Biosorption of heavy metals by four acclimated microbial species, bacillus spp., pseudomonas spp., staphylococcus spp. and aspergillus niger

Abstract

The four acclimated microorganisms viz. Bacillus spp. Pseudomonas spp., Staphylococcus spp., and Aspergillus niger, were isolated from soil and sludge undergone enrichment process. They were allowed to grow in synthetic media amended with heavy metal solution. The waste samples both solid and liquid were collected and chemical parameters was checked viz. pH, BOD, COD, chloride, fluoride, TDS and TH. The heavy metals Mn, Cd, Cr, Cu, Zn and Pb were determined in liquid waste and industrial wastewater, while other metals viz. Cr, Co, Zn, Mn and Ni were measured in leachate (solid waste). The acclimated microorganisms were used to remediate the waste by biosorption process in a Batch culture. Pseudomonas sp. and Bacillus sp. reduced Cu 4.165mgl-1 and 3.332 mgl-1(68% and 56%) and Ni 5.015 mgl-1 and 3.8 mgl-1 (65% and 48%) respectively. Aspergillus niger reduced Cd 0.267 mgl-1 (50%) and Zn 5.988 mgl-1(58%) whereas Staphylococcus sp. reduced Cr 4.108 mgl-1(45%), Cu 2.615 mgl-1(42%) and Pb 0.813 mgl-1 (93%). The results showed that Pseudomonas sp. reduced heavy metals more than other microbes but Staphylococcus sp. reduced lead 93% which was surprising and very much amount of lead uptake by Staphylococcus sp.