Search Results (22)

Waste is a complex challenge that requires collaboration between multiple stakeholders to achieve a circular economy. In this context, there is a growing demand for digital solutions that integrate physical and digital infrastructure to create digital waste governance systems. Analog management, without accurate data, is becoming increasingly unfeasible in light of the UN Sustainable Development Goals. Tools such as online geographic information systems (WebGIS) allow the collection and integration of large volumes of physical and human data and the establishment of a digital governance structure that brings together different technologies, tools and methods in the same environment. This article aims to present the State of the Art on the topics of zero-waste cities, WebGIS, and disruptive innovation. The article starts from the hypothesis that only a process of disruptive and systemic innovation in the value chain and urban solid waste management (MSWMS), supported by the principle of zero-waste cities, circular economy and webGIS, can effectively help to solve this problem. The research uses an exploratory literature review on the concepts of zero-waste cities, systemic innovation and webGIS applied to waste management, linking them to the theoretical framework of sustainability as a science and to Brazilian public policies, such as the National Solid Waste Policy (Law 12.305/2010), the National Circular Economy Policy (Law 1.874/2022) and the National Digital Government Strategy of Brazil 2024–2027 (ENGD). As a result, scientific publications on zero-waste cities increased from 2018 to 2023 and several countries have adopted zero-waste guidelines in waste management policies. WebGIS, remote sensing, geoprocessing and different technologies are increasingly being incorporated into waste management, generating significant impacts on the diversion of resources from landfills, mitigating climate change, and generating and/or adding value to the useful life of waste and garbage resources, in addition to the optimization and efficiency of collection operators and citizen engagement in public policies. Disruptive innovation has proven to be a concrete process to enable the transition from obsolete sociotechnical systems (such as the linear economy), where sustainable finance and environmental entities play a fundamental role in orchestrating and coordinating the convergence of private, public and civil society actors towards this new sustainable development paradigm. The case study proved to be fruitful in proposing and encouraging the adoption of such methods and principles in municipal waste management, allowing us to outline a first conception of a digital government structure and digitalization of public services for zero-waste cities, as well as pointing out the difficulties of implementing and transforming these systems. This digital governance structure demonstrates the possibility of being replicable and scalable to other cities around the world, which can materialize an important tool for the implementation, articulation and development of a long-term sustainable development paradigm, based on the vision of the circular economy and zero-waste cities. Full article

The increase in global municipal solid waste (MSW) generation, with a significant portion being improperly managed, has resulted in detrimental socio-ecological effects. This paper addresses the challenge of implementing effective waste management practices for achieving sustainability, particularly in urban areas where the majority of global waste is generated. It emphasizes the need for a multidimensional, multiscale, and long-term approach that surpasses local solutions and linear strategies. The approach recognizes the broader impacts of waste management beyond city boundaries and promotes circularity by incorporating waste reduction, reuse, recycling, and proper disposal practices. Through an analysis of the literature on waste from 1992 to 2022, this paper aims to identify the key concepts, propose solutions, and explore sustainable waste management scenarios. This paper introduces the m-SWM4Cities model for sustainable waste management in urban areas, highlighting its methodology and application in Mexico City (mD-SWM4CDMX). The models presented in this paper incorporate essential elements and interactions, providing a comprehensive understanding of the transition to sustainable waste management. The findings highlight the importance of monitoring waste management indicators and offer insights into the waste system of Mexico City. The m-SWM4Cities model can be adapted to address specific city contexts and thus serves as a valuable tool for assessing and improving waste management practices. Full article

As the environment reaches field capacity and is unable to regenerate waste naturally, challenges resulting from municipal solid waste management (MSWM) are showing a global increase, especially in developing countries. Nigeria is a country with a huge quantity of municipal solid waste (MSW) without a functional and operational MSWM system. This systematic review of the literature (SLR) aimed at investigating knowledge application in view of the circular economy (CE) model in the management of MSW in Nigeria, while answering research questions on the adoption and implementation of the circularity principle. In line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol, a comprehensive search strategy was developed to source electronic versions of updated articles from the Scopus, Web of Science, and Sage databases. The search retrieved 476, 878, and 374 results, respectively. The search was limited to publications written in the English language between 2008 and 2022 and was downloaded via Endnote and screened using Rayyan.ai. The SLR was conducted between February and October 2022. Findings revealed some potential opportunities for the transition and implementation of CE by identifying major indicators and enablers, but pointed out some barriers, including weak legislation, poor funding, the non-engagement of professionals, the absence of infrastructure, a lack of strategic planning, uncivilized behavioral conduct, and demography. The need to improve the current practice of MSWM from the linear economy (LE) of take–make–dispose is crucial. Summarily, the transition towards CE in MSWM is feasible and it can be initiated through the application of the 3Rs and 12Rs while anticipating the provision of infrastructural and novel technologies for a functional MSWM framework. Full article

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. Full article

Since the publication of the Guidelines for Social Life Cycle Assessment (S-LCA) of Products by the United Nations Environment Programme (UNEP) and the Society of Environmental Toxicology and Chemistry (SETAC) in 2009, there has been an increase in publications and research using this tool to assess the positive or negative social impacts of products and services. This can be done by assessing all processes in the material supply chain, thereby identifying and quantifying the respective social impacts to inform decision makers. Because raw materials can come from different countries, some production processes may use recyclable or reusable materials handled by waste pickers in order to return them to the production chain. Since these waste pickers earn their living from collecting and selling these materials, the social impacts of the final product integrate the social evaluation results of the processes involving these materials. Thus, this article aims to survey the characteristics of current S-LCA models applied to Municipal Solid Waste Management Systems (MSWMS) that include waste pickers and their organizations, in order to identify research opportunities to expand the understanding and application of this tool. In this study, 33 articles were selected, using a systematic review methodology. Analyzing these articles has revealed possible paths to improve the choice of elements for S-LCA models applied to MSWMS that involve waste pickers or equivalents. Full article

Population in cities is growing worldwide, which puts the systems that offer basic services to citizens under pressure. Among these systems, the Municipal Solid Waste Management System (MSWMS) is also affected. Waste collection and transportation is the first task in an MSWMS, carried out traditionally in most cases. This approach leads to inefficient resource and time expense since routes are prescheduled or defined upon drivers’ choices. The waste collection is recognized as an NP-hard problem that can be modeled as a Capacitated Waste Collection Problem (CWCP). Despite the good quality of works currently available in the literature, the execution time of algorithms is often forgotten, and faster algorithms are required to increase the feasibility of the solutions found. In this paper, we show the performance of the open-source Google OR-Tools to solve the CWCP in Bragança, Portugal (inland city). The three metaheuristics available in this tool were able to reduce significantly the cost associated with waste collection in less than 2 s of execution time. The result obtained in this work proves the applicability of the OR-Tools to be explored for waste collection problems considering bigger systems. Furthermore, the fast response can be useful for developing new platforms for dynamic vehicle routing problems that represent scenarios closer to the real one. We anticipate the proven efficacy of OR-Tools to solve CWCP as the starting point of developments toward applying optimization algorithms to solve real and dynamic problems. Full article

Municipal solid waste (MSW) classification is a national strategic objective and an important component of successful municipal solid waste management (MSWM). Some failures of pilot programs suggest that safeguarding measures are essential for MSW classification. A questionnaire survey of public awareness and attitudes toward MSW source-separated collection in Chongqing’s main districts was conducted, and the results indicated that the proportions of respondents willing to participate in MSW classification and provide money for it were 67.9% and 86.2%, respectively. The positive impacts of the overall-process management measures on promoting MSW classification in Chongqing’s main districts, including source-separated collection system, transportation system, treatment and disposal system, and environmental sanitation prevention system, were analyzed comprehensively. The analyses revealed that a 98% resident participation rate was obtained for MSW source-separated collection with the application of a cloud-based platform and traceability system. Moreover, the secondary transportation and comprehensive “4 + 1” (four waste incineration plants and one waste landfill) disposal mode showed significant advantages with respect to costs and environmental friendliness. In view of the environmental sanitation risks, the prevention and control of environmental sanitation were developed in Chongqing. The future prospects have also been discussed. The refinement and regionalization of source-separated collection are proposed as the possible solution. Full article

Life cycle assessment (LCA) tools can be used for the environmental assessment of municipal solid waste management (MSWM) systems. The present study aims to evaluate the impact of an MSWM system in Riyadh, Saudi Arabia, under three different scenarios based on the Strategy for 2045 of Riyadh. The current scenario (S0) considers that municipal solid waste (MSW) is landfilled, scenario one (S1) considers waste to energy (WtE) as the main treatment while dry recyclables and organic waste collection schemes are introduced, and scenario two (S2) considers dry recyclables and organic waste collection schemes at the maximum level while the residual portion is treated as WtE. The system boundaries include MSW treatment and disposal by recycling, incineration, composting, and landfilling methods. The scenarios were compared using SimaPro 9.1.1.1 software, and the ReCiPe 2016 Midpoint (H) V1.04/World (2010) H method was used to assess global warming, ozone formation (human health), fine particulate matter formation, terrestrial acidification, freshwater eutrophication, mineral resource scarcity, and fossil resource scarcity. S0 was found to be the scenario with the least impact if considering just the waste treatment. However, S1 and S2 allow material and energy recovery that avoids the impact of obtaining primary resources. S1 and S2 reduced greenhouse gases (GHG) emissions by 55% and 58%, respectively, compared to S0. According to the SV2030, 2% of the electricity generated by the Kingdom would have to come from WtE, but based on the calculations, the maximum electricity from waste would be obtained with S1 fully implemented and would contribute a maximum of 1.51% to Saudi Arabia’s electricity demand. This study contributes by providing useful insights that could help decision-makers to understand the potential environmental impacts by assessing each step considered by the Strategy for 2045 for Riyadh along with the consequences on material and energy supply by using the material and energy potential of MSW. Full article

Municipal solid waste management (MSWM) systems in developing countries adopt practices from developed countries to reduce their environmental burdens. However, several complex issues specific to developing countries hinder the full implementation of these practices. The future of MSWM in Davao City, Philippines, is envisaged as a notable example of the combination of new infrastructure and local MSWM practices. A linear programming model was developed, following material flow analysis and life cycle assessment, to design an optimal system for Davao City. The performance of the system was evaluated in terms of greenhouse gas emissions, energy and revenue generated, and the amount of landfill waste. The results show that the proposed system positively affects the environment compared to the current system, due to additional treatment options. However, the main allocation concern transitions from organic waste in the current system to plastic waste in future scenarios. Furthermore, the mitigation of greenhouse gas emissions and the extension of landfill life will be heavily influenced by trade-offs between sorting operations and the management of incinerated wastes with high calorific values. Therefore, plastic-waste-specific treatment options will be critical for future MSWM systems. The results herein underscore the need for sustainable MSWM in the study area, considering the region-specific conditions. Full article

In China, environmental pollution due to municipal solid waste (MSW) over-generation is one of the country’s priority concerns. The increasing volume and complexity of the waste poses serious risks to the environment and public health. Currently, the annual growth of MSW generation is estimated to be approximately 8–10% and will increase to 323 million metric tons (Mt) by 2030. Based on the secondary data collected from a literature survey, this article critically evaluates the recent progress of MSW management (MSWM) in China and offers new insights into the waste sector in the era of Industry 4.0. This helps decision makers in China to plan a smooth transition nationwide to a circular economy (CE) in the waste sector. It is evident that digitalization is a driving force for China to move towards low-carbon development strategies within the framework of CE. Through digitalization, the waste sector has promoted prevention, reduction, reuse, and recycling (3Rs) of waste before waste disposal in landfills. A proper implementation of digitalization-based waste recycling has contributed to an efficient cooperation between the government and private sector, increased job opportunities, and promoted the conservation of resources. It is anticipated that this work not only contributes to the establishment of an integrated MSWM system in China, but also improves local MSWM through digitalization in the framework of a CE. Full article

In recent years, there has been a trend of increasing criticism towards official development assistance (ODA) and the optimization of ODA policies, in a world of growing inequality between the Global North and Global South. To contribute to efficient ODA planning, this article proposes to innovatively apply system dynamics as an optimal tool for ex ante impact assessment. The study case is located in the slums of Darkhan (Mongolia), whose citizens and environment suffer the consequences of poor urban planning and lack of municipal solid waste management (MSWM). In this context, the present research proposes a policy of education and infrastructure as key factors for the improvement of MSWM in the context of an international cooperation plan, carried out by the Korean agency KOICA. To evaluate its impact and anticipate its effects, a tailor-made system dynamics model of a Darkhan district has been created, with the focus on the education process in order to simulate the different options of the proposed policies. The results show that education policy is particularly relevant for behavioral change, in terms of reducing waste burned and waste on the ground, and increasing composted and recycled waste. However, in this context, the policy is ineffective for improving the district’s water and air pollution situation. This article also offers discussions and recommendations to be applied to the international cooperation plan, which takes place in real life. It is expected that the described process of model construction and its results will contribute to the further use of system dynamics as a planning tool in the international cooperation field. Full article

Municipal solid waste management (MSWM) has become a major challenge in Sri Lanka for post-conflict development activities. Many urban areas are facing severe problems in managing 10 to 50 metric tons of waste per day. However, limited research has been carried out to identify the key issues and policy gaps in MSWM. This research studies the existing complexities of MSWM processes, practices, and emerging challenges in three highly congested urban areas in the south-eastern coast of Sri Lanka. A mixed method strategy using field observations, semi-structured interviews and secondary data sources was employed for the data collection. The study revealed that, although the MSWM systems in the urban areas include all necessary elements, their effectiveness and efficiency are not satisfactory due to poor or non-segregation of waste at the source of generation; lack of resources; absence of regulation to reduce waste generation and control polluters; absence of regular collection schedule; and lack of technical know-how and initiatives. The recommendations drawn from the study include feasible solutions and immediate measures required to improve the MSWM before the related environmental and public health problems become a social catastrophe. The recommendations will also greatly contribute in the achievement of developing sustainable cities. Full article

Confronted with a series of problems caused by surging generation of municipal solid waste (MSW), the Chinese central and local governments have promulgated and implemented policies to deal with them, including promotions of the classification of MSW. However, to date, practical knowledge and understanding about benefits for garbage classification from its environmental performance perspective is still limited. The present study is purposed to comprehensively investigate the environmental effects of garbage classification on municipal solid waste management (MSWM) systems based on three proposed garbage classification scenarios in China, via a comparative life cycle impact assessment (LCIA). Taking advantage of Impact Assessment of Chemical Toxics (IMPACT) 2002+ method, this comparative LCIA study can quantitatively evaluate midpoint, endpoint, and single scored life cycle impacts for the studied MSWM systems. A Monte Carlo uncertainty analysis is carried out to test the effectiveness and reliabilities of the LCIA results. The LCIA and uncertainty analysis results show that MSWM systems based on various garbage classification scenarios have significant variations in the studied midpoint, endpoint, and single scored environmental impacts. Different garbage classification scenarios have their individual environmental-friendly superiority for specific impact categories. Overall, results of this study demonstrate that MSW treatment systems integrated with garbage classification are more environmentally friendly by comparison with non-classification; and that the more elaborate the level of MSW classification, the smaller its impacts on the environment. Full article

Mexico City generates 12 thousand tons of Municipal Solid Waste (MSW) per day, which places it as one of the cities that produces the most MSW in the world. However, the treatments used in the city are not enough for recycling materials and organics valorization of at least 45% of the MSW, which is the minimum for a medium-high-income city. To put in a global context the deficiency in Municipal Solid Waste Management (MSWM) in Mexico City and evaluate the policies that have been implemented thus far, Wasteaware benchmark Indicators for Integrated Sustainable Waste Management (ISWM) were used to obtain a desired profile for the comprehensive MSWM in Mexico City. The Wasteaware Benchmark Indicators have been tested in more than 50 cities around the world. The results showed that in Mexico City, certain aspects of governance present the most considerable delay and, at the same time, that there are certain areas of opportunity to improve the efficiency of MSWM in its physical aspects, such as collection systems or treatment services. Full article

Six municipal solid waste management (MSWM) options (A1–A6) in Harare were developed and analyzed for their global warming, acidification, eutrophication and human health impact potentials using life cycle assessment methodology to determine the least impactful option in Harare. Study findings will aid the development of future MSWM systems in Harare. A1 and A2 considered the landfilling and incineration, respectively, of indiscriminately collected MSW with energy recovery and byproduct treatment. Source-separated biodegradables were anaerobically treated with the remaining non-biodegradable fraction being incinerated in A3 and landfilled in A4. A5 and A6 had the same processes as in A3 and A4, respectively, except the inclusion of the recovery of 20% of the recoverable materials. The life cycle stages considered were collection and transportation, materials recovery, anaerobic digestion, landfilling and incineration. A5 emerged as the best option. Materials recovery contributed to impact potential reductions across the four impact categories. Sensitivity analysis revealed that doubling materials recovery and increasing it to 28% under A5 resulted in zero eutrophication and acidification, respectively. Increasing material recovery to 24% and 26% under A6 leads to zero acidification and eutrophication, respectively. Zero global warming and human health impacts under A6 are realised at 6% and 9% materials recovery levels, respectively. Full article