Comparison of UV, UV/H2O2 and ozonation processes for the treatment of membrane distillation concentrate from surface water treatment: PhACs removal and environmental and human health risk assessment

Abstract

This study aimed at the assessment of UV, UV/H2O2 and ozonation processes on the removal of 26 pharmaceutically active compounds (PhACs) from a membrane distillation (MD) surface water concentrate. Furthermore, environmental and human health risk assessment were carried out considering acute and chronic risks, in addition to the genotoxic and carcinogenic effect over human health upon exposure. PhACs rejection by MD was >99% at 80% recovery rate. Besides PhACs rejection, MD was able to reject solids and other ions. Regarding the PhACs degradation in the concentrate, an increase in efficiencies were observed for UV/H2O2 and ozonation while increasing hydrogen peroxide dosage or ozone flow rate, respectively, achieving efficiencies up to 99.9%. Prednisone, Atorvastatin and Clarithromycin, considered the most insoluble PhACs among all, presented the lowest kinetic constants. Furthermore, these advanced oxidative processes (AOPs) were capable to effectively reduce the effluent color, total nitrogen and total organic carbon. Lastly, the surface water was subject to high toxicological risk. After the concentrate treatment by AOPs, acute and chronic effects were reduced while increasing H2O2 and O3 dosage in the UV/H2O2 and ozonation process.