The performance and decolourization kinetics of O₃/H₂O₂ oxidation of reactive green 19 dye in wastewater

School of Environmental Engineering, Universiti Malaysia Perlis (UniMAP), Kompleks Pusat Pengajian Jejawi 3, 02600 Arau, Perlis, Malaysia.

^* Corresponding author: zulzikrami@unimap.edu.my

Abstract

The degradations characteristic of azo dye Reactive Green 19 (RG19) was investigated using advanced oxidation process (AOPs). It was evaluated based on colour and chemical oxygen demand (COD) removal. The effect of operational parameters such as initial dye concentration, initial dosage of hydrogen peroxide (H₂O₂), contact time, and pH was also being studied. The samples were treated by ozonation (O₃) and peroxone O₃/H₂O₂ process. Advanced oxidation processes (AOPs) involve two stages of oxidation; firstly is the formation of strong oxidant and secondly the reaction of organic contaminants in water. In addition, the term advanced oxidation is referring to the processes in which oxidation of organic contaminants occurs primarily through reactions with hydroxyl radicals. There are several analyses that use to determine the efficiency of the treatment process, which are UV-Vis absorption spectra, COD, Fourier Transform Infrared (FT-IR), and pH. The results demonstrated that the ozone oxidation was efficient in decolourization and good in mineralization, based on the reduction of colour and COD. Additionally, results indicate that H₂O₂ is able to perform better than ozonation in order to decolourize the dye wastewater with 0.5 mL H₂O₂/L dye dosage of H₂O₂ at different initial concentration, initial pH, with contact time.