the conversion of unsanitary landfill into sanitary landfill in scenario 4 result in higher costs and GHG emissions, even though they deal with social issues and generate higher jobs to the existing waste management practice.

Why is there plastic packaging in the natural environment? Understanding the roots of our individual plastic waste management behaviours

Plastic waste is now a classic contaminant of the natural environment and the origins of the contamination need to be well understood. The transition from a useful object to a waste product is a fundamental moment that, from the point of view of the scientific literature, remains poorly understood. This review therefore aims to highlight some factors controlling this intentionality, but also those that influence individual waste management behaviours. For this purpose, an original approach involving the study of the amount of knowledge within different disciplinary fields of research has been employed. The results underline that the low direct impact of the consequences on their users of the discarding of plastic packaging seems to be an important reason for individual mismanagement. Furthermore, the modern individual behaviours of the discarding of plastics are often deeply rooted in the past of the populations. Policies to reduce waste disposal come up against strong individual behavioural constraints that limit the proper management of plastic waste. Thus, incivilities, difficulty in enforcing sanctions, or public opposition to changes in waste management are all factors that contribute to the maintenance waste discarding behaviour. The reuse behaviour of objects that have become useless is also historically attested, but has tended to disappear with the rise of the consumer society. This type of behaviour, whose valorisation is a way of reducing plastic waste abandonment behaviour, remains, however, less scientifically studied than other ways such as recycling.

Sustainable financing for municipal solid waste management in Nepal

Financing municipal solid waste (MSW) services is one of the key challenges faced by cities in developing countries. This study used plastic waste, a constituent of MSW, to explore the possibility of generating revenue for financing MSW management in the municipalities of Nepal. The results of this study suggest that plastic material recovery could generate revenue, which is equivalent to 1.38 times of the plastic-waste-related management cost when collection efficiency reaches 66.7%. An increase in 1% of recovery rate and collection efficiency could cover an additional 4.64% and 2.06% of the costs of managing plastic waste, respectively. In addition, an increase in tax on imported plastic materials could also motivate recovery of plastic waste for recycle and reuse. An additional 1% tax on plastic imports would be sufficient to cover plastic-related waste management when plastic waste recovery and collection efficiency rates are low. This plastic recovery- revenue exercise could be expanded to other materials such as paper and metal to fully understand the possibility of sustainable financing of MSW management and reducing environmental harm in developing countries like Nepal.

Deploying Municipal Solid Waste Management 3R-WTE Framework in Saudi Arabia: Challenges and Future

The need for resilience and an agile waste management system in Saudi Arabia is vital to control safely the rapid growth of its municipal solid waste (MSW) with minimal environment toll. Similarly, the domestic energy production in Saudi Arabia is thriving and putting a tremendous pressure on its huge reserves of fossil oil. Waste to energy (WTE) plants provides a golden opportunity for Saudi Arabia; however, both challenges (MSW mitigation and energy production) are usually looked at in isolation. This paper at first explores the potential of expanding the WTE energy production in the eastern province in Saudi Arabia under two scenarios (complete mass burn with and without recycling). Secondly, this study analyzes the effect of 3Rs (reduce, reuse, recycle) practices implementation in a residential camp (11,000 population) to influence the behavior of the camp’s citizens to reduce their average waste (kg/capita). The results of the 3R-WTE framework show a potential may reach 254 Megawatt (MW) of electricity by year 2030. The 3R system implementation in the camp reduced MSW production from 5,625 tons to 3000 tons of household waste every year, which is considered lower than what the surrounding communities to be produced in the same area.

Investigation of knowledge, attitude, and practice of Tehranian women apropos of reducing, reusing, recycling, and recovery of urban solid waste

This paper aimed to explore knowledge, attitudes, and practices (KAP) of women towards the municipal solid waste (MSW) management in Tehran, Iran, to provide a basis for experts and decision-makers to develop or improve practical waste management strategies. Women's contribution could markedly promote accomplishment of MSW management strategies, which has been neglected in many developing countries. A cross-sectional study was conducted in two stages: first, a random sample of 384 respondent women was selected from the 22 urban districts of Tehran, then 64 of them were randomly selected and trained face-to-face. The second phase was aimed at determining the effectiveness of face-to-face training and its impact on women's performance in waste management. In both stages, data were collected using a structured self-administered questionnaire containing 21 questions in four categories. Chi square (χ²) and Pearson correlation tests were applied to identify the association among variables. Results indicated that 69.6% and 72.9% of the women had adequate knowledge and attitude, respectively, while only 46.0% performed moderate practice on MSW management. Overall, significant association between education level, occupation, and marital status of the women with KAP towards reduction, reuse, recycling, and recovery of MSW were yielded (p < 0.05). Adequate knowledge and positive attitude did not necessarily lead to the proper practice in this study. However, face-to-face training positively affected women's practice in solid waste recycling and source separation. Conducting training programs and motivation of women by municipalities and decision-makers to elevate women's environmental performance could substantially promote MSW management strategies in developing nations.

The effect of policy instruments on rural households' solid waste separation behavior and the mediation of perceived value using SEM

Based on expectancy valence theory, people's behavior is affected by their self-perception and the external environment. In rural China, policy instruments as robust external environment factors have a strong effect on waste separation behavior (WSB). The purpose of the paper is to explore the influencing mechanism of policy instruments (infrastructure and information) on perceived value (perceived benefit and perceived cost) and waste separation behaviors. The data were collected from 689 rural households of Shaanxi province in China, and analyzed by using structural equation model (SEM). According to the results, the mediation effect proves that policy instruments not only can affect WSB directly but also can affect it indirectly through the perceived value. Specifically, information and infrastructure influence the perceived benefit positively and the perceived cost negatively, and information and infrastructure have an indirect effect on WSB through the mediation effect of the perceived cost. Second, policy instruments have a stronger effect on rural people's waste separation behavior than perceived value. Specifically, infrastructure has the most important impact on waste separation behavior, followed by information and then perceived cost. Third, the perceived cost is significantly negatively related to WSB, and perceived benefit has a positive effect but is statistically insignificant. It has a practical implication for the government. Providing sufficient infrastructure and launching effective information activities could improve the perceived benefit including biospheric, egoistic, social-altruistic, and reputation; and reduce the perceived cost of time, physical, learning, and money, which could then induce rural households to engage in WSB.

Development and psychometric evaluation of waste separation beliefs and behaviors scale among female students of medical sciences university based on the extended parallel process model

Background

The increasing production of un-recycled waste is a great threat to public health. Therefore, assessment and measurement of people’s beliefs and perceptions with regard to these threats can contribute to the development of suitable educational messages promoting waste separation behaviors. This study aimed to carry out the scale development and psychometric evaluation of behaviors and beliefs associated with waste separation among female students.

Method

This methodological research was performed in 2019. The primary questionnaire was developed based on the assessment of waste separation beliefs and behaviors based on the extended parallel process model. Afterwards, to confirm the content and face validity of the research tool, the opinions of 14 faculty members and certain students were asked for, respectively. In order to assess the construct validity of the questionnaire, exploratory factor analysis was performed based on the data collected from 386 female students in Isfahan University of Medical Sciences, Iran. The internal and external reliability of the tool was determined through estimating Cronbach’s alpha and test-retest based on intraclass correlation (ICC) index, respectively.

Results

The mean age and academic semester of the students were 22 ± 1.9 years and 5.58 ± 2.6, respectively. The primary version of the questionnaire was designed with 65 items; one item was omitted during the content validity process. Construct validity with factor analysis technique yielded nine dimensions including 64 items with a factor loading above 0.3. The overall reliability of the research tool was confirmed at Cronbach’s alpha of 0.87. Furthermore, the ICC of the entire questionnaire was 0.89.

Conclusion

According to the results of the study, the final 64-item questionnaire could be used by various researchers to assess waste separation beliefs and behaviors considering suitable psychometric features.

Sustainability Evaluation of Municipal Solid Waste Management System for Hanoi (Vietnam)—Why to Choose the ‘Waste-to-Energy’ Concept

According to decision no. 491/QD-TTg signed in 2018 by the Vietnamese Prime Minister approving adjustments to the national strategy for the general management of solid waste until 2025 with a vision toward 2050, Vietnam has committed itself to move toward collecting, transporting, and treating 100% of non-household waste by 2025 and 85% of waste discharged by households by 2025. This paper aims to determine which is the best sustainable solid waste management system out of those that have been formulated by World Bank experts for Hanoi until 2030 for implementing the national strategy. The paper compares four distinct solid waste management enhancement alternatives, namely, “Improving the current system for waste collection and transportation”; “Reducing, reusing, and recycling waste at source”; “Mechanical–biological treatment (MBT) plants for classifying, composting, and refuse-derived fuel (RDF) for the cement industry”; and “MBT plants for classifying, composting, and RDF for waste-to-energy/incineration plants”. The comparison was made using an analytic hierarchy process. As a result, the research indicated that “MBT plants for classifying, composting, and RDF for waste-to-energy/incineration plants” has the highest ranking in terms of a sustainable solution for the municipal solid waste management system. Therefore, it should be applied for managing the current situation in Hanoi. At the same time, the sustainable development of the system must seek to decrease the waste-to-energy ratio continuously and significantly through the planned reuse of materials that can be recycled to industry. According to the literature, in major cities in Asia and Africa, development programs are moving toward waste-to-energy solutions. The EU’s circular innovation programs and action plan may be in the opposite direction to this trend.

Performance comparison of a MSW settlement prediction model in Tehran landfill

The municipal solid waste (MSW) landfills experience a large post-closure settlement over time. Waste settlement significantly impairs utilities, structures, and the other facilities constructed on top of a landfill. This study presents the settlement mechanisms and the methods of estimating MSW landfill settlements. Since the waste materials exhibit engineering properties which vary depending on many factors such as the location, time, climate, this study also presents the data related to the landfill characteristics, waste composition, waste moisture content, and other physical and chemical properties of waste. In addition, this paper discusses the findings of a settlement investigation conducted at a municipal solid waste landfill in Tehran. In this research, based on the collected field data and data obtained from the available literature, a technical management tool for MSW closed landfills has been developed using MATLAB, which aims to predict time dependent settlement under self-weight and surcharge loads in landfills considering various related parameters, leachate, gas generation, and moisture distribution, coefficients of compression, whilst it calculates different properties of wastes, and determines the landfill slope stability under various conditions. This user-friendly program captures the variation of the model parameters with time. The results of the verification process indicate that the results from the technical management tool have been in a very good agreement with the measured field settlement data, collected from Tehran landfill. Moreover, the results of sensitivity analysis of the model in regard to variation of input parameters indicate that there are two prominent characteristics, having significant impacts on the overall landfill settlement. These characteristics are the landfill height and the compressibility parameters. The outcomes of this study can improve the confidence for design and construction on MSW landfills. It may reduce the uncertainty when predicting the landfill settlement and enable to apply the landfill redevelopment techniques more effectively and efficiently. Studying the creep settlement properties under the co-effect of stress, biodegradation and temperature for predicting the total landfill settlement is recommended for future studies.

Community Health Survey of Residents Living Near a Solid Waste Open Dumpsite in Sabak, Kelantan, Malaysia

The management of waste materials is a serious problem worldwide, especially in urbanizing countries like Malaysia. This study was conducted to compare the prevalence of health symptoms and diseases diagnosed among residents exposed to the solid waste open dumpsite in the suburb of Sabak with the non-exposed community. Research related to exposure to solid waste dumping with complete health problems has never been combined in one study. A comparative cross-sectional study was conducted. The exposed group included residents within a 1 km radius and the non-exposed group included residents between a 2.5 and 4.0 km radius from the dumpsite. The selected residents were interviewed using validated, structured questionnaires. A total of 170 residents from the exposed group and 119 residents from the non-exposed group were selected. The mean (SD) duration time of residence was 22.6 (18.9) years for the exposed group and 15.0 (12.0) years for the non-exposed group. Dumpsite exposure was significantly associated with sore throat (adjusted odd ratio (AOR) 1.88; 95% confidence interval (CI): 1.05, 3.38; p = 0.031), diabetes mellitus (AOR 2.84; 95% CI: 1.10, 7.30; p = 0.021) and hypertension (AOR 2.56; 95% CI: 1.27, 5.13; p = 0.006). This study provides evidence that the unsanitary solid waste disposal in Malaysia is hazardous to the health of residents in the surrounding 1 km, and efforts are needed to minimize the hazards.

Effects of ZnO/TiO2 nanoparticle and TiO2 nanotube additions to dense polycrystalline hydroxyapatite bioceramic from bovine bones

OBJECTIVES

A bovine dense hydroxyapatite ceramic (HA) was produced as new biomaterial, however, the production of a material with consistently high flexural strength remains challenging. The objective of this study was to evaluate the effects of ZnO nanoparticles, TiO₂ nanoparticles, and TiO₂ nanotubes (1%, 2%, and 5% by weight) on the microstructure and flexural strength of a bovine dense hydroxyapatite ceramic (HA).

METHODS

Discs (Ø=12.5mm; thickness=1.3mm) were prepared and subjected to X-ray diffraction (XRD), and observation with a field emission scanning electron microscope (FE-SEM), biaxial flexural strength (BFS) testing, and Vickers hardness (VH) testing. The BFS and VH data were subjected to ANOVA and Tukey post-hoc tests (α=0.05) and Weibull analysis.

RESULTS

The XRD showed that the addition of nanomaterials caused the formation of a secondary phase when 5% of the ZnO nanoparticles was used, or when all percentages of the TiO₂ nanoparticles/nanotubes were used, and the HA crystallographic planes were maintained. Differences were not observed between the higher BFS values obtained with pure HA and those obtained with the 5% addition of TiO₂ nanoparticles. However, the results were different compared with the other groups (α=0.05). The results obtained by Weibull analysis revealed that the 1%, 2%, and 5% addition of TiO₂ nanotubes, and the 1% and 2% addition of TiO₂ nanoparticles decreased the HA characteristic strength (σ₀), while the Weibull modulus (m) increased when 5% of TiO₂ nanoparticles, 1% and 2% of ZnO nanoparticles, and 2% of TiO₂ nanoparticles were added, but with no statistical difference from the pure HA. The 5% addition of ZnO₂ nanoparticles decreased the σ₀ without changing m. Moreover, the 5% addition of TiO₂ nanoparticles resulted in an m closest to that of pure HA. Regarding the VH results, the blend of HA with 1% and 2% addition of TiO₂ nanoparticles exhibited the higher values, which were similar between the different addition ratios (p=0.102). Moreover, the addition of 5% TiO₂ nanoparticles resulted in higher value compared with pure HA.

SIGNIFICANCE

This study demonstrated that the HA blend with 5% of TiO₂ nanoparticles has the greatest potential as a bovine HA dense bioceramic reinforcement.

New Policy and Implementation of Municipal Solid Waste Classification in Shanghai, China

To promote sustainable development, the Chinese government launched a new municipal solid waste (MSW) classification strategy in 2017. Shanghai was selected as one of the first pilot cities for MSW classification. The Shanghai municipal government first established the new MSW classification policy in 2017. The Shanghai Municipal Solid Waste Management Regulation was published in 2019 and came into effect on 1 July 2019. This short communication reports on Shanghai's new MSW classification policy and its implementation. The main content and measures adopted by Shanghai's government to ensure the effective implementation of the new MSW classification policy are introduced. Besides, a SWOT (i.e., strengths, weaknesses, opportunities, and threats) analysis on the present policy and measures is conducted, and based on the results, some discussions and suggestions regarding the implementation of MSW classification in Shanghai and the whole of China are presented.

Sustainability Indicators Concerning Waste Management for Implementation of the Circular Economy Model on the University of Lome (Togo) Campus

The circular economy aims to reduce the volume of waste generated in the world, transforming it into resources. The concept of indicator of circular economy was introduced to evaluate the improvement obtained regarding efficiency in terms of reduction, reuse and recycling of waste generated on the campus of the University of Lome (Togo). These indicators showed that 59.5% of the waste generated on the campus in 2018 could be introduced into the circular economy paradigm through composting, and 27.0% of the energy consumed could be replaced by clean energy obtained from biogas. The entire plastic fraction can be introduced into the circular economy paradigm by reusing plastic bottles and selling the rest in the port of the city. Thus, the income obtained could range from €15.5/day in 2018 to €34.5/day in 2027. Concerning old tires, 1.5% of the rubber needed to pave the entire roadway of the campus could be replaced by the waste generated by the tires currently existing there. Consequently, waste management on the campus could be controlled thanks to these indicators, and this could serve as a model for the rest of the country.

Improving Municipal Solid Waste Collection Services in Developing Countries: A Case of Bharatpur Metropolitan City, Nepal

Municipal solid waste management is one of the major challenges that cities in developing countries are facing. Although waste collection services are critical to build a smart city, the focus of both scholarship and action/activism has been more on the utilization of waste than on collection. We devised a choice experiment to elicit the preferences of municipal residents with regard to the various attributes of solid waste collection services in the Bharatpur Metropolitan City of Nepal. The study showed that households identify waste collection frequency, timing of door-to-door waste collection services, and cleanliness of the streets as the critical elements of municipal waste collection that affect their welfare and willingness to pay. While almost all households (95%) were participating in the waste collection service in the study area, more than half (53%) expressed dissatisfaction with the existing service. Women were the main actors engaged in waste collection and disposal at household level. The results of the choice analysis suggest that households prefer a designated waste collection time with waste collection bins placed at regular intervals on the streets for use by pedestrians who often throw garbage on the streets in the absence of bins. For these improvements, households were willing to pay an additional service fee of 10–28% on top of what they were already paying. The study also finds that municipal waste collection can be improved through the involvement of Tole Lane Committees in designing the timing and frequency of the service and by introducing a system of progressive tariffs based on the number of storeys per house.

Towards a Circular Economy: A Case Study of Waste Conversion into Housing Units in Cotonou, Benin

Cotonou is the largest city and main economic centre of the nation of Benin, Africa. Following independence, the city has experienced major population growth resulting in the extensive development of slums on flood plains and marshes causing the loss of biodiversity of these fragile ecosystems. Infrastructural development, unable to keep pace with informal settlement development, and a cumbersome municipal service system, have led to the illegal dumping of organic and plastic wastes, and extensive land pollution. In addition, due to its primary dune coastal location, Cotonou is facing sea level rise risks demonstrating the urgent need to sustainably address urban development. Through a socio-technical framework, this paper considers the use of transformed plastic wastes as new settlement building blocks to reduce solid waste, create jobs, and develop low-cost housing. This new strategy offers employment empowerment and a strategy to generate an income of US$2,380,000 per annum and the creation of 3200 permanent jobs.

Network Design for Municipal Solid Waste Collection: A Case Study of the Nanjing Jiangbei New Area

Garbage collection is an important part of municipal engineering. An effective service network design can help to reduce the municipal operation cost and improve its service level. In this paper, we propose an optimization model for the network design of municipal solid waste (MSW) collection in the Nanjing Jiangbei new area. The problem was formulated as a mixed integer nonlinear programming (MINLP) model with an emphasis on minimizing the annual operation cost. The model simultaneously decides on the optimal number of refuse transfer stations (RTSs), determines the relative size and location for each RTS, allocates each community to a specific RTS, and finally identifies the annual operation cost and service level for the optimal scenario as well as other scenarios. A custom solution procedure which hybrids an enumeration rule and a genetic algorithm was designed to solve the proposed model. A sensitivity analysis was also conducted to illustrate the impact of changes in parameters on the optimality of the proposed model. Test results revealed that our model could provide tangible policy recommendations for managing the MSW collection.

Evaluating the Efficiency of Municipal Solid Waste Management in China

Poor public health is always associated with the mismanagement of municipal solid waste (MSW). Many cities are besieged by MSW in the world. It is essential to do a good job in MSW management (MSWM). In order to improve the efficiency of MSWM, the Chinese government has intensively implemented relevant policies. There are still few studies on MSWM efficiency in China. The research aims to comprehensively analyze MSWM efficiency, find high-efficiency MSWM policy implementation routes and the breakthrough on improving MSWM efficiency. To measure Chinese MSWM efficiency accurately, this paper introduced the three-stage data envelopment analysis (DEA) model into the research. According to the results of DEA, Fuzzy c-Means algorithm was used to the cluster analysis of 33 typical cities. After eliminating the interference of the external environment and random disturbance, the mean value of MSWM efficiency declined from 0.575 to 0.544. The mean of pure technical efficiency (PTE) was declined from 0.966 to 0.611, while the mean of scale efficiency (SE) increased from 0.600 to 0.907. The PTE of central and northeastern cities was relatively low. The SE of western cities was comparatively high and the efficiency distribution of the eastern region was relatively scattered. In general, MSWM efficiency is low and expected to be improved. Regional differences in MSWM efficiency have been shown. The management effectiveness of eight pilot cities (MSW classification) is affirmative but not that significant. To improve MSWM efficiency, differential management for four types of cities should be carried out.