Experimental Photodegradation of OPs and CBs by Advanced Oxidation Techniques in the Aqueous TiO2 Suspensions

Abstract

The reaction of pesticides with the OH radical, is the most dominant annihilation reaction of the atmosphere. Phosmet, Azamethiphos, Coumaphos and Temephos were used as organophosphorous pesticides, and Methiocarb, Carbofuran and Pirimicarb compounds were used as carbamate pesticides with the aim of investigating the kinetics of the reactions of Organophosphorous (OPs) and Carbamate (CBs) Pesticides with the OH radicals. In aqueous TiO2 suspensions, the degradation reactions via photocatalytic-effect of the seven pesticides selected as pollutants were analysed, and the impact of the initial concentration was calculated. All experiments were conducted in the same photoreactor and under the same conditions as three repetitions. The optimum amount of photocatalyst for the studied pesticide was determined and TiO2 concentration for all experiments were taken as 0.2 g/100 mL. Considering that organic pollutants are present in water in trace amount, the initial concentrations for all organic compounds were added so as to be1.0x10-4 molxL-1 , into the suspensions and the solution containing the organic pollutant. In this study, degradation speed of pesticides were determined experimentally, and the fastest degrading pesticide was tried to be found out.