Effect of EDTA on Absorption of Imperata cylindrica L.and Scirpus triqueter L.on Heavy Metal in Soil
SHI Xiao-dong et al(College of Biological Resources and Environmental Science,Qujing Normal Univesity,Qujing,Yunnan 655011)
[Objective] The study aimed to explore the optimum method of combining biology and chymistry to artificially repair the soil polluted by heavy metal.[Method] In the pot test in greenhouse,with the Imperata cylindrica and Scirpus tripueter seeds selected in polluted area as tested materials,the effect of I.cylindrica and S.tripueter under regulation of EDTA with different concn.(1,3,5,10,15 mmol/L)on the accumulation of Cd,Zn,and Pb in soil.[Result] The regulation agent EDTA increased the absorption of I.cylindrica and S.tripueter on heavy metal in soil to different degree and enhanced the purification rate of plant on polluted soil.The purification of different polluted heavy metal element in soil by different plant needed regulation of EDTA with different concn.With the regulation of EDTA at 3 mmol/L,I.cylindrica had highest purification rate(0.226% and 0.305%,resp.)on the pollution of Cd,Zn in soiland with EDTA at 15 mmol/L,I.cylindrica had highest purification rate(0.047%)on the pollution of Pb in soil.With the regulation of EDTA at 10 mmol/L,S.triqueter had highest purification rate(0.305% and 0.042 % resp.)on the polution of Zn and Pb and with EDTA at 15 mmol/L,S.triqueter had highest purification rate(0.211%)on the pollution of Cd in soil.[Conclusion] The best method of restoring soil polluted by Cd,Zn and Pb was S.triqueter plus EDTA at 10 mmol/L.