Abstract:
Biosorption of Cr (VI) from aqueous as well as waste water was studied using indigenous bacteria, isolated from metal laden soil. Minimum inhibitory concentration (MIC) was carried out for three isolates of bacteria. The chromium (VI) contaminated wastewater was procured from one of the tannery and was analyzed for physiochemical parameters. The biosorption studies were carried out using live and dead biomass of selected bacterial isolates inoculated at different concentrations (50, 100 and 150 mg/l) of Cr (VI) at constant pH 4. The maximum biosorption, 110 mg/gm of biomass at the initial concentration of 150 mg/lit, among live bacterial isolates was observed in B2 isolated (lemon yellow coloured with drop like). The value of optimum dose was decided by the use of dead biomass and it was found 0.005gm at concentration of 150 mg/l. Biosorption was found increasing with the increase of time in live biomass and equilibrium state was reached in 72-96 hrs. The Freundlich isotherm model was applied and gave a good representation of the experimental equilibrium concentrations for biosorption of Cr (VI).
