ARUNDHATI PAL AND A. K. PAUL
Abstract
Biosorption of metal ions by microbial biomass has long been recognized as an effective tool in bioremediation of industrial wastewater. Dried mycelial biomass of 22 Streptomyces isolates were screened for biosorption of hexavalent chromium [Cr(VI)] from aqueous solutions. The isolates were capable of removing 23-64% of chromium from a solution of 100 mg Cr(VI)/L in 24h. Streptomyces DBCC-747, the most potent isolate absorbed Cr(VI) rapidly during the early phase (8-12h) of incubation but continued steadily till 32h. The optimum concentration of biomass and Cr(VI) for biosorption were 15g/L and 50mg/ L respectively. Sorption of Cr(VI) was maximum at pH 2.0 and was affected adversely at neutral to alkaline pH, but increased gradually with increasing dehydration of the mycelial biomass.