In situ bioremediation of heavy metals in contaminated soil using microbial agents and planting experiments

Abstract

In this paper, two kinds of microbial agents – carbonate-microbe agents (CMA) and phosphate-microbe agents (PMA) – were used to remedy heavy metals in contaminated soil. Contrastive analysis of the remedying effects by CMA and PMA was obtained. Meanwhile, green vegetable cultivation and a vegetable transplanting experiment were conducted in contaminated soil that had been remedied by two kinds of microbial agents. The planting experiment clearly contributed to analysis of the remedying effect. The experimental results indicated that two kinds of microbial agents had a remarkable remedying effect on the heavy metals; the remedying effect of Cr2+ and Pb2+ by CMA was better compared with PMA, while the remedying effect of Cd2+ and Zn2+ by PMA was better than CMA, and the remedying effect of Cu2+ was almost equally good by two kinds of microbial agents. Bud rate and growth momentum improved significantly in contaminated soil after remediation, the concentration of heavy metals in seedlings and vegetables was reduced greatly, and several heavy metals indices were lower than the national standards. For different heavy metals pollution, different microbial agents should be used: namely the CMA are suitable for remedying Cr2+ and Pb2+, whereas PMA are suitable for remedying Cd2+ and Zn2+.