INVESTIGATION OF THE MECHANISM OF METAL UPTAKE BY DENATURED RHIZOPUS-ARRHIZUS BIOMASS

Chemical treatments to denatured Rhizopus arrhizus biomass were found to cause reductions in metal uptake capacities as high as 60%. Phosphate and carboxyl groups were identified as important moeities involved in metal binding. Scatchard analyses of uptake isotherms of native biomass confirm the existence of more than one type of binding site. An uptake model involving binding to a multiplicity of nonequivalent sites is proposed. The primary interactions are due to a complexation mechanism involving sites in the biomass containing carboxylate, phosphate, and other functional groups. Uptake may be enhanced by electrostatic attraction to negatively charged functional groups, but this is a secondary mechanism. © 1990.