DEGRADATION OF CONTAMINANTS OF EMERGING CONCERN IN A SECONDARY EFFLUENT USING SYNTHESIZED MOF-DERIVED PHOTOANODES: A COMPARATIVE STUDY BETWEEN PHOTO-, ELECTRO- AND PHOTOELECTROCATALYSIS

Three metal-organic framework (MOF)-based photoanodes were prepared by deposition on TiO 2 nanotubes using Ti as substrate (Ti/TiO 2 NT): i) Ti/TiO 2 NT-Au@ZIF-8, ii) Ti/TiO 2 NT-Ru 3 (BTC) 2 , iii) Ti/TiO 2 NT-UiO-66(Zr)NH 2 . These photoanodes were characterized by FEG-SEM, EDX and DRX. The analyses showed a successful modification and a high homogeneity of the different MOFs on the Ti/TiO 2 NT surface. The photoanodes were studied in the degradation of Contaminants of Emerging Concern (CECs) in a spiked secondary effluent from a Municipal Wastewater Treatment Plant (MWWTP). Sodium diclofenac (DCF), sulfamethazine (SMT) and carbamazepine (CBZ) were used as CECs at low concentration (200 μg/L each CEC). The samples were preconcentrated using Solid Phase Extraction (SPE) and analyzed by a HPLC-DAD system. The MOF-based photoanodes exhibited a high photoelectrochemical (PEC) activity towards the oxidation of CECs, achieving up to 50%, 70% and 80% of removal using Ti/TiO 2 NT-Au@ZIF-8, Ti/TiO 2 NT-UiO-66(Zr)NH 2 , Ti/TiO 2 NT-Ru 3 (BTC), respectively. The influence of the generation of hydroxyl radical was then studied. The results indicate that PEC degradation using Ti/TiO 2 NT-Ru 3 (BTC) 2 and Ti/TiO 2 NT-UiO-66(Zr)NH 2 is more affected by the concentration of the radical.