The optimization of the photooxidative process was carried out with the application of Response Surface Methodology (RSM) to degrade Reactive Red 223 (RR223) dye. Operational parameters of U.V/H2O2 process such as irradiation time, initial [dye], initial [H2O2] and distance between U.V lamp and the solution were optimized with Central Composite Design (CCD). Correlation coefficient value of the CCD was obtained to be 79 %, showing the correctness of the model and the successful utilization of CCD in getting desired levels of the factors of the process. Moreover, the optimum points were located with the graphical surface and contour plots. At the optimal conditions, the photooxidative removal of the color and COD were observed to be 68%, 81%, respectively. Furthermore, the pseudo-second order kinetic was guiding the removal of the dye in the process. Subsequently, the electrical energy consumption was estimated in term of the merit electrical energy per order (EEO). The figure of merit of the process was found to be 252 kWhm−3 order−1. The cost of the treatment was also calculated to be US$ 25/m3.

Abdul Rauf Shah, Hajira Tahir and Tahira Yasmeen