Batch Studies on Biosorption of Chromium from Waste Water using Bacterial Cultures

Biosorption can be an effective technique for the treatment of heavy metal bearing waste water resulting from humuns and industrial activities. Several gram positive and gram negative bacteria have the ability to remove the heavy metals and there by making water contaminant free. It has been reported that attenuated bacterial biomass have greater biosorption capability than viable cells. In the present study, the biosorption of heavy metals using individual and mixed culture of attenuated bacteria (gram positive and gram negative) like Bacillus subtilis and Pseudomonas aeruginosa and parameters affecting the biosorption of heavy metals; such as time, pH, biomass concentration and initial metal concentration have been investigated. The batch experiments have been carried out using individual and mixed bacterial culture and the biosorption parameters were optimized using univariate procedures. The biosorption of Chromium (VI) showed that 77.6% for mixed cultures, 60.5 and 81.3 for Pseudomonas aeruginosa and Bacillus subtilis respectively. The optimum biomass concentration was found to be 1.5, 1.5 and 2 for mixed cultures (Pseudomonas aeruginosa and Bacillus subtilis) at 32C and 3 pH. Maximum sorption was achieved with Bacillus subtilis compared to Pseudomonas and mixed cultures. Keywords— Biosorption; Bacillus subtilis; Pseudomonas aeruginosa;heavy metals;wastewater.