Optimizing Hierarchical Valorization Pathways in Plastic Waste Reverse Logistics with Contamination-Dependent Technology Selection

Plastic waste reverse logistics networks under Extended Producer Responsibility (EPR) face challenges such as variable source contamination and decisions on sorting center technologies. These factors affect system costs and recycling performance. Current models often address these issues alone, limiting understanding of EPR network design. This paper presents an integrated mixed-integer linear programming (MILP) model that coordinates technology selection at sorting centers, monitors contamination levels, manages recycler flexibility, and allocates waste flows across recycling, export, and landfill options. Applied to Québec's plastic waste management system, key findings include: 1) upgrading sorting centers is economically viable only above certain contamination levels; 2) sorting center upgrades become cost-justified above a 0.5 contamination multiplier, with total system cost rising from ~45M to ~65M CAD between the lowest and highest contamination scenarios ; and 3) recycler flexibility cannot compensate for poor sorting upstream, as quality issues dominate capacity constraints. These insights offer crucial thresholds for EPR infrastructure investment planning.