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Dissolved organic nitrogen (DON) is an emerging concern in oxidative water treatment because it exerts oxidant demand and may form nitrogenous oxidation/disinfection by-products. In this study, we investigated the reactions of ozone with DON with a special emphasis on the formation of nitrate (NOT) and ammonium (NH4+). In batch ozonation experiments, the formation of NOT3- and NH4+ was investigated for natural organic matter standards, surface water, and wastewater effluent samples. A good correlation was found between NOT formation and the O-3 exposure (R-2 > 0.82) during ozonation of both model DON solutions and real water samples. To determine the main precursor of NON, solutions composed of tannic acid and model compounds with amine functional groups were ozonated. The NOT yield during, ozonation was significantly higher for glycine than for trimethylamine and dimethylamine. Experiments with glycine also showed that NOT was formed via an intermediate with a second-order rate constant of 7.7 +/- 0.1 M(-1)s(-1) while NH4+ was formed by an electron-transfer mechanism with O-3 as confirmed from a hydroxyl radical ((OH)-O-center dot) yield of 24.7 +/- 1.9%. The NH4+ concentrations, however, were lower than the OH yield (0.03 mol NH4+/mol center dot OH) suggesting other OH-producing reactions that compete with NH4+ formation. This study concludes that NOT formation during ozonation of DON is induced by an oxygen transfer to nitrogen forming hydroxylamine and oxime, while NH4+ formation is induced by electron transfer reactions involving C-centered radicals and imine intermediates. (C) 2016 Elsevier Ltd. All rights reserved.

© 2019. This is the peer reviewed version of the following article: Luigi Rizzo, Sixto Malato, Demet Antakyali, Vasiliki G. Beretsou, Maja B. Đolić,Wolfgang Gernjak, Ester Heath, Ivana Ivancev-Tumbas, Popi Karaolia, Ana R. Lado Ribeiro, Giuseppe Mascolo, Christa S. McArdell, Heidemarie Schaar, Adrián M.T. Silva, Despo Fatta-Kassinos(2019): Consolidated vs new advanced treatment methods for theremoval ofcontaminants of emerging concern from urban wastewater. Science of the Total Environment, 655 (2019) 986-1008, which has been published in final form athttps://doi.org/10.1016/j.scitotenv.2018.11.265. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0, 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.

Forward osmosis (FO) is known to be particularly efficient at treating impaired water sources with a high fouling potential. In the context of water reuse FO is being introduced as a robust pre-treatment process, usually as a first barrier prior to a reverse osmosis (RO) step. The commercialisation of FO however hinges on the development higher permeability membranes and a recent breakthrough came with the introduction of thin-film composite (TFC) membranes. While promising state-of-the-art TFC membranes have been successfully fabricated and tested at the pilot-scale, their performance in FO is yet to be determined by comprehensive characterisation under the changed, elevated transmembrane water flux conditions. In this thesis mass transport through novel TFC membranes was initially studied and modelled using two FO-only characterisation methods. Alginate fouling in novel TFC membranes was then examined under different driving forces. L'osmosi directa (OD) és particularment eficaç en tractar aigües residuals amb un alt potencial de contaminació i embrutiment. En el context de la reutilització de l'aigua, la OD s'està introduint com un procés de tractament robust, generalment abans d'una etapa d'osmosi inversa (OI). No obstant això, la comercialització de la OD depèn del desenvolupament de membranes de major permeabilitat. Un avanç recent es va produir amb la introducció de membranes thin-film composite (TFC). Tot i que les membranes de TFC s'han fabricat i provat amb èxit a escala pilot, el seu rendiment en OD encara no s'ha determinat mitjançant una caracterització completa amb condicions de flux d'aigua elevat. En aquesta tesi, el transport de massa a través de les noves membranes de TFC s'ha estudiat i modelatge inicialment utilitzant dos mètodes de caracterització d'OD. També en aquest estudi es va examinar l'embrutiment d'alginat de les noves membranes de TFC sota diferents forces impulsores (pressió osmòtica i pressió hidràulica.

Stormwater is a major driving factor of aquatic ecosystem degradation as well as one of the largest untapped urban freshwater resources. We present results from a long-term, multi-catchment study of urban stormwater pesticides across Australia that addresses this dichotomous identity (threat and resource), as well as dominant spatial and temporal patterns in stormwater pesticide composition. Of the 27 pesticides monitored, only 19 were detected in Australian stormwater, five of which (diuron, MCPA, 2,4-D, simazine, and triclopyr) were found in >50% of samples. Overall, stormwater pesticide concentrations were lower than reported in other countries (including the United States, Canada and Europe), and exceedances of public health and aquatic ecosystem standards were rare (10% of samples). Spatio-temporal patterns were investigated with principal component analysis. Although stormwater pesticide composition was relatively stable across seasons and years, it varied significantly by catchment. Common pesticide associations appear to reflect 1) user application of common registered formulations containing characteristic suites of active ingredients, and 2) pesticide fate properties (e.g., environmental mobility and persistence). Importantly, catchment-specific occurrence patterns provide opportunities for focusing treatment approaches or stormwater harvesting strategies. Refereed/Peer-reviewed

Urban runoff usually contains significant amounts of organic and inorganic colloidal particles. Due to their high surface area and associated surface charges, these colloidal particles become a strong binding site and carriers for many contaminants found in the runoff. This paper presents a study on the physicochemical properties and behaviors of organic colloidal particles found in urban runoff under different simulated pH conditions. Four optical characterization techniques, namely (1) UV spectroscopy; (2) fluorescence spectroscopy; (3) size-exclusion chromatography with UV detector and (4) dynamic light scattering were used to examine and evaluate the colloidal properties and their behaviors. It was found that the colloidal particles under both acidic and alkaline conditions exhibited a distinct bimodal characteristic in particle-size distribution. Parallel interpretation of the four optical characterization results revealed that the influence of pH on the colloidal particles were more prominent at alkaline conditions, where an enormous growth of larger colloidal particles was observed as a result of aggregation and/or dissolution of humics and fulvic-type substances as well as biopolymers and their precursors. Results showed that the colloidal particles behave differently under acidic, neutral and alkaline conditions. This has an important implication on the water quality and immediate water treatment processes are required.

Stormwater is one of the last major untapped urban water resources that can be exploited as an alternative water source in Australia. The information in the current Australian Guidelines for Water Recycling relating to stormwater harvesting and reuse only emphasises on a limited number of stormwater quality parameters. In order to supply stormwater as a source for higher value end-uses, a more comprehensive assessment on the potential public health risks has to be undertaken. Owing to the stochastic variations in rainfall, catchment hydrology and also the types of non-point pollution sources that can provide contaminants relating to different anthropogenic activities and catchment land uses, the characterisation of public health risks in stormwater is complex, tedious and not always possible through the conventional detection and analytical methods. In this study, a holistic approach was undertaken to assess the potential public health risks in urban stormwater samples from a medium-density residential catchment. A combined chemical-toxicological assessment was used to characterise the potential health risks arising from chemical contaminants, while a combination of standard culture methods and quantitative polymerase chain reaction (qPCR) methods was used for detection and quantification of faecal indicator bacteria (FIB) and pathogens in urban stormwater. Results showed that the concentration of chemical contaminants and associated toxicity were relatively low when benchmarked against other alternative water sources such as recycled wastewater. However, the concentrations of heavy metals particularly cadmium and lead have exceeded the Australian guideline values, indicating potential public health risks. Also, high numbers of FIB were detected in urban stormwater samples obtained from wet weather events. In addition, qPCR detection of human-related pathogens suggested there are frequent sewage ingressions into the urban stormwater runoff during wet weather events. Further water quality monitoring study will be conducted at different contrasting urban catchments in order to undertake a more comprehensive public health risk assessment for urban stormwater. Refereed/Peer-reviewed