Removal of a Pharmaceutical Mix from Urban Wastewater Coupling Membrane Bioreactor with Advanced Oxidation Processes

Abstract

Emerging contaminants are a global concern, as Directive 2013/39/UE shows. Given the possible consequences that may lead to the presence of these compounds in water resources, different proposals are being evaluated to avoid their discharge into the environment. This study focuses on the use of a biological and physicochemical combined treatment formed by a membrane bioreactor with an H2O2/UltraViolet (UV) advanced oxidation process coupled subsequently to degrade contaminants of emerging concern in real urban wastewater. The membrane bioreactor operated at 16 h of hydraulic retention time and 4,250 mg/L of mixed liquor suspended solids. Different hydrogen peroxide dosages (25, 50, and 100 mg/L) were tested in the photoreactor at 20°C and the natural pH of the wastewater. Different initial concentrations of a mix of pharmaceuticals (carbamazepine, ciprofloxacin, and ibuprofen) were tested. Removal efficiencies obtained in the biological stage ranged from 66.23%–96.18%, 90.63%–100%, and 90.04%–96.48%, respectively. However, complete removal was achieved after the physicochemical stage when the concentrations of contaminants in the mix were similar to current concentration levels in urban wastewater.