WATER POLLUTION CONTROL RESEARCH SERIES
12060 OXL 01/71
Reduction of Salt Content
of Food Processing
Liquid Waste Effluent
ENVIRONMENTAL PROTECTION AGENCY • WATER QUALITY OFFICE
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Water Pollution Control Research Series
The Water Pollution Control Research Reports describe
the results and progress in the control and abatement of
pollution in our Nation’s waters. They provide a central
source of information on the research, development, and
demonstration activities in the Water Quality Office, in the
Environmental-Protection Agency, through in—house research
and grants and contracts with Federal, State, and local agencies,
research institutions, and industrial organizations.
Inquiries pertaining to Water Pollution Control Research
Reports should be directed to the Head, Project Reports System,
Water Quality Office, Environmental Protection Agency,
Washington, D. C. 20242.
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Reduction of Suit Content
of Food Processing Liquid Waste Effluent
by
National Canners Association
Western Research Laboratory
Berkeley, California 94710
for the
WATER QUALITY OFFICE
ENVIRONMENTAL PROTECTION AGENCY
Project #12060 DXL
January, 1971
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, B.C. 20402 - Price 55 cents
Stock Number 5501-0136
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EPA Review Notice
This report has been reviewed by the Water Quality
Office, EPA, and approved for publication. Ap-
proval does not signify that the contents necessarily
reflect the views and policies of the Environmental
Protection Agency, nor does mention of trade names
or commercial products constitute endorsement or
recommendation for use.
11
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ABSTRACT
Olive brines containing 0. 05 to 0. 7 percent sodium chloride were passed
through a mixed bed of cation and anion exchange resins. The effect of
influent composition on the composition of effluent from the ion ex-
change unit was investigated using a range of influent pH, salt content,
and C.O.D. levels. Influent pH was not a factor in the performance
of the unit due to rapid pH increase from the calcium hydroxide in the
resin bed. The unit was operated at sodium chloride levels of 500 to
7, 000 ppm with random pH and C. 0. D. levels. The highest removal
of sodium chloride (94 percent) was obtained at a level of 2, 700 ppm
sodium chloride in the influent. With pH and C. 0. D. held constant,
the salt content of the influent was varied between 500 and 5, 000 ppm.
The effluent sodium chloride content was approximately 150 ppm at
600, 1,000 and 2,700 ppm and was 790 ppm at 6, 000 ppm influent con-
centration.
There was evidence that the extent of sodium chloride removal was
decreased as the C. 0. D. of the influent increased, but this relation-
ship was not rigorously established.
C. 0. D. and B. 0. D. measurements were made on influent and effluent
samples, and an average B. 0. D. IC. 0. D. ratio of 0. 35 was establish-
ed for olive processing water.
The resins were regenerated using a solution of calcium hydroxide.
To establish the maximum salt concentration attainable in the regen-
erant effluent, the regenerant was repeatedly recycled through the
resin bed. The sodium chloride content of recycled regenerant solu-
tions was increased 40 percent over the influent brine level and
evidence was obtained that at least a ten-fold increase was possible.
The cost of desalination of dilute food processing brines by ion exchange
treatment, with calcium hydroxide as the regenerant, was estimated at
$0. 26 per 1,000 gallons of influent.
This report was submitted in fulfillment of Project Number 12060 DXL
under the partial sponsorship of the Water Quality Office, Environ-
mental Protection Agency.
111
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CONTENTS
Section Page
I Conclusions 1
II Recommendations 3
III Introduction 5
IV Operational and Evaluation Phase 17
V Discussion 35
VI Acknowledgments 41
VII References 43
VIII Patents and Publications 45
V
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FIGURES
Page
1 Photograph of the Ion-Exchange Pilot Unit 7
2 Schematic Representation of the Ion-Exchange
Pilot Unit 8
3 A Laboratory Assembly of an Ion-Exchange Unit 10
4 Schematic of a Uni-Flow Filter 12
5 Photograph of a Uni-Flow Filter 13
6 Schematic of Operation of a Uni-Flow Filter 14
7 Flow Diagram of the Complete Ion-Exchange and
Regeneration Operation 15
8 The Gradual Salt Reduction During an Individual Run
- Batch A 23
9 The Gradual Salt Reduction During an Individual Run
- Batch B 24
10 The Gradual Salt Reduction During an Individual Run
- Batch C 25
vi
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TABLES
No. Page
1 Comparison of Competitive Ion Exchange Processes
for Water Desalination 6
2 Specifications of the Aqua-Ion Ion Exchange Pilot
Plant 9
3 Analysis of Composite Samples Collected During
the 600 ppm Salt Level Period 18
4 Analysis of Composite Samples Collected During
the 1,000 ppm Salt Level Period 19
5 Analysis of Composite Samples Collected During
the 2,700 ppm Salt Level Period 20
6 Analysis of Composite Samples Collected During
the 6, 000 ppm Salt Level Period 2 1
7 Reduction in Salt Content During an Individual Run 22
8 B.O.D. 5 :C.O.D. Ratio for Olive Processing
Wastewaters 27
9 Analysis of Composite Samples of Four Different
Salt Levels with C. 0. D. and pH Held Constant 28
10 Increase in the Sodium Chloride Content of
Regenerant Effluent as a Result of Regenerant
Recycling 30
11 Sodium Chloride Content of the Regenerant Influent
and Effluent at Various Cycle Times 31
12 Reduction in Salt Content of Influent Brine Obtained
During the Continuous Operation of the Unit at
Different Flow Rates 32
vii
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Page
13 Calcium Ion Concentration and Hardness of the
Influents and Effluent of Both the Desalination and
Regeneration Processes 33
14 Analytical Values for Brines Used in Maraschino
Cherry and Dill Pickle Production 34
15 Effect of the Carbonate Regeneration on the
Calcium Content of the Product Water 37
16 Cost Estimate for 100, 000 GPD Plant 39
V II I .
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SECTION I
CONCLUSIONS
1. The highest percentage salt removal from olive processing
waters was achieved at an influent level of approximately 2, 500 ppm.
2. Repeated recycling of the regenerant resulted in increasing the
salt content of the regenerant influent to a level of approximately 3, 000
ppm with no indication of leveling off.
3. Pretreatment of olive processing water with activated carbon
reduced deposit formation on distributors and made possible flow rates
up to 10, 000 gpd.
4. Pre-liming and filtration of the brine used to prepare regenera-
tion solutions decreased regeneration cycle times to about 30 mm.
5. The B. 0. D. IC. 0. D. ratio of the product water varied with
salt content and extent of pre-treatment of the influent brine; the
average value of the ration was 0. 35.
6. The high calcium content of the product water could be reduced
by passing a gas mixture containing carbon dioxide into the raw ef-
fluent from the ion exchange unit.
—J -.
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SECTION II
RECOMMENDATIONS
1. The possibility of reusing the product water (with further treat-
ments if necessary) should be tested and carefully evaluated.
2. Modifications should be made on the unit specifically to the dis -
tributors and the capacity of the desalting chamber, in order to
produce 10, 000 gpd of water of good quality.
3. More work should be done on brine pre -treatment (e.g., the
activated carbon column) emphasizing cost factors and evalua-
ting effect on flow-rate.
4. Results obtained on the regenerant recycling were not sufficient
to establish the highest salt concentration attainable in the re-
generant effluent; therefore, more work should be done on
regeneration.
5. Carbonation of the final effluent should be carefully tested and
evaluated as means of increasing the effluent quality and reuse
potential.
-3-
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SECTION III
INTRODUCTION
Many foods are prepared for consumption using sodium chloride solu-
tions for storage, fermentation or quality grading. The liquid waste
produced from such operations presents a difficult disposal problem.
The discharge of the saline wastes must be done in such a way that
water quality standards are maintained in the receiving waters.
The magnitude of the potential for saline pollution from food processing
operations is reflected in the data presented by T. J. Powers iii discus -
sion of cucumber-pickling wastewater treatment and disposal.
It has been estimated that in 1962 nine olive companies in California’s
Central Valley discharged about 226 million gallons of water with a
level of 2, 300 ppm of sodium chloride as the average concentration.
A typical composite waste effluent from an olive plant had the follow-
ing characteristics (all in ppm ): C. 0. D.= 2, 400; B. 0. D. = 1, 250,
suspended solids = 110; Chloride = 3,500. The sodium chloride dis-
charged from food processing plants has a wide geographical base
and only in specific areas is the problem acute. In those areas where
low dissolved solids water is available in sufficient quantity to dilute
the saline wastes to a final level of 100 - 175 ppm (chloride ion), there
is little danger of violating water quality standards. However, in many
areas there is insufficient fresh water available to dilute the saline
waste to non-polluting levels. It is in these areas that a new technol-
ogy of liquid waste handling must be demonstrated and applied.
This project presents a potentially useful technology to alleviate
potential saline pollution from food processing liquid wastes. The
technology is based on the removal of inorganic ions and ionizable
organic compounds with a mixed bed of cation and anion exchange resins.
The key feature of the technology is its use of calcium hydroxide as a
regenerant for the spent resin. This technology holds promise of
treating saline food processing wastes to produce a salt-free water
which could be reused and a concentrated salt solution which could be
returned to process after suitable treatment.
The ion exchange technology was demonstrated on olive processing
water due to the critical situation in the disposal of these liquid wastes
-5-
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in the Madera and Tulare Counties of California. The ion exchange
processing of saline wastes has the potential for extension, with little
modification, to the treatment of brines from the processing of cucurn-
bers.
New processing technology, such as in-the-jar fermentation of pickles
and olives, 2, and salt-free storage of olives 4 may provide solutions
to part of the potential saline pollution from pickle and olive produc -
tion. In the case of olives, it is still necessary to use sodium hydrox-
ide to hydrolyze bitter olive constituents, so the problem of management
of large volume, low salt content, processing waters still must be
solved.
Ion exchange is the most promising method currently available to treat
saline wastes such as olive processing waters which contain dissolved
organic compounds as well as inorganic salts. There are five ion
exchange processes which have been proposed for water desalination.
The characteristics of these processes are tabulated in Table 1 taken, in
part, fromJ.I. BregmanandJ.M. Shackelford, Envir. Sci. Tech. 3(4)
336 (1969).
TABLE 1
COMPARISON OF COMPETITIVE
ION EXCHANGE PROCESSES FOR WATER DESALINATION
Name of TDS in Operation Cost
Process feed, ppm Scale, mgd $11000 gallons
Sul-bi-Sul 100-1000 5 0.29
Desal 150-10,000 5-10 0.13-0.78
Sirotherm 1000 5 0.25
Asahi-Grover 1000 5 0.25-0.35
Aqua-Ion 100-10,000 0.4 0.13-0.17
It is clear from an examination of the information summarized in Table
1 that the Aqua-Ion process has a lower cost (at a much smaller scale
of operation) than the other processes listed. The low cost at small
scale of operation is very important because the maximum output
of dilute saline waste from a single olive processing plant would
probably not exceed 500, 000 gpd. Figure 1 is a photograph of the pilot
unit which was constructed by Aqua-Ion to treat up to 10, 000 gpd of
saline waste under contract to NCA in this Environmental Protection
Agency supported project. Figure 2 is a schematic representation of
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Figure 1. Photograph of the Ion-Exchange Pilot Unit
/
)
i
-7-
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Figure 2. Schematic Representation of the Ion-Exchange Pilot Unit
EXCESS LIME AND
CONCENTRA7-Eo SALT
WATER
A
our
EXCESS LIME
AND
CO#.VEN7RA7EO
SALT TO FILTIR
A—F
oIsrR/8 JroRs
WASTE AND
LIME IN
1—4= REs/N
MOVEMENr
V4L YES
WASTE IN
CONCENTRA:
SALT AND
SOLU8LE LIME
To PROCESS
THICKENED
LIME
BACK ro
PROCESS
-8-
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TABLE 2
SPECIFICATIONS OF THE AQUA-ION ION EXCHANGE
PILOT PLANT
Higgins Loop Diameter: 1 ft
Height of Desalination Leg: 9 ft
Resin Volume: 17.3 cu ft
Exchanger Ratio: 65 percent cationic
35 percent anionic
Resin Movement per Cycle: 22 in.
Uni-Flow Filters: Primary -20 hoses
Secondary - 7 hoses
Power Rating: 7 horsepower
the Aqua-Ion pilot unit; specifications of the unit are tabulated in
Table 2. Figure 3 shows a photograph of a laboratory assembly of
an ion-exchange unit.
The treatment consists of passage of waste over a mixed bed of cation
and anion exchange resins. The cation exchanger was in the calcium
form and was a sulfonated polystyrene resin (Duolite C -20). The anion
exchanger was in the hydroxyl form and was an aminated polystyrene
resin (Duolite A-l02-D). The polar constituents of the waste, shown
for simplicity as sodium chloride, react with the exchangers as
follows:
(cation) R 2 Ca + 2 NaCl = 2 RNa + CaC1 2
(anion) 2 ROH + CaC1 2 = 2 RC1 + Ca(OH) 2
Depending on the solute concentration, the calcium hydroxide formed
during the removal of sodium chloride will stay in solution or (if the
-9-
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1:
Figure 3. A Laboratory Assembly of an Ion-Exchange Unit
i: [ . ft
1
*ti1
‘1
I
I
- -
-10-
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concentration exceeds 0.0443 N at 25°C) will precipitate. The pre-
cipitated calcium hydroxide (and other insoluble salts) can be removed
using a Uni-Flow filter 5 . These filters are inexpensive and simple to
use. The slurry enters the filter distributor at the top and flows down
through the individual hoses. The clear liquid passes through the cloth
and runs down the outside of the hose to a collection point. The sludge
moves along inside the hose and is discharged periodically at the bot-
tom (see Figures 4, 5 and 6).
The product of the ion exchange operation is a solution of calcium
hydroxide and organic material. Part of the organic material origi-
nally present in the waste is converted to insoluble organo-calcium
salts which can be removed by filtration. The calcium hydroxide can
be removed from the ion exchange effluent by carbonation and filtra-
tion of the resulting calcium carbonate or by ion exchange of the
calcium for magnesium. Formation of the insoluble magnesium hy-
droxide to remove calcium hydroxide is feasible in locations where
either the wastewater or the water supply contains high levels of
magnesium. In locations which have high bicarbonate hardness, the
effluent from the ion exchange unit can be blended with hard water to
produce cold lime softening as shown by the following equation:
Ca(OH) 2 + Ca(HCQ 3 ) 2 = 2 CaCO 3 + 2 H 2 0
The resin must be regenerated to convert it into a form usable for
further sodium chloride removal. Regeneration is accomplished with
a solution or suspension of calcium hydroxide in the saline wastewater.
The regenerant effluent is saturated with calcium hydroxide and con-
tains the salts and part of the organic compounds originally present
in the saline wastewater. The regenerant is recycled many times in
order to increase the sodium chloride concentration to a level which
makes salt recovery or reuse attractive economically. The regener-
ated resin is rinsed with tap water to remove residual calcium
hydroxide and is then ready for treatment of saline wastewater.
Figure 7 shows a flow diagram of the complete ion exchange and
regeneration operation.
—11 -
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Clear liquid
collector
Filter hoses
Sludge collector
Figure 4. Schematic of a Uni-Flow Filter
Slurry input
Clear liquid out
Sludge
-12-
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Figure 5.
Photograph of a Uni—Flow Filter
I
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iI9
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SLURRY
.
VALVE [ %%J)J
d
Figure 6.
Schematic of Operation of a Uni-Flow Filter
TUBE
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p.1
S
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p S.
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SI
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j. S .
RI.
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0
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FILTRATE
i
SLUDGE
-14-
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Brine
Pre-treatment
Tank
4 j
Figure 7. Flow Diagram of the Complete Ion-Exchange and
Regeneration Operation
I
Brine
Storage Tank
-15-
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SECTION IV
OPERATION AND EVALUATION PHASE
Effect of Different Influent Salt Levels on Salt Removal
The unit was tested at different influent salt levels to determine th
effect on sodium chloride removal. Runs were made with olive pro-
cessing brines having sodium chloride levels of approximately 600,
1,000, 2,700 and 6,000 ppm. During these runs sodium chloride
concentration was the only parameter held constant. A complete run
comprises desalination, regeneration, and rinsing. Four composite
samples were collected from each run and designated as: (1) influent
to the unit, (2) effluent from the ion exchange unit (product), (3) re-
generant influent, and (4) regenerant effluent.
The first salt level tested was approximately 600 ppm sodium chloride
in the influent; this concentration was obtained by diluting olive pro-
cessing water. During this series of runs the deionized effluent
(product) and the regenerant influent were not filtered. Table 3
tabulates the results obtained from the analysis of composite samples
collected.
These runs indicate that the sodium chloride content of olive process-
ing water could be reduced from approximately 600 to 145 ppm. The
amount of desalinated product obtained from each run was 30 to 140
gal. at a flow rate of 4 to 6 gpm. The same 150 gal. of regenerant
were used for each run by recycling the effluent as influent for each
successive regeneration. The color of the influent brine was light
blue when the pH was relatively low and reddish-brown when the pH
was high. The final effluent was usually colorless, but a few samples
had a yellow color. The color of the regenerant influent and effluent
was brown.
The second salt level studied was approximately 1, 000 ppm as sodium
chloride. Filtration was used to remove the insoluble organo-calcium
compounds from the regenerant suspension and the solids from the
product. The usual four samples were collected from the last run
on each day of sampling by NCA personnel. Table 4 tabulates the
results obtained by analysis of these samples. The salt content was
reduced to a level of 168 ppm on the average in this series of runs.
In runs B, C, D and E, hydrochloric acid was added to the olive
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TABLE 3
ANALYSIS OF COMPOSITE SAMPLES COLLECTED
DURING THE 600 PPM SALT LEVEL PERIOD
Sample NaC1, SS, C.O.D.,
Run No. Number pH ppm ppm ppm
600_A* 1 7.4 610 9 154
2 10.9 60 128 2
3 11.6 610 29 85
4 11.6 605 47 104
600-B 1 9.5 590 7 183
2 11.4 113 113 101
3 12.0 6370** 4244*** 141
4 12. 1 6960** 5868*** 134
600-C 1 11.0 600 14 158
2 12. 1 330 225 150
3 11.8 630 852 161
4 12. 1 590 5956** 173
* A, B, and C are three different sets of samples collected on three
different days. Samples represent the last run on each of these
days.
** These unusually high values were due to residues of hydrochloric
acid used to clean distributors.
*** These high values were due to suspended excess calcium hydrox-
ide.
processing water to adjust the pH to about 7. The volume of desalinated
product from an individual run was 45 to 60 gal. at a flow rate of 3 to
4. 5 gpm. Regeneration was accomplished using recycling of the 150
gal. used for the run 1000-A.
Several runs were completed with a salt level of approximately 2, 700
ppm sodium chloride in the influent. The desalinated product averaged
155 ppm sodium chloride content as shown in Table 5. The color of
the influent brine was reddish-brown and the desalinated product was
yellow. The regenerant influent and effluent were both yellow. The
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volume of product was 20 to 50 gal. at a flow rate of 3 to 4. 5 gpm.
Regeneration was accomplished by recycling 150 gal. of regenerant
four times.
TABLE 4
ANALYSIS OF COMPOSITE SAMPLES COLLECTED
DURING THE 1000 PPM SALT LEVEL PERIOD
Sample NaC 1, SS, C. 0. D.,
Run No. Number pH ppm ppm ppm
1000-A 1 10.6 1195 60 333
2 11.5 190 3 115
3 12.0 1180 30 340
4 12.0 1117 150 290
1000-B 1 6.9 1190 2 356
2 11.0 50 10 131
3 12.0 1150 20 370
4 12.0 1165 200 350
1000-C 1 6.8 1305 2 265
2 12.0 90 0 86
3 12.1 1340 0 214
4 12.1 1320 10 187
1000-D 1 7.2 1195 16 N.R. *
2 12.4 305 0 N.R.
3 12.4 985 6 N.R.
4 12.5 1095 9 NR.
1000-E 1 7.4 1170 19 N.R.
2 12.5 205 4 N.R.
3 12.5 995 17 N.R.
4 12.6 1070 11 N.R.
* N.R. - Not recorded.
An influent brine of approximately 6, 000 ppm sodium chloride content
was passed through the ion exchange unit as the fourth salt level to be
tested. The results from analysis of eight groups of samples col-
lected during this part of the project are tabulated in Table 6. The
desalinated product had an average salinity of 790 ppm as sodium
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TABLE 5
ANALYSIS OF COMPOSITE SAMPLES COLLECTED
DURING THE 2700 PPM SALT LEVEL PERIOD
Sample NaC1, C.O.D., Ca, CaCO 3 ,
Run No. Number pH ppm ppm ppm ppm
2700-A 1 8. 1 2500 1236 35 88
2 12.4 295 735 766 1910
3 12.4 1775 1093 470 1180
4 12.4 1975 968 920 2290
2700-B 1 7. 8 2750 359 24 59
2 12.0 86 210 210 520
3 12.3 2290 1258 660 1646
4 12.4 2500 1176 870 2170
2700-C 1 7.6 2725 1367 24 59
2 11.8 125 512 106 265
3 12.3 2450 1367 412 1029
4 12.4 2605 1179 884 2205
2700-D 1 8.2 2795 1333 12 29
2 11.7 160 453 47 118
3 12.5 2290 1201 590 1470
4 12.5 2300 1101 719 1793
2700-E 1 8.0 2750 562 12 30
2 11.8 130 320 51 130
3 12.2 2390 485 283 706
4 12.5 2400 440 1184 2950
chloride. The volume of regenerant used for this series of runs was
reduced to about 100 gal. per run and was recycled in sets of 3 or 4
runs.
To follow changes in the extent of salt removal which occur during
the duration of individual runs, grab samples were collected for each
10 gal. of effluent up to 50 gal. In addition, the usual 50 gal. com-
posite sample was obtained. These samples were analyzed for chloride
ion; the results are tabulated in Table 7. Figures 8, 9 and 10 illustrate
the results graphically.
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TABLE 6
ANALYSIS OF COMPOSITE SAMPLES COLLECTED
DURING THE 6000 PPM SALT LEVEL PERIOD
Sample
NaC1,
C.O.D.,
Ca,
CaCO 3 ,
Run No.
Number
pH
ppm
ppm
ppm
ppm
6000-A
1
2
3
4
7.0
11.9
12.0
12. 1
6810
490
5700
4650
1489
234
1251
1003
12
318
704
1072
29
794
1705
2675
6000-B
1
2
3
4
7.3
12.3
12.4
12.5
6710
750
5610
5610
1510
602
1219
1111
12
365
754
1084
29
911
1882
2705
6000-C
1
2
3
4
7.0
11.9
12. 1
12. 1
7050
850
5720
5250
1436
266
1231
1029
12
236
625
1108
29
590
1560
2764
6000-D
1
2
3
4
7. 1
12.0
12.2
12.2
5890
840
5790
5820
1143
474
1209
1067
18
212
660
2286
44
529
1646
5703
6000-E
1
2
3
4
7.7
11.2
11.7
11.8
4950
1150
2590
3010
1238
797
178
257
22
184
921
1333
54
460
2299
3327
6000-F
1
2
3
4
7.4
11.7
11.8
11.8
5590
490
5420
5310
1163
176
1069
930
12
212
707
1108
29
529
1764
2764
6000-G
1
2
3
4
6.7
11.7
11.7
11.8
5290
890
5650
4690
969
367
1014
731
12
282
695
1120
29
705
1734
2793
6000-H
1
2
3
4
6.9
11.9
11.9
12.0
5250
840
5720
3990
929
346
927
546
12
212
577
1025
29
529
1441
2558
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TABLE 7
REDUCTION IN SALT CONTENT DURING
AN INDIVIDUAL RUN
Batch A
Batch B
300
288
240
215
203
248
1240 10 284
20 248
30 221
40 209
50 209
comp. 237
1017 10
20
30
40
50
331
281
255
231
221
265
2 1132 10
20
30
40
50
comp.
3 1132 10
20
30
40
50
comp.
306
304
289
259
236
280
284
274
243
223
203
252
2 1450 10 297
20 296
30 273
40 248
50 245
comp. 266
3 1450 10 278
20 273
30 238
40 205
50 185
comp. 239
mE
Eff
Run
Cl,
Cl,
No.
ppm
gal.
ppm
Run
m i
Cl,
Eff
Cl,
No.
ppm
gal.
ppm
Batch C
Eff
Run
Cl,
Cl,
No.
ppm
gal. ppm
1132 10
20
30
40
50
comp.
comp.
2 1240 10 335
20 301
30 259
40 237
50 221
comp. 272
3 1240 10 396
20 389
30 363
40 313
50 246
comp. 348
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INF 1132 ppm Cl
3rd Run
2nd Run _____
1st Run
I I I I
10
50
20 30 40
GALLONS OF EFFLUENT
Figure 8 The Gradual Salt Reduction During An Individual Run
Batch A
400 —
350 —
300 —
250
200
150 —
100 —
-I
0
•
-23-
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400
350 -
300 —
250 —
200
INF 1240 ppm Cl
I I
3rd Run
2nd Run
1st Run
20 30 40 50
GALLONS OF EFFLUENT
Figure 9 The Gradual Salt Reduction During An Individual Run
Batch B
N
rx]
U
150
100 —
10
-24--
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INF lstRun lOllpprnCF
2nd Runs
3rd Ru 4 1450 ppm
3rd Run
2nd Run
1st Run
I I I I I
10
20 30 40 50
GALLONS OF EFFLUENT
Figure 1C The Gradual Salt Reduction During An Individual Run
Batch C
\
400 —
350 —
300
250
200
150
100
U
_•.*_ _. -..-
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Effect of pH on Sodium Chloride Removal
Under the experimental conditions used in this project, pH was found
to have no significant influence on salt removal. This observation can
be explained by the fact that the resin was in the calcium or hydroxyl
form or, at times, in a carbonate form. When the influent olive pro-
cessing water contacted the resin, the pH was increased to the alka-
line side of 7 regardless of the influent pH level. Differences in
performance due to pH changes would be expected if the resin bed had
been fully converted to the sodium and chloride forms; no such condi-
tion was observed during the project.
Effect of Chemical Oxygen Demand Level on Salt Removal
No effect on salt removal would be expected from traces of non-polar
organic compounds present in the influent brine. If neutral organic
compounds were present in the influent in large amounts, they could
coat the resin and decrease the salt removal efficiency. A more
severe problem would exist if the organic compounds in the influent
were polar in nature, since they would compete for active sites on
the resin with sodium and chloride ions. This competition would
reduce the desalting efficiency of the resin bed. Neither extreme of
these two situations was experienced in this project since the C. 0. D.
content of the influent did not exceed 1, 600 ppm. There was evidence
that the salt removal was decreased as the C. 0. D. of the influent
increased, but this relationship was not rigorously established.
A B. 0. D. IC. 0. D. ratio was calculated for olive processing waste -
water having sodium chloride levels of 2, 500 and 5, 000 ppm. A
similar ratio was established for the desalinated product water
obtained from the ion exchange treatment of these brines. The data
collected for the calculation of the ratios is tabulated in Table 8. The
ratio varied with the salt content and the extent of treatment of the
brine samples. The average value of the B. 0. D. IC. 0. D. ratio was
0. 35.
Effect of Ion Exchange Treatment of Olive Processing Waters on
C.O.D. Level in Desalinated Product
The ion exchange treatment of olive processing water was expected
to remove ionized and ionizable organic compounds. The detailed
-26-
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TABLE 8
B.O.D. 5 :C.O.D. RATIO
FOR OLIVE PROCESSING WASTEWATERS
NaC1,
ppm
2500
2500
2500
2500
2500
2500
5000
5000
5000
5000
5000
5000
5000
5000
290
340
330
320
370
310
130
120
110
120
130
150
Average Value 0. 40
0.45
0.35
0. 33
0. 37
0. 35
0. 48
1490
1510
1440
1140
830
1160
970
930
0. 39
470
470
360
310
3 40
480
230
260
0.32
0.31
0.25
0.27
0.41
0. 41
0.24
0.28
230
600
270
470
430
180
370
350
Wastewater Desalinated Product
C.O.D., B.O.fl, B O.D., C.O.D., ]3 .O.D., E .O.D.,
ppm ppm C.O.D., ppm ppm C.O.D.
,
560 200 0.36
760 320 0.42
700 290 0.41
660 260 0.39
630 230 0.37
610 270 0.44
composition of olive processing water is not known, but such com-
pounds as acetic acid, lactic acid, citric acid, saccharic acids, and
hydrolyzed pectins are probably present. The Aqua-Ion technology
would remove these compounds either by binding on the resin (to be
released later during regeneration) or by formation of insoluble cal-
cium salts (removed by filtration). Examination of the data tabulated
in Tables 3 through 6 indicates that substantial quantities of organic
materials in the olive processing waters are removed during the ion
exchange treatment. In some cases, as much as 85 percent of the
initial C. 0. D. material was removed by treatment and filtration.
The effect of residual C.0.D. materials in the desalinated product
water on the reuse potential is of importance, but was not evaluated
in this project.
70
170
70
140
110
70
100
90
0. 30
0. 28
0. 26
0.30
0. 26
0. 39
0. 27
0. 26
Average Value 0.31
0.29
-27-
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Effect of Different Salt Levels in Influent Brines on the Salt
Removal at Constant C . 0. D. and pH
Olive processing brines having an initial sodium chloride content of
approximately 600, 1,000, 2,400 and 5,500 ppm were passed through
the ion exchange unit. Suspended solids were eliminated from con-
sideration as a variable in this part of the study, since the influent
brine was filtered through a Uni- Flow filter before entering the
ion exchange unit. Therefore, C.O.D. and influent pH were the
only compositional factors which were adjusted to relatively con-
stant values. The adjustment of the C. 0. D. content was made by
the addition of lactic acid to the olive brine until a value of about
800 ppm was reached. The pH was adjusted at about 7.5 by the
addition of strong sodium hydroxide solution. One set of samples
was collected and analyzed for each of the four salt levels; the
results are tabulated in Table 9. The effluent was approximately
the same until the salt level in the influent exceeded 2,400 ppm.
TABLE 9
ANALYSIS OF COMPOSITE SAMPLES OF FOUR DIFFERENT
SALT LEVELS WITH C .0. D. AND pH HELD CONSTANT
Sample NaC1, C.O.D., Ca, CaCO 3 ,
Number ppm ppm pH ppm ppm
1 590 805 7.4 22 54
2 190 21? 10.6 44 108
3 490 29 11.9 1323 3300
4 1100 191 11.6 542 1352
1 1070 958 7.5 22 54
2 250 151 10.8 33 81
3 1150 45 11.6 444 1109
4 1350 146 11.8 737 1839
1 2380 797 7.3 22
2 210 465 10.7 44
3 2410 91 11.7 2483 194
4 2450 137 1.1.6 750 1785
1 5510 830 6.9 12 29
2 1150 426 12.3 636 1587
3 5150 1029 12.2 730 1823
4 4650 816 12.3 2510 6262
-28-
-------
Establishment of the Maximum Sodium Chloride Concentration
Attainable in the Regenerant Effluent
The maximum sodium chloride concentration possible in the regenera-
tion effluent is of considerable economic importance in evaluating the
overall usefulness of ion exchange treatment of food processing brines.
Ideally, both the product water and the concentrated regener ant solu-
tion could be recycled in selected stages of the food processing
operation. If both of these objectives cannot be accomplished,
concentrating the salt present in the treated processing water in a
small volume would make further management less costly. To estab-
lish the maximum sodium chloride concentration attainable in the
regenerant effluent, the liquid from each of a large number of resin
regeneration runs was recycled after each individual run. To deter-
mine the increase in salt concentration in the regenerant effluent, a
composite sample was taken from each effluent and the sodium
chloride content was determined. The results of this investigation
are tabulated in Table 10. The average increase in salt content in
the regenerant effluent was approximately 40 percent (difference
between original influent and last effluent of a recycle series), depen-
ding on the salt level and the flow rate.
It was found that the salt increase in the regenerant suspension occurs
at a slow rate. There was not sufficient operating experience with
any single influent brine composition to determine the maximum salt
concentration attainable in the regenerant. A test was run using a
concentration of approximately 20, 000 ppm sodium chloride made by
adding solid salt to an olive processing water. The use of this solu-
tion in regeneration gave an average increase in sodium chloride in
the regenerant effluent of 595 ppm. This result indicated that it was
possible to have substantial salt increases in the regenerant effluent
even at salt levels of approximately 2 percent.
Effect of Cycle Time on Regeneration
The work on regeneration was continued using different cycle times.
Table 11 tabulates the sodium chloride content of regenerant effluent
and influent at various cycle times. The influent sodium chloride
concentration was 1, 900 to 3, 500 ppm in these runs and the flow rate
was 4. 5 gpm. The regenerant effluent was recycled. The cycle time
was calculated by dividing the gal. of influent used in a run by the flow
-29-
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TABLE 10
INCREASE IN THE SODIUM CHLORIDE CONTENT OF
REGENERANT EFFLUENT AS A RESULT OF REGENERANT RECYCLING
Flow Flow
Run Rate, NaC1, ppm Run Rate NaC1, ppm
No. gpm Inf Eff No . gpm Inf Eff
1 A 2 2070 2180 1 R 6 1790 1856
2 A 2300 2360 2 R 1860 2086
3 A 2480 2720 3 R 1879 2106
1 B 2 2410 2820 4R 1948 2131
5 R 1983 2135
1 C 2 2590 2910 1 T 2390 2516
2 C 2600 2750 2 T 2322 2434
3 C 2660 2930 3 T 2416 2486
1 D 2 2540 2770 4 T 2468 2490
2 D 2630 2890 1 U 2521 2633
3 D 2670 3040 2 U 2516 2785
4 D 2710 3190 3 U 2580 2668
1 E 2 2760 3030 4 U 2565 2673
2 E 2790 3140
3 E 2860 3090 1 S 7 2012 2173
1 F 2 2940 3310 2 S 2011 2112
2 F 2910 3370 3 S 2200 2280
1 G 2 2920 3220 4 S 2190 2311
2 G 2970 3220
1 H 2 3030 3110 1 0 8 1229 1280
2 H 2970 2990 2 0 1132 1252
3 0 1188 1451
1 I 2 3000 3070 4 0 1429 1633
2 I 3050 3220
1 J 2 3070 3730 1 Q 9 2416 2808
2 Q 2562 2890
1 L 3 924 2451* 3 Q 2896 2907
2 L 895 708 4 Q 2750 2867
3L 866 942
1 M 3 820 1106 1 K 3 20, 534** 20, 622
2M 1024 1103 2K 20,885 21,762
3 K 20, 124 20, 943
* High value due to cleaning of distributors with HC1.
** Salt content of the influent increased by adding NaC 1.
-30-
-------
rate of 4. 5 gpm. The maximum sodium chloride content increase was
obtained with a cycle time of 30 mm. The difference between the 10
and 20 mm cycle times was not significant.
TABLE 11
SODIUM CHLORIDE CONTENT OF THE REGENERANT
INFLUENT AND EFFLUENT AT VARIOUS CYCLE TIMES
Cycle Cycle
Time, NaC1, ppm Time, NaC1, ppm
mm Inf Eff mm Inf Eff
10 1983 2135 40 2738 2849
2318 2363 2738 2884
2306 2451 2750 2890
2770 2972
20 2516 2785 2785 2925
2580 2668 2785 2984
2565 2673 2790 2890
2799 3177
30 2321 2790 2808 2907
2594 2878 2828 2880
2615 2837 2843 3024
2650 2790 2858 3010
2714 2937 3001 3060
2732 2948 3352 3732
2998 3179 3472 3674
3033 3136
3117 3146
Continuous Operation to Develop Treatment Cost Figures
In this phase of the study the time between the various unit operations,
e. g., desalination, regeneration and rinsing, was kept to a minimum.
Only 20 to 30 sec were required to pulse the resin between the runs.
The only significant interruption was the time needed for fresh brine
make -up.
In preparation for continuous operation, the regeneration chamber was
washed with a solution of hydrochloric acid to remove the organo-
-31-
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CA-i 4.5
2 4.5
3 4.0
4 4.5
5 3.5
CB-i 4.5
2 4.0
3 4.0
4 3.5
CC-i 4.5
2 4.0
3 4.0
4 3.5
CD-i 3.5
2 4.0
3 4.0
1761 50 642
50 900
30 784
30 670
30 690
1854 30 543
30 525
35 562
30 573
1878 30 465
30 453
30 470
30 452
1053 30 294
30 274
30 273
CG-i 7.5
2 7.0
3 7.5
CH-i 7.0
2 7.0
3 7.0
CI- 1 7.5
2 7.0
3 7.0
1526 30 652
30 623
30 578
1508 30 720
30 641
30 610
1740 30 1211
30 1030
35 860
1740 30 525
30 544
30 550
1547 30 1508
30 1110
30 878
Hardness in Product Water from Ion Exchange Treated Brines
The use of calcium hydroxide as a regenerant in the Aqua-Ion technology
causes this material to appear in the desalination product and results in
a hard water of limited reuse potential without additional treatment.
calcium compounds which had precipitated on the plastic beads holding
the resin above the distributor screen. This treatment resulted in re-
generant flow rates as high as 10 gpm. However, after a short time
the flow rate decreased due to plugging of the distributors by calcium
carbonate and organo-calcium compounds. The sodium chloride con-
tent of the influent brine during this continuous operational period was
1, 000 to 1, 900 ppm and the flow rate was varied from 3. 0 to 7. 5 gpm.
Table 12 tabulates the reduction in sodium chloride content of the
influent brine as the unit was operated continuously at different flow
rates.
TABLE 12
REDUCTION IN SALT CONTENT OF INFLUENT BRINE OBTAINED
DURING THE CONTINUOUS OPERATION OF THE UNIT
AT DIFFERENT FLOW RATES
Run NaC1,
No . ____ _____ ppm ____ ____ ___ ____
Flow
Rate,
gpm
Inf
NaC1,
ppm
Eff
V ol,
Flow
Inf
Eff
Rate,
NaCl,
Vol,
NaC1,
gpm
ppm
gal.
ppm
Run
No.
CE-i
2
3
CF-i
2
3
5. 0
5.0
5. 0
5.0
5.0
5.0
-32-
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TABLE 13
CALCIUM ION CONCENTRATION AND HARDNESS OF THE
INFLUENT AND EFFLUENT OF BOTH THE DESALINATION
AND REGENERATION PROCESSES
Sample Ca, Hardness as
Run Number Number* ppm CaCO , ppm
H-A 1 33 83
2 835 2083
3 713 1778
4 1091 2722
H-B 1 22 56
2 668 1667
3 701 1750
4 935 2334
H-C 1 47 120
2 800 2000
3 870 1940
4 990 2470
* Samples are the same as those in previous tables.
Calcium ion concentration was determined on a large number of the
usual set of four samples collected from individual runs under a
wide range of conditions. Table 13 tabulates the calcium ion concen-
tration and hardness as calcium carbonate for typical samples.
Extension of Ion Exchange Treatment to Brine from Other Commodities
The use of ion exchange treatment of dilute brines has promise for
reducing the saline pollution potential of liquid wastes from preserva-
tion of cabbage, cherries and pickles. New information was obtained
during this project on the composition of brines used to store cherries
and cucumbers. The final products of these storage systems were
Maraschino cherries and dill pickles. Arrangements to obtain brine
-33-
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TABLE 14
ANALYTICAL VALUES FOR BRINES
USED IN MARASCHINO CHERRY AND
DILL PICKLE PRODUCTION
Hardness
NaC 1, SS, * C.O.D., B.O.D., Ca, CaCO 3 ,
Product pH ppm ppm mg/liter mg/liter ppm ppm
Cherry 6.6 95 20 590 330 82 205
Cuc urn -
ber 3.6 39,900 95 3,936 2,480 589 1,470
* Determined by FWPCA Official Interior Methods for Chemical
Analysis of Waters, September, 1968
from storage of cabbage for sauerkraut were terminated when it was
learned that all of the brine is used as the liquid portion of the canned
sauerkraut or as canned sauerkraut juice. The results of analysis of
cherry and cucumber brines are tabulated in Table 14.
-34-
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SECTION V
DISCUSSION
Salt Removal
In general, the salt removal obtained was satisfactory. The results
demonstrated that desired product quality can be obtained at varying
levels of polar solute concentration when C. 0. D. and pH are relatively
constant. At 5, 000 ppm sodium chloride concentration, the salt content
of the product was higher than the target value of 175 ppm. The influent
salt level was not believed to be the cause of the higher level of sodium
chloride in the product water. Rather, the observed result could be
attributed to intermixing which took place through the resin bed and
caused displacement of the salt front. The intermixing problem was
encountered during several periods of operation of the ion exchange
unit. Near the end of the project a technique was found to minimize
intermixing in the resin bed. On completion of a regeneration cycle,
valve No. 3 and an additional outlet valve (just prior to valve No. 2 on
Figure 2) were opened. Compressed air was used to push out the re-
generant effluent and the water filling the wash chamber. In this way,
the contact between the regenerant and the final product at the top of
the Higgins Loop was avoided. The quality of the final product was
improved substantially when this procedure was applied. The salt
content was reduced from 1, 500 ppm in the influent to a range of 130
to 270 ppm in the desalination product. The unit was operated at 4 gpm
during this use of the revised procedure. It was unfortunate that more
time was not available to study all the variables examined and reported
above which were obtained under less than optimal operating conditions.
Conventional Regeneration
Slaked lime (Ca(OH) 2 ) performed successfully in regenerating spent
resin used to desalinate the olive processing brines. The recycling of
the regenerant effluent increased the sodium chloride content of the
regenerant. The long term trend of sodium chloride increase was ap-
parent from examination of data in Table 10, although the difference
in salt content in any pair of adjacent runs did not appear to be signifi-
cant (for example, Run No. lC and Run No. 3C). This was due to the
diluting effect of the wash water filling the void space of the resin.
-35-
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The void space can represent as much as 40 percent of the total volume
of the resin.
At high flow rates, when distributors tend to plug up, washing with acid
solution was required to open up the flow channels. The residues of
hydrochloric acid solution resulted in sudden increases in the chloride
ion readings for some effluent samples. The pre-liming and filtration
of the regenerant influent resulted in shorter regeneration times and
longer operational periods with fewer acid washings being required.
Within the time limit assigned to any given phase of the project, the
average increase in the sodium chloride concentration of the regenerant
solution was approximately 40 percent. There was no indication of a
leveling off of the rate of sodium chloride increase in the regenerant
effluent with increasing number of cycles.
The best regeneration cycle time was found to be 30 mm.
Carbonate Regeneration
One of the reasons that higher than expected sodium chloride levels were
observed in certain runs was because the resin was in a calcium carbo-
nate form rather than a calcium hydroxide form.
The equations for the reactions involved in carbonate regeneration are
the following:
(Cation) R Ca + 2 NaC1 = 2 RNa + CaCl
(Anion) R 2 C0 3 + CaC12 = 2 RCJ + CaCO 3
When the resin was partially or completely in the calcium carbonate form,
the salt removal was about 50 percent of that found for resin in the cal-
cium hydroxide form. The relatively low calcium content of the desali-
nated product effluent shown in Table 15 was the result of removing most
of the calcium as calcium carbonate. The sludge formed from the fil-
tration of the desalinated product water was found to contain substantial
amounts of calcium carbonate.
-36-
-------
TABLE 15
EFFECT OF THE CARBONATE REGENERATION ON
THE CALCIUM CONTENT OF THE PRODUCT WATER
Run Inf Eff*
No. NaC1 Ca CaCO 3 NaC1 Ca CaCO
CO3 A 1590 43 108 690 54 135
CO3 B 2850 12 29 1190 71 176
C03 C 2950 12 29 1290 47 118
CO3 D 1050 24 59 430 6 15
CO3 E 1150 24 59 570 12 29
CO3 F 1980 35 88 590 47 118
CO3 G 1650 33 81 590 43 108
* All results are in ppm.
The introduction of carbon dioxide into the ion exchange system is the
reason for the appearance of carbonate regeneration. The carbon
dioxide could have been introduced at the following points.
A. In the compressed air used to move the resin. If this
were the source, it could be corrected by passing the
air through an alkaline solution before compression.
B. In the lime used for the preparation of the regenerant
influent. Samples of lime were found to contain large
quantities of calcium carbonate. This could be corrected
by storing the lime in tightly closed containers.
C. In gas transfer through the cloth of uncovered filter hoses.
The plastic wrapping of the filter hose was occasionally
torn by strong winds; a combination of low temperatures
and rain wetting the hoses could promote the uptake of
atmospheric carbon dioxide.
The problem of carbonate regeneration could be eliminated by opera-
ting the unit at slower rates or by employing a larger desalination leg.
The second change would be the most economical way to correct for
the possibility of carbonate regeneration in a scaled-up production
unit.
-37-
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The filtration of the regenerant and the desalinated product was not
possible in a few runs due to the oxidative degradation of the cotton
filter hoses. The perforation of the Uni-Flow filters on these occasions
was the reason for the high suspended solids content of some samples
and for the very high values for calcium and suspended solids in cer-
tain of the regenerant suspensions. The perforation of filter hoses can
be forestalled by good maintenance; hoses should be replaced when they
show signs of deterioration.
The desired quality of the desalination product was obtained under most
operating conditions. Under certain conditions, the sodium chloride
content would be considered high. However, in some areas of California
the total dissolved solids content of municipal water supply range from
410 to 1,243 ppm. 6
The desalinated product is a hard water and its calcium content should
be reduced in order to increase reuse options.
The sodium chloride content of recycled regenerant solutions was in-
creased 40 percent over the influent brine level and evidence was
obtained that a ten-fold increase was possible. Stated in another way,
the sodium chloride present in the original olive processing water was
potentially concentrated in one-tenth of the original volume. At the
same time, a volume of desalinated water equal to the volume of the
treated olive processing brine was produced for possible reuse.
Examination of the data summarized in Table 14 indicates that the use
of ion exchange treatment of cherry processing brine would have little
utility. The very low sodium chloride level and moderately high calci-
urn level would not be changed significantly by the Aqua-Ion process.
The Aqua-Ion technology appears to be highly promising in the treat-
ment of liquid wastes from pickle production. The high values for
NaCl, B. 0. D., and hardness, along with low SS and pH, suggest that
pickle processing water could be treated effectively for recycle with
no concern from high calcium levels in the product water. The regen-
erant brine has good promise of use in storage systems for freshly
harvested cucumbers.
The cost of desalting 1, 000 gallons of olive processing water was esti-
mated at 26 cents (Table 16). The cost figures are based strictly on
the extrapolation of the pilot plant experimental data taken at a flow rate
-38-
-------
TABLE 16
COST ESTIMATE FOR 100, 000 GPD PLANT
$ 138,000
6, 624
2, 376
147, 000
22, 000
$ 169,000
FIXED CHARGES
Capital cost, 6% per year
Depreciation, 30 years
Insurance, 1% of plant
Sub -total
Administrative expenses 10%
Total fixed charges
OPERATING COST
Resin replacement in 4 years
Electricity, variable
Lime loss at $20/ton
Sub -total
Fixed charges
Waste purification cost
$ 10,000
5, 633
1,690
17, 323
1,732
$ 19,055
Per 1,000
$ 0.055
0.010
0.010
0. 075
0.190
$ 0.265
EQUIPMENT AND CONSTRUCTION COST
Column 7 ft diameter, with valves and
auxiliary equipment
Resin, 720 cu ft*
Site preparation
Sub -total
Erection cost and start-up 15%
Total plant cost
-39-
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TABLE 16 (Cont’d.)
POSSIBLE CREDIT Per 1,000 gal
Reclaimed water $ 0. 30
Reclaimed salt at $20/ton 0. 20
Sub-total 0.50
Possible profit $ 0. 24
of 4. 0 gpm, which corresponds to 5. 1 gpm/sq ft. No charge is
made for labor, since it is felt that food processor or a municipal
sewage treatment plant can easily assign the task to a paid employee.
This additional assignment would not take much time because the
treatment unit is fully automated and recording devices can be
placed remotely. The cost estimate is for a 100, 000 gpd plant at
2,500 ppm influent NaC1. The cost estima te applies to one set of
circumstances and is, therefore, subject to variation. Among
these circumstances are capital cost, local price and/or need for
reclaimed water, assessment of salt value, accounting principles,
etc.
-40-
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SECTION VI
ACKNOWLEDGMENTS
We acknowledge the considerable effort and expense contributed by
olive canning companies in collecting and delivering the olive
processing waters used in this project. We are especially grateful
to Dan Carter, Jud Carter, Orrin Scott and Peter Quijano of Bell-
Carter Olive Company and Noel Graves of California Canners and
Growers for their assistance in obtaining substantial volumes of
olive processing waters.
We are indebted to Kenneth A. Dostal of the Pacific Northwest Water
Laboratory of WQO-EPA for his many helpful suggestions and guid-
ance in the preparation of reports.
The following members of the staff of the NCA Berkeley Laboratory
made significant contributions to the obtaining and reporting of
results:
Nabil L. Yacoub, Edwin S. Doyle, Stuart Judd
Walter A. Mercer Jack W. Rails
Grant Director Project Director
-41-
-------
SECTION VU
REFERENCES
1. Powers, T. J., “Cucumber-Pickling Waste Water Treatment
and Disposal,” submitted to J. Water Pollution Control Fed .
(1966).
2. Etchells, J. L., Costilow, R. N., Anderson, T. E., and Bell,
T. A., “Pure Culture Fermentation of Brined Cucumbers,
Applied Microbiology 12 (6) 523-535 (1964).
3. Etchells, J.L. Berg, A.F., Kittel, I.D.,, Bell, T.A., and
Fleming, H. P., “Pure Culture Fermentation of Green Olives,”
Applied Microbiology 14 (6) 1027 - 41 (1966).
4. Vaughn, R. H., Martin, M. H., Stevenson, K. E., Johnson, M. C.,
and Crampton, V.M., ‘Salt-Free Storage of Olives and Other
Produce for Future Processing,” Food Tech . 23 (6), 832-4
(1969).
5. Popper, K., “Possible Uses of Uni-Flow Filter, “ Proceedings
of the First National Symposium on Food Processing Wastes ,
Portland, Oregon, pp. 362-376 (1970).
6. Anon. California Domestic Water Supplies , State of California,
Department of Public Health (1962).
-43-
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SECTION VIII
PATENTS AND PUBLICATIONS
The process technology used in the Aqua-Ion system is defined by
U.S. Patent 3,073,725 (issued in 1963 to K. Popper and V. Slamecka).
The Aqua-Ion Corporation has established the following policy posi-
tion with respect to utilization of their process technology for food
processing brine treatment.
ttOur patents are process patents and do not cover equipment; they
cover merely the manner in which to handle a given type of material.
Thus, we cannot collect equipment royalties; any royalties coming to
us will have to be derived from use. Any royalties we will ask for
will be based on savings the process will give the user beyond such
expenses as the user may have with waste disposal. Typically, one
may deal with a situation where the cannery pays $0. 10 sewerage
charges, $0. 10 a thousand gallons for water and where using our
system it will return $0. 17 worth of salt to process. According to
our preliminary calculations, the waste purification cost will be
$0. 17. Thus we see a saving of $0. 20, and we would like to nego-
tiate a reasonable royalty on that.
No publications have resulted from work done in the project to date.
The first public disclosure of the total project result was at the
Second National Food Processing Waste Symposium, Denver, Colo-
rado, March 23 - 26 1971.
-45-
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5 ! Or gan ,z ot,on
National Canners Association, Berkeley, California
Western Research Laboratory
Title
6 REDUCTION OF SALT CONTENT OF FOOD PROCESSING
LIQUID WASTE EFFLUENT
10 Atithor(.s)
Mercer, Walter A.
Ralls, JackW.
Project Designation
EPA, WQO Project 12060 DXL
21 Note
22! C on
2 3 j Descriptors (Starred First)
* Brine Desalination, Food Processing, Ion Exchange Treatment, Salt
Removal, Olive Processing
25 identifiers (Starred First)
—J
* Brine Treatment, Food Processing Brines
2 J Abstract Olive processing brines containing 0. 05 to 0.7 percent sodium chloride were
passed through a mixed bed of cation and anion exchange resins. The -effect of influent
composition on the composition of effluent from the ion exchange unit was investigated,
using a range of influent pH, salt content, and C.O.D. levels. The unit was operated at
sodium chloride levels of 500 to 7,000 ppm with random pH and C.O.D. levels. The
highest removal of sodium chloride (94 percent) was obtained at a level of 2,700 ppm so-
dium chloride in the influent. With pH and C .0. D. held constant, the salt content of the
influent was varied between 600 and 6, 000 ppm. The effluent sodium chloride content was
approximately 150 ppm at 600, 1,000 and 2,700 ppm and was 790 ppm at 6,000 ppm in-
fluent concentration.
The resins were regenerated using a solution of calcium hydroxide. To estab-
lish the maximum salt concentration attainable in the regenerant effluent, the regenerant
was repeatedly recycled through the resin bed. The sodium chloride content of recycled
regenerant solutions was increased 40 percent over the influent brine level, and evidence
was obtained that at least a ten-fold increase was possible.
The cost of desalination of dilute food processing brines by this ion-exchange
treatment was estimated at $0.26 per 1,000 gallons of influent. (Ralls - NCA)
R ‘ 2 IREv JULY 15691
.RSI C
SEND TO WATER RESOURCES SCIENTIFIC IN FORMA lION CENTER
U S. DEPARTMENT OF THE INTERIOR
WASHINGTON. 0 C 20240
A , -s,IU ,I !Vambl’r 1 SIibJct Fr!d&. Grcip
05D
SELECTED WATER RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
Ahstractor Institution
Jack W. Ralls National Canners Association
* G O: I969—359 33S
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