Emerging investigators series: comparative study of naproxen degradation by the UV/chlorine and the UV/H₂O₂ advanced oxidation processes

Abstract

The UV/chlorine and UV/H2O2 AOPs on the degradation of naproxen were compared. The efficiency of naproxen was much higher by UV/chlorine compared to UV/H2O2 under all the tested conditions. ClO˙ and CO3˙− played important roles in the degradation of naproxen.

State of the Art of UV/Chlorine Advanced Oxidation Processes: Their Mechanism, Byproducts Formation, Process Variation, and Applications

“…The V. fischeri toxicity was decreased by UV/chlorine treatment in three researches [72][73][74]. However, an increase in toxicity was reported in the rest of three [21,37,40]. One of reasons of the discrepancy may be treatment time in UV/chlorine AOPs.…”

“…However, part of them are decomposed by a prolonged operation of UV/chlorine process [21,53,60], which will result in a decrease in toxicity. In fact, a temporal increase and following decrease in V. fischeri toxicity was observed in all researches where a negative effect of UV/chlorine treatment on the toxicity removal was reported [21,37,40].…”

“…Some researchers applied this method for UV/chlorine AOPs to estimate the contribution of reactive species [20,23,31,37,40]. However, the addition of chemical probes affects both the degradation rate of pollutant and the steadystate concentration of reactive species through competitive consumption of reactive species.…”

“…One of reasons of the discrepancy may be treatment time in UV/chlorine AOPs. In researches with reduction in V. fischeri toxicity, the treatment time was not shorter than 1 h [72][73][74], whereas the treatment time was set at 13 min or shorter in the research with the increase in the toxicity [21,37,40]. In UV/chlorine AOPs chlorinated organic byproducts are temporally produced.…”

“…naproxen UV/chlorine increase in inhibition (46 → 57%) by 12 min treatment [40] luminescence inhibition (Photobacterium phosphoreum)…”