Potentiality of herbaceous bioenergy plants in remediation of soil contaminated by heavy metals.

Accumulative ability and remediation potentiality of four herbaceous bioenergy plants,switchgrass,silverreed,giantreed and hybrid pennisetum,to six heavy metals,As,Hg,Cu,Cr,Pb and Cd,were systemically examined through the large-scale cultivation in one area contaminated slightly by heavy metals in Beijing suburb in order to analyze their accumulation characteristic to heavy metals.The results showed that these four herbaceous bioenergy plants were all non-hyperaccumulators.But because all of them had relatively high biomass yields,23.23 t·hm-2,28.22t·hm-2,47.08t·hm-2,59.22t·hm-2,respectively,and were not affected significantly by the slight contamination of heavy metals in soil,the accumulation of heavy metals in these four plants was relatively high.The absolute accumulation quantity of As,Hg,Cu,Pb,Cd in hybrid pennisetum was 23.12g·hm-2,0.35g·hm-2,1132.62g·hm-2,95.18g·hm-2,6.07g·hm-2,respectively,Cd in giantreed,1333.37g·hm-2.The data mentioned above indicated that herbaceous bioenergy plants had some potentiality in the remediation of soil contaminated by heavy metals,and hybrid pennisetum was optimal,followed by giantreed,silverreed and switchgrass.