Continuous flow photoelectrocatalysis/reverse osmosis hybrid reactor for degradation of a pesticide using nano N-TiO₂/Ag/Ti electrode under visible light

In this work, a continuous flow hybrid reactor consisting of visible light photoelectrocatalytic (PE) and reverse osmosis (RO) processes was set for removal of diazinon pesticide from water using nano N-TiO₂/Ag/Ti electrode. First, Ag and N-TiO₂ nanoparticles were synthesized and simultaneously immobilized on a titanium grid sheet using electrophoretic deposition method to prepare a conductive catalyst. The morphology and composition of the resulting catalyst were characterized by SEM, DRS and XRD. Ability of the prepared catalyst and the effect of operation variables on the degradation of diazinon were investigated using the PE process under the visible light. According to the results, the maximum diazinon degradation efficiency was obtained at pH of 7.5, using 10 wt.% Ag:N-TiO₂ ratio, three N-TiO₂/Ag/Ti electrodes, visible light intensity of 21 mW cm⁻², Na₂SO₄ as supporting electrolyte and bias potential of 0.9 V. Finally, the N-TiO₂/Ag/Ti electrode was used in continuous flow PE/RO reactor for more degradation of diazinon. COD removal results showed 87.5% mineralization of diazinon.