Characteristics and mechanism analysis of modified Streptomyces erythreus adsorbing Pb2+

Using Streptomyces erythreus isolated from pharmaceutical residues as biosorbent, the characteristics and mechanism of its absorbing Pb²⁺ was studied. The results showed that absorptive ability of bacterial mycelia modified by sodium hydroxide was improved greatly. The optimum conditions should be 0.2 g dosage of bacterial mycelia, time 10 min, pH value 3.5 and room temperature under initial Pb²⁺ of 11.8 mg/L when its absorptive capacity decreased fastest. The reaction mechanism of modified bacterial mycelia uptake Pb²⁺ was analyzed by back scattered electron (BSE) and infrared spectroscopy (IR). The results of experiments indicated that some chemical groups such as -COO-,C-H and O-H among cell walls of bacterial mycelia might play the key functions adsorbing Pb²⁺. It was presumed that the process of modified bacterial mycelia lead uptake might be a chemical and physical process collaboratively which occurred on the cell surface of bacterial mycelia chiefly based on exchangeable reaction.