Bioaccumulation of Selected Heavy Metals in some Plants Growing Around Artisanal Gold Mining Sites in Kataeregi, Niger State, Nigeria

Abstract

This investigation was carried out to assess bioaccumulation of selected heavy metals in some plants growing around artisanal gold mining sites in Kataeregi, Niger state, Nigeria and to ascertain the selection criterion for candidate plant’s capacity for phytoremediation in the process of cleaning up the metal-contaminated soil of the site. At mining sites, samples of soil and eight distinct plant species were gathered. An atomic absorption spectrometer was employed to ascertain the concentration of bioaccumulation of selected heavy metals in the soil and different parts of the plants. Pb content of the soil was 1071±168.8 mg/kg while Cd, Cr, Zn, and As were 13.38±0.432, 10.26 ±1.635, 194.6±6.245 and As 11.08±2.06 respectively. While the result of hyper bioaccumulation ability of the collected plants shows that Calotropis procera recorded highest root and stem Pb contents of 87±31.0 and 87.3±1.20mg/kg respectively. For Cd, Azadiracta indica, E camaldulensis recorded highest root cadmium content of 1.7±0.28 and 8±0.54 respectively. Azadiracta indica recorded the highest Cr in root, stem and shoot measuring 21±6.27, 18±0.38 and 16±0.38mg/kg respectively. Eucalyptus camaldulensis and Vitallaria pardoxa recorded the highest root, shoot and leaves Zn content of 142±4.8, 107±0.89, 98±0.30,56±0.30, 93±0.86 and 153±0.68 mg/kg respectively. For As, the highest concentration was recorded in root of Ocimum basilicum with 11.89±0.01 mg/kg while the stem of Calotropis procera recorded highest of 2.70 mg/kg. The three plants examined had bioaccumulation potential and can be used for phytoremediation.