Author(s): WANG Xinxin, ZHANG Ying, WANG Yuanfen
Pages: 2207-2211
Year: 2008 Issue:  6
Journal: Ecology and Environment
Keyword:  nanoscale iron; remediation; hexavalent chromium; sediments; soil enzymes;
Abstract: A series of laboratory experiments were performed to elucidate the removal of hexavalent chromium in the sediments using nanoscale iron. The activities of polyphenol oxidase, calatase, protease and urease were measured to assess the restoration of soil enzymes after the remediation. The results showed that nanoscale iron had excellent ability to remove hexavalent chromium from contaminated sediments. After 16 days remediation using nanoscale iron, the removal rate of hexavalent chromium were all higher than 99.7% at different concentration of hexavalent chromium from 30～100 mg·kg-1. Hexavalent chromium was found to inhibit the activities of polyphenol oxidase, calatase, protease and urease significantly. There was a significant negative correlation between polyphenol oxidase and hexavalent chromium concentration, so it was presumed to use polyphenol oxidase activity as primary biochemical index to evaluate hexavalent chromium pollution. The activity of urease was restored to the control level after 16 days remediation using nanoscale iron, while the remediation had no obvious effect on the activity of calatase. Yet it was depressed that the activity of polyphenol oxidase and protease were not restored to the control level in the course of experiments, so the further research was still needed.