RT info:eu-repo/semantics/article T1 Photolytic and photocatalytic removal of a mixture of four veterinary antibiotics A1 Zambrano, Johanna A1 García Encina, Pedro Antonio A1 Jiménez Sevilla, Juan José A1 López Serna, Rebeca A1 Irusta Mata, Rubén K1 Photodegradation K1 Fotodegradación K1 Veterinary antibiotics K1 Antibióticos para animales AB The removal of a mixture of four veterinary antibiotics (VA) – tetracycline (TET), ciprofloxacin (CIP), sulfadiazine (SDZ) and sulfamethoxazole (SMX) – via photo-degradation (UVC) and photocatalysis with TiO2 (UVC/TiO2) was investigated in a batch reactor under different initial concentrations (20, 100, 500 and 1000 μg/L per antibiotic). Ultra-high performance liquid chromatography coupled to a mass spectrometry (UHPLC-MS/MS) was used to determine the removal of these veterinary antibiotics. The removal of all antibiotics via photolysis was around 98–99% after 100 h for TET, 122 h for CIP, 212 h for SDZ and 240 h for SMX. Nevertheless, the removal of all antibiotics via photocatalysis was around 99–100% after 4.2 h for TET, 3.5 h for CIP, 7.1 h for SDZ and 16.5 h for SMX. The photolysis for the four veterinary antibiotics followed a first-order irreversible kinetic model. The photocatalysis of TET, CIP and SDZ followed a Langmuir-Hinshelwood kinetic model, and adsorption was considered the limiting step. SMX followed a first-order irreversible kinetic model. The photolytic degradation rate constant (k1) was 0.00073 min−1 for TET, 0.00055 min−1 for CIP, 0.00031 min−1 for SDZ and 0.00027 min−1 for SMX. While for photocatalysis k1 was 0.0044 min−1 for SMX; kL-H was 0.0284 min−1 for TET, 0.0379 min−1 for CIP and 0.0141 min−1 for SDZ. The VA degradation was enhanced by the use of a catalyst. Additionally, electrical energy per order (EEO) was assessed to estimate the electrical energy efficiency of each process. EEO values for photolysis were 339.06 kWh/m3/order for TET, 449.84 kWh/m3/order for CIP, 795.31 kWh/m3/order for SDZ and 897.71 kWh/m3/order for SMX. On the other hand, EEO values for photocatalysis were 14.96 kWh/m3/order for TET, 12.07 kWh/m3/order for CIP, 20.39 kWh/m3/order for SDZ and 62.10 kWh/m3/order for SMX. The energy consumption for photocatalysis was considerably lower than for photolysis. This study determined an overall degradation rate constant for a wide range of TET, CIP, SDZ and SMX concentrations. Furthermore, when working with a pH of 8 (a typical pH from wastewater from livestock farms) and a VA mixture whose concentrations resemble the characteristics of real water samples, that photolysis and photocatalysis are potential processes for wastewater treatment with low energy consumption. PB Elsevier SN 2214-7144 YR 2022 FD 2022 LK https://uvadoc.uva.es/handle/10324/57511 UL https://uvadoc.uva.es/handle/10324/57511 LA eng NO Journal of Water Process Engineering, 2022, vol. 48, 102841 NO Producción Científica DS UVaDOC RD 22-nov-2024