PROPOSAL NUMBER 00-1 10.01-9417 (Chron: 000584 )
Sub-Micron Particle Removal From Gas-Water Mixtures Without Flow Restrictions

The removal of sub-micron sized particles from an aqueous stream based on electrostatic
attraction is proposed. The system will remove suspended particles from a gas-water-
solid mixture with minimal flow restrictions. This is particularly important for the
removal of fine alumina particles in the outlet stream from the Volatile Removal
Assembly (VRA), since high pressures are required to force the gas-water mixture
through a small pore collection filter. Electrophoretic particle removal will result in
direct capture on the oppositely charged surface of removal media or an electrode, or by
collection of larger aggregates formed at such surfaces on a large pore filter. Zeta
potential is a measure of the effective surface charge on suspended particles. For oxides,
the zeta potential varies strongly with pH, reaching zero at the isoelectric pH. The zeta
potential is negative at pHs above this value, and positive at pHs below it. Particle
collection by removal media requires an opposite polarity zeta potential, or alternatively,
an electrode with the proper surface potential at the pH of interest. The Phase I effort will
demonstrate feasibility. The Phase II project will result in the delivery of a prototype
scaled to handle the nominal VRA flow rates.

It is anticipated that a particle removal system based on the electrostatic interaction of
very fine particles in water with removal media will have numerous commercial
applications. Foremost among these will be as Flight Hardware purchased by NASA, or
by an aerospace contracting firm on behalf of NASA, to provide enhanced capability in
support of the water processor aboard the International Space Station (ISS). Terrestrial
applications include replacement of conventional filtration techniques for particulate
control in water systems. The removal of extremely fine particles without large pressure
drops associated with fine filtration is a leading candidate. High value products that are
susceptible to adsorption on conventional filter elements are another area of potential
application. Many commercial processes require the addition of flocculating agents to
remove products or wastes from the process stream. Extensive washing of flocked
aggregates is required to complete the process, adding expense and time to the overall
process. The utilization of electrostatic flocculation methods can greatly simplify this
requirement and improve profitability. It is anticipated that as a result of the Phase II
effort, UMPQUA Research Company (URC) will develop a technology demonstrator to
help market this process.

NAME AND ADDRESS OF PRINCIPAL INVESTIGATOR (Name, Organization Name, Mail Address, City/State/Zip)
James R. Akse, Ph.D.
Umpqua Research Company
PO Box 609
Myrtle Creek , OR   97457 - 0102

NAME AND ADDRESS OF OFFEROR (Firm Name, Mail Address, City/State/Zip)
Umpqua Research Company
PO Box 609
Myrtle Creek , OR   97457 - 0102