Large-scale raceway pond reactor for CEC removal from municipal WWTP effluents by solar photo-Fenton

Continuous flow solar photo-Fenton process has been carried out at demonstration scale at flow rates up to 18 m3 h−1 as an advanced treatment for the removal of contaminants of emerging concern, CECs. A 100-m2 raceway pond reactor, RPR, has been built in the WWTP of Almeria city, Spain. The fluid dynamics study showed plug-flow in the reactor channels and perfect mixing in the bends and paddlewheel sections, giving rise to long mixing times. Consequently, for CEC removal the RPR was operated in continuous flow mode at 1 h of hydraulic residence time and acidic pH, with 0.1 mM FeSO4 and 1.47 mM H2O2. Liquid depth was set at 10 cm in winter and 18 cm in summer, achieving > 85% of CEC removal in both cases. For the first time, CEC removal by solar photo-Fenton has been demonstrated under real operational conditions paving the way for its commercial application.