ANALYZING CHEMICAL FRACTIONATION OF SILVER (Ag) AND ASSESSING THE POLLUTION RISK LEVEL IN SOILS IN A Pb/Zn MINING ZONE , IN THAI NGUYEN PROVINCE

Abstract

Soil and the environment in the Pb/Zn mining area, in Hich Village have been seriously affected by mining activities. Chemical fractionation analysis of silver is necessary to obtain comprehensive information on the silver contaminated level in the soil of the present area. Sequential extraction procedure was utilized to determine the chemical fractionations of silver in the soil. The silver content in the soil and chemical fractions was analyzed using the ICP-MS. The results showed that the mean contents of silver in the tailing sample and field soil were 61.22 ± 7.15 mg/kg and 0.80 ± 0.25 mg/kg, respectively. Silver’s chemical fractionations in tailing soil were in the order of F5 > F3 > F1~ F2 > F4, while that of field soil were F3 > F5 > F1~ F2 > F4. According to the environmental assessment index, ICF, and RAC, silver’s content in the field soil was in the level of low or medium risk, while that was in the level of no risk or low risk with tailing soil.