CSIRO PUBLISHING - Australian Journal of Chemistry

Microbial Reduction of Hexavalent Chromium in Landfill Leachate

Yarong Li ^A, Gary K.-C. Low ^A ^D, Ying Lei ^B, Cheryl E. Halim ^C and Rose Amal ^C

^A Environmental Forensic and Analytical Science Section, Department of Environment and Conservation (NSW), Lidcombe NSW 2141, Australia.
^B Institute for Biotechnology and Infectious Diseases, University of Technology, Sydney NSW 2065, Australia.
^C School of Chemical Engineering and Industrial Chemistry, University of New South Wales, Sydney NSW 2052, Australia.
^D Author to whom correspondence should be addressed (e-mail: lowg@epa.nsw.gov.au).

Abstract

Landfill leachates were found to exhibit reducing properties whereby chromium(vi) was converted into chromium(iii). The reduction is attributed to a microbial process in the presence of high concentrations of organic materials in the leachates. Nonputrescible landfill leachate (NPLL) was found to reduce Cr^VI to a lesser extent than the municipal landfill leachate (MLL). Microbial reduction of Cr^VI was also found to occur under alkaline conditions in extracts from a cementitious waste. A 55% reduction of Cr^VI was achieved by enriching the extract with bacteria and organic material.

Australian Journal of Chemistry 57(10) 967–970 doi:10.1071/CH04069
Submitted: 19 March 2004 Accepted: 25 June 2004 Published: 1 October 2004