Photodegradation of fenitrothion in water under direct and indirect conditions

Document Type : Original Article

Authors

Pesticides Department, Fac. of Agric. Kafr El-Sheikh, Tanta Univ., Egypt.

10.21608/jpces.2005.459504

Abstract

Photodegradation kinetics of the insecticide fenitrothion (O, O-dimethyl O-4-nitro-m-tolyl phosphorothioate) at 5ppm level in water was carried out under direct and indirect photolysis (nitrate addition). The rate of loss of fenitrothion concentration with irradiation time using solar simulator was measured by HPLC. Loss of dissolved organic carbon (DOC) and inorganic ions (sulfate nitrite) formation rates were analyzed to confirm the photodegradation kinetics of fenitrothion using solar simulator followed by a total organic carbon (TOC) analyzer and ion chromatography. The results showed that the degradation rate of fenitrothion under indirect photolysis was faster than direct photolysis. The faster degradation rate of fenitrothion under indirect photolysis was attributed to the presence of nitrate which generates OH radicals and subsequently accelerates the degradation. This study reflected the significant influence of indirect photolysis in fenitrothion degradation kinetics.

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