STUDY ON PHYTOREMEDIATION OF HEAVY METALS IN THE SEDIMENTS OF HONGFENG LAKE BY FOUR SPECIES OF PASTURE GRASS

A pot experiment was conducted to study the accumulation and remediation efficiency of four different pasture grass ( Lolium perenne，Medicago sativa，Festuca arundinacea，Cichorium intybus) to heavy metals ( Zn，Cu，Pb，Cd) in the sediments of Hongfeng Lake． The results revealed that the heavy metals concentration decreased after planting the different pasture grass． The accumulation ability of Festuca arundinacea to Zn was relatively higher than the others，and Zn mainly accumulates within its shoots． For Cu and Pb，the accumulation abilities of Lolium perenne were relatively higher and mainly accumulate them within its roots． The differences in accumulation abilities of four plants to Cd were certainly small，and Cd mainly accumulate within the roots except Cichorium intybus ( within its shoots) ． Phytoremediation efficiencies of Lolium perenne on Cu、Pb and Cd were 38. 69%，17. 12%，31. 68%，respectively and higher than the others． Festuca arundinacea has higher remediation efficiency on Zn ( as high as 55. 03%) ． Furthermore，the translocation factor of Festuca arundinacea exceeded 1. 0，which suggested phytoextraction potentiality of Zn from the sediments．