Comparison of Myagrum perfoliatum and Sophora alopecuroides in phytoremediation of Cd- and Pb-contaminated soils: A chemical and biological investigation.

Phytoremediation is one of the most cost-effective and environmentally friendly ways to reduce adverse effects of cadmium (Cd) and lead (Pb) in the environment. The present study was conducted to investigate the bioaccumulation factor (BF) and translocation factor (TF) of Cd and Pb in muskweed (Myagrum perfoliatum) and foxtail sophora (Sophora alopecuroides). The impact of contamination on some growth responses of plants and soil biological indicators was also evaluated. A non-contaminated soil sample was divided into several subsamples: one subsample was left as control (without contamination) and the others were separately contaminated with three levels of Cd (3, 5, and 10 mg kg-1) and Pb (100, 300, and 600 mg kg-1). Pot experiments were performed under greenhouse conditions. The BF values of Cd were greater than 1 at all contamination levels indicating the potential of muskweed and foxtail sophora for the uptake and phytostabilization of Cd. The only TF > 1 was obtained for Cd in muskweed grown at the highest Cd contamination level. The TF values of Pb were much lower than those obtained for Cd indicating that Cd was more translocated from root to aerial parts of muskweed and foxtail sophora compared to Pb. The highest contamination levels of Cd and Pb did not significantly affect growth responses of muskweed and foxtail sophora. Furthermore, the cultivation of muskweed and foxtail sophora reduced the impact of Cd and Pb contamination on biological indicators including carbon mineralization ratio (CMR), substrate-induced respiration (SIR), microbial biomass carbon (MBC), and metabolic quotient (qCO2).