Elimination of organic micro-contaminants in municipal wastewater by a combined immobilized biomass reactor and solar photo-Fenton tertiary treatment

Abstract Municipal wastewater treatment plants (MWTPs) have become one of the main sources of water for potential reuse. However, some pharmaceuticals, pesticides, hormones and others organics escape conventional wastewater treatments, and therefore, new technologies must be applied to overcome the problem. This article presents an efficient alternative that combines an aerobic immobilized biomass reactor (IBR) with a solar photo-Fenton process as a tertiary treatment. Real municipal wastewater was treated in the IBR system in batch and continuous modes. Micro-pollutants were monitored by using an advanced analytical procedure consisting of pre-concentration of samples by solid phase extraction (SPE) followed by liquid chromatography coupled to mass spectrometry. Results were compared with those observed in the MWTP secondary conventional activated sludge treatment. Effluents from the IBR, operating at the maximum treatment capacity, were treated in a previously optimized solar photo-Fenton pilot plant as a tertiary treatment to entirely eliminate remnant micro-pollutants.