Statistical optimization of process variables by response surface methodology to enhance phenol degradation by Pseudomonas putida (NCIM 2102)

Removal efficiency of phenol from aqueous solutions was determined using Pseudomonas putida (NCIM 2102). Experiments were made as a function of pH (4 - 9), temperature (28 - 36oC), and agitation speed (100 - 200 rpm). Optimization of these three process parameters for phenol degradation was studied. Statistically designed experiments using response surface methodology was used to get more information about the significant effects and the interactions between these three parameters. A 23 full-factorial central composite design was employed for experimental design and for analysis of the results. A second order polynomial regression model, has been developed using the experimental data. It was found that the degrading potential of P.putida (NCIM 2102) was strongly affected by the variations in pH, temperature and agitation speed. The experimental values were in good agreement with the predicted values and the correlation coefficient was found to be 0.9871. The optimum process conditions for maximizing phenol degradation were recognized as follows: pH (7.49), temperature (29.99oC), and agitation speed (138.89) rpm.