Environment, from ENEA new application to purify water from PFAS

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(Finance) – A team of researchers from ENEA Center of Bologna is working on a new application of technology based on a controlled energy electron beam, to remove the PFAS from waters for civil use. The chemical-physical action of the electron beam would allow these pollutants, highly persistent in the environment, to be degraded into substances that are easier to remove and to treat, at the same time, large volumes of water in a very short time.

“In practice, the electron beam breaks the carbon-fluorine bond of the PFAS, which is one of the strongest in organic chemistry. The result is the formation of fluorides, which are still polluting but definitely easier to treat and to break down. Similar technologies are already in use, in various parts of the world, for the treatment of waste water with various types of pollutants and make it possible to significantly reduce the operating costs of the plants. In the case of PFAS, this technique may be the only one that is really effective for obtaining satisfactory results, ”he explains Antonietta Rizzohead of the ENEA Laboratory “Nuclear Methods and Techniques for Safety, Monitoring and Traceability”, which is part of the Emilia-Romagna High Technology network

The PFAS are a lot widespread: They are used, for example, in waterproof and stain-resistant clothing, in fire-resistant foams and fire-retardant fabrics, in non-stick coatings of pots and pans, in packaging such as microwave popcorn bags and in numerous fast-food food wrappers , in cosmetics, furnishing fabrics, paints, chrome plating, films that cover solar panels but also in building materials such as coatings for metals and tiles. In the OECD database they are listed below 4,700 types of PFAS molecules and they all have an extremely high persistence in common.

“These chemicals are highly soluble in water and do not degrade in the environment due to their chemical stability, contaminating drinking water, food and feed wherever they are used. Even if we stopped producing them immediately, they would remain in circulation for generations, considering that no other artificial chemical substance remains in the environment as long as PFAS, with an important impact on surface and deep aquifers “, adds the researcher of the same ENEA laboratory. , Clear Telloli.

So far, the methodologies from purification traditional based on ion exchange resins or on activated carbon. In addition to being expensive, they often produce waste that is itself special waste, to be treated later in suitable plants with a further increase in costs and an inevitable environmental impact. “Hence the need to study alternative technologies to be transferred to the national industry. An Italian company specializing in water purification, the Tintess of Thiene (Vicenza), has already shown interest in this innovation and is evaluating any developments in the technological feasibility and sustainability of the process “, underlines the researcher of the same ENEA laboratory, Alberto Ubaldini.

In detail, the ENEA team intends to treat the water contaminated by PFAS with plasma electronica technology that – using only electricity – converts water into one blend of highly reactive chemical species, which perform a rapid degradation action of multiple pollutants, including the PFAS themselves. Not only that, they allow you to treat a large volume of liquids in a limited time or possibly even continuously.

“THE benefits they don’t end there. These chemical species produced from the electron beam are very ‘aggressive’ but short-lived, of the order of a few milliseconds, and do not introduce any possibility of contamination since, at the end of the process, they cannot survive in the plant. This means none radiation residual remains in the irradiated water after the treatment. The only real practical limitation is the limited penetration of electrons into the water which is a few centimeters. But a study is underway on this aspect to evaluate thepenetration efficiency and the thickness of water negotiable”, Explains Antonietta Rizzo.

Generating a bundle of electrons with high voltage (or electron beam) it is very advantageous and converts the input power into beam power with efficiencies up to 95% (compared to the 30% obtained in UV lamps). In this way, the operating costs of the purification plants and the residues chemists, still present after the process, could be easily eliminated by well-established technologies, such as precipitation or coagulation which use simple chemical reagents added at the end of the process. “The Laboratory recently followed a degree thesis in engineering energyin which theoretical assessments of investment costs were made, equal to approximately 14 million euros, and it was found that there is an important economy of scale for this type of plant ”, concludes Rizzo.

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