Optimization of variables for phenol degradation by the consortium was carried out using RSM. The variables like initial phenol concentration, temperature, pH and timewas optimized by using central composite design (CCD). The coded level of parameter is presented in Table 1. The significance of the regression coefficients was determined by Student’s t-test and the second-order model Eq. (3) was determined by Fisher’s test. The variance explained by the model is given by the multiple coefficient of determination, R2.