Method for the recovery of Cr and Co species from effluents using agricultural adsorbent – immobilized E. coli, S. aureus and S. typhi isolates and FAAS detection

Abstract

Microbial chromium and cobalt reduction was investigated for application in their recovery from industrial wastewater using flame atomic absorption technique. This paper presents the development of a routine method for the recovery of Cr and Co species in microbial-treated industrial wastewater using agricultural adsorbents and silica gel. E. coli, S. typhi and S. aureus were used in reducing these heavy metals. Results indicate that the palm kernel shell charcoal exhibited a good recovery capacity in the presence of the bacterial strains. Recovery rates of Cr in the activated charcoal and a bacterial optimum growth at pH 7.2 – 7.4 and 37 °C are 99.72% (S. typhi), 99.61% (E. coli) and 99.64% (S. aureus), while that of silica gel are 98.08% (S. typhi), 98.79% (E. coli) and 98.02% (S. aureus). The recovery of Co using the palm kernel shell charcoal is 99.71% (S. typhi), 99.58% (E. coli) and 99.60% (S. aureus). The results using the silica gel are 98.36% (S. typhi), 98.82% (E. coli) and 99.42% (S. aureus). In comparison to silica gel the palm kernel shell exhibited a higher recovery rate of Cr and Co in the presence of the bacterial strains.

Keywords: Bacteria, adsorbent, heavy metal, wastewater, biosorption.