The Influence of Vat Leach Reprocessed Tailings on Heavy Metals Levels around Sekenke Gold Mine, Iramba District, Tanzania

Abstract

Soil pollution is a worldwide phenomenon which results from both natural and anthropogenic activities. This has resulted in several health and physiological problems in both plants and human. This study investigated the concentration of heavy metal contaminants at Senkenke gold mining areas in nine tailings samples before processing and in nine tailing samples after processing using XRF Rigaku Nex CG and arsenic was determined using AAS equipped with a continuous flow of VGA. Arsenic mean concentration in unprocessed samples was 32.873 ± 26.284 mg/kg, while in processed tailings was 24.390 ± 19.394 mg/kg. The mean concentration of Pb in unprocessed tailing was 44.012 ± 37.091mg/kg, while in processed tailing was 38.402 ± 28.270 mg/kg. The mean concentration of Cd in unprocessed tailing was 4.513 ± 1.022 mg/kg, while in processed tailing was 3.089 ± 1.329 mg/kg. Chromium mean concentration in unprocessed tailing was 194.526± 22.670 mg/kg while in processed tailing was 141.352 ± 30.726 mg/kg. The Igeo values found in the following increasing order in unprocessed tailing Zn < Fe < Pb < Cr < As < Cd while in processed tailing was in the following increasing order Zn < Fe < Cr < As < Pb < Cd. The PLI values calculated for tailing samples are found to 4.423 for unprocessed tailing and 2.807 for processed tailing which shows that the soils are polluted and the environment is deteriorated in their quality. The findings revealed that the soils and mine tailings in the study area were polluted with heavy metals, particularly As, Pb and Cr and mostly Cd. The heavy metal concentrations decrease from unprocessed tailing to processed tailings. This pollution poses significant environmental and health risks.