Gamma and UV radiations induced treatment of anti-cancer methotrexate drug in aqueous medium: Effect of process variables on radiation efficiency evaluated using bioassays.

This studystudy focuses on the effect of radiation treatment and hydrogen peroxide (HO) on the toxicity of anticancer methotrexate. For cytotoxicity, different bioassays such as Allium cepa, hemolytic, brine shrimp were employed. The Ames test was used for mutagenicity analysis. The solutions having concentrations 5, 10 and 15 ppm were irradiated with UV radiation exposure time 15, 30, 45, 60, 75 and 90 min and gamma radiation absorbed doses 0.3, 0.6, 0.9, 1.2, 2, 3 and 4 kGy in combination with with HO. There was a clear difference observed for aqueous solution before and after treatment with reference to cytotoxicity and mutagenicity. In Allium cepa test, a 47.07, 44.36 and 38.23% increase in root length (RL), root count (RC) and mitotic index (MI) was observed, respectively, for UV/HO treatment and in the case of gamma/HO treatment, the RL, RC and MI were increased up to 49.39, 52.63 and 52.38%, respectively. Brine shrimp test has shown 85.95 and 91.30% decrease in toxicity using UV/HO and gamma/HO respectively, while hemolytic test has shown 19.21 and 26.32% hemolysis using UV/HO and gamma/HO, respectively. The mutagenicity reduced up to 82.3, 86.46 and 89.59% (TA98) and 85.42, 87.5 and 90.63% (TA100) for UV/HO while 89.59, 90.63 and 93.75% (TA98) and 84.38, 89.59 and 92.71% (TA100) for gamma/HO. The UV and gamma radiation along with HO based AOPs are promising approaches to detoxify the wastewater which can be extended to real hospital liquid effluent effectively.