Spatial and Temporal Evaluation of the Heavy Metal Lead in the Soil and Ground Water of Abandoned Gold Mining Sites Using ICP-0ES and AES-A Critical Study

Abstract

INTRODUCTION- Kolar Gold Fields, a town in the state of Karnataka, India, had the second deepest mine in the world when it was fully functional. The mining company at KGF has produced 40 tonnes of tailings, comprising of various heavy metals, which causes detrimental effects on biotic and abiotic components.

Method-The study has a bifold objectives, firstly to determine the concentration of lead (Pb) in the soil and ground water within the vicinity of a historical gold mine region located in the Kolar Gold fields (KGF), Karnataka. The study employed Thermo Scientific’s Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) and ICP-AES using Iteva software. Four soil and ground water samples were collected from the selected study sites (A, B, C and D) and examined between January - December 2023.

RESULTS- The highest level of lead that can be present in the soil is 98 mg/kg (WHO 2008). The highest average lead content in the soil samples during January-December 2023 analyzed from Champion was 120.83 mg/kg, followed by site A, D, and B respectively. The maximum permissible limit of lead in groundwater is 0.05 mg/L (USEPA 2009). The ground water analysis revealed that the ground water was highly contaminated with lead (0.863 mg/L) in site C (Champion). The average lead content is found to be 0.559 mg/L, at sites B, A and D is 0.323 mg/L, B, 0.277 mg/L 0.161 mg/L respectively. The pH and electrical conductivity of all the water samples were within the permissible limits, but hardness of the ground water was two times higher than the permissible limit in the sample site D (Balghat).

CONCLUSIONS-Site C had the highest lead content in both soil and ground water, almost 1.2 times higher in soil and in ground water it was 17 times higher than permissible limits.