The objectives of this project were to establish the database of long-term physical and chemical characteristics of municipal solid waste (MSW) and to evaluate the variation of MSW composition and property by careful sampling, sample preparation and the analytical techniques. Meanwhile, the performance of this project could be also useful in adopting the strategies of MSW management, developing the innovative technologies of recycling and recovery, and assessing the safe technologies of MSW disposal.
According to the results of sampling and analysis, the major compositions of the MSW were paper, plastics, and food scraps. The composition content of the above waste was almost 88.83% of the total MSW. Paper products made up the largest component of MSW generated (37.60%, wet basis), and food scraps comprised the second-largest component (32.95%, wet basis). Plastics were also a major component in MSW. The average content of plastics was 18.28% (wet basis) of the total MSW in 2019. The contents of metals and glasses of the total MSW were 0.66% and 0.85%, respectively. Wood and yard trimming, rubber, leather, and textiles combined made up about 7.79% of MSW. The results showed that the variation of composition in food scraps was decreased in the past three years. To compare the moving average values (past three years) of food scraps composition, the food scraps content in MSW were decreased slightly from 36.68% to 32.95%. That is, the composition of food scraps of MSW decreased gradually in past three years. On the other hand, compositions of paper, plastics and metals of MSW sampled in 2019 were higher than that of moving average values (based on the past three years). Besides, the types of paper of MSW included office paper, newspaper, corrugated paper, paper bag, paper container, and paper for toilet products, etc. In this project, approximately 18% of paper for toilet products was found in MSW samples. The overall average moisture content in the MSW was found to be 49.68%. The combustibles made up an above 43.73% of the MSW on average due to the low content of metals, glass, and other inorganic components. The average lower heating value (LHV) was about 2080 kcal/kg. Based on observations of this project, it was concluded that a well-established database of MSW using the results of long-term sampling and analysis projects could reduce bias in results. This project also provided important information for consideration of strategies in MSW management.