Scientists develop system that removes contaminants of emerging concern from wastewater
A team of scientists from the Department of Chemical Engineering (DEQ) of the Faculty of Science and Technology of the University of Coimbra (FCTUC) has developed a reactional solar photocatalysis system, using supported catalysts, capable of removing chemical and biological contaminants from domestic wastewater.
The PhotoSupCatal project, which ends later this month, aims to find a tertiary treatment that can eliminate contaminants of emerging concern to protect ecosystems and try to obtain water that can be reused, for example, for irrigation. In addition to the chemical compounds, the researchers also evaluated the possibility of disinfection, more specifically, they verified the impact of this process on the Escherichia coli bacteria and the results are promising.
«Although domestic wastewater undergoes the usual biological treatments, some polluting chemical compounds that are appearing in the water and that come from human consumption, namely cosmetic and pharmaceutical products, are still not taken into account. These products release molecules into the wastewater that appear in very small concentrations, but which due to their complexity cannot be treated biologically, which is the most common process in municipal wastewater treatment plants», begins by explaining Rui Martins, professor at DEQ and researcher at the Center for Research in Engineering for Chemical Processes and Forest Products (CIEPQPF).
Thus, continues Rui Martins, «The treatment process that we are analyzing is photocatalysis, that is, we have a catalyst that is activated by light, and with this activation, there is the production of radicals, which are very unstable and reactive compounds, which will degrade the organic compounds. As radicals are not very specific, they can theoretically attack all existing organic matter», explains the professor, adding that in this process solar energy will be used as a source of radiation since it has a low cost.
To produce this new system, the FCTUC team developed a sustained catalytic system with supports based on polymers, namely PDMS and polyaniline. «The results show us that these catalysts are able to efficiently degrade the organic contaminants we are testing and that they are stable for various reuse tests. At this stage, we are testing the reactor continuously, at a scale closer to the pilot», he reveals, clarifying that laboratory scale tests have already been carried out with promising results.
According to the DEQ professor, this project will have an impact on the industry, as it will offer a low-cost technology to refine the quality of treated water, allowing its reuse, and on the environment, as it follows the premise of zero pollution, a once these compounds of emerging concern are removed.
«These compounds are persistent in the environment, which means that, despite being discharged in very small amounts, they accumulate and can have an impact on ecosystems and health. This type of technology allows us to remove them before the effluents are released into water courses, protecting them and, in another sense, it will allow us to arrive at the water that is suitable for reuse, for example, in agriculture, which it consumes a lot of water», he concludes.
The project, co-financed by the European Union, through the FEDER, has the participation of nine CIEPQPF researchers and is coordinated by Adventech – Advanced Environmental Technologies, Lda, a company specialized in the development and construction of WWTPs and Gas Emissions Treatment Systems.
Follow us on Facebook, Twitter, Instagram, Youtube, and TikTok and see the exclusive content for social networks.
