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In view of promising efficiency of advanced oxidation process, ZnO/UV/H2O2 based advanced oxidation process (AOP) was employed for the degradation of Disperse Red-60 (DR-60) in aqueous medium. The process variables such as concentration of catalysts, reaction time, pH, dye initial concentration and H2O2 dose were evaluated for maximum degradation of dye. The maximum degradation of 97% was achieved at optimum conditions of H2O2 (0.9 mL/L), ZnO (0.6 g/L) at pH 9.0 in 60 min irradiation time. The analysis of treated dye solution revealed the complete degradation under the effect of ZnO/UV/H2O2 treatment. The water quality parameters were also studied of treated and un-treated dye solution and up to 79% COD and 60% BOD reductions were achieved when dye was treated with at optimum conditions. The dissolved oxygen increased up to 85.6% after UV/H2O2/ZnO treatment. The toxicity was also monitored using hemolytic and Ames tests and results revealed that toxicity (cytotoxicity and mutagenicity) was also reduced significantly. In view of promising efficiency of UV/H2O2/ZnO system, it could possibly be used for the treatment of wastewater containing toxic dyes.

In view of promising efficiency of advanced oxidation process (AOP), gamma radiation in combination with H2O2 was employed for the degradation of disperse red 73 (DR73) dye. Cs-137 gamma radiation source was used for dye aqueous solution irradiation. The process variables such as pH (3–9), H2O2 concentration (0.3–0.9 mL), gamma radiation absorbed dose (1–20 kGy) and DR73 initial concentration (50–150 mg/L) were optimized for maximum degradation of dye. The efficiency of AOP was evaluated on the basis of dye degradation, water quality parameters and toxicity reduction. Degradation of DR73 was achieved 69% using gamma radiation absorbed dose of 20 kGy and at the same dose 96.3% degradation was achieved in the presence of 0.9 mL/L H2O2. The dye degradation found to be dependent on dye initial concentration and pH of the medium. The radiolytic progress of DR73 was monitored by Fourier transform infrared (FTIR) and UV-Visible spectroscopy. The chemical oxygen demand (COD) and biological oxygen demand (BOD) were reduced significantly in response of treatment of dye at optimum conditions of process variables. The toxicity of treated and un-treated dye solution was monitored by haemolytic and Ames assays. Results revealed that the toxicity of DR73 dye was also reduced significantly after treatment. Findings revealed that the gamma radiation based AOPs are promising and could possibly be used for the remediation of textile wastewater contains toxic dyes.