Adsorption for reverse osmosis concentrate treatment

jurgen roman (UT)

PhD project

Supervisors: Walter van der Meer (UT, promotor), Jeffery Wood (UT), Antoine Kemperman (UT)

Duration: 2021-2025

Funded by Oasen N.V.

Introduction
Reverse osmosis is a water treatment/desalination technique that is known for producing very clean water streams. The downside of this technique is that almost all the pollutants end up in the retentate stream, meaning that a large waste stream is produced. A portion of these pollutants (generally called micropollutants) is not addressed in many current wastewater or drinking water treatment processes and are therefore persistent in water resources. Many of these micropollutants, for example many medicines, stem from industrial- or municipal water discharge. In order for the reverse osmosis process to be more sustainable, removal of these micropollutants from the discharge needs to be integrated into the process. If cleaning up of the concentrate discharge can be achieved, the reverse osmosis process could be an even more valuable option for both water treatment and cleanup of industrial discharge.

Keywords
Reverse osmosis, adsorption, micropollutants, semi-batch processes

Research goals
In this research we focus on treating reverse osmosis retentate streams by making use of the fact that otherwise difficult to remove dilute pollutants are more concentrated in the retentate stream. The approach will be to combine a reverse osmosis and adsorption process step to prevent these micropollutants from entering water resources. The higher concentration of pollutants in the adsorption bed is thought to lead to easier adsorption and therefore more pollutant removal. By operating both the reverse osmosis and adsorption process simultaneously, we intend to get insight into the relevance of operating parameters, the interaction of the processes and possible improvement of adsorbent capacity in operation.