Nanofiltration of greywater for micropollutant removal

Sam Rutten (PhD Candidate). Erik Roesink (promotor), Joris de Grooth (co-promotor), Lucìa Hernández-Leal (supervisor Wetsus)

Duration: 2019-2023

Funding: Wetsus, European centre of excellence for sustainable water technology, theme: Advanced Water Treatment

Introduction
Separation of wastewater at the source into black water and greywater streams, with the intent of reuse, has gained popularity in the last three decades. The separate collection of black- and greywater has several benefits such as higher concentrations of organics in black water leading to more efficient nutrient recovery and  more efficient water use and reuse. Prior research has shown the reuse potential of greywater, but risks associated with micropollutants, and other emerging contaminants must be considered. Advanced oxidation processes and adsorption to remove these contaminants have been studied extensively in source-separated sanitation plants. However, membrane technologies, like spiral wound nanofiltration, have seen limited implementation, due their high fouling potential and the need for extensive pretreatment. The emerging technology of hollow fiber nanofiltration membranes has the potential to alleviate these drawbacks and will be able to produce a high-quality water stream for reuse and increase the recovery of valuable resources.

Keywords
Membrane technologies, source separated sanitation, micropollutants, nanofiltration, concentrate treatment

Technological challenges
While the new generation of nanofiltration membranes which use polyelectrolyte multilayers as separation layer have shown to be promising method for micropollutant removal, implementation of these membranes in decentralized full-scale applications has not been studied in detail yet.

Research goals
During the project, the integration of a hollow fiber nanofiltration pilot in a full-scale source separated treatment plant will be studied. The goal of this integration is to create a treatment design which will provide permeate of re-use quality while providing an appropriate method to treat the concentrate.