Optimization of simultaneous chemical and biological mineralization of perchloroethylene

Optimization of the simultaneous chemical and biological mineralization of perchloroethylene (PCE) by modified Fenton's reagent and Xanthobacter flavu s was investigated by using a central composite rotatable experimental desi gn. Concentrations of PCE, hydrogen peroxide; and ferrous iron and the micr obial cell number were set as variables. Percent mineralization of PCE to C O2 was investigated as a response. A second-order, quadratic response surfa ce model was generated and fit the data adequately, with a correlation coef ficient of 0.72. Analysis of the results showed that the PCE, concentration had no significant effect within the tested boundaries of the model, while the. other variables, hydrogen peroxide and iron concentrations and cell n umber, were significant at alpha = 0.05 for the mineralization of PCE. The C-14 radiotracer studies showed that the simultaneous chemical and biologic al reactions increased the extent of mineralization of PCE by more than 10% over stand-alone Fenton reactions.