Advanced water treatment with manganese oxide for the removal of 17α-ethynylestradiol (EE2)

Municipal wastewater is supposed to be one of the most important sources of endocrine-disrupting compounds (EDCs) in water. Therefore, advanced treatments and cost-efficient techniques should be developed to prevent the spread of this type of pollution into the environment. In this view, experiments were conducted in which the removal of 17α-ethynylestradiol (EE2), a synthetic and persistent estrogen, from water was monitored in three upstream bioreactors (UBRs), filled with, respectively, sand, granulated activated carbon (GAC) and MnO 2 granules. Tap water, spiked with 15,000 ng EE2/L was filtered through the reactors with a hydraulic retention time of approximately 1 h. The removal of EE2 in the sand, GAC and MnO 2 reactors was, respectively, 17.3%,>99.8% and 81.7%. The removal in the GAC reactor was mainly due to adsorption. The MnO 2 reactor, however, removed significantly more EE2 than could be predicted from its adsorption capacity, probably thanks to its catalytic properties. These catalytic properties could make it a cost-efficient technique for the removal of EE2, but further research at more environmentally relevant concentrations is needed.