Photocatalytic Degradation of Diazinon in Aqueous Solutions Using Immobilized MgO Nanoparticles on Concrete

Abstract

Abstract Photocatalytic degradation of diazinon in the aqueous solution using UV light and MgO nanoparticle (NPs) immobilized on the concrete was investigated. Prepared catalyst was characterized using TEM, XRD, SEM, and EDX techniques. The results showed that the average particle size of immobilized MgO NPs was 38.3 nm and NPs appropriately was coated on the concrete surface. The performance of degradation and mineralization of diazinon was evaluated by HPLC and TOC techniques, respectively. The effect of operational parameters including pH value, initial pesticide concentration, and contact time were studied on the removal and mineralization of diazinon by a photocatalytic process. The results showed that the MgO NPs and UV light had little effect in removing pesticide when used individually. On the other hand, diazinon can be effectively degraded by immobilized MgO NPs in the presence of UV light. Degradation products of diazinon using the proposed photocatalytic technique were identified by the GC-MS analysis. The maximum diazinon removal (99.46 %) was obtained under the conditions; pH 7, diazinon concentration of 5 mg/L, and contact time of 120 minutes. Also, the lowest energy consumption conditions were as follow; pH 7, diazinon concentration of 5 mg/L, and contact time of 30 minutes.