Effect of pre‐treatments on biosorption of Ni (II) by dead biomass of Mucor hiemalis

Abstract

AbstractThe removal of Ni (II) from aqueous solutions by the physico‐chemically treated fungal biomass of Mucor hiemalis was investigated in the batch mode. Treatment of the autoclaved biosorbent with alkali chemicals, detergents, salts, cross linker, organic acid, organic solvent and oxidizing agent showed varying effects on the uptake capacity of Ni (II) and loss in biomass. Pre‐treating the autoclaved biomass with 0.5 M Na2CO3 for 24 h yielded biosorption capacity of 13.60 mg/g biomass at pH 8.0. The possible binding sites on the biosorbent involved in Ni (II) complexation were evaluated by chemical and instrumental analysis including potentiometric titration, infrared spectroscopy and scanning electron microscopy. The amine, amide and carboxyl groups were recognized as important in the biosorption of Ni (II) by M. hiemalis biomass. Chemical modification of the biomass by methylation of the amine groups and esterification of the carboxyl groups significantly decreased the biosorption of Ni (II) thus confirming their role in biosorption.