草本能源植物修复重金属污染土壤的潜力

在北京郊区重金属轻度污染土地开展了柳枝稷、荻、芦竹、杂交狼尾草四种草本能源植物的规模化种植,分析其对砷、汞、铜、铬、铅、镉等六种重金属的富集能力与修复潜力。结果表明,四种草本能源植物均属于非超积累植物,但柳枝稷、荻、芦竹、杂交狼尾草的生物质产量较高,分别为23.23t.hm-2、28.22t.hm-2、47.08t.hm-2、59.22t.hm-2,且不受重金属轻度污染的明显负面影响,因此其重金属绝对富集量可观。杂交狼尾草对砷、汞、铜、铅、镉的绝对富集量分别为23.12g.hm-2、0.35g.hm-2、1132.62g.hm-2、95.18g.hm-2、6.07g.hm-2,芦竹对铬的绝对富集量达到1333.37g.hm-2。草本能源植物对重金属污染土壤具有一定的修复潜力,并以杂交狼尾草最大,芦竹、荻、柳枝稷次之。

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.