1. Combined Ion Exchange as a Pre- and Post-Treatment for High Pressure
Membrane Systems
Jennifer N. Apell Dr. Treavor H. Dr. Katsuki
(M.E., 2009) Boyer Kimura
Flux decline for untreated and pre-treated (9 mL/L
This research was supported by NSF East IRA958, 2 mL/L Amberlite 200, 60 min mixing time)
Asia and Pacific Summer Institutes (ESPSI) Aldrich humic acid (AHA) synthetic water. Filtration
Program award to JNA. continued until 70% recovery was achieved.
Overview and Objectives
As membrane water treatment systems increase in use throughout the world, pre-treatment will be needed to prevent
fouling of membranes and post-treatment of the concentrate will be needed for disposal purposes and to reach zero-
liquid discharge. Dissolved organic matter (DOM) and calcium ions are two major foulants of membrane systems
that cause severe fouling and limit system recovery. Research has begun to address membrane pre-treatment
possibilities but is limited in scope. Little research has been conducted to address the treatment of membrane
concentrate.
Combined anion and cation exchange has been previously shown to effectively remove DOM and calcium from
natural water. The following research questions were formulated based on this previous work. Can combined ion
exchange reduce membrane fouling and allow for higher membrane system recovery? Will combined ion exchange
work for both water and wastewater treatment? Accordingly, the objectives of the proposed research are: (1) to
evaluate combined ion exchange as a pre-treatment for high pressure membrane systems and (2) to use combined
ion exchange to treat the concentrate from high pressure membrane systems in order to increase the recovery of pure
water and come closer to attaining zero liquid discharge.
Conclusions
 The higher average molecular weight of AHA caused a slower exchange rate with the anion exchange
resins and the removal of AHA suffered from size exclusion.
 Calcium exhibited a stronger interaction with SRNOM than AHA causing less removal of calcium in
SRNOM synthetic water than in AHA synthetic water.
 Despite combined ion exchange having similar removals of DOC and calcium for both synthetic waters,
combined ion exchange was able to alleviate a substantial amount of fouling for the AHA synthetic water
and a negligible amount of fouling for the SRNOM synthetic water.
 Further research is needed to discern the characteristics of organic matter responsible for the difference in
the effectiveness of combined ion exchange and membrane fouling.
Apell, J.N., Boyer, T.H., Kimura, K., 2011. “Combined ion exchange (CIX) as a pre-treatment for high-pressure
membrane systems,” Proceedings of the American Water Works Association Membrane Technology Conference,
Long Beach, California, 28–31 March 2011, 6 pp.
Download poster
Treavor H. Boyer, Ph.D. ~ Assistant Professor ~ Department of Environmental Engineering Sciences ~ University of Florida
thboyer@ufl.edu ~ 352.846.3351 ~ www.ees.ufl.edu/homepp/boyer ~ www.twitter.com/WaterWeUpTo