Heavy Metal Contamination of Dumpyard Soils and its Phytoremediation with Vetiver Grass (Chrysopogon zizaniodes)

摘要

A study was conducted to find out the distribution of heavy metals and the pollution status of a majordumping site in Laloor, Thrissur, Kerala and also the effectiveness of vetiver in phytoremediation ofcontaminated soils. The total heavy metal content of the dumping sites was higher than the nondumping sites. The average content of total Pb was recorded as 82.84 mg kg -1 in the soils of Laloor.Monitoring the Co content of the soil, irrespective of different intervals and the sites of study, it wasfound that the average content was 7.79 mg kg -1 at Laloor. The average total Ni content registered atLaloor was 35.54 mg kg -1 . The Hg content of the soil was 0.42 mg kg -1 at Laloor. The average contentof Cr was found to be 115.67 mg kg -1 in Laloor soil. The result of heavy metal analysis was added tothe GIS layers created for the different sites of the location and the major pollution indices wererepresented in the map. The highest polluted site was identified in the Laloor dump site. The soil alongwith waste material collected from Laloor was used for phytoremediation study with vetiver grass.Phytoremediation with vetiver showed that it has good phytoremediation potential with a bioconcentration factor of more than two for metals like Ni, Cr and Hg. Vetiver is a good translocator of Crand most of the other heavy metals were stabilized in the root. On the basis of removal ratio, it removedheavy metals in the order Cr > Ni > Co > Pb.