Water treatment

Description
In many areas, drinking water needs to be cleaned of various pollutants by means of filtration through porous membranes. Nanofiltration removes particles and micropollutants down to approx. 250 Da or dissolved salts according to the membrane charge.

However, reversed osmosis membranes are used to remove substances dissolved in water (salts, hormones, pesticides, antibiotics, PFAS). For drinking water purposes, salts must be re-added to the obtained salt-free water.

To overcome the osmotic pressure, very high pressures and high energy consumption are required during filtration.

Together with various companies, we have developed an overcoating of the 20 nm pores with only 16 nm thin LbL layers of low pore width and high charge, with which 60 - 95% of the above-mentioned pollutants are retained and fouling is reduced.

As monovalent salt ions pass through the LbL layer, there is hardly any osmotic back pressure, so that the membranes can be operated at low pressures to save energy.

Partner

• X-Flow BV (brand of Pentair), Enschede, Netherlands
• inge GmbH (brand of DuPont), Greifenberg, Germany
• Nanostone Water GmbH, Halberstadt, Germany

Reference

• Daniel Menne, Cagri Üzüm, Arne Koppelmann, John Erik Wong, Chiel van Foeken, Fokko Borre, Lars Dähne, Timo Laakso, Arto Pihlajamäki, Matthias Wessling “Regenerable polymer/ceramic hybrid nanofiltration membrane based on polyelectrolyte assembly by layer-by-layer technique” Journal of Membrane Science (2016) 520, 924–932.
• Danijela Gregurec, Mateusz Olszyna, Nikolaos Politakos, LuisYate, Lars Dähne; Sergio Enrique Moya “Stability of polyelectrolyte multilayers in oxidizing media: a critical issue for the development of multilayer based membranes for nanofiltration” Colloid Polym Sci (2015) 293: 381–388.
• Robert Niestroj-Pahl, Lara Stelmaszyk, Ibrahim M. A. ElSherbiny, Hussein Abuelgasim, Michaela Krug, Christian Staaks, Greta Birkholz, Harald Horn, Tian Li, Bingzhi Dong , Lars Dähne, Andreas Tiehm and Stefan Panglisch: "Performance of Layer-by-Layer-Modified Multibore® Ultrafiltration Capillary Membranes for Salt Retention and Removal of Antibiotic Resistance Genes"” Membranes (2020) 10, 398 https://doi.org/10.3390/membranes10120398

SIGN-2

Sino-German water supply Network – Clean water from the source to the tap. Removal of hardly degradable dissolved substances from drinking water through coated ceramic hybrid membranes.

Partner:

• K3S Antriebe GmbH, Berlin
• 3S Consult GmbH, Dresden
• bbe Moldaenke GmbH, Schwentinental
• Ingenieurgesellschaft F.A.S.T. GmbH, Langenbrettach
• Forschungszentrum Jülich GmbH, Jülich
• Hydroisotop GmbH, Schweitenkirchen
• inge GmbH, Greifenberg
• IWW gGmbH, Mülheim
• Karlsruher Institut für Technologie (KIT)
• Postnova Analytics GmbH, Landsberg am Lech
• Rheinisch-Westfälische Technische Hochschule Aachen (RWTH)
• Tongji University, Shanghai
• Chinese Research Academy of Environmental Sciences (CRAES), Beijing
• Hua Yan Water, Suzhou
• Suzhou Water, Suzhou
• Jiangnan University, Wuxi
• Nanjing Institute of Geography and Limnology (NIGLAS), Nanjing
• Suzhou University of Science and Technology, Suzhou

funding agencies: DVGW-Technologiezentrum Wasser Karlsruhe (BMBF: 02 WCL 1471L)

www.water-sign.de

Project duration: 01.09.2018 - 31.08.2021

Reference

• J. Stumme, O. Ashokkumar, S. Dillmann, R. Niestroj-Pahl, M. Ernst, Theoretical Evaluation of Polyelectrolyte Layering during Layer-by-Layer Coating of Ultrafiltration Hollow Fiber Membranes, Membranes 11 (2021) 106. https://doi.org/10.3390/membranes11020106
• J. Radeva, A.G. Roth, C. Göbbert, R. Niestroj-Pahl, L. Dähne, A. Wolfram, J. Wiese, Hybrid Ceramic Membranes for the Removal of Pharmaceuticals from Aqueous Solutions, Membranes 11 (2021) 280. https://doi.org/10.3390/membranes11040280
• M. Vergara-Araya, H. Oeltze, J. Radeva, A.G. Roth, C. Göbbert, R. Niestroj-Pahl, L. Dähne, J. Wiese, Operation of Hybrid Membranes for the Removal of Pharmaceuticals and Pollutants from Water and Wastewater, Membranes 12 (2022) 502. https://doi.org/10.3390/membranes12050502

Layer-by-layer coated ceramic membranes for the resource-efficient production of drinking and process water - KeraRes

Description
In the KeraRes project, together with the company Inflotec and other partners, decentralized water treatment plants are being developed that either quickly provide drinking water from contaminated water in the event of a disaster or treat heavily contaminated water from industry and agriculture to such an extent that it can be reused in the cycle.

For this purpose, high-quality ceramic membranes from Nanostone are coated with nanometer-thin functional layers that are individually adapted depending on the type of contamination. The technology is scalable and also reduces fouling of the membranes.

Partner:

• Inflotec GmbH, Wolmirstedt, Germany
• DVGW-Forschungsstelle TUHH, Hamburg, Germany
• Wehrwissenschaftliches Institut für Schutztechnologien, WIS GF Wasseraufbereitung, Munster, Germany
• Umweltbundesamt, Berlin, Germany

Reference

• R. Niestroj-Pahl, E. Te Brinke, H. Roth, L. Dähne, W.M. De Vos, Symmetric and asymmetric ceramic-supported polyelectrolyte multilayer nanofiltration membranes, Journal of Membrane Science 713 (2025) 123366. https://doi.org/10.1016/j.memsci.2024.123366
• R. Niestroj-Pahl, A. Domaç, I. Achterhuis, L. Dähne, W. M. de Vos, H. Roth, Asymmetric PMAA- or PAA-based polyelectrolyte multilayer membranes: The role of polyanion structure on separation properties, Journal of Membrane Science (2025) (submitted)