Solutions to overcome technical, legal and economic barriers for the application of NF/RO processes in drinking water treatment

Treatment line of a reverse osmosis system in a waterworks

How should concentrates from NF/UO processes be handled in future? Is treatment of the concentrates reasonable? How can a discharge into a water body be evaluated? Ten project partners focus on these and other questions within the research project KonTriSol.

NF/RO processes are increasingly used for drinking water treatment in Germany. Main applications are water softening or the removal of further inorganic and organic water ingredients, including anthropogenic micropollutants.

Residues from the NF/RO treatment process, so-called concentrates, usually have a high salt content and contain the concentrated organic trace substances, including additives that are applied during the treatment process. Thus, the local authorities increasingly consider the discharge of these concentrates into water bodies as critical.

In order to remove the existing technical and administrative barriers for the implementation of the NF/UO technology in the field of drinking water treatment, the goal of the KonTriSol project is to provide practical solutions and integrated evaluation concepts. The following issues are the main objectives of the project:

- Treatment alternatives to NF/UO processes

- Antiscalants – evaluation and alternatives

- Treatment of concentrates and removal of pollutants from the water cycle

- Assessment of the toxicological relevance for humans and the ecosystem

- Legal and economic barriers and solution strategies

- Evaluation of alternative approaches

-  Development of transfer strategies to selected countries

Within this project, TZW develops an analytical detection method for antiscalants, a lab-scale plant to determine the rejection capacity of NF/RO membranes towards antiscalant agents, and investigates treatment options for the concentrates. Furthermore, the authorisation process for the discharge of concentrates is evaluated and a strategy for concentrate management will be proposed.