Optimization of batch process parameters for congo red color removal by neurospora crassa live fungal biomass with wheat bran dual adsorbent using response surface methodology

The present work deals with the application of response surface methodology (RSM) to study the effects of various operational parameters on the decolorization of Congo red (CR) from dye wastewater. The live fungal biomass of Neurospora crassa along with wheat bran was used as a dual adsorbent for the removal of CR color from aqueous solution. Decolorization experiments were conducted in batch mode by varying experimental factors such as initial pH, initial dye concentration, wheat bran dosage, live biomass dosage, wheat bran particle size, and agitation speed. The process parameters were optimized using central composite design (CCD) to attain the maximum percentage decolorization. Predicted values of percentage color removal were found to be in good agreement with experimental values, which indicates that the suitability of the model and the success of CCD in optimization of CR color removal process. Graphical response surface and contour plots were used to locate the optimum points. The regression model equation for percentage CR color removal was established. The optimum pH, dye concentration, wheat bran dosage, live biomass dosage, wheat bran particle size and agitation speed were found to be 6, 200 mg L^–1, 12.5 g L^–1, 2% (w/v), 150 µm, 150 rpm, respectively for CR color removal. Further, the batch experiments were conducted to study the effect of electrolytes, surfactants, mixture of dyes, and temperature on dye decolorization. We concluded that the live fungal biomass of Neurospora crassa with wheat bran was shown to be suitable dual adsorbent for adsorption of CR and it can be used effectively in wastewater treatment.