Solar photo-Fenton and UV/H2O2 processes against the antidepressant Venlafaxine in urban wastewaters and human urine. Intermediates formation and biodegradability assessment
In this work, the use of Advanced Oxidation Processes (AOPs) against the degradation of an emerging contaminant has been subjected under systematic investigation. The optimization of treatment of the anti- depressant drug Venlafaxine (VFA) was performed, using UV light, the combined UV/H2O2 process, solar light, Fenton and finally the solar photo-Fenton process in laboratory scale. The degradation kinetics, the time necessary to remove 90% of the contaminant and the optimal reactants concentration were proposed. The treatment in pure water, (synthetic) wastewater and urine was assessed, in an effort to identify the opportunities and pitfalls the application of process would encounter in a field application. Treatment by the UV-based methods was found sufficiently efficient and the application of the solar photo-Fenton process showed feasibility in a potential field application with appropriate context. Real urban wastewater effluents after biological and physicochemical treatment were tested, as well as human urine, as a proposal for on-site collection and treatment was also treated. Biological treatment before applying the tested AOPs improved their efficiency, and the strategy of diluting urine prior to treatment greatly enhanced the efficacy of the process. Finally, the identification of the degradation pathway and the biodegradability tests of AOPs treated VFA solutions exhibit promising results concerning the strategy of treatment for similar pollutants of emerging concern.