Abstract:

 The recycling and utilization of renewable resources is a key link in the construction of a "waste free city", and the recycling and utilization of recyclable materials is a shortcoming in MSW. This study focuses on typical regions, investigating the generation and classification of recyclables in household waste through literature review, field surveys, and experimental analysis, with an emphasis on their composition and physicochemical properties. The results indicate that, over the past 10 years, the proportion of recyclables (9.9% to 24.5%) in the components of household waste in Guangzhou's sanitation collection system has gradually decreased, with high-value recyclables averaging 6.73% and low-value recyclables exhibiting a decreasing trend. From 2021 to 2023, the proportion of high-value domestic waste generated in G Street (21.2%-33.34%) has been increasing year by year, while the proportion of low value waste has decreased.. According to the analysis of garbage classification components in the black bins of G Street, the proportion of recyclable materials has decreased from 23.73% to 15.8%, with paper, plastic, and metal all decreasing year by year. Regarding physical composition, the content of rubber and plastic (28.58% to 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 plastic bags and plastics is higher than the average value of household 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) and (0.063±0.086) mg/kg, respectively, followed by elevated levels of total Cr and As. The total Cr content of fabrics is the highest, and the mixing of plastics, fabrics, etc. into terminal incineration will 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, improving their recycling rate and economic value, and assisting in the construction of a "waste free city". 

Key words:  recyclables; component; physical and chemical properties; domestic garbage')">

 recyclables; component; physical and chemical properties; domestic garbage, Guangzhou