چكيده به لاتين
The growing rate of urbanization and, consequently, the increase in waste production clarifies the necessity of the reuse of generated wastes. Unfortunately, mainly in developing countries, generated waste is disposed directly without being reused. In order to maintain the quality of the generated waste, it is better to source-separate the waste by households, which requires education and high costs. Due to the lack of waste segregation by all households, in the proposed model of this dissertation, two separate streams have been used, one for segregated waste and the other for mixed waste. Also, for designing the municipal solid waste network, a four-level supply chain has been considered, which contains: production and collection points, intermediate transfer stations, waste processing facilities, and landfills. To model this supply chain, a sustainable mathematical model with economic, environmental, and social objective functions have been used, which are the costs of the waste management network, greenhouse gas (GHG) emissions from network activities, and social scores, respectively. The social objective function consists of four elements which are taxation, education, job creation, and facility pollution. Creating a social objective function with the ability to quantify the social welfare of citizens can be named as a major contribution of this dissertation. The proposed model is able to assist decision-makers in determining the optimal rate of source-separation that optimizes the educational costs, the optimal location and technology of each facility, the optimal amount of allocation to each facility, and the optimal type and number of trucks in the transportation fleet. Also, to make the model more realistic, it ensures the compatibility between waste type and facility’s technology. Furthermore, the model considers the types of products produced from each of the waste processing facilities. The proposed model is implemented on a data set collected from Tehran, Iran. To obtain the Pareto set, the goal programming method has been used, and the most desirable solution has been selected by the TOPSIS method. Based on the obtained solution, in order to create job opportunities, the model has activated all intermediate transfer stations, two composting facilities, two waste incineration facilities, a recycling plant, and two treatment centers. Also, by comparing the proposed model with the current situation model, the proposed model was able to make significant improvements in all three objective functions.
