Chemical and Biological Leaching Methods to Remove Heavy Metals from Sewage Sludge: A Review

Authors

  • Lugard N. Ukiwe Federal University of Technology, Owerri
  • Allinor J.I Federal University of Technology, Owerri
  • Ejele A.E Federal University of Technology, Owerri
  • Anyadiegwu C.I.C Federal University of Technology, Owerri
  • Ibeneme S.I Federal University of Technology, Owerri

DOI:

https://doi.org/10.24297/jac.v4i3.948

Keywords:

Acid, concentration, digestion, environment, extraction, organic, sludge.

Abstract

The removal of heavy metals (HMs) in sewage sludge (SS) is important since sludge is often disposed or applied on farmland to enhance soil fertility. The present study reviewed two conceptual approaches (chemical and biological leaching) of removing HMs present in SS. In the chemical leaching method, traditional acid treatment together with novel methods such as aeration, complexation and sequential extraction procedure have been reviewed extensively. Certain factors influence the removal of HMs in SS. These factors include; pH, leaching agent, redox potential, and contact time. Nitric acid (HNO3), hydrochloric acid (HCl), sulphuric acid (H2SO4), phosphoric acid (H3PO4), ethylenediamine tetraacetic acid (EDTA), as well as Thiobacillus thiooxidans and Thiobacillus ferrooxidans are the most widely studied leaching agents and substrates involved in the chemical and bioleaching processes. However, the bioleaching process has been proposed as a safe, efficient, economical, environmental friendly method to remove HMs in SS due to its simplicity, high yield of metal extraction, low acid consumption, and low sludge solids concentration. Nevertheless, the present review has noted that most researchers are of the opinion that more studies are needed in the bioleaching method in order to enhance its commercial attraction.  

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Author Biographies

Lugard N. Ukiwe, Federal University of Technology, Owerri

Department of Chemistry

Allinor J.I, Federal University of Technology, Owerri

Department of Chemistry

Ejele A.E, Federal University of Technology, Owerri

Department of Chemistry

Anyadiegwu C.I.C, Federal University of Technology, Owerri

Department of Petroleum Engineering

Ibeneme S.I, Federal University of Technology, Owerri

Department of Geosciences

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Published

2008-12-12

How to Cite

Ukiwe, L. N., J.I, A., A.E, E., C.I.C, A., & S.I, I. (2008). Chemical and Biological Leaching Methods to Remove Heavy Metals from Sewage Sludge: A Review. JOURNAL OF ADVANCES IN CHEMISTRY, 4(3), 509–517. https://doi.org/10.24297/jac.v4i3.948

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Articles