Highly efficient chloramphenicol degradation by UV and UV/H2O2 processes based on LED light source

In this study, UV‐LED was employed as a novel light source to investigate the degradation of a representative antibiotic compound, chloramphenicol (CAP), in the absence or presence of H2O2. The UV‐LED irradiation showed a higher capability for degradation of CAP than conventional UV‐Hg vapor lamps. Effects of the initial CAP concentration, UV wavelength, and light intensity on the degradation of CAP by UV‐LED were evaluated. Introduction of H2O2 evidently enhanced the degradation efficiency of CAP due to the production of reactive hydroxyl radicals. Results showed that the UV‐LED/H2O2 removed CAP by up to 95% within 60 min at pH 5.0, which was twice as that achieved by the UV‐LED alone. The degradation products were identified to propose plausible degradation pathways. Moreover, the formation potentials of typical carbonaceous disinfection by‐products (C‐DBPs) and nitrogenous disinfection by‐products (N‐DBPs) were assessed for the CAP polluted water treated by the UV‐LED alone and UV‐LED/H2O2 processes. Results indicate unintended formation of certain DBPs, thereby highlighting the importance of health risk assessments before practical application. This study opens a new avenue for developing environment‐friendly and high‐performance UV‐LED photocatalytic reactors for abatement of CAP pollution in water. Practitioner points UV‐LED bore higher capability to degrade CAP than low‐pressure Hg lamp. The optimal performance to degrade CAP can be achieved at the UV wavelength of 280 nm. The degradation efficiency under UV‐LED/H2O2 process was double of that under UV‐LED process. TCM, DCAN, and TCNM formation were higher under the existence of UV‐LED radiation. The addition of H2O2 had greater influence on the formation of DCAcAm than the introduction of UV‐LED. Highly efficient chloramphenicol degradation was achieved by UV and UV/H2O2 processes based on LED light source and the importance of health risk assessments should be highlighted due to the unintended formation of DBPs.