Screening of selected plants for cadmium and lead phytoremediation

Abstract

Heavy metal contamination of soil has become a matter of serious concern that requires immediate attention. Phytoremediation is a recent strategy that makes use of plants to remove or stabilize contaminants present in the matrix in which they grow. The present study investigated cadmium and lead phytoremediation potential of the four plants namely Cosmos sulphureus Cav., Crotalaria pallida Aiton, Gaillardia aristata Pursh. and Gomphrena globosa L. It was found that with higher B.C.F. values (greater than one) for both cadmium and lead, G,aristata and G. globosa were good candidates for phytostabilising cadmium and lead. Since all the plants had T.F. values less than one, the potential risk of heavy metals entering the food chain is negligible. The study also tried to find out the effect of 100mg of cadmium and lead per kg of soil on the morphological features like root and shoot length and physiological features like fresh and dry weight of plants. It was found that 100mg of heavy metal (cadmium or lead) per kg of soil did not induce any visible toxicity symptoms like chlorosis, necrosis etc in the plants but caused a decrease in the root and shoot length, fresh and dry weight of plants.