The team led by Dr. Ann-Kathrin Kniggendorf and Prof. Bernhard Roth, a member of the Cluster of Excellence PhoenixD at Leibniz University Hannover, received the award for their research on detecting microplastics in water using optical technologies. Unfortunately, the award was presented one year late at the 4th OptecNet Annual Conference at Expowal in Hannover due to the pandemic. The two-day conference brings together the key players from industry and science who are involved in optics and photonics research in Germany and are responsible for transferring knowledge into practice.
The prize, which is endowed with 15,000 euros, is awarded every two years by the Goslar-based Stöbich Group to German scientists from research or industry on a special focus topic in the field of optical technologies. This year, the prize was awarded for pioneering new developments for environmental and climate protection. In addition to scientific excellence, the submitted work should also demonstrate the possibility of practical, industrial implementation.
In its research, the HOT team addresses a major social challenge: detecting plastic waste in the environment. In particular, it is concerned with microplastics, i.e. plastic particles that are smaller than five millimetres and are introduced into the environment via various pathways, for example, as ingredients of cosmetics, through car tires'' abrasion by-products in production or decomposition processes. They also get into food and drinking water and can be absorbed into the organism via the food chain. Since they can be hazardous to health, effective methods of detection and elimination are needed.
"Our team''s newly developed method makes it possible to monitor microplastics in the drinking water stream in real-time and without filters or sampling," says Roth. He says this is a real innovation in the field, as such examinations can currently only be carried out using expensive analytical methods in the laboratory. If the analyses of the probes are not conducted under controlled laboratory conditions, subsequent contamination with microplastics from the air is unavoidable. This, in turn, can be a significant source of error, especially in examining drinking water. In addition, monitoring the flow of drinking water, which would be necessary to detect contamination of drinking water with microplastics in real-time, is currently not possible, says Roth.
The award-winning system, on the other hand, is mobile and uses laser light to examine samples. In addition, the new system allows water contamination to be accurately determined with a response time of milliseconds, enabling users to react quickly to contamination and, for example, stop the supply of drinking water for general supply or beverage production.
"OPTIMUS" is the name of the award-winning project, which was funded by the German Federal Ministry of Education and Research. The system works with purely optical measurement methods," says Dr. Ann-Kathrin Kniggendorf, group leader at HOT in the area of environmental analytics. "In operation, therefore, there are no further costs apart from the cleaning and operating current required everywhere."
The water flowing through the measuring line is continuously monitored by a laser barrier. A camera also counts all particles, while a spectrometer detects the specific "fingerprint." The size and shape of the microplastic can also be determined, even in heavily contaminated water samples from wastewater treatment plants. By collecting the particles, the cause and, if necessary, the polluter of contamination can be traced.
In the future, such optical systems could be realized using modern, additive manufacturing methods. Roth is also pursuing these goals in the Cluster of Excellence PhoenixD, developing new methods for manufacturing complex optics. In this context, the digitalization and miniaturization of the systems, the scaling of manufacturing, and automated, intelligent data evaluation are crucial for spreading the process. In addition, the industrial partners are currently preparing for the commercialization of the system.
An online presentation of the research project OPTIMUS can be found here.
The official press release of Leibniz University Hannover is available here.