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Water ozonation is a standard process applied to reduce the concentration of the organic micropollutants’ (OMPs) in effluent. Since the ozonation is slow for many OMPs, it is desirable to increase the conversion of ozone to hydroxyl radicals, thus reducing its required dose. Likewise, membrane processes of different pore sizes and compositions can be used to reduce the concentration of OMPs in water. Recently, ceramic membranes (CMs) have gained increasing attention because they can provide long-term durability and filtration integrity. The aim of this study is to develop and implement a hybrid ozonation-filtration wastewater treatment process where their synergy will come into play in improving OMPs removal efficiency. In preliminary experiments, different metal oxides (α-Al2O3, γ- Al2O3, Mn2O3, CeO2, and TiO2) were used in batch experiments to test their catalytic activity towards heterogeneous ozonation, in the order to choose the most efficient one. Four commercial CMs with different compositions and pore sizes were used: three ultrafiltration (UF) ceramic membranes of TiO2/ZrO2 composition with 50 kDa, 150 kDa and 300 kDa molecular weight cut-off (MWCO) respectively, and a microfiltration (MF) ceramic membrane of TiO2/ZrO2+TiO2 composition with a pore size of 200 nm. The surface of the ceramic membranes was coated by with the most promising oxide using sol-gel method ; the modified membranes were analyzed by various techniques (XRD, SEM-EDS, AFM, BET). The characterizations were used to explain the behavior of the membranes in the presence of ozone. Such membranes will be used as a tool to increase the yield of hydroxyl radicals and thus, ensure increased removal or degradation of selected OMPs (mixture of amoxicillin, carbamazepine, ibuprofen and diclofenac) in the wastewater while reducing membrane fouling.

Wastewater reuse is considered as the most suitable and reliable alternative for sustainable water management and agricultural development [1] and membrane separation technology emerged as one of the tools to tackle the water stress problem. Ceramic membranes (CMs) offer durability and high integrity during filtration [2]. The most commonly used CMs for water treatment are alumina (Al2O3), titania (TiO2), zirconia (ZrO2), silicon carbide (SiC) and silica (SiO2) based. The structure and morphology of ceramic membranes have substantial effects on their performance. Based on their pore size, CMs could be classified into microfiltration (MF), ultrafiltration (UF) and nanofiltration (NF) with pore size ranging from > 50 nm, 2–50 nm and < 2 nm, respectively. In this study, four commercial CMs with different composition and pore size were used: three UF ceramic membranes of TiO2/ZrO2 composition with 50 kDa, 150 kDa and 300 kDa molecular weight cut-off (MWCO) respectively, and a MF ceramic membrane of TiO2/ZrO2+TiO2 composition with a pore size of 200 nm. The membranes were modified by sol-gel deposition of TiO2 [3] or CeO2 [4] film. One, two or three layers of each film were deposited on the each of the four membranes using the vacuum impregnation method to derive catalysts for application in hybrid ozonisationfiltration system. The composites were dried and subsequently thermally treated. Both the unmodified and surface-modified ceramics membranes were characterized in order to evaluate their chemical composition, phase composition, morphologic parameters, using scanning electron microscopy with energy dispersive X-ray spectroscopy, atomic force microscopy, nitrogen adsorption/desorption isotherms, X-ray diffraction analysis and Fourier transformed infrared spectroscopy.

Urban wet-weather discharges (combined sewer overflows, CSO and stormwater outlets from separate sewers, SWO) contain various trace contaminants which can pose a threat to receiving waters (Launay et al., 2016; Mutzner et al., 2020; Wicke et al., 2021). Hence, there is a need to identify critical contaminants and to quantify pollutant concentrations in wet-weather discharges to assess effective control strategies. Efforts have been made in the last decade to increase our understanding of the presence, magnitude, and diversity of contaminants in wet-weather discharges (e.g. Gasperi et al., 2014; Launay et al., 2016; Masoner et al., 2019; Mutzner et al., 2020; Rippy et al., 2017). Despite these efforts, the information gained with these monitoring campaigns is still limited, as most contain small, local datasets both in terms of sampled discharge events and spatial coverage. In this study, we use a data-driven statistical analysis of existing measurements collected at more than 60 wet-weather discharge sites to gain insight on the frequency of detection and relative abundance of trace contaminants. This information can be used to inform future monitoring efforts as utilities and regulators work towards building effective management strategies.

Comunicació de congrés presentada a: 16 th International Conference on Environmental Science and Technology, celebrat a l'Illa de Rodes (Grecia), del 4 a 7 de setembre de 2019 This work aims at integrating the last advances in high resolution mass spectrometry (HRMS) and statistical analysis of data to develop and optimize a smart methodology (workflow) for the assessment of the performance of innovative water treatments using different technological approaches based on advanced oxidation processes with UV-254nm: (i) UV/K2S2O8, where oxidation takes place mainly following the initial formation of sulfate radicals, (ii) UV/KHSO5, where oxidation begins with the formation of both sulfate and hydroxyl radicals and (iii) UV/H2O2, when only the formation of hydroxyl radicals takes place initially. Experiments were carried out using secondary effluent from a local wastewater treatment plant. The developed workflow allows the evaluation of the treatments in terms of overall oxidation through the careful study of Van Krevelen diagrams, where all the masses of the HRMS chromatograms are considered. The potential formation of transformation products with sulfur due to the sulfate radicals was also evaluated using statistical tools based on the isotopic pattern and accurate mass. Finally, the behavior of a large number of micropollutants with a wide range of physicochemical properties was studied using suspect screening strategies This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement SMARTWORKFLOW (747698), the Spanish Ministry of Science and Innovation (grant number CTQ2015-69832-C4), and the Economy and Knowledge Department of the Catalan Government (Consolidated Research Group program: ICRATECH - 2017 SGR 1318 and ICRA-ENV - 2017 SGR 01124)

When ozonation is employed in advanced water treatment plants to produce drinking water, dissolved organic matter reacts with ozone (O3) and/or hydroxyl radicals (•OH) affecting disinfection byproduct (DBP) formation with subsequently used chlorine-based disinfectants. This study presents the effects of varying exposures of O3 and •OH on DBP concentrations and their associated toxicity generated after subsequent chlorination. DBP formation potential tests and in vitro bioassays were conducted after batch ozonation experiments of coagulated surface water with and without addition of tertiary butanol (t-BuOH, 10 mM) and hydrogen peroxide (H2O2, 1 mg/mg O3), and at different pH (6 – 8) and transferred ozone doses (0 – 1 mg/mg TOC). Although ozonation led to a 24 – 37% decrease in formation of total trihalomethanes, haloacetic acids, haloacetonitriles, and trihaloacetamides, an increase in formation of total trihalonitromethanes, chloral hydrate, and haloketones was observed. This effect however was less pronounced for samples ozonated at conditions favoring molecular ozone (e.g., pH 6 and in the presence of t-BuOH) over •OH reactions (e.g., pH 8 and in the presence of H2O2). Compared to ozonation only, addition of H2O2 consistently enhanced formation of all DBP groups (20 – 61%) except trihalonitromethanes. This proves that •OH-transformed organic matter is more susceptible to halogen incorporation. Analogously, adsorbable organic halogen (AOX) concentrations increased under conditions that favor •OH reactions. The ratio of unknown to known AOX, however, was greater at conditions that promote direct O3 reactions. Although significant correlation was found between AOX and genotoxicity with the p53 bioassay, toxicity tests using 4 in vitro bioassays showed relatively low absolute differences between various ozonation conditions.

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