Efficient optimization and mineralization of UV absorbers: A comparative investigation with Fenton and UV/H2O2

Abstract

UV absorbers developed for finishing of textile materials play a significant role in protection against UV radiations but their discharge in wastewater during processing and laundry action also retain serious concern to living species due to their recalcitrant nature. The current study examined the mineralization and degradation of two vinylsulfone and nitrogen (N-) containing UV absorber compounds (1a, 2a) via two effective Fenton and UV/H2O2 oxidation. The results showed that both the Fenton and UV/H2O2 processes mineralized the synthesized UV absorbers effectively; however the mineralization process with Fenton oxidation was more effective than the UV/H2O2. The mineralization of synthesized UV absorbers was affected by process parameters (dosage of Fe2+ and H2O2 pH and reaction time). Under attained optimum conditions of Fenton oxidation, dose of Fe2+ (15 mg/L), H2O2 (500 mg/L), pH (3.0) and contact time (120 minutes), 75.43 and 77.54% of Chemical Oxygen Demand removal was achieved for 1a and 2a, respectively. Whereas, the optimum conditions of UV/H2O2 process were H2O2 (700 mg/L), pH(3.0) and irradiation time (200 minutes) that brought 54.33 and 57.65% COD removal in case of 1a and 2a, respectively. The results indicated that the Fenton oxidation can be successfully employed for the mineralization of triazine based UV absorbers.