Changes in the environmental impacts of the waste management system after implementing the waste-sorting policy: A Beijing case study

Quantifying the environmental impacts of a household waste-sorting policy on the household waste management system, including collection, transportation, and treatment, is the basis for evaluating the policy's effectiveness. Beijing, the capital of China, began to implement the mandatory domestic waste-sorting policy in May 2020. In this study, we aimed to evaluate the environmental impacts of the household waste management system in Beijing before and after implementing the sorting policy using the life cycle assessment method. Implementing the policy at the waste collection stage reduced the environmental impacts by minimizing the number of garbage bins consumed through their removal and consolidation. At the transportation stage, implementing the policy increased the environmental impacts per unit of waste via transportation structure changes. However, the overall impact was reduced because more recyclable materials were separated after waste sorting. The environmental impacts were reduced after implementing the policy at the treatment stage mainly because of the change in waste composition and the decrease in the total volume of treatment. Global warming potential (GWP) was the main contributor to the environmental impacts. After waste sorting, the GWP of the collection, transportation, and treatment stages decreased by −19.96%, −24.36%, and −38.08%, respectively, resulting in a total GWP reduction of −37.90%. However, incineration and biochemical treatments may offer environmental benefits.