Review on Remediating Farmland Soil Contaminated by Heavy Metals with Cash Crops

Heavy metal pollution in agricultural soils in China is serious,and there is much spatial variation in metal pollution.Phytoremediation of the contaminated soils is a newly developed,eco-friendly and low-cost green technology,and it makes up for some shortages of traditional remediation technologies such as chemical leaching and chemical immobilization.Phytoremediation of moderately and heavily polluted soils with cash crops not only maintains value of soil but also increases farmers' income.Furthermore,the technology is easily popularized and harvested products without entering the food chain.The authors reviews remediation efficiency of common energy plants and fiber crops on contaminated soils and discusses various utilization ways of plant residues.For instance,plant residues can be used as raw materials of some green energy such as biomass fuel,ethanol and biogas,and meanwhile it effectively reduce usage of primary energy such as coal and oil and subsequently reduce emissions of dust,sulfur dioxide and nitrogen oxide. Overall,phytoremediation can bring significant social,economic and environmental benefits.