Periodic Reporting for period 2 - AQUAlity (Interdisciplinar cross-sectoral approach to effectively address the removal of contaminants of emerging concern from water)
Reporting period: 2019-10-01 to 2022-09-30
Access to water is recognized as a fundamental human right by the United Nations General Assembly, whereas the achievement of clean water and sanitation is one of the United Nations Sustainable Development Goals. The complex challenge of the production of safe and clean water requires different levels of action, which include the synthesis of green materials, the development of enhanced water treatment technologies, the implementation of effective legal tools against water pollution, the correct management of the present water treatment facilities.
A peculiar aspect related to water quality is represented by the so-called Contaminants of Emerging Concern (CECs), which are compounds derived from humans’ activities, detected at very low concentration level in natural water bodies. Today, there is increasing concern about the combined effects of this multitude of chemicals as they enter the environment and the food chain and a general consensus among policy-makers that emerging substances need to be addressed in a systematic and coherent manner.
The overall research goals of AQUAlity, a multidisciplinary and cross-sectoral European Training Network, are to generate and promote highly skilled scientists with the potential to face the present and future challenges concerning the protection of water resources from CECs and to achieve the environmentally sustainable removal of CECs from aqueous systems by conducting frontier research in the field of Advanced Oxidation Processes (AOPs), materials development and nanofiltration technology.
A peculiar aspect related to water quality is represented by the so-called Contaminants of Emerging Concern (CECs), which are compounds derived from humans’ activities, detected at very low concentration level in natural water bodies. Today, there is increasing concern about the combined effects of this multitude of chemicals as they enter the environment and the food chain and a general consensus among policy-makers that emerging substances need to be addressed in a systematic and coherent manner.
The overall research goals of AQUAlity, a multidisciplinary and cross-sectoral European Training Network, are to generate and promote highly skilled scientists with the potential to face the present and future challenges concerning the protection of water resources from CECs and to achieve the environmentally sustainable removal of CECs from aqueous systems by conducting frontier research in the field of Advanced Oxidation Processes (AOPs), materials development and nanofiltration technology.
1) We developed advanced analytical tools for the determination of CECs and we assessed their environmental fate. A list of 43 CECs worth to be investigated was selected using the NORMAN prioritization approach and 31 reliable analytical procedures were established for their determination, including their transformation products (TPs). The photochemical fate of the selected CECs was assessed in a variety of experimental conditions (natural and simulated solar irradiation, natural and wastewaters) by identifying their TPs, and by applying integrated toxicity approaches, so allowing to unravel their fate after discharge in the environment or upon treatment. Statistical and chemometric tools were constantly used to properly evaluate the analytical meaning of the measurements and to predict the best conditions to be applied for an efficient removal. Besides, a new software, namely SPIX, capable to follow the degradation of CECs, and the formation of TPs via high-resolution mass spectrometry (HR-MS) without a previous separation, has been developed and validated in actual waters, such as surface waters and wastewater.
The presence of new potentially hazardous compounds was assessed in two sampling campaigns performed on natural water and wastewaters sampled in four countries (Italy, France, Greece and Denmark). Untargeted analysis via HR-MS allowed recognizing 649 new CECs identified at level 2 and submitted to the NORMAN Suspect list exchange.
2) We developed sun-driven Advanced Oxidation Processes (AOPs) for the efficient removal of CECs. AOPs are based on the generation of hydroxyl radicals, which can oxidize toxic and refractory pollutants yielding their mineralization to CO2 and water. New AOPs and materials, such as ZnO doped with transition metals and lanthanides, dye-sensitized TiO2 or ZnO materials and organic catalysts proved to be very efficient in the removals of CECs. Besides, novel trends in (photo)-Fenton were explored and organic catalysts with reducing properties were developed as well as 2 types of Zero Valent Iron (ZVI) to reduce functional groups recalcitrant to oxidation. A strategy to combine ZVI and photo-Fenton was tested and a reactor for this purpose was designed. As part of waste revalorization and circular economy policies, the use of humic-like substances extracted from olive oil mill wastes was used as auxiliary iron chelating agents to enhance photo-Fenton process.
Photochemical processes have been applied to obtain the contemporaneous disinfection and removal of CECs and the optimization and scale-up of more promising processes was successfully obtained.
3) We integrated the new AOPs with nanofiltration (NF) systems in a unique innovative hybrid tool. A great effort was pursued to explore new fabrication methods for developing NF membranes able to: (i) combine high water fluxes with high retention towards CECs, (ii) be recalcitrant to fouling, and (iii) be easily cleaned.
Five new types of membranes were developed and six different filtration units were assembled to test membranes during development and the hybrid membrane-AOPs technologies. Among the developed membranes, those made of thermocatalytic ceramic–graphene oxide, nanocomposite and surfactant-templated Al2O3-doped silica, and Ce-doped photocatalytic zirconia can achieve nanofiltration performances and therefore they can be used in synergy with AOPs for the simultaneous CECs filtration and abatement. These membranes have outstanding stability in harsh chemical conditions and in acidic pH, which is the requirement for some advanced oxidation processes. We also proved that UF membranes can be used for CECs abatement by adding novel polymers with a dextran main chain and various kinds of cyclodextrins as pendant.
Overall, 85 publications in peer reviewed international journals were gathered, 82 communications and 68 poster communications presented at meetings and congresses.
The presence of new potentially hazardous compounds was assessed in two sampling campaigns performed on natural water and wastewaters sampled in four countries (Italy, France, Greece and Denmark). Untargeted analysis via HR-MS allowed recognizing 649 new CECs identified at level 2 and submitted to the NORMAN Suspect list exchange.
2) We developed sun-driven Advanced Oxidation Processes (AOPs) for the efficient removal of CECs. AOPs are based on the generation of hydroxyl radicals, which can oxidize toxic and refractory pollutants yielding their mineralization to CO2 and water. New AOPs and materials, such as ZnO doped with transition metals and lanthanides, dye-sensitized TiO2 or ZnO materials and organic catalysts proved to be very efficient in the removals of CECs. Besides, novel trends in (photo)-Fenton were explored and organic catalysts with reducing properties were developed as well as 2 types of Zero Valent Iron (ZVI) to reduce functional groups recalcitrant to oxidation. A strategy to combine ZVI and photo-Fenton was tested and a reactor for this purpose was designed. As part of waste revalorization and circular economy policies, the use of humic-like substances extracted from olive oil mill wastes was used as auxiliary iron chelating agents to enhance photo-Fenton process.
Photochemical processes have been applied to obtain the contemporaneous disinfection and removal of CECs and the optimization and scale-up of more promising processes was successfully obtained.
3) We integrated the new AOPs with nanofiltration (NF) systems in a unique innovative hybrid tool. A great effort was pursued to explore new fabrication methods for developing NF membranes able to: (i) combine high water fluxes with high retention towards CECs, (ii) be recalcitrant to fouling, and (iii) be easily cleaned.
Five new types of membranes were developed and six different filtration units were assembled to test membranes during development and the hybrid membrane-AOPs technologies. Among the developed membranes, those made of thermocatalytic ceramic–graphene oxide, nanocomposite and surfactant-templated Al2O3-doped silica, and Ce-doped photocatalytic zirconia can achieve nanofiltration performances and therefore they can be used in synergy with AOPs for the simultaneous CECs filtration and abatement. These membranes have outstanding stability in harsh chemical conditions and in acidic pH, which is the requirement for some advanced oxidation processes. We also proved that UF membranes can be used for CECs abatement by adding novel polymers with a dextran main chain and various kinds of cyclodextrins as pendant.
Overall, 85 publications in peer reviewed international journals were gathered, 82 communications and 68 poster communications presented at meetings and congresses.
The list of hazardous compounds in water bodies is continuously monitored and updated and, because of this, the results achieved by AQUAlity consortium in this topic is surely valuable for society, as it is important to increase the knowledge of the risks related to the presence of these substances so that consequently policy-makers can enact proper regulations about them. The societal awareness on CECs and the protection of the environment was achieved from a wider point of view, through dissemination activities as the participation to 5 editions of the European Researcher Night, preparation of a comic book and videos. Laboratory practices on environment protection were organized and addressed to students aimed to inspire young people to pursue a career in Science.
The structured training-through-research programme of AQUAlity represents a high-quality way to go one step beyond in creating the next generation of integrated Urban Water System management innovators. Green analytical methods and new tracers have been developed and optimized and are now implemented in companies involved in the project to assess water quality. The research activity allowed improvements of actual tertiary treatment plants based on innovative AOP/NF technologies to guarantee access to high quality water for all EU citizens. In particular, two novel ceramic membranes, a tight SiC ultrafiltration membrane and a ZrO2 hybrid membranes reached the highest TRL and entered in the market. Furthermore, innovative materials, often obtained from low-cost sources and prepared following the principles of the green chemistry, were designed, produced, and tested in solar plants with the aim of limiting the energy consumption and to increase the treatment efficiency during a depollution process.
The structured training-through-research programme of AQUAlity represents a high-quality way to go one step beyond in creating the next generation of integrated Urban Water System management innovators. Green analytical methods and new tracers have been developed and optimized and are now implemented in companies involved in the project to assess water quality. The research activity allowed improvements of actual tertiary treatment plants based on innovative AOP/NF technologies to guarantee access to high quality water for all EU citizens. In particular, two novel ceramic membranes, a tight SiC ultrafiltration membrane and a ZrO2 hybrid membranes reached the highest TRL and entered in the market. Furthermore, innovative materials, often obtained from low-cost sources and prepared following the principles of the green chemistry, were designed, produced, and tested in solar plants with the aim of limiting the energy consumption and to increase the treatment efficiency during a depollution process.