Removal of CI Acid Blue 29 from an aqueous solution by Aspergillus niger

Removal of C.I. Acid Blue 29 from an aqueous solution by biosorption on dead Aspergillus niger fungus was investigated. Pretreatment with sulfuric acid was most effective with a biosorption capacity of 13.82 mg/g biomass compared with 6.63 mg/g of living biomass. Batch pH, kinetic, and isotherm studies were conducted to evaluate the biosorption capacity of the most effective pretreated biomass. The pH of the dye solution strongly affected the biosorption capacity. The effective pH was 4 and the corresponding biosorption capacity was 18.15 mg/g biomass. The kinetic studies showed that equilibrium was reached in 24 hours, and Lagergren first-order and Ho, et al. pseudo second-order rate equations were able to provide a realistic description of biosorption kinetics. Isotherm studies indicated that biosorption followed the Langmuir, Freundlich, and BET isotherms models.