Potential degradation of norfloxacin using UV-C/Fe2+/peroxides-based oxidative pathways

The removal of norfloxacin (NOR), a widely used pharmaceutical and emerging water pollutant, was studied using UV-C and Fe2+ catalyzed peroxides-based oxidative processes (e.g., UV-C/Fe2+/H2O2, UV-C/Fe2+/S2O82- and UV-C/Fe2+/HSO5-) and compared with UV-C and UV-C/Fe2+. The UV-C and UV-C/Fe2+ degraded NOR to 38 and 55 %. However, use of peroxides, i.e., H2O2, S2O82-, HSO5- with UV-C and UV-C/Fe2+ promoted NOR % degradation to 75, 83, and 90 % using [peroxides](0) = 50 mg/L, [Fe2+](0) = 1 mg/L, and [NOR](0) = 10 mg/L, respectively. The significant impact of peroxides on NOR degradation was due to their decomposition into (OH)-O-center dot and SO4 center dot-. which showed high activity towards NOR degradation. The (OH)-O-center dot and SO4 center dot-. formation from peroxides decomposition and their contribution in NOR degradation was verified by different scavenger studies. Among the UV-C/Fe2+/peroxides processes, UV-C/Fe2+/HSO5- showed better performance. The changing concentrations of peroxides, Fe2+, and NOR affected degradation of NOR. The use of different pH and inorganic anions also influenced NOR degradation. The degradation pathways of NOR were established and analyzed acute as well as chronic toxicities of NOR and its DPs.

Automated summary

The removal of norfloxacin, a widely used pharmaceutical and emerging water pollutant, was studied using various oxidative processes. The use of peroxides, in conjunction with UV-C and UV-C/Fe2+, significantly enhanced the degradation of norfloxacin. Among the processes tested, UV-C/Fe2+/HSO5- showed the best performance.