CADMIUM BIOSORPTION BY STREPTOMYCES-PIMPRINA WASTE BIOMASS

Biosorption of cadmium from solution was studied using a hamycin-producing Streptomyces pimprina waste biomass. Mycelial pretreatments with 80% ethanol increased the uptake of cadmium threefold. The rate of uptake of the metal was maximum in the first 10 min and the equilibration of the system was achieved after 60 min. At pH 2.0 there was no adsorption of cadmium; however, as the pH of the solution increased, a rise in the adsorption could be noticed, which peaked at pH 5.0. The uptake of cadmium was found to increase linearly as a function of cadmium concentration up to 500 mg/l. The data could be fitted to Freundlich and Langmuir models for adsorption processes. A 0.1 M EDTA solution could desorb cadmium loaded on S. pimprina biomass with the highest efficiency.