CHEMICAL FRACTION ANALYSIS OF LEAD (Pb) IN SEDIMENT AT THE GOLD MINING AREA OF THAN SA COMMUNE, VO NHAI DISTRICT, THAI NGUYEN PROVINCE

Abstract

Mining operations have significantly impacted the environment, soil, water, and sediment within the vicinity of gold mining activities. The objective of this study is to analyze the chemical speciation of Pb in sediment samples from the Than Sa gold mining area to obtain comprehensive information regarding the level of Pb contamination in sediment samples from this area. Employing a sequential extraction procedure, the various forms of lead were extracted from six sediment samples. Using the ICP-MS method, the concentrations of lead and its chemical forms in the sediment samples were quantified. Results indicate that the mean total lead concentration in the sediment samples ranged from 29.16 ÷ 89.19 mg/kg, all of which were below the allowable threshold for lead according to Vietnamese regulations for freshwater sediments. The distribution of lead chemical forms in the soil samples predominantly follows the sequence F5 > F3 > F2 ~ F4 ~ F1. Assessment based on environmental risk evaluation parameters such as Igeo and RAC reveals that lead concentrations in the sediment samples pose low to moderate levels of risk of pollution.