Objective: To investigate the removal of cadmium from aqueous solution by waste fungal biomass of Aspergillus niger, originated from citric acid fermentation industry.
Methods: Batch adsorption test was used to study the biosorption equilibrium and isotherm. The Cd2+ concentration was measured with atomic adsorption spectrophotometer (AAS) HITACHI 180-80.
Results: The biosorption achieved equilibrium within 30 min. The adsorption isotherm could be described by Freundlich adsorption model, and the constants K(F) and 1/n were determined to be 2.07 and 0.18, respectively, and the correlation efficiency was 0.97. The optimal pH for Cd adsorption was 6.0. The cadmium-laden biomass could be effectively regenerated using 0.1 N HCl.
Conclusion: The waste biomass of Aspergillus niger, a by-product of fermentation industry, is a potential biosorbent for the removal of cadmium from aqueous solution.