A sustainable municipal solid waste system under leachate treatment impact along with leakage control and source separation

Abstract

Over the past few decades, inefficient waste management has caused environmental problems, such as leachate leakage, high pollution in the surface and groundwater, and soil contamination. In this regard, it is essential to adopt proper pre-discharge leachate management and treatment in the case of municipal waste. This study proposes a novel sustainable network design model by determining the optimal combination of transfer stations and separation units equipped with waste compaction and leachate treatment technologies, waste treatment facilities with different efficiencies, and optimal waste and leachate flow allocation along with waste separation at the source for municipal solid waste (MSW) systems. The uncertainty in the generated amount of waste is also considered in different urban areas. Therefore, a two-stage stochastic programming has been developed to minimize the total cost and the leachate pollution potential of MSW network systems, considering leachate types, collection and garbage-bin-cleaning truck types, and recyclable waste quality. Furthermore, the social objective is to maximize the number of job opportunities. The sample average approximation approach and the augmented ε-constraint method have been implemented to address the model uncertainty and solve the proposed multi-objective model, respectively. The results have indicated that considering the leachate treatment in the MSW network and waste separation at the source, despite increasing the total cost, has decreased leachate pollution potential by 41.3% and has created the number of job opportunities by 29.2% compared to the current situation in Tehran as a case study. Moreover, complete waste separation at the source in the proposed model has shown that it can have a positive effect on decreasing the total cost and leachate pollution potential.