Effect of pH on Photocatalytic Degradation of Cypermethrin in a Column Reactor Using Immobilized TiO2

Advanced oxidation process was used to remove both Cypermethrin and COD burden from the agricultural wastewater. It was shown that the normalized concentration of the pesticide was decreased to nearly zero during 3 hours. Operational conditions were pH=7 and 25C with the initial concentration of 75 ml (EC 40%) pesticide per 1000 liter water. Rate of concentration decrease was considerably faster through the first 30 minutes rather than final 30minutes. Additionally, in this research the amount of COD load in the neutral medium was reduced to 78% of its initial (COD0=7100gm/lit). The effect of pH on COD and concentration removal rate was studied. It was revealed that pH increase could grow the rate constant. COD and concentration removal was appropriately fitted with the pseudo first order kinetics model. Immobilization of TiO2 (Degussa, P-25) on the steel sieve plates has done by an low-cost and simple method. Uniform and proper distribution of TiO2 was proven by XRD analysis. Furthermore, insignificant rinse of photo-catalyst was displayed by SEM Image. Immobilized particles of titanium dioxide were exposed to UV radiation (Philips 15W – Wave length: 300-450nm) through the column reactor. Sampling was performed every 15 minutes during the experiment.