Evaluation of operational parameters involved in solar photo-Fenton degradation of a commercial pesticide mixture

Photo-Fenton degradation of a mixture of commercial pesticides typically used in greenhouse agriculture, Vydate® (10% oxamyl), Metomur® (20% methomyl), Couraze® (20% imidacloprid), Ditimur-40® (40% dimethoate) and Scala® (40% pyrimethanil), has been evaluated. The experiments were performed at an original dissolved organic carbon of 200 mg/L (40 mg/L of each commercial pesticide). A battery of degradation studies was carried out under sunlight at the Plataforma Solar de Almeria in a pilot plant specially developed for photo-Fenton applications. Photo-Fenton efficiency gradually rose with temperature. Nevertheless, at 50 °C there was a decrease in efficiency. The influence of Cl− and SO42− between 100 and 2000 and 50 and 500 mg/L, respectively, was also analyzed. A central composite experimental design and its surface response analysis were employed to study the effect of these anions.