A robust bi-level optimization modelling approach for municipal solid waste management; a real case study of Iran

The need to implement innovative sustainable production processes is a topic of important social relevance in this current century. Environmental tragedies on different continents have revealed that humanity needs to understand how nature belongs to a system that needs to be balanced in order to maintain its existence. One of the major sustainability challenges globally is the management of solid wastes (SW). The rapid urbanization coupled with the increase in the world population has resulted in a consequential increase in the use of various products and their associated generated wastes. Of such SW that is complicated to manage are medical wastes which are deemed hazardous. Thus, the various industries including the health industry must implement a reverse logistic methodology in the disposal of solid wastes in order to efficiently and effectively manage their wastes. Countries such as Brazil, have incorporated reverse logistics into their National Solid Waste Policy (NSWP) thereby ensuring adequate disposal of various solid wastes and co-responsibility among the generators of various wastes. In this study, the strategies adopted within the scope of the Unified Health System (SUS, in Portuguese) in Brazil related to the reverse logistics of medicines consumed in the health industry were investigated. As a methodology, qualitative research such as literature review and documentary were utilized in order to obtain knowledge about the major information about the health industry in Brazil. The findings and discussions provided in this paper revealed that reverse logistics applied to pharmaceutical products in Brazil is still incipient. Although there is consolidated literature on the subject in national studies, there is a lack of evidence that indicates effective models of reverse drug logistics in the country, in a scenario of growth of 10% per year in the generation of this waste on average in the country. It is concluded that reverse drug logistics in Brazil is in an embryonic process, strengthened by the construction of regulations and laws that may encourage industries to adopt good practices in the production and management of drug wastes, and which, when implemented, can generate a reduction of around 12% in the volume generated per year.

Index to volume 5

Supplier selection is one of the intricate decisions of managers in modern business era. There are different methods and techniques for supplier selection. Data envelopment analysis (DEA) is a popular decision-making method that can be used for this purpose. In this paper, a new dynamic DEA approach is proposed which is capable of evaluating the suppliers in consecutive periods based on their inputs, outputs, and the relationships between the periods classified as desirable relationships, undesirable relationships, and free relationships with positive and negative natures. To this aim various social, economic, and environmental criteria are taken into account. A new method for constructing an ideal decision-making unit (DMU) is proposed in this paper which differs from the existing ones in the literature according to its capability of considering periods with unit efficiencies which do not necessarily belong to a unique DMU. Furthermore, the new ideal DMU has the required ability to rank the suppliers with the same efficiency ratio. In the concerned problem, the supplier that has unit efficiency in each period is selected to construct an ideal supplier. Since it is possible to have more than one supplier with unit efficiency in each period, the ideal supplier can be made with different scenarios with a given probability. To deal with such uncertain condition, a new robust dynamic DEA model is elaborated based on a scenario-based robust optimization approach. Computational results indicate that the proposed robust optimization approach can evaluate and rank the suppliers with unit efficiencies which could not be ranked previously. Furthermore, the proposed ideal DMU can be appropriately used as a benchmark for other DMUs to adjust the probable improvement plans.

PurposeWith rapid industrialization and urbanization, municipal solid waste (MSW) management has become a serious challenge worldwide, especially in developing countries. The Beijing Municipality is a representative example of many local governments in China that are facing MSW management issues. Although there have been studies in the area of MSW management in the literature, less attention has been devoted to developing a structured framework that identifies and interprets the barriers to MSW management in megacities, especially in Beijing. Therefore, this study focuses on identifying a comprehensive list of barriers affecting the successful implementation of MSW management in Beijing.Design/methodology/approachThrough an extensive review of related literature, 12 barriers are identified and classified into five categories: government, waste, knowledge dissemination, MSW management process and market. Using an integrated approach including the decision-making trial and evaluation laboratory (DEMATEL), maximum mean de-entropy algorithm (MMDE) and interpretive structural modeling (ISM), a conceptual structural model of MSW implementation barriers is constructed to provide insights for industrial decision-makers and policymakers.FindingsThe results show that a lack of economic support from the government, imperfect MSW-related laws and regulations, the low education of residents and the lack of publicity of waste recycling knowledge are the main barriers to MSW management in Beijing. Combined with expert opinions, the paper provides suggestions and guidance to municipal authorities and industry practitioners to guide the successful implementation of MSW management.Practical implicationsThe findings of this study can provide a reference for MSW management in other metropolises in China and other developing countries.Originality/valueThis study proposes a hybrid DEMATEL-MMDE-ISM approach to resolve the subjectivity issues of the traditional ISM approach and it analyzes the barriers that hinder MSW management practices in Beijing.

The proximity principle - disposing of waste close to its origin - has been a central value in municipal solid waste (MSW) management in Japan for the last 30 years and its widespread adoption has helped resolve numerous "Not in My Backyard" issues related to MSW management. However, MSW management costs have soared, in large part because of aggressive recycling efforts and because most MSW is incinerated in a country that has scarce landfill capacity. In addition, smaller, less sophisticated incinerators have been closed because of high dioxin emissions. Rising costs combined with the closure of smaller incinerators have shifted MSW management policy toward regionalization, which is the sharing of waste management facilities across municipalities. Despite the increased use of regionalized MSW facilities, the proximity principle remains the central value in Japanese MSW management. Municipal solid waste management has become increasingly regionalized in the United States, too, but different driving forces are at work in these two countries. The transition to regionalized MSW management in Japan results from strong governmental control at all levels, with the central government providing funds and policy direction and prefectures and municipalities being the primary implementing authorities. By contrast, market forces are a much stronger force with US MSW management, where local governments - with state government oversight - have primary responsibility for MSW management. We describe recent changes in Japan's MSW programs. We examine the connections between MSW facility regionalization, on the one hand, and, on the other hand, the proximity principle, coordination among local governments, central government control, and financing mechanisms.

Development of an integrated online deposition and corrosion monitoring system in a full-scale solid waste CFB boiler

The continued migration of people from rural to urban areas occurs due to the development of people. The uncontrolled growth in urban areas has left many cities deficient in infrastructural services such as water supply, sewerage, and municipal solid waste management. Municipal Solid Waste Management (MSWM) is a challenging problem in urban areas. This paper details about the waste collection system, present status of waste processing and Greenhouse gas emission of solid waste in Erode Corporation. A detailed investigation was made regarding the methods of practices associated with sources, generating quantity, collection, transportation, storage, treatment, and disposal of municipal solid waste in Erode city. The data concerning solid waste were obtained through an individual field visit, interacting with people and authentic records of the municipal corporation of Erode District. The carbon footprint of solid waste has been calculated by using theoretical and experimental method. Finally, based on the analysis, proper and more reliable suggestion has been attained for the suitable and sustainable performance of the M unicipal Solid Waste Management in Erode Corporation.

Every year, religious events (REs) attended by millions of pilgrims, take place in different holy cities around the world. However, research on municipal solid waste management (MSWM) is limited despite the reputation of REs to generate large amounts of municipal solid waste (MSW), which negatively influences the environment and human health when poorly managed. The Arba’een is one of the largest REs in Iraq and worldwide that attracts more than 11 million pilgrims annually. A large quantity of MSW is produced during this event, which is poorly managed and disposed of in a dumpsite without any treatment, due to the lack of research and data about MSW generated during such events. Thus, this research aims to address part of this gap and contribute to new knowledge on MSWM at REs by studying the MSWM system applied at the Arba’een, a subject that has never been considered before. This study adopts mixed methods research approach, employing composition analysis for MSW, questionnaire surveys and interviews with the stakeholders (hoteliers, camp owners, pilgrims and MSWM authorities) and on-site observations as key methods for generation of data. The MSWM system was assessed based on the opinion of the key stakeholders and the Wasteaware benchmark indicators formwork. Numerical models were built to estimate the quantities of MSW produced by pilgrims’ accommodation (hotels and camps) based on the characteristics of the accommodation (capacity, area etc.). MSWM services users’ (hoteliers, camp owners and pilgrims) intention to participate in a recycling scheme and the variables influence this intention were studied with a view of investigating the possibility of introducing a recycling scheme at REs. The results showed that REs account for 14% of the city’s MSW and its main components were organic (57.9%), paper (14.9%) and plastic (14.6%). The MSWM system suffers from operational and governance weaknesses; the key weaknesses are lack of controlled disposal facility, absence of a formal recycling scheme, deficit of key waste-related data, poor public involvement, inadequate planning, and funding limitations. Statistical analyses showed that average municipal solid waste generation (MSWG) from hotels and camps were 112 and 413kg.day-1, respectively. Hotels’ MSWG is influenced by their capacity, staff size and expenditure while camps’ capacity, expenditure and food services affect its MSWG. MSWG from hotels and camps can be modelled with a coefficient of determination of about 0.80. In addition, more than 65% of MSWM system users are willing to participate in MSW recycling during REs and it is expected that about one third would perform recycling; this indicates that introducing MSW recycling during REs could be successful.

Akwa Ibom state is one of the nine states in the Niger Delta region of Nigeria. This region is critical to sustainable economic development in the country being the main oil producing area. With its location within the tropical rainforest and dense population, Uyo, like other major cities in Nigeria generates enormous municipal solid waste which is not adequately managed. Municipal solid waste management has therefore emerged as one of the greatest challenges facing environmental agencies in the city. Solid waste management is simply reduced to waste transfer with overflow dump sites causing serious environmental pollution. Waste management practices are characterized by inefficient collection and poor disposal methods. Waste stream comprises: 65% of compostable materials, 10% plastics, 8% paper, 4% metal, 3% textile, 3% glass and 7% others. The rate of waste generation ranged between 0.49 to 0.60 kg/capita/day with an average of 0.54 kg/capita/day. Inadequate finances, lack of institutional arrangement, insufficient information on the quantity and quality of waste as well as inappropriate technology are the main constraints militating against effective solid waste management in Uyo. The findings in this research are useful in formulating adequate waste disposal procedures. In addition, the potential of waste recovery, reduction and reuse based on waste characteristics is projected at about $8million annually. However, further research is required in the area in order to maximize this potential.

Municipal solid waste (MSW) management currently requires critical attention in ensuring the best principles of socio-economic attributes such as environmental protection, economic sustainability, and mitigation of human health problems. Numerous surveys on the waste management system reveal that approximately 90% of the MSW systems are improperly disposing the wastages in open dumps and landfills. Classifying the wastages into biodegradable and non-biodegradable helps converting them into usable energy and disposing properly. The advancements of effective computational approaches like artificial intelligence and image processing provide wide range of solutions for the present problem identified in MSW management. The computational approaches can be programmed to classify wastes that help to convert them into usable energy. Existing methods of waste classification in MSW remain unresolved due to poor accuracy and higher error rate. This paper presents an experimented effective computer vision–based MSW management solution with the help of the Internet of Things (IoT), and machine learning (ML) techniques namely regression, classification, clustering, and correlation rules for the perception of solid waste images. A ground-up built convolutional neural network (CNN) and CNN by the inception of ResNet V2 models trained through transfer learning for image classification. ResNet V2 supports training large datasets in deep neural networks to achieve improved accuracy and reduced error rate in identity mapping. In addition, batch normalization and mixed hybrid pooling techniques are incorporated in CNN to improve stability and yield state of art performance. The proposed model identifies the type of waste and classifies them as biodegradable or non-biodegradable to collect in respective waste bins precisely. Furthermore, observation of performance metrics, accuracy, and loss ensures the effective functions of the proposed model compared to other existing models. The proposed ResNet-based CNN performs waste classification with 19.08% higher accuracy and 34.97% lower loss than the performance metrics of other existing models.

As presented in the first companion paper, distributed mixed-integer fuzzy hierarchical programming (DMIFHP) was developed for municipal solid waste management (MSWM) under complexities of heterogeneities, hierarchy, discreteness, and interactions. Beijing was selected as a representative case. This paper focuses on presenting the obtained schemes and the revealed mechanisms of the Beijing MSWM system. The optimal MSWM schemes for Beijing under various solid waste treatment policies and their differences are deliberated. The impacts of facility expansion, hierarchy, and spatial heterogeneities and potential extensions of DMIFHP are also discussed. A few of findings are revealed from the results and a series of comparisons and analyses. For instance, DMIFHP is capable of robustly reflecting these complexities in MSWM systems, especially for Beijing. The optimal MSWM schemes are of fragmented patterns due to the dominant role of the proximity principle in allocating solid waste treatment resources, and they are closely related to regulated ratios of landfilling, incineration, and composting. Communities without significant differences among distances to different types of treatment facilities are more sensitive to these ratios than others. The complexities of hierarchy and heterogeneities pose significant impacts on MSWM practices. Spatial dislocation of MSW generation rates and facility capacities caused by unreasonable planning in the past may result in insufficient utilization of treatment capacities under substantial influences of transportation costs. The problems of unreasonable MSWM planning, e.g., severe imbalance among different technologies and complete vacancy of ten facilities, should be gained deliberation of the public and the municipal or local governments in Beijing. These findings are helpful for gaining insights into MSWM systems under these complexities, mitigating key challenges in the planning of these systems, improving the related management practices, and eliminating potential socio-economic and eco-environmental issues resulting from unreasonable management.

Multiskilling with closed chains in a service industry: A robust optimization approach

ABSTRACTThe problem of municipal solid waste has remained intractable in Nigeria despite the state’s central role in municipal solid waste management (MSWM). Policy and reforms of the MSWM system have invariably excluded the informal economy, with this exclusion frequently reinforced by uncritical implementation of neo-liberal development policies. Yet, the informal economy fortuitously remains active in solid waste collection, recycling, and disposal. This article is the aggregate outcome of an 8-year multi-stakeholder engagement in MSWM in Nigerian cities. It draws on insights from first-hand qualitative engagement with informal waste workers, interviews with key stakeholders, policy documents, and relevant literature to situate the Nigerian informal waste economy within current international development discourse. While highlighting the implications of social acceptance and inclusion of the waste economy in post-2015 MSWM and development policy, the study notes the lack of an articulate policy on MSWM in Nigeria and canvasses a specific policy to integrate the ubiquitous informal waste economy in MSWM. The paper suggests that inclusion per sé is central to the sustainable development goals (SDGs), and argues that an inclusive MSWM policy in Nigeria is desirable as it maps onto the SDGs which aim to improve lives in the post-2015 development era.

Solid waste is a substantial problem, predominantly in emerging countries that lack adequate substructure and operational land mass to process it in a corrected manner. Several emerging nations are facing a combination of issues that avert proper management of solid waste. This paper reviews the management of municipal solid waste in Ethiopia, using the Addis Ababa City as a case study. The consumption of plastic materials is vast and has been growing steadily in view of the advantages derived from their versatility, relatively low cost, chemical stability, and low degradability. Some of the most used plastics are polyethylenes, which have a massive production and consumption in many applications such as packaging, building, electricity and electronics, agriculture, health care, etc. As well as The production of alternative fuels and safe waste disposal are two of the major concerns facing the world today, because both environmental concerns and energy derived from petroleum based fuels will define the future economic potential of a country. The increased demand and production of polyethylene (PE) has led to the accumulation of large amounts of it in the final waste stream. Keywords: Polyethylene, waste plastics, Solid Waste Management, Municipal Solid Waste, Opinions, Urbanizing, Developing Countries, Solid Waste, Disposal

The global outbreak of SARS-CoV-2 has spurred a reassessment of Municipal Solid Waste management strategies and approaches. A significant need for sanitation and hygiene was accentuated for disease prevention and control with the onset of the pandemic. With an alteration of the status quo in waste management system, an unprecedented amount of face masks, protective equipment, and other biological wastes was generated in the form of Municipal Solid Waste . This upsurge of potentially infected wastes originated a risk of transmission amongst frontline workers. Furthermore, the potential contamination of Municipal Solid Waste was rendered as a legitimate threat due to improper collection practices, disposal and handling of solid waste. Several novel waste disposal techniques and waste management policies were also introduced during this period. However, the sanitation-policy making-occupational safety nexus remains inadequately explored under the prevalent COVID-19 scenario. Through the prism of shifting waste composition, this review offers a global assessment of existing solid waste management systems during the COVID-19 pandemic. The physiological and psychological hazards faced by the frontline workers were explored and instances of best-case and worst-case policies on solid waste handling were recorded. Modern methods of waste disposal and latest trends of policymaking were evaluated. A model study of unsupervised learning via Partition Around Medoids cluster analysis was undertaken to reveal underlying patterns of waste management policies. Although, the clusters were formed devoid of any socio-economic parameters, this study strives to indicate proof of concept and can serve as a precursor to advanced clustering studies.