查看文章

Roxarsone (ROX) and nitarsone (NIT) are used as additives in animal feeding operations and have been detected in animal manure, agricultural retention ponds, and adjacent surface waters. This work investigates treatment of organoarsenicals using UV-based treatment processes, namely UV irradiation at 253.7 nm and the UV-H 2 O 2 advanced oxidation process. The apparent molar absorptivity was mapped for ROX and NIT across pH and wavelength. For UV irradiation at 253.7 nm, the fluence-based pseudo-first order rate constant (k p′) and effective quantum yield (Φ) for ROX were 8.10–29.7× 10− 5 cm 2/mJ and 2.34–8.37× 10− 3 mol/E, respectively; the corresponding constants were slightly lower for NIT. The observed rate constants are higher during advanced oxidation (eg, k p, ROX′= 3.92 (±0.19)–217 (±48)× 10− 4 cm 2/mJ). Second order rate constants for organoarsenical transformation by hydroxyl …