Resource and energy efficient water treatment by innovative dielectrophoresis membranes
The scarcity of drinking water is worsening due to the increasing demand for water and the decreasing availability of pure water sources. One possible source is the extraction of groundwater, which must be treated before it can be used as drinking or irrigation water. In this context, technologies based on filter membranes are mainly used. However, a major limitation of these processes is the deposition of the substances or particles to be separated on the membrane surface. In continuous operation, these impurities cause a continuous reduction of the water flow through the membrane.
The aim of the REMEMBER project is therefore to develop a new type of dielectrophoresis (DEP) membrane to reduce deposition effects during the filtration process. For this purpose polymeric membrane surfaces are to be provided with thin conductive strips and electrodes by means of printing processes, and subsequently provided with a titanium oxide coating as a protective layer and dielectric by means of an innovative process. In order to improve membrane lifetime of the functionalized membrane, a local treatment of the functionalized membrane surface is to be carried out by means of a laser. All processes are to be applicable inline under atmospheric pressure in order to be able to produce cost-efficient filters with increased efficiency and service life.
Focus of the work:
- Design of electrode geometries and adaptation to specific applications
- Generation of metallic electrodes on filter membranes by printing of particulate, metallic pastes by screen printing
- Development of a coating process based on an atmospheric (plasma-supported) vapour deposition process for the production of TiO2 layers
- Suitability of a UV laser treatment for local microstructuring of coated electrodes, compaction/ densification of the coating and decoating/ stripping on the membrane surface
- Membrane test with regard to the fields of application and geometry of the filter modules
- Determination of voltage and frequency ranges for an optimal operating point
- Practical tests of filter modules and systems for the purification of surface water and groundwater
12/2019: Results and perspectives for practice