Biosorption of chromium and nickel by heavy metal resistant fungal and bacterial isolates

Shankar Congeevaram, Sridevi Dhanarani, Joonhong Park, Michael Dexilin, Kaliannan Thamaraiselvi

Research output: Contribution to journalArticlepeer-review

356 Citations (Scopus)

Abstract

Microorganisms play a significant role in bioremediation of heavy metal contaminated soil and wastewater. In this study, heavy metal resistant fungi and bacteria were isolated from the soil samples of an electroplating industry, and the bioaccumulations of Cr(VI) and Ni(II) by these isolates were characterized to evaluate their applicability for heavy metal removal from industrial wastewaters. The optimum pH and temperature conditions for both the growth and heavy metal removal were determined for each isolate. The optimal pH for fungal isolates was lower (5-5.2) than that for bacterial isolates (7). The observed effect(s) of pH was attributable mainly to organism-specific physiology because in all the tested cases the cellular growth positively correlated with heavy metal removal. Batch and tolerance experiments provided information for solid retention time (SRT) design and the lethal tolerance limits for the isolated microorganisms. Experimental results indicated that expanded SRTs (stationary phase) can be recommended while using the fungal and bacterial Cr-resistant isolates for removing chromium. In the case of Ni-resistant bacterial isolate, a non-expanded SRT was recommended for designing continuous-flow completely stirred (CFCS) bioreactor so that a mid-log phase of cellular growth can be kept during the bioaccumulation process. The tolerance data with a high range of heavy metal concentrations revealed the Cr-resistant isolates, especially the fungal one, could tolerate chromium toxicity at up to 10,000 mg L-1 chromium. Result indicates the applicability of the isolated Micrococcus sp. and Aspergillus sp. for the removal of chromium and nickel from industrial wastewater.

Original languageEnglish
Pages (from-to)270-277
Number of pages8
JournalJournal of Hazardous Materials
Volume146
Issue number1-2
DOIs
Publication statusPublished - 2007 Jul 19

All Science Journal Classification (ASJC) codes

  • Environmental Engineering
  • Environmental Chemistry
  • Waste Management and Disposal
  • Pollution
  • Health, Toxicology and Mutagenesis

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