Gamma radiation-induced degradation of Acid Violet 49 in the presence of hydrogen peroxide (H₂O₂) in an aqueous medium

The present study is about the effect of gamma radiations on the degradation of Acid Violet 49 (AV49) in the presence of H2O2 (gamma/H2O2). The Cs-137 radiation source was calibrated to irradiate the aqueous solution of AV49 within the 1 kGy, 5 kGy & 10 kGy dose range. The results showed that 50-150 mg/L of AV49 was effectively degraded by gamma radiation (85 %), however, the concentration of H2O2 in the range of 0.2-0.6 mL promoted degradation to 90 % and 98 %, respectively. It was observed that all absorption bands declined with rising irradiation dose and disappeared completely after 10 kGy applied dose. pH conditions (3, 5,7, and 9) were used in the radio-lytic degradation of AV49, the results showed that the best degradation efficiency has been found for pH 9. The optimum degradation rate is higher (98 %) with a 50 mg/L concentration of AV49, 0.6 mL H2O2, and pH 9 at a 10 kGy absorbed dose. In addition, the influence of various parameters on the rate of degradation such as the effect of irradiation dose, pH, H2O2, and dye (AV49) concentration was also studied. Furthermore, the removal of total organic carbon TOC was not as effective as that of the AV 49. Total nitrogen TN was not completely removed even at high dosage. Radio-lytic degradation of AV49 was analyzed by using Fourier transform infrared spectroscopy (FTIR) and liquid chromatography coupled to mass spectrometry (LC-MS) as an analytical technique. Results revealed that the proposed methodology for degradation of dyes is effective and probably could be applied for the removal of other toxic pollutants.