Heavy metal source analysis in municipal solid waste (MSW): case study on Cu and Zn.

This research contributes to the knowledge of the heavy metal sources in municipal solid waste (MSW). Samples were collected from 8 cities of Zhejiang province, Eastern China. Cu and Zn, the most two conventional heavy metals with extensive distribution in many kinds of MSW components, were investigated. It shows components of kitchen waste (KW), ash (AS), plastic (PL), and paper (PA) have high universality in MSW and accounted for 55.1-95.5% in each MSW sample. Moreover, these four components are also the main heavy metal sources of MSW, which accounted for 76.3% and 82.3% contribution of the Cu and Zn contents, respectively. The Cu and Zn contents in the gross MSW sample were 41.2-1643.7 mg kg(-1) and 109.3-1077.9 mg kg(-1), respectively, which on different degree exceed the set standard for "environmental quality standard for soil" (Cu, 100 mg kg(-1); Zn, 400 mg kg(-1)) of China and have high potential of environmental risk. The heavy metal contents in the gross MSW do not have spatial variation but present high seasonal variation, significantly higher in summer than winter (P<0.01). Much more attention should be paid on the MSW management in summer to avoid heavy metal pollution.