Reuse: Producing ultrapure water from domestic wastewater

Synthetic organic polymer fouling of reverse osmosis membranes

In water treatment synthetic organic polymers play an essential role. Severe irreversible fouling of reverse osmosis (RO) membranes due to these synthetic organic polymers is reported. Unfortunately, these synthetic organic cationic polymers are in many situations the most effective or the only effective polymer type. This situation is a real threat for the further expansion of waste water reuse making use of RO systems and a danger for large (and small) scale sea water / river water desalination based on reverse osmosis and making use of conventional pre-treatment systems (coagulation / sedimentation, flotation, media filtration).

This threat and danger is severe since knowledge on fouling potential, tools monitor and to develop mitigation measures are lacking e.g.,
• Currently is it not known whether all types of synthetic cationic polymers are causing severe irreversible fouling.
• It is not known whether alternative polymers (non-ionic and anionic) are available which are effective but don’t foul RO membranes.
• Analytical methods are not available to measure the concentration of cationic polymers in feed water of RO systems. A complication factor is that these polymers use the have a wide range molecular mass. As a consequence operators have no tool to dose the polymers accurately to avoiding overdosing and/or adapting process conditions.
• Mitigation measures e.g., pre-treatment processes are not developed or not tested and current chemical cleaning methods are not effective in most cases.

Sponsor: NieuWater (Netherlands).
Duration: 2 years, 2012-2014.
Budget: 24k euros.
IHE staff: Jan Schippers, Sergio Salinas, Maria Kennedy
Research fellows: Yuli Ekowati, Madiany Hernandez