WATER  POLLUTION CONTROL RESEARCH SERIES
1704OEFQO2/71
         REVERSE OSMOSIS
  RENOVATION  OF  PRIMARY SEWAGE
 U.S.  ENVIRONMENTAL PROTECTION AGENCY

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          WATER POLLUTION CONTROL RESEARCa SERIES

The Water Pollution Control Research. Series describes the
results and progress in the control and abatement of pollu-
tion of our Nation's waters.  They provide a central source
of information on the research, development, and demon-
stration activities of the Environmental Protection Agency
through inhouse research and grants and contracts with
Federal, State, and local agencies, research institutions,
and industrial organizations.

Inquiries pertaining to the Water Pollution Control Research
Reports should be directed to the Head, Publications Branch,
Research Information Division, R&M, Environmental Protection
Agency, Washington, D.C. 20460.

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            REVERSE 03OSIS RENOVATION OF PRIMARY SEWAGE
                      Envirogenics Conpany
                          A  Division  of
                   Aeroj et-General Corporat ion
                   El Monte, California  9173^
                             for the

                ENVIRONMENTAL PROTECTION AGENCY
                        Project #170^0 EFQ
                        Contract #14-12-885
                           February  1971
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 - Price 65 cents

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               EPA Review Notice
This report has been reviewed by the Environmental
Protection Agency, and approved for publication.
Approval 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
constitution endorsement or recommendation for
use.
                     ii

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                           ABS TRAC T
A 4-month laboratory bench-scale program was conducted at the City
of Corona, California, Water Reclamation Plant to investigate the fea-
sibility of renovating primary sewage treatment plant effluent by the
reverse osmosis process.  Results were obtained on the processing of
primary effluent under a variety of operating conditions.  Secondary
effluent was also processed for comparison.

Maintenance of high feed water  axial velocity was the only method of
those considered that  provided an acceptable product water flux decline
with primary effluent.  At an axial velocity of 12. 9 ft/sec, the perfor-
mance with primary effluent was comparable to that observed with
secondary effluent at 2. 58 ft/sec.  Axial velocities of 2. 58 and 6. 45
ft/sec were insufficient to prevent gross membrane fouling with pri-
mary effluent.

High indigenous calcium and sulfate concentrations in the sewage
resulted in mild calcium sulfate precipitation and unacceptable per-
formance with alum-treated,  sand-filtered primary effluent at a 2%
product water recovery ratio.  At  more practical recoveries in excess
of 50%, both secondary effluent and alum-treated, sand-filtered pri-
mary effluent experienced severe membrane fouling by calcium sulfate
deposition.

Sizable restorations in product  water flux were achieved by an occa-
sional cleansing with an enzyme-active laundry presoak formulation.
Short-term depressurization  of the reverse osmosis system for 15
minutes also restored product water flux, but to a lesser extent.

Rejections of major pollutants were high and improved with increasing
feed water axial velocity.   Values  for primary effluent at the lowest
axial velocity of 2. 58  ft/sec averaged 93. 7% for total dissolved solids
as measured by electrical conductivity, 94. 2% for chemical oxygen
demand, 84. 7% for ammonium nitrogen,  and 100% for turbidity.
Corresponding average rejections  at an axial velocity of 12.9 ft/sec
were 98.0% for total dissolved  solids, 97. 8% for chemical oxygen
demand, and 100% for turbidity.

This report was submitted in fulfillment of Project Number 17040 EFQ,
Contract 14-12-885, under the  sponsorship of the Water Quality Office,
Environmental Protection Agency.

Key Words: *Demineralization, ^Reverse osmosis, *Sewage treat-
            ment, *Water reuse,  Membrane processes, organics
            removal, solids removal.
                                111

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                         CONTENTS

Section                                                      Page


  I.      CONCLUSIONS                                        1

  II.     INTRODUCTION                                      , 3

  tU.    PROCEDURES                                        5

               Test Apparatus                                  5

               Feed Waters                                     7

               Operating Conditions                            11

               Measurements                                  12

  IV.    LABORATORY RESULTS                             15

               Primary Effluent                               17

               Alum-treated, Sand-filtered Primary
               Effluent                                        20

               Secondary Effluent                              24

  V.     DISCUSSION                                         31

  VL    ACKNOWLEDGEMENTS                              37

  VII.   REFERENCES                                       39

  VIII.  GLOSSARY                                           41

  IX.    APPENDICES                                        43

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                           FIGURES

                                                            Page


1.       Schematic Flow Sheets of Reverse Osmosis             6
            Test Apparatus

2.       Reverse Osmosis Test Apparatus                       8

3.       Laboratory Trailer and Primary Effluent               9
            Clarification Unit

4.       Reverse Osmosis Performance with Zimmite 190-     18
            treated Primary Effluent, Nonrecirculating
            System at 700 psig

5.       Effect of Feed Water Velocity on Product Water        19
            Flux with Primary Effluent  Feed,  Non-
            recirculating System

6.       Reverse Osmosis Performance with Alum-treated     22
            Sand-filtered Primary Effluent, Nonrecircula-
            ting System at 700 psig

7.       Reverse Osmosis Performance with Concentrated      25
            Alum-treated, Sand Filtered Primary Effluent,
            Recirculating System at  700 psig

8.       Reverse Osmosis Performance with Secondary         26
            Effluent, Nonrecirculating System

9.       Comparison Between Product Water Flux and          28
            Secondary Effluent Quality

10.     Reverse Osmosis Performance with Concentrated      29
            Secondary Effluent,  Recirculating System at
            700 psig
                              VI

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                            TABLES


Table                                                         Page


  1.      Wastewater Characteristics,  City of Corona Water     10
              Reclamation Plant

  2.      Average Feed Water Constituent Concentrations        16

  3.      Average Wastewater Constituent Rejections and        21
              Product Water Quality
                               VII

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                            SECTION I

                           CONCLUSIONS


A number of findings and conclusions are presented, based on the con-
duct of a 4-month laboratory bench-scale investigation at the City of
Corona Water Reclamation Plant to determine the feasibility of treating
primary effluent by the reverse osmosis process.

For primary effluent, only the  highest of three feed water axial velo-
cities used, namely 12.9 ft/sec corresponding to a nominal Reynolds
number of 54,000, provided acceptable product water flux performance
at low recovery levels and at a pH of 6. 0.  After the first day of ope-
ration, the product water  declined slowly from about 23 to 16 gal. /
(sq ft)(day) over  14 days.  Under the same feed water conditions, axial
velocities of 2. 58 and 6.45 ft/sec, corresponding to nominal Reynolds
numbers of 10,800 and 27,000, respectively,  resulted in excessive
product water flux declines to less than 3 gal. /(sq ft)(day) in just two
and seven days,  respectively.

Product water flux performance with primary effluent at the  12. 9 ft/sec
axial velocity was comparable to that obtained with secondary effluent
at the lower axial velocity of 2. 58 ft/sec.

Pretreatment methods employed in this program were of little benefit
in preventing rapid product water flux declines with primary effluent
at an axial velocity of 2. 58 ft/sec.  At low product water recoveries,
pH adjustment of the high-calcium and high-sulfate sewage  with hydro-
chloric acid reduced the occurrence of calcium sulfate precipitation
and deposition that occurred with sulfuric acid addition, but neither
acid substantially reduced the product water flux decline.  Addition of
the anionic flocculating polyelectrolyte Zimmite 190 was ineffective in
preventing membrane fouling.  Product water fluxes declined from more
than 20 to 2. 5 gal. /(sq ft)(day)  in just four days.

Although removal of suspended and finely dispersed solids by alum
addition, flocculation, sedimentation,  and sand filtration partially
reduced product  water flux declines with primary effluent,  the re-
verse osmosis performance remained poor.  When using the alum-
treated primary  effluent at a pH of 5. 3 effected with sulfuric acid
addition, a feed water axial velocity of 2. 58 ft/sec,  and at a product
water recovery ratio of 2%, the product water flux dropped from 40
to 4 gal. /(sq ft)(day) in six days. Maximum performance was obtained
when the pH was  adjusted  to 5.  3 with hydrochloric acid; the average
product water flux diminished from 30 to 8 gal. /(sq ft)(day)  in 24 days.

Both secondary effluent and alum-treated,  sand-filtered primary ef-
fluent produced rapid product water flux declines at an axial velocity
of 2. 58 ft/sec and at concentrations corresponding to product water

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 recovery ratios as low as 50%.  This was attributed primarily to the
 precipitation of calcium salts from the wastewaters, which contained
 high indigenous concentrations of calcium and sulfate.

 In the absence of continuous chlorination of the feed water streams,
 biological growth occurred that severely depressed the product water
 flux when the feed water pH was that of normal sewage, or 6. 8 in this
 study,  and not at the more acidic conditions of pH values of 5. 3  or  6. 0.
 Chlorination of feed waters therefore would appear  to be a requirement
 only if feed waters were not acidified to pH levels below about 6.

 High removals of major pollutants contained in municipal wastewaters
 were accomplished by the reverse osmosis process.  Rejections were
 dependent upon feed water quality and  operating conditions,  with ave-
 rage overall removals ranging from 84 to 98% for total dissolved solids
 as measured.by electrical conductivity,  100% for suspended and dis-
 persed solids as measured by turbidity, from 85  to 98% for  oxidizable
 organics as  measured by chemical oxygen demand,  and from 88 to  95%
 for ammonium nitrogen.

 Wastewater  constituent rejections from primary effluent improved  as
 feed water axial velocities increased,  rising from a total dissolved
 solids rejection of 93. 7% at an axial velocity of 2. 58 ft/sec to 98. 0%
 at 12. 9 ft/sec.   This  is a consequence of a diminished liquid boundary
 layer thickness, which creates a smaller salt concentration directly
 at the membrane surface.  Thus operation of the  reverse osmosis
 process at high feed water axial velocities will result in an increased
 tolerance to dissolved solids concentrations  in the feed water  stream
 without attendant decrease in product water quality.

 Daily system depressurization for a period of 15  minutes proved bene-
 ficial to maintenance  of product water fluxes.  The  degree of flux re-
. covery immediately following depressurization was  a function of the
 rate of product water flux decline.  Benefits ranged from  1.1% for
 primary effluent at an axial velocity of 12. 5 ft/sec where the general
 flux decline  was relatively small,  to 99. 4% for primary effluent at  an
 axial velocity of 2. 58 ft/sec where the flux decline was reasonably
 large.

 Unexplained rises and falls in product water fluxes  were observed and
 suggest that certain sewage constituents that were not uniquely charac-
 terized by the feed water turbidity and chemical oxygen demand  affect
 membrane performance.

 Soaking of a severely fouled membrane in an enzyme-active laundry
 presoak formulation was often found to be beneficial to the restoration
 of product water flux.

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                             SECTION II

                           INTRODUCTION
A major remaining obstacle to municipal wastewater treatment by
reverse osmosis systems is the relatively rapid decrease in the  capa-
city of the membrane to transport product water.  This decline in
production rate is due to two factors: intrinsic compaction or re-
orientation of the membrane structure,  and fouling by dissolved and
solid  substances contained in the feedwater.  In the treatment of
municipal wastewaters, the  magnitude of the flux decline produced
by intrinsic properties of the membrane has proven to be negligible
in comparison to that associated with deposits formed on the mem-
brane surface or other interactions between wastewater constituents
and the membrane surface.

Whereas the magnitudes of product water flux after a given operating
time may be different for various types  of municipal wastewaters, re-
flecting the  quality or amount of pretreatment afforded it, the rates of
flux decline after several weeks of operation with raw sewage, pri-
mary effluent, and secondary effluent were  observed to be quite
similar (Ref. 1).  These similar decline rates would appear to indi-
cate that the fouling  mechanism likewise is the same for these waste-
waters, and the means of inhibiting or eliminating flux decline for one
wastewater  should apply equally to the others.  Therefore, renovation
of primary sewage by reverse osmosis  was indicated to reduce the de-
gree of pretreatment to a minimum.  Raw sewage was excluded from
consideration due to its abrasive character.

To substantiate earlier findings under more realistic conditions, a
4-month laboratory-scale,  field-test program was conducted.  Tests
were  performed at the  sewage treatment facility of the City of Corona,
California,  to provide a continuous  supply of fresh primary and secon-
dary sewage to the reverse osmosis units,  which provided a small
membrane surface area of less than 2. 4 sq  ft and which were operated
in either a nonrecirculating  or recirculating mode.

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                            SECTION III

                           PROCEDURES
This program was conducted at the City of Corona "Water Reclamation
plant, which employs the activated sludge process presently operating
at one-half its design flow of 5. 5 mgd.  The facility consists of pre-
liminary screening, primary sedimentation,  mixed liquor  aeration,
secondary sedimentation,  and anaerobic  sludge digestion,  with super-
natant return to the primary sedimentation tank.

TEST APPARATUS

The reverse osmosis membranes used in this program were cast from
a cellulose acetate-cellulose triacetate blend with a degree of acetyl
substitution of 2. 63.  Initial osmotic properties of individual membranes
observed with a one percent pure sodium chloride solution at 700  psig
ranged from 22. 3 to 45. 0 gal. /(sq ft)(day) for product water flux and
from 80. 5 to 95. 4% for salt rejection. These fluxes are equivalent to
membrane coefficients of from  22. 1  to 44. 5 /ig/(sq cm)(sec)(atm),
respectively. The average initial water  flux was 33. 6 gal. /(sq ft)(day)
and the average initial  sodium chloride rejection was 87. 1%.  Detailed
data on initial osmotic properties of the membranes are presented in
Appendix A.

The membranes were cast into  polyester sleeves that were subsequently
inserted into tubular braided fiberglass-resin shells with a 0. 56-in.
finished internal diameter.  The membraned tubes were fitted  with
bonded-on,  or in later versions molded-on, end fittings and inserted
into polycarbonate return bends supported by a steel frame.

Four  separate reverse osmosis test apparatus were used.   Three con-
sisted of four 52-in. long reverse osmosis tubes  placed in series flow
configuration that were operated without  recycling of the wastewater
reject stream through the unit.   These units provided a total effective
membrane area of 2. 4  sq ft.  The fourth test apparatus contained two
52-in. long reverse osmosis tubes (1.2 sq ft total)  in series flow  con-
figuration that was operated with  recirculation of the reject stream.
Schematic flow sheets of the test  apparatus are shown in Figure 1.

High-pressure pump capacities for the four units differed.  Two of the
nonrecirculating systems were  equipped  with progressing  cavity pumps
of 7-gpm  rated capacity each,  whereas the third  was supplied from two
diaphragm pumps of 1 -gpm rated capacity placed in parallel flow  con-
figuration to deliver a total of 2 gpm.  The recirculating reverse
osmosis unit was likewise equipped with  two parallel-mounted  dia-
phragm pumps of 1 -gpm rated capacity that supplied a total of  2 gpm.

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REMOTE
FEED

r f~ t ""
C / A
— I~N
l)~
ACID
FEED
HIGH
PRESSURE
MIXING pUMp
CHAMBER KUWIK

H 	 1 t ^ J (O—-

- -h ^
|_j 0
pH *
SENSOR WASTE



g nswosiK
^0

T ^ T
PRODUCT
        Nonrecirculating System
 AC|D       MIXING
-ACID       CHAMBER
                                                     REVERSE
                                                     OSMOSIS
                                                     TUBES
                     HIGH
                     PRESSURE
                     PUMPS
          Recirculating System
  Figure 1.  SCHEMATIC FLOW SHEETS OF
     REVERSE OSMOSIS TEST APPARATUS

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At the start of the program on 22 July 1970, all tubes were placed in
a vertical attitude to facilitate installation and product water collection
from individual tubes.  Tube failures were experienced that could be
attributed to the occurrence of negative pressures inside the membrane
sleeve at the top end of the tube during regular depressurization opera-
tions.  On 9 September 1970 all tubes were changed to a horizontal atti-
tude to eliminate this condition.  Both the vertical and horizontal ar-
rangements of a 4-tube nonrecirculating reverse osmosis test apparatus
are shown in Figure 2.

FEED WATERS

Sewage was supplied to the reverse osmosis test facilities continuously
by means of remote pumps located in the overflow channels  of the pri-
mary and secondary sedimentation tanks,  and thus represented the
normal diurnal variations  in quality encountered at sewage treatment
plants.  In addition, alum-treated, sand-filtered primary sewage was
continuously produced by a complete packaged clarification plant rated
at 3. 8 gpm.  The plant,  pictures in Figure 3  in front of the laboratory
trailer, consisted of a chemical solution tank and feeder,  rapid mixer,
sedimentation basin,  pressure sand filter, and clearwell.

"Wastewater analyses  provided by the City of Corona Water Reclamation
Plant on 24-hour composite samples collected during the test program
period are presented in  Table  1.  Influent raw sewage quality appeared
to remain generally unchanged over the study period, with the excep-
tions of several isolated high concentrations of chemical oxygen demand
and suspended solids  and a slightly increasing trend of biochemical oxy-
gen demand concentration.  The sewage is high in total  hardness  and
total dissolved solids, which can be attributed to the water supply in
the area.

Average BOD removal by the primary treatment portion of the plant
during the program was 48. 2% if the results  reported for  the period
14 through 29 September 1970 are discarded.  For the comparable
period the average suspended solids removal was 66. 3% in the pri-
mary process.

During the last half of September the Water Reclamation Plant was
experiencing one of the three episodes of operational difficulties en-
countered during the program.  The other two episodes  occurred at
the end of August and middle of October between the  reported dates
for wastewater characteristics, so that they are not  in evidence in
Table 1.  These,upsets were characterized by excessive foaming in
the aeration tariks and rising sludge in the secondary sedimentation
basins.  During the September occurrence, the average BOD and
suspended solids removals by the primary process were reduced to
26.4 and 59.2%,  respectively.

From the data reported  in Table 1, the overall BOD  removal efficiency
of the Water Reclamation Plant during the period of this program was
90. 1 percent.

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                  Vertical Attitude
                 Horizontal Attitude
Figure 2.  REVERSE OSMOSIS TEST APPARATUS

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-
                       SEDIMENTATION BASIN
             Figure 3.  LABORATORY TRAILER AND PRIMARY EFFLUENT CLARIFICATION UNIT

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                                                                       Table 1
                                 WASTEWATER CHARACTERISTICS,  CITY OF CORONA WATER RECLAMATION PLANT
                                                                       (mg/1)
                                                                                     Date

Plant Influent (Raw Sewage)
Suspended Solids
BOD
Total COD
Primary Sewage
Suspended Solids
BOD
Plant Effluent (Secondary Sewage)
Suspended Solids
BOD
Total COD
Electrical Conductivity*
Total Dissolved Solids
Chloride
Sulfate
Hardness, as CaCO,
7-21

228
198
512

85
105

-
32
32
1700
1025
265
170
342
7-23
i
253
173
492

97
90

-
25
48
1650
1019
250
195
308
7-30

250
234
524

73
120

-
32
63
1650
991
255
170
325
8-4

-
-
404

-
113

-
11
48
1700
1033
250
195
325
8-5 8-11 8-18 8-25

222 231 240 207
255 240 236
445

87 90 98 80
128 115 - 146

-
20
44
1675
1033
250
- 180 -
308
9-9 9-14

337 275
275 220
-

99 101
144 153

-
-
-
1650
-
245
165
325
9-17

200
198
-

80
147

-
-
-
1600
999
250
155
342
9-24 9-29

237 213
192 270
404

98- 96
138 213

-
7
37
1650
1013
240
175
325
10-6

426
318
756

91
159

-
-
50
1650
970
235
153
308
10-8 10-20

244 275
288 268
449

80 71
173 135

-
19
47
1675
-
335
235
342
10-25

253
274
447

83
-

-
20
43
- .
-
-
-
-
*/imho8/cm at 25°C

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OPERATING CONDITIONS

All tests were conducted on a continuous basis, 24 hours a day, 7 days
a week with a routine daily depressurization of about 15 minutes.  This
daily shutdown was provided to assist in the maintenance of product
water flux through the membrane and to allow scheduled cleaning of
system  components such as electrodes in the pH controllers.

Tests were  run at 700-psig operating pressure with all depressuriza-
tion going to zero psig in no  less time than 20 seconds. Feed water
flow rate was 2 gpm (10,800 calculated nominal Reynolds number,
2. 58 ft/sec/axial velocity) except for two instances with primary sewage
feed where the flow rate was 5 gpm (27,000 Reynolds number,  6.45
ft/sec axial velocity) and 10  gpm (54,000 Reynolds number, 12.9
ft/sec axial velocity).

Product water recovery ratios except for the first few  hours of opera-
tion when very high product water fluxes occurred with virgin mem-
branes, were less than 2% for the nonrecirculating systems.  The
recirculating system was operated at several product water recovery
ratios ranging from 50 to 90%.  Upon attaining  the desired recovery
ratio, as determined volumetric ally from the feed and  product waters,
the electrical conductivity was recorded and thereafter maintained at
that level throughout .the test.  The  recirculating  system was fed by
gravity from a storage container replenished on a daily basis.  Initial
concentrations of all feed waters were effected with the same membrane
utilized for  the conduct of the test at the elevated recovery ratio.

Chemical addition prior to reverse  osmosis processing was accom-
plished in the low-pressure sewage feed line.   For pH  adjustment,
controllers  intermittently injected predetermined amounts  of acid
into the feed line to produce  the necessary pH change.   The sewage
proceeded to an expansion-mixing chamber and then to the  pH sensing
electrodes.   An excess amount of acid was countered by an automatic
acid feed shutoff that was restarted when pH rose above a preset level.
A pH of 5. 3 was the lowest stable value  that could be maintained with
the equipment used.

The addition of other chemicals to prevent deposition of wastewater
substances on the membrane was accomplished upstream of the ex-
pansion-mixing chamber.  Zimmite 190, an anionic polyelectrolytic
flocculating agent, was used on the  basis of its successful application
in a previous laboratory program (Ref.  1).  The addition of chlorine,
while not standard practice,  was necessitated at times to prevent bio-
logical growth on the membrane, surfaces.  An enzyme-active laundry
presoak formulation used as a membrane cleanser was injected under
low pressure into the depressurized system immediately upstream of
the reverse osmosis tubes and allowed to soak for 10 minutes.   The
manufacturer's recommended dosage for stain removal of 2 tbsp/gal.
of water was used at ambient temperature and pressure.  A 2- to 5-gpm
                                 11

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tap water flush for several minutes followed the soaking,  removing all
loose particulate matter and the bulk of the presoak formulation from
the reverse osmosis tubes.

Chemical-physical removal of suspended matter from primary effluent
was accomplished in an alum clarification plant,  especially built to
handle the low flows encountered in this project.  Primary effluent was
fed at 3. 8 gpm into a rapid-mix pipe where  300 mg/1 of commercial
grade aluminum sulfate was  added to the main stream. Optimum dos-
age was established and frequently checked by the standard jar test
procedures.   From the rapid mix pipe,  the flow proceeded to a slow-
mix chamber with a retention time of 28 minutes.   Ports  in the bottom
of the chamber, which was suspended in an 800-gal. circular sedimen-
tation basin, discharged flocculated solids and the main liquid stream
to a 3. 5-hour gravity separator with a surface loading rate of 400  gal. /
(sq ft)(day).  Clarified  effluent from this tank proceeded to a pressurized
sand  filter and thence to a 375-gal. clear well, which supplied the 2-gpm
flow required by the reverse osmosis test apparatus and  sufficient stor-
age to backwash the filter every six hours.

MEASUREMEN TS

Product water flux was determined for individual tubes by collecting a
fixed volume over a known time period.  Reported values were deter-
mined at 1300 hours daily. Electrical conductivity, pH,  turbidity,
chemical oxygen demand,  and ammonium concentrations  of feed and
product streams were monitored and analyzed in accordance with pro-
cedures outlined in the Twelfth Edition of Standard Methods for the
Examination of Water and Wastewaters  (Ref. 2).

Electrical conductivity was measured on batch samples with a conduc-
tivity bridge and a 1-ml immersion probe.

A continuous  record of the pH in the nonrecirculating systems was ob-
tained.   The pH in the recirculating system was measured five times
daily over an 8-hour period, with a meter using a glass electrode  and
calomel reference cell.

Turbidity of the feed water streams was measured daily by an elec-
tronic turbidimeter, Hach Model 1860A. Product water streams were
intermittently measured but were found to be below the range of accur-
ate sensitivity of the instrument; i. e. , less than 0. 2 Jackson turbidity
units  (jtu).

Total chemical oxygen  demand  concentrations were determined thrice
weekly by potassium dichromate-sulfuric acid digestion for two hours
and ferrous ammonium sulfate  titration to the ferrous indicator end-
point.  Chloride present in the  sample was complexed with mercuric
sulfate.
                                 12

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Ammonium,  in weekly samples, was  distilled from Kjeldahl flasks,
collected in boric acid solution, and quantified colorimetrically at
476-m/x. wavelength in a spectrophotometer following  Nesslerization.

In addition to these routine analyses,  solids samples from membrane
surfaces and liquid stream samples were analyzed occasionally for
calcium,  total phosphorus, sulfate, carbonate, and total volatile mat-
ter by an independent laboratory in accordance with Twelfth Edition of
Standard Methods (Ref.  2).

Grab samples for chemical oxygen demand and ammonium analyses
were collected at 1100 hours.   Other  liquid analyses  were performed
on grab samples taken at 1300 hours for the product water flux deter-
mination.
                                  13

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                            SECTION IV

                      LABORATORY RESULTS
Performance of the reverse osmosis process is characterized by the
product water flux and wastewater constituent rejections, which are
dependent upon a combination of factors including membrane type,
feed water quality, operating pressure, product water recovery ratio,
feed water velocity, and type and dosage of additives.  The results de-
scribed herein reflect these influences, which are presented as they
were investigated within particular feed water groupings.

Average feed water qualities directly affecting membrane performance
are presented in Table 2.  Samples for analysis were taken just prior
to the liquid stream entering the reverse osmosis tubes; therefore,
while the nonrecirculating systems may have been operating at a 2%
product water recovery ratio condition, the feed waters were at a zero
recovery condition and are so labeled.  Inspection "of Table 2 will re-
veal that for alum-treated, sand-filtered primary sewage and  secon-
dary sewage,  feed water constituent concentrations decrease,  instead
of increase, or are not as high as would be expected  at the higher re-
covery ratios  of 80 and 90%.  This is attributed in part to the method
of volumetrically establishing product water recovery ratio conditions,
wherein a single batch sample is concentrated and future electrical
conductivity values established at that time.   The single sample of
feed water used in the initial concentration may have differed suffi-
ciently in composition from that of subsequent samples to produce
this  effect.  Also decreasing turbidities and  total  organics with in-
creasing recovery ratio may be caused by agglomeration of particulates
and oxidation of organics in the strongly agitated, recirculating system
used for high recovery ratio test conditions.  Electrical conductivity
is not so easily influenced by these conditions on the  other hand, due
to the fact that its  level is artifically maintained at a constant  value.

Some initial product water fluxes will be depicted in  subsequent illus-
trations well in excess of those recorded in Appendix A for initial
membrane properties. This is due in part to the  fact that all new
membranes during the first few minutes of pressurization exhibit high
transient fluxes which are not measured during  the production line
quality-control test. When the high transient fluxes occurred  near a
scheduled sampling period,  they were recorded for that period.  Fur-
thermore,  the standard saline solution of 10,000 mg/1  sodium chloride
used in the  quality-control tests exerts a greater  osmotic pressure
than does sewage with approximately 1, 200 mg/1 of total dissolved
salts, which results in a naturally higher product water flux with sew-
age feed at  any given operating pressure.
                                  15

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                                               Table 2

                    AVERAGE FEED WATER CONSTITUENT CONCENTRATIONS
       Feed Water
Primary Effluent

Alum-treated, Sand-
  filtered Primary Effluent
Secondary Effluent
ecov«
0
0
65
90
0
50
70
80
Temp-
;ry, erature,
°C
32
34
35
36
31
32
33
33
ECa
1969
2182
4875
9400
1872
3381
4133
3856
Tur-
bidity,
Jtu
61
3.8
4.2
4.8
5.6
10.6
10.9
8.8
Total
COD,
mg/1
230
80
202
127
67
211
197
147
NH4-
mg/
4.0
3.6
7.3
-
2.7
10.5
-
M
Constituent

       Total
         P,
Ca,
       18.3°

        0. 06*
 98l
108
SO
                                                                                                    4'
                                                                                  mg/1  mg/1    mg/1
 360
 Electrical Conductivity, /umhos/cm at 25°C
 Single sample preceding acidification

-------
PRIMARY EFFLUENT

Primary effluent feed water was relatively unchanged,  except for pH
adjustment and addition of a solids deposition inhibitor,  and was tested
in the nonrecirculating apparatus.   The test was started with sulfuric
acid for adjustment of the pH to 6. 0 — a level shown by previous expe-
rience to  be optimum for maximum effectiveness of the  Zimmite 190
additive.  Figure 4 shows the ineffectiveness of both the Zimmite 190
and the pH adjustment in preventing severe flux decline during the first
50 days of operation at axial velocities of 2. 58 or 6.45 ft/sec.   Fre-
quent enzymatic cleansings were necessary because of the very rapid
drops in product water flux.  No improvement  in results was noted
despite the use of various dosages of the Zimmite additive.  An analy-
sis of membrane deposits taken from this system operated at a pH of
6. 0 maintained with sulfuric acid and at 2 mg/1 Zimmite 190 revealed
3. 55% phosphorus, 2.46% calcium,  5. 44% sulfate,  73. 78% volatile
matter, and 14. 77% unidentified material.  The relatively high  abun-
dance of calcium,  sulfate, and phosphorus indicated that salt preci-
pitates may be significant factors in membrane fouling.

Subsequent tests conducted with hydrochloric acid at a pH of 5. 3 in
order to reduce calcium  sulfate and phosphate  deposition did not re-
sult in improved product water flux. Analysis of membrane deposits
from a test with hydrochloric acid and Zimmite 190 indicated 3. 23%
phosphorus, 0. 94% calcium, 0. 11% sulfate, 73. 67% volatile matter,
and 23% unidentified material.  Discontinuation of sulfuric acid addition
apparently prevented major calcium sulfate deposition but did not pre-
vent product water flux decline.

Because the various pretreatments were unsuccessful in preventing
membrane fouling, a set of tests was initiated  to  measure the effects
of varying the feed water axial velocity from the standard of 2. 58
ft/sec (10,800 Reynolds number,  2-gpm feed rate).  The first test
with a feed water axial velocity of 6. 45 ft/sec (27, 000 Reynolds num-
ber, 5-gpm feed rate) did not produce  an acceptable product water
flux but did result in a substantially reduced flux decline as shown in
Figure 5.

A subsequent test with feed water axial velocity of 12. 9 ft/sec (54, 000
Reynolds  number,  10-gpm feed rate) resulted in a dramatic improve-
ment in membrane performance.  The  test was marred by tubular
structure  failures and terminated prematurely by pumping equipment
failures but nonetheless presented adequate data showing working
solutions  to the  membrane fouling problem indicated by Figures 4
and 5. In the  one tube lasting the entire test period, the flux declined
from 27 to 14  gal. /(sq ft)(day) over a period of 15 days and was not
very unlike declines obtained with secondary sewage.

Periodic depressurization of the reverse  osmosis system did result
in improved product water flux when measured immediately upon re-
starting operation.  Immediate flux recoveries for axial velocities of
2.58, 6.45 and 12.9 ft/sec  were 99.4,  3.4, and 1.1%,  respectively.
                                 17

-------
                                       Recovery. %
                                          •   PH
- HCI -*-H2SO4-«-  HCI
                                      Feed Velocity,
          6.4b-»— 2.58	»-
                    PUMP FAILURE

                         I      I
  1  TUBE REPLACEMENT

      I       I      I
 2  ENZYMATIC CLEANSING

I      I      I
                                     30     35    40    45
                                    OPERATING TIME, days
Figure 4.   REVERSE OSMOSIS PERFORMANCE WITH ZIMMITE 190-TREATED
            PRIMARY EFFLUENT, NONRECIRCULATING SYSTEM AT 700 psig
                                                 70
    18

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1      I       I
 700psig
 6.0 pH (H2S04)
                            FEED VELOCITY 12.9 ft/sec
                            REYNOLDS NO.   54,000
 FEED VELOCITY 2.58 ft/sec
 REYNOLDS NO.   10,800
                                   FEED VELOCITY 6.45 ft/sec
                                   REYNOLDS NO.  27,000
                                   50

                                   40

                                   30
                                                                                         20  «
                                                                                         10
                                                                                         9
                                                                                         8
                                                                                         7
                                                                                         6
                                                                                         5
                                       Z
                                       u.
                                       Ul
                                       8
                                       UJ
                                                                                             oc
                                                                                             CO
                                                                                             UJ
                                  7      89
                             OPERATING TIME, days
10
11
12
13
14
15

-------
Table 3, which presents wastewater constituent rejections for the
various principal test conditions, indicates that the constituent rejec-
tions for dissolved solids (EC), chemical oxygen demand (COD),  and
ammonium (NH4 ) substantially improved with increasing feed water
axial velocity.  The change in the dissolved solids rejection alone was
from 93. 7% at 2. 58 ft/sec to 98. 0% at 12. 9 ft/sec.  No evidence of
unusual membrane deterioration was observed during this test period.
Tube replacements were necessitated almost solely by structural sup-
port failures.

Daily product water flux and pollutant rejection data are tabulated in
Appendix B.

ALUM-TREATED, SAND-FILTERED PRIMARY EFFLUENT

Alum-treated, sand-filtered primary effluent is characterized by
having a lower suspended and dispersed solids content than primary
effluent and a higher dissolved organic chemical content than secon-
dary effluent.  It was anticipated that this type of feed water would
eliminate membrane fouling by finely dispersed solids and provide
long-term, low  flux decline  performance.  Figure 6 demonstrates,
however, that for the longest duration run of 24 days the product water
flux declined from 20 (ignoring the much higher transient flux) to 8  gal. /
(sq ft)(day) with alum-treated, sand-filtered primary effluent  in the
nonrecirculating apparatus.   The reasons for this performance were
many and varied.

The initial test with alum-treated, sand-filtered primary effluent was
conducted at an average pH of 5. 3,  adjusted with sulfuric acid.  The
product water flux decline was rapid, and visual observation of mem-
brane surfaces indicated inorganic salt precipitation.  An analysis was
run on the alum clarification plant output and revealed 108 mg/1 cal-
cium and 360 mg/1 sulfate.  These data together with the calculated
acid addition revealed the  following calcium and sulfate contributions
in the feed water:

       Calcium:      Indigenous                2. 7 mmol/1

       Sulfate:        Indigenous                3.8 mmol/1
                      Alum                      1.4 mmol/1
                      Acid                      4. 9 mmol/1

At this indicated solution ionic strength and at a 2% product water re-
covery ratio condition, these values result in calcium sulfate  saturation
with a concentration polarization of only 3. 4 at the membrane  surface.
Thus calcium sulfate precipitation cannot be ruled out as a possible
cause of product water flux depression under these operating conditions.
                                 20

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                                              Table 3

      AVERAGE WASTEWATER CONSTITUENT REJECTIONS AND PRODUCT WATER QUALITY
                                                  Rejections, %
                                                                          Product Water Quality
   Feedwater
Primary Effluent
Alum-treated,
Sand-filtered Pri-
mary Effluent
                     Axial
                    /elocit}
                     ft/sec
                      2. 58

                      6.45

                     12.9

                      2.58

                      2.58

                      2.58

Secondary Effluent   2. 58

                      2.58

                      2.58

                      2.58
Re-
over}
2
2
2
2
65
90
2
50
70
80
*
r, EC
93.7
95.5
98.0
94.0
93.7
95.7
96.9
84.2
86.8
85. 3
Tur-
bidity
100
100
100
100
100
100
100
100
100
100
Total
COD
94.2
96.0
97.8
85.4
95.0
-
94.6
96.4
96.5
97.0
NH4-N
84.7
89.5
-
88. 1
90.8
-
90.4
95.3
-
_
*
EC
125
85
39
130
307
404
58
536
547
567
Tur-
bidity,
Jtu
<0. 1
<0. 1
<0. 1
<0. 1
<0. 1
<0.1
<0.1
<0.1
<0. 1
<0. 1
Total
COD,
mg/1
12.9
9.9
5.5
11.7
10.2
-
3.7
7.7
6.8
4.5
NH4-I
mg/1
0.61
0. 40
-
0.43
0.67
-
0. 26
0.50
-
_
 £
 Electrical Conductivity, /umhos/cm at 25°C

-------
1  TUBE REPLACEMENT
PUMP FAILURE
2  ENZYMATIC CLEANSING
    I	I	I	
CHLORINE WASH
I      I
                      20    25    30    35
                     OPERATING TIME, days
           40
45
50
55
Figure 6.  REVERSE OSMOSIS PERFORMANCE WITH ALUM-
           TREATED SAND-FILTERED PRIMARY EFFLUENT,
           NONRECIRCULATING SYSTEM AT 700 psig
                          22

-------
Reasoning that no addition of sulfuric acid would result in less chance
of calcium sulfate precipitation, the next test was conducted with no
pH adjustment.  Operation of the system at a natural pH of 6. 8 did
result in a slight reduction in flux decline, but anticipated results were
not achieved.   Visual inspection of the membrane surfaces  revealed a
thick fluffy green organic growth that was easily removed and beneath
which the membranes were very clean.  The membranes were then
twice washed for 20 minutes with 30 mg/1 of chlorine.  The washings
resulted in removal of large quantities of brown organic matter fol-
lowed by a dramatic improvement in product water flux.  Chlorination
was  instituted on a continuous basis at 4 mg/1 dosage.  Chemical analy-
ses of the fluffy growth disclosed 1. 71% phosphorus,  0. 25% calcium,
0. 74% sulfate,  1.19% carbonate,  67. 13% volatile matter, and 28. 98%
unidentified material.   These proportions indicate that cellular material
could be the principal constituent of the membrane deposits.

Insoluble phosphate deposition,  a potential occurrence at pH values
above 5, was not seriously considered because of the high phosphate
removal efficiency of the alum clarification process.  Analyses,  pre-
sented in Table 2,  indicated only 0. 06 mg/1 of phosphorus in the alum
clarification plant clearwell.

The  removal of organic  growth from the membrane surface was  imme-
diately followed by a resumption of the substantial product water flux
decline.   To prevent the possible occurrence of calcium carbonate
deposition at the relatively high pH level, hydrochloric acid was added
to the feed stream to obtain a pH of 5. 3.  Visual inspection of the mem-
branes indicated that the new material coating the membrane was unlike
the previous "growth" and chlorination was discontinued.  Product water
flux continued to drop at the steady rate shown in Figure 6  during the
period between the 37th and 43rd operating days.  The test was shortly
thereafter discontinued with a final analysis  of membrane deposits
providing 0. 044% calcium,  4. 98% sulfate, 0. 38% carbonate, 4. 2%
phosphorus, 71.62% volatile matter,  and  18.78% unidentified material.

Daily system depressurization for 15 minutes accounted for an average
immediate product water flux increase of 18. 1%.

Wastewater constituent rejections for the alum-treated, sand-filtered
primary effluent are presented in Table 3.   The  relatively  low COD
rejection of 85. 4% was in part due to the relatively high ratio of dis-
solved to suspended organic matter present in this sewage.  Dissolved
organic matter, more easily transported  through the membrane than
suspended matter, lowers the COD percentage rejection below that
obtained with other sewages. Specific details on membrane perfor-
mance with alum-treated, sand-filtered primary effluent are available
in Appendix C.

The  comparison test with concentrated, i.e. , high product water re-
covery ratio,  alum-treated,  sand-filtered primary effluent was  ori-
ginally started at 90% product water recovery ratio and a pH of 5. 3
                                 23

-------
adjusted with sulfuric acid.  Product water fluxes regularly declined
to zero within one day, as shown in Figure 7, necessitating frequent
restorations of membrane flux with an enzyme-active laundry presoak
formulation. Analysis of the membrane deposits indicated that 77% by
weight was calcium sulfate; the remaining 23% was unidentified.

Chemical analyses and equilibrium calculations indicated that an esti-
mated maximum product water recovery ratio of 70% may be allowed
with no sulfuric acid addition before calcium sulfate precipitation is
expected to occur.   The test was restarted at a natural pH of 7. 2 with
no acid addition and a recovery ratio of 65%.  The improvement in
product water flux decline was dramatic but short of acceptable per-
formance.  A pump failure necessitated operation at one-half feed
rate capacity (1.29 ft/sec axial velocity) over a portion of the test,
but it did not appear to have had a  decided influence on membrane
performance.  An attempt to rescue the test from possible salt depo-
sition problems by reducing the  feed water pH to 5. 0 with hydrochloric
acid did not alter the flux decline.   The test was therefore discontinued.

Average flux increase due to daily 15-minute  system depressurization
for the combined 90 and 65% product water recovery ratio conditions
was 16. 7%.

Due to the shortness of the text periods for the alum-treated, sand-
filtered primary effluent processed in the recirculating system, the
specific wastewater constituent rejections, presented in Table 3, for
COD and ammonium nitrogen are the result of a small number of sam-
ples and should be  compared with caution. Daily product water fluxes
and wastewater constituent rejections are given in Appendix D.

SECONDARY EFFLUENT

Tests at a product water recovery ratio of less than 2% over most of
the test period were conducted at a pH of 5. 3 using sulfuric acid for
adjustment, at a nonrecirculating feed water axial velocity of 2. 58 ,
ft/sec,  at a 700-psig operating pressure, and with a daily 15-minute
depres surization.

Product water flux, with secondary effluent,  shown in Figure 8, exhibi-
ted a moderate decline from a high transient of 35 gal. /(sq ft)(day) to a
low of 6. 7 gal. /(sq ft)(day) over an initial period of 65 days.  Following
a 10-minute  soak of the membranes with an enzyme-active laundry pre-
soak formulation, the fluxes of the older tubes were restored to 50% of
their original values.   Thereafter  a product water flux decline similar
to that noted earlier repeated itself for the duration of the 98-day test.

It is interesting to  note the similar behavior of the four tubes in the
system with regard to flux increases and decreases, demonstrating
most likely the dependence of performance on varying feed water
quality.
                                 24

-------
  100
   90
   80
   70
   60

   50
*
 *
O

UJ
*
0

x
D

REJECTION
                                 90
                                 80
                                  0
                                 60

                                 50

                                 40


                                 30
                                                       "1

                                                          jjT
                                                          0>
           1 TUBE REPLACEMENT
                                             Recovery,%
                                             pH
                                             Acid

                                             Feed Velocity, ft/sec
                            2  ENZYMATIC CLEANSING
                  10
               15
20
•Jr
30
35
40
                                                     -10
                                                       9

                                                       7
                                                       6

                                                       5

                                                       4
                                    UJ
                                    O
                                    iZ
                                    u.

                                    §
                                    ui
                                    <
                                    oc
                                                                   UJ
                          OPERATION TIME, days
     Figure 7.  REVERSE OSMOSIS PERFORMANCE WITH
                 CONCENTRATED ALUM-TREATED, SAND-
                 FILTERED PRIMARY EFFLUENT, RECIR-
                 CULATING SYSTEM AT 700 psig
                                      25

-------
   100
   90 |—   REJECTION
   80
   70
   60
   50
z
o
K   40  -
o
LU
cc
1-
C/l
a
I
    30
    20
                       < 2% Recovery
                        5.3 pH
                        H2SO4 Acid
                        2.58 ft/sec Feed Velocity
                        700 psig
•90
-80
 70
.60
 50

-40

-30


-20
                                                                                                                                            z
                                                                                                                                            Hi
                                                                                                                                            u.
                                                                                                                                            at
                                                                                                                                            O
                                                                                                                                            c
                                                                                                                                            111
                                                                                                                                       -10  <
                                                                                                                                         9   i
                                                                                                                                         s   S
             1  TUBE REPLACEMENT
             2  ENZYMATIC CLEANSING
             !      I      I     I
                  10     15     20
                                     25    30     35    40    55     50    55
                                                            OPERATING TIME, days
                                                                                 60
                                                                                        65
                                                                                              70
                                                                                                    75
                                                                                                           80
                                                                                                                 85
                                                                                                                        90
                                                                                                                                    10Q
                  Figure  8.   REVERSE OSMOSIS PERFORMANCE WITH SECONDARY EFFLUENT,
                                NONRECIRCULATING SYSTEM

-------
Figure 9 provides a comparison between the product water flux of one
tube and daily variations  in feed water secondary effluent turbidity,
chemical oxygen demand,  and electrical conductivity.  Cause and ef-
fect relationships are difficult to ascertain because variations in flux
decline are slight and membrane fouling may easily be influenced by
factors other than those presented here.  While the increased values
for turbidity and dissolved organic matter in late September do corres-
pond to an  increase in product water flux decline,  other high values for
these parameters and total dissolved solids cannot be  definitely related
to any deviation from the normal flux decline rate.

The average flux increase resulting from daily depressurization of the
system for 15 minutes was 4%.

Reference  to Table 3 reveals the extremely good rejection characteris-
tics of the  reverse osmosis process with secondary effluent.  Average
rejections  for electrical conductivity,  chemical oxygen demand, and
ammonium nitrogen were  96. 9,  94.6,  and 90. 4%,  respectively.  The
reduction in turbidity was found to be so complete as to provide a
product water quality below the accurate sensitivity of the turbidimeter.

An analysis of surface deposits, scraped from  a membrane treating
secondary  effluent,  indicated that the solids composition was  0. 71%
phosphorus, 0.47% calcium,  0.2% sulfate, 94.5%  volatile  matter,  and
4. 12 unidentified material.  This would indicate that at a product water
recovery ratio of 2%, salt precipitate deposition was not a problem,
but dissolved and undissolved organic substances did contribute to
membrane deposits.

Detailed wastewater  constituent rejections and  daily product water
fluxes with secondary effluent at a low recovery condition  may be found
in Appendix E.

Concentrated secondary effluent at 80, 70, and 50% product water re-
covery ratios  experienced similarly rapid product water flux declines,
as shown in Figure 10.  The cause of the observed declines was not as-
certained but appear similar  in nature to those associated with inorganic
salt precipitation.  Standard conditions for the  concentrated secondary
effluent test were identical with the nonrecirculating system except in
the use of hydrochloric acid for pH control.

The average recovery of product water flux due to daily system de-
pressurization of 15  minutes  was 19.8%.  Specific details  of membrane
performance with concentrated secondary effluent are  available in
Appendix F.
                                 27

-------
tv
00
              PRODUCT WATER FLUX
                                                                                    Enzymatic Membrane Cleansing
              ELECTRICAL

              CONDUCTIVITY
        1500
               JULY
AUGUST
SEPTEMBER
                                                                                                OCTOBER
                             Figure 9.  COMPARISON BETWEEN PRODUCT WATER FLUX
                                        AND SECONDARY EFFLUENT QUALITY

-------
               REJECTION
                                      Recovery, %

                                      pH
                                      Acid

                                      Feed Velocity, ft/sec
               FLUX
                        4   *
                        2   2
  1   TUBE REPLACEMENT
      I      I       I      I
2  ENZYMATIC CLEANSING
   I      I       I      I
            10     15    20     25    30
                    OPERATING TIME, days
                     40
                            90
                            80
                            70
                            60

                            50

                            40


                            30
                                                         20 J

                                                             u
                                                             sr
                                                        -10   UJ
                                                         9   o
                                                         8   £
                                                             ui
                                                             8
                                                       —-|6   in
                                                             tc.
                                                             a
45
Figure 10.  REVERSE OSMOSIS PERFORMANCE WITH
             CONCENTRATED SECONDARY EFFLUENT,
             RECIRCULATING SYSTEM AT 700 psig
                            29

-------
                             SECTION V

                             DISCUSSION
The test program has provided much useful data on a principal obstacle
to effective treatment of municipal wastewater by the reverse osmosis
process; namely,  membrane fouling.  Several methods of operation
would appear eliminated from  further consideration, but one successful
method was obtained with primary effluent that could provide a practical
means for the treatment of primary effluent by the reverse osmosis
process.

The product water flux decline observed upon processing municipal
wastewater by  reverse osmosis is greatly dependent on the nature  of
the wastewater .constituents.   There are three general classes of sub-
stances that when deposited on a membrane surface produce a marked
reduction in product water flux.   These are suspended particulates,
ranging in size from settleable matter to finely dispersed colloidal
solids; inorganic salt precipitates, created from saturated  solutions
occurring at or near the membrane surface;  and dissolved organic
matter, characterized by a very high  volatile solids content.  There
are also sewage constituents,  which were not identified by analysis,
but which appear to affect membrane performance when no  change  was
discernable in  measurements of the aforementioned three classes of
foulants.  It is  nevertheless likely that these unknown foularits, present
possibly in the  unidentified fractions of analyzed membrane deposits,
may be classified under the aforementioned three general categories.
Several methods of pretreatment were explored in this program to
eliminate or greatly reduce the effects of foulants on reverse osmosis
performance.

Suspended and  dispersed particulates  were controlled by three methods:
removal of particulates from the primary effluent feed water stream by
chemical flocculation with alum followed by sedimentation and sand fil-
tration, which  reduced average feed water turbidities from 6l to 3. 8 Jtu;
controlling particulate fouling  by the use of an anionic polyelectrolyte,
Zimmite 190,, (previous studies (Ref.  1) had indicated that the poly-
electrolyte flocculated dispersed matter into a loose bulky form that
would not deposit on the membrane and would be swept away by the
bulk wastewater stream); and increase of feed water flows to a maxi-
mum value of 10 gpm, corresponding  to an axial velocity of 12. 9 ft/sec,
for hydraulically inducing relatively high turbulent conditions within
the tubes.

The precipitation of certain inorganic salts,  caused by a saturation of
respective salt ions at or near the membrane surface, was reduced or
eliminated by adjustment of the hydrogen ion content of the water.  Pre-
vention of precipitation of calcium phosphate and calcium carbonate
compounds at normal wastewater  concentrations is  readily  accomplished
by increasing the hydrogen ion content of the water to a pH  of 5.  This
                                 31

-------
control method is ineffective, however, for calcium sulfater another
common inorganic precipitate.  Reductions  in concentration of either
the calcium or sulfate ion by such means as species removal or de-
creased concentration polarization at the membrane surface will limit
salt deposition on the membrane.

Dissolved organic matter, the third class of foulants,  is ordinarily
removed by biological treatment.  The final product of biological
treatment is quite different from  a primary effluent that might be
subjected only to reduction of dissolved organic substances.  Lacking
other effective facilities for removing dissolved organics from  pri-
mary effluent, tests were conducted with secondary effluent, which
also is  usually characterized by a relatively low  suspended solids
content.

Periodic cleansing of the membranes is another method of controlling
membrane fouling by temporarily restoring product water flux.  An
enzyme-active laundry presoak formulation was employed in this pro-
gram as a cleansing agent.

Addition of Zimmite 190 at the dosages employed had no noticeable
effect on membrane performance.

A marked improvement in product water flux was observed as axial
velocities of primary effluent feed water increased (cf. Figure  5).
Comparison  of these data with those in Figure 8 reveals a membrane
performance for primary  sewage very similar to that  obtained with
secondary effluent at low axial velocities and product water  recovery
ratios.   The feed water axial velocity of 12. 9 ft/sec was chosen for
study because of the simplicity of manifolding the outputs of two fixed-
capacity pumps.   It is possible and likely that an intermediate axial
velocity between 12. 9 and 6. 45 ft/sec could provide acceptable  product
water flux performance.   The  results obtained at the high feed rate in-
dicate that proper control of hydraulic conditions within the  tubular
membranes permits retention in the feed stream of all the natural
constituents  of primary effluent without resort to major pretreatment
processes.  'The turbulence created at high feed water axial velocities
reduces the boundary layer at the membrane surface and increases
shear forces acting on materials  deposited on the membrane, providing
a deterrent to most membrane foulants.  Similar benefits have  been
reported by others with pulp mill wastewaters (Ref. 3) and with silt-
bearing river water (Ref.  4).

It was shown in Table 3 that increasing feed water axial velocity pro-
vides increasingly better product water qualities from primary effluent.
This is due to a reduction in liquid boundary layer thickness and con-
centrations of wastewater constituents immediately adjacent to  the
membrane surface. At a  feed water axial velocity of  12. 9 ft/sec with
primary effluent, the product water quality closely approached that
obtained at 2.58  ft/sec with secondary effluent,  which contains  generally
                                 32

-------
lower concentrations of waste constituents.  Thus, in situations where
recirculation of waste streams is used to maintain minimum hydraulic
conditions for prevention of membrane fouling, a  reduction in overall
product water quality usually results  since more membrane area is
exposed to more highly concentrated wastewaters.  This deterioration
in product water quality due to recirculation can be offset by operating
at a high feed water axial velocity.

A daily 15-minute discontinuance of feed water flow and reduction to
atmospheric pressure within the tubes produced a beneficial effect for
all feed water conditions studied.  The effectiveness  of the  depressuri-
zation procedure is directly proportional to the extent and rate  of solids
deposition on the membrane surface.  Primary effluent tests experi-
enced flux recoveries immediately after shutdown ranging from 99.4%
at 2. 58 ft/sec axial velocity to 1. 1% at 12. 9 ft/sec.  Tests  with alum-
treated, sand-filtered effluent and secondary effluent at 2. 58 ft/sec
axial velocity underwent flux recoveries of 16. 7 and  19. 8%, respec-
tively.  These  recoveries  are attributed to a backflow of purified water
•from the membrane interior created by normal osmotic pressure that
loosens deposited materials.  Since regular depressurizations  appear
to produce an increase in product water  flux,  they should not be over-
looked as a possible standard operating procedure.

Removal of suspended matter by alum addition,  flocculation,  sedimen-
tation,  and sand filtration would normally permit  an  examination of the
effects  on product water flux decline of sewage constituents that would
be overshadowed by gross amounts  of particulate  matter.   However,
inorganic salt deposition was a major problem in  that substantial flux
decline was observed at low product water recovery  ratio of less than
2% with alum-treated primary affluent.   The analysis of membrane
deposits from a test with this feed water subjected to various pH values
but no sulfuric acid addition indicated 4. 98% sulfate, a high level of
sulfate  deposition.

The maximum  calculated product water ratio was 84% for primary
effluent that contained indigenous calcium and sulfate concentrations
of 98 mg/1 and 181 mg/1, respectively.   The addition of alum or sul-
furic acid for pH control further reduced allowable product water
recovery.  It was estimated that the simultaneous use of both chemi-
cals would permit a theoretical maximum product water recovery
ratio of 55%.   The declines presented in Figure 7 substantiate the
inability to maintain product water  flux at any appreciable recovery
ratio with this  feed water.

It is conceivable that deposits on the membrane surface from waste-
waters  produce a concentration polarization much higher than is
commonly associated with unfouled membranes.   It would seem,
therefore, that alum treatment of a high-sulfate content sewage for
removal of membrane foulants would  have limited application under
the standard operating conditions of this program.
                                  33

-------
An alternative pretreatment process that may be of use and should be
studied further is clarification of the primary effluent with lime.  Not
only does lime flocculate disperse particulates, but,  unlike aluminum
sulfate,  it also lowers the calcium content of the sewage,  reducing op-
portunities for calcium sulfate salt precipitation.  Lime has the added
advantage of not introducing sulfates to the water and may itself be re-
covered for future reuse.  Clarification with lime results  in an increased
feed water pH, but inasmuch as pH adjustment downward may be indi-
cated in any  event for the reverse osmosis process, and since lime
clarification reduces the alkalinity of the feed water, the amount of
acid required may be little affected.

The  occasional indications of salt precipitation on membrane surfaces
at low product water recovery ratios may also have  been due to tran-
sient high concentrations of inorganic species in the wastewater from
the City of Corona.  During the very early hours of the morning, ex-
tremely high levels  of calcium and magnesium are present in the sewage
as the result of automatic  regeneration operations of numerous domes-
tic ion exchange water softeners.  Water Reclamation Plant records
indicate that the measured peak levels of sewage constituents arising
from the regenerating operations occur at  0500 hours  and  are  3, 900
ftmhos/cm electrical conductivity, 1,275 mg/1 chloride, and 650 mg/1
total hardness.  By 0800 hours the levels have dropped to  1, 500
ftmhos/cm electrical conductivity, 175 mg/1 chloride, and 230 mg/1
total hardness.  From 1100 hours until early the next morning these
constituents  maintain a steady level of 1, 300 /t mhos /cm electrical
conductivity, 175  mg/1 chloride,  and 230 mg/1 total  hardness.  It is
evident that the nonrecirculating, low recovery reverse osmosis sys-
tems were subjected daily to short-term,  high levels of potentially
damaging inorganic  salt concentrations, which were not evident in grab
samples taken for analysis or for recirculating system feed water during
a standard working day.

The  product  water flux decline associated with a membrane fouled pri-
marily with dissolved organic matter, which was shown in Figure 8,
reveals  that  dissolved organics have a lesser effect  than do suspended
particulates  or precipitating inorganic  salts.  The moderate flux de-
cline achieved with a secondary effluent adjusted only for pH level
would tend to indicate that successful operation of a  large-scale reverse
osmosis plant treating secondary effluent may be achieved by inter-
mittent cleansing  of the  membranes to restore product water flux to
acceptable levels.  However, rapid flux declines were experienced at
50,  70",  and 80% product water ratios due presumably to inorganic salt
precipitation.  Inability  to operate at any appreciable recovery level
with this particular feed water due to salt precipitation limits  its use
in the reverse osmosis process under the standard test conditions en-
countered  at the City of  Corona.  There are many locations and appli-
cations, however, that would not be limited by dissolved salts  in the
feed water.
                                 34

-------
Lesser amounts of calcium sulfate deposits,  and attendant higher pro-
duct water fluxes, occurred with secondary effluent dosed with sulfuric
acid than with primary effluent dosed with sulfuric acid, even though
the same concentrations of calcium and sulfate existed in both sewages.
The difference is attributed to the degree of membrane fouling caused
by suspended matter and organic substances  in the sewages.  Rela-
tively heavy fouling by these materials with primary effluent feed water
retards to  a greater extent the back diffusion of inorganic salts from
the membrane  surface,  resulting in higher salt concentrations and a
more saturated condition than is experienced by the relatively light
membrane fouling with secondary effluent.

Membrane rejuvenation by cleansing with an enzyme-active laundry
presoak formulation proved beneficial for both primary and secondary
effluents where the principal causes  of fouling were suspended and dis-
solved organic matter.  The cleansing procedure was  also of value in
removing inorganic  salt precipitates as in the case of  the test with alum-
treated, sand-filtered primary effluent,  where numerous cleansings
were performed in an effort to maintain product water flux during high
product water recovery conditions.

Occasionally, the entire series of tubes in a  single test experienced a
simultaneous rejuvenation in product water flux.   This occurred with
secondary  effluent after 15 days of operation (cf. Figure 8)  and primary
effluent at  a 6.45 ft/sec axial velocity after 2 days of operation (cf.
Figure  5).   This  unusual performance could not be attributed to irre-
gular operating procedures or technical difficulties with the test equip-
ment.   It is quite possible that some unknown characteristics of the
feed water was directly responsible for inhibition of product water
flux. The  action may be due to a cleansing effect of some constituent
that was intermittently present in the feed water or some substance
previously deposited on the membrane that lost its adhesiveness  to
the membrane  surface.  Unexplained results such as these point out
that even while reverse  osmosis may now be used to treat wastewater,
a great deal of information is lacking about all the  factors influencing
this process.
                                 35

-------
                            SECTION VI

                       ACKNO WLEDGMEN TS
The 6-month program was performed by the Envirogenics Company,
a Division of Aerojet-General Corporation, at El Monte,  California,
under the direction of Mr. Gerald Stern, Project Officer, Water Quality
Office.  Envirogenics Company personnel participating in the program
were Dr.  D. L. Feuerstein, Program Manager; Mr. T. A.  Bursztynsky,
Project Engineer; Messrs.  H.  Barnard and R. Nygren, Laboratory
Technicians; and Mrs. M. D. Robinson, Secretary.

The complete cooperation of Mr. Arthur E.  Goulet, Director of Public
Works,  Mr.  Gilbert Cleveland, Superintendent of Water Pollution Con-
trol, and the staff at the Water Reclamation Plant of the City of Corona,
California,  in providing  a site for the study and very helpful assistance
to this program is gratefully appreciated and acknowledged.
                                 37

-------
                           SECTION VII

                           REFERENCES
1.     Reverse Osmosis Renovation of Municipal Wastewater
           (17040 EFQ 12/69) Washington: Federal Water Quality
           Administration (December 1969).

2.     Standard Methods for the Examination of Water and Waste -
           water, 12th Ed. , New York:  Amer. Pub.  Health Assn.
3.    Wiley,  Averill J. , Dubey,  George A. , Holderby, J. M. ,  and
           Ammerlaan, A. C. F. ,  "Concentration of Dilute Pulping
           Wastes by Reverse Osmosis and Ultra Filtration, " Jour.
           Water Poll. Control Fed. , 42, R279 (August  1970).

4.    1969-1970 Saline Water Conversion Report, Office  of Saline
           Water, U. S.  Department of the  Interior, p.  467.
                                 39

-------
                           SECTION VIII

                             GLOSSARY
BOD - Biochemical Oxygen Demand.  By means of a standardized labo-
ratory procedure, an indication of the concentration of chemical species
that can be oxidized by micro-organisms is derived.

Coagulation - The mutual attraction and coalescence of oppositely
charged colloids to produce a (usually gelatinous) precipitated phase.
In water treatment, the addition and subsequent hydration of oxides
of aluminum or iron produce positively charged colloids which can
be used to remove negatively charged organic colloids.

COD - Chemical Oxygen Demand.  By means of a standardized labora-
tory procedure, an indication of the concentration of chemical species
that can be chemically oxidized is derived.

Electrical Conductivity -Also called Conductance, this Ohmic property
defines the ability of a solution to pass current and is expressed as the
reciprocal of resistance.  Its magnitude is determined by the nature
and concentrations of the ions present.

Flocculation - Small,  coagulated particles become accreted to form.
larger, more precipitable structures.  This process is promoted
through the use of chemical coagulants,  adjustment of the physical or
chemical  condition of the system, or, biologically, through micro-
organism growth and activity.

Polyelectrolyte - A synthetic or natural polymeric material in which
the monomeric unit features an ionizable group.  Depending on the
nature of  the latter, a poly electrolyte may be  cationic, anionic, or
amphoteric  (e.g., proteins).  When dispersed, such materials can
undergo coagulation with oppositely charged colloids.

Primary Effluent - The product water resulting from the primary
sewage treatment process, which consists of screening,  grease and
scum removal, and sedimentation.

Product Water Flux -  The rate  of flow of water passing through a  unit
area of reverse osmosis  membrane under specified conditions of pres-
sure, temperature, and feed water solution composition (typically,
gal. /sq ft-day).

Product Water Flux Decline - The inherent property of reverse osmosis
membranes to experience permeability loss under fixed operating con-
ditions.  Flux decline  rate is dependent on flux level, boundary layer
conditions,  Reynolds  number,  and other system properties.
                                 41

-------
Reverse Osmosis  - A separation technique where application of pres-
sure greater than  the solution osmotic pressure causes relatively pure
water to pass through a membrane.

Reynolds Number  - A dimensionless number proportional to the ratio
of internal force to viscous force in a flow system, whose value is
indicative of the degree of turbulence of the fluid.

Sand Filtration -  The process of removing coagulated solids within a
thick column of sand, wherein such particles become lodged and aggre-
gated in the interstitial spaces of the bed channels.  Filter rejuvenation
is usually accomplished by turbulent back washing.

Secondary Effluent -  The  product water  resulting from the secondary
sewage treatment  process, which consists of some form of biological
assimilation and degradation of primary effluent plus sedimentation.
                               42

-------
                            SECTION IX

                            APPENDICES


Appendix                                                      Page

    A.      Initial Osmotic Properties of Reverse Osmosis       44
                 Membranes

    B.      Performance and Water Quality Characteristics,      46
                 Zimmite  190-treated Primary Effluent,
                 Nonrecirculating System

    C.      Performance and Water Quality Characteristics,      50
                 Alum-treated, Sand-filtered Primary
                 Effluent,  Nonrecirculating System

    D.      Performance and Water Quality Characteristics,      52
                 Alum-treated, Sand-filtered Primary,
                 Effluent,  Recirculating System

    E.      Performance and Water Quality Characteristics,      54
                 Secondary Effluent, Nonrecirculating
                 System

    F.      Performance and Water Quality Characteristics,      60
                 Secondary Effluent, Recirculating
                 System
                                 43

-------
            Appendix A

INITIAL OSMOTIC PROPERTIES OF
  REVERSE OSMOSIS MEMBRANES

Production Line Quality-Control Test
Tube
Designation
78-11
82-1
87-1
93-1
77-H
81 -III
191-1
86-n
67-1
172-1
83-11
184-1
84-1
70 -IV
74-11
88-1
69-1
163-11
Water Flux,
gal/(sq ft) (day)
37.6
36.6
37.9
34.4
34.4
29.9
26.8
30.2
39.1
29.0
31. 8
29.0
39.1
31. 8
36.9
32. 6
42.9
35.8
Salt
Rejection,
%
88.7
87. 2
89. 1
81. 8
81.8
90.1
89.9
86.7
83.7
86. 5
87.7
88.4
88.7
86.8
90.7
91.2
82.4
84.4
                44

-------
       Appendix A (Continued)

INITIAL OSMOTIC PROPERTIES OF
 REVERSE OSMOSIS MEMBRANES
Production Line Quality-Control Test
Tube
Designation
115-IL
167-11
98-11
185-1
106-1
165-n
242-1
99-11
171-n
285-1
287-1
293-ni
294-11
288-1
300 -III
281-1
301 -IV
Water Flux,
gal/(sq ft)(day)
22. 3
31.4
39.8
45.0
27. 3
22. 3
31.9
36.4
29.0
36.6
36.6
39.8
34. 8
31.0
34.8
28.5
31.0
Salt
Rejection,
%
85.9
85. 2
89.3
85.7
90,. 8
85.9
89.2
86. 2
88. 1
85.0
80.5
84.5
88.7
88. 1
88.9
89.2
95.4
                45

-------
                                                         Appendix B
                                PERFORMANCE AND WATER QUALITY CHARACTERISTICS,
                                        ZIMMITE 190-TREATED PRIMARY EFFLUENT,
                                 NONRECIRCULATING SYSTEM(700 psig, 2% Recovery)

Date

11 Aug 70
1 2 Aug 70
1 3 Aug 70*
14 Aug 70*
18 Aug 70
19 Aug 70
20 Aug 70*
21 Aug 70
22 Aug 70
23 Aug 70*
24 Aug 70
25 Aug 70*
26 Aug 70
27 Aug 70
28 Aug 70
29 Aug 70*
30 Aug 70
31 Aug 70*
. , FEED WATER
Axial
Vel.
ft/ sec
2. 58
2.58
2.58
2. 58.
2.58
.2.58
2.58
2.58
2.58
2. 58
2.58
2.58
2.58
2.58
2.58
2.58
2.58
2. 58
PH

6.0
.6.0
6.0
6.0
Pi
5.9
6.0
6.0
6.0
6.~0
6.1
6.1
6.1
6.0
6.0
6.0
6.1
6.2
6.0
Acid
Feed
H2S04
H2S04
H2S04
H2S04
mp Ri
H2S04
H2S04
H2S04
H2SO4
H2S04
H2S04
H2S04
H2S04
H2S°4
H2S04
H2S04
H2S04
H2S04
Zim.
190
mg/1
2
2
2
2
ipa ir
2
2
2
2
2
2
2
0
0
0
0
0
0
1
Temp
°C
33 '
33
31
34
35
36
31
30
31
30
31
32
32
32
31
30
30
32
EC

1950
1590
1800
2250
1950
1700
1900
1750
1950
2100
1900
2000
1800
2000
1950
2100
2100
1850
COD
mg/1
-
-
389
-
268
-
-
-
54
-
-
248
226
296
- .
203
-

NH..-N
.5
mg/1

-
-
-
_
-
-
-
-
-' '
-
1.5
-
3.5
• -
-
-
Tur- .
bidity
Jtu
48
64
-
-
53
64
51

49
44
67
49
47
58
60
58
48 .
- 1 66
PRODUCT WATER
Flux, gal/(sq ft) (day)

1
40a
5.5
10.5
11.2
10. 3e
3,0
15.9
8.8
17.7
22.4
6.6
21.1
14.7
8.1
3.0
6.7
3.9
8.8
2
41. 9b
5.6
10.6
11.6
9.4£
3.0
9.5
5.9
3.7
4.7
2.6
7.0
9.6J
6.7
2.9
14.4
4.8
11.7
3,
44. 4C
5.6
11.2
10.8
11. 4g
2.8
16. 7
8.4
4.3
6.5
2.9
18. 91
13.7
8.3
3.0
4.4
3.3
6.7
4
40.3d
5.5
10.8
10.8
8.7h
3.6
16.7
8.3
3.7
6.3
3.0
18.1
11.7
8.9
4.8
10.0
4.4
11.4
EC, ^imhos/cm

1
70a
95
58
50
I36e
304
55
126
67
59
84
51
74
71
122
89
116
6.0
2
86b
112
71
46
125£
228
62
90
160
75
190
102
70j
73
146
53
94
49
3
91C
126
180
70
80g
154
52
146
142
150
392
99£
132
100
186
130
143
110
4
78d
102
67
46
76h
155
42
54
77
60
84
47
40
44
55
44
74
54
COD
mg/1
1 -4
-
-
-
-
8.6
•
-
-
17.5
-
-
19.2
25.8
5.98
-
13.3
-
-
NH,-N
nig3/!
i - 4
-
- •
-
-
-
-
-
"
- •
-
-
0.5
-
0.65
-
-
-
-
a Tube 81 -III; b Tube 86-11; cTube 172-1; dTube 185-1; eTube 191-1; £Tube 67-1: gTube 83-11; hTube 184-1; *Tube 185-1; jTube 171-11
*Enzymatic Cleansing

-------
                                                    Appendix B (Continued)
                                 PERFORMANCE AND WATER QUALITY CHARACTERISTICS,
                                         ZIMMITE 190-TREATED PRIMARY EFFLUENT.
                            NONRECIRCULATING SYSTEM  ( 700 psig, 2% Recovery)
Date
1 Sep 70
FEED WATER
Axial .
Vel.
ft/ sec
2.58
2 Sep 70 2. 58
3 Sep 70 2.58
4 Sep 70*
5 Sep 70
6 Sep 70
7 Sep 70*
8 Sep 70*
9 Sep 70
10 Sep 70*
11 Sep 70
12 Sep 70
13 Sep 70*
14 Sep 70
15 Sep 70*
16 Sep 70
17 Sep 70
18 Sep 70
2.58
2.58
2.58
2.58
2.58
-
2.58
2.58
2.58
2.58
2.58
2.58
6.45
6.45
6.45
PH
6.0

6.3
5.9
6.0
6.1
6.1
6.0
«•
-
6.1
6.5
5.7
-
5.1
6.2
6.2
6.2
Acid
Feed
H2S04
H2SO4
H,S04
£j ^
H2S04
H2S04
H2S04
H2S0.4
-
HC1
HC1
HC1
HC1
HC1
HC1
H2S04
H2S04
H2S04
Zim.
190
mg/1
1
1
1
4
4
4
4
4
-
2
2
2
0
0
0
2
2
2
Temp
°c
32
-
33
32
31
33
33
36
-
-
34
31
33
-
32
31
32
31
EC
1925
-
2000
1850
2100
1975
1840
2080.-
-
-
1900
1850
2425
•
2050
1850
1975
1760
COD
mg/1
-
-
186
-
104
' -
-
179
- •
-
-
-
-
-
246
-
275
"
NH3-N
mg/1
-
-
3.5
-
-
-
-
-
-
-
-
-
-
•
-
3.8
-

Tut--
bidity
Jtu
52
-
55
58
73
58
-
72
-
'~.
57
63
64
-
73
65
73
54
PRODUCT WATER.
Flux, gal/(sq(ft)(day)
1
10.4
4.8
4.1
20. Ok
10.4
3.8
2.8
-
-
-
-

-
-
-
-
- •

2
14.3
8.6
12.0
35. 61
4.8
3.4
2.7
-
-
-
-
-
-
-
-
-
-•

3
3.8
-
-•
17.5n
9.6
3.3
2.7
-
-
20.0°
7.8
3.3
2.3
21. 8p
4.1
l'2.6
5.0
.7.1
4
5.6
-
-
1 26.9n
11.9
3.9
2.8
-
-
41.6
7,4
3.6
2.3
22.3q
4.7
13.0
5.0
7<1
EC, jimhos/cm
1
60
-
142
72k
90
215
244
-
-
-
-
-
-
-
-
-
-

2
49
-
_
651
260
405
500
--
-
-
-
-
-
-
-
-
-

3
110
-
- •
54m
70
178
212..
237
-
o
92
155
250
_P
40
78
114
75
4
54
-
-
36n
69
203
222
2 6'0
-.
-
190
240
480
_q
38
55
92
57
COD
mg/1
1 -4
-
-
6.5
-
6.4
-
-
37 .
-
-
-
-
-
-
14.6
-
15.4

NH3-N
mg/1
1 - 4
- .
-
0.5
-
-
-
-
-
-
-
-
-
.-
-
-
0.4
-

 Tube 185-1; XTube 167-11; mTube 191-1; nTube 171-11; °Tube 167-11; pTube 285-1; qTube 286-1
fcEnaymatic Cleansing

-------
                                                     Appendix B (Continued)
                                PERFORMANCE AND   WATER QUALITY CHARACTERISTICS
                                          ZIMMITE 190-TREATED PRIMARY EFFLUENT,
                                 NONRECIRCULATING SYSTEM(700 Psig, 2% Recovery)
Date
19 Sep 70
20 Sep 70
21 Sep 70
22 Sep 70*
23 Sep 70
24 Sep 70*
25 Sep 70
26 Sep 70
27 Sep 70
28 Sep 70
29 Sep 70*
3C Sep 70
1 Oct 70
2 Oct 70
3 Oct 70
4 Oct 70
5 Oct 70
6 Oct 70
7 Oct 70
FEED WATER.
Axial
Vel.
ft/ sec
6.45
6.45
6.45
2.58
2.58
2.58
2. 58
2.58
2.58
2.58
12.9
12.9
12.9
12.9
12.9
12.9
12.9
12.9
12.9
pH/
6.2
6.3
6.2
6.0
5.8
5.4
3.5
5.8
4.8
4.6
5.7
5.5
5
5
5.4
5.8
5.2
5
5.4
Acid '
Feed
H2S04
H2S04
H2S04
HC1
HC1
HC1
HC1
HC1
HC1
HC1
H2S04
H2S04
H2S04
H2SO4
H2S04
H2S04

H2S04
H2S04
Zim.
190
mg/1
2
2
2
2
2
2
2
2
2
2
0
0
0
0
0
0
0
0
0
Temp.
°C
32
31
31
32
34
33
33
33
34
34
31
31
32
33
32
32
31
-
30
EC
,1700
2125
1925
1700
2150
2175
1950
1 900.
2475
2275
2100
1925
1875
1800
1750
2050
2800
1600
1650
COD
mg/1
217
.-
-
218
-
376
-
250
-
-
317
-
261
-
185
-
-
-
-
NH3-N
mg/1
_
-
• -
- .
7.5
-
-
-
-

-
-
-
-'
-
-
-
-
-
Tur-r
bidity
Jtu
63
57
54
47
83
56
65
71
73
86
72
62
87
72
90
74
100
-
82
PRODUCT WATER
Flux, gal/(sq ft)(day)
1
_
-
-
. _.
_<
-
-
-
-
•
51r
27. 2
23.4
25.8
24.1
23.2
20.8
25.6
16. 3Z
2
.
-

- .
-
-
-
-
-
-
52s
26.3
27.8*
30.0
27.5
24.7
28. 8V
47X
31.9"
3
14.2
4.7
3.3
14.7
2.8
28.8
16.6
5.5
8.3
3.9
30.2
20.6
19.0
21.2
20.6
29U
45. 2V
45. 5*
25.6
4
17.5
5.6
3.4
15.4
3.0
27.8
17.0
5.6
8.5
3.8
27.4
19.4
17.8
20.4
19.7
19.4
17.5
20.6
17.5
EC, /imhos/cm
1
•_
-
• -
-
-
-
-
-
-
-
50r
32
85
60
63
53
108
100
16Z
2
_
-
-
-
-
-
-
-
-
-
50s
31
67*
51
45
44
78V
75X
39aa
3
64
136
122
136
202
178
50
84
69
144
37
24
36
29
25
26U
1300W
65^
27
4
45
84
93
116
134,
150
42
75
60
90
31
22
25
23
21.5
22
116
44
20
COD
mg/1
1 -4
217
-
• -
218
-
376
'-
250
-
-
317

6.7
-
9.3
.•-
. -•
-

NH3-N
mg/1
1 - 4
_
-
-
-
7^5
-
-
-
-
- .
-
-
. -
-.
-

-
-

rTube 288-1; 8Tube 242-1; *Tube 287-1; UTube 191-1; VTube 171-11; "w Tube 99-11; XTube 293-III; yTube 302-III; ZTube 281-1; aatube 300-III.
*Enzymatic Cleansing

-------
                                                     Appendix B (Continued)
                                PERFORMANCE AND WATER QUALITY CHARACTERISTICS'
                                         ZIMMITE 190-TREATED PRIMARY EFFLUENT,
                              NONRECIRCULATING SYSTEM    ( 700 psig, 2% Recovery)
Date
8 Oct 70
9 Oct 70
10 Oct 70
11 Oct 70
12 Oct 70'
13 Oct 70
14 Oct 70



.
FEED WATER
Axial .
Vel.
ft/ sec
12.9
12.9
12.9
12.9
12.9
12.9
12.9




PH
5.7
5.6
5.9
5
4
4
4.5




Acid
Feed
H2S04
H2S04
H2S04
H2S04
H2S04
H2S04
H2S04




Zim.
190
mg/1
0
0
0
0
0
0
0




Tem^
°C
31
30
30
30
30
29
30




EC
2100
1950
1750
2200
2050
1950
2100




COD
mg/1
349
-
194
-
-
161
"




NH3-N
mg/1
—
-
-
-
-
-
"




Tur-
bidity
Jtu
62
55
70
42
66
61
65




PRODUCT WATER
Flux, gal/(sq ft) (day)
1
21.0
37.0bb
27.5
25.6
19.2
17,5
17.7




2
23.4
33. 7CC
24.1
22.2
17.3
15.4
io.odd




3
24.0
23.8
24.1
23.1
18.8
17,1
17.1




4
17.5
17.9
18.4
17.8
15.6
14.4
14.0




EC, jj.mhos/crn
1
90
44bb
37
36
30
31
33




2
33
33cc
25
22
18
22
70dd




3
25
22
22
24
18
24
29




4
21
20
20
24
16
22
23




COD
mg/1
1 -4
8.7
-
0

-
2.2
"


'
.
MH3-N
mg/1
1-4
_
-
-
-
-
-
"




bbTube 304-III; ccTube 301 -IV; ddTube 290-1

-------
                                                   Appendix C
                            PERFORMANCE AND WATER QUALITY CHARACTERISTICS
                            ALUM-CREATED,  SAND-FILTERED PRIMARY EFFLUENT.
                                          NONRECIRCULATING SYSTEM
( 700 osier. 2% Recoverv, ". 2. 5ft i
Date
6 Aug 70
7 Aug 70
8 Aug 70
9 Aug 70
10 Aug 70
11 Aug 70
1 2 Aug 70
1 3 Aug 70
14 Aug 70
1 5 Aug 70
16 Aug 70
1 7 Aug 70
18 Aug 70*
4 Sep 70
5 Sep 70
6 Sep 70
7 S.ep 70
8 Sep 70
9 Sep 70
FEED WATER
C12
mg/1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
pH
5.6

5.7
6.2
6.0
5.2
5.5
6.5
6.0
5.4
5.0
5.2
5.6
6.1
6.8
6.4
6.3
6.6
6.6
Acid
Feed
H2S04
H2SO4
H2SO,
H2SO4
H2S04

H2S04
H2S04
H2S04
H^O,
H2SO,
H2SO,
H2SO^
none
none
none
none
none
none
Temp.
°C
32
-
35
30
32
31
34
34
38
40
34
33
36
_•
33
34
34
36
34
EC
2150
-
2750
1850
2040
2000
1925
2200
2450
2250
2250
-
2350
a820
2350
2000
2300
2275
2140
COD
mg/1
-
-
-
-
-
-
-
117
' -
-
-
-
105
_
54

-
60
.
mg/1
'
-
-
-
-
-
-
-.
-
- .
-
-
-
-
-
-
-
_
4.8..
fur-.
bidity
Jtu
7.3
-
15
3.8
1.7
2.4
1.4
1.6

3.5
1.7
-
1.0
1.8
1..3
1.1
0.8
0.8
6.9
t/spc Axial Velocity).. .
PRODUCT WATER
Flux, gal/(sq ft)(day)
1
45. 2a
-
-
19.7
16.3
40. 4e
13.1
10.5
7.8
6.6
5.4
5.0
15.5
79h
21.2
23.4
17.0
33.5
35.4
2
41. 2b
-
-
22.8
11.7
38. 4£
16.2
12.6
8. 7
5.6
4.8
4.1
8.6
701
20.6
23.4
16.8
29.2
35.1
3
40. 2C
-
• -'
21.8
11.7
28.2
12.1
10.4
8.4
6.3
4.9
4.4
28.0
66j
20.6
23.1
23.0
19.' 2
34. 41
4
35. 8d
-
- .
23.0
14.0
29. Og
11.7
10.4
8.1
5.6
4.7
4.2
29.8
61*
17.2
23.4
17.0
14.3
27. 3m
EC, ^imhos/cm
1
250
-
940
252
975
72e
71
86
106
460
520
560
730
36^
140
103
171
77
245
2
106
-
142
49
74
66f
64
72
91
132
158
173
140
8601
142
100
145
82
180
3
73
-
88
46
88
49
51
58
73
80
100
104
1260
590j
245
235
800
506
1951
4
252
-
540
180
254
62g
63
74
82
120
120
122
L650
2 f /\*^
180
165
165
220
3QA^
COD
mg/1
1 -4
-
. -
-
-
_
-
-
-
-
-
-
-
21.9
_
0.9
-
-
7.- 9
.
NH3-N
mg/1
1-4
-
-
-
-
-
• -
-
-
.-
-
-
'
-
_
-
-
-
. • _
0.4
f;Tube 84-1; bTube 74-11;
 Tube 163-11; kTube 115-
CTube 88-1;   Tube 69-1; 6Tube 70
II; iTube 115-11; mTube 185-1.
-IV; £Tube 171-11; gTube 74-11; hTube 165-11; xTube 99-11; ^Tube 163-11;
 Enzymatic Cleansing.

-------
                                                          Appendix C (Continued)
                                         PERFORMANCE AND WATER QUALITY CHARACTERISTICS
                                         ALUM-TREATED,  SAND-FILTERED PRIMARY EFFLUENT.
                                                      NONRECIRCULATING SYSTEM
                                                 (700 psig. 2% Recovery.  .  2.58 ft/sec Axial  Velocity)
Date
10 Sep 70
1.1 Sep 70
12 Sep 70
13 Sep 70
14 Sep 70**
1.5 Sep 70
16 Sep 70*'
17 Sep 70
18 Sep 70
19 Sep 70
20 Sep 70
21 Sep 70*
22 Sep 70
23 Sep 70
24 Sep 70
25 Sep 70
26 Sep 70
27 Sep 70
28 .Sep 70
FEED WATER
ci2 ,
mg/1
0
0
0
0
0
0
4
4
4
4
4
4
4
4
0
0
0
0
0
PH
6.6
6.9
6.5
6.4
6.3
6.6
6.3
6.4
6.1
6.2
6.2
6.1
6.0
4.0
5.2
5.2
5.5
5.1
5.0
Acid
Feed
none
none
none
none
none
none
none
none
none
none
none
none
none
none
none
HC1
HC1
HC1
HC1
Temp.
°C
36
35
32
32
34
34
34
35
33
34
33
34
34
35
34
35
35
36
35
EC
2150
2100
2050
2300
2040
2090
2300
2250
1900
2100
2000
2125
2080
2300
2150
2290
2200
2600
2500
COD
mg/1
76
-
66
;
105
111
60
—
84
-•
59
-'
63
-
- '
NH3-N
mg/1

-
• -
:
1^5
-
-
-
-
4.4

-
~
-
-
Tur^
bidity
; J tu
6.6
1.8
7.7
1.1
1.0
8.2
3.9
9.6
3.7
5.2
2.3
1.7
2.5
1.6
1.3
8.4
6.6
3.8
2.4
PRODUCT WATER
Flux, gal/(sq ft)(day)
1
31.2
30. 6
19.1
12.3
9.6
6.1
32.7
20.2
15.0
18.1
16.0
11.9
11.0
9.2
8.4
11.0
8.6
8.3
9.,4
2
20.9
18.1
14.6
11.1
9.6
6.9
30.8
20.4
15.4
18.7
18.5
13.4
12.1
10.0
9.1
11.0
8.4
8.1
7.4 .
3
22.1
20.0
15.3
11.2
61.^
9.2
38.8
20.7
15.0
16.5
14.2
10.9
10.0
8.9
1 8.1
9.2
7.5
9.2
6.9
4
24.6
25.3
21.6
17.1
19.3
9.1
17.5
15.2
13.5
29.0°
25.2
13.6
13.7
10.9
10.3
17.9
10.8
9.4
7.8
EC, ^imhos/cm
1
110
94
155
129
140
193
118
106
99
114
128
.116
96
168.
104
138
ISO
200
126
2
167
180
208
155
170
300
96
69
82
133
96
93
96
132
92
113
160
180
155
3
162
122
150
129
168°
200
98
68.
88
141
1'04
108
105
148
122
143
210
225
198
4
155
130
13.2
62
146
165
76
41
46
124°
84
112
88
143
104
80
190
282
250
COD
mg/1
1 -4
7.0
-
7.8
:
29.1
32.3
17.1
-
6.0
-
5.3
-
3.8
-
-
NH3-N
mg/1
1 - 4
_
-
-
-
0.4
-
-
-
' -
0.5
-
-
-
-
-
Ul
         "Tube 290-1; °Tube 281-1
           Enzymatic Cleansing
         **30 mg/1 Chlorine Wash

-------
                                                          Appendix D
                                    PERFORMANCE AND WATER QUALITY CHARACTERISTICS
                                    ALUM-TREATED, SAND-FILTERED PRIMARY EFFLUENT,
                                               RECIRCULATING SYSTEM, (700 pgjg)
Date
1 2 Aug 70
1 3 Aug 70
14 Aug 70*
1 5 Aug 70*
1 6 Aug 70*
1 7 Aug 70*
9 Sep 70

10 Sep 70
11 Sep 70
12 Sep 70
13 Sep 70
14 Sep 70
15 Sep 70
16 Sep 70
1 7 Sep 70
18 Sep 70
19 Sep 70
20 Sep 70
21 Sep 70
FEED WATER .
Re-
cov-
ery
90
90
90
90
90
90
65

65
65
65
65
65
65
65
65
65
65
65
65
Axial
Vel.
ft/ sec
2.58
2.58
2.58
2. 58
2.58
2.58
1.29

1.29
1.29
1.29
1.29
1.29
1.29
. 1.29
1.29
1.29
1.29
1.29
1.29
PH
5.1
5.5
5.5
5.3
5.6
4.9
7.2

7.1
7.4
7.3
7.4
7.2
7.4
6.0
4.7
5.3
5.7
5.2
5.7
Acid -
Feed
H2S04
H2SO4
H2S04
H2S04
H2S04
H2S04
none

none
none
none
none
none
none
HC1
HC1
HC1
HC1
HC1
HC1
Temp.
°C
33
34
35
40
36'
35
31

36
38
37
34
34
34
35
35
35
33
33
33
EC
6800
9000
10000
10000
10600
10000
4400

4800
4800
4900
5000
4100
6900
. 5200
5400
5000
4200
4900
5000
COD
mg/1
-
127
-
-
-
-
_

202
-
198
-
-
278
-
254
-
170
-
-
NH3-N
mg/1
-
-
-
-
-
-
4.8

-
-
-'
-
-
-
8.0

-
- .
-
-
Tur-
bidity
Jtu
5.1
1.5.
-

7.8
-
_

9.2
5.8
4.3
1.4
1.0
1.0
4.6
2.1
2.6
5.8
2.1
0.5
PRODUCT WATER
Flux, gal/(sq ft) (day)
1
46. 8a
6.1
38.3
36.0
12.3
25.0
30. 6C

14.5
10.6
9.7
-
8.9
8.1
8.5
43. 5e
17.3
13.3
12.5
11.2
2
46b
5.1
38.3
36.0
9.6
25.5
27. 2d

14.4
11.0
9.4
-
9.1
8.4
8.6
9.6
7.3
6.9
6.6
6.1
3




















4




















EC, ^imhos/cm
1
185a
440
380
380
580
500
165°

150
235
295
225
190
365
307
352e
340
235
290
250
2
2l5b
480
402
385
440
455
170d

212
240
330
250
205
355
260
250
310
210
275
300
3




















4




















COD
mg/1
1 -4
-
- •
-
J7J1
-
-
.,
r
10.6
•-.
10.6
-
-
6.0
-
54
-
18
-
-
NH3-N
mg/1
1 - 4
. -
-
-
-
-
-
0.2

-
-
-
-
-
-
1.0
-
-
-
-
-
aTube 184-1; bTube 83-11; cTube 98-11; dTube 106-1; eTube 287-1.
*Enzymatic Cleansing.

-------
                                                           Appendix D (Continued)
                                         PERFORMANCE AND WATER QUALITY CHARACTERISTICS
                                          ALUM-TREATED, SAND-FILTERED PRIMARY EFFLUENT.
                                                     RECIRCULATING SYSTEM, (700 psig)
Date
22 Sep 70
23 Sep 70.
24 Sep 70
25 Sep 70
26 Sep 70
27 Sep 70
28 Sep 70
FEED WATER
Re-
cov-
ery
%
65
65
65
65
65
65
65
Axial
Vel.
ft/ sec
1.29
1;29
2.58
2.58
2.58
2.58
2.58
pH
4.7
4.8
4.9
5.8
4.7
4. '6
4.9
Acid .
Feed
HC1
HC1
HC1
HC1
HC1
HC1
HC1
Temp.
°C
35
34
34
36
36
36
36
EC
5000
6000
6400
3600
3600
3900
4400
COD
mg/1
214
-.
196
-
101
- .

NH3-N
mg/1
.
9.0
-
-
-
-

Tur-
bidity
Jtu
0.3
0.6
0.4
5.8
-
5.5'
23.0
PRODUCT WATER
Flux, gal/(sq ft) (day)
1
10.9
9.8
8.6
9.4
7.0
6.9
6.3
2
5.'9
5.5
4.8
6.3
4.8
5.0
5.8
3







4







EC, /imhos/cm
1
380
450
480
280
430
460
560
2
410
470
465
220
600
660
1400
3







4







COD
mg/1
1 -4
10.1.
-
9.1
-
6.8
-

NH3-N
mg/1
1 - 4
_
0.8
-
-
-
-

un
UO

-------
                 Appendix E

    PERFORMANCE AND WATER QUALITY CHARACTERISTICS

    SECONDARY EFFLUENT, NONRECIRC ULATING SYSTEM

(700 psig, 2% Recovery, 2. 58 ft/sec Axial Velocity,  H7SOA Addition)
                                                    L*   ~r
Date
22 Jul 70
Z3 Jul 70
24 Jul 70
25 Jul 70
26 Jul 70
Z7 Jul 70
-28 Jul 70
Z9 Jul 70
30 Jul 70
31 Jul 70
1 Aug 70
Z Aug 70
3 Aug 70
4 Aug 70
5 Aug 70 .
6 Aug 70
7 Aug 70
8 Aug 70
9 Aug 70
FEED WATER
Ternt>.
°C^
31
31
3Z
30
28
30
30
31
32
32
33
31
31
28
29
30
34
34
31
PH
5.4
5.0
5.7
5.6
5.5
5.3
5.5
5.6
5.7
5,8
5.5
6.0
5.4
5.5
5.9
5.4
5.9
5.6
5.4
EC
2150
1650
1760
1750
1540
1800
1900
1845
1675
1925
1950
1925
1850
1550
1575
1750
2000
2025
1650
COD
mg/1
tm
'-
-
-.
-
-
-
-
-
-
-
-
-
• -
-
-
-
-
NH3-N
mg/1
•»
I
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Tur-
bidity
Jtu
_
7.4
12
6
5.7
4.3
6. 2
6.6
5.5
5.3
4.5
4.3
6.4
3.6
3.0
2.6
3.5
3.0
2.6
PRODUCT WATER
Flux, gal/(sq ft) (day)
1
32. 3a
23. 1
28. 4e
21.9
"18.4
18.7-
15.6
15.0
13.3
15.6
18. 1
16. 3
13.8
16,0
15. 1
18. 1
22.4
18. 6
16. 5
2
32. 3b
16.6
35. 0£
23.7
18.8
16.8
"14.9
15.0
13.8
13. 8
13.8
12.5
11.7
12.0
11.8
18. 1
21.4
17.5
16.0
3
.^___ —
32. 3C
17.8
33. 0§
23.7
18.8
16.8
14.9
15.0
14. 1
14.. 1
14. 1
13. 1
11.5
12. 2
11. 8
20. 1
23. 8
20. 2
17.5
4 '
32.3d
22. 5
24. 7
21.9
18.4
15.6
13.8
14.4
13.4
13. 0
13. 1
12.5
11.0
15.9
15.0
19.8
24.4
20.4
17.7
EC, ;umhos/crn
1
150a
"39
60e
45
48
61
52
.52
55
47
50
57
56
49
48
55
65
53
100
2
52b
35
52f*
44-
50
58
53
53
54
49
52
56
53
46
50
47
53
52
55
3
22C
28
47S
38
44
52
47
47
47
46
47
48
46
50
47
41
50
48
48
4
56d
57
56
46
50
60
55
56
57
'53
54 .
56
54
47
44
49
53
53
49
COD
mg/1
1 -4
^
-
-
-
-
-
-
-
-
-
- .
-
-
-
-
-
-
-
NH3-N
mg/1
1-4
—
-
-
-
-
«•»
-

-
-
-
-
-
-
-
-
-
-
aTube 78-11; °Tube 87-1; °Tube 93-1; dTube 85-1; CTube 82-1; 1Tube 76-H; STube 77-11

-------
                                     Appendix E (continued)
                       PERFORMANCE AND WATER QUALITY CHARACTERISTICS
                         SECONDARY EFFLUENT, NO NR EC IRC U LATINO SYSTEM
                (700 psig,  2% Recovery, 2.58 ft/sec Axial Velocity,  H2SO4 Addition)
Date
10 AugTO
11 Aug70
12 Aug70
13 Aug70
14 Aug70
15. Aug70
16 Aug70
17 AugTO
18 Aug70
19 AugTO
20 AugTO
21 Aug70
22 AugTO
23 Aug70
24 Aug70
25 Aug70
26 Aug70
27 Aug70
28 Aug70
FEED WATER
Temp.
°C
30
31
31
33
34
32
32
32
32
32
32
30
29
32
32
34
32
33
32
PH
5.4
5.4
5.4
5.6
5.4
5.4
5.2
5.4
5.3
5.0
5.0
5.5
5.7
5.7
5.3
5.3
5.3
5.0
5.3
EC
1750
1800
2000
1850
2250
2100
2800
2075
1900
1910
1800
1850
1850
1670
2100.
2050
2000
2050
2050
COD
mg/1
-
-
-
156
-
-
-
- .
55
-
-
-
22
-
92
60
90
-
NH3-N
mg/1
•-
-
-
-
-
•-
-
-
-

-
-
—
-
4.2
2.0
-
Tur-
sidity.
Jtu
3.5
1. 7
1.5
2.6
- .
2.4
1.5
4.0
4.0
3.9
4.3
5.5
4.4
3.2
3, 3
5.0
5.3
20
13
__ PRODUCT WATER
Flux, gal/(sq ft)(day)
1
16. 3
16. 2
15. 8
15.6
15. 6
15.9
15. 3
15.2
14. 4
14. 1
14. 0
14. 4
13.6
13. 8
13.5
13. 3
13.0
12. 4
12,7
2
16. 1
15.7
15. 5
15. 1
15. 0
15. 1
14. 8
14.7
13.7
13. 6
13.4
13. 6
13. 0
13. 1
13.2
13. 1
12.5
12. 2
12. 5
3
17.9
17.3
17.1
16.4
17.4
18.4
17.4
17. 1
15.7
15.3
13.5
15.7
15. 3
32. 9h
28. 8
22.2
21.7
19.3
20.4
4
18. 1
17.8
17. 6
17. 1
17.4
18. 4
17. 6
17. 1
16.0
15.8
15. 6
16. 2
15.9
16. 1
15. 2
14. 6
14. 5
13.9
14. 6
EC, ^imhos/cm
1
50
53
•60
60
72
73
61
80
63
76
57
56
52
74
54
56
49
50
4-9
2
48
49.
53
52"
58
62
59
63
128
56
54
49
48
142
51
58
55
51
53
3
52
44
51
49
58
126
82
110
92
58
54
60
82
_h
53
54
53-
50
47
4
51
50
54
62
60
52
75
71
64
52
52
51
50
49
48
51
56
54
54
COD
mg/1
1 -4
-
-
- .
-
-
-
-
-
3.9
-
-
-
0.8
-
15.6
4.4
4.3
-
NH3-N
mg/1
1 - 4
_
-
-
-
-
-
•
-
-
-
-
-
-
-
0. 5
0.35
-
Tube 188-1

-------
                                           Appendix E  (continued)
                             PERFORMANCE AND WATER QUALITY CHARACTERISTICS
                              SECONDARY EFFLUENT,  NONRECIRCULATING SYSTEM
                          (700 psig, 2% Recovery, 2. 58 ft/sec Axial Velocity, H2SO4 Addition)
Date
29 Aug 70
30 Aug 70
31 Aug 70
1 Sep 70
2 Sep 70
3 Sep 70
4 Sep 70
5 Sep 70
6 Sep 70
7 Sep 70
8 Sep 70
9 Sep 70
10 Sep 70
11 Sep 70
12 Sep 70
13 Sep 70
14 Sep 70
15 Sep 70
16 Sep 70
FEED WATER
Temp.
°C
31
32
33
33
-
32
31
31
32
32
32
32
33
33
31
30
31
30
32
PH
5.5
5.5
5.3
5.4
-
5.2
5.5
5.1
5.3
5.5
5.5
5.5
5.1
5.2
5.0
5.4
5.5
5.6
5.3
.EC
2000
2000
2050
1925
-
1750
1940
1850 .
1800
1710
1850
1925
1700
1950
1850
1825
1900
1850
1775
COD
mg/1
81
-
-
-
-
-
-
25
-
-
78
-
25
-
45
-
-
56
-
NH3-N
mg/1
\ ""
-
-
-
-
1.3
-
-
-
-
-
0.9
-
-
-
-
-
-
2.0
Tur- .
bidity
Jtu
15
13
-
4.6
- -
2.2
1.5
1.9
1.7
2.2
1.3
1. 1
1.0
1,0
1.5
1.3
1.4
2.8
9.0
PRODUCT WATER
Flux, gal/(sq ft) (day)
1
.12. 3
12. 3
11.7
11. 3
11.4
12.5
12. 3
11.7
14.7
11.9
12.2
11.4
12. 1
14,6
28. 3
-
56. 51
33.2
25. 2 •
2
11.9
11.7
12. 0
11.1
10.7
11.7
12. 1
12. 1
11.6
11. 3
11.5
11. 1
11.4
11. 6
10.9
10. 6
10.9
10. 6
10.7
3
19.8
18,7
14.4
14. 8
14.2
19.5
18.9
18.3
17.5
17.2
17.5
16.5
16.9
16.9
15.9
-
18.1
16.2
1607-
4
15. 1
14. 8
13.6
13.4
13. 1
14. 8
14. 6
14.1
13. 9
13. 6
13. 8
13.1
17. 1
13.5
13.2
1X7
13.0
12. 6
.12. .5..:
EC, ^imhos/cm
1
50
48
77
121
68
102
100
86
101
104
188
140
168
480
1200
_
841
76
130 .
2
54
53
69
62
51
52
48
54
57
59
79
55
63
55
60
63
58
78
61
3
48
48
52
49
46
47
40
45
48
50
52
50
47
46
47
—
_
61
50
4
54
52
53
52
48
57
49
51
53
52
53
56
52
52
52
54
64
74
51
COD
mg/1
1 -4
13. 3
-
-

»
_
_
1.8
fm
_
_
^m
6.2
».
0
<—
^.
0.9
-
NH3-N
mg/1
1 - 4
_
-
-

_
0.03
^
_
_
M
^_
0
_
_
—
_
mm
fm
0.1
XTube 279-1

-------
              Appendix E (continued)
PERFORMANCE AND WATER QUALITY CHARACTERISTICS
SECONDARY EFFLUENT,  NONRECIRCULATING SYSTEM
(700 psig, 2% Recovery, 2. 58 ft/ sec Axial  Velocity,
                                               H-SO. Addition)
                                                 
-------
                    Appendix E (continued)
     PERFORMANCE AND WATER QUALITY CHARACTERISTICS
      SECONDARY EFFLUENT,  NONRECIRCULATING SYSTEM
(700 psig, 2% Recovery, 2.58 ft/sec Axial Velocity, H?SOA Addition)
Date
6 Oct 70
7 Oct 70
8 Oct 70
9 Oct 70
10 Oct 70
11 Oct 70
12 Oct 70
13 Oct 70
14 Oct 70
15 Oct 70
16 Oct 70
17 Oct 70
18 Oct 70
19 Oct 70
20 Oct 70
21 Oct 70
22 Oct 70.
23 Oct 70
FEED WATER
Temp.
°C
29
30
30
30
29
29
29
30
29
29
-
20
29
29
29
29
28
27
PH
5. 3
5.4
5.8
5.4
5.9
5.5
5
5.5
5.3
5.6
5.0
5.7
5.5
5.6
5.1
5.4
6.0
5.6
EC
1750
2000
1900
1875
1850
1760
1750
1875
1700
1800
-
1950
2000
1950
1875
1775
1760
1750
COD
mg/1
78
-
80
-
36
-
-
34
-
- '
-
-
82
-
72
-
49
"
NH3-N
mg/1
\
-
-
-
-
-
-
-
-
-
-

-
-
-
-
-
-
"
Tur-
bidity
Jtu
5.5
5.6
2.3
2.6
3.4
2. 7
2.8
5.0
21
11
-
24
4.7
5.0
3.8
1.6
1.7
5.3
PRODUCT WATER
Flux, gal/(sq ft) (day)
1
16. 0
15.9
15.9
15.6
15.0
15.3
16. 1
13.6
13. 1
13.3
-
12.3
12. 5
12. 0
12.0
41.6
11.7
12.0
2
14. 4
14. 5
14. 4
14. 0
13.5
13.8
14. 1
12. 5
12.0
11.9
-
11.0
11.4
10. 8
11.9
10.5
10.6
10.9
3
16. 1
16. 3
16.0
15.8
15.4
15.6
15. 8
14. Z
13.7
10.3
-
8. 8
8.3
8.0
8.0
7.7
7.7
7.8
4
11.5
11.6
11.2
11.2
11.0
11. 1
11.1
10. 2
9.9
9.5
-
8. 8
9.2
8.9
8.9
8.6
8.6
9. 1
EC, ^.mhos/cm
1
51
.52
59
60
58
64
62
74
56
56
-
63
66
78
72
61
71
66
2
40
40
42
40
38
40
40
41
36
37
-
39
43
47
52
43
44
37
3
32
37
36
36
33
36
35
39
30
78
-
85
88
94
96
92
92
80
4
40
39
40
42
40
40
40
41
35
41
-
43
48
49
47
44
46
46
COD
mg/1
1 - 4
2. 3
-
0
-
0
-
-
5.2
-
-
-
-
0
-
1.4
-
3.8
*"
NH3-N
mg/1
1 - 4
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
"

-------
                                                    Appendix E (continued)                        (
                                        PERFORMANCE AND WATER QUALITY CHARACTERISTICS
                                         SECONDARY EFFLUENT,  NONRECIRCULATING SYSTEM
                                   (700 psig, 2% Recovery,  2. 58 ft/sec Axial Velocity, H2SO4 Addition)
Date
24 Oct 70
25 Oct 70
26 Oct 70
27 Oct 70
23 Oct 70
29 Oct 70
FEED WATER
Temp.
°C
28
29
29
29
32
29
PH
5.9
5.4
5.3
4.9
5.5

EC
1800
1850
1850
1800
1850
1700
COD
mg/1
-
54
-
66
_ .

NH3-N
mg/1
-
-
-
-
3.3

Tur-
bidity '
Jtu
9.0
-
1.5
4.5
6.3

PRODUCT WATER
Flux, gal/(sq ft) (day)
1
11.9
11.4
11.3
10.9
.10.9
11.7
2
11. 1
10.3
10. 3
10. 8
10.0
10. 6
3
7.8
7.0
7.0
6.9
6.7
7.7
4
8. 1
8.4
8. 6
8.3
8, 3
8.7
EC, ;amhos/cm
1
77
45
70
41
74
77
2
49
54
46 -
49
47
47
3
84
98
84
85
83
84
4
46
50
49
46
46
49
	 1
COD
mg/1
1 -4
_
7.9
-
1.4
-

NH3-N
mg/1
1 - 4
_.
-
-
-
-

SO

-------
                                                     Appendix -F
                              PERFORMANCE AND WATER QUALITY CHARACTERISTICS
                                 SECONDARY EFFLUENT,  RECIRCULATING SYSTEM
                            (700 psig,  2% Recovery,  2. 58 ft/sec Axial Velocity, HC1 Addition)
Date
29 Sep 70*
30 Sep 70
1 Oct 70
2 Oct 70
3 Oct 70*
4 Oct 70
5 Oct 70
6 Oct 70*
7 Oct 70*
8- Oct 70
18 Oct 70*
1 9 Oct 70
20 Oct 70
21 Oct 70*
22 Oct 70
23 Oct 70
24 Oct 70
25 Oct 70
26 Oct 70
2 7 Oct 70
28 Oct 70
i ' FEED WATER
Re-
cov-
ery
%
80
80
80
80
80
80
80
80
80
80
70
70
70
50
50
50
50
50
50
50
50
', Temp.
'[ °C
,. *•
! 36
32
36
34
34
32
30
31
32
32
33
33
32
32
30
33
32
32
32
Z9
pH
-
6.2
5.6
5.7
5.5
5.3
4.9.
4.8
-
5.6
6.3
4,3
5.7
5.8
6.4
5.3
5.3
4.5
5.0
5.1
5,4
EC
-
4000
4400
3500
2200
2800
3900
4800
5400
3700
4400
4200
3800
3900
3300
2550
2500
3600
3800
3500
3900
COD
mg/1
-
-
175
-
- '
-
119
-
.
144
-
251
-
208
- -
-
212
••
214
^
NH3-N
mg/1
• -
- -
- -
-
-

• -
. -
-
-
•-
-
-.
-
-
•-
-
-
10.5
Tur-
bidity
Jtu
-
7.6
4.3
12.5
6.3
4.1
5.6
18
13
7.5
19
8.4
5.2
11.0
35
m
5.0
4.0
3.7
8.0
7,6
PRODUCT WATER
Flux, gal/.(sq ft)(day)
1
48, 3a
24.7
10.3
4.7
4.4
4.1
3.7
21.2
15.2
8.4
15.5
7.0
5.9
21.6
6.7.
6.4
4.9
3.9
3.9
12.4C
8.4
2
74. Qb
27.2
10.3
4.4
4.4
4.1
3.7
20.8
15.9
8.6T
15.5
7.0
5.8
21.9
6.5
5.8
4. 7
3.8
3.7
3.0
3,4
3



















4



















EC, /amhos/cm
1
-
225
560
520
420
540
740
315
735
980
370
540
690
310
400
600
300
580
660
720C
760
2
-
220
535
540
500
580
670
280
810
1040
415
550
720
260
430
660
310
590
615
-
840
3



















4



















COD
mg/1
1 -4
-
-'
5.2
-
-
-
3.7
-
-
8.6
• -
5.0
-
5.3
•»
-
13.0
-.4.8
•
NH,-N
mg/1
1-4
-
-
-
-
-
-
-
-
-
-
-
-
-
-
•t
>
-
-
0.5
aTube 289-1; bTube 292-1; cTube 286-1.
*Enzymatic Cleansing.

-------
1
Accession Number
w
5
ry Subject Field & Group
05D
SELECTED WATER RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
Organization
      Envirogenics Co. ,  Division of Aerojet-General Corp. ,  El Monte, California
    Title
         REVERSE OSMOSIS RENOVATION OF PRIMARY SEWAGE
    Authorfa)
     Feuerstein,  D.  L.
                                   16
                                   Project Designation
                                                     17040 EFQ
                                       Note
 22
    Citation
 23
Descriptors (Starred First)

 *Demineralization,  *Reverse osmosis, #Sewage treatment, #Water reuse,
 Membrane processes
 25
Identifiers (Starred First)

 Organic s removal, Solids removal
 27
    Abstract
    The feasibility of renovating primary sewage effluent by the reverse osmosis process
    was investigated under a variety of conditions.  Secondary effluent was also processed
    for comparison.  High feed water velocities  were found to be necessary to maintain
    acceptable product water flux levels; at 12. 9 ft/sec, performance with primary
    effluent was comparable to secondary effluent at 2. 6 ft/sec.  Below 6.4 ft/sec, gross
    membrane fouling occurred with primary effluent.  Sizable flux restorations were
    achieved by occasional membrane  cleansing  with an enzyme-active laundry formu-
    lation and short-term depressurization of the system also  restored flux, but to a
    lesser degree.  Rejections of major pollutants were high.  Values at 2. 6 ft/sec
    averaged 94% for TDS, 94% for COD, 85% for ammonium nitrogen and 100% for
    turbidity, while values at  12. 9 ft/sec were 98% for  TDS, 98% for COD,  and  100%
    for turbidity.   Calcium sulfate deposition was experienced during the program
    because of high indigenous concentrations of the ions in the sewage used in the
    tests.  (Wilson-Envirogenics).
Abstractor
        E. M. Wilson
                              Institution
                                  Envirogenics Co. ,  El Monte, California
 WR:I02  (REV. JULY
 WRSIC
                       SEND, WITH COPY OF DOCUMENT, TO: WATER RESOURCES SCIENTIFIC INFORMATION CENTER
                                                U.S. DEPARTMENT OF THE INTERIOR
                                                WASHINGTON, O, C. 20240
                                                                       GPO: 1970 • 407 -891

-------