CHEMICAL SPECIATION ANALYSIS AND ASSESSMENT OF POLLUTION RISK BY Pb IN TAILING SOIL OF THE Pb/Zn MINING ORE ZONE IN HICH VILLAGE, DONG HY DISTRICT, THAI NGUYEN PROVINCE

Abstract

The metal speciation analysis in the soil is essential to assess contamination and environmental risk pollution of lead in the mining areas. This study applied Tessier’s sequential extraction procedure to investigate lead (Pb) speciation in tailing soil samples in the Hich village lead/zinc mining area in Dong Hy district, Thai Nguyen province. The results showed that Pb existed mainly in carbonate (F2) phases and minimally in the organic bonds (F4). Besides, it also presented in the fractions of Fe-Mn oxi-hydroxide (F3), exchange (F1), and residue (F5). According to the risk assessment index (RAC) and the national technical regulation on soil quality (QCVN 03-MT:2015/BTNMT), the pollution levels of Pb in tailing soil samples in the lead/zinc mining area were at a high level and very high risk of pollution.