The Potential of Bioaccumulation and Translocation of Heavy Metals in Plant Species Growing around the Tailing Dam in Tanzania

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Author(s) Nyatwere D. Mganga
Pages 690-697
Volume 3
Issue 10
Date October, 2014
Keywords Bioaccumulation factor; heavy metals; plant species; rhizosphere soil; translocation factor
Abstract

The present paper covers the probability of heavy metals bioaccumulation and translocation in twelve plant species growing around the tailing dam of North Mara gold mine. In the present study about 5 g of root and shoot portions of the randomly selected plant species that were growing around the tailing dam were separately collected. Besides, 10 g of soil samples were also collected from the rhizosphere at each sampling point where vegetations were previously sampled. The soils and vegetations were analyzed for four heavy metals (lead, zinc, cadmium and nickel) by Atomic Absorption Spectrophotometer. Bioaccumulation potential was measured in the plant species by calculating Bioaccumulation Factor (BAF). BAF was obtained from the ratio of metal content in plant roots to that of total metal content in the soil. Besides, translocation potential was determined by calculation of Translocation Factor (TF), which was obtained from the ratio of the metal content in the plant shoots to that in the plant roots. Of the studied plants, only Gomphrena celosioides L., Hibiscus nicranthus L., Indigofera cuneata Bak., Acacia albida Bentha. and Cynodon dactylon (L.) Pers. had BAF and TF > 1, suggesting their applicability in extraction of the studied heavy metal-polluted soils at the study area. Since heavy metal accumulation and subsequent translocation depends on climatic and edaphic factors, more local plants which are capable of accumulating heavy metals need to be identified and tested in situ.

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