Water Board Aa & Maas starts pilot with a combination of hollow fiber direct nanofiltration and UV technology for the reuse of municipal wastewater

To turn municipal wastewater into a valuable source for high quality process water, Water Board Aa & Maas, NX Filtration, Van Remmen UV Technology and Jotem Watertreatment started a pilot project. The goal is to demonstrate the viability of clean water production from municipal effluent from Aa & Maas’ wastewater treatment plant in Asten, The Netherlands.

This pilot project demonstrates the benefits of the powerful combination of NX Filtration’s hollow fiber direct nanofiltration (dNF) technology, together with Van Remmen’s ultra violet (UV) and hydrogen peroxide (H₂O₂) treatment, to efficiently remove organic micropollutants under optimal circumstances. Although the pilot system directly produces clean water nearing drinkable quality, the water will initially be used as industrial process water and for agricultural purposes in nearby located greenhouses.

The process in this set-up consists of two steps, combining a relatively open version of NX Filtration’s dNF product range with a very effective UV-based post-treatment thereafter. First, dNF80 membranes from NX Filtration remove all color and the vast majority of the micropollutants and organics from the effluent stream, while allowing the useful minerals to pass. The resulting crystal clear water with high transmittance is then treated with optimal efficiency with Van Remmen UV’s Advanox system. Jotem Watertreatment has integrated the containerized pilot in Asten and has also installed a screen to prevent large particles entering the system. And last but certainly not least, the Aa & Maas team facilitated and sped up this pilot project tremendously.

The pilot project will take several months in which not only the quality aspects of the produced water are studied, but also the operating conditions will be assessed. Part of the pilot project is carried out within the framework of the EFRO NanoX-project.

Maarten Nederlof, Senior Advisor Water Board Aa & Maas, comments: “Aa & Maas already has experience with the removal of micropollutants from municipal effluent with traditional technologies such as (powdered) activated carbon and oxidation processes. However, hollow fiber direct nanofiltration in a hybrid setup with UV can facilitate the next step towards producing high quality water for re-use applications, but also towards a solution for the membrane concentrate.”

Joris de Grooth, R&D Manager at NX Filtration, comments: “Our innovative hollow fiber direct nanofiltration membranes enable this simple and sustainable process of reusing wastewater for the production of clean process or drinking water. Compared to traditional methods, we reduce the number of filtration steps as we remove micropollutants (including pharmaceuticals, PFAS and insecticides), color and selective salts, but also nanoplastics, bacteria and viruses from water in one single step. We also avoid the use of chemicals in the pre-treatment of the water. In addition, because our nanofiltration membranes remove all color from the water, the efficiency of the UV treatment is much improved which significantly reduces energy use even more.”