The effect of source separation on the waste disposal process: Case study in Hangzhou

Abstract

MSW source separation is a key procedure for its later processing. Kitchen waste, the main contributor to moisture content, accounts for a very high proportion (~60%) in MSW composition. The feasible way to dispose of MSW before or after separation depends on the reasonable disposal of kitchen waste. Here, a case study from Hangzhou, China, is presented in terms of the source separation effect on the waste disposal process. In Hangzhou, three strategies, including direct digestion without separation, composting after separation, and co-digestion with fruit and vegetable waste, were explored. It indicates that: 1.MSW digestion without separation is a possible means of refuse disposal. The refuse and leachate in the reactor connected with the aged refuse column and reached a strongly degraded and more stable state compared with directly recycled leachate.2.Kitchen waste composting after source separation is a better choice. However, the high water content is the key issue that needs attention. Especially, the water state should be paid more attention to. Additives like PAM can significantly enhance the capillary force and delay the decrease in moisture content during aerobic decomposition and improve the composting process.3.Kitchen waste co-digestion with fruit and vegetable waste has a high application potential. The two-phase AD with 50% kitchen waste was a reasonable ratio in this two-phase AD system.