Technical
Paper
Catalytic Hydrogen Deoxygenation and Triple
Membrane Demineralization at North Anna
Nuclear Station
Authors: Preston Sloane, Virginia Electric Power
and Brian P. Hernon, Ionics, Inc.
This paper was originally presented at the 51st Annual International Water Conference, October
1990, Pittsburgh, Pennsylvania. Reprinted with the
permission of the Engineers’ Society of Western
Pennsylvania.
Description of System
The system flow sheet is shown in Figure 1. Raw
lake water is obtained at the plant’s cooling water
intake. The water is pumped through a 200-300
mesh screen and fed to the pretreatment trailer at
approximately 80-100 psi.
Note: GE Water & Process Technologies purchased
Ionics in 2005.
Background
The North Anna Power Station (NAPS) of Virginia
Power Company (Virginia Power) is a two unit plant,
each unit is rated at 980 megawatts and each utilizes a Westinghouse pressurized water reactor.
The plant is located in Mineral, Virginia and sits on
the shore of Lake Anna. This lake is man made and
was specifically built to provide cooling and
makeup water to the power station. The quality of
the lake water and past experiences treating this
water have been the subjects of two previous papers at this conference.1,2
In the spring of 1989 Virginia Power sought bids
from various vendors to supply this station with a
vendor owned and operated 360-gpm (1.4 m3/h)
high purity makeup water system. On May 31, 1989
a five-year contract was awarded to Ionics to provide a system starting September 1, 1989. The system consists of a pretreatment trailer, three 120gpm (0.5 m3/h) triple-membrane trailers, a
hydrogen fed catalytic deoxygenation trailer and
an ion exchange trailer utilizing portable ion
exchange bottles. The system began operation on
August 31, 1989 and has been producing highquality water since.
Figure 1: North Anna Power Station Process
Flow Diagram
In the pretreatment trailer the feed is split into
three separate lines each of which feeds a 54-inch
(1.4-meter) multimedia filter. The filters contain five
layers of media including a gravel support layer,
two layers of different size garnet, a layer of sand
and a top layer of anthracite. The filters are semiautomatic and require manual initiation of the
backwashing procedures. Chlorine of 0.3-0.5 ppm
is fed directly upstream of each filter. The product
from each of the filters is kept separate and is fed
directly to one of the three triple-membrane
trailers (TMTs).
The TMTs are the heart of the water treatment system. These trailers utilize the three membrane
processes of ultrafiltration (UF), electrodialysis
reversal (EDR) and reverse osmosis (RO) in series to
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TP1070EN.doc Mar-10
produce a high quality product water on a consistent, reliable basis, regardless of feedwater conditions (see flow sheet Figure 2)3,4,5 Each of the three
TMTs in this system is an identical, factory built and
tested, 120-gpm unit which operates independently.
in several published reports.6,7,8,9,10 The design of
the EDR units used in these trailers differ only in the
use of the RO reject stream as a makeup stream to
the EDR brine stream. This stream, the “brine
makeup stream,” normally is fed with, EDR feedwater, which in the TMT would be UF permeate water.
In this case, however, the RO reject stream, which
is lower in TDS than the UF permeate stream, is
used as the brine makeup stream. This feature,
which is used on all TMTs, allows the TMT to run at
a high overall water recovery rate, and also
reduces the load on both the ultrafiltration and
multimedia filtration systems.
Figure 2: Triple Membrane Trailer Flow Sheet
Product water from the EDR is sent into the RO
feed tank. In the RO system advanced thin film
composite membranes are used to obtain maximum rejection of salts, organics and silica. These
types of membranes are not chlorine tolerant. Due
to this, sodium bisulfite is injected in the EDR product line upstream from the RO tank to remove any
residual chlorine in the water. In addition, caustic is
added to this stream to elevate the pH. The purpose of this is to convert carbon dioxide, which
would pass through the RO membrane, into bicarbonate, which is rejected by the RO membranes.
The water entering the TMTs first flows into the
ultrafiltration system. The water flows to the UF
feed pump where it is boosted in pressure and fed
into the UF vessels. There are 14 vessels in the system arranged in a parallel, single pass design. Each
vessel contains four, 8" x 40" (0.2 x 1.02 meter) spiral wound, polysulfone membranes with a nominal
molecular weight cutoff of 50,000. The membranes
used have a nominal filter rating of 0.012 microns
and will reject bacteria and high molecular weight
organics. Being of polysulfone construction the
membrane has excellent chemical stability and is
immune to bacterial attack. It also is tolerant of
chlorine, which allows the feedwater to be chlorinated, an important consideration with a raw lake
water feed source.
The bulk of the reject stream in the UF is recycled
back to the suction of the UF feed pump. This is
done to maintain adequate flow rates in the reject
stream, to maintain a low element recovery rate
and to allow high overall UF recovery rates. A portion of the reject stream is not recycled and is sent
to waste. The permeate from the UF is sent into the
EDR feed tank.
In the EDR system the incoming water is desalted
using small amounts of electrical power. In this
case 90% salt removal is achieved in the EDR
stacks using approximately 0.1 Kw-hr/1,000 gallons of DC power. In addition a large amount of
organic matter is removed from the feedwater. The
membranes used in the EDR have excellent chemical and physical stability and are also chlorine tolerant.4 The EDR system is capable of handling
variable feed TDS levels and temperatures.6
The EDR units used in this system are standard EDR
units modified for trailer use. The EDR unit
design and operation has been discussed in detail
Page 2
From the feed tank water flows to the RO highpressure pump where it is sent into the RO pressure vessels. This system contains eight, sixelement vessels, which are arranged in two banks.
The number of vessels on line and the array configuration is adjusted for seasonal temperature
changes. During the summer, the RO is run with a
3/1 array, whereas in winter the unit is run as a 4/2
array. The unit is provided with extra tubes to allow
operation as a 6/2 array in the case of severe fouling of the RO membranes.
The reject water of the RO system is fed back to the
EDR unit where it is used as the brine makeup
stream as described above. The product water of
the RO system is sent out of the TMT and into the
ion exchange trailer.
In the ion exchange trailer the RO product from
each of the TMTs arrives in a separate line and is
fed into a separate primary bank of ion exchange
bottles. Each bank of bottles consists of eight portable 3.6 cubic foot mixed-bed ion exchange bottles
in parallel. These bottles are regenerated at an offsite facility under highly controlled conditions. This
facility uses semiconductor grade water in all its
regeneration procedures and documents silica,
TOC and resistivity levels on each ion exchange
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bottle. In this step any remaining ionic constituents
are removed from the water and additional TOC
reduction is achieved.
The product water from each of the primary banks
of ion exchange bottles is filtered (five micron) and
is combined in one line and sent into the catalytic
oxygen removal system (CORS) trailer. In the CORS
unit deoxygenation of the water stream takes
place. The CORS unit is described elsewhere in this
paper in greater detail.
The product water of the CORS unit is sent back
into the IE trailer to be treated in a final polish ion
exchange step. In this step the water is directed to
one of three banks of portable, polish mixed-bed
bottles. Each bank has eight bottles arranged in
parallel as described for the primary banks. The ion
exchange bottles in this step will remove any CO2
and other impurities that may have entered the
flow stream in the CORS trailer. Proper flow rates
through the banks are maintained using motor
operated valves that will operate based on the
number of TMTs producing water.
The effluent from each of the polish banks is filtered (five micron). The filtered effluent of the three
banks is then combined into one stream. This
stream is monitored, using on-line instrumentation,
for TOC (Anatel-Model A100), silica (Hach-Model
5000), sodium (Orion-Model 1811LL) and resistivity.
If any of the parameters are out of specification
(see Table 1) the effluent water can be and is
directed to waste.
Assuming the water is within specification the
effluent stream is sent out of the IE trailer and into
a Virginia Power 100,000 gallon (379 m3) storage tank.
Water is drawn from this tank for power station needs.
The entire water treatment system, including the
CORS unit operates automatically. Level switches
on the VEPCO storage tank start and stop the system that runs unattended over 50% of the time.
Instrumentation in the system will shutdown the
system or a portion of it in the case of a component failure or abnormal operation. When a shutdown occurs an automated alarm system
summons an operator on call to the site so that
appropriate action may be taken. In the case of
water being out of specification as measured by
one of the on-line instruments, product water is
diverted to waste to prevent contamination of Virginia Power’s storage tank.
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Table 1: Average Analysis of North Anna Feedwater
and Final Product Water
Parameter
TOC (ppb)
North Anna
Raw Water
GE Effluent
3,800
20
100
Specification
Conductivity
(µS)
55
0.06
0.1
Sodium (ppb)
4,500
0.3
1
9,000
<5
10
8,000
5
100
Reactive Silica
(ppb as SiO2)
Oxygen (ppb)
Results
Multimedia Filters
Since raw, untreated lake water is the feed source
for this system multimedia filters are used as a
roughing filtration step prior to the TMT units. In
this capacity the filters are expected to reduce the
load of foulants passing into the UF units.
The multimedia filters were initially operated with
various cationic polymers being injected immediately upstream of the filters to enhance filter performance. Polymer dosage was optimized on filter
effluent turbidity levels. Effluent turbidities were
maintained at less than one NTU with feedwater
NTUs ranging from 2-4 NTUs.
After a few months of operation, coinciding with
the seasonal reduction of feedwater temperature
from 70°F to 40°F (21°C to 4°C), “mud ball” formation, causing channeling and inefficient filtration
was found in the media beds. Heavy bacterial
growth was also found in the media bed (no chlorine was initially injected into the system). This
growth was enhanced with polymer addition.
These factors in turn increased the rate of fouling
in the ultrafiltration systems in the TMTs. The main
cause was determined to be the polymers used in
the multimedia filters. Apparently coagulation was
occurring in the ultrafiltration membranes.
By eliminating polymer dosing and by injecting
chlorine into the feed stream of the filters the
above problems were resolved. Since these steps
were taken (December, 1989) there has been no
evidence of “mud ball” formation and the rate of
fouling of the ultrafiltration units has significantly
decreased. Effluent turbidities have been slightly
higher since polymer dosing was stopped but this
has not been shown to affect ultrafiltration performance.
Page 3
Triple Membrane Trailer
The three membrane systems in the TMT process
are complimentary and sometimes redundant
processes whose individual performance can be
measured in various ways. The goal of the total
TMT system being to maintain a consistent, reliable
high-quality RO product water for further processing in the IE and CORS trailers.
The ultrafiltration unit performance can best be
measured in terms of permeate SDI levels. Figure 3
shows a consistent and stable SDI reading in the
UF permeate since startup. This means that the UF
has been properly removing solids from the system
and protecting the EDR and RO units downstream
in the trailer. Cleaning of the UF unit was initially a
concern as noted above. Since changes were
made in the pretreatment system, cleaning has
been reduced to a bi-weekly maintenance procedure. Cleanings are performed using a
hydrogen peroxide solution at an elevated pH. This
solution is effective in removing organic matter
that is the primary foulant of the UF membranes.
rejection. TOC reduction across the RO units has
averaged 97.0%. Average silica rejection has been
98.7%. Salt rejection has been consistently high
with an average RO product conductivity of
approximately 1.0 microsiemens/cm. The consistency of salt rejection is confirmed by low frequency of ion exchange exhaustion. Ion exchange
bottle usage has averaged 35 bottles per month
with average monthly water production exceeding
10,000,000 gallons.
Figure 4 shows the overall conductivity removal by
one TMT unit since startup. This steady high level of
performance and the steady RO performance is a
good indicator of high overall TMT performance.
Figure 4: Conductivity Percent Cuts vs. Hours TMT2
North Anna Power Station, Virginia
Ion Exchange Trailer
The ion exchange trailer contains the final step in
the water treatment process. In this step either the
primary or polishing banks of resin remove any
remaining impurities. Performance of the IE unit is
seen in the final product water quality as it leaves
the trailer system.
Table 1 shows average product quality as measured by VA Power versus plant specifications for
the past six months. The only parameter to exceed
these specifications during this period is dissolved
oxygen, which for eight days was high due to
a piping reconfiguration in the CORS unit (see
CORS Results).
Figure 3: SDI Five and Fifteen Min. North Anna Trailers
The EDR unit performance can be measured in
terms of TDS reduction and organic removals. The
EDR units in this system have averaged a 77%
rejection of salt based on conductivity since
startup. TOC reduction has ranged from 20% to
38% and has averaged 27.6%. The EDR units have
required cleaning every three months. Chlorine addition has helped the EDR unit by reducing bacterial growth in the stacks and thereby increasing
salt rejection in the unit and also reducing the EDR
cleaning frequency.
The performance of the RO unit can be looked at in
terms of TOC reduction, silica rejection and salt
Page 4
CORS Background
The CORS unit at this site is unique in many ways. It
is only the second such unit to be employed at a
power plant in the United States. It is the first trailerized CORS unit and the first unit to be dedicated
solely to deoxygenating the makeup water to a
power station.
The CORS process was developed as an alternative
method of deoxygenating water for condensate
makeup water streams.11 The process achieves
oxygen removal to less than 1.0 ppb at ambient
temperatures by reacting either hydrogen or
hydrazine with oxygen.12
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In the system under discussion hydrogen is used
and is reacted with oxygen to form water.
Figure 5: North Anna Power Station Cors Flow
Diagram
H2 + .5 O2 -> H2O
By this algorithm the amount of hydrogen dosed
into the flow stream is increased with increasing
oxygen inlet and outlet levels, decreased with
increasing outlet hydrogen levels and increased
with increasing system flow rates. The different
degree to which each of the above parameters
affects the performance of the unit is taken into
account in the dosage algorithm. The logic of the
dosage algorithm is to dose at a near stoichiometric of hydrogen based on inlet oxygen level and
flow rate and to correct the dosage level based on
the outlet oxygen and hydrogen levels.
The reaction is catalyzed using a palladium doped
anion resin specifically developed for this purpose.
The process requires only stoichiometric quantities
of hydrogen and produces no byproducts.
This process is used commercially in the United
States, Germany and South Africa.11,13,14
CORS Description
The CORS system flow sheet is shown in Figure 5.
Water entering the CORS trailer is sent into the
CORS feed tank (500 gallons [1.9 m3]). Water is then
pumped from this tank to the hydrogen/water
mixer, hydrogen being injected just prior to the
mixer. The water then enters the catalytic resin
vessel where the hydrogen and oxygen react in the
resin bed. From the vessel the de-oxygenated water flows either out of the CORS unit and into the
ion exchange trailer or it is recycled back to the
suction of the CORS feed pumps. The amount of
water that is recycled is controlled using a float
control valve in the CORS feed tank. By this method
the flow rate of product water flowing from the
CORS unit is kept equal to the incoming flow rate to
the CORS unit. The amount of water being pumped
into the resin bed remains a relatively constant
370-390 gpm at all times.
Hydrogen is injected using a 0.2 micron porous
sparger. The amount of hydrogen injected into the
system is based on an algorithm, which takes into
account four parameters:
1. Resin bed inlet oxygen level
2. Resin bed outlet oxygen level
3. Resin bed outlet hydrogen level
4. Water flow rate through the resin bed
Hydrogen is supplied to the CORS unit using
hydrogen (256 cu. ft. H2/cylinder) cylinders. Eight to
sixteen bottles of hydrogen are manifolded
together at a hydrogen storage facility located
some 200 ft. from the CORS unit (location chosen
due to safety considerations). The hydrogen is
piped to the CORS unit where it enters the CORS
unit hydrogen dosing cabinet. The hydrogen dosing
cabinet contains the mass flow meter which regulates hydrogen flow based on the hydrogen dosage algorithm. Hydrogen flows from the mass flow
meter out of the hydrogen dosing cabinet to the
point of injection just prior to the hydrogen/water
mixer. The entire hydrogen line inside the trailer is
contained and force vented with air to outside the
trailer to prevent any buildup of hydrogen within
the trailer if a leak of hydrogen should occur. The
vented air, as well as the air inside the trailer, is
continuously monitored for the presence of hydrogen. If any hydrogen is detected, the system will
immediately be shutdown. In addition, a high number of items including automatic shutoff valves,
interlock
switches,
external
hydrogen
pressure relief valve, pressure switches and general fail/safe design, are incorporated in the
hydrogen handling system to enhance safety of
the CORS system.
The hydrogen/water mixer used in this system is
static in line type. Complete dissolution of hydrogen is the goal of this mixer although it is not necessary for operation of the unit. Any undissolved
hydrogen that exits the mixer will enter the catalytic resin vessel. A continuous flow bleed line to a
forced air purge tank is provided to prevent any
buildup of hydrogen in this vessel. In addition continuous flow bleed lines are provided at other
TP1070EN
Page 5
points in the system where hydrogen could potentially buildup.
The resin vessel is a typical carbon steel, rubberlined ion exchange vessel. The vessel contains
approximately fifty cubic feet of resin and is sized
to allow for 100% expansion of the bed during
backwashing. Sight glasses in the vessel allow for
examination of the resin during normal operation
and backwashing.
The entire CORS operation is monitored and controlled utilizing a programmable logic controller
and an industrial grade personal computer with a
color display terminal. The system status is shown
on the output terminal in ten graphic panel displays. Operators use these displays to monitor system performance and to change various
parameters such as alarm levels, timer settings
and various parameters in the hydrogen dosage
algorithm. In addition, data is continuously logged
and stored by the computer. This historical data
can then be displayed on the output screen in
graphical form. This capability is a great tool for
the operator in monitoring the system and finding
process trends. The computer stores data for a
two-week period. Data for long-term periods is
downloaded onto floppy disks. Much of the CORS data
shown in this paper was obtained in this manner.
CORS Results
The CORS process is actually a simple and straightforward process and has proven to be relatively
simple to operate. The limiting step in the process
is the dissolution of hydrogen into the flow stream
prior to the flow stream entering the resin bed. In
the resin bed the reaction between hydrogen and
oxygen is rapid and complete. At no time during
operation has any dissolved hydrogen been
detected in the CORS product stream unless the
residual oxygen level has been 10 ppb or less.
90-95% and at 360 gpm 100% of hydrogen dosed
into the flow stream dissolved. The low hydrogen
dissolution efficiency at 120 gpm prevented complete deoxygenation of the water. As a temporary
solution, the system was operated only at the flow
rates of 240 and 360 gpm. At these flow rates
complete deoxygenation to less than 1 ppb was
routinely accomplished.
A more permanent solution to maximizing hydrogen dissolution at all operating flow rates was to
reconfigure the CORS to allow a high constant flow
rate through the mixer unit at all times. This
change (accomplished in December, 1989) simply
required recycling a portion of the flow stream
through the CORS system, as shown in Figure 5
and discussed previously. With this configuration,
hydrogen dissolution is near 100% at all times.
Typically, effluent oxygen levels are less than 1 ppb.
A typical set of data for a complete day’s operation
is shown in Figures 6, 7, 8, and 9. Figure 6 shows
the oxygen level of the system entering the CORS
resin bed. This level varies depending on the product water flow rate from the CORS unit. As the
product water flow rate approaches the total CORS
flow rate, the oxygen level in the resin bed feedwater approaches that of the raw feedwater. This can
be seen by comparing Figure 6 with Figure 7,
which shows both the product flow rate and the
total CORS flow rate as it enters the resin bed. The
CORS outlet oxygen level and outlet hydrogen level
for this same period can be seen in Figure 8. This
level is essentially constant at less than 1 ppb
throughout the entire day’s operation. The hydrogen level is held at a low, relatively constant value
during all periods of operation (CORS system will
automatically shutdown if outlet hydrogen level
exceeds 100 ppb). The hydrogen dosage rate for
this period is seen in Figure 9. The amount of H2
used over the 24-hour period was less than 2 lbs. (0.9
kg) at a cost of less than ten dollars worth of hydrogen.
In the initial operation of this CORS unit, water
passed through the unit in a once-through flow
pattern. Water that entered the feed tank was
pumped through the mixer, resin bed and out to
the IE trailer, no water was recycled back to the
feed as previously described. With this flow
scheme, operation was impeded due to inefficient
hydrogen dissolution at low flow rates.
At the flow rate of 120 gpm, less than 50% of the
hydrogen dosed into the flow stream was being
dissolved. At 240 gpm, this percentage shot up to
Page 6
TP1070EN
Figure 6: CORS Inlet O2 Level
Figure 7: CORS Flow Rates
Figure 9: CORS Hydrogen Dosage Rate
A second set of CORS data is presented in Figures
10, 11, 12 and 13. This data is from a 12-hour
period during which the system operated in three
different product flow ranges. As can be seen in
Figure 11, the CORS unit product flow rate ran in
the ranges of 120, 240 and 360 gpm (0.5, 0.9 and
1.4 m3/h). These ranges correspond to one, two or
all three TMTs being operated (the frequent small
drops shown in product flow rate is due to reduced
product flow from a TMT trailer during EDR reversal). As expected, the change in flows had a strong
impact on the inlet oxygen level into the CORS resin
bed (see Figure 10).
However, the outlet oxygen level was essentially
constant throughout this entire period (see Figure
12). Outlet hydrogen level did vary somewhat but
within a relatively small band. Hydrogen usage was
continuously adjusted for the flow changes (see
Figure 13).
Figure 8: CORS Outlet H2 and O2 Level
Figure 10: CORS Inlet O2 Level
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Page 7
Overall the CORS unit has performed very well,
especially since the unit was reconfigured. Routine
maintenance on the unit is limited to instrument
calibration on a biweekly to monthly basis.
Summary
Figure 11: CORS Flow Rates
Overall operation of the system has been consistent and reliable. Each subsystem in the process is
performing as intended. The RO consistent performance is due to the consistent performance of
both the ultrafiltration and EDR pretreatment systems within the TMT units. Multimedia filtration
units are preventing rapid fouling of the ultrafiltration units.
The CORS unit has consistently reached oxygen
levels to less than 1 ppb which is considerably
lower than conventional deoxygenation processes
normally achieve. Final IE product quality has
been extremely consistent and much below
plant specifications.
Acknowledgement
Figure 12: CORS Outlet H2 and O2 Level
The authors would like to thank Mr. L.D. Lee, Plant
Chemist, Virginia Power for his assistance in preparing this paper.
References
Figure 13: CORS Hydrogen Dosage Rate
These two sets of data highlight the consistent performance of the CORS unit under both steady and
changing conditions. It is important to remember
while examining this data that the CORS system is
operating completely automatically and that no
operator interface is required during routine operation. The unit is able to maintain low outlet oxygen
levels at all times and the control system rapidly
responds to changing flow conditions.
Page 8
1. Jones, L.B. and Bossler, John F., “Containerized
Treatment System Overcomes Problems, Delivers High Purity Water to Nuclear Power Plant.”
48th International Water Conference, Pittsburgh, PA, November 1987.
2. Wiser, S.L., Lee, Y.H., Stroh, C.R. and O’Brien, M.,
“Removal of Organics from Secondary Makeup
Water Case Study.” 46th International Water
Conference, Pittsburgh, PA, November 1985.
3. Katz, W.E. and Clay, F.G., “Commercial Production of Ultrapure Water by Fully Automatic Triple Membrane (UF/EDR/RO) Demineralizers.”
46th International Water Conference, Pittsburgh, PA, November 1985.
4. Katz, W.E. and Clay, F.G., “TOC Removal From
Surface Waters by Commercially Operating
Triple Membrane Demineralizers.” 49th International Water Conference, Pittsburgh, PA,
October 1988.
5. Smith, G.O. and Wilson, K.S., “Makeup Water
Treatment
Utilizing
Triple
Membrane
Demineralizers at SERI’s Grand Gulf Nuclear
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6.
7.
8.
9.
10.
11.
12.
13.
14.
Station.” Electric Power Research Institute Condensate Polisher Workshop, Little Rock, AR,
May 1989.
Katz, W.E., “The Electrodialysis Reversal (EDR)
Process.” International Congress on Desalination and Water Reuse, Tokyo, Japan, November/December 1977.
Katz, W.E., “Electrodialysis—The First TwentyFive Years.” Fifth Annual Meeting, National
Water Supply Improvement Association, San
Diego, CA, July 1977.
Elyanow, D., Parent, R.G., and Mahoney, J.
“Parametric Tests of an Electrodialysis Reversal
System with Aliphatic Anion Membranes.”
Report to OWRT, U.S. Department of the Interior, Washington, D.C., August 1980.
Brown, D.R. and McElhinney, K.D., “Desalting
High Salinity Brackish Water Using 10-Stage
EDR.” Ninth Annual Conference, National Water
Supply Improvement Association, Washington,
D.C., May/June 1981.
Carpenter, F. and Geishecker, E., “A Quarter
Century of Electrodialysis Desalting: The Buckeye, Arizona Experience, Water Desalination in
Buckeye, Arizona.” 108th Annual Conference of
the AWWA, Los Angeles, CA, July 1989.
Harahay, A. and Woffe, C., “Catalytic System
Deoxygenates Makeup Water to 10 ppb.”
Power Engineering, December 1987.
deSilva, S.G. and Siber, A., “Reduction of Oxygen
with Hydrogen at Ambient Temperatures Using
Lewetit OC—1045 Catalyst— A Potential Oxygen Control Method for Water Systems.” 45th
International Water Conference, Pittsburgh, PA,
October 1984.
Martinola, F.B. and Thomas, P., “Saving Energy
by Catalytic Reduction of Oxygen in Feedwater.” 45th International Water Conference,
Pittsburgh, PA, 1980.
Kelly, S.F.M. and Aspden, J.D., “The Control of
Dissolved Oxygen in the Makeup Water for
Cycle Operating Power Plants.” Proceedings
American Power Conference, Chicago, 1985.
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