Degradation of synthetic reactive Pyrazole-133 dye by using an advanced oxidation process assisted by gamma radiations

Abstract

This study investigated the degradation of the reactive dye RP-133 in aqueous solution using various hydrogen peroxide concentrations and gamma radiation doses (1–20 kGy). The solution's initial dye concentration and pH were optimized for the most effective degradation efficiency. The dye was treated with H₂O₂ and gamma radiation separately. At an acidic pH, an absorbed dose of 20 kGy, and 0.9 mL of H₂O₂, a 95% decomposition rate was achieved. FTIR analysis revealed differences in the functional groups of treated and untreated dye. Intermediates formed during degradation were identified using GC-MS. Hemolytic and Ames tests assessed the cytotoxicity and mutagenicity of the dye. Gamma radiation treatment significantly reduced both mutagenicity and cytotoxicity. Cytotoxicity decreased from 15.1% to 7.6%, and mutagenicity of bacterial strains TA98 and TA100 was reduced by 81.3% and 82.3%, respectively. The formation of low-molecular-weight organic acids further oxidized to carbon dioxide and water, indicating the efficiency of the advanced oxidation process. Combining gamma radiation with H₂O₂ effectively degraded RP-133, reducing its cytotoxicity and mutagenicity.