Although the concentration of emerging organic micropollutants (OMPs) is considered quite low (usually ng L-1 to µg L-1) in domestic wastewater, their presence may result in harmful impacts of short, medium and long term on the ecosystem, human health and the economy. Most OMPs are not completely eliminated in conventional sewage treatment plants (STPs), such as activated sludge and UASB reactors, and the mechanisms involved in their elimination are still unclear. Understanding these mechanisms and the factors involved in the removal of these OMPs, such as sorption, biotransformation, redox potential, enzymatic activities, physicochemical characteristics, operating parameters of treatment systems, among others, is essential to mitigate the concentrations of these compounds in STPs. Anaerobic technology is widely used for both sewage treatment and sludge digestion around the world, but studies of biotransformation of OMPs in these systems are still incipient. Recent studies have pointed out that the different stages of anaerobic digestion may act differently on the biotransformation of OMPs. Facing this scenario, this research aims to establish a two-phase anaerobic treatment system (acidogenic-methanogenic) in order to optimize the OMPs removal in STPs. Nine target compounds of different classes and which are frequently detected in sanitary sewage were selected for the study: the antibiotics sulfamethoxazole and ciprofloxacin; the anti-inflammatory drugs ibuprofen, naproxen and acetaminophen; the surfactant nonylphenol; the parabens methylparaben and propylparaben; and the beta-blocker metoprolol. It is intended from this research also evaluate the sorption mechanisms of these OMPs onto biomass, obtain kinetic degradation parameters, identify the transformation products generated during the process and the microorganisms involved in the removal of these compounds.
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