Catalan Water Research Institute research and innovation for the sustainable use of water

ICRA patents new technology with graphene sponges that removes persistent pollutants from water cheaply and without chemicals

Tuesday, 07 June 2022

The development of nanostructured graphene sponge electrodes for water treatment is the new technology patented by the team of researchers from the Catalan Water Research Institute (ICRA) , which does not use chemicals and is between 60 and 120 times cheaper than other electrochemical processes. These nanotechnological elements allow, for the first time, an electrochemical treatment of persistent water pollutants without producing toxic compounds from chloride oxidation, which is the main limitation of existing electrode materials.

The research is part of the European project Electron4water who leads Jelena Radjenović, ICREA research professor at ICRA, who will be awarded today, Tuesday, June 7, with the 2021 National Young Talent Research Award, awarded by the Government of the Generalitat and the Catalan Foundation for Research and Innovation (FCRI) .

One of the main concerns worldwide is the security of the water supply due to climate change and the presence of highly toxic and persistent substances such as perfluoroalkylated compounds (PFAS) in aquatic environments. “In the search for new technologies to remove PFAS and other emerging pollutants, electrochemical processes offer many advantages over other advanced oxidation processes. It uses only current without adding chemical reagents and at the same time has the ability to treat water of any origin, from tap water to industrial effluents, or the fact of breaking carbon-fluorine bonds, CF, one of the bonds stronger chemicals, overcoming one of the biggest obstacles presented in advanced oxidation processes” – he explains Jelena Radjenović . However, the mass application of these processes has been limited, in part, by the high cost of the electrodes, which ranges from €3,000 to €6,000 per m2 and by the generation of highly toxic chlorinated by-products due to the oxidation of chloride during treatment, an ion found in all waters.

These limitations disappear with the advances made by the ICRA team. The developed graphene sponges offer remarkable advantages over the materials currently used in commercial electrodes. The production cost of this material is much lower: less than €50 per m 2 , which makes it highly attractive for large-scale application. In addition, the synthesis process is easily scalable and allows the functionalization of the sponge to attract and degrade certain groups of organic pollutants, thus increasing the efficiency of the process in complex matrices.

For Jelena Radjenović , “The new electrochemical systems are the great revolution in water management and treatment (which they also call water 4.0). It is a big step towards the implementation of decentralized water treatments instead of the current system that has prevailed for 100 years. In the future, for example, we will have water treatment and reuse directly in buildings or company estates, instead of only having the residual and potable water system of the WWTPs or ETAPs. And it will be able to adapt to population growth or cover more remote areas.”

In this sense, Jelena insisted on recalling the advantages of the electrochemical system: “They work only with current and can even be connected to solar panels easily. They do not require the addition of chemical reagents and there are no production, storage, transport and handling costs, they are small in size (they have a modular design) and can be easily automated”.

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