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The degradation of two organic pollutants (amoxicillin and diclofenac) in 0.1 mM aqueous solutions was studied by using advanced oxidation processes, namely ozonation, photolysis, photolytic ozonation, photocatalysis and photocatalytic ozonation. Diclofenac was degraded quickly under direct photolysis by artificial light (medium-pressure vapor arc, λ exc > 300 nm), while amoxicillin remained very stable. In the presence of ozone, regardless of the type of process, complete degradation of both organic pollutants was observed in less than 20 min. Photolysis or ozonation on their own led to modest values of total organic carbon (TOC) removal (<6% or 41%, respectively in 180 min), while for photocatalysis (no ozone present) a significant fraction of nonoxidizable compounds remained in the treated water (∼15% after 180 min). In the case of photolytic ozonation, the kinetics of TOC removal was slow. In contrast, a relatively fast and complete mineralization of amoxicillin and diclofenac (30 and 120 min, respectively) was achieved when applying the photocatalytic ozonation process. The absence of toxicity of the treated waters was confirmed by growth inhibition assays using two different microorganisms, Escherichia coli and Staphylococcus aureus . Photocatalytic ozonation was also applied to an urban wastewater spiked with both amoxicillin and diclofenac. The parent pollutants were easily oxidized, but the TOC removal was only as much as 68%, mainly due to the persistent presence of oxamic acid in the treated sample. The same treatment allowed the effective degradation of a wide group of micropollutants (pesticides, pharmaceuticals, hormones and an industrial compound) detected in non-spiked urban wastewater. [ABSTRACT FROM AUTHOR]

Abstract Urban wastewater treatment plants (WWTPs) are among the main anthropogenic sources for the release of contaminants of emerging concern (CECs) into the environment, which can result in toxic and adverse effects on aquatic organisms and consequently on humans. Unfortunately, WWTPs are not designed to remove CECs and secondary (e.g., conventional activated sludge process, CAS) and tertiary (such as filtration and disinfection) treatments are not effective in the removal of most CECs entering WWTP. Accordingly, several advanced treatment methods have been investigated for the removal of CECs from wastewater, including consolidated (namely, activated carbon (AC) adsorption, ozonation and membranes) and new (such as advanced oxidation processes (AOPs)) processes/technologies. This review paper gathers the efforts of a group of international experts, members of the NEREUS COST Action ES1403 who for three years have been constructively discussing the state of the art and the best available technologies for the advanced treatment of urban wastewater. In particular, this work critically reviews the papers available in scientific literature on consolidated (ozonation, AC and membranes) and new advanced treatment methods (mainly AOPs) to analyse: (i) their efficiency in the removal of CECs from wastewater, (ii) advantages and drawbacks, (iii) possible obstacles to the application of AOPs, (iv) technological limitations and mid to long-term perspectives for the application of heterogeneous processes, and (v) a technical and economic comparison among the different processes/technologies. Graphical abstract Unlabelled Image Highlights • Adsorption, O 3 , NF and RO membranes filtration can effectively remove CECs. • (Solar driven) AOPs appear competitive for CECs removal from urban wastewater. • When applying O 3 or AOPs ecotoxicological studies should be performed. • Lack of comparative investigations between consolidated and new processes • Conclusive evaluation of the most suitable and cost effective solution/s not yet possible [ABSTRACT FROM AUTHOR]