Reactive dye biosorption by Rhizopus arrhizus biomass

The biosorption of three commonly used reactive dyes, from aqueous solutions by oven-dried Rhizopus arrhizus biomass was studied in a batch system with respect to pH, initial dye concentration and initial metal ion concentration. The biomass exhibited maximum dye uptake at pH 2 due to its positively charged nature at acidic pH and the anionic nature of the reactive dyes. Reactive orange 16 dye was adsorbed most effectively to a maximum of approximately 200 mg/g. The presence of high levels of cadmium did not significantly impair the adsorption capacity of the biomass. Dye removal from a multicomponent solution of all three dyes was also achieved. Rhizopus biomass was found to exhibit superior removal properties than activated charcoal.