Investigation of the Treatability of Diclofenac by Photochemical Advanced Oxidation Processes

Abstract

The drug selected in this study is diclofenac which has the highest acute toxicity among all of the anti-inflammatory drugs. In this study, UV was integrated with different oxidants (UV/H<inf>2</inf>O<inf>2</inf>, UV/TiO<inf>2</inf>, UV/ZnO), to study the removal efficiency of diclofenac. Synthetic wastewater containing diclofenac drug were treated with the help of UV, UV/H<inf>2</inf> O<inf>2,</inf> UV/TiO<inf>2</inf> and UV/ZnO methods by taking samples at different time intervals of 0-10-20-30-40-50-60 minutes. Different solutions of diclofenac were prepared with concentrations of, 50mg/L, >99.99mg /l, 200mg/L, 400mg/L and 800mg/L for treated with UV and UV/H<inf>2</inf>O<inf>2</inf> for UV/TiO<inf>2</inf> and UV/ZnO solutions were prepared with concentrations 40, 80, 160, 240 and 320mg/L. Diclofenac concentration was analyzed by Liquid Chromatography Mass Spectrometry (LCMS/MS) and organic pollutants were analyzed by Total Organic Carbon (TOK) device. The other operating conditions remained the same in all systems. In case of 200 mg/L, LC-MS/MS analysis showed UV removal efficiency was 55.23% and UV/H<inf>2</inf>O<inf>2</inf> removal was >99.99%. TOC results showed that 30.71% diclofenac removal with UV and 97% with UV/H<inf>2</inf>O<inf>2</inf> removal, in case of 800 mg/L concentration. In case of 320mg/L, TOC analysis showed that UV/TiO<inf>2</inf> and UV/ZnO processes removal efficiency were respectively 93.23% and 96.10%. LC-MS/MS analysis results showed that >99.99% removal efficiency at 240 mg/L in both of TiO<inf>2</inf> and ZnO concentrations. According to the results, while the effectiveness of the UV process alone is 10-30%, more effective removal efficiency (%60->99.99) was obtained in combinations such as UV/ZnO, UV/TiO<inf>2</inf>, UV/H<inf>2</inf>O<inf>2</inf>. In terms of cost, optimum process UV/H<inf>2</inf>O<inf>2</inf> (200 mg/L) process was found. © 2020, TUBITAK. All rights reserved.