YIN Xin，ZHOU Guangzhu，WANG Cuizhen，WANG Shihao，CHENG Weiyu

( College of Chemical and Environmental Engineering，SDUST，Qingdao 266590，China)

Abstract：Heavy metals including As, Pb, Cu, Zn, Cd and Cr in Lead and Zinc slag from Zhehai Area, China were determined and their ecological risk was discussed in this paper. The chemical fraction of the heavy metals were investigated with BCR sequential extraction procedure, and ecological risk of heavy metals was assessed based on the single factor pollution index, the potential ecological risk index and the risk assessment coding method. Results show that,(1)according to grade Ⅲ of China environmental quality standard for soil (GB15618-1995), contents of heavy metals (Cd, Zn and Cuin neutral dregs, Cd, Zn and As in water-quenched slag) are higher than the limit of the standard. Cd, Zn and Cu in neutral dregs and Cd, Zn in water-quenched slag have high pollution levels, and As in water-quenched slag has a little pollution level;(2)according to neutral dregs, Pb, Zn, and Cr are mainly in the reducible fractions, Cd and Cu are mainly in the acid soluble fraction, and As exists mainly in residual fractions. And for water-quenched slag, residual fraction is the dominant form of Pb, Cd, Cr and As. Cu and Zn are mainly in oxidizable and reducible fractions; (3) based on calculation of potential ecological risk index and risk assessment, Cd and Zn in neutral dregs show considerable and high ecological risk, while Cd in water-quenched slag has a little higher ecological risk comparing with other heavy metals. The potential ecological risk values are in the range of 183.81-5357.58, and they are at the medium to high ecological risk levels. Cd is the main ecological risk contributor; and(4)RAC assessment results show that Cd and Cu are of very high and high risk while Cr and As are of medium risk in neutral dregs. Cd, Zn and As in water-quenched slag represent medium risk comparing with other heavy metals of low risk. The order of RAC index of different heavy metals in neutral dregs is Cd＞Cu＞Cr＞As＞Zn＞Pb and in water-quenched slag is Zn＞As＞Cd＞Cr＞Cu＞Pb.

Key words：Lead slag; zinc slag; heavy metal; speciation; risk assessment

EARTH AND ENVIRONMENT Vol.44, No.4 Tot No.312, 2016, Page 478