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Biological leaching of heavy metals from a contaminated soil by Aspergillus niger
- Source :
-
Journal of Hazardous Materials . Aug2009, Vol. 167 Issue 1-3, p164-169. 6p. - Publication Year :
- 2009
-
Abstract
- Bioleaching of heavy metals from a contaminated soil in an industrial area using metabolites, mainly weak organic acids, produced by a fungus Aspergillus niger was investigated. Batch experiments were performed to compare the leaching efficiencies of one-step and two-step processes and to determine the transformation of heavy metal chemical forms during the bioleaching process. After the one or two-step processes, the metal removals were compared using analysis of variance (ANOVA) and least-significance difference (LSD). A. niger exhibits a good potential in generating a variety of organic acids effective for metal solubilisation. Results showed that after the one-step process, maximum removals of 56%, 100%, 30% and 19% were achieved for copper, cadmium, lead and zinc, respectively. After the two-step process, highest removals of 97.5% Cu, 88.2% Cd, 26% Pb, and 14.5% Zn were obtained. Results of sequential extraction showed that organic acids produced by A. niger were effective in removing the exchangeable, carbonate, and Fe/Mn oxide fractions of Cu, Cd, Pb and Zn; and after both processes the metals remaining in the soil were mainly bound in stable fractions. Such a treatment procedure indicated that leaching of heavy metals from contaminated soil using A. niger has the potential for use in remediation of contaminated soils. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 03043894
- Volume :
- 167
- Issue :
- 1-3
- Database :
- Academic Search Index
- Journal :
- Journal of Hazardous Materials
- Publication Type :
- Academic Journal
- Accession number :
- 40117093
- Full Text :
- https://doi.org/10.1016/j.jhazmat.2008.12.104