TU Dresden tests pioneering technology at the "Blockhaus" waterworks in Liebenau
Nienburg/Liebenau. The Technical University of Dresden is developing a water desalination process under the leadership of Professor Dr André Lerch. The speciality: In contrast to "classic" desalination plants, only the ions that need to be removed are retained in an electrochemical process. The potential of the technology is estimated to be correspondingly high. One of the TU's partners is the District Association for Water Management.
The Kreisverband für Wasserwirtschaft and TU Dresden have already carried out a number of projects together in the past, for example on energy optimisation in the field of municipal water supply. "Research and practice work well together in our case," emphasises Joachim Oltmann, Head of the Drinking Water Supply Department at the district association. "We are delighted to be able to support the TU again this time."
When the term "desalination" is mentioned, the layman primarily thinks of seawater desalination plants, such as those used in Saudi Arabia. But that is not the point, emphasised project manager Professor Dr.-Ing. Lerch on site at the "Blockhaus" waterworks: "In the known processes, all salts are first removed. Afterwards, they have to be added back in parts with some effort so that the water remains usable or drinkable. In contrast, the core of our process is to change the composition of the water as little as possible. We only remove the salts that need to be removed in different application scenarios."
While nitrates from agriculture are removed from the water at the "Blockhaus" waterworks, a second pilot plant on Langeoog deals with sodium and chloride, which enter the island's groundwater via the seawater. Targeted transport is possible using specially adapted membranes.
The new technology could solve many problems, but is not available for free: Hanna Rosentreter, research assistant at the Faculty of Environmental Sciences at TU Dresden, estimates the energy requirement at around 0.1 kilowatt hours per cubic metre of water to be treated. However, it is not a question of operating a plant on a large industrial scale at the Liebenau waterworks: "The water here is fine," emphasises Rosentreter. "Specialised desalination is not necessary."
Water expert Joachim Oltmann agrees: "Quite apart from our technical facilities for water treatment, we have been committed to groundwater protection together with the agricultural sector for many years." The system running in the "Blockhaus" is merely intended to confirm in practice what has worked well in the laboratory so far. According to Hanna Rosentreter, the pilot project, which will run until August, will provide a basis for making concrete statements about the performance and costs of a large-scale industrial plant that could be used in areas where the salt load in drinking water is too high.
"For us water suppliers," Joachim Oltmann summarises the on-site visit, "it's about expanding our options for action. We don't know what the future holds and how the salt loads in drinking water will develop as a result of climate change. So it's good to have a practical solution up our sleeve."
DIE HARKE (DH)
