Optimization and statistical modelling of cadmium biosorption process in aqueous medium by Aspergillus niger using response surface methodology and principal component analysis

Biosorption is an efficient technology for the decontamination of metals from industrial wastewater. In present study, cadmium resistant fungal strain Aspergillus niger was isolated from the effluent of electroplating industry. The effect of five independent variables i.e. pH (2-8), initial Cd(II) ion concentration (20-180 mg/L), biomass dosage (0.5-2.5 g/mL), temperature (10-60 degrees C) and contact time (10-80 min) was studied on Cd(II) biosorption by employing Aspergillus niger using batch mode. Optimum conditions were selected for maximum biosorption. The experimental design i.e. Box- Behnken design (BBD) was aimed at distinguishing the optimum levels of the above selected process variables. Maximum biosorption was achieved at pH 5.0, initial Cd(II) concentration (100 mg/L), biomass dosage (1.5 g/mL), temperature (35 degrees C) and contact time (45 min). At optimum conditions, 93% removal of cadmium ions was achieved. The Principal component analysis (PCA) was performed to spot the correlation between the various parameters.