13 Okt. Ceramics and UV light lead to clean water
Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS are developing compact foam ceramics with functional coatings that use photocatalytic oxidation to effectively break down even stubborn pollutants in water. “Irradiating the functionalized surfaces with UV light creates highly reactive radicals in the water being treated, which break down organic contaminants,” says Franziska Saft, a scientist at Fraunhofer IKTS in Dresden, explaining the advantages of the development. “This process does not produce any unwanted by-products, nor does it require any additional operating materials such as ozone.”
The efficiency of this process depends heavily on the contact between the pollutant, catalyst, and light. Thanks to their highly porous, network-like structure, foam ceramics offer large surface areas and therefore serve as carriers for various catalysts and adsorbents. In addition, the high open porosity of up to 90% allows for good light transmission. “Our foam ceramics offer a lot of space to anchor various catalysts. This allows us to create a large reaction surface,” says Dr. Daniela Haase, a scientist involved in the project. “High catalytic conversion rates can be achieved even with thin layers on the foam ceramic. It is important though to stabilize the catalysts on the foam so that they are not washed out when the wastewater flows through.”
Plant construction for pilot projects
According to the researchers, this efficient and sustainable solution is intended primarily for treating industrial process and wastewater. The researchers and their interdisciplinary project teams are developing the wastewater treatment plants themselves, from the selection and design of multifunctional foam ceramics with optimized geometry and catalyst coating to the appropriate light sources, such as energy-efficient UV LEDs. The reactor design is also specifically adapted to the respective requirements. This enables integration into existing systems as well as application-oriented scaling and piloting of the plant at the customer’s site. These include companies from the pharmaceutical, semiconductor, paper, dairy, and textile industries that want to break down pollutants directly on site and before they are discharged into the sewage treatment plant. This prevents them from entering the aquatic environment in the first place.
Ceramic stack system with multifunctional foam ceramics and LED array for efficient, photocatalytic purification of industrial process and wastewater. Image: Fraunhofer IKTS
Increased efficiency and scaling
According to the researchers, the results so far are promising. Initial pilot applications show that the photocatalytically active foam ceramic systems successfully break down pollutants. To further increase efficiency, the teams are working on novel catalyst designs and combinations with adsorption materials. In the long term, the researchers aim to establish the technology on an even larger scale and make it a key component of modern industrial water cycles.
Source and image: www.ikts.fraunhofer.de