Characterization of Reverse Osmosis Membrane Foulants in Seawater DesalinationEPA Grant Number: F6A20646
Title: Characterization of Reverse Osmosis Membrane Foulants in Seawater Desalination
Investigators: Ladner, David A.
Institution: University of Illinois at Urbana-Champaign
EPA Project Officer: Lee, Sonja
Project Period: September 1, 2006 through September 1, 2009
Project Amount: $111,000
RFA: STAR Graduate Fellowships (2006) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Engineering and Environmental Chemistry , Fellowship - Environmental Engineering
Drinking water supplies are diminishing in the United States due to increasing demands from agriculture, more stringent potable use regulations, and extended droughts. Several municipalities are now investigating the feasibility of obtaining drinking water from seawater. If this “new” water source can be tapped efficiently, the burden on rivers and aquifers will be lessened, potentially improving their quality. Desalination certainly will not be the ultimate solution to all of our nation’s water needs, but it will be an additional source from which we can draw as our society seeks water resource sustainability. The objective of this dissertation research is to improve one of the most widely-used desalination technologies, reverse osmosis (RO). The work focuses on a principle limitation inherent in RO, membrane fouling.
The project builds on previous bench-scale work where different size fractions of seawater foulants caused varying levels of RO fouling. Seawater will be fractionated into size classes using microfiltration and ultrafiltration membranes before fouling tests run on a bench-scale RO unit. To detect inorganics and organic functional groups in the fouling layer, fouled membranes will be analyzed with scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX) and attenuated total reflectance, Fourier transform infrared spectrometry (ATR-FTIR). Foulants will be further characterized using high performance size-exclusion chromatography (HPSEC) to determine the size distribution and makeup of organic constituents. Pyrolysis gas chromatography-mass spectrometry (pyrolysis GC/MS) and nuclear magnetic resonance (NMR) will be applied to a few representative samples to further characterize the organic foulant makeup.
The main hypothesis of this work is that future development of antifouling membranes and fouling control strategies will be greatly aided by a better understanding of the nature of organic foulants in seawater.