AWWA WQTC65768

The objectives of this study were to evaluate the application of ozone, hydrogen peroxide and ultraviolet radiation (AOP) process on the degradation of chlorpyrifos and to determine: the kinetics of chlorpyrifos photodegradation in ultraviolet/hydrogen peroxide (UV/H₂O₂) system; the rate constant of carbonate radicals and chlorpyrifos; and, the integration of carbonate radicals into the UV/H₂O₂ process of chlorpyrifos destruction. A collimated-beam UV reactor equipped with four low pressure (LP) mercury lamps (General Electric NO. G15T8) were used in the study. Incident irradiance was determined by a calibrated radiometer (IL1700, SED 240/W, International Light, Peabody, MA). Quantification of chlorpyrifos was carried out on a Varian Pro Star High Performance Liquid Chromatography (Varian, Inc., Palo Alto, CA) equipped with a 330 polychromatic diode array detector and C18 reverse phase column (7.5 x 150 mm). Chlorpyrifos concentration was determined with mobile phase of 80% CH₃CN in water with flow rate of 1ml min^-1 and absorbance detection at 275nm. Absorbance spectra were measured using a UV spectrophotometer- Cary Bio100 (Varian, Inc., Palo Alto, CA). Includes 9 references, figures.