Aquatic photolysis of carbamazepine by UV/H2O2 and UV/Fe(II) processes

作者:Liu, Ning*; Zheng, Ming; Sijak, Sasa; Tang, Liang; Xu, Gang; Wu, Minghong
来源:Research on Chemical Intermediates, 2015, 41(10): 7015-7028.
DOI:10.1007/s11164-014-1795-2

摘要

In this work, the degradation of carbamazepine (CBZ) in water by UV/H2O2 and UV/Fe(II), two UV-based photolysis processes, was investigated. The addition of H2O2 and Fe(II) significantly improved the CBZ decomposition rate relevant to UV treatment alone. For UV/H2O2 photolysis, CBZ photodegradation followed pseudo-first-order kinetics. The rate of CBZ degradation increased with the increase of H2O2 concentrations and the decrease of initial CBZ concentrations. CBZ oxidation rates in sea water and surface water were lower than that in pure water and the maximum CBZ degradation occurred at pH 7. Additionally, both Cl- and HCO3 (-) could inhibit the CBZ decomposition in UV/H2O2 photolysis. For the UV/Fe(II) system, CBZ photodegradation also showed pseudo-first-order kinetics. The results showed that the degradation increased as the initial Fe(II) concentration increased up to a certain limit at which Fe(II) reduced the degradation by scavenging the . O-2 was favorable for CBZ degradation in UV/Fe(II) process. Finally, major degradation products of CBZ, including degradation intermediates, organic acids, and inorganic ions were detected by LC/MS/MS and IC. Based on the LC/MS/MS and IC analysis, the possible degradation pathways of CBZ photolysis were proposed. Results demonstrated that UV/H2O2 and UV/Fe(II) were both potential technologies for water treatment containing CBZ. However, considering the energy consumption, UV/Fe(II) was more efficient than UV/H2O2 process for CBZ degradation.