Photocatalytic Degradation of Persistence Herbicide Fomesafen by Using ZnO/Na₂S₂O₈ as a Catalyst/Oxidant under UV radiation

In the present investigation, the Photocatalysis of Fomesafen new class of diphenyl ether herbicide was investigated using ZnO nanoparticles at different pH 4, 7 and 9. In the present study, the optimum amount of the catalyst was used for the photocatalysis, effect of UV light, effect of aeration and effect of the addition of oxidant to the reaction mixture were studied. The ZnO nanoparticles were synthesized by Sol-gel process and characterized by SEM, TEM, and XRD. The fomesafen formulation of active strength 12.5% was used in this experiment. The rate of the reaction in this experiment was followed pseudo-first-order kinetics. The half-life values of fomesafen with ZnO/Na2S2O8 in three different pH solutions were 16.03, 15.56 and 11.93 hours respectively. The optimum amount of catalyst used for this study was 100 mg L-1. The rate of the reaction was rapid in basic pH than in the acidic and neutral pH values. The degradation was fast in the presence of sunlight and nanoparticles