A profit-oriented mathematical model for hazardous waste locating- routing problem

Hazardous waste management (HWM) deals with the safe, efficient and cost effective collection, transportation, treatment and disposal of wastes. This paper presents a profit- oriented mixed integer mathematical model for the hazardous waste location-routing problem, which incorporates the energy recovery from waste and the application of the polluter pays principle. The suggested model decides on the locations and numbers of recycling, incineration, sterilization, interim storage and disposal centers and on how to transfer various types of hazardous waste and waste residues among these centers from the perspective of environmental protection. The proposed model was implemented in a real life case study and tested on various hypothetical problem instances. In addition, an extended formulation was developed on a rolling horizon basis through the objective function of Net Present Value (NPV) to analyze the overall profitability of the entire HWM system for long-term planning and a sensitivity study was conducted on different interest rates. The results show that the model is applicable to real-life waste management systems and it can provide effective solutions for large-scale HWM problems.