RESUMEN
Waste electrical and electronic equipment is one of the essential pollutants with significant negative impacts on the environment and human health. In this study, a multi-period mixed-integer linear programming model is developed to design a closed loop supply network for the management of electrical and electronic equipment by explicitly considering the economic and environmental sustainability with a budget constraint. Different recycling options like refurbishing, disassembling, remanufacturing, and disposal centers are considered in the design of the network. The model minimizes the total costs of the network and the total carbon emission tax. The literature review shows that the introduced model is more comprehensive than the other existing models because it simultaneously determines the location of facilities, the capacity of facilities, type of manufacturing technologies, variety of vehicles, and the allocation and transportation of materials and products. The model was applied to a real-life case study in Iran and could provide a profit of IRR 245,509,165 M during the planning periods. The carbon tax policy with different echelons is applied to control the environmental impacts in which the carbon tax increases as carbon emissions increase. The results show a nearly linear relationship between the total costs of the network and the carbon tax. The carbon tax of equal to or more than 10,800 IRR/t CO2 can be a deterrent factor for the electrical and electronic equipment manufacturer in Iran to diminish emissions through investment in green technologies.
Asunto(s)
Carbono , Ambiente , Humanos , Costos y Análisis de Costo , Electrónica , PolíticasRESUMEN
Daily transportation of wastes due to its environmental, financial, and social aspects has been considered a challenging issue in developing countries' municipal solid waste management systems. The location of transfer stations as intermediate nodes in municipal solid waste management network affects optimal collection frequency. A sustainable multi-period and multi-trip vehicle routing problem integrated with relocation models was developed to redesign the intermediate transfer stations and find optimal vehicle routes and the best collection frequency for each municipal solid waste generation point. Regarding the social aspects of a sustainable solid waste management system, an extended social life cycle assessment methodology for redesign and routing operations was developed based on the UNEP guidelines. The social life cycle assessment methodology evaluated the probable social effects of the system throughout the entire life cycle using an iterative policy. In this study, selected impact subcategories and inventory indicators for the routing and redesign system were utilized to quantify the system social score. Besides, the developed model was solved for different problem instances. The results indicated that system social score was affected by collection frequencies decisions, redesign policy, and the number of demand nodes. Furthermore, the model was applied to a real-world case study resulting in a total cost reduction of 66% that occurred by a 86% reduction in weekly traveled distance and a 12% decrease in routing social score.
Asunto(s)
Eliminación de Residuos , Administración de Residuos , Ciudades , Irán , Eliminación de Residuos/métodos , Residuos Sólidos , TransportesRESUMEN
The efficient management of municipal solid waste is a major problem for large and populated cities. In many countries, the majority of municipal solid waste is landfilled or dumped owing to an inefficient waste management system. Therefore, an optimal and sustainable waste management strategy is needed. This study introduces a recycling and disposal network for sustainable utilisation of municipal solid waste. In order to optimise the network, we develop a multi-objective mixed integer linear programming model in which the economic, environmental and social dimensions of sustainability are concurrently balanced. The model is able to: select the best combination of waste treatment facilities; specify the type, location and capacity of waste treatment facilities; determine the allocation of waste to facilities; consider the transportation of waste and distribution of processed products; maximise the profit of the system; minimise the environmental footprint; maximise the social impacts of the system; and eventually generate an optimal and sustainable configuration for municipal solid waste management. The proposed methodology could be applied to any region around the world. Here, the city of Tehran, Iran, is presented as a real case study to show the applicability of the methodology.