Ibuprofen and Naproxen removal from domestic wastewater using a Horizontal Subsurface Flow Constructed Wetland coupled to Ozonation

Abstract Pharmaceutical compounds have been introduced into aquatic ecosystems by diverse sources and routes, which could lead to potential negative consequences for the environment and human health. The main incorporation route of these compounds is the Wastewater Treatment Plants effluents, due to its low removal efficiency to treat these types of pollutants. Coupled systems between biological treatments and Advance Oxidation Processes emerge as an alternative to reduce costs and obtain high removal efficiencies of these types of substances. In this study, the removal efficiency of micropollutants such as Ibuprofen and Naproxen using a coupled system between a Horizontal Subsurface Flow Constructed Wetland planted with Cyperus ligularis and an Ozonation reactor was evaluated. Three Ozone doses (10, 15 and 21 mg/L) were assessed as explanatory variable and the experiment was performed in six set of samples. In addition, Dissolved Organic Carbon (DOC), Total Nitrogen (TN) and in situ variables such as pH, Turbidity, Dissolved Oxygen, Redox Potential, Electric Conductivity and Temperature were monitored as Covariates. The main results revealed that overall removal efficiency averaged 97.2% and ≥97.3% for Ibuprofen and Naproxen respectively, using the medium Ozone dose (15 mg.L −1 ) were obtained. Results indicated that there were no significant differences (P > 0.05) between the ozone doses used, whereas significant statistical differences were found between coupling performance and individual technologies. Likewise, the coupled system demonstrated versatility regarding organic matter and nitrogen removal, with performances above to 70% and 50% in terms of DOC and TN, respectively.