Parametric Study on Photocatalytic Dye Degradation under Visible Light in Flat Slurry Reactor with nano-ZnO Photocatalyst

Abstract

A simple rectangular shape photoreactor of 10-L capacity was fabricated in glass plates. The performance of the reactor in the degradation of Orange M2R dye was evaluated under sunlight with ZnO as a photocatalyst. The Orange M2R dye was selected in the study as it is used for the fabric dying. Analytical reagent grade ZnO was used as photocatalyst as it displayed higher photocatalytic activity than synthesized ZnO. The degradation study of dyes was performed under sunlight. The pH of the dye solution, catalyst dose, and height of the dye solution in the reactor were identified as crucial experimental parameters affecting the dye degradation. The pseudo first-order decolourisation rate constant under optimized reaction conditions was evaluated by applying the Langmuir–Hinshelwood equation. Mineralization of the dye was accounted in terms of chemical oxygen demand. Furthermore, a flat slurry reactor-based process was applied for the degradation of dyes from the actual effluent and found effective.