An inexact two-stage multi-objective waste management planning model under considerations of subsidies and uncertainties: A case study of Baotou, China

Government subsidy for waste incineration is an effective measure to promote the economic growth of the waste management system. It is of vital importance to formulate optimal management strategies for decision-makers by considering conflicting objectives among system cost and environmental risk under complex uncertainties. In this study, an inexact two-stage multi-objective planning (ITMOP) model is proposed for supporting municipal solid waste (MSW) management. This model advanced existing optimization methods through integrating interval linear programming and two-stage stochastic programming within the multi-objective programming framework, where various uncertainties expressed as interval value and probability distributions were effectively reflected. The environmental risks associated with exhaust gas and leachate emission from incineration and landfill are quantitively assessed. The economic performance of these two waste disposal facilities is evaluated through the introduction of different energy recovery and subsidy policy scenarios. The ITMOP-based municipal solid waste management model is applied to a case study of MSW management planning in the Baotou city of China. Ten scenarios integrated with different economic incentives are designed for analyzing the optimized solutions. The generated waste flow allocation pattern and facility expansion capacity results provide scientific waste management strategies for local authorities. Moreover, the obtained total system cost and environmental risks under different scenarios can help policymakers resolve eco-economic conflicts according to their preferences. Waste incineration will gradually replace landfilling as the mainstream of waste treatment in the future. Revenues from energy recovery and financial subsidies for incineration can compensate for its high economic cost and promote waste resource utilization. The results indicate that the local government can use the subsidy policy to encourage waste disposal to proper facilities and simultaneously reduce environmental emissions.