Comparison of the Performance of AOP Method Using O3/H2O2 in the Presence of TiO2 and ZrO2 Nano Particles Stabilized on Pumice for the Removal of Pentachlorophenol from Aquatic Solution: Kinetic Studies

Pentachlorophenol is one of the resistant phenol compounds has classified in the group of the primary pollutants due to its high toxicity and carcinogenic potential. The aim of this study is determining the efficiency of advanced oxidation process method using O3/H2O2 in the presence of TiO2 and ZrO2 nano-particles stabilized on pumice for the removal of PCP from aquatic solutions. This experimental study was performed in a batch reactor at laboratory scale. In this study, the effects of reaction time, initial concentration of PCP, pH, concentration of catalysts and H2O2 and also the amount of decline in chemical oxygen demand (COD) after the process were investigated. The concentration of PCP in the sample was determined using spectrophotometer at wavelength of 500 nm and, in the end, the results were analyzed using SPSS software and according to repeated measures analysis and statistical test of comparative ordered pairs with confidence interval of 95%. Scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD) images of modified pumice were taken and the kinetic degree of the processes was also determined. The results indicated that the PCP removal by the both processes increased with increasing reaction time, catalyst concentration, H2O2 concentration and pH and reduced with decreasing initial PCP concentration. The maximum removal efficiencies by the two processes: O3/nZrO2/H2O2 and O3/nTiO2/H2O2 were 100 and 95%, respectively, in the optimum conditions. The results illustrated that the two studied processes followed the pseudo-second -order kinetic model. Further, the findings revealed that the both processes mentioned in this study were of high capability in removing PCP and they could be used as an appropriate process in removing this organic material.