关键词: 可回收物, 组分, 理化特性, 生活垃圾, 广州

Abstract: Resource recycling and utilization is a key link in the construction of a “zero-waste city”, while the recycling and utilization of recyclable materials is a shortcoming in the work of waste classification. Taking typical areas as the entry point, through on-site investigation, experimental analysis and other methods, the generation and classification of recyclable materials in residents’ domestic waste were studied, and their components, physical and chemical properties were analyzed. The results indicated that the proportion of recyclable materials (9.9%-24.5%) in the components of domestic waste in Guangzhou’s sanitation collection system has gradually decreased over the past 10 years, with high-value recyclables averaging 6.73% and low-value recyclables exhibiting a decreasing trend. From 2021 to 2023, the proportion of high-value recyclables in domestic waste generated in G street (21.20%-33.34%) has been increasing year by year, while the proportion of low-value recyclables has decreased. According to the analysis of waste classification components in the black bins of G street, the proportion of recyclable materials has decreased from 23.73% to 15.80%, with paper, plastic, and metal all decreasing year by year. Regarding physical composition, the content of rubber and plastic (28.58%-31.28%) was relatively high, while the proportions of paper and glass were slightly higher.The physicochemical analysis of six waste categories showed that waste paper had the highest moisture content (38.94%±3.30%), while the high calorific value of plastic bags and plastics dry basis was higher than the average value of domestic waste. The ash content of plastic bags and paper scraps was relatively high, while the other four categories remained around 1.00%. The concentrations of Pb and Hg (on a dry basis) in plastic bags were the highest, measured at (11.75±6.18) mg/kg and (0.063±0.086) mg/kg, respectively. The total Cr and As contents of fabrics was the highest, and the mixture of plastic bags, fabrics and other materials into terminal incineration would increase the heavy metal toxicity of fly ash and slag. The results of this study can provide reference for selecting appropriate recycling methods for recyclable materials, while improving their recycling rate and economic value, and assisting in the construction of a “zero-waste city”.

Key words: recyclable materials, component, physical and chemical properties, domestic waste, Guangzhou