BIOACCUMULATION OF SELECTED HEAVY METALS BY BACTERIAL STRAINS ISOLATED FROM WASTE WATER EFFLUENT OF PAKISTAN RE-ROLLING (STEEL MILL I-9, ISLAMABAD)

Abstract

In the present study, bacterial strains were isolated from wastewater samples of metal polluted environment. As a result, various 164 heterotrophic bacterial strains were isolated. Out of them only Bacillus sp. Is studied the multiple metal tolerance profile and bioaccumulation potentiality. We also analyze the metal contamination of selected area. The average abundance order heavy metal content in water sample was Zn>Pb. Zinc concentration was range from 39.832µg/L to 310.24 µg/L in water on the other hand lead concentration was 8.09µg/L to 25.23µg/L in water. Metal resistance studies of the bacterial isolates revealed that out of 164 isolates collected, bacillus sp. show tolerance to lead that was more than 6000µg/ml. Zinc tolerance was range around 500µg/ml. Bioaccumulation studies shows that with increase in time, biomass of selected strain also increase. Correspondingly, with increase in biomass, the heavy metal bioaccumulation of that selected bacterial strain also increase. In lead removal studies, around 10% of lead in experimental flask was absorbed by Bacillus sp. I zinc removal studies, about 13% of zinc was reduced in experimental flask. The obtained results showed that the selected Bacillus sp. is good bioaccumulation strain for lead and zinc ions.