Removal of Diclofenac, Ketoprofen, and Carbamazepine from Simulated Drinking Water by Advanced Oxidation in a Model Reactor

Abstract

The objective of this study was to examine the degradation of pharmaceutical compounds diclofenac, ketoprofen, and carbamazepine in a bench-scale batch type advanced oxidation treatment system combining non-thermal plasma and UV photocatalysis. The key factors affecting pollutant decomposition were studied in a dielectric barrier discharge (DBD) plasma reactor. This was followed by the comparative assessment of various advanced oxidation processes (O3; UV+O3; TiO2+O3; TiO2+UV+O3) in a UV-photocatalysis reactor. The overall effectiveness of the treatment process was established according to the decomposition efficiency of the individual compound determined by high-performance liquid chromatography with ultraviolet detection (HPLC/UV), removal of total organic carbon (TOC), energy consumption, and acute toxicity test with Chironomus sp. larvae. Depending on the pharmaceutical compound and oxidation system, complete decomposition of the target compound was reached within 3–6 min. The TOC removal ranged between 25 and 100% with energy consumption varying 3.1–10.6 MJ/g. TiO2+UV+O3 revealed slightly higher toxicity of treated water as compared to TiO2+O3 (22–50% vs 17–33% mortality rate of Chironomus sp. larvae). TiO2+O3 and TiO2+UV+O3 systems proved as an efficient combination of AO processes for the decomposition of pharmaceuticals in water, as long as the treatment duration is sufficient to fully mineralize organic substances.