Application of response surface analysis for biodegradation of azo reactive textile dye using Aspergillus foetidus

This paper reports the application of experimental design methodology for the optimization of decolourization of azo reactive textile dye Remazol Red RR and reduction of chemical oxygen demand (COD) using fungal isolate Aspergillus foetidus. Response surface methodology (RSM), involving central composite design matrix in three most important input variables; temperature, pH and initial dye concentration was employed. A total of 20 experiments were conducted in the study towards the construction of a quadratic model. This demonstrated the benefits of approach in achieving excellent predictions, while minimizing the number of experiments required. Very high regression coefficient between the variables and the responses indicated excellent evaluation of experimental data. Under optimized conditions fungal isolate was capable to decolourize Remazol Red RR up to 86.21% and COD reduction up to 55.43% was achieved during the experimental setup. Enzymatic activity indicated excellent outcome under the optimal process conditions. The experimental values agreed with the predicted ones, indicating suitability of the model and success of RSM approach in optimizing the process. ((c) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)