WATER POLLUTION CONTROL RESEARCH SERIES  WP-2O-22
        Polymers
            for
       Sewer Flow Control
rj.S. DEPARTMENT OF THE INTERIOR  FEDERAL WATER POLLUTION CONTROL ADMINISTRATION

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            WATER POLLUTION CONTROL RESEARCH SERIES


The Water Pollution Control Research Reports describe the results and
progress in the control and abatement of pollution of our Nation's Waters.
They provide a central source of information on the research, develop-
ment and demonstration activities  of the Federal Water Pollution Control
Administration, Department of the  Interior, through inhouse research and
grants and contracts with Federal, State, and local agencies, research
institutions, and industrial organizations.

Triplicate tear-out abstract cards are placed inside the back cover to
facilitate information retrieval.  Space is provided on the card for the
user's accession number and for additional keywords.  The abstracts
utilize the WRSIC system.

Water Pollution Control Research Reports will be distributed to requesters
as supplies  permit.  Requests should be sent to the Publications Office,
Department  of the Interior, Federal Water Pollution Control Administration,
Washington, D. C.  20242

Previously issued reports on the Storm & Combined Sewer Pollution Control
Program:

        WP-20-11 Problems of Combined Sewer Facilities and Overflows-
        1967.

        WP-20-15 Water Pollution Aspects of Urban Runoff.

        WP-20-18 Improved Sealants for Infiltration Control.

        WP-20-21 Selected Urban  Storm Water Runoff Abstracts.

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                  Polymers

                      for

             Sewer Flow Control
  The Development and Demonstration of the Use of
Polymers to Reduce or Eliminate Sewer Overflows by
             Flow Energy Reduction
FEDERAL WATER POLLUTION CONTROL ADMINISTRATION
           DEPARTMENT OF THE INTERIOR
                      by

              The Western Company
            2201 N. Waterview Parkway
             Richardson, Texas 75080
             Program No.  11020 DIG
             Contract No. 14-12-34
                 August, 1969

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            FWPCA Review Notice

This report has been reviewed by the Federal
Water Pollution Control Administration and
approved for publication.   Approval does not
signify that the contents necessarily reflect
the views and policies of the Federal Water
Pollution Control Administration.
                     ii

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                              ABSTRACT
       Six water-soluble polymers were investigated to determine their
effects upon aquatic flora and fauna, flow characteristics of wastewater,
and the operation of a wastewater treatment plant.

       It was found that the polymers and gels,  in the magnitudes tested,
were not toxic to bacteria, algae, or fish, and did not act as a nutrient
for algae growth.

       Based upon calculations obtained from flow test data, a maximum
flow increase of 2. 4 times the flow  prior to injection could be obtained if
a constant  head was maintained.  Laboratory  flow test data indicated that
if flow rates were held almost constant prior to and during polymer injec-
tion,  a reduction in the static head  occurred as a result of friction reduc-
tion within the  fluid.

       The most effective polymers in providing energy reduction were
Polyox Coagulant-701, WSR-301, andAP-30; however, AP-30 required
higher polymer concentrations to obtain  equivalent flow characteristics.

       In field tests on a 24-inch diameter line, it was found that poly-
mer concentrations of between 35 and 100  mg/1,  decreased frictional flow
resistance sufficiently to eliminate  surcharges of more than six feet.

       Based upon an economic analysis, the average annual cost of new
construction was approximately five times the cost  of using polymers dur-
ing peak storm-flow periods.

       This report was  submitted in fulfillment of Contract 14-12-34 be-
tween the Federal Water Pollution Control Administration and The Western
Company.
                                  iii

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                            CONTENTS


Section                          Title
       ABSTRACT ........ .........................    iii

       LIST OF TABLES ....... ...... . ............ . .  . .    vii

       LIST OF FIGURES .............................    i*

I      PROJECT CONCLUSIONS AND RECOMMENDATIONS
              Conclusions .....  ..... .................
              Recommendations .......................     ^

II     INTRODUCTION
              Purpose of Project .....   .......... . ......     ^
              Scope of Project ........................     ^
              Project Objectives .......................     9

III     LABORATORY EVALUATION OF POLYMERS
              Literature Survey .................... ...    1 1
              Laboratory Model Tests .................. . .    12
              Biological Testing of Effects of
                Polymers on Aquatic Life ..... . ............    -^
              Polymer-Nonsolvent Slurry System Study  ........    30
              Effect  of Polymers  on Sewage ...............    33

 IV     FLOW TEST EVALUATION OF POLYMERS
              Description of Flow  Test Facilities ............    47
              Flow Test Procedure. . . .............. .....    52
              Chemical and Physical Characteristics
                of Polymer-Sewage System ................    56
              Six-Inch Flow System  Test Results ...........    61
               Polymer Injection Point Test Results ...........    97
               Effects of Solid  Concentrations on Polymers ......    97

 V     FIELD TEST EVALUATION OF POLYMERS
               Large- Diameter  Sewer Field Evaluation .........    105
              Wastewater Treatment Plant Tests ............    130

 VI     ECONOMIC ANALYSIS OF POLYMER USE ..............    145

        BIBLIOGRAPHY ...... . .......................    155

 APPENDICES

 A      FLUID FRICTION REDUCING POLYMERS LITERATURE SURVEY.    159

 B      DISCUSSION OF FLUID MODIFICATION BY  POLYMERS .....    163
                                  v

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                  CONTENTS (Continued)

Section                       Title

C     DERIVATION OF GRAPHS OF PERCENT FLOW
      INCREASE VS POLYMER CONCENTRATION	   170

D     POLYMER SLURRY MIXING TECHNIQUES	   179
                                vi

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                               TABLES


Table

I      Preliminary Selection of Polymers	  li

II      Water/Polymer Concentration Used in 0. 18-Inch Diameter
       Test Line	  13

III     Biological Toxicity Test   	  25

IV     Algae Toxicity Test	  27

V      Fish Toxicity Test	  28

VI     Percent Error in Viscosity Determinations	  33

VII    Sedimentation Capability of Polymers	  39

VIII    Biochemical Oxygen Demand (BOD) of Polymers	  41

DC     Affect  of Polymers on Sludge Drying Beds	  42

X      Affect  of Polymer on Sludge Drying Beds 	  43

XI     Test Flow Parameters	  47

XII    Test Parameters and Ranges	  51

 XIII   Flow Test Polymer Concentrations  	  54

 XIV    Restriction Test Polymers	  55

 XV    Raw Sewage  Characteristics of Dallas, Texas Area	  57

 XVI     Physical and Chemical Characteristics of Polymer-Sewage
        System	  59

 XVII   Matrix of Flow Data  Used	  61

 XVIII   Test Line Manhole Instrumentation	ni

 XLX    Polymer Injection Costs--Dollars Per Hour  	H5

 XX     Sewage Sample Analyses For 24-Inch Sewer Line
        Tast Runs	125

 XXI    Results of 24-Inch Sewer Line Test Runs	  126

 XXII   Initial Test  Sites Investigated	131
                                     Vll

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                        TABLES (Continued)
Table
XXIII   Treatment Plant Slurry Components .................   132
XXIV   Treatment Plant Test -Run Sampling Times and Amounts  ....   137
XXV    Percent Removal of Applied Loading in Clarigester
       Test Series 1  ..................... .........   138
XXVI   Lewisville Sewage Treatment Plant Studies Non-Polymer
       Run .....................................   139
XXVII  Lewisville Sewage Treatment Plant Studies Polymer Run ...   139
XXVIII  Percent Removal of Applied Loading in Clarigester Test
       Series 2 ..................................   14
XXIX   Lewisville Sewage Treatment Plant Studies Non-Polymer
       Run .....................................   141
XXX    Lewisville Sewage Treatment Plant Studies Polymer Run . . .   142
XXXI   Lewisville Sewage Treatment Plant Studies Polymer Run ...   143
XXXII  Lewisville Sewage Treatment Plant Studies Non-Polymer
       Run .....................................   144
XXXIII Keen Branch Contract Bid Tabulation ................   148
XXXIV  Keen Branch Relief Sewer Costs ...................   15
XXXV  Portable Injection Plant Costs   ...................   151
XXXVI  Estimates of Polymer Use .......................   152
                                  viii

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                               FIGURES


Number                         Title                             Page

   1   Small Diameter Laboratory Flow Facility	  14

   2   Comparison of AP-30 Friction Reduction for Water
       and Sewage (9 ml/1 Settleable Solids) at 6lF in
       0. 18-Inch Test Facility		  15

   3   Comparison of D-252 Friction Reduction  for Water
       and Sewage (9 ml/1 Settleable Solids) at 6lF in
       0. 18-Inch Test Facility	  16
   4
Comparison of FR-4 Friction Reduction for Water
and Sewage (9 ml/1 Settleable Solids) at 61 F in
0. 18-Inch Test Facility	  17
   5   Comparison of J-2FP Friction Reduction for Water
       and Sewage (9 ml/1 Settleable Solids) at 6lF in
       0. 18-Inch Test Facility		  18

   6   Comparison of WSR-301 Friction Reduction for
       Water and Sewage (9 ml/1  Settleable Solids)
       at 61F in 0. 18-Inch Test Facility	  19

   7   Comparison of Polyox Coagulant-701 Friction
       Reduction for Water and Sewage (9 ml/1 Settleable
       Solids) at 61F  in 0. 18-Inch Test Facility	  20

   8   Theoretical Growth and Death Rate of Bacteria  .........  23

   9   a.  Relationship of Initial Micro-Organisms to
           Time, Based on an Arbitrary Time on the
           Theoretical Growth and Death Curve	  24
       b.  Affect of Nutrient Concentration Upon Growth
           of Bacteria	  24
       c.  Affect of Nutrient on Bacterial Count,  With
           Respect to Time  	  24

  10   Growth of Micro-Organisms in Sewage and Polymer-
       Sewage Material Including Nonsolvents Used	  29

  11   Growth of Algae in Sewage, and in Polymer-Sewage
       Media	  31

  12   Degradation of Polymers  in Slurries	  34

  13   Sludge Drying Test Beds   	  37
                                  IX

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                         FIGURES (Continued)


Number                         Title                             Page

   14  Sedimentation Capabilities of Polymer,  Based on
       Percent Increase of Net  Sewage Value  ..............  38

   15  Sedimentation Capabilities of Polymer on Settleable
       Solids ....................................  40

   16  Affects  of Polymers (at Different Concentrations)
       on Moisture Content of Sludge ....................  44

   17  Affect of Polymers (at Different Concentrations)
       on Total Solids Content of Sludge ..................  45

   18  Affect of Polymers (at Different Concentrations)
       on Volatile Solids  Content in Sludge ................  46

   19  Six-Inch Diameter Flow Test Facility ................  49

   20  Four-Inch Flow System Schematic Diagram ............  53

   21  Comparison of the Effectiveness  of Six Additives
       in Water as a Function of Temperature ...............  63

   22  Comparison of the Effectiveness  ofWSR-301 at
       200 mg/1 in Sewage as a Function of Temperature .......  64

   23  Comparison of the Effectiveness  of Polyox Coagulant-
       701 at 100 mg/1 in Sewage as a Function of Temperature ...  65

   24  WSR-301 at 200 mg/1 in  Sewage at Indicated
       Temperatures, Six-Inch  Test Facility  ...............  66

   25  Polyox  Coagulant-701 at 100  mg/1 in Sewage
       at Indicated Temperatures .......................  67
   26   AP-30 in Six- Inch Test Facility at 38F
    27   AP-30 in Six-Inch Test Facility at 70F ..............   69

    28   AP-30 in Six-Inch Test Facility at 90F ..............   70

    29   FR-4 in Six-Inch Test Facility at 38F ...............   71

    30   FR-4 in Six-Inch Test Facility at 71F  ..............   72

    31   FR-4 in Six-Inch Test Facility at 90F ...............   73
                                    x

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                        FIGURES (Continued)

Number                         Title                               Page

   32  D 252 in Six-Inch Test Facility at 38F	    74

   33  D 252 in Six-Inch Test Facility at 70F	    75

   34  D 252 in Six-Inch Test Facility at 90F	    76

   35  J-2FP in Six-Inch Test Facility at 72F	    77
                                             OT
   36  WSR-301 in Six-Inch Test Facility at 38 F in Water	
                                                         78
   37  WSR-301 in Six-Inch Test Facility at 70 F in Water	
                                   F in Water	    79
                                             OT
   38  WSR-301  in Six-Inch Test Facility at 90 F in Water	
                                                                   80
    39   WSR-301 in Six-Inch Test Facility at 38 F in
        Sewage  (3 ml/1 Settleable Solids)	    81

    40   WSR-301 in Six-Inch Test Facility at 70F
        in
Sewage (3 ml/I Settleable Solids)	    82
    41   WSR-301 in Six-Inch Test Facility at 90F
        in Sewage (3 ml /I Settleable Solids)  ..............    83

    42   WSR-301 in Six-Inch Test Facility at 38F
        in Sewage (9 ml /I Settleable Solids) ...............    84

    43   WSR-301 in Six-Inch Test Facility at 70F
        in Sewage (9 ml /I Settleable Solids) ...............    85

    44  WSR-301 in Six-Inch Test Facility at 90F
        in Sewage (9 ml /I Settleable Solids) ...............    8b

    45  Polyox Coagulant-701  in Six-Inch Test Facility
        at 38F  in Water ............................   b7

    46  Polyox Coagulant-701  in Six-Inch Test
        Facility at 73F in Water  ......................   8b
    47   Polyox Coagulant-701 in Six-Inch Test
         Facility at 90F in Water
    48   Polyox Coagulant-701 in Six-Inch Test Facility
         at 38F in Sewage (3 ml /I Settleable Solids) ..........    90

    49   Polyox Coagulant-701 in Six-Inch Test Facility
         at 73F in Sewage (3 ml /I Settleable Solids) ..........    91
                                   XI

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                        FIGURES (Continued)

Number                        Title                              Page

   50  Polyox Coagulant-701 in Six-Inch Test Facility
       at 90F in Sewage (3 ml/1 Settleable Solids)	  92

   51  Polyox Coagulant-701 in Six-Inch Test Facility
       at 38F in Sewage (9 ml/I Settleable Solids)	  93

   52  Polyox Coagulant-701 in Six-Inch Test Facility
       at 73F in Sewage (9 ml/I Settleable Solids)	  94

   53  Polyox Coagulant-701 in Six-Inch Test Facility
       at 90F in Sewage (9 ml/I Settleable Solids)	  95

   54  Injection Point Affect on Sewage System  Flow
       Constrictions	  98

   55  Percentage Flow Increase vs Sewage Concentration
       (mg/1) Polyox Coagulant-701 Polymer	100

   56  Percentage Flow Increase vs Sewage Concentration
       (mg/1) WSR-301 Polymer	101

   57  Polymer (mg/1) vs Percent Increase With a Given
       Sewage Concentration, Polyox Coagulant-701 Polymer .... 102

   58  Polymer Concentration (mg/1) vs Percentage  Flow
       Increase With Given Sewage Concentration,  WSR-
       301 Polymer	103

   59  Plan and Profile of 24-Inch  Sanitary Sewer	106

   60  Monitoring Manhole	107

   61  Water Level Recorder	108

   62  Fluorometer	109

   63  Fluorometer Recorder .	109

   64  Dye Metering Pump	 110

   65  Slurry Mixing Tank	Ill

   66  Injection Unit.	112

   67  Field Injection System With List of Parts	113

   68  Injection Manhole Cover at Manhole "A"	114
                                 xii

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                         FIGURES (Continued)

Number                        Title                            Page

   69  Units in Operation at Manhole "A"	   114

   70  Head Reduction Obtained Using 80 mg/1 of WSR-301  ....   119

   71  Hydrograph of Flow and Surcharge of Monitoring
       Manholes Before, During, and After Injecting
       Polyox Coagulant-701	   121

   72  Hydrograph of Flow and Surcharge of Monitoring
       Manholes Before, During, and After Injecting
       Polyox Coagulant-701	   123

   73  Lewisville Wastewater Treatment Plant Layout	   133

   74  Schematic of Slurry Injector System Used for
       Treatment Plant Tests	   134

   75  Sewer Line  Location Used in Cost-Benefit
       Analysis in Garland,  Texas	   146
                              xiii

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                             SECTION I

           PROJECT CONCLUSIONS AND RECOMMENDATIONS
Conclusions

       From the literature study of potential water-soluble polymers, six
candidates were selected for evaluation in the laboratory and six-inch
sewer line test facility.
Trade Name

Poly ox Coagulant-701
WSR-301
AP-30

D252

FR-4

J-2FP
 Supplier

Union Carbide
Union Carbide
Dow Chemical

Calgon Corp.

Hercules Corp.

The Western
Company
Unit Cost-H-
  $/lb.

  1.45
  0.80
  2. 15

  1.25

  1.60

  0.40
 Chemical Class

Polyethylene Oxide
Polyethylene Oxide
Copolymer (Aerylate/
  acrylamide)
Copolymer (Acrylate/
  acrylamide)
Copolymer (Acrylate/
  acrylamide)
Galactomannan
-H- The  unit costs are for less than 2,000 pound quantities, April,  1969.
Variable unit cost reductions are available on larger quantities.

       Although flow studies indicated that Polyox Coagulant-701 and
WSR-301 provide maximum friction reduction when suspended in a gelled
slurry and injected into water,  each potential polymer candidate and slurry
nonsolvent (isopropyl alcohol or cellosolve) was tested to determine what
affect each had upon bacteria,  fish, and algae.  Tests conducted indicate
that the polymers and nonsolvents are  not detrimental to bacteria growth
and, therefore, will not disrupt the biological treatment  of sewage in
wastewater treatment plants.  Tests conducted on  algae in a polymer envi-
ronment indicated that the polymers have no toxic  and only nominal nutrient
affects.  The fish bio-assay indicated that in a polymer  slurry concentra-
tion of 500 mg/1, some fish  deaths  resulted; however, flow tests indicated
that polymer slurry concentrations above 250 mg/1 provide no additional
flow benefits, and therefore, 500 mg/1 polymer concentrations would not
be required in actual pollution  control  applications.  Thus, indications
are that the use of the above polymers and polymer slurries as friction
reducers in municipal sewers will not produce fish kills  in the receiving
lake or  stream.

       After determining that the selected polymers were not toxic to
aquatic flora and fauna,  each polymer was tested in the six-inch sewer
line facility to determine flow characteristics while maintaining a constant
flow rate.  The polymers ranked in the order presented above with respect
to derived percent flow increase at a constant pressure  head (see Appendix

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C for example of how flow increase was derived).  The maximum derived
flow increase was  about 2.4 times the flow prior to injecting a polymer
slurry.  The following data indicate the  calculated percent flow increase,
based on data obtained at a constant flow rate of 300 gpm and a polymer
concentration of 200 mg/1 or ppm by weight.
       Polymer

       P. C.-701
       P. C.-701
       P.O. -701

       WSR-301
       WSR-301
       WSR-301

       AP-30
       AP-30
       AP-30

       D252
       D252
       D252

       FR-4
       FR-4
       FR-4
(1)
      Temperature
          F
          38
          73
          90

          38
          70
          90

          38
          70
          90

          38
          70
          90

          38
          71
          90
                                    Derived (2)

                                      Flow
                                    Increase
144
136
146

138
117
133

114
100
104

26
22
27

24
36
24
  Ratio of
 Final-to-
Initial Flow

   2.44
   2. 36
   2.46

   2. 38
   2. 17
   2. 33

   2. 14
   2.00
   2.04

   1. 26
   1. 22
   1.27

   1. 24
   1.36
   1.24
        J.2FP             72          12           1.12

        (1) P. C. is abbreviation for Polyox Coagulant.

        (2) Percent flow increase = Flow with Polymer - 300 gpm x  100
                                          300 gpm
        The two polyethylene oxides, WSR-301 and Polyox Coagulant-701
 were most effective in reducing friction losses; however, small-scale
 laboratory work indicated that both polymers'  friction-reduction abilities
 were reduced in a sewage media when compared with water.  Therefore,
 tests using various sewage concentrations and temperature variations
 were conducted in the six-inch test facility.  Typical results of these
 tests, conducted at a constant flow rate of 300 gpm and a polymer con-
 centration of 200 mg/1 or ppm by weight,  are presented below:

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       Polymer
   Sewage
Concentration
  ml II of
  Settleable
  Solids
WSR-301
WSR-301
WSR-301
WSR-301
WSR-301
WSR-301
P. C. -701
P. C. -701
P. C. -701
P. C. -701
P. C. -701
P. C. -701
3
3
3
9
9
9
3
3
3
9
9
9
                                Sewage
                              Temperature
                                 38
                                 70
                                 90

                                 38
                                 70
                                 90

                                 38
                                 73
                                 90

                                 38
                                 73
                                 90
           Derived
            Flow
          Increase
                              105
                               97
                               94

                              125
                              135
                              109

                              103
                              110
                              117

                              127
                              142
                              117
         Ratio of
        Final-to-
       Initial Flow

           2.05
           1.97
           1.94

           2.25
           2.35
           2.09

           2.03
           2. 10
           2. 17

           2.27
           2.42
           2. 17
       These results show that the temperature and sewage concentration
(settleable solids) should be considered prior to selecting a polymer addi-
tive.  Additional tests on these two polymers at higher sewage concentra-
tions also verify this requirement, as indicated by the following data:
       Polymer

       WSR-301
       WSR-301
       WSR-301
       WSR-301

       P. C. -701
       P. C. -701
  Sewage
 Concentration
  mlII of        Sewage
 Settleable    Temperature
  Solids         F
    46
    68
   100
   115

    44
    85
70
70
70
70

70
70
                                            Derived
                                             Flow
                                           Increase
140
 88
 79
 56

126
109
  Ratio of
 Final-to-
Initial Flow

    2.40
    1.88
    1.79
    1.56

    2.26
    2.09
       In particular,  consideration should be given to the polymer AP-30
when the above factors (temperature and settleable solids) are in the range
of 70 ml/1 and 70F.  The AP-30 polymer was found to be relatively stable
over the temperature range of 38F to 90F, and relatively unaffected by
sewage concentration;  however, the cost and higher polymer concentration
(250 mg/1 as compared with 200 mg/1 of WSR-301 and 100 mg/1 of Polyox
Coagulant-701 to achieve similar flow characteristics) required by AP-30
should be considered in its use. Also, polymer FR-4 was not affected by
sewage,  but was not as effective in providing friction reduction as polymers
shown  in the above data.

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       Polymer D252 was less effective than Polyox Coagulant-701,
WSR-301 andAP-30 in reducing frictional flow losses; however, because
of the tendency of this polymer to form a cohesive mass when dispersed
in water (although suspended in a nonsolvent gel),  it was replaced  in
performance order by FR-4, which has very similar flow characteristics.

       Polymer J-2FP required from two to five times the concentration
required for the other polymers tested.  Although this polymer costs less,
the cost difference was  not sufficient to overcome its inefficiency.

       Limited tests were conducted in which Polyox Coagulant-701,
WSR-301, AP-30, and FR-4 were used to determine what effect  a polymer
slurry injection point location had relative to relieving a flow constriction.
Test results indicated that the polymer slurry should be injected upstream
and near the pipe constriction.

       Sludge drying tests were also conducted on the selected polymers
to determine if the polymers affected drying  rate (see Table IX and Figure
16). It was found that during the first four to six days of drying,  the
moisture content  of the  sludge and polymer mixtures exceeded that of
sludge alone;  however, the moisture content at the end of 28 days was
about 10 percent  less in the mixture of sludge and polymer,  indicating
that, by using polymers, the time sludge must remain on drying beds
prior to removal and disposal can be reduced.

       The biochemical oxygen demand (BOD) of polymers has  no signif-
icant affect upon the BOD of sewage; however, an increase in  chemical
oxygen demand (COD) was measured as polymer concentration increased,
as shown in Table XVI.

       The two most effective friction reducers, the polyethylene oxides,
were water soluble and  required thorough dispersion of the individual
polymer particles during initial contact with water. The most effective
technique for obtaining  this dispersion was  the predispersion or suspen-
sion of polymers  in a gelled nonsolvent. The nonsolvents tested for toxicity
were cellosolve and isopropyl alcohol. Data indicated that, for the concen-
trations tested (maximum concentration was 500 mg/1), significant toxicity
effects were not observed. Both nonsolvents were  used in the test phases
and no advantage of either over the other was apparent;  however, cello-
solve's cost is slightly higher, $1. 12 per gallon  as compared with $0.69
per gallon  for  isopropyl alcohol.

       The nonsolvent was gelled by adding klucel H (supplied by the
Hercules Corp. at $1. 30 per pound for small quantities), which is a water-
soluble cellulose ether  powder.  The technique used in obtaining a gel is
described in Appendix D.

       After the gel was formed,  the polymer was  added slowly, about 120
pounds of polymer  each 20 minutes,  while the gel was  circulated through
the specially designed batch tank,  resulting in a  suspended polymer slurry.

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       The weight proportions generally used in making the slurry were
69. 25 percent nonsolvent,  0. 75 percent  gelling agent,  and 30.00 percent
polymer.  Slurries were also made by using 40 percent polymer; however,
this percentage was  the maximum polymer content that would remain in
suspension.  Also, the gelling agent was reduced to 0. 5 percent for a 40
percent polymer concentration.

       To obtain dispersion in water,  the slurry was injected (metered by
a valve and flow meter) into the sewage  by  an eductor which provided ex-
treme turbulence and mixing.  This method was  found to be efficient, and
the equipment required was inexpensive.  To  operate the eductor, sewage
was pumped from the sewer line through  the eductor and the sewage and
slurry were then returned to the  line.

       Tests were conducted by using the two most efficient polymers to
observe their effects upon  a 24-inch sewer  line which was frequently sur-
charged as much as  six feet.  Test results showed that a decrease  in en-
ergy or static head on the line occurred after  polymer was injected  into
the line,  although the volume  of flow carried  by the pipe increased or var-
ied only slightly.

       It should be noted that the primary purpose of the test was not to
determine the percent flow increase that could be  obtained, but to deter-
mine if each polymer provided sufficient friction reduction to eliminate
surcharged conditions.  Both of the polymers tested eliminated surcharges;
however,  lower polymer concentrations required longer time periods to
obtain the same head reduction that was obtained at the higher polymer
concentrations.

       The time required to obtain  head reduction is also dependent upon
the length of line and upstream conditions (amount of sewage accumulated
within system which, in effect,  serves as a reservoir).  It is apparent,
therefore, that potential trouble areas within a system should be monitored
and polymer injected at low concentrations to maintain the flow within the
pipe rather than delay injection  until overflow conditions are evident.  Such
a monitoring system  could  be made to operate automatically by a level de-
tection system which actuates pump motors  and valves  of the injection
equipment.

       Limited test data obtained  from investigations conducted on a
wastewater treatment plant indicated no definite improvements  in the fil-
tration and sedimentation rates. Also, no adverse effects upon the treat-
ment process were observed.

Recommendations

       It is recommended that the project's results  and the potential
polymer uses for eliminating surcharged  flow conditions be made available
to the city public works officials,  city engineers, consulting engineers,
plant engineers of industry, and various  health  officials, so that additional
applications  for polymer use will be investigated and additional full-scale
tests conducted to supplement the known data.

-------
       To avoid the expense of using a slurry to obtain hydration of the
polymer particles, investigations should be conducted into methods of
modifying polymers to permit dry feeding directly into the wastewater.

       Additional studies should be conducted to determine the degra-
dation effects of mechanical agitation,  such as occur in pumps,  upon
polymer chains (see Appendix B).  Also, the  degradation effects of polymers
flowing through pipelines over long distances should be investigated.
Polymer chain scission will result in a  reduction in the aqueous solution's
viscosity and affect its friction-reduction capability.

       The efficiency of various polymer concentrations in large-diameter
(30 inches and greater) pipes  is not known, as explained in Appendix B.
Projects  using polymers in such pipes  should be conducted to determine
characteristics of flow and efficiency.

       The applicability of polymers  to force  mains from sewage lift
stations  should be  investigated.  Results reported on this program in-
dicated that polymers could increase the capacity of pumping units by
reducing the  total system head as  a result of friction loss reductions.
Also, by maintaining the same total dynamic head on a  system, line
capacities could be  increased to prevent sewage bypasses during peak
flow periods.

       The effect of polymers on flow conditions in various conduit
cross-section configurations should be studied.

       Studies -- including full-scale sludge  drying studies  --  should
be conducted to determine what influence friction-reducing polymers
have on filter-rock biota and the activated sludge treatment process.

       The effects of various industrial wastes upon the friction reduction
capabilities  of polymers should be determined.

       An actual flow-test program  should be conducted over a period
of several months to determine the effectiveness of this technique to
prevent pollution of  natural water  systems,  and to obtain actual operational
expense of the technique.

       Additional mechanical equipment should be investigated to accom-
plish both slurry injection and dry feeding of polymer.

       Finally,  periodic investigations should be conducted to evaluate
new potential friction reducing materials and existing polymer improvements.

-------
                             SECTION II

                           INTRODUCTION
Purpose of Project

       Since 1956, when Congress enacted the Federal Water Pollution
Control Act, (amended in 1961, 1965, and  1966), an increased effort has
been made nationally to eliminate water pollution and restore our natural
water systems to a desired quality standard.  To achieve this  goal,  im-
proved and more effective methods of treating industrial and domestic
wastewater are being investigated and developed;  however, the develop-
ment, construction, and effective operation of better treating facilities
cannot prevent the continued pollution of our waters from overflows of
wastewater resulting from surcharged flow  conditions in sewage collection
systems.

       A potential method for controlling this source of pollution is  the
technique of using high molecular weight polymers to reduce frictional
resistance to flow.  This reduction lowers  the energy (static head,  in a
gravity flow system) required to drive the wastewater.   So, by maintain-
ing a constant energy level (or head), increased flow capacity can be ob-
tained with the use of such polymers in existing sewer pipe.

       This technique is applicable to both combined and separate sewer
lines during both wet- and dry-weather surcharges.

       An understanding of the extent and  magnitude of urban wastewater
overflows and surcharges has been amplified by recent studies.  Combined
sewers are used by 29 percent of the sewered population of the United
States--eight states apparently have no combined sewers in use at this
time (Reference 1).  The feasibility of separating combined sewers is com-
plicated by cost (estimated on a national basis, per capita cost is $835)
and by the areas served, i. e. ,  those areas with greatest population den-
sities and commercial activities (Reference 1).

       In those areas in which combined sewers do not present problems,
overflows resulting from ground-water infiltration and dry-weather over-
flows (caused by insufficient line capacity) produce hazards to public
health.

       The solution to the above pollution problems has been  approached
by investigating new or improved techniques and ideas  of flow containment
(control, treatment, and combinations of control and treatment).

       This report describes and presents  the results of a  Federal Water
Pollution  Control Administration sponsored research project which investi-
gated and demonstrated one method of containing and controlling flow with-
in sewer collection systems--the use of fluid flow  friction-reducing poly-
mers.  Other methods of flow control and containment currently being inves-

-------
tigated by others include a pressure sewer line within an existing combined
sewer, a system to divert stormflow to an external storage system and later
return to the system, means of modifying plumbing fixtures and system de-
sign,  means of reducing ground-water infiltration, systems of internal stor-
age and later discharge, and ways to control land use.

Scope of Project

       In the development and demonstration of the use of water-soluble
polymers for reducing frictional losses within sewer pipes, potential ad-
verse or toxic affects of both polymers and polymer nonsolvents on the
aquatic flora and fauna  of streams and treatment plants were investigated.
The selection of polymers to be investigated was  based upon a study of 1)
the literature describing their  characteristics and properties, 2) The West-
ern Company's  experience in effective use of polymers, 3) the investiga-
tions and research reported by others and 4) small-scale laboratory flow
tests.  Based on the study of available polymers and preliminary flow tests
and using specific criteria for selection, six polymers were used to deter-
mine the extent of flow  increase each caused in a sewage conveyance
system, and if each was compatible with the sewer environment.

       While determining that the selected polymers and nonsolvents were
compatible with a stream and sewage environment,  extensive flow tests
were conducted on a specially designed six-inch sewer line test facility.
These tests were conducted by using various polymers and polymer concen-
trations  in both water and sewage to determine the effects of sewage con-
centrations, as measured by settleable solids, upon the effectiveness of
the polymer and polymer concentration to reduce frictional resistence to
flow.

       Flow tests were also conducted to determine the optimum location
relative to a surcharge  for injecting polymer to eliminate various flow con-
strictions. Also,  flow tests were conducted in a large-size sewer to de-
termine actual  installation results and information relative to the flow of
wastewater in sewers containing polymers.

       As part of this installation test, equipment was designed and fabri-
cated to disperse the polymers into sewage.

       Finally, a cost-benefit analysis was made to provide an economic
measure  of the value of using  friction-reducing polymers in a sewer sys-
tem.

       The program scope also included  tests on a wastewater treatment
plant to determine what affect the polymers would have on 1) the settling
of solids,  2) the trickling filter and 3) sludge drying rates.  These tests
were conducted in a plant which contained a clarigester (mechanized
clarifier superimposed over a  mechanized digester with a  concrete tray
between the two compartments--a variation of the Imhoff tank),  a high-
rate trickling filter, a sludge  drying bed, and an oxidation lagoon (which
served as a final clarifier).

-------
Project Objectives

       The primary objectives of this project were the selection of non-
toxic, water-soluble polymers that produce reductions in frictional losses
in wastewater,  the development of an injection device and method of poly-
mer injection, the demonstration of the economic feasibility of polymer
use, and the determination of what affects the polymer and  polymer slurries
have on the  operating characteristics of a wastewater treatment plant.

       The secondary objective in selecting the best polymer for reducing
friction losses  in wastewater was to screen potential polymer candidates,
based upon friction-reduction capability,  sludge-drying  characteristics,
and toxicity to  aquatic life, such as bacteria, algae, and fish.

       The secondary objective in developing an injection device was to
minimize equipment cost, size  (for mobility) and operation and maintenance
complexity.

       The secondary objective in demonstrating the feasibility of inject-
ing polymers was to reduce the static head  on a surcharged line while min-
imizing the time required for head reduction to occur and the polymer con-
centration required to obtain the desired flow condition.

       The secondary objective of the wastewater treatment plant test was
to determine the affect polymers would have on detention time and removal
of settleable solids, as well as the affect the polymers  have on the trickl-
ing filter operation and  on sludge characteristics.

-------
                             SECTION III

                LABORATORY EVALUATION OF POLYMERS
Literature Survey

       As the first step in the program to determine the best polymer addi-
tives to use, a literature survey was conducted for the purpose of finding
determinative information that could be used in the selection process  of
potential water-soluble polymers capable of providing friction reduction
properties to sewage flow in a closed conduit.  The following  criteria were
used for selecting water-soluble polymers for evaluation.

       Friction-reduction capability.      Toxicity to biological systems.
       Solubility in water.                Flocculating and settling
       High molecular weight.             characteristics.
       Hydration (solubility) rate.         Availability from commercial
       Shear stability in flow systems.     sources.
       Storage life.                      Cost.

       Further screening was then accomplished by evaluating the appli-
cability of the additives to this  particular program,  based upon the con-
tractor's experience,  the experience of manufacturers of polymers, and
consultation with the staff of the Federal Water Pollution Control Admin-
istration.

       The  principal  sources of information used for the investigation were
Chemical Abstracts, bulletins from commercial suppliers,  and reports
written by The Western Company and others (Appendix A).

       Additives selected for further investigation as possible friction
reducers (as a result  of the literature survey) are listed in Table I.

       Application of the screening criteria to the above additives resulted
in the  following six being  selected for evaluation in the laboratory and in
the six-inch model test facility: 1) Polyox Coagulant-701, 2)  WSR-301,
3) AP-30, 4) FR-4, 5) D252, and 6)  J-2FP.  Each of these additives appeared
to have specific advantages that resulted in its selection.

        1)  Polyox Coagulant-701 has a very high molecular weight (approx-
imately 7 x 106) and produces a highly viscoelastic solution in water when
added  in relatively small quantities.  This  polymer  is basically a flocculent
which  aids  in the  sedimentation process when and if it reaches a treatment
plant.  Also, it is generally lower in price than many other polymers inves-
tigated.

        2)  WSR-301 has essentially the same advantages  as Polyox Coagu-
lant-701, except that its molecular  weight is approximately half that  of
701.  It,  too, is low in cost when compared with other polymers considered.
                                11

-------
                              TABLE I

              PRELIMINARY SELECTION OF POLYMERS
        Trade Name
   Supplier
      Chemical
     1-DSM-50C
     WSR-301
     Polyox Coagulant 701
     Polyox F.R.A.
     K-PAM
     Superfloc 16
     D-252

     AP-30

     J-2FP
     CMC-7H
     FR-4

     CMHEC-37M

     Gafloc C-61
     Gentrez AN-169
Union Carbide
Union Carbide
Union Carbide
Union Carbide
American Cyanamid
American Cyanamid
Calgon Corporation

Dow Chemical

The Western Company
Hercules Corporation
Hercules Corporation

Hercules Corporation

General Aniline
General Aniline
Polyethylene oxide
Polyethylene oxide
Polyethylene oxide
Polyethylene oxide
Poly a cry la mide
Polya cry la mide
Copolymer (acrylate/
  a cry a mide)
Copolymer (acrylate/
  acryamide)
Galactomannan
Copolymer cellulose
Copolymer (acrylate/
  acryamide)
Carboxymethylhydroxy-
  ethyl cellulose

Copolymer (methyl-
  vinyl ether/maleic
  anhydride)
        3) AP-30, based upon experience and data, had shown to be an
excellent-flow- increasing additive.

       4) FR-4,  again based upon experience, was known to behave essen-
tially the same as AP-30 in flow systems.

        5) D252, characteristically like  FR-4 and AP-30, was selected
because,  in powder form, it is manufactured in disc-like shapes, which
greatly inceases its solubility rate in water.

       6) J-2FP is low cost, has shear stability and, unlike the other five
synthetic polymer additives, it is a natural polymeric material.


Laboratory Model Tests

       After the best potential polymers were selected, each was flow
tested to determine its capabilities.  Tests were conducted in a 0. 18-inch
internal diameter tube to determine flow  behavior of sewage/polymer solu-
tions and sewage only.  The small-scale tests were inexpensive and less
time consuming than large-scale tests.   Results of these small-scale tests
provided the basis for the six-inch test line program.
                                     12

-------
       An existing small-scale flow test rig, available in The Western
Company's flow test laboratory, was utilized. This flow equipment (Figure
1) consisted of an air reservoir, a nine-gallon liquid reservoir, a temper-
ature indicator, a five-foot test section of 0. 18-inch internal diameter
tubing, a differential  pressure gage and a flow measuring device. With such
a test rig, the shear on the polymer is minimized because it was energized
with air rather than  by mechanical means (thereby creating essentially the
same condition that exists in a gravity sewer line) once the  sewage/polymer
solution is injected into the sewage flow.  This  test rig has been used for
polymer evaluation  on several in-house programs and on prior research
contracts with the Naval Ordnance Test Station (Pasadena) and the David
Taylor Model Basin. The  credibility of the test device was established
under these programs,  which therefore, instilled a high degree of confidence
in the data obtained for this program.

       Tap-water friction tests were performed by using the facility  to es-
tablish base data.  A  sewage containing  nine-miiiiliter per liter settleable
solids content was  then made up in sufficient quantity  so that sewage data
could be determined for comparison with  water data. The  sewage was "man-
ufactured" by diluting raw sludge with tap water in 35-gallon drums to give
the desired settleable solids content.

       The behavior of each selected polymer,  at different concentrations,
in tap water was  determined to establish additional base data.  Each  water-
polymer solution  was  allowed to hydrate  approximately four hours before
testing in the 0. 18-inch  rig. Polymer concentrations tested are shown in
Table II.

                              TABLE II

                   WATER/POLYMER CONCENTRATION
               USED IN  0. 18-INCH DIAMETER TEST LINE

                 Concentration                    Concentration
        Polymer	(ppm)	Polymer	(ppm)
AP-30
FR-4
D252


10
10
10


&
&
&


100
100
100


J-2FP
WSR-301
Poly ox
Coagulant
701
50
10
10


, 250 &
& 100
& 100


1250




        The above test procedure was then repeated by using a sewage con-
centration of nine-milliliter per liter settleable solids (instead of tap water)
and the polymer concentrations  shown in Table II.  This data was then
compared with the water/additive data.

        The data  obtained from the tests performed in the small-scale flow
facility are shown in Figures 2 through 7.  Test data  shown for the  tap
water/additive and the sewage/additive regimes  compare flow behavior
in each system.
                                13

-------
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-------
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Figure 2.  Comparison of AP-30 Friction Reduction for Water and Sewage

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                              15

-------
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Figure 3.  Comparison of D-2^2 Friction Reduction for Water and Sewage
          (9 ml/1 Settleable Solids) at 6lF in 0. 18-Inch Test Facility.
                                   16

-------
     1000
                        VELOCITY  , FEET /SEC
                                                                 100
Figure 4.  Comparison of FR-4 Friction Reduction for Water and Sewage
          (9 ml/1 Settleable Solids) at 61 F in 0. 18-Inch Test Facility.
                              17

-------
       1000
                                      10
                         VELOCITY, FEET/SEC
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Figure 5.  Comparison of J-2FP Friction Reduction for Water and Sewage
          (9 ml/1 Settleable Solids) at 6lF in 0. 18-Inch Test Facility.
                                   18

-------
       1000
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                              VELOCITY , FEET / SEC.
Figure 6.  Comparison of WSR-301 Friction Reduction for Water and Sewage
          (9  ml/1 Settleable Solids) at 6lF in 0. 18-Inch Test Facility.
                               '

-------
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Figure 7.  Comparison of Polyox Coagulant-701 Friction Reduction for
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          0. 18-Inch Test Facility.
                                 ;:

-------
       The sewage behaved Theologically (flow and viscosity), the same
as water without additives.  Consequently, a pressure drop per unit length
   A P  \ versus velocity (V) plot of the data could be used to determine
    L   j the affect of sewage on the  additive as far as its friction-reduc-
tion ability was concerned.

       A comparison of water/polymer with sewage/polymer data for AP-
30, D252, and FR-4 (Figures 2,  3 and 4) showed no interference by the
sewage on friction-reduction ability of the polymers.  Since these three
additives are aery late /acrylamide type co-polymers,  it would be expected
that if one was not affected, the others would not be.

       J-2FP, WSR-301 and Polyox Coagulant-701 showed a polymer/sew-
age interaction in the small-scale testing which was, to different degrees,
slightly deleterious to their friction-reduction effect. Figures 5, 6 and 7
show the friction comparison of water/polymer with sewage/polymer data
for J-2FP, WSR-301 and Polyox Coagulant 701, respectively;  however, the
deleterious effect of the  sewage on friction reduction remains constant as
the polymer concentration is increased; thus, it was  concluded that a con-
stant amount of the polymer was affected regardless of  polymer concentra-
tion.


Biological Testing of Affects of Polymers on Aquatic Life

       While flow tests  were being conducted on the six selected polymers,
toxicity and other affects upon bacteria, algae,  and fish were determined
by using standard methods  (or accepted methods  in specific instances).

        Purpose of Tests. Since sewage is biologically decomposed in sew-
age treatment plants, it  is  desirable that  the presence of polymers at vary-
ing concentrations not be detrimental to the bacteria  in the collection and
treatment systems. Therefore, toxicity tests (of polymers and polymer
slurries toward sewer organism) were started early in the program.

        Storm water from heavy rain results in surcharges and/or overflows
in separate as well as combined sewers,  as does infiltration,  illegal  con-
nections, and  insufficient  line capacity.  This wastewater is often com-
pletely or partially bypassed at the treatment plant and directly discharged
into a lake or stream.  The  use of polymer injection to alleviate the sur-
charge condition in sewers must not extensively contribute to the pollution
problems of these discharges, or cause fish kills, bacterial death or algae
blooms. Therefore, polymers and polymer slurries affect upon algae and
fish were also investigated.

        Bacteria Test and Analysis  Procedure. Random seed samples of raw
sewage were taken from the Rowlett Creek sewage treatment plant, located
in the City of Garland, Texas. A portion of the raw sewage was diluted
 1:100 with distilled water.  From this dilution, 1 milliliter was transferred
to a sterilized petri dish containing 10 milliliters of  nutrient agar. Three
 samples were  prepared in this manner for a control group, then incubated
at 37C for 24 hours. After 24 hours,  a bacterial plate count was  made.
 Subsequent counts were made at selected time intervals to determine

                               21

-------
bacterial growth and death pattern in the sewage,  which was controlled as
described below for the polymer-sewage mixtures.

       To evaluate the toxic effect of polymers  on bacteria,  two 200-
milliliter Erlenmeyer flasks were filled with 100 milliliters of sewage, and
a polymer added to achieve the desired polymer  concentration.  The polymer
concentrations were evaluated at 100 and 500 milligrams per liter,  which
gave an upper and lower limit for evaluation.  The tests were conducted at
2 C and 29. 5C in the  constant-temperature bath.  The Erlenmeyer flasks,
containing polymer and sewage, were placed in  the constant temperature
bath and agitated at the rate  of 85 strokes per minute to simulate movement
in a sewer line.  At fixed intervals after initial mixing, 1-milliliter samples
were withdrawn from the flask and 1:100 dilutions  were made with distilled
water.  Samples of 1-milliliter were withdrawn from the 1:100 dilution and
transferred to the nutrient agar in the sterilized  petri dish, then incubated.
A bacterial count was conducted after  24 hours,  repeating the procedure for
the control group.

       Figure 8 shows the theoretical bacterial  growth and death cycle in a
constant nutrient substrate.  To properly evaluate the toxic effect of polymer
for bacteria,  an initial point  was chosen on the  growth and death curve (Fig-
ure 9a) to represent the initial raw sewage bacterial count which then became
the 100 percent count  of the  micro-organisms.  At each of the selected time
periods, an increase or decrease in bacterial count was  expressed as  a per-
centage deviation from the initial count.  A fixed nutrient condition was
chosen as a control parameter,  since changes in nutrient concentration
(Figure 9b) affect the number of micro-organisms.  With  the initial nutrient
fixed for the  incubation period,  any growth or death of bacteria is reason-
ably dependent upon the sewage and polymer or nonsolvent added.

       Figure 9c indicates the theoretical relationship of time with bacterial
count (i. e. ,  that expected from  the growth testing since the  added polymer
is a nutrient).  The "sewage" curve indicates the  growth of bacteria feeding
on a sewage  as the available nutrient  and their  subsequent decline as the
nutrients are  consumed. During the time period when the bacterial death
occurs on the sewage curve,  the bacterial count is increased slightly  on the
polymer and sewage curve and does not diminish as rapidly due to lack of
nutrients.

       The bacterial counts were made by using a Quebec Colony Counter
on the petri dishes containing the sewage seeding or polymer and sewage
seeding.  Standard methods were used in counting.  The tabulations of all
data can be found in Table III.

       Algae Test and  Analysis  Procedure. Water containing algae was
obtained from the sludge bed  drainage  pond at the  Duck Creek Sewage Treat-
ment Plant (located near Garland,  Texas).  Three 200-milliliter, sterilized
Erlenmeyer flasks were filled to the 100-milliliter mark with this  pond water.
These three flasks were used as a control group.  Two additional 200 milli-
liter Erlenmeyer flasks were filled to the 100-milliliter mark with the pond
                                      22

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                                                             CONSTANT

                                                             RATE OF

                                                             GROWTH
u>
CO

CO

<
O

%

6
oc.
O
                    O



                    
-------

                                   TIME
 Fiaure 9a.  Relatiorship of Initial Micro-Organ isms to Time,  c-ased on
             an Arbitrary Time or, the Theoretical  Growth and Death Curve.
     y.
g
   il
                           CONCENTRATION of NUTRIENT
  Figure 9b.  Affect of Nutrient Concentration Upon Growth of Bacteria.
                                                             POLYMER and
                                                             SEWAGE
                                           \
     i
                                             \
                                                           SEWAGE
                                    TIME-
Figure 9c. Affect of Nutrient on Bacterial Count, With Respect to Time.
                                      24

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                         TABLE III
                 BIOLOGICAL TOXIC ITY TEST
Polymer
Concentration
Additive (mg/1)
Average Bacterial Count by Percent
Number of Hours from Start
0 3 6 9 24 48 72
oTenBP'
C/ F
None
AP-30
WSR-701
WSR-301
FR-4
J-2FP
D-252
-H-AP-30
-H-WSR-701
-H-WSR-301
-H-FR-4
-H-J-2FP
-H-D-252
None
AP-30
WSR-701
WSR-301
FR-4
J-2FP
D-252
-H-AP-30
+KWSR-701
-H-WSR-301
-H-FR-4
-H-J-2FP
H+D-252
None
AP-30
WSR-701
WSR-301
FR-4
J-2FP
D-252
-H-AP-30
-H-WSR-701
H-WSR-301
-H-FR-4
-H-J-2FP
-H-D-252
	
100
100
100
100
100
100
100
100
100
100
100
100
_  fm
500
500
500
500
500
500
500
500
500
500
500
500
_._
500
500
500
500
500
500
500
500
500
500
500
500
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
204
190
179
202
178
167
162
214
199
220
137
165
148
120
154
136
148
152
158
153
178
165
161
141
139
203
89
89
87
98
82
75
80
77
86
74
89
69
74
163
142
142
170
155
170
135
168
130
158
158
117
116
157
184
139
145
134
105
140
84
233
166
144
122
175
63
62
21
67
59
70
61
63
68
46
54
50
41
201
137
136
122
125
140
130
140
167
153
210
141
155
166
166
134
128
114
124
121
117
142
156
120
116
164
59
66
55
59
62
68
65
54
53
44
60
56
68
165
99
123
115
137
112
140
147
160
168
179
103
97
40
158
94
78
108
164
107
104
86
81
65
122
116
63
121
91
66
60
81
73
87
114
81
94
67
106
88
147
95
117
116
98
104
151
130
152
125
80
90
18
60
25
22
103
53
58
148
112
85
131
54
175
33
66
81
72
72
70
71
83
87
82
68
56
68
124
98
112
75
94
81
90
141
100
107
117
87
90
18
46
14
12
76
52
27
120
77
90
59
55
92
69
73
66
72
62
67
72
59
56
77
62
80
52
20.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
29.5/85
2/35.6
2/35.6
2/35.6
2/35.6
2/35.6
2/35.6
2/35.6
2/35.6
2/35.6
2/35.6
2/35.6
2/35.6
2/35.6
agent,  each by weight).
                               25

-------
water, and a polymer was added to achieve the desired concentration. The
flasks were then placed in a constant-temperature bath maintained between
23C and 26C (this temperature range approximated that of the pond where
the samples were obtained).  A 450-foot-candle light source was placed
above  the bath to maintain constant light intensity  for photosynthesis. At
selected time intervals,  1-milliliter samples were withdrawn from the Erlen-
meyer  flask and transferred to a microscopic slide for algae counting under
a microscope  equipped with a Whipple eye piece.   Five random locations
on the grid in the eye piece were counted and the results averaged.

        The algae growth testing was  conducted at two. polymer concen-
trations (100 and 500 milligrams per liter) which provided an adequate
range  of conditions.  The initial algae count of the pond water was con-
sidered to be  100 percent with subsequent algae counts, at specific time
intervals, reported as deviations from the initial count and expressed as
a percentage. An increase or decrease in algae count from the control group
would  indicate the nutrient or the toxicity affect of polymers on algae (Ref-
erence 3).   Data from the testing of algae can be found in Table IV.  Tests
were also conducted  on the nonsolvents  to be used in producing slurries.

        Fish Test and Analysis Procedure. The study of toxicity of polymers
on fish was conducted with a test matrix involving  three control groups for
each polymer concentration.   Tests were conducted at three polymer con-
centrations (50,  100  and 500 milligrams  per liter),  by using three  samples
at each polymer concentration.

       A plastic swimming pool, five feet in diameter,  served as  a con-
stant temperature bath, and temperature  control was maintained by the
cooling coils  of a refrigeration unit.  The temperature range was 20C to
22C,  which approximated that of local pond water from which the guppies
used were obtained.  Each sample unit contained five guppies in 2. 25 liters
of the  same pond water in which they were kept.

       Toxicity  effects of each polymer  on the fish were evaluated by
counting the fish still living at selected time intervals in the control group
and in the test groups containing the  polymers and  the nonsolvents. The
results were then reported  as a percentage of fish remaining based on initial
number of fish in the  control group. Tabulated data  can be found in Table V.

       Bacteria  Data  Evaluation. In Figure  10, the  combined data  taken
from Table III  for the  investigating period, indicates that minimal bacterial
growth occurred  in the sewage control at 48 hours.   During this same test
period higher counts of bacteria were  obtained in the polymer-sewage mix-
tures.  The data  indicates that the bacteria  were using the polymer as a
food source.   Lower polymer  concentrations influenced growth to the extent
that the total quantity of food available was reduced.  Temperature reduc-
tions simply lowered bacteriological activity, thereby reducing growth.
                                     26

-------
                             TABLE IV
                      ALGAE TOXICITY TEST
Polymer
//-_ ii \
Additive (mg/1)
None
AP-30
WSR-701
WSR-301
FR-4
J-2FP
D-252
AP-30
WSR-701
WSR-301
FR-4
J-2FP
S-252
Cellosolve
Cellosolve
Isopropanol
Isopropanol
  
100
100
100
100
100
100
500
500
500
500
500
500
100
500
100
500
Average Algae Count by Percent

0
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
Number of Hours from Start
6
212.7
207. 1
321.4
150. 0
135.7
185.7
207. 1
185.7
157. 1
285.7
221.4
164.3
244.4
122.2
111. 1
133.3
111. 1
9
160. 3
128.6
150. 0
121.4
78.6
92.8
114. 3
114.3
164. 3
135.7
71.4
128.6
211. 1
133.3
100.0
77.8
66.7
24
136. 5
64.3
92.8
71.4
64. 3
100. 0
78.6
100. 0
221.4
285.7
221.4
150. 0
133. 3
100. 0
88.9
188.9
77.8
48
85.7
78.6
42.8
57. 1
57. 1
142. 8
42.8
64.3
200.0
1 07 . 1
71.4
57. 1
66.7
155.6
155.6
44.4
111. 1
72
86.8
71.4
114.3
50.0
57.1
114.3
35.7
71.4
164.3
64.3
28.6
57.1
77.8
100.0
100.0
33.3
44.4
H- Concentration
                             27

-------
                              TABLE V




                       FISH TOXICITY TEST
Additive
None
AP-30
WSR-701
WSR-301
FR-4
J-2FP
D-252
None
AP-30
WSR-701
WSR-301
FR-4
J-2FP
D-252
None
AP-30
WSR-701
WSR-301
FR-4
J-2FP
D-252
None
Cellosolve
Cellosolve
Cellosolve
Isopropanol
Isopropanol
Isopropanol
Polymer
Conc.-tt
(mg/1)
Averaae Fish Count by

0
100
50 100
50 100
50 100
50 100
50 100
50 100
--- 100
100 100
100 100
100 100
100 100
100 100
100 100
--- 100
500 100
500 100
500 100
500 100
500 100
500 100
--- 100
50 100
100 100
500 100
50 100
100 100
500 100

6
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
Time
12
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
87
100
100
100
100
100
93
100
100
100
100
100
100
Percentaae Remainina
(Number of Hours from Start)
24
100
93
100
100
93
100
100
100
100
100
100
100
100
100
100
67
93
100
87
100
100
87
100
100
100
100
100
100
30
100
93
100
100
87
100
100
100
100
100
100
100
100
100
100
67
93
100
87
100
93
87
100
93
100
100
100
87
36
100
93
100
100
87
100
100
100
100
100
100
100
100
100
100
67
93
100
87
100
93
87
100
93
100
100
100
87
48
96
93
93
100
87
100
100
100
100
100
100
100
100
100
100
60
87
100
87
100
93
87
100
93
100
100
100
87
54
96
87
93
100
87
100
100
100
100
100
100
100
100
100
100
60
87
100
87
100
80
87
100
93
100
100
100
80
60
96
87
93
93
87
100
100
100
100
100
100
100
100
100
100
60
87
100
87
100
80
87
100
93
100
100
100
80
72
96
87
93
93
87
93
100
93
100
100
100
100
100
100
93
60
87
100
87
100
80
87
100
93
93
100
100
80
-H- Concentration
                                    28

-------
o
         I  i
         ID
         M,
         to

         i
         w
          to
          hi
          c

          0)


          ;. ,

          fil
          I/,

          (0

          CO

          6
          w
'Sewage only



Upper limit



Average



Lower limit
for all data at each time

  for sewage  fc polymer
IU
8
O
L*
O
i
4H
O
>.
4*
-H
+J
c
fO
.5
\,^    	 	 __
- 80


- 60

- 40


- 20
4 8 \2 16 20 2'. 28 32 36 40 44 4-8 52 56 60 64 68 72
                                             Hours After Start of Test

             Figure  10.  Growth of Micro-Organisms in Sewage and Polymer-Sewage Material Including

                        Nonsolvents Used.

-------
        Comparative tests were made between polymers in the powdered
form and in the slurry form.  The nonsolvents,  cellosolve and isopropyl
alcohol, used in the slurried polymers proved to be  generally nontoxic to
bacteria in the magnitudes used.  The slurry consisted of polymer (40 per-
cent by weight),  nonsolvent (59. 5 percent by weight) and gelling agent
(0. 5 percent by weight).

        The efficiency of sewage degradation by micro-organisms remains
essentially unaltered when polymers are present.  The tests proved that the
polymers evaluated are nontoxic  to the bacteria under the conditions  of the
tests.   Thus, polymer injection into a sewer system should not be detrimen-
tal to the micro-biological treatment process in a sewer treatment plant.

        Algae Data Evaluation.  The curves in Figure 11 are taken from the
combined data  in Table IV.  The trend  is similar to that shown in Figure 10.
There is only a slight deviation of the average  combined data curve from the
sewage curve;  therefore, the polymers tested have no toxic or nutrient affect
on algae under the concentrations and conditions tested.

        Since the polymers tested are nontoxic  and do not serve as  a  nutrient
to algae, polymer injection into a surcharged sewer should have no undesir-
able affect upon  algae in a lagoon, lake or stream after  discharge as  the ef-
fluent  from a sewage treatment plant.  Also, if polymer injections are used
in storm sewers, the discharge should have no appreciable affect on  the
algae of the receiving waters.

        Fish Data Evaluation.  The data in Table V indicates a non-toxic
affect  of the polymers tested upon guppies used as subjects in the fish
evaluation.  There was a slight lowering in the percentage of fish remaining
at a  polymer concentration  of 500 milligrams per liter; however,  these values
are within  the realm of probability of natural deaths for the fish although it
appeared that some of the polymers had a tendency to clog the gills.

        Data for nonsolvents (cellosolve  and isopropyl alcohol) used in the
test  program were included because polymer injection will usually be con-
ducted by using slurries.  The largest percentage, by weight, of a  slurry
consists of a nonsolvent, and the possibility exists that the nonsolvent
might have deleterious affects upon marine life;  however,  data acquired
during the  environmental study show no appreciable toxic affects upon fish
as the  result of nonsolvents applicable to this  program under the conditions
of the tests.  Therefore, the use of polymers as friction reducers in sanitary
sewers  will not contribute  indirectly to lake or stream pollution by  having a
toxic affect upon fish life.


Polymer-Nonsolvent Slurry System Study

        Slurry Formation.  Water-soluble polymers dissolve readily in water;
however, the solvation process involves thoroughly  dispersing the  individ-
ual resin particles during the first two or three  minutes.  As the polymer
surfaces begin absorbing the solvent,  they become very  cohesive.  Upon
contact of the particles during this wet-out period, an agglomerate is formed
                                      30

-------
                                   oewage only

                                   Upper limit

                                   Average

                                   Lower limit
all data at each time
for sewage and polymers
                          Hours After Start of Test

Figure  11.  Growth of Algae in Sewage, and in Polymer-Sewage Media.

-------
and prolonged agitation is required to dissolve the agglomerate or gell-like
mass.  By keeping the particles separated, the particle surface quickly dis-
solves, producing a protective envelope or film of viscous solution around
the particle.   The particle solvation proceeds with the solution viscosity
increasing rapidly.

       Since dispersion is necessary to enable the resin particles to be
quickly and completely dissolved, a method is required to maintain polymer
dispersion for the solvation process.  Predispersion, of polymers  in a non-
solvent that has been gelled,  meets this criteria.  Cellosolve (ethylene
glycol monoethyl ether) gelled with a cellulose ether is an effective system
for slurry formation of AP-30,  FR-4 and J-2FP.

       Anhydrous isopropanol gelled with a cellulose ether has shown to be
an effective system for slurry formation of polyethylene oxides (WSR-301
and Polyox Coagulant-701.

       The dispersion of polymers in slurry form can be prepared readily,
stored for long periods  and used as needed.  These slurries, when added
to water,  form aqueous systems quickly and with minimum agitation,  and
are useful for large-scale operations where speed is  necessary in getting
the polymers dissolved quickly.

       One polymer, D-252,  would not lend itself to predispersion in a
gelled nonsolvent.  The incompatibility was due to a double convex particle
shape which prevented a 40-percent polymer loading in the gelled nonsolvent
(cellosolve).  Settling  occurred in this  suspension and the slurry was not
easily pumped.

       Slurry Degradation.  Since polymers are known to degrade  in aqueous
systems,  there existed a possibility that degradation might occur in the
slurry system.

       Degradation implies polymer chain scission  and is reflected by a
reduction in molecular weight of the polymers.  Polymer chain cleavage is
effected by mechanical agitation,  by ultraviolet light, by bacteriological
action, and by chemical oxidation due to dissolved air.

       Reduction of molecular weight due to polymer chain scission is
evaluated by measuring a reduction in the aqueous solution's  viscosity.

       In this study a weighed quantity of the desired polymer in slurry form
was added to a weighed quantity of tap water to give a  concentration of poly-
mer at 500 ppm.  This  concentration of polymer was  chosen, since the time
required to measure the relative viscosity was less than three minutes per
sample, which minimized experimental error due to degradation in the aque-
ous system.  At the end of the first 24 hours of combined materials,  the
polyacrylamides degraded by 0. 52 percent and polyethylene oxides degraded
by 4.  1 percent.   Thus,  a measure  of the relative viscosity of a freshly made
aqueous polymer  solution from a slurry would show if cleavage of polymer
chain or degradation occurred to the polymer while stored in slurry form.
                                      32

-------
       In the evaluation procedure, a 12-milliliter sample of the polymer
test solution was introduced into a Ubbelohde Viscometer and the time of
passage for this quantity of aqueous polymer solution obtained.  The ex-
periment was conducted in a constant temperature bath of 75F, with the
test solution being equilibrated prior to the time measurement was taken
in the Ubbelohde Viscometer.  The relative viscosity measurements  ob-
tained were defined as the ratio of time for the aqueous polymer solution
(12  milliliter) to flow to the time for tap water (12 milliliter) to flow in the
Ubbelohde Viscometer.  The experimental error expected for relative vis-
cosity measurements in the Ubbelohde Viscometer was - 10 percent. From
Figure 12,  the plot of relative viscosity versus time implies no appreciable
degradation occurring to polymers in a slurry form.  The percents of error
based on the average of relative viscosity measurements (shown in Table
VI), taken  over a 50-day period for AP-30,  FR-4, Polyox Coagulant-701
and WSR-301,  were recorded as 6.3 percent, 2.9 percent, 1.4 percent,
7. 2 percent and 2. 9 percent, respectively.  This range is well within the
expected experimental error of relative viscosity measurement.
                               TABLE VI

            PERCENT ERROR IN VISCOSITY DETERMINATIONS
Relative
Polymer Viscosity
AP-30
FR-4
Polyox
Coagulant-
701
WSR-301
3.502
3.708
2. 118
2.770
3.013
2.908
2.290
2.082
1.852
1.851
1.805
1.710
Average Average
Relative Standard
Viscosity Deviation Deviation
3.443 -0.
-0.
+0.
2.897 +0.
-0.
-0.
2.0746 -0.
-0.
+0.
1.7886 -0.
-0.
+0.
0594 .216
2654
3246
1270 .0847
1160
0110
2154 .1485
0074
2226
0624 .0525
0164
0786
Precision
6.3
2.9
7.2
2.9
Effect of Polymers on Sewage

       Purpose of Tests. Evaluation of polymer affects on sewage was
enabled by measurements of those parameters that produced the most sig-
nificant information,  e.g., dissolved oxygen, biochemical oxygen demand,
                               33

-------

-------
change in settleable solids, percent moisture change in sludge drying beds,
total solids in sludge drying beds, and volatile solids  in sludge drying beds.

       Sedimentation Test and Analysis Procedure. Information, obtained
from suppliers of the six selected polymers indicated that each polymer had
the ability to settle inorganic  and organic material--they all exhibited a
varying ionic character that was pH dependent, which allowed them to be
generally classified as polyelectrolytes.   (Note:  The  exact mechanism by
which the polymers agglomerate the suspended material is not known but,
once formed, it should exhibit a strong bond  and be quickly and irreversibly
formed).

       To determine the  increase in sedimentation by polymer addition, a
1-litter graduated cylinder was filled to the mark with raw sewage (from the
Rowlett Creek sewage treatment plant) for use as a control.  At the same
time,  three  1-liter graduated cylinders were filled with the raw sewage
and enough polymer was  added (by weight) to obtain  polymer concentrations
of 100, 200 and 500  milligrams  per liter.  These samples were used to det-
ermine the magnitude of settling of the polymers, so that sewage settling
could be  determined.

       A standard two-hour settling time was used for each graduated
cylinder containing sewage, polymer/sewage and polymer/distilled water.
Then, all but 100 milliliters were decanted from each cylinder, leaving
essentially the settleable solids, and some water to be evaporated on a
water bath.  After evaporation to dryness, the solids were weighed and the
milligrams per liter of settleable solids determined.

       For analysis, the amount of polymer that settled in distilled water
was subtracted from the amount  of sewage and polymer that settled.  This
difference left the net quantity of sewage  settled by  the polymer.  This
quantity was then divided by the quantity  of sewage  that settled in the
control, with the results expressed as a percentage.  Values  greater than
100 percent indicated an increase in sedimentation due to the  addition of
polymers.

       Biochemical Oxygen Demand (BOD) Test and Analysis  Procedure.
Standard  Methods (Reference 2)  were used to determine biochemical oxygen
demand (BOD) and dissolved oxygen (DO).

       It has been shown that the polymers,  being carbonaceous organic
materials,  are usable as a source of food  by  micro-organisms  and, there-
fore, exerted an oxygen demand. Adequate DO is required for aerobic deg-
radation  of sewage, whether it takes  place in sewer  lines, in sewage treat-
ment plants, or in effluent receiving waters.

       Since polymers are degraded by both chemical oxidation and bacte-
rological action,  measurement of the DO will allow establishment of the
oxygen requirements for polymers.  By using  500 milligrams per liter con-
centrations, which are above  the upper limit  to be used, an extreme limit
of oxygen use by the polymers was provided.
                                35

-------
       The standard BOD provides data for measurement of the stabilization
of the oxidizable organic polymer systems.

       Sludge Test and Analysis Procedure. A principal by product of sewage
treatment is sludge.  One method of disposal is to pump the digested sludge
onto drying beds where it dries by drainage and/or evaporation.  Since the
polymer agglomerates the solid material in sewage, the resulting treated
sludge may contain some of the polymer following an injection into a sewer
line  or prior to a plant function. By measuring the moisture content,  the total
solids,  and the volatile solids, effects of the polymer on  the sludge drying
beds may be determined.  Figure 13 shows  the schematic arrangement and
sizes of the test bed system used  in evaluation of polymer affects on sludge
drying.

       The drying bed, constructed of 2-inch by 12-inch lumber, was placed
on an existing underdrained sludge bed to a depth of 2 inches. A 55-gallon
barrel, fitted with a quick-closing/opening valve, was used as a mixing
chamber.  Enough polymer to prepare a 50- and a  200-milligram-per-liter
concentration was added to 40 gallons of sludge,  mixed and then drained
onto one bed of the form.  Four test beds of raw sludge were used as con-
trols plus  one bed for each polymer at each of the concentrations. In addi-
tion, a full-size sludge bed was filled with the same sludge at the same
time the test beds were filled.  Over  a 28-day test period, 12 samples were
taken from each of the test beds at specific time intervals.  The moisture
content was determined (by weight difference, before and  after it was dried)
and expressed  as  percent moisture.  Other samples of 100-milliliter size
were evaporated over a water bath according to standard methods (Reference
2) for total solids determination.   The total solids samples were also used
in determining  the total volatile solids.

       Sedimentation Data Evaluation.  In Figure  14,  the combined sedimen-
tation data from Table VII for all polymers at varying concentrations indicate
sedimentation capability; however, it should be noted that the percentage
increase in sedimentation is dependent upon increases in polymer concen-
tration. Figure 15 shows the order of sedimentation ability for each polymer
at different concentrations.

       Some loss  of polymer may occur following injection into a sewer due
to sedimentation;  however,  since  injection will only  be done when the sewer
is surcharged,  turbulence will keep the solids in suspension,  and most of
the polymer injected will be available for energy reduction and for the ac-
companying possible  increase in settling of solids in the treatment plant.

       BOD Data  Evaluation. A maximum polymer concentration of 500  mil-
ligrams per liter was  chosen for the BOD determination because magnitude
was  not of any  great importance with respect to the sewage BOD (smaller
concentrations  of polymers would be even of less importance in the  sewer
systems).

       Based on the standard BOD test, Table VTII indicates that the bio-
chemical oxygen demand for all polymers is 1. 56 milligrams per liter for a
polymer concentration of 500 milligrams per liter. Essentially, this  value
                                      36

-------
r
"o
 I
OJ
	 	  iz-o 	 
WSR-301

2OO mg/l
FR-4

200mg/l
WSR-701

50mg/l
SEWAGE
SLUDGE
ONLY N0.4
SEWAGE
SLUDGE
ONLY No. 1
WSR-701

200mg/l
D-252

50mg/l
FR-4

50 mg/l
i
D-252

200 mg/ 1
AP-30

50mg/l
SEWAGE
SLUDGE
ONLY NO. 3
AP-30

200 mg/l
J-2FP

50 mg/l
SEWAGE
SLUDGE
ONLY NO. 2
J-2FP

200 mg/l
WSR-701

50mg/|
                 Figure 13.  Sludge Drying Test Beds.

-------
OJ
00
         JX
         "c
         o
          0>
          en
          (0
          
          (1)
          o
         T3
          0}
          w
          (0
         CO
O
-4
M
(0

s
Q)

-c-4
T3
(D
CO
-M
C

-------
                             TABLE VII



             SEDIMENTATION CAPABILITY OF POLYMERS
Additive
AP-30
AP-30
AP-30
AP-30
FR-4
FR-4
FR-4
FR-4
D-252
D-252
D-252
D-252
J-2FP
J-2FP
J-2FP
J-2FP
WSR-301
WSR-301
WSR-301
WSR-301
WSR-701
WSR-701
WSR-701
WSR-701
Polymer
Cone. +
(mg/1)
0
100
200
500
0
100
200
500
0
100
200
500
0
100
200
500
0
100
200
500
0
100
200
500
Setteable Solids (mg/1
Sewage
&
Polymer
119
172
216
269
551
730
642
886
89
144
195
367
122
163
204
399
86
162
236
448
276
_ 
295
368
Polymer
0
9
20
34
0
68
145
265
0
50
91
214
0
46
45
69
0
49
126
313
0
	
41
43
Net
Sewage
119
163
196
235
551
662
497
621
89
94
104
153
122
117
159
330
86
113
110
135
276
	
254
325
)
Percent
Net Sewage
Only Results
100
137
165
197
100
120
90
113
100
106
117
172
100
96
130
270
100
131
128
157
100
	
92
118
-H- Concentration
                             39

-------
0)
: '
. '
10
: -
,,,
(31
m

&
(U
Q]
: :

.
o

>-
03
01
to
I

'

. I
I 
10
' '
 :
0)
CO

1 ^

a

.
QJ
P
           50
100
zoo
  I
500
O  AP-30

A  FR-4

O.D-Z52

D  J-ZFP

V  WSR-301

X  WSR-701

    400
150
                             Polymer Concentration, ppm

        Figure 15.  Sedimentation Capabilities of Polymer on Settleable Solids.

-------
indicates a very slight increase in oxygen demand of polymer sewage mix-
tures when compared with the raw sewage used in these tests which is in
the general range of 200 milligrams per liter.
                              TABLE VIII

          BIOCHEMICAL OXYGEN DEMAND (BOD) OF POLYMERS
Polymer
Concentration
Additive (mg/1)
AP-30
FR-4
D252
J-2FP
WSR-301
Polyox -
Coagulant- 7 01
500
500
500
500
500
500

DO at
Start
(mg/1)
7.70
7.80
8.20
8.20
7.60
5.90

DO at
5 days
(mg/1)
6.25
6.60
6.35
5.70
5.75
5.40

BOD at
5 days
(mg/1)
1.45
1.20
1.85
2.50
1.85
0.50

IZK
20/68
20/68
20/68
20/68
20/68
20/68

         Sludge Data Evaluation. The sludge data in Tables DC and X were
 treated by the method of least  squares and the results are plotted in Figures
 16, 17 and 18. Figure 16 shows that, at the beginning of the test period,
 the percent moisture is lower in sludge alone than it is in sludge and poly-
 mer mixtures; however,  as time progresses, the sludge-polymer mixtures
 have a much lower percent moisture value.   From this data it is reasonable
 to assume that the polymers  are beneficial in decreasing the water-retention
 capability of sludge; therefore, over a given time, yielding a dryer sludge
 cake for earlier disposal.

         In studying Figures 17  and 18 for total solids and volatile solids,
 it is apparent that the polymers increase the total solids and volatile solids
 per unit of volume over the test period.  Since the polymers help in moisture
 reduction, it is expected that with time,  values for total solids and volatile
 solids would increase in the sludge drying beds.
                                 41

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                             TABLE DC

           AFFECT OF POLYMERS ON SLUDGE DRYING BEDS
Polymer
or
Sample
Sludge Bed
Sludge Only
AP-30
AP-30
FR-4
FR-4
J-2FP
J-2FP
D-252
D-252
WSR-301
WSR-301
WSR-701
WSR-701
Polymer
Cone
(mg/1)
Percent Moisture
Days from Start
0
none 92. 61
none 93. 16
50 93.56
200 93.55
50
200
50
200
50
200
50
200
50
200
93.49
93. 76
93.52
93.49
93.02
93.81
93.59
96.67
93.54
92.74
1
90.22
90.58
91. 82
90.90
91.07
91.91
91. 16
91.64
90. 67
92.23
91.63
91.74
91.48
91.70
3
87.85
87. 68
87.26
87.45
84.26
87. 56
88. 68
87.94
88.50
88.46
87.06
88.77
88. 74
89. 09
7
81. 38
76. 10
79. 2.3
71. 03
80. 24
76. 98
80. 08
71.98
79.31
82. 39
81.40
81.38
74.20
81.49
14+
81. 32
77.21
76. 06
74. 38
71. 12
72.80
71. 42
71. 30
72.85
74. 06
76.59
75.67
71.42
75.45
28
72. 48
60. 65
64. 04
65. 44
65.42
58. 97
66. 24
32. 33
48. 48
30. 76
51.74
40. 78
30.20
61.69
NOTE:    "Sludge bed" is an average of two readings taken from a large
         sludge bed.

         "Sludge only" is an average of four readings taken from four
         tests beds.

         -tfRained during morning while samples were taken.
                                    42

-------
                                                  TABLE X

                               AFFECT OF POLYMER ON SLUDGE DRYING BEDS.
Polymer
or
Sample
Polymer
Cone .
(ma/1)
Total Solids (tng/1)
Days from Start
0
1
3 7
14*
28
Volatile Solids (mg/l)
Days from Start
0
1
3 7
14*
28
Sludge Bed   none 73,890 97,802  121,575 186,240  186,891  275,237 40,985  53,925  66,336  98,694  100,384  143,912
Sludge Only  none 68,357 94,219  123,192 239,024  254,421  393,423 37,395  49,293  67,765 128,549  135,700  170,918

AP-30         50 64,407 81,821  127,404 207,683  239,393  359,600 36,126  45,959  72,462 115,539  130,987  177,827
AP-30        200 64,550 90,963  125,468 289,653  256,245  345,625 36,288  50,360  68,652 160,272  145,744  191,269

FR-4          50 65,085 89,310  157,413 197,563  288,833  345,847 36,231  48,639  86,860 110,042  141,125  183,692
FR-4         200 62,366 80,888  124,419 230,243  272,033  410,309 36,132  45,324  71,406 131,037  155,260  223,349

J-2FP         50 64,775 88,376  112,981 199,154  285,808  337,634 36,904  43,787  63,218 112,685  157,824  182,389
J-2FP        200 65,088 83,558  120,636 280,235  287,042  676,737 36,101  46,451  63,768 155,429  158,027  366,549

D-252         50 69,769 93,298  115,005 206,862  271,467  515,176 39,178  51,715  65,131 118,007  145,766  287,044
D-252        200 61,948 77,681  115,441 176,125  259,409  692,403 35,466  44,649  66,222  98,898  140,732  386,643

WSR-301      50 64,150 83,750  129,367 185,955  234,145  482,570 35,548  46,338  72,160 100,134  130,648  253,583
WSR-301     200 33,328 82,545  112,316 186,219  243,339  592,230  7,166  47,344  64,754 107,985  150,182  327,966

WSR-701      50 64,567 85,204  112,641 258,005  285,809  697,951 35,517  47,081  62,213 137,807  157,722  379,466
WSR-701     200 72,586 83,001  109,123 185,052  245,490  383,103 41,730  46,802  61,816 105,686  133,404  201,867
NOTE:  "Sludge bed" is an average of two readings taken from a large sludge bed.

       "Sludge only" is an average of four readings taken from four test beds.

       *Rained during morning while samples were taken.

-------
       O - Combined Sludge Data
       D - Combined Polymer Data at 50 mg/1
       A - Combined Polymer Data at 200 mg/1
                  8    10   12   14   16   18  20   22  24   26
                        Time in Days
Figure  16.  Affects of Polymers (at Different Concentrations) on
           Moisture Content of Sludge.
                                 44

-------
 -
"-

 c


 X
 I
 -
 TJ
 -
  
 GO

 C
 -.

 CO
 T3
 -
 '
o
E-i
     550
      30

       Z
            O -  Combined Sludge Data


            D   Combined Polymer Data at 50 mg/1


            A -  Combined Polymer Data ZOO mg/1
J	L
 10   1Z   14  16   18   ;0
J	1	1	'     '    '
                                                     ZZ   Z4   26
                                                    J	1	l_
                            Time in Days


  Figure 17.  Affect of Polymers (at Different Concentrations) on Total
             Solids Content of Sludge.
                              45

-------
              Combined Sludge  Data

              Combined Polymer Data at 50 mg/1
              Comoiaed Polymer Data at 200 mg/1
                         Time in Days

Figure 18.  Affect of Polymers (at Different Concentrations) on
           Volatile Solids Content in Sludge.
                                 46

-------
                             SECTION IV

                FLOW-TEST EVALUATION OF POLYMERS
       Flow testing for additional evaluation of the six polymers previously
selected was conducted in a six-inch diameter test sewer designed initially
to provide a means of testing the polymers,  both as surcharged closed-
conduit flow and open-channel flow.

       In addition, the same facility was used with a four-inch diameter
line for the establishment of injection locations in a line to optimize
the operation with respect to the hydraulic cause of the surcharging of a
line.

Description of Flow-Test Facilities

       Six-Inch Diameter Sewer.  A 100-foot-long section of six-inch
asbestos-cement and transparent plastic sewer pipe was constructed to
evaluate the effects of different energy-re due ing polymers on sewage under
different flow conditions. The facility (see Figure  19 for  a schematic
drawing) was constructed so that the following parameters could be varied
to provide the variations in flow characteristics needed in the program.
                             TABLE XI

                      TEST FLOW PARAMETERS

       	Parameter	     Range

        Temperature,  F                       38 ~ 90
        Slope,  percent                       0.3-2
        Flow Rate,  gpm                       0 -  750
        Polymer concentration, mg/1            -  1.500
        Sewage concentration, ml/1           As required


        The temperature of the water or sewage used in  the test program
 was controlled by a combination heating and cooling recirculation system.
 The heating  system was a 800,000 btu  per hour output boiler designed to
 heat 22, 500 gallons of sewage from 65F to 90UF, in 8 hours.   The refrig-
 eration system consisted of four 15-ton cooling units and one 25-ton
 cooling unit operated in series with a total system output of 85 tons
 (1,020,000 btu/hr.) which was sufficient to cool 22,500 gallons of sewage
 from 70F to 38F in 12 hours.  The lowest testing temperature  was
 established as the  temperature at which icing would not occur in the
 evaporators, and thereby prevent possible damage  to the units and a  delay
 in the test program.

        The slope of the test pipe could be adjusted to  obtain a maximum
 of a two-percent flow-line slope.  To accomplish this, the entrance of the


                                47

-------
sewer line was fixed and the line was mounted on an I-beam which was
supported every 20 feet by a vertically adjustable base.  The span and
shape properties of the I-beam were such that the flow line of the pipe
would not deflect more than 0. 08 inch under the maximum live and dead
load anticipated. The slope of the line during testing was established
by using an engineer's level.

       The  sewage flow was accomplished by the use of a Marlow, Model
4C7 centrifugal pump driven by a gasoline engine which was fitted with a
gate valve for flow rate control. Flow  rates  up to 750 gallons per minute
could be achieved by varying the engine revolutions per minute and/or
the gate valve opening.

       The  polymer concentration in the sewage was achieved by pumping
a concentrated polymer slurry from a 1,000-gallon storage tank into the
sewage with a variable volume,  positive displacement pump capable of
pumping at rates from zero to  175 gallons per minute.  The flow rate of
the concentrated polymer  solution was determined from a calibration curve
of pump output versus the pump  vernier scale reading.  The injection of
the polymer occurred ahead of the test sewer section at variable rates
capable of providing concentrations of 0 to 1, 500 milligrams per liter in
the sewage.

        Sewage concentration was measured as a function of settleable
solids in terms of milliliters per liter.   To facilitate the addition of
concentrated sludge  (obtained from a local treatment plant)  to water in
the 22, 500-gallon reservoir, a diaphragm pump was used to transfer the
sludge from the transport  truck.   During this manufacturing process, the
4-inch gasoline driven centrifugal  pump was used to provide homogeneity
by using a recirculation loop.  Sampling ports were provided to various
locations along the sewage reservoir to facilite sample  withdrawal for
chemical analysis.

       A 30-foot section  of the 100-foot conduit was chosen for measure-
ment.  This measurement  section was located 100 pipe diameters (50 feet)
downstream of the line entrance.  The 100-pipe-diameter approach length
was provided to insure that all entrance affects had been suppressed and
that full turbulent flow had  been established. The  length of the test
section was determined to allow the flow to be analyzed over three pipe
sections. This minimized the affect of the pipe joints and gave pressure
drops of sufficient size to be read easily.  Two sections upstream from the
test zone, a transparent section was installed for visual observation of
the additive mixing with the sewage.

       The  six-inch test facility was instrumented to provide the data
and ranges indicated in Table XII.
                                     48

-------
 PAGE NOT
AVAILABLE
DIGITALLY

-------
                               TABLE XII

                   TEST PARAMETERS AND RANGES
                         Data	              Range
        Temperature, F                              0 - 200
        Flow Rate, gpm                              0 - 1,000
        Static Pressure at Sewer Line Entrance,
               inches H2O                            0-60
        Static Pressure at Start of 30-Foot Test
               Section, inches H2O                   0-205
        Static Pressure Drop Across 30-Foot Test
               Section, inches H2O                   0-20


        Three temperature indicators were used.  One indicator was placed
in the storage tank, one placed just prior to the 30-foot test section and
one placed just after the 30-foot test section.  The  sensors used were
Weston bimetal thermometers with an accuracy of +_  1/2 percent of the
reading with the bulb directly immersed in the sewage flow.

        A flowmeter was designed in the feed line following the primary
pump.  The  flowmeter consisted of a six-inch Foxboro meter and transmitter
(Type 1806-KAOS-RA) in conjunction with a Dynalog Electronic Recorder
(Model  No.  9650C) providing an overall flow measuring accuracy of 4^ 1
percent. As a system check, the effluent  of the  six-inch line emptied into
a catch basin which contained a standard 90-degree V-notched weir.

        The  static pressure-head at the sewer line entrance was read through
the use of a vertical sight glass marked every 0.0625 inches.

        A pressure transducer was installed at the start of the 30-foot sec-
tion (50 feet from sewer line entrance) to measure the static pressure at
this point.   The pressure  monitoring system consisted of a Foxboro Model
613 DM differential pressure transmitter in conjunction with a Sargent Model
SR recorder.  This system provided readings +_  1  percent of full-scale trans-
ducer capability.  The low side of the transducer was vented to atmospheric
conditions.

        Another pressure monitoring system similar to the above system was
provided to  measure the static pressure drop across  the 30-foot test section.

        Four-Inch Injection Point Effect Test Facility. A four-inch flow
system  was  built from the six-inch facility reservoir, pump,  flowmeter and
the instrumentation.  It was used to determine the most desirable distance
upstream from a  flow  constriction at which polymers should be injected.
                               51

-------
       Two four-inch lines were manifolded from the flowmeter and provid-
ed with manual gate valves to regulate the flow in each line (Figure ZO).
One of the lines was fitted with a Hersey rotating disc flowmeter so that
the flow in each line could be determined by a mass flow balance. The
other line contained four injection points  placed at distances of 7,  12,  17
and 22 feet upstream from the constriction formed by the junction of two
4-inch lines  discharging into one 4-inch conduit  and certain fittings.  The
same polymer injection technique was used as in the six-inch system.  The
system was designed to accommodate all  the restrictions tested, including
the circular cross-section long-radius ell, short-radius ell, tee and the
wye, and the square cross-section wye.  For testing the ells, provisions
were made for cutting off the non-injection leg of the system.  A transparent
section was  installed downstream of the seven-foot injection port so that
visual inspection of polymer/sewage  could be made.  Pressure taps were
installed five feet upstream and five feet downstream of the restriction so
both static pressures and differential static pressures  across the constric-
tion could be monitored.
 Flow Test Procedure

        Sewage Preparation.  The sewage produced by mixing water and sludge
 was developed to the required concentration by diluting raw sludge with wa-
 ter in the 22, 500-gallon reservoir.  The sewage reservoir was filled with
 water to within about 95-percent capacity and the raw sludge was then add-
 ed to the water which was kept under constant agitation to insure reason-
 able homogeneity of the sewage in the storage reservoir.  Samples were
 taken from the reservoir periodically until the desired sewage concentration,
 based on milliliter per liter of settleable solids, was achieved.

        Polymer Preparation.  To facilitate handling of the polymers during
 testing, a slurry was first prepared in the laboratory and then used to make
 concentrated water/polymer solutions of 5,000  milligrams  per liter in the
 1,000-gallon additive storage tank.  These solutions were  agitated gently
 for approximately four hours,  then samples were taken to the laboratory for
 viscosity tests to insure that complete hydration had occurred. An inert
 tracer dye was added to the solution so the additive  could be  observed dur-
 ing the testing procedure to determine the degree of mixing of additive with
 sewage.  A detailed discussion of the technique used in mixing the polymer
 slurry is given in Appendix D.

        Thermal Conditioning.  Once the desired sewage concentration had
 been achieved, the sewage was adjusted to the proper temperature for test-
 ing.  The cold runs at 38F were achieved after an overnight chill of the
 sewage occurred by circulating the water/sewage mixture through the chiller
 unit  of the refrigeration equipment.  The second set  of data was made at the
 ambient water  temperature (approximately 70F).  Following this test, the
 high temperature test at 90F was performed by heating the sewage in the
 same manner as the temperature reduction process with the exception that
 the sewage was circulated through the boiler.  This  sequence of testing
 (chill-down, ambient,  heat-up) proved to be the most desirable  since it
                                      52

-------
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Four- Inch Flow System Schematic Diagram

-------
allowed for maximum utilization of test time (that is, it allowed night chill-
down and daytime heat-up which minimized the energy  requirements for the
environmental testing).

       Typical Flow Testing Procedure.  Throughout the flow test program,
all instrumentation was  periodically checked for calibration.  The pressure
transducers were checked with  a standard water manometer, the magnetic
flowmeterwas checked with a positive displacement flowmeter placed in
series on the line; the additive pump was checked in the same manner as
the magnetic flowmeter; and the thermal sensors were checked in a constant
temperature bath.  Also, the slope of the sewer flow line was determined
before each run.  The initial polymer concentration was arbitrarily selected
but subsequent concentrations were based on the calculations performed
during the testing.  The polymers and concentrations tested are shown in
Table XIII below.
                              TABLE XIII

              FLOW TEST POLYMER CONCENTRATIONS

          Polymer	Polymer Concentration (mg/1)

        AP-30                            100,  Z50 and 500
        FR-4                             100,  250 and 500
        D-252                           100,  250 and 500
        J-2FP                            500 and 1,000
        WSR-301                         50, 100 and 200
        Polyox Coagulant-701             50, 100 and 200


       The six-inch sewer system's performance was  determined with a
slope of 0.003 for three different head conditions for each polymer at each
concentration.  The resulting sewage  flow rates  tested were 350,  450 and
550 gallons per minute.  Additional testing was done at grades of 0. 3 and
1.0 percent.

       The volume of the 22, 500-gallon reservoir was sufficient to provide
flow for twelve different data collection operations.  Each set of data was
taken at a constant sewage concentration and sewage temperature. Three
sewage flow rates and three polymer concentrations at each flow rate were
tested.

       Once the polymer solution and sewage were ready to be tested,  flow
of sewage was started by the Marlow pump and the instrumentation was
zeroed. The system flow rate was then brought up to the desired value and
the  vernier on the polymer injection pump was  set at the proper value but
not  actuated.   The sewage flow system was then allowed to reach a steady-
state condition, sewage samples were taken for analysis and the following
data recorded:
                                     54

-------
               Date
               Ambient temperature.
               Sewage reservoir temperature.
               Sewage temperature at the entrance of the test section.
               Sewage temperature at the exit of the test section.
               Sewage flow rate.
               Static pressure at sewer line entrance.
               Static pressure at the entrance of the test section.
               Static pressure drop across test section.
               Weir box reading.

        The polymer injection pump was then started at the first concen-
tration setting, and the test  section flow again was allowed to reach
steady state conditions.  Again, the required data was recorded and the
procedure repeated (for the different polymer concentrations and sewage
flow rates) until the data matrix of 12 sets was completed.

        Flow Restriction Test Procedure.  Of the six polymers  tested in the
six-inch test facility, four were selected for evaluation in the four-inch
test facility, to establish the most effective injection point distance up-
stream for typical flow restriction characteristics.  The four polymers and
the concentrations tested are given in Table XIV.

                               TABLE XIV

       	RESTRICTION TEST POLYMERS   	

       	Polymer	Polymer Concentration (mg/1)

       AP-30                              250 and 500
        FR-4                               250 and 500
       WSR-301                           100 and 200
        Polyox Coagulant-701              100 and 200
       During these restriction tests, water was used rather then sewage
because the data indicated minimum differences between water and sewage.
Preparation of the concentrated polymer solutions was identical to that
previously described.

       All instrumentation was zeroed prior to each test run to prevent
recording  errors and to insure that all instrumentation was functioning.
The test procedure for the four-inch system depended on the system con-
figuration being tested, and whether the flow constriction resulted  from
deformational losses  or was caused by the junction of two flows, as in
the tee and wye sections.

       The procedure used for the long- and short-radius elbows was as
follows.   The Marlow primary pump was started and the flow rate adjusted
to the flow rate to be used and,  after steady-state flow conditions were
obtained,  the following data recorded:
                              55

-------
               Water temperature in the line.
               Water flow rate.
               Static pressure at entrance to the blockage area.
               Static pressure drop across the blockage area.
               Date.
               Ambient temperature.

       The polymer pump vernier was set to the proper injection rate and
the pump started.  Injection was made at the nearest injection point (No.
1) first and the system allowed to reach steady-state prior to data record-
ing.  This first injection point was  then closed, and the second injection
point was opened, and the procedure was repeated for each  of the other
two injection points.

       The procedure used for the tee and the two wyes was as follows.
The Marlow primary pump was again started with the valves  in the two
upstream lines  in the full open position.  Once the flow system reached
steady-state, the following data was recorded:

               Water temperature in the line.
               System total flow rate.
               Water flow rate in the non-injection line.
               Static pressure at entrance to turned flow portion
                 of the blockage area.
               Static pressure drop across the straight flow
                 portion of the blockage area.
               Static pressure drop across the turned flow
                 portion of the blockage area.
               Ambient temperature.

       The same injection procedure and  data acquisition was then follow-
ed as described for the elbows.  The injection system was then taken off
line and the flow was redistributed  through the two legs of the primary
flow system in  the lines.  The above procedure was repeated until eight
different flow distributions had been achieved.

Chemical and Physical Characteristics of Polymer-Sewage System

       During the tests in which selected polymers were  injected into
the six-inch test conduit, statistical sampling was conducted on the
sewage and polymer-sewage combinations (forWSR-301 and Polyox Coag-
ulant-701) to determine any affects  of the polymers on sewage, and to
record the specific characteristics of the material used in the flow data
collection.

       By its very nature, raw sewage cannot be considered homogeneous;
however, in the project tests, parameter values were controlled as well
as possible so  that comparative values could be established within the
data.   The test parameters were established from various  sewage treat-
ment plant records in the Dallas, Texas, area (Table XV).
                                    56

-------
                          TABLE XV

                RAW SEWAGE CHARACTERISTICS
                    OF DALLAS,  TEXAS AREA
Total solids, mg/1
Dissolved solids, mg/1
Suspended solids, mg/1
Total volatile solids, mg/1
Total non-volatile solids, mg/1
PH
Chlorides, mg/1
DO, mg/1
BOD, mg/1
Sulfates, mg/1
Total sulfides, mg/1
H2S, mg/1
Ammonia nitrogen, mg/1
Temperature, F
1,370
1,010
360
780
591
6.5
333
1.0
212
161
2.7
1. 2
0. 4
75
       Tests conducted on sewage or polymer and sewage were conducted
in accordance with procedures outlined in Standard Methods for Examina-
tion of Water and Wastewater  with measured parameters, including set-
tleable solids,  total solids, dissolved solids, suspended solids, pH,
chlorides, hardness, chemical oxygen demand (COD), dissolved oxygen,
specific conductance,  oil and grease, and temperature.

       The control factor accurately maintained in diluting raw,  concen-
trated sewage,  to the levels generally found in combined municipal sew-
age, was settleable solids. Recorded data of these tests as they relate
to the flow testing with various polymers and polymer concentrations  are
found in Table XVI.

       The values of chlorides and calcium-carbonate hardness follow
a narrow consistent range of values (Table XVI) as expected, since these
parameters are  primarily derived from the water in the sewage.  These
factors do not contribute  to or deter  the function of the polymers as
friction reducers in overflowing sewer lines.

       Values obtained from the tests, which depend upon the electrolytic
nature of the sewage and the polymers (i. e. , pH and specific conduc-
tance), vary erratically with increased polymer concentration;  however,
the maximum variation in pH was 0. 69 and the maximum variation in
specific conductance was 32.4 micro-mhos per cubic centimeter.

       The tendency for the values of the total solids and dissolved
solids to increase with an increase in polymer concentration was expected
because of the  gross quantity  of polymer injected.
                              57

-------
       The  suspended solid values of the sewage were reduced when
polymers were injected into the model sewer line, with the greatest
reduction obtained with the lower polymer concentration (50 milligrams
per liter).  The suspended  solids are  dependent upon the total solids and
the dissolved solids; therefore,  as the polymer solids concentration
increased, the reduction in suspended solids generally decreased
proportionately.

       Erratic values were found during the oil and grease testing and
probably occurred because  the material tended to coalesce or lump.  The
data showed no change with change in polymer concentration.

       The  COD values increased with increases in the polymer concen-
tration.  The test indicated the amount of carbonaceous or organic mater-
ial available for oxidation  by a strong chemical oxidant.   Thus the  analysis
should show increased COD due to inclusion of the polymers (an  organic
material) which are, although, a minor part of the immediate biochemical
load upon the oxygen assets of the sewage receiving the polymer injection.

       An increase in COD was,  in fact,  measured in the polymer-sewage
mixture as the polymer concentration  was increased.  This increase in
COD can be seen by the tabulations shown in Table XVI.

       In a typical sewer system, the polymer concentration injected
should be greatly diluted when the flow from a surcharged section of the
collection system merges with the downstream flow from other sections
of the collection  system.   For example, in one sewer system investigated
during rainy weather, the flow in the  restricted section was 9.4   million
gallons per  day (mgd).  Since the total downstream flow in the system
was estimated at 40 mgd, the polymer concentration used should  be
diluted by a factor of four;  however,  if the polymer injected in a  collec-
tion system to reduce the energy required to overcome friction losses
should result in any concentration at  the treatment plant, it should be less
than those normally  used for coagulation.  Thus,  the organic load of the
effluent of the treatment  plant should not be materially, if at all, affected
by the polymers injected into the collection system.

       The  dissolved oxygen (DO) values showed definite relationship
to the amount of agitation occurring in the storage reservoir during
testing, and to the temperature of the sewage; however,  no correlation
pattern developed between  the DO parameter and  the polymer injection
concentration.  There was  some  tendency for DO  values to be slightly
higher at low temperatures  than at higher temperatures, due to the better
oxygen-retention  capability of water at lower temperatures.

       Most of the  test data obtained from measuring the various charac-
teristics  showed that there was little  affect of the polymers injected
upon the  sewage and, for practical purposes, all polymers injected at
various concentrations remained available for friction reduction.
                                     58

-------
 PAGE NOT
AVAILABLE
DIGITALLY

-------
Six-Inch Flow System Test Results
       The results of the six-inch test sewer screening were obtained by
evaluating (under the controlled conditions described in Table XVII) five
of the six selected polymers.  One polymer candidate, J-2FP, was not
tested in the matrix because of its ineffectiveness as a friction reducer.
The test results presented were  established as a function of the non-
polymered sewage flow rate, sewage characteristic,  pressure loss,
temperature,  and polymer concentration.

        The matrix of test data taken on the six-inch test facility is shown
in Table XVII.  Several data points were run repeatedly to insure repeat-
ability of the data.
                           TABLE XVII

                  MATRIX OF FLOW DATA USED
               Polymer Concentration
  Polymer	     (mg/1)	
                         Temperature
            Sewage
           Settleable
          Solids (ml/1)
 AP-30
 FR-4
 D252
 WSR- 301
  Poly ox
  Coagulant-
  701
100,  250 and 500
100,  250, 350 and 500
100,  250, and 500

100,  250, and 500
100,  250, and 500
100,  250, and 500
100,
100,
100,
50,
50,
50,
50,
50,
50,
50,
50,
50,
50,
50,
50,
50,
50,
50,
50,
50,
50,
250,
250,
250,
100,
100,
100,
100,
100,
100,
100,
100,
100,
100,
100,
100,
100,
100,
100,
100,
100,
100,
and 500
and 500
and 500
and 200
and 200
and 200
and 200
and 200
and 200
and 200
and 200
and 200
and 200
and 200
and 200
and 200
and 200
and 200
and 200
and 200
and 200
38
70
90

38
71
90

38
70
90

38
70
90
38
74
90
38
74
90

38
73
90
38
74
90
38
74
90
0
0
0

0
0
0

0
0
0

0
0
0
 3
 3
 3
 9
 9
 9

 0
 0
 0
 3
 3
 3
 9
 9
 9
                                61

-------
       The results of the six-inch sewer section screening tests are pre-
sented graphically in Figures 21 through 53. Examples and an explanation
of how the graphs were derived from actual test data are given in Appendix
C.

       Initially the behavior of the polymers in the six-inch  system was
observed in water containing no sewage.  These tests were performed at
various flow rates, polymer concentrations, and temperatures.  For the
purpose of comparison, a flow rate of 300 gallons per minute was chosen
to evaluate the increase in flow rate at constant head pressure.   The calcu-
lations of increased  flow rate with polymer, as shown in Figures  21 through
53,  was accomplished by using  flow curves (flow rate versus friction pres-
sure loss) to determine the friction head loss for sewage at 300 gallons per
minute. At this head loss, flow rates for sewage with each of three polymer
concentrations  (50 ppm, 100  ppm,  and 200 ppm)  were determined, and the
percent flow increase calculated as

               Flow  with polymer - 300  gpm
                          300  gpm

       The polymers selected for testing, did not produce high friction
pressure losses as occurred for  sewage without  polymer.  Therefore, it  was
necessary to extrapolate the flow rate that would have occurred for the sew-
age/polymer mixture. Specific concentrations were then chosen for each
polymer based  on its cost and the  amount of additive required.  Based on
the selected polymer concentrations,  the  results of this analysis indicated
that, over a temperature range of 38F to 90F, the polymers ranked in the
following  order with respect to flow increase at  constant head 1) Poly ox
Coagulant-701, 2)WSR-301, 3) AP-30,  4) D-252, 5) FR-4, and  6) J-2FP.
Concentrations, temperatures and  derived flow increases  are shown in
Figure 21.

        Because of the relatively high concentrations required to achieve
flow increases comparable with the other  polymers,  J-2FP was not scheduled
for  further testing after the ambient temperature  run.  This polymer additive
was the least  expensive  of the six additives tested, but its lower cost was
not sufficient to overcome the disadvantages of  having to use larger injec-
tion equipment and larger quantities  of the polymer.

       Although D-252 ranked fourth in the rating,  it was not chosen for
further consideration due to the  difficulty of on-site injection, as explained
in Section III.   The process involved would require batch  mixing and thus,
would require more complicated  and costly injection equipment.   Since this
was the only major disadvantage associated with the additive, a complete
test data matrix was performed.  It is believed that, under certain circum-
stances, D-252 could prove to be  a contender.  One such case might be
where the sewage or sludge is pumped over long distances in forced mains
resulting in high fluid shear rates  in the line.
                                     62

-------
  140
  120
   100
$ 80
 I
UJ
a
UJ
IT
   60
o
    40
tr
UJ
Q
    20
?-WSR 301 @  200  PPM
  -POLYOx  COAGULANT  701 (3>  100 PPM
o -AP- 30 @ 250 PPM 	
o -D252 (cb 250 PPM
n-FR-4 @ 250 PPM
X -J-2FP@ 500  PPM
                         TEMPERATURE  F
  See example of graph derivation in Appendix.
     Figure 21.  Comparison of the Effectiveness of Six Additives
               in Water as a Function of Temperature.
                             63

-------
   140
   120
   100
*
 k

 1
 c  80
 ;
 CO
 LU
   60
o
Q  40
UJ

E
   20
                      o-o ml/I SETTLEABLE  SOLIDS  SEWAGE
                      D-3mi/i SETTLEABLE  SOLIDS  SEWAGE
                               SETTLEABLE  SOLIDS  SEWAGE
      35   4O
                    50
60
70
80
90
                        TEMPERATURE   F
    *
    See example of graph derivation in Appendix.
       Figure 22.  Comparison of the Effectiveness of WSR-301 at
                 200 mg/1 in Sewage as a Fraction of Temperature.
                                .. 64

-------
   140
   120
   100
o
E
LL)
Q
    80
Ld
o  60
Q 40
   20
 o-O ml/1 SETTLE ABLE SOLIDS  SEWAGE
 a-3ml/l SETTLE ABLE  SOLIDS  SEWAGE
 -9 ml/I SETTLEABLE  SOLIDS  SEWAGE
      35  40
50        60
    TEMPERATURE
70
80
90
     See example of graph derivation in Appendix.
  Figure 23.  Comparison of the Effectiveness of Poly ox Coagulant-701 at
            100 mg/1 In Sewage as a Function of Temperature.
                             65

-------
S
o
UJ
>
IT
UJ
O
    140
    120
    100
    80

co

Lu
K
o

    60


o
     40
     20
                                          o 38  F

                                          a 73F

                                          a 90F
                  2          4          6         8

                SEWAGE   SETTLEABLE  SOLIDS   mi/i
 See example of graph derivation in Appendix.

     Figure 24. WSR-301 at 200 mg/1 in Sewage at Indicated
               Temperatures, Six-Inch Test Facility.
                                                             10
                                66

-------
     140
     120
*

 k.
     100
     80
UJ
CO

LJ
cr
0
z
     60

o

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Q
UJ
>
cr
UJ
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     40
     20
                                          o  38 F

                                          a  73 F

                                          A  90 F
                             468
                SEWAGE   SETTLEABLE  SOLIDS  (mi/D
See example of graph derivation in Appendix.

          Figure 25.  Polyox Coagulant-701 at 100 mg/1
                    in Sewage at Indicated Temperatures.

                          67
                                                             iO

-------
    140
k.

o
Q:
ui
en
<
LU
<2L
U
0
Q
UJ
>
tr
UJ
    120
    100
                                                 (300) gpm
(250)gpm
                 100       200       300      400
                 POLYMER CONCENTRATION-PPM
n
 See example of graph derivation in Appendix.

       Figure 26. AP-30 in Six-Inch Test Facility at 38F.
        500
                               68

-------
4>
o
CREASE -PERCENT
DERIVED
o

                                                 .. (250) gpm
                 100        200       300       400
                POLYMER  CONCENTRATION - PPM
See example of graph derivation in Appendix.

      Figure  27. AP-30 in Six-Inch Test Facility at 70F.
500
                         69

-------
k
1
I
UJ
en
<
LLJ
CC
CJ
o
_l
LL

0
UJ

E
UJ
O
                  100       200       300       400

                 POLYMER  CONCENTRATION PPM
 See example of graph derivation in Appendix.

       Figure 28.  AP-30 in Six-Inch Test Facility at 90F.
500
                               70

-------
k

I

I
UJ
a
UJ
cr
o
o
Q
UJ
>

cr
LU
o
     140
     120
 100
 80
     60
                                            --(300)gpm
bee
  u          100       200       300       400
             POLYMER  CONCENTRATION  PPM

example of graph derivation in Appendix.
                                                         500
       Figure 29. FR-4 in Six-Inch Test Facility at 38F.

-------
fc
 I
LL)
o:
u
o
111
>
cr
UJ
    140
    120
    100
80
                                            -(400) gpm
                                                  (350) gpm
                                                 -(300) gpm
                           200
                                 300
400
                                                         
                                                          500
 See
             POLYMER  CONCENTRATION-  PPM

example of graph derivation in Appendix.


   Figure 30. FR-4 in Six-Inch Test Facility at 71F.
                               72

-------
k
UJ
GO
<
UJ
tr
o
o
0
UJ

E
UJ
o
     140
     120
     100
     80
     60
40
     20
                                             {400) gpm

                                             (350) gpm
                                            -(300) gpm
 See
  O          100       200       300      400
             POLYMER  CONCENTRATION-  PPM
example of graph derivation in Appendix.

   Figure 31. FR-4 in Six-Inch Test Facility at 90F.
                                                          500
                          73

-------
k
UJ
CO
Q
UJ
E
    140
    120
100
     80
     60
 40
     20
7
                 100
                                             (400) gpm
                                                  (350)gpm
                                             ,(300) gpm
                      200
                   300
400
500
                 POLYMER  CONCENTRATION -PPM
 See example of graph derivation in Appendix.
        Figure 32. D-252 in Six-Inch Test Facility at 38F.
                              74

-------
I4O
Tw
I2O
*
k. 100
tk

. 80
UJ
en
UJ

///
F
II













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-(350) gpm




-(300) gpm









                50        IOO       150       200
                POLYMER  CONCENTRATION-PPM
*See example of graph derivation in Appendix.

       Figure 33.  D-252 in Six-Inch Test Facility at 70F.
250
                          75

-------
140
120
*
^ 100
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^(350) gpm

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                100       200       30O      400

                 POLYMER  CONCENTRATION- PPM
*
 See example of graph derivation in Appendix.


       Figure 34. D-252 in Six-Inch Test Facility at 90F.
500
                              I 0

-------
    140
    120
    100
     80
UJ
CO

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cr
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     60


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     40
     20
(400)
_-	

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(300)gpm
                 200^      400       600       800

                  POLYMER CONCENTRATION-PPM

      See example of greph derivation in Appendix.


      Figure 35. J-2FP in Six-Inch Test Facility at 72F
     1000
                            77

-------
5
fc
 i
 UJ

cr
UJ
Q
    140
    120
    100
    80
UJ
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u

     60
o
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     40
     20
                                                  (300) gpm
                 50        100       150       200
                 POLYMER CONCENTRATION-PPM

 See example of graph derivation in Appendix.

  Figure 36.  WSR-301 in Six-Inch Test Facility at 38F in Water.
                                                          250
                               78

-------
2
Q
UJ


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UJ
    140
    120
    100
    80
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    60
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40
    20
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                                                  (300)gpm
(250)gpm
                 50        100       150       200

                 POLYMER CONCENTRATION-PPM
 See example of graph derivation in Appendix.


  Figure 37.  WSR-301 in Six-Inch Test Facility at 70F in Water.
                                                    250
                         79

-------
    140
 i

UJ
UJ
cr
o
o
Q
UJ

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    120
    100
                 50        100       150       200

                 POLYMER CONCENTRATION-PPM
See example of graph derivation in Appendix.


  Figure 38. WSR-301 in Six-Inch Test Facility at 90F in Water.
250
                               80

-------
K.

I
Q
LU

E
    140
    120
    100
    80
UJ
00

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    60
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     20
                 V7
                  /
                                               ,(300)gpm
                                          -(250) gpm
                 50       100       150       200

                 POLYMER CONCENTRATION-PPM
 See example of graph derivation in Appendix.


         Figure 39.  WSR-301 in Six-Inch Test Facility
                   at 38F in Sewage (3ml/l Settleable Solids).
                                                  250
                        81

-------
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0

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g
    100
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     40
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                               X
                                                 X300) gpm




                                                 -(250) gpm
                   0

                  POLYMER
                            100       150       200

                            CONCENTRATION -PPM
250
 See example of graph derivation in Appendix.


       Figure 40. WSR-301 in Six-Inch Test Facility at 70F

                in Sewage (3 ml/1 Settleable Solids).
                               82

-------
Q
LU
    140
    120
    100
     80
I


I
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LU
en
<
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                                                   (300) gpm
                                                (250) gpm
                  50        100       150       200

#                 POLYMER  CONCENTRATION-PPM

 See example of graph derivation in Appendix.


      Figure 41. WSR-301 in Six-Inch Test Facility at 90F

                in Sewage (3 ml/1 Settleable Solids).
                                                          250
                         83

-------
    140
    120
I
 I
UJ
CO
<
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o:
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                   50        100        150
                   POLYMER  CONCENTRATION
 *See example of graph derivation in Appendix.
  200

PPM
250
       Figure 42.  WSR-301 in Six-Inch Test Facility at 38 F
                 in Sewage (9 ml/1 Settleable Solids).
                                84

-------
NCREASE - PERCENT
o
cr
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8
                                      /
                                                  --{300) gpm



                                                   (250) gpm
                 ^0         100        150

                  POLYMER  CONCENTRATION-PPM

*See example of graph derivation in Appendix.


       Figure 43.  WSR-301 in Six-Inch Test Facility at 70F
                 in Sewage (9 ml/1 Settleable Solids).
250
                          85

-------
    140
    120
k

I
    100
     80



UJ
K
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     60


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40
     20
                                                   -(300) gpm
                                                  -~(250)gpm
                  50

                  POLYMER
                        100        150
                        CONCENTRATION
  200
PPM
                                                            250
 See example of graph derivation in Appendix.
       Figure 44.  WSR-301 in Six-Inch Test Facility at 90 F
                 in Sewage (9 ml/1 Settleable Solids).
                                86

-------
    140
I
Lu
CO
u
2


O
_l
U.

Q

>

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    120
    100
                                                  (300) gpm
                                                  (250) qpm
                 50        100        150       200
                 POLYMER CONCENTRATION-PPM
See example of graph derivation in Appendix.

      Figure 45.  Polyox Coagulant-701 in Six-Inch Test Facility
                at 38F in Water.
                                                          250
                         87

-------
    140
 I

UJ
UJ
tr
u
O

LL.


O
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x
                                                  (300) gpm

                                                  (250) gpm
                  50

                  POLYMER
100       150        200
CONCENTRATION - PPM
250
 See example of graph derivation in Appendix.
          Figure 46.  Polyox Coagulant- 701  in Six-Inch

                    Test Facility at 73F in Water.

-------
2
u
LLJ
>
cc
UJ
a
    140
    120
    100
     80
UJ
LD

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ET
U

     60


o
    40
     20
                                                 ^300) gpm

                                                  (250) gpm
                 50        100       150       200

                 POLYMER CONCENTRATION-PPM
See example of graph derivation in Appendix.

         Figure 47.  Polyox Coagulant-701 in Six-Inch
                   Test Facility at 90F in Water.
                                                          250
                         89

-------
   140
    120
K.

    100
     80
UJ
CO

UJ

cc
UJ
Q
    40
     20

                                    	(250) gpm
                                                  (300)gpm
                 50        100       150       200
                 POLYMER  CONCENTRATION-PPM

See example of graph derivation in Appendix.

         Figure 48.  Polyox Coagulant- 701 in Six-Inch
                   Test Facility at 38F in Sewage
                   (3 ml/1 Settleable Solids).

                              90
                                                           250

-------
    140
    120
k.


    100
     80
UJ
CO


UJ
T
O


     60
o
UJ
>
cc
UJ
o
40
     20
                                                  ,(300) gpm

                                                 M250)
             50        100        150       200
             POLYMER CONCENTRATION-PPM
                                                           250
 See example of graph derivation in Appendix.
    Figure 49.  Polyox Coagulant- 701 in Six-Inch Test Facility

              at 73F in Sewage (3ml/ 1 Settleable Solids).

-------
    140
S
o
 I

LU
UJ
cc
o
O
O
U
>

IT
UJ
Q
    120
    100
                 50         100        150       200

                 POLYMER  CONCENTRATION-PPM
it
 See example of graph derivation in Appendix.

    Figure 50.  Polyox Coagulant-70 1 in Six-Inch Test Facility
              at 90F in Sewage  (3 ml/1 Settleable Solids).
                                                           250

-------
    140

LU
CO
<
LJ
(T
O
O
 Q
 LU
 >
 cc
 LJJ
 Q
    120
    100
                   50
                   POLYMER
100        150        200
CONCENTRATION - PPM
                                                             250
 See example of graph derivation in Appendix.

    Figure 51.  Polyox Coagulant-701 in Six-Inch Test Facility
               at 38F  in Sewage (9 ml/1 Settleable Solids).
                           93

-------
   140
ro
o
o
o
oo
o
CREASE - PERCENT
OW I


o>
o
.&
o
DERI

                                                ,(300) gpm
                                                 (250) gpm
                 50        100       150       200

                 POLYMER  CONCENTRATION-PPM

See example of graph derivation in Appendix.


   Figure 52.  Polyox Coagulant-701 in Six-Inch Test Facility

             at 73F in sewage (9 ml/1 Settleable Solids).
250
                              94

-------
k.

s
Cj
i

UJ
Q
Ld
    140
    120
    100
     80
Id
a
o

     60


o
     40
     20
                       /
                     /
                    /
                                                  (300) gpm
                 50        100       150       200

w                POLYMER  CONCENTRATION-PPM

 See example of graph derivation in Appendix.


    Figure 53.  Polyox Coagulant-701 in Six-Inch Test Facility
              at 90F in Sewage  (9 ml/1 Settleable Solids).
                                                          250
                         95

-------
        The four polymers selected for further consideration as a result of
the initial tests performed in the six-inch facility were:  Polyox Coagulant -
701, WSR-301, AP-30 and FR-4.   Subsequent to this selection, a more
detailed performance evaluation and further testing was done  on these four
polymers to provide as much information as possible for incorporation in
the full-scale field tests.

        The flow increase of the system using FR-4 was not as great as
that achieved by the other three additives under any of the flow conditions
tested.  It can be seen in Figure 30 that the maximum flow increase,  approx-
imately 40 percent,  occurred at a  temperature of 70F.  The additive was
quite sensitive to the temperature of the base fluid as indicated by the
reduction in flow increase at temperatures of 38F and 90F.

        The optimum concentration of AP-30 was determined to be approxi-
mately 250 milligrams per liter when compared with  the base fluid.  This
additive varied about six percent in its flow-increasing ability over the
temperature range from 38  to 90F.  The average derived  flow increase
obtained by using AP-30 was about 113 percent (2. 13 times original flow).
The advantages  of this polymer were its  stability over the temperature range
tested and its relative inertness to the sewage.  The main disadvantages
were cost and the relatively high concentrations  required as compared with
the polyethylene oxide based additives tested.  Nevertheless, AP-30 poly-
mer could be induced into the sewer line with relatively inexpensive equip-
ment.

        The remaining two polymers tested in the six-inch test facility were
the polyethylene oxides, WSR-301 and Polyox Coagulant-701.  These two
polymers were tested in water and controlled sewage concentration of three
and nine milliliters per liter settleable solids.  The reactions  of WSR-301
and Polyox Coagulant-701 to both temperature and sewage concentration
made the analysis of the test results rather complex (Figures  21 through
25).  Both additives, however,  were extremely effective with  respect to
increasing the flow of sewer systems.

       The analysis of the test data for WSR-301 and Polyox  Coagulant-
701 showed similar flow  characteristics.  WSR-301  at 200 milligrams per
liter varied from a derived flow increase  of  125 percent (2. 25  times original
flow) at 38F to a maximum of 135  percent at 70 F then decreasing to 110
percent at 90F with 9 milliliter per liter settleable solid  sewage.  The test
data  appeared to indicate that three milliliters  per liter of settleable solids
had more effect on this additive than did nine milliliters per liter.  The
same phenomena with  sewage concentration occurred with Polyox Coagulant-
701;  however, 701's ability to  increase flow varied  more with temperature.
At 9 milliliters per liter settleable solids  concentration, the derived flow
increase for Polyox Coagulant-701 varied from 125 percent at  38F to 141
percent at 73F and then dropped to 117 percent at 90F.

       In general the results showed that polymer effectiveness, to increase
flow at a constant head or reduce the frictional losses, is dependent upon
sewage characteristic and the sewage temperature.
                                     96

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Polymer Injection Point Test Results

        Tests were  performed in the four-inch test facility to determine the
affect of the point of injection with respect to the location of specific pipe
fittings used in sewers.  These tests were performed with AP-30, FR-4
WSR-301 and Polyox Coagulant-701.   The restrictions tested were of two
general types,  such as the long- and short-radius elbows where flow
restrictions occur as a result of flow deformation, and wyes and tee where
flow restrictions occur due to both flow deformation and turbulence.

        To  facilitate the analysis,  the data was normalized before plotting,
which resulted in the definition of a  performance  index (. ) that was the
ratio  of the flow increase due to injection at point "i" (i =  1 to 4) to
the maximum flow increase experienced. Also, the distance from the
injection point to the restriction is expressed in equivalent pipe diameters,
L/D,  where L is the length of the pipe and D is the pipe diameter.

        Figure 54 represents the data for all the constrictions tested,
including results of the square  sewer line tests,  which agreed  with the
circular tests.   It should be observed that the additive injection point
affect was negligible for all the restrictions tested within the L/D range
used.  Even though the smallest L/D tested was 21,  it is felt that this
mixing was observed to take place at the restriction  itself.  It  is also
possible that all injection points were so close to the restriction that
none  of the results are valid.

        The injection point tests were performed to determine how far
upstream it was necessary to inject  a polymer in  order to relieve a line
surcharged by the junction of other lines which were not surcharged.
Test results showed that location of  the polymer injection point is not
critical, and that the polymer slurry  need be injected only slightly up-
stream of the surcharged point.

Affects of  Solid Concentrations on Polymers

        During  rainstorms, the heavy flow of fluid through combined sewers
can flush accumulated material off sewer walls resulting in settleable
solids as high  as 1, 551 milligrams per  liter.   Previous tests  indicated that
Polyox Coagulant-701 and WSR-301  were affected by solids in  sewage,
resulting in a reduction in the amount of derived flow increase  obtained.
It appeared that a portion of the polymers  used to increase flow was sac-
rificed to coagulate the sewage solids.  This same coagulating phenomena
may occur with sand,  silt,  and sludge during the flushing periods.

        Of the six polymers tested, three were significantly better friction
reducers,  Polyox Coagulant-701,  WSR-301, and AP-30.  Of the three best
polymers,  two  were affected by sewage, (e. g. ,  some deterioration in fric-
tion reduction performance was noticed  when tested in sewage  instead of
water).  Therefore,  these two polymers, Polyox Coagulant-701 and WSR-
301,  were tested additionally in sewage with high concentrations of solids
at ambient temperature.
                                97

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  I
  x
  UJ
  o
LU
O


<


cr:
  cc
  UJ
  Q.
      1.0
    0.8
      0.6
      0.4
      o.;
                       EXTRAPOLATED
                        REGION
        0          20         40        60        80        100

                 DISTANCE  UPSTREAM  OF  BLOCKAGE  (L/D)
Figure 54.  Injection Point Affect on Sewage System Flow Constrictions.

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       Shown in Figures 55 through 58 are the results of the additional
tests using high concentrations  of settleable solids and three concentrations
of each polymer, 50 milligrams per liter,  100  milligrams per liter, and 200
milligrams per liter.  The flow increase results were obtained by measuring
the flow and pressure drop characteristics and by using a test procedure
identical to early tests except that the sewage was neither heated nor cooled.

        In sewage with approximately 1, 500 milligrams per liter of settle-
able solids, Polyox Coagulant-701 at 100 milligrams per liter increased the
derived flow rate of the sewage  by 2.05 times the original flow rate for sew-
age without polymer (See Figure 57).

        In sewage with approximately 1, 600 milligrams per liter of settleable
solids, WSR-301 at 200  milligrams per liter increased the derived flow rate
of the  sewage by 2.4 times the  original flow rate for sewage without polymer
(See Figure 58).

        It is anticipated that the settleable solids used in this test had the
greatest adverse affect possible on the polymer performance,  except in the
instances of sludge movement.  The heavy solids concentrations in sewers
normally consist of large percentages of sand and  silt which do not tend to
attract the polymers for coagulation like sewage solids.  The high concen-
trations of solids are believed to occur for a relatively short period of time
when high sewage  flow scours the pipe clean of material that has accumu-
lated since the last heavy flow.

        Polymer selection for use in a sewer line should take into considera-
tion the solids concentration in the wastewater. Previous tests  showed that
one good  flow-increasing polymer, AP-30, was not affected by solids, where-
as Polyox Coagulant-701 was affected more than WSR-301.
                                 99

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CL
UJ

o
    140
    120
    100
     80
g
O


I

 I

UJ
en
<
UJ
en
o
     60


o
     40
     20
                                          o  200mg/l POLYMER


                                          a  100 mg/l POLYMER


                                          o  50  mg/l POLYMER
                 100       200       300      400

                   SEWAGE CONCENTRATION-(mg/l)

 See example of graph derivation in Appendix.


  Figure 55. Percentage Flow Increase vs Sewage Concentration

            (mg/l) Polyox Coagulant-701 Polymer.
                                                          500
                              100

-------
INCREASE - PERCENT
oo o ro &
> o o o o
ou
O
_J
u_
0
S 40
E
UJ
0
20
n










\
D
\
D





\
\\
A \ \
V
\




o 200 mg/l POLYMER
^ 100 mg/l POLYMER
D 50 mg/l POLYMER


t\
s
\







                 100      200       300       400
                   SEWAGE CONCENTRATION-(mg/l)
See example of graph  derivation in Appendix.

   Figure 56.  Percentage Flow Increase vs Sewage Concentration
             (mg/l) WSR-301 Polymer.

                         101
500

-------
    140
    120
    100
UJ
UJ
o:
o
o
u_
s
E
LLJ
O
                                            0 mg/l SEWAGE
                                         1500 mg/l SEWAGE
                                         2700 mg/l SEWAGE
                 100       200       300       400       500
*                POLYMER  CONCENTRATION-(mg/l)
 See example of graph derivation in Appendix.
 Figure 57.  Polymer (mg/l) vs Percent Increase With a Given
           Sewage Concentration, Polyox Coagulant-701 Polymer.
                               102

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    140
                                        1600 mg/l SEWAGE


                                        2200 mg/I SEWAGE


                                        3110  mg/l SEWAGE


                                        3600 mg/l SEWAGE
                 100       200       300      400
                 POLYMER  CONCENTRATION-(mg/l)
 See example of graph derivation in Appendix.

Figure 58.  Polymer Concentration (mg/l) vs Percentage Flow Increase
          With Given Sewage Concentration, WSR-301 Polymer.
500
                          103

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                              SECTION V

                 FIELD TEST EVALUATION OF POLYMERS
       Field evaluation of the use of polymers in sewerage systems con-
sisted of two separate testing operations.   The first consisted of testing
an existing large-diameter sewer plagued with a  surcharged condition
through the injection of WSR-301 and Polyox Coagulant-70 1 polymers.

       The second field evaluation was the injection of polymers into the
raw sewage at the intake  of a secondary type treatment plant so that data
on its  operation could be  obtained.
Large-Diameter Sewer Field Evaluation

        Full-scale tests were conducted on a 24-inch diameter concrete
sewer line to determine if the use of polymers resulted in flow phenomena
similar  to that  obtained during tests  on a six-inch diameter model line.

        Site Selection.  The selection of the large-diameter test line was
based upon the following criteria:   1) frequency of surcharged flow con-
ditions  from ground-water infiltration, or inadequacy of line capacity dur-
ing peak daily  flows;   2) suitability for installation  of temporary manholes,
suitability for  instrumentation for measuring flow rates, temperature, and
static head on  pipe, and  suitability for obtaining sewage samples for lab-
oratory  analysis;  3) minimum number of branch lines between the point of
polymer injection and the downstream monitoring point  with minimal flows:
4)  ease of access with injection equipment; and  5) availability to lab-
oratory  facilities.

        After considering  a number of potential sites, the most ideal site
was determined to be a 24-inch interceptor sewer line  in the  northern
portion  of the City of Dallas collection system.  This line is constructed
from 24-inch concrete sewer pipe laid at a grade  of 0. 32 percent with the
exception  of about 170 feet which is at a 0. 25 percent grade.

        The 4,  100-foot test section length receives flow from a 36-inch
interceptor line from the City of Richardson and discharges into a 30-inch
diameter pipe downstream.  During peak daily flow periods, this line is
surcharged to depths between four and eight feet above the top of the pipe.
After heavy rainfalls,  the increased  flow resulting from ground-water  in-
filtration is released directly into Cottonwood Creek by a bypass valve.
The frequency  and magnitude of surcharged flow conditions influenced the
selection of this sewer as the demonstration site for field evaluation.

        Site Instrumentation.  Figure  59 delineates the plan and profile of
the pipe section used in  the large diameter flow test demonstration,  in-
cluding the three temporary manholes installed over the 24-inch line and
one manhole installed  over the 36-inch line to permit instrumentation.
                                105

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Figure 59.  Plan and Profile of
           24-Inch Sanitary
           Sewer.

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       The manholes (Figure 60) were constructed by excavating soil
from over the top of the sewer pipe and installing a section of 5-foot
diameter corrugated metal pipe with the bottom end cut to fit the curva-
ture of the sewer pipe.  At each manhole, two 2-inch taps were made in
                  Figure 60.  Monitoring Manhole.
 the sewer pipe and 2-inch pipes inserted.  Concrete was then placed
 around the 2-inch pipes and over the top of the sewer pipe to obtain
 a flat bottom.  By installing valves and fittings,  one of the taps was
 rigged to obtain sewage temperature and sewage  samples and the other
 tap was used to obtain the  fluctuations in static  head on the line.

        Two techniques were used in determining the pressure  or static
 head on the line.  One technique was a simple piezometer constructed of
 transparent plastic tube, of sufficient diameter to eliminate capillary
 action,  fitted in one of the taps so that its end extended below the
 minimum anticipated sewage level in the pipe (Figure 60).
 rose in the tube until equilibrium was reached, and pressure was obtained
 by reading the vertical distance from the meniscus or liquid surface to
 the top of the fitting that held the tube in place.   The elevation of each
 piezometer fitting was obtained and correlated with pipe elevations  by
 field  surveys.  Since the specific gravity of sewage is  near unity,  the
 pressure in feet of water could be read directly at the required timed
 intervals.

         The second technique used a section of six-inch diameter PVC
 pipe fitted onto the sewer line tap to form a float well.  A spring-driven
 water-level  recorder (Figure 61) with horizontal chart drum was then
 installed over the manhole and float well which provided a stati
 stage record versus time.
                                 107

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                 Figure 61. Water Level Recorder.

        Sewage temperature was obtained by periodically observing a
dial thermometer mounted through one of the taps.  Fresh sewage samples
were obtained through a hose bib fitted through the same tap as the
thermometer.

        A number of methods are available for determining flow measure-
ment in pipes or conduits, including weirs,  Parshall flumes, tracer
materials,  and formulas using depth-of-flow and pipe slope.  Because
of the surcharged flow condition and depth of the test section, it was
decided that the use of a  tracer material method would be most practical
and economical.

        This method of flow measurement requires that a tracer be in-
jected into a stream at a continuous and uniform rate of determined con-
centration.  The concentration of tracer material was then measured
downstream from the point of injection after complete transverse mixing
and uniform dispersion through  the fluid had occurred.

       Although many types of  tracers are available for use, a dye,
Rhodamine WT, was used  in this  study.  This dye is essentially non-
toxic,  is rapidly dispersed in water,  is visibly red in concentrations
above 1. 0 mg/1,  and  is not readily destroyed by chemical agents.

       To determine the flow rate, a concentration of 4800 mg/1  of
Rhodamine WT was injected at a uniform rate of 0. 1 gallon   per minute
in manhole "A"  shown in Figure 59.  A fluorometer equipped with an
automatic recorder was used at  the end of the 24-inch test section and
is shown in Figures 62 and 63.  The concentration of dye, proportioned
to the flow rate in the sewer, can be calculated  from the equation:
                                     108

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        Q = q

where Q = Flow rate of the stream.
      q = Flow rate of dye injection in the
          stream at concentration C.
      C = Dye concentration at injection.
      c = Dye concentration at downstream
          measuring station.
Figure 62.  Fluorometer.
                   Figure 63. Fluorometer Recorder.
        In order to obtain a continuous analysis of dye concentration,
 sewage was pumped from the sewer line through the fluorometer.  A small
 centrifugal pump was used and fitted with a one-half inch diameter
 suction probe which extended through a tap in the pipe.  While operating,
 suspended solids in the sewage clogged the probe inlet causing the  pump
 to lose suction,  prohibiting flow monitoring.  Numerous techniques were
 tried to eliminate this operation difficulty;  however, none provided a
 satisfactory solution to this problem.  Because of the plumbing arrange-
 ment necessary to provide  insertion and removal of the probe in the line
 and prevent leakage during high surcharges, screening of the inlet was
 not possible.

        Also, during the periods the pump was not clogged,  the dye con-
 centrations recorded varied widely due to the passage of large  suspended
 solids and small  air bubbles through the fluorometer.  Therefore, to
 determine the dye concentration, the flow-through monitoring mechanism
 on the fluorometer was abandoned in preference of individual sewage
 samples  obtained manually with each sample analyzed separately in the
 fluorometer  This latter method proved to yield more reliable flow data,
 required less operation effort,  and eliminated time gaps during which the
 flow could not be determined because of pump failure.
                                109

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      The concentration of dye in the sewage, c,  was determined by cor-
rections to the fluorometer dial reading.  The normal background reading,
previously determined for the sewage, was subtracted from the dial read-
ing,  which was then modified by a correction factor to compensate for tem-
perature variance between the sewage sample and the calibration sample.
Temperature correction curves for various dye tracers were supplied by the
fluorometer manufacturer. This corrected reading was then converted to
dye concentration by either entering the linear calibration curve  of dial
reading versus dye concentration,  or by dividing the dial reading by the
slope of the line given in the above plot.  If the second method is used,
the previous equation would appear as:

      Q = q   C	  where Rj = the corrected fluorometer dial reading
             Rf                 m = the slope of the plot of R, versus dye
              m                    concentration curve.

      The dye was mixed with water and stored in a 55-gallon drum, which
was  tapped and fitted with a valve and hose connections.   A  small positive-
displacement pump with  3/8-inch piston diameter was used to pump the dye
from this reservoir into the sewer line and is shown in Figure 64. The in-
jection manhole  cover was tapped and a 3/4-inch line fitted through the
tap and connected to the dye pump.  The end of the pipe was fitted with a
5-psi check valve which prevented the water level fluctuations from affect-
ing the rate of dye discharge into the line.
                    Figure 64. Dye Metering Pump.

      A summary of the instrumentation installed at each existing and
temporary manhole is listed in Table XVIII.  Existing manholes are indi-
cated by letters A,  B, and C and temporary manholes by numerals 1, 2,
3, and 4 in Figure 59.
                                     110

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                           TABLE XVIII

             TEST LINE MANHOLE INSTRUMENTATION
Manhole
 Number
Location
Instrumentation
   1      Over 36-inch line 80'
          upstream from Sta.  0 + 00.

   A      Junction of 36- and 24-
          inch lines, Sta. 0 + 00.

   2      Over 24-inch line.  Sta.
          3 + 99.

   3      Over 24-inch line.  Sta.
          6 + 43.

   B      Over 24-inch line at 90
          bend,  Sta. 11+48

   C      Over 24-inch line at 90
          bend,  Sta. 13 + 19.

   4      Over 24-inch line at
          Sta. 15 + 63.
                        Piezometer read manually,
                        temperature and sample.

                        Rhodamine WT and polymer
                        injection point.

                        Piezometer with level
                        recorder.

                        Piezometer read manually,
                        temperature,  and  sample.

                        Piezometer with level
                        recorder.

                        Piezometer read manually.
                        Piezometer with level recorder,
                        fluorometer monitor for deter-
                        mining flow rate and sample.
        Polymer Injection Equipment.  The design and fabrication of a
 polymer injection device was accomplished during the program work, and
 consisted of two separate mobile units.  One unit contained a cone bottom
 tank (Figure 65) with a capacity of 1143  gallons which provided  a  sealed
                      Figure 65. Slurry Mixing Tank.
                               Ill

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container for mixing the polymer into a slurry and holding the polymer in
suspension.  The tank was equipped with piping arranged so that continu-
ous recirculation of the nonsolvent,  isopropyl alcohol, and gelling agent,
klucel H,  could be accomplished as the polymers were added,  to form the
slurry.  This unit was  also equipped with a 55-gallon drum of eel
for flushing the injection lines after each use to prevent the drying and
clogging of the slurry in the lines.  Adequate  flushing of the eductor and
discharge lines was necessary after each injection period.

       The second unit actually contained the injection device (Figure
66) and consisted of a gasoline-driven, centrifugal  sewage pump with a
capacity of 250 gallons per minute,  a six-inch eductor, a rotameter, a
four-inch pipe  and fittings, a flexible suction and flexible discharge line.
                       Figure 66.  Injection Unit.

        The injection unit was connected to the slurry tank by a one-inch
 line fitted with a one-inch magnetic flow meter, recorder and control valve
 to regulate the concentration of polymer released to the test line.
 eductor was used to provide a vacuum on the tank discharge line which,
 coupled with the positive head of the tank, permitted the uniform flow o
 slurry from the tank to be regulated or proportioned by the one-inch
 trol valve.  In operation,  the sewage was pumped from the sewer line
 through the eductor which discharges from the eductor nozzle at a h
 velocity and entrains the slurry from the tank suction line.   The slurry
 and sewage were thoroughly mixed by the turbulence  in the  throat  of the
 eductor and then discharged back into the sewer line.  This flash mixing
 of slurry and sewage reduced the tendency of the highly water-soluble
 polymers to lump or agglomerate  as when slowly added  3 water.

        The slurry mixing tank and the injection unit  are shown with parts
 identified in Figure 67.
                                     112

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I,.,
                                                                 Tank Trailer,  1000 Gallon Capacity
                                                                 Pump, Gasoline Driven
                                                              3  Eductor, 6"
                                                              4  Flowmeter,  1"
                                                                 Base
                                                                 Flowmeter Readout
                                                                 3-Way Valve,  1"
                                                                 Ball Valve,  1"
                                                              9  Butterfly Valve, 4"
                                                             10  Ell, 4" 90 Long Radius
                                                                 Ell, 4" 90
                    Reducer, 4" x 6"
                    Blind Flange,  6"
                    Pipe, 4" x 52" Long
                    Pipe, 4" x 12" Long
                    Suction Hose,  4"
                    Discharge  Hose, 4"
                    Flow Gate, 4"  By Pass Vena Contracta
                    Water Level Indicator
                    Flushing Solvent Tank
                    Slurry Line
                              Figure 67.  Field Injection System With List of Part
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       The injection manhole cover was modified to provide connections
for the suction and discharge lines of the sewage pump and the injector
line (Figure  68).  Inside the manhole, four-inch PVC pipe was installed
                     Figure 68. Injection Manhole Cover at
                               Manhole "A"


between the pressure manhole cover and the flow line of the sewer pipe.
A pressure manhole cover was necessary because  of the  magnitude of
surcharge on the line during peak flows.  The cover was  modified by
cutting holes and welding flanged adaptors to the  cover.   Butterfly valves
and quick-disconnect couplings were attached to the adaptors.  The two
units and operations truck are shown on location in Figure 69.

              Figure 69. Units in Operation at Manhole "A1
                                      114

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       Slurry Composition.   As indicated,  the polyethylene oxides (WSR-
301 and Polyox Coagulant-70 1) are water soluble; however, dissolving
the polymers requires thorough dispersion of the individual resin particles
during the initial contact with water. As the polymer surfaces begin to
absorb water, a cohesive mass is formed that will dissolve only after
prolonged agitation.

       Since adequate polymer dispersion is necessary for complete and
rapid dissolving in water, a method is required for injecting the polymer
into the solvent or water that will keep the  polymers in suspension.  A
nonsolvent that has been  gelled was found to be an effective technique
for injecting the polymers into water.  Anhydrous isopropyl alcohol gelled
with klucel  H formed the nonsolvent gel used in the field evaluation work
on the 24-inch surcharged sewer.

       The  technique of dispersing polymer in a  slurry can be accom-
plished readily and the slurry is  stable for long periods of time (if agitated
daily), which allows use  as need occurs.  When injected into water, the
polymer slurries form aqueous systems  quickly with a  minimum of mixing
or agitation. A complete  discussion of the technique used in mixing the
slurries is given in Appendix D.

       The  slurry used in the 24-inch sewer line demonstration consisted
of 69. 25 percent isopropyl alcohol (nonsolvent), 0. 75 percent klucel H
(gelling agent), and 30 percent polymer.  The current  (April, 1969) unit
costs of slurry components in quantities less than 5,000  pounds are:
isopropyl alcohol,  $0. 69 per gallon; klucel H, $ 1. 30 per pound; WSR-
301 polymer, $0.80 per pound;  or Polyox Coagulant-70 1  polymer, $1.45
per pound.  The cost* of preparing a slurry of WSR-301 is  $216.89 per 100
gallons.  This  material cost  is increased by $ 144.50  per 100 gallons  if
Polyox Coagulant-701 polymer is substituted for the WSR-301 polymer.
Table XIX indicates the material  cost in dollars per hour for injecting the
slurry at 50 mg/1 and 100 mg/1 polymer concentration  at the indicated
wastewater flow rates.

                           TABLE XIX

          POLYMER INJECTION COSTS  -- DOLLARS PER HOUR
Flow
CFS
1. 12
2. 23
5. 57
11 14
16. 71
22. 28
27 85
33.42
MGD
0.72
1.44
3. 60
7. 20
10.80
14.40
18. 00
21.60
WSR-301
50mg/l
$/hi
13.32
26.64
66.60
133.20
199.80
266.40
333. 00
399. 60
100mq/l
$/Hi
26. 64
53.28
133.20
266.40
399. 60
532.80
666.00
799.20
Polyox Coagulant- 701
50 mg/1
$Ahr
21.56
43. 12
107.82
215. 64
323.46
431.28
539. 10
646.92
lOOmg/1
$/hf
43. 12
86.24
215. 64
431.28
646.92
862. 56
1078. 20
1293.84
                                115

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       If the materials are purchased in quantities of greater than 20,000
pounds, the WSR-301 slurry cost can be reduced by 20 percent and the
Polyox Coagulant-701 slurry cost can be reduced by 15 percent.

       Instrument Calibration. Prior to beginning full-scale testing of the
friction-reduction process,  calibration of the fluorometer,  tracer metering
pump,  and level recorders was necessary.

       The fluorometer,  G.  K. Turner Model 111, was  calibrated by using
Rhodamine WT, distilled water, and sewage obtained from the 24-inch test
line.   To convert the relative  fluorometer readings to concentrations of a
fluorescent solute, the instrument had to be calibrated by using prepared
solutions of known dye concentration and determining the relation of fluo-
rometer dial reading, Rf value, to the dye concentration.  A known concen-
tration of Rhodamine WT was diluted in distilled water at a temperature of
72F (base temperature).  Dial readings were observed for the different con-
centrations of dye and a plot  of the  fluorometer  (R ) versus concentration
was developed.

        Before each  field test  was started, the fluorometer dial readings
for sewage without added tracer was monitored to determine the natural
fluorescence of the  sewage (background readings).  Corrections, based
on the background readings and the  sewage temperature, were applied to
the test  data obtained.   Temperatures above the base value create dial
readings higher than actual while temperatures  lower than the base cause
dial readings lower than actual.

        The calculation of flow rate  when using the tracer  method require
the addition of tracer to the wastewater at a uniform and constant rate. To
obtain this, a small positive-displacement pump was used to regulate the
flow of dye at 0. 1 gallon per  minute.  The flow rate was calibrated by de-
termining the volume of dye delivered by the pump during a timed period.

        The magnetic flow meter on the slurry injection equipment was cal-
ibrated by preparing a chart of discharge rate versus polymer concentration
so that the discharge valve could be adjusted to provide the correct dosage
by reading the  magnetic  flow  meter.

        Calibration of the Stevens (Type F) water-level recorders consisted
of setting the recorder with reference to the bottom of a  stilling well of
known elevation with respect  to the flow line elevation of the  sewer at
the installation location.

        Demonstration Test  Procedure.  The line selected for the full-scale
demonstration test was surcharged almost daily, eliminating the need for
predicting periods of peak flow based on rainfall duration and intensity.

        The initial step in conducting a test run was the preparation  of
slurry containing the friction-reduction additive.  After pumping the  non-
                                     116

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solvent into the tank unit of the injector,  the gelling agent was  slowly
added and thoroughly mixed with the nonsolvent by recirculating the two
components through the tank with a positive-displacement pump for a
period of approximately 12 hours to insure even dispersement.  After the
formation  of a gel, polymer was slowly added to the gel while being agi-
tated.  Various refinements in mixing the  polymer  slurry are discussed in
Appendix D.

       The formation of a  slurry was obtained in one to two hours, depend-
ing on the batch size.  Test batches  of over 500 gallons were most  diffi-
cult to prepare. To facilitate the determination of the rate of slurry dis-
charge from the tank through the magnetic flow meter, a small quantity  of
potassium acetate (0.077 percent or about 1. 1 pounds per 200 gallons of
slurry) were added to the slurry to increase the conductivity.  In general,
the mixing procedure usually required about  14 hours of preparation prior
to beginning the test;  however, it should be noted that this time was re-
duced by four to six hours when the procedures described in Appendix D
were used.  The slurry was stable, if agitated periodically, and batches
can be made and stored until needed as an operating practice.

        Prior to beginning the injection of a friction-reducing  polymer,
flow conditions in the 24-inch test line were analyzed to determine if the
static head on the line was increasing or decreasing, at manhole number 1
(because  of increasing or decreasing flow),  and if each observation man-
hole in the test section was surcharged,  but not an excessive amount
(overflowing top of manhole).  If the test parameters were met,  a continu-
ous sample of the wastewater was pumped from the test line through the
fluorometer or individual samples  collected  and analyzed separately for
normal fluorescence determination as required for calibration.   Samples
were  taken from manhole number 4 for analysis of dissolved oxygen, total
solids, settleable solids, pH,  and specific conductance.

        While the  preparatory tasks  were being accomplished, the slurry
was transported to the test site, and the injector and tank units set in
position at manhole A.  The 4-inch flexible  suction and discharge lines
were  connected to the quick disconnect couplings on the modified pres-
sure type manhole cover and on the injector unit.  The tank unit was con-
nected to the injector unit by flexible hose and the pump engine started.
The slurry could then be injected into the line when desired by simply
opening the butterfly control valve on the tank discharge line.

        Prior to actual polymer  injection,  the tracer dye was pumped into
the line and the sewage flow rate  monitored.  Also,  water level readings
were started approximately 30 minutes prior to injection, and the ambient
and fluid temperatures were noted at the various manholes.

        Based on the recorded flow rate in the sewer pipe and the desired
 polymer concentration,  the flow rate  of slurry from the tank was controlled
by the butterfly valve as monitored by the magnetic flow meter.
                               117

-------
       During the first 15 minutes of slurry injection, piezometer read-
ings were taken at 1-minute intervals so that the initial head reduction
could be detected.  After this  period, piezometer readings were taken at
maximum intervals of 15 minutes with the time each reading was taken
being recorded at each manhole. After injecting  for 30 minutes  and 60 min-
utes,  grab sewage samples were taken from manholes 1 and 4,  and compos-
ited for each sample location.

        The slurry was injected until the surcharge was eliminated by re-
ducing the frictional losses sufficiently to carry all of the wastewater with-
in the pipe.  At the termination of polymer injection, piezometer readings
were  taken at 1-minute intervals for 15 minutes  to detect the initial increase
in head, and followed  by readings  taken at 15-minute intervals until the
flow returned to or near the original  surcharged  condition. At this time, a
final  sample was taken from manhole number 4,  completing the demonstra-
tion test procedure.

        Test Results and Analysis. The purpose  of full-scale sewer line
testing was to demonstrate the similarity of flow phenomena and to verify
the results obtained in the six-inch model sewer line tests.  As previously
mentioned, two polymers were tested, WSR-301 and Polyox Coagulant-701
in a gel of isopropyl alcohol and klucel  H.  The slurry contained  30-percent
polymer (by weight) and was injected into the sewer line at concentrations
of polymer varying between 35 and 100 mg/1.  After running  one test  to re-
fine test procedures,  four tests were conducted with each polymer with
varying results and  data reliability.

        Results from these tests confirm the results obtained from the
small-scale test model in that the frictional resistance to flow can be de-
creased to an extent that the  surcharge can be eliminated.

        A typical week-day hydrograph of the flow depth in the line at in-
jection manhole 1 is given in Figure 70.  Tests  were conducted during the
last week of August, the  month of September and  the first week of October;
the period during the year when rainfall  and infiltration of ground water is
minimal in the Dallas, Texas, area. During wet periods, excessive  infil-
tration caused overflow of the monitoring manholes and prohibited the col-
lection of test data.

        Figure  70 is the plot of the sewer hydrographs obtained on the day
WSR-301 was injected into the line  at approximately 80 mg/1 concentration.
The pressure head on  the line was reduced approximately four  feet through-
out the test section during the one-hour injection period.  It is apparent
in Figure 70 that the polymer  injection was started as the flow was begin-
ning  to decrease (indicated by the decrease in  surcharge on the line).  As
a result,  the polymer  reduced the energy required to drive the  now which
was initially 6, 500  gpm.  This flow  rate  was increased during the injec-
tion period but only slightly since the hydraulic gradient decreased  con-
tinuously  as the surcharge dropped.  An explanation of the effects of poly-
 mers on a gravity flow system is given in Appendix B.
                                      118

-------
' i
                       FLOW RATE PRIO
                       TO INJECTION
                       6500 gpm
                                                    AUG. 22, 1968
                                         PERIOD OF POLYMER INJECTION : ONE HOUR
                                         POLYOX  WSR 301, 80 mg/l
                   8A.M.       10          12         2 P.M.       468
                                                        TIME -HOURS
                         Figure 70. Head Reduction Obtained Using 80 mg/l  of WSR-301.
2AM

-------
       Similar hydrographs for each monitoring manhole are shown in
Figures 71 and 72.  It should be observed that at each manhole below
the injection point an increase in head occurred shortly after the additive
was injected and proceeded down the line.  This increase in head was
caused by a transient flow phenomenon resulting from reduced boundary
shear stresses or factional losses in the  sewage.  When the flow volume
in the  24-inch pipe  adjusted to the new flow rate, the head dropped
uniformly along the pipe.

       In Figure 71, polymer injection was again started as the flow
reached  a peak.  As a result, the flow rate was only slightly increased
because of the decrease in both the hydraulic gradient and the volume of
wastewater to be carried by the  pipe.  Similar results were  obtained for
the tests presented in Figure 70, however ,.  in Figure 72, polymer was
injected while the volume of flow was increasing since the  flow history
of the line indicated that peak flow usually occurred between 11:30 a.m.
and 12 noon on week days. As a result of injecting under this condition, a
flow rate increase was  obtained in addition to a decrease in the surcharge
or  static head.   This flow  increase was a result of the reduction in the
frictional resistance to flow provided by the polymers  and the continued
increase in volume of wastewater to be carried in the pipe.

        In each of the tests, injection of polymer was stopped when the
desired  results were obtained (reduction of the head on the line to eliminate
a surcharged condition or a pollution source).

        Analyses of sewage grab samples were  made so that the character-
 istics of the sewage could be determined, should the effectiveness  of the
 friction-reduction additive be considerably less than anticipated (see
 Section III  of this report for effects of sewage  on polymers).  In general,
 the two additives were as  effective as anticipated and only dissolved
 oxygen, total solids,  suspended solids,  pH, specific conductance, and
 temperature tests were made in accordance with the procedures detailed
 in the Twelfth Edition of Standard Methods for the Examination of Water
 and Wastewater. Table XX presents the results  obtained for test runs using
WSR-301 and Poly ox Coagulant-701.

        As a result of full-scale tests on the 24-inch diameter sanitary
 sewer line,  the  elimination of surcharged flow conditions was possible  by
 injecting a slurry containing polymer which reduced shear stresses within
 the fluid and caused a  decrease in the frictional resistance to flow.  The
 reduction of frictional losses in the test section decreased the  static head
 required to drive the inordinate flow,  resulting in the head drops observed
 in the piezometers.

         These same flow phenomena were obtained in the six-inch line,
 tests  conducted in the earlier phases of this program.  In these tests,
 however, a constant flow  rate was maintained and the friction-reduction
 effects  of the polymer were  observed by reductions in static head on the
 line.  Since constant flow conditions were not obtainable in the field test,
 the effects of the polymer slurry were observed by both static head reduc-
 tion and slight flow increases, as described in Appendix B.
                                       120

-------
 PAGE NOT
AVAILABLE
DIGITALLY

-------
              TABLE XX

SEWAGE SAMPLE ANALYSES FOR 24-INCH
        SEWER LINE TEST RUNS
Date
Polymer
Concentration
(mrt/n
\*"3 ' -/
Temperature
(F)
O
Q-
. **
i (
o>
6
 -
j_j ,__) tj>
,
CD
3*3 g
CO COO-
ffi
a

Specific
Conductance
( jj. mho)
POLYOX WSR- 301
Aug.
Aug.
Aug.
Aug.
Aug.
Aug.
Aug.
Aug.
Sept.
Sept.
Sept.
Sept.

Sept.
Sept.
Sept.
Sept.

Sept.
Sept.
Sept.
Sept.

Oct.
Oct.
Oct.
Oct.
Oct.
Oct.
22,
22,
22,
22,
22,
22,
27,
27,
3,
3,
4,
4,

20
20
20
20

27
27
27
27

7,
7,
7,
7,
7,
7,
1968
1968
1968
1968
1968
1968
1968
1968
1968
1968
1968
1968

, 1968
, 1968
, 1968
, 1968

, 1968
, 1968
, 1968
, 1968

1968
1968
1968
1968
1968
1968
0
0
0
80
SO
0
0
75
0
40
0
100

0
50
50
0

0
80
80
0

0
0
35
35
0
0
86
87
86
86
87
87
86
87
85
85
84
84
POLYOX
80
82
82
85

82
82
82
85

78
79
80
80
81
80
6.
4.
7.
5.
7.
6.
7.
9.
6.
6.
8.
8.
0
0
2
8
0
4
2
0
8
8
6
8
897
789
919
957
1133
851
844
1178
912
1258
755
1376
172
146
158
122
102
131
228
226
124
216
134
160
7.
6.
7.
7.
8.
7.
6.
7.
7.
8.
8.
9.
7
8
2
3
4
0
5
0
4
0
4
1
1240
1020
1630
1041
834
1017
953
872
962
862
1513
1103
COAGULANT- 701




"O
CD
<0
-Q

t>
^
(0
(0
Q



















840
980
1120
885

1421
1938
2168
985

620
780
910
1163
852
1160
112
154
185
108

290
386
415
195

148
196
115
230
178
264
7.
7.
7.
6.

6.
6.
6.
7.

6.
6.
6.
6.
7.
7.
2
1
2
9

9
9
8
3

6
8
7
8
4
1
2510
2660
720
1230

1050
880
680
1100

790
825
925
689
768
510
               125

-------
                            TABLE XX

                SEWAGE SAMPLE ANALYSES FOR 24-INCH
                   SEWER LINE TEST RUNS (Continued)
g
f-l
4-"
(0
s-. 
||S
Date
Oct.
Oct.
Oct.
Oct.
Oct.
iperature
uJi S
8,
8,
8,
8,
8,
1968
1968
1968
1968
1968
0
0
45
45
0
^ aw
79
80
79
80
80

p
pjE.
Data Not
Obtained

0 0 g
H WO-
930
1133
860
980
760
. ._  -
-a
0
-o
0 w"^r
W ^H 0>
3 0 g
CO CO v
164
195
132
145
217

ffi
a
7.
7.
7.
7.
8.
ecific
inductance
p. mho)
c
u
0
2
0
1
5
lO-^
1125
1060
739
770
1050
       During the various test runs, slurry injection rates. mg WSR-
301 and Polycx Coagulant-701, were operated between 35 and 100 milli-
orams per mer as shown in Table XXI.  Each concentration used resulted
S a reduction in surcharge, with the smaller concentrations requiring

                              TABLE XXI

             RESULTS OF 24-INCH SEWER LINE TEST RUNS

Time

11:56 AM
12:00 N
12:15 PM

12:30
12:45
12:53
1:00
1:15
1:30
Flow
Rate
(gpm)

6500
6500
6200

-H-
-H-
-H-
*
+
Polymer
Concen-
tration
(mg/1)
August 22,
Start Inj.
80
Approx.
80
Approx.
80
Approx.
80
Stop Inj.
0
0
0
Surcharge Above Top of
in Feet at Manhole
1
2
3
B
Pipe
C

4
1968 - Polyox WSR-301
6.95
6.85
6.30

5.35
3.85
3.25
3.40
3.60
3.85
6.80
6.70
6.20

5.20
3.75
3. 15
3.00
3.65
3.90

"O
0
ro
O
&
ro
ro
O

T3
0
C
(0
4-"
XI
O
ro
4->
to
P

T3
0
-.H
ro
XI
O
ro
ro
P
4.05
A ?o
8.25

3.75
2.45
1.50
-H- -H-
i ,,
1 . DD
1.70
                                    126

-------
          TABLE XXI (Continued)
RESULTS OF 24-INCH SEWER LINE TEST RUNS



Time

2:00 PM
2:15
2:30
2:45
3:00
3:15
3:30
3:45


11:15 AM
11:30
11:45
12:00
12:15 PM

12:30
12:40

9:45
10:00
10:10
10:18
10:28
10:40
10:50
11:00
11:10


10:20 AM
10:35
Polymer
Flow Concen-
Rate tration
(gpm) (mg/1)
August 27,
6000 Start Inj.
6500 75
6000 75
5650 75
-H- Approx.
75
* 75
+ 75
-H- Stop Inj.
September 3,

5600 Start Inj.
6300 40
6700 40
6200 40
-H- Approx.
40
-H- 40
-If Stop Inj.
September 4,
5700 0
5900 Start Inj.
8500 100
8500 100
6400 Stop Inj.
-H- 0
* 0
-H- 0
-H- 0

September 20,
6100 0
6200 0
Surcharge Above Top of Pipe
in Feet at Manhole




1 2 3 B C
1968 - Polyox WSR-301
6.05 6.45 ^ "
5.10 5.35 .S -S
4.15 4.35 2 2
3.45 3.70  O
2.90 3.40 ^
0 0
2.30 2.80 * *
1.85 2.40  
1.70 1.80 Q O
1968 - Polyox WSR-301
-a
5.75 5.95 - g
4.80 4.95 4.80 
3.65 3.85 3.80 -g
2.95 3.30 3.05 Q
2.25 2.55 2.55 ^
^
1.75 1.95 2.05 v
1.45 1.80 1.75 
O
1968 - Polyox WSR-301
3. 70 - 73 -a
3.95 4. 15 g g
3.40 3.80 ' 
2.60 2.70  
2.10 1.65 O O
2.45 2.60 3 -g
3.05 & 2
3. 70 - ro ro
4. 40 ro ro
Q Q
1968 - Polyox Coagulant-70 1
b. 25 5.65 4.80
6.40 5.70 5.05

T3
Q)
-iH
ro
M
O

ro
ro
Q

-a

rH
ro
-1-1
O
o
^
ro
4*
ro
Q

-a
0
a
r-4
ro
X!
O
g
;z;
ro
ro
Q

4.40
4. 70



4

3.40
3.55
3.05
2. 50
2. 20
1.75
* -H-
* -H-



3.40
2. 25
1. 50
-H- -H-

II 11
Tr Tr
-H- -H-


-
3.40
1.80
-tt- *
+ _M_
Tr
1 1 ii
Tr Tr
-
-


3.50
3. 75
                    127

-------
              TABLE XXI (Continued)



RESULTS OF 24-INCH SEWER LINE TEST RUNS


Time

10:50
11:00
11:15
11:30
11:45
12 N

12:15
12:30
12:45
1:00
1:15
1:30
1:45
2:00
Flow
Rate
(gpm)
September
6200
6450
7100
7000
6400
-H-

PM -H-
-tt-
-H-
H-
-H-
5700
5750
5900
Polymer
Concen-
tration
(mg/1)
20, 1968
Start Inj.
50
45
60
50
Approx.
50
Stop Inj.
0
0
0
0
0
0
0
September 27,
10:00
10:15
10:30
10:40
10:50
1 1 :00
11:10
11:20
11:30
11:45
12:00
12:15
12:30
12:45
1:00
AM 6100
6100
6150
6150
6700
7300
7500
7600
-H-
-H-
N *
*
-H-
-H-
5650
0
0
0
Start Inj
80
75
80
Stop Inj.
0
0
0
0
0
0
0
Surcharge Above Top of Pipe
in Feet at Manhole

1



2 3


- Polyox Coagulant-701
6.
6.
4.
3.
2.
1.

1.
2.
2.
3.
3.
4.
4.
4.
1968
4.
5.
5.
. 5.
4.
2.
2.
1.
2.
2.
2.
3.
3.
3.
3.
October 7, 1968 -
10:30
10:45
5850
5950
0
0
3.
3.
80
20
85
50
60
90

80
30
80
25
75
00
20
35
6.
6.
4.
3.
T3 7
Q) ^'
a 2.
to
0 *
z. *
0 2.
Z 3.
2 3.
Q 3.
3.
4.
15
05
55
45
85
25

*
*
85
22
60
85
95
00

B



C



4
(Continued)
5.
6.
4.
3.
2.
1.

0.
1.
2.
2.
2.
2.
3.
3.
20
70
90
60
35
85

70
75
10
25
55
95
10
20
5.
5.
4.
3.
2.
1.

0.
1.
1.
2.
2.
2.
2.
3.
00
75
30
15
15
55

30
60
90
20
50
85
90
00
3.90
5.90
3.55
2.65
II _M_
TT" Tl
* -H-

il II
TT Tr
-H- *
ll ii
Tr Tr
1. 75
1.85
2. 15
2. 25
2.35
- Polyox Coagulant-701
95
30
50
60
35
90
20
45
00
55
90
20
25
25
20
4.
4.
4.
4.
5.
3.
<]) 2.
.5 i.
2 -H-
8 *
-(> " *
>2j 3.
5 3'
fO -1'
Q 3.
35
60
80
95
50
05
70
95
-If
*
85
10
25
25
20
4.
4.
4.
4.
6.
2.
2.
1.
1.
2.
2.
2.
2.
2.
2.
05
30
55
65
00
45
10
35
00
20
35
50
60
60
55
3.
3.
4.
4.
5.
2.
1.
1.
0.
1.
1.
2.
2.
2.
2.
60
80
00
15
70
30
90
35
60
90
95
15
25
30
30






CD
5
(0

J_J
3
(0

Q
 Polyox Coagulant-701
10
90
3.55 3.
4.20 4.
45
00
2.
2.
35
95
2.
2.
10
90
1.65
2. 15
                       128

-------
                     TABLE XXI (Continued)

             RESULTS OF 24-INCH SEWER LINE TEST RUNS


Time

11:00
11:15
11:30
11:45
12 N
12:15 PM
12:30
12:45
1:00
1:15
1:30
1:45
2:00
2:15
2:30
Flow
Rate
(gpm)
October
6050
6100
6200
6500
6850
6850
6300
6150
6000
5850
5700
5600
5500
5400
5250
Polymer
Concen-
tration
(mg/1)
7, 1968 -
0
0
Start Inj.
35
30
35
35
40
35
35
Stop Inj.
0
0
0
0
Surcharge Above Top of Pipe
in Feet at Manhole

1 2 3 B C 4
Polyox Coagulant-701 (Continued)
4.65 4.85 4.50 3.70 3.50 2.75
5.35 5.45 4.95 4.35 4.10 3.25
5.60 5.70 5.20 4.70 4.40 3.50
4.45 4.30 4.25 5.20 3.80 4.15
3.45 3.55 3.45 3.50 2.85 2.40
3.00 3.40 3.35 2.70 2.45 1.85
2.55 3.10 3.15 2.50 2.20 1.75
2.25 2.75 2.80 2.30 2.00 -tf -If
1.85 2.45 2.50 2.15 1.70 -H- -H-
1.60 2.15 2.35 2.00 1.35 -H- -H-
1.45 1.95 2.20 1.80 0.70 -H- -H-
H- + 1.80 -H- -H- 1.05 0.70 -H- -tf
1.65 2.25 1.95 1.55 1.40 -H- -H-
1.85 2.40 2.10 1.75 1.60 -H- -If
2.05 2.50 2.25 1.90 1.70 -H- +
Octobers, 1968 - Polyox Coagulant-701
10:00 AM
10:15
10:30
10:45
11:00
11:15
11:30
11:40
12 N
12:15 PM
12:30
12:45
1:00
1:15
1:30
1:45
2:00
5800
5850
5900
6700
7800
7850
7500
6750
5350
5450
5600
5700
5700
5700
5700
5700
5700
0
0
Start Inj.
45
40
50
45
Stop Inj.
0
0
0
0
0
0
0
0
0
3.55 3.75 3.35 2. 60 2.55 1.95
3.70 3.90 3.50 2.70 2.70 2.10
3.80 4.00 3.55 2.85 2.80 2.20
2.85 3.45 3.00 2.85 2.90 2.75
2.05 2.55 2.35 1.95 1.90 -H- -H-
1.55 2.10 1.85 1.60 1.45 -H- -H-
-H--H- -H--H- -H- -H- 1.30 1.20 -H- *
-H- -If -H- 4f -H- -H- 0.70 0.30 -H- -If
1.65 2.15 1.95 1.45 1.35 -H- -H-
1.85 2. 35 2. 10 1.60 1. 55 -H- -H-
2.00 2.55 2.25 1.70 1.60 -H- *
2.20 2.70 2.40 1.80 1.80 -H- *
2.45 2.90 2.60 1.95 1.95 -If -H-
2.65 3.10 2.75 2.05 2.05 -H- +
2.80 3.20 2.90 2.20 2.15 -H- -H-
2.95 3.35 3.05 2.30 2.25 1.70
3.10 3.45 3.15 2.45 2.30 1.80
-H-   Not able to obtain sample-for fluorometer because of equipment failure.
-H- * Surcharge level below sewer line tap.
                               129

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longer time periods to develop the same pressure head drop that was ob-
tained with the higher polymer concentration.  From such head drop obser-
vations,  it would be reasonable to conclude that extreme surcharged con-
ditions could be eliminated more rapidly by increasing the initial polymer
concentration rate or varying the polymer concentration upward to an amount
that would provide the relief desired.  Both polymers were effective in ob-
taining the desired head reduction, although Polyox Coagulant-701  provided
a more rapid head reduction for the same polymer concentration.

       The mobil injector unit and tank were operated efficiently by one
person, although with modifications the equipment could be made to operate
automatically.
Wastewater Treatment Plant Tests

        Description of Wastewater Treatment Plant. The selection of a treat-
ment plant as a possible test site to measure the effects of polymer addi-
tives on the treatment processes, was conducted by investigating the char-
acteristics of several wastewater treatment plants of cities in the Dallas
Metropolitan Area.  Inspection of the treatment plants was conducted to de-
termine how well each plant would meet the following criteria for a good
test site:

        The treatment plant had to consist of at least a primary clar-
        ification unit, a filtration unit, a digester, and a sludge dry-
        ing bed.

        The treatment plant should be suitable for installation of tem-
        porary flow measuring instrumentation and injection equip-
        ment, and for obtaining sewage samples for laboratory
        analysis.

        The plant should be easily accessible to injection equipment.

        Treatment plants considered for the field test site were in the cities
 of Garland, Piano, Richardson, Carrollton, Mesquite,  and Lewisville,  Tex-
 as.   A summary of the locations investigated along with pertinent informa-
 tion is  shown in Table XXII.

        Investigation of the locations indicated that the Carrollton and
 Lewisville treatment plants would require the  least amount of polymer to
 perform the tests,  because the daily flow rate was the lowest of the plants.
 In addition,  it was determined that the Lewisville plant would require the
 least amount of instrumentation.

        Using this as a basis,  it was recommended that either the Carroll-
 ton or the Lewisville treatment plant be selected as the test  site to measure
 the effect of chosen polymer additives on the treatment process, however,
                                     130

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                             TABLE XXII

                  INITIAL TEST SITES INVESTIGATED
Location  Avail-
City      able
                         Cost of
                         Addi-
                Instru-   tional
       Influent  ments    Instru-
Flow   Line     Already  ments
(mgd)  Size
                    Esti-    Travel
                    mated   Distance
                    Polymer to Plant
In Place   Required   Cost
Miles
Carrollton   yes    0.8   10"

Garland     yes   10.0   48"
                         $12, 334    $  5,446
                Parshall  27,000+   14,630
                Flume
                               10

                               34
Piano
Richardson
Mesquite
Lewisville
yes
yes
yes
yes
1.
2.
--
0.
1
0
-
6
1
5"
18"
15"
-
2
-
1"
Parshall
Flume
Parshall
Flume
Parshall
Flume
Weir
30,
44,
9,
6,
000+
560
163
434
7,
9,
9,
5,
540
420
420
500
10
4
26
25
it was felt that the Carrollton plant might not produce meaningful data and
therefore, was not chosen because considerable sewage was bypassed dur-
ing rainstorms and peak flow periods during the day, and because of the low
efficiency in operation.

        The Lewisville plant lies within the eastern city limits of the city
and south of Garza-Little Elm Reservoir. This plant receives municipal sew-
age through a 21-inch vitrified clay pipe.  The plant is composed of the fol-
lowing units: comminutor.wet wel],and raw sewage pumping station equipped
with one 1000 gall on-per-minute and one 500-gallon-per-minute pump, clar-
igester, trickling filter, and two oxidation lagoons. The 500-gallon-per-
minute  pump serves as a standby unit to handle peak inflow rates.

        The 40-foot-diameter clarigester performs a dual-function.  The top
portion of the unit provides primary sedimentation with a 2-hour detention
period and the lower portion provides  anaerobic digestion of the solids re-
moved in the upper unit.  The digester has a six-inch sludge withdrawal line,
at the bottom, that discharges onto sludge drying beds. Raw sewage is pump-
ed into the  center  of the clarigester two feet below the water surface and
empties radially into the periphery collection trough.  The clarigester is e-
quipped with a surface scum skimmer,  a settled sludge rake, a digester
scum breaker, and a digester sludge rake.

        Secondary  treatment units consists of a 100-foot diameter trickling
filter with a 6-foot sidewall depth with the wastewater applied by a four-
                                 131

-------
arm distributor.  From the trickling filter,  the effluent flows into the oxidation
lagoons.  A schematic  of the plant layout  and piping are shown in Figure 73.

       Site Equipment  and Instrumentation.  Since the Lewis ville  treatment
plant was a straight-line system,  only one flow-measuring device was nec-
essary to measure the flow through all of the units. The desired flow meas-
urement was obtained by adapting  the six-inch  Foxboro Magnetic  Flow Me-
ter,  used during the model sewer line testing, to the 10-inch cast iron clar-
igester influent line.

       The polymer injector used for the 24-inch sewer line demonstration
was  also used for the treatment plant.  Some modifications to the slurry
feed system were necessary before the injector system would feed the proper
rate  of slurry because much larger slurry injection rates were used on the
full-scale sewer line tests.   Slurry injection rates were controlled by a
small-capacity positive displacement pump  driven by a variable  speed
electric motor  instead of the vacuum provided  by the eductor of the injec-
tion  system.  Figure 74 is a schematic diagram that shows the entire injec-
tion  system used in treatment plant testing.

       Since the raw sewage pump had a  capacity greater than the raw
sewage influent rate, the pump operated only 50 to 67  percent of  the time.
An operation time of 80 to 90 percent  appears to be more desirable since
nonsolvent flushing should be held to a minimum.  The raw sewage  pump
discharge was fitted with a  gate valve which allowed some flow adjustment
to the  treatment plant. As part of the  testing procedure, the 1,000 gpm pump
was  throttled to obtain a flow of 700 gallons per minute and a longer opera-
tion time.  The slurry injection rate was set proportionately to the raw sew-
age  pump rate to achieve the proper polymer concentration in the  sewage.

        Polymer Slurries Used. Since the injection pump could only discharge
as low as 0.07 gallon  per minute with any degree  of accuracy,  the polymer
content of the slurry was adjusted so that the injection rate would be in the
more accurate pump range.  For a  polymer concentration of 50 milligrams
per liter in the sewage, a slurry was used that contained 20 percent polymer
powder.  With this polymer  content, the suspension capability decreased
in the  nonsolvent  and therefore, the percentage of klucel  H (gelling agent)
was  increased to one percent to offset the settling conditions.  The solids
content was altered for even lower polymer concentrations.  Table XXIII
describes the type of slurry used for three polymer concentrations and the
slurry  injection rates.

                             TABLE XXIII

               TREATMENT PLANT SLURRY COMPONENTS
Polymer
Concentration
in Sewage
(mg/1)
50
25
10
Polymer
(%)
20
10
10
Slurry Components
Gelling
Agent Non Solvent
(%) (%)
1
1.25
1.25
79
88.75
88.75
Slurry
Injection
Rate
(gpm)
0. 208
0. 208
0.083
                                     132

-------
I,.
 1
                         LEWISVILLE   WASTEWATER
PLANT  LAYOUT

-------
   SLURRY
  RESERVOIR
            VALVE
   SLURRY

    PUMP
    CO
          NONSOLVENT
   EOUCTOR
  UJ
  UJ
  CO
s
I
0.
+
I
111
CO
                          NONSOLVENT
                    PUMP
                                            NON-
                                          SOLVENT
                                         RESERVOIR
                                VALVE
   WET
   WELL
                  WET WELL

                    PUMP

                  ACTUATOR
 RELAY

SWITCH
                              1
                                              1
                           ELECTRIC
                            POWER
                             UI5V)
                                           ELECTRIC
                                            POWER
                                             (II5V)
FIGURE 74- SCHEMATIC OF SLURRY INJECTOR SYSTEM USED FOR
             TREATMENT  PLANT TESTS
                                 134

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       Since cities using the polymer injection system may use one or
several injectors, the test program to determine the effect of the polymers
on treatment plants was designed to be conducted with a range of polymer
concentrations,  and the same two polymers (Polyox Coagulant-701  and
WSR-301) that were injected into the 24-inch sewer line were injected
into the wastewater at the Lewisville treatment plant.

       Wastewater Treatment Plant Test Procedure. Each plant testing
period of 24 hours was separated by at least 48 hours  to allow the plant
time to return,  in general, to normal  conditions.  The  test program  was
designed to have a matrix of nine tests (three tests for each polymer, one
without polymer before the first polymer was injected,  one without  polymer
between the two polymer operations,  and one following the second  polymer
injection).

       A reliable influent hydrograph for an average day was  needed to
determine 1) the quantity of slurry  needed for a 24-hour operation,  2) the
most  desirable time to begin testing  and polymer injection, and 3) when to
take samples and what sample quantities were needed for preparing compos-
ite samples.  Since available influent flow data was lacking influent hydro-
graphs were developed by conducting 24-hour flow studies.  Flow rates
were  computed by utilizing the magnetic flow meter installed, the number  of
on and off cycles of the 1000 gpm  lift pump, wet well dimensions,  and time
required for the sewage level to rise a  determined  distance in the wet well.

        During the plant tests program planning stage,  one complete 24-hour
flow study was  made and a hydrograph plotted. The first flow study was
conducted in December, 1968 (several weeks after any measurable rain)
and was followed by several spot checks at later dates to insure a proper
influent hydrograph.   Two additional 24-hour flow  studies were made follow-
ing heavy rainfall periods that occurred during a break in the  testing program.
One study was made in February,  1969, six days  after extremely heavy rain-
fall.   The results of these two studies differed only slightly.

        The positive displacement  pump was connected to the variable speed
drive  intake hoses, and discharge lines,  and the pump's capacity at various
revolutions per minute was calibrated.  The time required to pump  a known
volume of 20 percent polymer slurry  for each dial setting on the variable
soeed drive, produced a  calibration  curve of discharge rate (gpm) versus
revolutions per minute (rpm).  In addition, a curve of slurry injection rate
versus discharge rate for various concentrations of polymer in sewage was
 plotted to aid in the  proper injector dial selection.

        The evaluation of polymer  effects on sewage and wastewater treat-
 ment was conducted by measuring the parameters that would  yield  the  most
 Significant information on the performance ^^r^^,^"^!*^
 tricklinq filter,  and the oxidation  ponds  such as total solids, dissolved
 soUds  suspended solids, settleable solids,  BOD, COD, dissolved oxygen,
 and pH.
                                 135

-------
        All analyses were made in accordance with the procedures outlined
 in the Twelfth Edition of Standard Methods for the Examination of Water and
 Wastewater.

        Sewage sampling was done in such a manner as to provide the max-
 imum data with a minimum of redundancy in testing.   Five locations along
 the sewage treatment process were chosen to insure selective sampling:

               Wet Well (Station I).  This  point did  not
               have any polymer, and provided raw
               sewage background data.

               Clarigester Inflow (Station II).  Raw
               sewage and polymer mixed.

               Clarigester Outflow (Station III).
               Completion of primary treatment.

               Trickling Filter Outflow (Station IV).
               Completion of first stage of secondary
               treatment.

               Oxidation Pond Outflow (Station V).
               Completion of secondary treatment.

        The tests for dissolved oxygen and pH were conducted at the sewage
 treatment plant during the test runs.  For the remaining tests, composite
 samples were made and refrigerated until testing could be done in the lab-
 oratory.  The time period for composite number one was from 7:30 a.m.  to
 5:00 p.m. ,  since it  was assumed that the raw sewage characteristics would
 remain fairly constant over that period.  Composite number two was obtained
 from 5:00 p.m. to 2:00 a.m. the next morning.  For the remaining time dur-
 ing the 24-hour run (2:00 a.m. to 7:30 a.m.), no samples were obtained
 since recirculation was employed during this period to maintain a satisfac-
 tory operating rate for the trickling filter distributor arm.

        Both composites consisted of five sampling times spaced equally
 apart.   The  quantity of each sample was proportional to the  flow rate at
 the time each sample was obtained, and was proportioned such that the
 total volume of each composite was one gallon as listed in Table XXFV.

        Each test run was begun at approximately eight o'clock in the morn-
ing and terminated 24 hours  later  with polymer being injected for at least
two hours before any samples were taken.  The waiting time before sampling
was based on a retention time study made with dye tracers which showed
that within one hour  after a Rhodamine dye  was placed in the wet well,
traces  of the dye were picked up in the trickling filter effluent.

       After the 1:30 a.m.  sample was taken, the recirculation valve was
opened at the secondary oxidation pond, and periodically increased to
correspond with the decrease in raw sewage influent.   As the influent rate
                                     136

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                           TABLE XXIV


                  TREATMENT PLANT TEST-RUN
                SAMPLING TIMES AND AMOUNTS
   ~~~                     ~  ~  Sample Volume     Composite Sample
Sample Number        Time             (ml)               Number
1
2
3
4
5
6
7
8
9
10
10:00 a. m.
12:00 noon
2:00 p. m.
4:00 p. m.
5:30 p. m.
7:30 p. m.
9:30 p. m.
11:30 p.m.
1:30 a. m.
8:00 a. m.
845
860
830
780
715
870
880
835
485
555
1
1
1
1
2
2
2
2
2
1
increased during the early daylight hours of the morning, the recirculation
was decreased until raw sewage influent rate was sufficient to keep the
plant operating,  usually between 7:00 and 7:30  a.m.  To complete the 24-
hour test the last sample was taken at 8:00 a.m.

        Before each 24-hour test period could begin, a number of changes
had to be made in the plant's operation:  1) if recirculating had been em-
ployed during the night hours, the valve at the  secondary oxidat ion pond
had to be closed; 2) the wet-well pump was  throttled down to 700 gallons
per minute; 3) all sampling locations were cleaned  and the slurry inject ion
system was connected and placed into operation when polymer tests were
conducted.

        To insure proper injection rates  and functioning of the injection
equipment,  surface level readings were taken constantly at the slurry

                                                       
          c

   FiEc^^^
 tie plant was?eturned to normal operating conditions. All composite sam-
 ples were rushed to the laboratory for analysis.
        Test Results and Analysis. The purpose of the wastewater treatment
 tests was to determine what effects the use of polymers in a sewer system
 would have upon the plant's operation and efficiency.
        The testing program was interrupted by an unexpected breakdown
 in the cLrigester sUrrTng mechanism after  one non-polymer run and one
 polymer inaction test (50 mg/D had been completed in January,  1969.
                               137

-------
 The City of Lewisville decided not to repair the malfunction,  but to utilize
 the clarigester as an Imhoff tank since a similar breakdown during the
 summer of 1968 required several months to complete the repairs.  Rather
 than wait for the City to repair the plant,  or select a new treatment plant
 to complete the test program,  the FWPCA  suggested that meaningful re-
 sults might be obtained by using the clarigester as an Imhoff tank.  During
 the interim from plant breakdown to approval to proceed with  testing
 operations (March,  1969) sludge was drained from the clarigester by the
 City.   During this  time, the sewage samples were analyzed  and data
 obtained during the first two runs was evaluated.

         Results of the one polymer injection test completed agreed with
 the results from the laboratory tests, i. e. ,  injecting polymer slurry into
 a treatment plant system did not adversely affect treatment processes.
 On the other  hand,  this one test provided no conclusive  evidence that
 settling rates or filtration rates were improved (percent removal of settle-
 able and suspended solids and BOD  are shown in Table XXV); however,  a
 definite increase in suspended solids was noted.  Performance of the
 clarifier was well below that expected for a primary treatment plant where
 50 to 60 percent of the suspended solids and 30 to 35 percent of the BOD
 should be removed.

                              TABLE XXV

 PERCENT REMOVAL OF APPLIED LOADING IN CLARIGESTER TEST SERIES  1
                        Settleable   Suspended                Polymer
                          Solids      Solids      BOD   Concentration
Non- Polymer
Polyox Coagulent-701
21
20
5
15
19
21
50
        The data for the first two tests are tabulated in Tables XXVI and
 XXVII.  The data indicates very little BOD removal in the trickling filter,
 with the  majority being removed in the oxidation ponds.

      The  second series  of tests were initiated during the middle of March,
1969, after the two flow  studies were performed following heavy rains.  The
treatment  plant had been in modified operation approximately one and a half
months when the second  series of tests began.   The stirring mechanism was
repaired during late February although many of the scum rods had been re-
moved, producing a plant operation that was not the best.  In addition, it
was noted that very little slime or zoogleal growth or film was present on
the rocks  of the trickling filter.  Below is a summary of the tests performed
during the second series:

       1)  Non-polymer:  March 13-14,  1969
       2)  10 ppm of Polyox Coagulant-701: March 24-25,  1969.
                                      138

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                                              TABLE XXVI

                           LEWISVILLE SEWAGE TREATMENT PLANT STUDIES
                                          Non-Polymer Run
                                          Dec. 26-27, 1968
Oo
NO
Sample
Identi-
fication
I
II
III
IV
V

Temp.
(F)
62
61
62
62
58
Total
Solids
(mg/1)
1576
1578
1590
1479
1468
Dissolved
Solids
(mg/1)
1371
1371
1379
1376
1377
Suspended
Solids
(mg/1)
205
207
191
103
91
Settleable
Solids
(mg/1)
228
228
180
168
153

COD
(mg/1)
423
426
315
438
528

BOD
(mg/1)
175
188
152
148
73

D.
1
1
2
4
5

O.
.75
.75
.5
.75
.6

PH
7.4
7.4
7.4
7.7
7.6
                                               TABLE XXVII

                            LEWISVILLE SEWAGE TREATMENT PLANT STUDIES
                              Polymer Run (50 ppm Polyox Coagulant 701)
                                          Jan.  6-7, 1969
Sample
Identi-
fication
I
II
III
IV
V
Temp.
(UF)
61
61
59
59
55
Total
Solids
(mg/1)
1572
1660
1594
1522
1510
Dissolved
Solids
(mg/1)
1450
1482
1458
1440
1473
Suspended
Solids
(mg/1)
142
178
136
82
37
Settleable
Solids
(mg/1)
224
232
185
170
135
COD
(mg/1)
488
828
630
450
146
BOD
(mg/1)
98
168
132
113
53

D.O.
2.3
1.5
1.65
5. 1
2.6

pH
7.4
7. 55
7.4
7.7
7.6

-------
       3) 25 ppm of Polyox Coagulant-701: March 27-28, 1969.
       4) Non-polymer: March 31 and April 1,  1969.

       Analysis of the data disclosed that plant efficiency had not im-
proved any since prior to the breakdown when initial tests were conducted.

       Sludge removed from the clarigester, normally every six to eight
weeks, to the sludge drying beds had the color and odor characteristic of
septic and undigested sludge.  Moreover,  during the testing, strong bubbl-
ing action occurred on the  surface of the clarifier as a result of gases es-
caping from the digester through cracks existing in the  floor of the clarifier.
It was theorized that grease build up in the ceiling of the digester had
plugged  the gas collection chamber and gas could not escape. Also,  over
the years that the  plant has been in existence, the depth of the primary
oxidation pond has greatly reduced from the design depth of three feet, as
islands  of solids deposits  are visible in a number of places.  The percent
removal of settleable solids,  suspended solids,  and BOD are shown in
Table XXVIII.

       A tabulation of the  results of the second series  of tests are given
in Tables XXIX to XXXII.  Results of the second series of tests indicate
trends similar to those found in the first series,  differing only in the raw
sewage loading.  If the most reliable  settleable solids data is averaged
for all the test operations,  the percent removed in the clarifier is 23 per-
cent (7 percent through the trickling filter,  and 16 percent through the oxi-
dation ponds).  The BOD content of the final effluent was lowest for the
last two polymer runs, except for one non-polymer test.  The final COD
content of the effluent, ranged between 140 mg/1 and 170 mg/1, except
for the one non-polymer test,  with the initial clarifier loading in COD
varying from 425 mg/1 to 940 mg/1.

       Although no definite improvements in filtration and sedimentation
rates were detected while injecting the polymer into the sewage,  it should
be noted that no adverse effects developed  under the conditions of polymer
applications at the Lewisville plant.

                             TABLE XXVIII

       PERCENT REMOVAL  OF APPLIED LOADING IN CLARIGESTER
                            TEST SERIES 2
                          Settleable  Suspended           Polymer
                            Solids       Solids    BOD   Concentration
Non-Polymer (l)
Non- Polymer (2)
Polyox Coagulant-701
Polyox Coagulant-701
24
33
30
32
31
24
37
24
34
26
36
2
 
--
10
25
                                     140

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TABLE 300k
LEWISVILLE SEWAGE TREATMENT PLANT STUDIES
Non-Polymer Run: March 13-14, 1969
Sample
Identi-
fication
1-1
l-II
l-III
1-IV
1-V
2-1
2-II
2 -III
2-IV
2-V
c
c I
o n
 III
& IV
<: V

Temp.
(F)
60
59
58
57
56
60
59
60
58
56

60
59
59
58
56
Total
Solids
(mg/1)
1613
1578
1490
1447
1443
1580
1610
1508
1459
1376

1597
1594
1499
1453
1410
Dissolved
Solids
(mg/1)
1445
1417
1389
1368
1370
1389
1413
1420
1416
1371

1417
1415
1405
1392
1371
Suspended
Solids
(mg/1)
168
161
101
79
73
191
197
88
43
5

180
179
94
61
39
Settleable
Solids
(mg/1)
239
251
168
152
146
224
212
185
179
149

232
232
177
166
148

COD
(mg/1)
470
477
394
239
146
532
749
488
279
167

501
663
441
259
157

BOD
(mg/1)
150
200
70
10
30
208
180
180
80
60

179
190
125
45
45

D. O.
(mg/1)
1.8
1.4
2.7
5.8
6.2
2.2
2. 1
3.2
5.2
8.5

2.0
1.8
3.0
5. 5
7.4


PH
7.3
7.2
7.4
7.6
7.7
6.9
7. 3
7. 3
7.6
7.7

7. 1
7.25
7. 35
7.6
7.7

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                  TABLE XXX

LEWISVILLE SEWAGE TREATMENT PLANT STUDIES
 Polymer Run (10 ppm of Polyox Coagulant 701)
             March 24-25, 1969
Sample
Identi-
fication
i-H
Q) T
w II
O TTT
Q. i11
 IV

> I
w II
8, ni
S IV
<3 v

u II
 III
D> IV
<: V
Tejnp.
(F)
58
58
58
57
54
60
59
57
58
54
59
58
58
58
54
Total
Solids
(mg/1)
1528
1659
1392
1262
1273
1428
1419
1434
1363
1259
1478
1539
1413
1313
1266
Dissolved
Solids
(mg/1)
1326
1360
1290
1225
1211
1358
1396
1410
1359
1254
1342
1378
1350
1292
1233
Suspended
Solids
(mg/1)
202
299
102
37
62
70
23
24
4
5
136
161
63
21
33
Settleable
Solids
(mq/1)
248
302
175
135
132
225
244
204
192
134
237
273
190
164
133
COD
(mg/1)
522
818
469
227
162
424
552
421
235
175
473
685
445
231
169
BOD
(mg/1)
80
155
85
25
10
92
120
90
55
15
86
138
88
40
13
D.O.
(mq/'l)
1.3
1.9
2.9
6.5
5.4
2. 1
2.0
2.8
6.3
8.7
1.7
1.9
2. 8
6.4
7.0
pH
7.0
7.4
7. 3
7.4
7.4
7.3
7.4
7. 4
7.7
7. 7
7. 15
7.4
7. 35
7. 55
7.55

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u>
                                                TABLE XXXI

                             LEWISVILLE SEWAGE TREATMENT PLANT STUDIES
                              Polymer Run (25 ppm of Polyox Coagulant 701)
                                          March 27-28,  1969
Sample
Identi-
fication
Composite 1
Composite 2
c
tf
t_i
o
n-i
6>
>
I
II
III
IV
V
I
II
III
IV
V
I
II
III
IV
V
Temp.
(F)
62
63
62
61
61
62
61
63
62
63
62
62
62
62
62
Solids
(mg/1)
1544
1574
1497
1389
1344
1538
1542
1510
1442
1324
1541
1558
1504
1416
1334
Dissolved
Solids
(mg/1)
1337
1415
1391
1342
1305
1344
1383
1422
1431
1317
1341
1399
140?
1387
1311
Suspended
Solids
(mg/1)
207
159
106
47
39
194
159
88
11
7
200
159
97
29
23
Settleable
Solids COD
(mg/1) (mg/1)
240
258
179
175
146
237
249
167
176
137
239
254
173
176
142
547
942
686
446
147
473
947
906
707
135
510
945
796
572
141
BOD D. O.
(mg/1) (mg/1) PH
70
95
65
25
5
50
80
95
55
20
60
86
80
40
13
2. 1
2.5
3.0
5.7
10.4
1.7
2.0
2.2
4.3
12.1
1.9
2.2
2.6
5.0
11.2
7.5
7.6
7.4
7.7
8.0
7.1
7. 3
7.2
7.3
8. 1
7.3
7. 5
7. 3
7. 5
8. 0

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                  TABLE XXXII

LEWISVILLE SEWAGE TREATMENT PLANT STUDIES
   Non-Polymer Run:  March 31 - April 1, 1969
Sample
Identi-
fication
Composite 1

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                              SECTION VI

                ECONOMIC ANALYSIS OF POLYMER USE
       The Keen Branch Basin Sewer in Garland,  Texas,  was chosen for the
economic analysis because of its history of frequent overflow, and because
the City  of Garland had plans for the development of a relief sewer which
would yield specific cost data.

       Figure 75 provides the general orientation of the  study line which
lies in the northwest section of the city where sewer construction requires
rock excavation.  The general slope of the Keen Branch is from west to east
into the Duck Creek outfall sewer.   Geologically, the black plastic clay
soil overlays with a minimum cover of Austin chalk.

       The area  served by the existing sewer is  not presently totally devel-
oped but, after total development occurs, the drainage basin will have ap-
proximately 1393 acres in residential and industrial development and about
304 acres in apartments and commercial establishments  for a total of 1697
acres, or 2. 65 square miles.

       After complete development, design calculations indicate that at the
system's upper end, two  10-inch sewers and  one 6-inch sewer will contrib-
ute to the dual-line system a peak inflow of 4. 1  million gallons  per day.  By
the time the  flow reaches Shiloh Road, the total  flow in  both sewer lines
will be 9. 6 mgd.

        The old  sewer line consists  of 15-inch diameter  clay sewer pipe,
constructed at two different time periods. Initial construction was from
the Duck Creek interceptor to Shiloh Road,  and the secondary construction
was from Shiloh  Road to Yale Drive.  In general, the old sewer invert or
flow-line elevations rose from 521.40  feet at the Duck Creek sewer to
612.85 feet at Yale Drive  or a total rise of 91.45 feet in a length of 13,010
feet for an average slope of 0.0039.

        Existing  lateral connections are such that the two lines are inter-
connected at several locations west of International Street,  but  east of
this area the physiological development of the area and the topography
precluded any interconnections of the two lines.

        The new relief sewer will be constructed of 24-inch, 21-inch, 18-
inch, and 15-inch diameter pipe and will empty  into the Duck Creek out-
fall, downstream from the existing sewer line location.

        The problem section in the existing 15-inch sewer is just west of
Shiloh Road where the minimum slope changes from 0. 0078 to, 0. 00326 for
 a distance of 1136. 6  feet prior to an increased slope of 0.0060.  The old
 sewer, when flowing just full on the 0 00326 slope  has a capacity of
 only 3. 99 cubic feet per  second (cfs), by using  a  selected Manning s  n
 valve of 0.012  based upon the condition and  alignment  of the sewer.
                                145

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                          KEEN BRANCH
                            SEWER
           RELIEF
             SEWER
                                  KEEN BRANCH SEWER
                                   AND RELIEF SEWER
                                 EXISTING SEWER LINE
                                 PROPOSED SEWER LINE
Figure t-5.  Sewer Line Location Used in Cost-Benefit
          Analysis in Garland, Texas.
                          146

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       If the 15-inch diameter pipe in this 1136. 6 foot section is consid-
ered as just overflowing at both the upstream and downstream manholes,
the pipe would have a  capacity of 6. 59 cfs as a result of the increased
slope of the hydraulic  gradient.

       Before considering the specific costs  of the relief sewer and the
polymer injection on an average annual basis, it should be observed that
no attempt was made to economically evaluate the indirect benefits of re-
ducing sewage overflows onto streets  and into creeks.   The indirect eco-
nomic benefits include the reduction of damage from sewage entering homes
and businesses and the elimination of health hazards to individuals and
the community.

       Relief Sewer. The relief sewer was designed to consist of 2698 feet
of 24-inch, 4315 feet  of 21-inch, 3550 feet of 18-inch,  and 2935 feet of
15-inch diameter clay tile pipe as  shown in Table XXXIII.  This table gives
the tabulation of the winning bid for the construction of the sewer.  Grades
on the new line vary from 1. 00 to 0. 40 percent with most of the line located
in the Keen Branch.

       Recently, the City of Garland sold revenue bonds, to be amortized
over a 30-year period  at 5. 7845 percent interest, to finance construction
of several water utility projects, including sewers.  This rate  of interest
and amortization period was  applied to the Keen Branch Relief Sewer to
provide the calculations shown in Table XXXIV.

       The low bid of $394,861. 15 was used in making the calculations
for Table XXXIV,  along with an engineering fee of $21, 717. 36  and an esti-
mate of $6,000.00 for expenses  that the City of Garland would incur for
inspection and other items in conjunction with project construction.  The
resulting cost was  $422, 578. 51,  which was  divided into 29 equal parts
of $14,085.98 and one part  of $14,086.09.  The interest rate was applied
to give the results  shown in Table XXXIV.

       A review  of the City  of Garland maintenance and  operation costs
for 1967-68 yielded that $131,689 was spent on the 279.9 miles of sewers.
The costs averaged $470 per mile  of sewer per year.  Applied  to the  length
of the Keen Branch, its average cost per year will be approximately $ 1202.
Normally,  such a project is  under  maintenance bond for the first year and
maintenance costs  are low in the initial service  years and increase  with
age.  So, by using $ 1202 as an average cost, the annual expenditure would
vary from zero the  first year to about $ 2400 in the thirtieth year.  Therefore,
if a $70 per year increase in maintenance cost is assumed, an operation
and maintenance cost will result as tabulated in Table XXXIV.

        By combining all  costs involved in constructing the new sewer line,
the average annual project cost over a 30 year period is  $27, 309. 98.

        Polymer Injection. Cost  relative to the use of the polymer injection
method of eliminating surcharges in sewers include equipment costs, mate-
rial costs,  and labor costs for both the production of the slurry and the
                                 147

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              TABLE XXXIII




KEEN BRANCH CONTRACT BID TABULATION
Item
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35

36
37
38
39
40
41

Description
6- inch VCT 0'-6'
6-inch VCT 6'-8'
6-inch VCT 8'-10'
8- inch VCT 0'-6'
8-inch VCT 6'-8'
8-inch VCT 8'- 10'
8- inch VCT 10'- 12'
15- inch VCT 0'-6'
15- inch VCT 6'-8'
15- inch VCT 8'-10'
15- inch VCT 10'- 12'
15- inch VCT 12'- 14'
15- inch VCT 14'- 16'
18- inch VCT 0'-6'
18- inch VCT 6'-8'
18- inch VCT 8'-10'
18- inch VCT 10'- 12'
21-inch VCT 0'-6'
21-inch VCT 6'-8'
24- inch VCT 0'-6'
24- inch VCT 6' -8'
24- inch VCT 8'-10'
24- inch VCT 10'- 12'
24- inch VCT 12' -14'
24- inch VCT 14'- 16'
24- inch VCT 16'- 18'
Bore 16- inch CI inc. hole
Bore 18- inch CI inc. hole
Bore 24- inch CI inc. hole
Bore under RR 24- inch CI
24- inch CI CI 150 0'-6'
TY "S" MH Dallas 414-D-7
Std MH 4- foot Dia. 6 feet deep
Extra Depth MH
For special MH at 91 + 00 and
101 + 59
Cut and plug existing sewers
Connect existing MH
Lower 1 2 - inch CI water
Cut and replace culvert floor
Cut and replace asphalt paving
Cut and replace concrete street
paving
Quantity
40 LF
10 LF
15 LF
35 LF
35 LF
10 LF
40 LF
1,800 LF
20 LF
95 LF
320 LF
485 LF
215 LF
3,415 LF
5 LF
25 LF
105 LF
3, 310 LF
1,035 LF
1,660 LF
965 LF
5 LF
10 LF
15 LF
10 LF
33 LF
85 LF
100 LF
85 LF
90 LF
30 LF
27 ea.
8 ea.
57 LF

30 CY
8 ea.
3 ea.
10 LF
160 SY
160 SY

160 SY
Unit Cost Total Cost
$4.75 $
4.75
4. 75
5. 10
5. 10
5. 10
5. 10
16. 75
16.75
19.85
19.85
19.85
19.85
19.30
19.30
19. 30
19. 30
20.85
20.85
23.80
23.80
23.80
23.80
23.80
23.80
23.80
36.00
40.00
47.00
93. 50
19.00
295.00
289.00
20.00

130.00
100.00
200.00
60.00
10.00
13.00

8.00
190.00
47. 50
71. 25
178. 50
178. 50
51.00
204.00
30, 150.00
335.00
1,885.75
6, 352.00
9,627. 25
4, 267. 75
65,909. 50
96. 50
482. 50
2,026. 50
69,013.50
21, 579.75
39, 508.00
22,967.00
119.00
238.00
357.00
238.00
785.40
3,060.00
4,000.00
3,995.00
8,415.00
570.00
7,965.00
2, 312.00
1, 140.00

3,900.00
800.00
600.00
600.00
1,600.00
2,080.00

1, 280.00
                      148

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                       TABLE XXXIII (Continued)
Item	Description	Quantity    Unit Cost   Total Cost

 42   Cut and replace concrete     . 140 SY   $  1.00     $     140.00
         sidewalk
 43   Pea gravel embd.               30 CY      7.00           210.00
 44   Granular Mtl. embd.            50 CY      2.00           100.00
 45   2,000 psi encasement       2.830CY     13.50        38,205.00
 46   Cone backfill excavation    3.220CY     11.50        37,030.00
         rock grout                                       	

                                  TOTAL                 $ 394,861. 15
actual injection of the material.  Costs were not included for vehicles that
would be required since existing vehicles would be available in any water-
utility organization.

       Equipment.  It was determined that a portable injection system would
require one trailer for the injection equipment,  including pump, hose, and
special manhole cover, and one trailer for the slurry tank.  The estimated
cost of injection equipment,  similar to that shown in Figure 66,  is $6100,
and the estimated cost of the slurry mixing tank, Figure 65, is $ 1600. Also,
a modified pressure manhole cover,  Figure 68,  and water level recorder,
Figure 61, facilitate the injection process.  The estimated cost of these
items are $300 and $200  each.   Therefore,  the total cost of the injection
equipment is about $8200.  By using the same cost analysis methods used
in Table XXXIV,  Table XXXV was tabulated. A 5. 7845 percent interest rate
and the estimated maintenance cost were used.  Generally, the equipment
will require some maintenance after each field use and time for this work
has been included in the man hours  of operation.  Also, the equipment was
assumed to have an economic life of 12 years after which the pump,  hoses,
and other parts will probably need replacement.

       The total resulting cost per injection unit was determined to be
$13,983. 14 for an  annual average cost of $ 1165. 26 over a 12-year period.

       Polymer Cost.  Calculations  on the 15-inch diameter sewer indicate
that the capacity of the line just west of Shiloh Road (0.00326 slope) will
carry 3. 99 cubic feet per second when flowing just full.  If the sewer was
overflowing at the upstream and downstream manholes, the flow capacity
would increase to 6. 59 cfs;  however, the systems should  carry 9. 6 million
gallons per day at this location when the total contributory area is com-
pletely developed.  Therefore,  for the polymer injection, it was assumed
that the 15-inch sewer would have to transport the full 9. 6 mgd (14. 8 cfs;
which is 2. 25 times the flow rate available when the upstream and down-
stream manholes are surcharged but not  overflowing.
                                149

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                            TABLE XXXIV




                 KEEN BRANCH RELIEF SEWER COSTS
Year
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Annual
First
Cost
($)
14,085.98
14,085.98
14, 085.98
14,085.98
14, 085.98
14,085.98
14, 085.98
14, 085.98
14, 085.98
14, 085.98
14, 085.98
14, 085.98
14, 085.98
14,085.98
14, 085.98
14,085.98
14,085.98
14,085.98
14, 085.98
14, 085.98
14, 085.98
14, 085.98
14, 085.98
14, 085.98
14,085.98
14, 085.98
14,085.98
14, 085.98
14,085.98
14, 085.98
Interest
on
Bonds
($)
24,444.05
23,626.75
22, 814.45
21,999.64
21, 184.84
20, 370.04
19, 555.23
18,740.43
17, 925.63
17, 110.82
16, 296.02
15,481.22
14,666.41
13,851.61
13, 068.05
12,222.00
11,407.20
10,592.39
9,777.59
8,962.79
8,147.98
7, 333. 18
6, 518.38
5,703.57
4,888. 77
4, 073.97
3,259. 16
2,444.36
1,629.56
814.75
Estimated
Maintenance
And Operation
Cost
($)
0
70. 00
140. 00
210. 00
280. 00
350. 00
420. 00
490. 00
560. 00
630. 00
700. 00
770. 00
840. 00
910. 00
980.00
1, 050. 00
1, 120. 00
1, 190. 00
1,260. 00
1, 330. 00
1,400. 00
1,470. 00
1,610.00
1,680.00
1, 750. 00
1,820. 00
1,890. 00
1,960. 00
2,030. 00
2, 100.00
Total
Estimated
Annual
Expense
($)
38, 530. 03
37,782.73
37, 040.43
36,295.62
35, 550.82
34, 806.02
34, 061.21
33, 316.41
32, 571.61
31, 826.80
31, 082.00
30, 337.20
29,592.39
28,847.59
28, 134.03
27, 357.98
26, 613. 18
25,868.37
25, 123.57
24, 378.77
23, 633.96
22, 889. 16
22,214.36
21,469.55
20, 724.75
19,979.95
19, 235. 14
18,490. 34
17,745.54
17, 000.73
Total   422,578.51    365,710.84
31,010. 00
819,299.35
                                   150

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                              TABLE XXXV

                  PORTABLE INJECTION PLANT COSTS




Year
1
2
3
4
5
6
7
8
9
10
11
12

Annual
First
Cost
($)
683. 33
683.33
683. 33
683.33
683.33
683.33
683. 33
683.33
683. 33
683.33
683.33
683.33

Interest
On
First Cost
($)
474.33
434.80
395. 27
355. 75
316. 22
276.69
237. 16
197.64
158. 11
118. 58
79.06
39. 53

Estimated
Maintenance
Cost
($)
100.00
125.00
150.00
175.00
200.00
225.00
250.00
275.00
300.00
300.00
300.00
300.00
Total
Estimated
Annual
Expense
($)
1, 257.66
1, 243. 13
1, 280.60
1, 214.08
1, 199.55
1. 185.02
1, 170.49
1, 155.97
1, 141.44
1, 101.91
1,062.39
1,022.90
Total  8,200.00
3,083.14
2,700.00
13,983. 14
         During the spring of 1967, observations were made of the 15-inch
line, and it was determined that the line would overflow at one or more
points when the rainfall exceeded 2. 25 inches one day and 1. 19 inches the
following day.  The observation manholes overflowed on the second day
for a four-hour period.

         Table XXXVI shows the critical rainfall when sewer overflows would
likely have occurred for the years 1963 to 1966 (three full years).  The rain-
fall data was taken at Dallas Love Field, which is approximately 15 miles
from the Garland bottleneck site.  Local thunder showers may  occur at Love
Field which do not occur at Garland; however, double mass curve studies
have shown that the long-range rainfall does not differ appreciably.

         An estimate of the time of overflow on the line was made for each
of the storm periods,  based upon the amount of rainfall and the.antecedent
time, which are shown in Table XXXVI.
                               151

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                               TABLE XXXVI

                      ESTIMATES OF POLYMER USE
Year
1963

1964









1965



1966






Month
April

March
May

Aug.

Sept.


Nov.

Feb.

May
Sept.
Feb.
April





Day
21
27
28
8
29
30
15
16
20
21
22
3
4
8
9
10
21
9
23
24
25
28
29
30
Estimated Volume
Number Time of of
Of Rainfall Overflow Flow
Storms (Inches) (Hours) (MG)
1
2

3
4

5

6


7

8

9
10
11
12


13


0.
1.
2.
1.
1.
0.
2.
0.
2.
3.
2.
1.
0.
1.
1.
4.
4.
2.
1.
1.
2.
3.
1.
1.
92
17
39
73
44
59
48
55
17
25
15
76
96
55
82
54
32
32
86
25
33
60
84
02

8
3

1

6
3
8
12

5

8
10
10
6

2
6
8
4
2

3.
1.

0.

2.
1.
3.
4.

2.

3.
4.
4.
2.

0.
2.
3.
1.
0.

200
200

400

400
200
200
800

000

200
000
000
400

800
400
200
600
800
WSR-301
Polymer Pounds
Dosage of
(Mg/1) Polymer

50
50

50

50
50
50
50

50

50
50
50
50

50
50
50
50
50

1,




1.

1,
2,



1,
1,
1,
1,


1,
1,



334.4
500.4

166.8

000.8
500.4
334.4
001.6

834.0

334.4
668.0
668.0
000.8

333.6
000.8
334.4
667. 2
333.6
Average Per Year    4. 33
2.400
50
1,000.8
      The worst flow conditions would occur when the flow of 9. 6 mgd last-
 ed for the entire overflew time period.  By assuming this flow condition,
 and the use of WSR-301 polymer slurry injected at a rate sufficient to pro-
 vide 50 mg/1 polymer concentration, the quantity of polymer for all storm
 overflows totaled 17,014 pounds.   This volume of polymer was converted
 into an annual average quantity by using the approximate average of 4. 25
 storms per year (Table XXXVI).   The annual average polymer use was calcu-
 lated to be 4253 pounds.  By using a unit cost of $0. 80 per pound,  the
 total cost for polymer would be $ 3402. 72 annually.

      Since the slurry is only 30 percent by weight polymer, the  costs of  
 the nonsolvent and gelling agent must be included.  The cost  of isopropyl
                                     152

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alcohol is $0. 69 per gallon or $0. 113 per pound.  The gelling agent cost
$1. 30 per pound.  By combining all material cost and based on a use of
4253 pounds of WSR-301, the annual cost of slurry is $4608. 35.

        Labor Costs. An  intense review of the practice used in the field
tests indicate that about 30 manhours were required to produce a batch of
polymer slurry.  This time also included cleanup and any maintenance
during slurry production.  At an hourly rate of $2. 87, the slurry production
cost would be approximately $366.

        A review of the injection times in Table XXXVI shows that the aver-
age storm duration is 6.  0 hours.  When the 4. 25 average number of storms
per year is used,  the result is 25. 5 manhours per year for injection.  By
again using the $2.87 hourly rate, the annual labor costs for two men is
$146. 37.  Combining all labor costs, a total of $658. 66 annually is ob-
tained.

        When the  annual average mobile injection  plant and equipment cost
of $1165. 26 is  combined with the annual estimated material cost of $4608. 35
and the estimated labor  cost of $658. 66, the annual average cost of in-
jecting WSR-301 to  control flow in the existing 15-inch  diameter Keen Branch
Sewer is $6432. 27. Although certain fixed expenses such as vehicle opera-
tion and general administrational costs were not included, the polymer cost
was only one-fourth the annual average cost of building the relief sewer.
It should be emphasized that one injection system was used in the above
calculations.   However, probably two injection units would be necessary
on occasions.    Therefore, the equipment cost would be twice that in-
dicated with a slight increase in slurry material cost.  If a city antici-
pated using this technique for flow control,  additional units could be
purchased based  on the actual operating performance of an initial single
unit.

        Finally   it must be pointed out that the indirect  benefits of both
 systems were not evaluated because of the difficulty involved in such an
 analysis.

        In  summary, the cost analysis based on construction of a relief
 sewer  line resulted in an average cost of $27, 310 per year.  The cost
 analysis based upon the use of portable  injection equipment and a polymer
 slurry  during peak flow periods was  $6432 per year.
                                153

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                            BIBLIOGRAPHY
       (1)  Sullivan, R.H.,  "Problem of Combined Sewer Facilities
and Overflows. " Tournal WPCFr 41, 113 (1969).

       (2)  Standard Methods for Examination of Water and Wastewater.
12th Ed., Amer.'Pub. Health Assn.,  New York (1965).

       (3)  Maloney, I.E. ,  "Detergent Phosphorus Effect on Algae, "
Tournal WPCF. 38 (1966).

       (4)  Hardenbergh, W.A., Rodie,  Edward R., Water Supply and
Waste Disposal. International Textbook Company, Scranton, Pennsylvania,
pp. 318-349, 372-395  (1961).

       (5)  Clark, John W., Viessman, Warren, Jr., Water Supply and
Pollution Control. International Textbook Company, Scranton,
Pennsylvania, pp. 258-317 (1966).

       (6)  Woldman, Michael L., "Effects of Selected Organic Poly-
electrolytes on Biological System, "  Masters Thesis at Oklahoma State
University in the Department of Environmental Engineering  (May, 1967).

       (7)  Simpson, G.D., Curtis,  L.W.,  "Treatment of Combined
Sewer Overflows and Surfacewaters at Cleveland, Ohio," Tournal WPCF.
41, 151 (1969).

       (8)  Burm, R.J., Krawczyk, D.F.,  Harlow, G.L.,  "Chemical
and Physical Comparison of Combined and Separate Sewer Discharges,"
Tournal WPCF. 40,  112 (1968).

       (9)  Burm, R.J.,  "The Bacteriological Effects of Combined Sewer
Overflows on the'Detroit River,"  Tournal WPCF.  39,  410 (1967).

      (10)  Evans et al, "Treatment of Urban Stormwater Runoff,"
Tournal WPCF. 40,  R162 (1968).
                               155

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           APPENDICES
Appendix A - Fluid Friction Reducing Polymers
             Literature Survey
Appendix B - Discussion of Fluid Modification by
             Polymers
Appendix C - Derivation of Graphs of Percent Flow
             Increase vs Polymer Concentration
Appendix D - Polymer Slurry Mixing Techniques
                  157

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                            APPENDIX A

                FLUID FRICTION REDUCING POLYMERS

                         LITERATURE SURVEY
Western Company Reports

1.  Pruitt, G.  T.; Crawford, H.R.,  "A Study of the Mixing of Drag
Reduction Polymers," Final Report, Contract No. N123(60530)34461A,
Naval Ordnance Test Station, Pasadena, California, October, 1964.

2.  Crawford,  H.R.; Pruitt,  G.T.,  "Drag Reduction of Dilute Polymer
Solutions,"  Symposium on Non-Newtonian Fluid Mechanics I, 56th
Annual Meeting A.I.Ch.E. ,  Houston,  Texas, December 1-5, 1963.

3.  Pruitt, G.T.; Crawford,  H.R.,  "Effect of Molecular Weight  and
Segmental Constitution on the Drag Reduction of Water Soluble Polymers, "
Report No. DTMB No. 1, Contract No. Nonr-4306(00), David Taylor Model
Basin, Washington,  D.C., April, 1965.

4.  Pruitt, G.T.; Rosen,  B.; Crawford, H.R.,  "Effect of Polymer Coiling
on Drag Reduction,"  Report No. DTMB No.  2, Contract No.  Nonr-4306(00),
David Taylor Model Basin, Washington, D.  C.,  August, 1966.

5   Crawford  H.R.   "Method of Reducing Hydrodynamic Drag on Objects
Moving Through Water," U .S . Patent No. 3 ,230, 919 .  Filed 1961(1966).

6.  Pruitt, G.T.; Crawford,  H.R.,  "Drag Reduction Rheology and Capillary
End Effects  of Some Dilute Polymer Solutions, "  Final Report,
Contract No.  60530-8250,  U.S. Naval Ordnance Test Station, Pasadena,
California,  June, 1963.


Supplier Bulletins

7   Properties and Uses:  Cellulose Gum. Hercules  Powder Company,
Cellulose and Protein Products Department,  Wilmington, Delaware.

 8   Pol vox Friction Reducing Agents FRA. Applications Bulletin F-41350,
Union Carbide Corporation, Chemical Division,  270 Park Avenue, New
York, New York 10017, March, 1966.

 9   GaflocRC-61  Technical Bulletin 454-66,  General Aniline and Film
 Corporation, 140 West 51st St. ,  New York,  New York 10020.

10.  TAGUAR. Stein, Hall and Company, Inc., 285 Madison Avenue,
 New York, New York, 1959.
                               159

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11.  Polvox Water - Soluble Resins,  Union Carbide Corporation,  Chemicals
Division, 270 Park Avenue,  New York, New York 10017, 1958 and  1962.

12.  Gantrez AN169 Poly(methyl Vinyl ether/maleic anhydride),  General
Aniline and Film Corporation, 140 West 51st St., New York, New York,
1961.

13.  Separan.  The Dow Chemical Company,  Midland, Michigan,  1961.

14.  Powell, G. M.,III; Bailey, F.E., Jr., Poly (Ethvlene Oxide) Resins.
High Molecular Weight Polymers of Ethvlene Oxide. Research Department,
Union Carbide Chemicals Company, Division of Union Carbide  Corporation,
270 Park Avenue, New York, New York 10017.
Chemical Abstracts

15.  Kozmina, O.P.; Kurlyankina, V.I.; Molotkov, V.A.; Slavetskaya,
P.A., Vvsokomolekul Soedin.  7_(6) 958-61 (1965).

16.  Kimball, G.E.; Cutler, M.;  Samelson, H.,  T. Phvs. Chem. . 56,
57 (1952).

17.  Harris, F.E.; Rice, S.A.. T. Phvs.  Chem. . 58, 725,  (1954).

18.  Rice, S.A.,  Rev. Mod. Phys..  31 (1), 69,  (1959).

19.  Hoppler,  Chem. Ztg..  66, 132  (1942); Kolloid Z. 98,  348 (1942).

20.  Fox,  T.G., Jr.; Fox, J.C.; Flory, P.J.,  T. Am.  Ghem. Soc. 73,  1901
(1951)

21.  Alsherman, F.; Pals, D.T.F.; Herman, J.J., Recueil Trav.  Chem.
Pavs. - Bas.. 71 (1952) 56.

22.  Ripkin, J.F.; Pilch, M.,  N.A.S. Accession No. N65-19091, Rpt. No.
AD 6105 12, 1964.

23.  Tschoegl,  N.W., T. Chem.  Phvs. .  40_(2), 473,  (1964).

24.  Williams,  M.C., Univ. Microfilm,  order No. 64-10, 333;
Dissertation Abstr.  2^(4),  2407-8 (1964).

25.  Adams, F. B.; Whitehead, J.C.; Bogue,  D.C..  A.I.Ch.E. Tournal.
li(6), 1026 (1965).

26.  Astaritaf G.r Ind. End. Chem.  Fundamentals. 4 (3). 354 (1965).

27.  Fox.  T.G.. T. Polvmer Sci. . Pt. C.. No. 9. 35-42 (1965).

28.  Astarita, G.; Nicodemo,  L., Ind. Enq.Chem. Fundamentals. 5.(2),
237  (1966).
                                     160

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29.  Barlow, A.J.; Subramanian, Brit. T. Appl. Phv. . 17_(9), 1201-14
(1966).

30.  Gadd, G.E., Chem. Engr.. 17(2),  46-50 (1966).

31.  Hoyt, J.W., T. Polymer Sci. .  P &  B, 1(10), 713-16 (1966).

32.  Lanaer H.. Kolloid-Z. Z. Polymer. 209(1). 26-33 (1966).

33.  Geller, B.E., Vvsokomolekul  Soedin. .5(11),  1696-701  (1963).

34.  Lange, H., Koiloid-Z. 19_9 (2),  128-35 (1964).

35..  Sheehan, C.J.; Bisio, A.L.,  Rubber Chem. Technol. .  39 (1),
149-92 (1966).

36.  Lodge, A.S.,  Scuola Azione. No.  3, 59-84 (1965).

37.  Mirandaf T.T.. Qffic . Dig.. T. Paint Tec hnol. Eng. . 37(498).
62-96 (1965).

38.  Rohm and Hass, Co., Brit. 1,009,004 (Cl. C 08f.) Nov.  3,  1965;
U.S. Appl. Sept.  7,  1961.

39  Kadyrov, N.;  Mirsalimov, A.; Aripov, E.; Akhmedov, K., Uzbeksk.
Khim. Zh..  8(6), 55-60 (1964).

40.  Saureur, C.,  Ann. Phvs.. 1(506), 271-96 (1964).

41.  Shibayama, K.; Tanaka, T., Kobunahi Kaqaku. 21(235),  690-3  (1964)

42.  Goppel,  J.M., Hhem. Weekblad.  61(1), 13-20 (1965).

43.  Hermans, J.J., T. Polvmer Sci. .  Ft. C No. 12, 51-62 (1966).

44.  Miller, I.F.; Bernstein, F.; Gregor, H.P., T. Chem.  Phys. , 43_(5),
 1783-9 (1965).

45.  Conway, B.E.; Desnoyers, J.E.; Smith, AC., Phi. Trans. Roy.
Snr. London Ger.  A.  251(1074),  389-437 (1964).

 46.  Borchert, O., MfitalLoberflacche. 11(10), 310-12 (1965).

 47.  Christman, R.F., T. Water Pollution Control Federation, 3_8(5),
 685-96 (1966).

 48.  Sridhar,  if r..  T. Sr.i. Ind. Res .. 25(4) 167-71 (1966).

 49.  Weiner, O.J., T- Water Pollution Control Federation. 18(5), 728-33
 (1966).
                                161

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50.  Braun, R., Schweiz Z. Hvdrol..  2l6.(2), 601-27 (1964).

51.  Mancy, K.H.. T. Water Pollution Control Federation. 18(5) / 696-9
(1966).

52.  Knowles, D.J.,  Nucl. Safety. 1(1), 52-6 (1965).

53.  Selleck, R.E., T. Water Pollution Control Federation. 18(5),  714-23
(1966).

54.  Kuznetsova, L.P., Energetick. L4(4), 14-16 (1966).

55.  Kohn, P.G., Svmp. Soc. Exptl.  Biol..  19. 3-17 (1965).

56.  Marten,  J.F., Effluent Water Treat. T..  5.(12), 617-19 (1965).

57.  Burbank,  N.C., Jr., Air. Water  Pollution. 1.0(5), 327-42 (1966).

58.  Collins, R.P., Am. Water Work  Assoc. . 5_8(6),  715-19 (1966).

59.  Goodman, B.L., Water Wastes Ena. . 3_(7),  68-70 (1966).

60.  Chem. Ena. News. 44(42), 40-1 (1966).

61.  Toler, L.G.; Cherry,  R.N., U. S. Geoi. Surv. . Water Supply
Paper No. 1822. 63-5 (1966).

62.  Luskina,  B.M.. Gay. Khromatoa. Sb. . Moscow. 1(3)  89-93  (1965).

63.  Bramer, H.C., Water Sewage Works . 113(8) 275-8 (1966).
                                    162

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                             APPENDIX B

         DISCUSSION OF FLUID MODIFICATION BY POLYMERS
       The chemical and physical changes that polymers impart to fluids
to provide viscous friction reduction cannot be fully explained.  Currently,
the change in flow phenomena that occurs when polymers, such as those
selected for investigation in this program, are added to fluids  is under
intensive research by a number of investigators as indicated in Reference
1.  Basically, previous studies have determined that polymers probably
tend to act as "turbulence dampers" and, in effect, damp out the very
irregular paths of the fluid particles near the wall and extend the laminar
boundary layer further into the turbulent flow core. This damping effect
causes the laminar sublayer to increase in thickness, resulting in a re-
duction in the wall velocity gradient and shear stress gradient which pro-
vides a reduction in the  frictional resistance to flow,  since the action of
wall shear stress is to slow down the fluid near the wall.

       Although this explanation makes the process of friction reduction
by polymers appear less complicated,  it has so far defied complete expla-
nation. Some  of the more obvious  peculiarities  of friction reduction result-
ing from using polymers  are briefly discussed below.

       The Critical Shear Stress.  The shear stress at which a transition
from ordinary  turbulent flow to friction-reduced turbulent flow  occurs, ap-
pears to have to be surpassed before the friction-reducing phenomena will
take place;  therefore, the Reynolds number must be in the turbulent region.

       The So Called  "Diameter Effect. " A polymer of the same concentra-
tion will exhibit different levels of friction reduction in different sizes of
pipe.

       The "Shear Degradation of Polymer Effect. " Some of the most ef-
fective friction-reducing polymers are found to be  adversely affected by
high shear environments such as imparted by some types of pumps.


Basic Characteristics of Polymer Friction Reduction

       How polymers affect a fluid can be better understood by studying
an actual flow curve such as that  shown in Figure Bla and b.   These  graphs,
taken from Reference 2,  show actual pressure drops or frictional losses  for
water with various concentrations  of Polyox Coagulant-701 in a 0.416-inch
diameter pipe. The  higher polymer concentrations  tend to increase the vis-
cosity (the fluid property that causes   shear stress in a moving fluid since,
without viscosity, there is  no fluid resistance).  As a result, a moderate
increase in pressure drop in the laminar flow regime occurs as is  shown
in Figure Bla.  It should be observed that the 2 and 10 mg/1 polymer con-
centrations do not cause friction reduction immediately after transition
from laminar to turbulent flow.  This polymer solution characteristic occurs
                               163

-------
  10
   9 -
   8 -

   -
   6

   1
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o
_ 9
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K
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      I  I  I I I
K  0
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  .01
                                                           	  BASE LINE FOR  WATER


                                                            O  2    WPPM  IN  TAP WATER
                                                            A  10   WPPM  IN  TAP WATER
                                                            X  50   WPPM  IN  TAP WATER
                                                              250  WPPM  IN  TAP WATER
                     '  I  I  I  I I
                                               I   I  I  I I I
                                                      '   '	1  I I  I I
                                                      3   4   56789  10
     .Ot
3  4  98789 0.1
                                               4  5  6789)
                                    VELOCITY,  FT./SEC


                Figure Bla.  Flow Studies in 0.416 Inch I.D. Tubing
                             Tap Water With Indicated Concentrations
                             of Polyox WSR-701.
                                             164

-------
 1000
o
                                                                      1II  I  I 1  I
to
0.
UJ
cz

en
oo
ui
tr
CL
    9

H   
O
                                 ,
                                                           	 BASE   LINE FOR WATER


                                                            O 2    WPPM IN TAP WATER
                                                            A 10   WPPM IN TAP WATER

                                                            X 50   WPPM IN TAP WATER -
                                                             250  WPPM IN TAP WATER
                       5  6  7 8 9 |0
56789 |QO
                                                                            56789
                                   VELOCITY,    FT./SEC.



               Figure Bib.  Flow Studies in 0.416  Inch I.D. Tubing
                            Tap Water With Indicated Concentrations

                            of Polyox WSR-701.
                                     165

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because these solutions reach their critical shear stresses well after the
flow has  transitioned into the turbulent region.

       In Figure Bib,  it is seen that all polymer concentrations are exhib-
iting some friction reduction, although the 50 and 250 mg/1 concentrations
generally provide identical friction reduction (the 50 mg/1) concentration
is near the optimum  concentration for friction reduction in this size pipe
and at these velocities; the  250 mg/1 solution is unnecessarily high for
maximum  obtainable friction  reduction in this flow system).

       The shear degradation phenomenon is also illustrated in Figure
Bib, by the 10 mg/1 solution at flow velocities above 15 feet per second.
This degradation was caused by the shear in the flow system pump, not by
the shear stress  in the pipe.  On the other hand, the solution with 50 mg/1
polymer concentration is unaffected at velocities up to 38 feet per second.
Thus,  it  is apparent that the concentration of sensitive polymers (such as
Polyox Coagulant-701 and WSR-301) must be increased above that normally
required  for optimum friction reduction if passage through a pump prior
to entering a conveyance system will  occur.  In this way, enough of the
polymer will survive the high shear environment to give the desired friction
reduction.  Unfortunately, the additional amount of polymer required to
survive this  high shear environment cannot presently be predicted and must
be determined experimentally.
Flow Control by Using Polymers

        The ways in which some polymers can be used to improve and con-
trol the flow performance of fluids in conduits are illustrated in Figure B2.
In this figure, laminar and turbulent flow curves are illustrated for water
and for water with an optimum concentration of polymer.  In the laminar
region, the water with additive will generally exhibit a slight increase in
frictional losses because of the additive's viscosity effect on the fluid.
In the turbulent  region, the optimum polymer concentration will cause fric-
tional losses to be reduced by 80 to 85 percent  (Reference B). This per-
cent friction reduction is limited by the extrapolated laminar flow line,
since the minimum friction loss  possible is that exhibited by laminar flow.

       The types of flow performance  changes which can be effected by
using polymers to modify fluids  are illustrated by the lines A-B,  A-C, and
A-D  in Figure B2.  One common  way of expressing the flow performance
obtained is percent friction reduction.  Percent  friction reduction, illus-
trated by line A-B,  is defined at a constant flow rate by the ratio of fric-
tional loss or pressure difference at points A, B, and B1. By using such
data points, the percent friction reduction can be calculated by the
equation
                                      166

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CO
CO
o
UJ
cr
CO
O
cc
u.
UJ
UJ
Q.
CD
O
                                   WATER
WATER  WITH OPTIMUM
FRICTION  REDUCTION
ADDITIVE CONCENTRATION
   LAMINAR
     FLOW
                              EXTRAPOLATED
                              LAMINAR FLOW
                              LINE
                                      TURBULENT
                                        FLOW
                   LOG  (FLOW RATE)

   Figure B2. Examples  of Flow Modification of Water by
             Polymers.
                     167

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       The constant flow rate friction reduction indicates that the frictional
losses within a fluid (in turbulent flow) can be reduced up to 85 percent by
using optimum polymer concentration.

       Another common method of expressing flow performance is by per-
cent flow increase, as illustrated by line A-C.  These points illustrate
that the flow rate can be increased (by maintaining a constant energy level
to obviate the friction losses or pressure drop along a pipe system)  up to
140 percent by using an  optimum concentration of polymer  in the fluid
(Reference 1).  This flow increase is defined  as percent flow increase, or
       A better understanding of how polymers can affect a gravity flow
system can be  obtained by considering the following flow system.  Assume
a gravity flow system with two long,  large-diameter sections joined by a
section of moderate length but  of smaller diameter.  During peak flow con-
ditions, the small diameter pipe's  capacity is inadequate to carry the flow,
causing a surcharge or static head  to build up in the upstream section (Fig-
ure B3a).  The total friction loss head, HI, is equal to the sum of the fric-
tion losses in each section of the line, H2 and H3.  The head losses due to
frictional resistance to flow in the  small-diameter section is  assumed to
be sufficient to overflow the upstream section.

       By injecting an adequate concentration of polymer upstream from the
restricted section, the maximum obtainable frictional loss reduction could
be obtained if the flow remained constant; however,  the friction reduction
obtained in the downstream restricted section and large diameter section
will cause the  total frictional head to be reduced to hi! (see Figure B3b).
This reduction  in frictional resistance to flow will cause the flow rate to
stabilize at a somewhat higher rate; i. e. , the flow  adjusts itself from
point A to point D as in Figure  B2.  This point indicates that both a head
drop and a flow increase occurred to obtain a new equilibrium flow con-
dition.
                             REFERENCES
 1.  "Proceedings of the Symposium of Viscous Drag Reduction," Sept. 24
    and 25, 1968, Plenum Press, 1969.

 2.  Pruitt, G. T. and Crawford, H. R. ,  "Effect of Molecular Weight and
    Segmental Constitution  on the Drag Reduction of Water Soluble Poly-
    mers, Report No.  DTMB-1, " prepared for David Taylor Model Basin,
    Hydromechanical  Laboratory, Contract No. NOnr-4306(OD), April, 1965.

 3.  Whitsitt, N.F. , Harrington, L.J. , and Crawford, H. R. ,  "Effects of
    Wall Shear Stress on Drag Reduction of Visioelastic Fluids, Report No.
    DTMB-3, "  prepared for  Naval Ship System Command,  ONR, Contract
    No. NOnr-4306 (W),  June,  1968.
                                     168

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                             Flood   Level
                     a.
                               Flood  Level
                     :. .
Figure B3.  Friction Head Reduction Effects
           Obtained by Using Polymers.
                 169

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                             APPENDIX C

                      DERIVATION OF GRAPHS OF
        PERCENT FLOW INCREASE VS POLYMER CONCENTRATION
       A discussion of how polymers can modify such fluids as water and
wastewater is presented in Appendix B, where it is shown that flow per-
formance can be expressed as 1) percent friction reduction, at a constant
flow rate,  or 2) percent flow increase at a constant energy or static head
level,  or 3) a  combination of both  flow increase and friction reduction,  as
in the case of gravity flow systems.  Also, this discussion explained that
polymers affect fluids by decreasing turbulent flow losses.   Therefore,  by
maintaining a  constant flow rate, a reduction in the head required to over-
come frictional losses will occur;  however, if a constant energy level is
maintained, the flow can be increased until frictional losses again equal
the energy level available to drive the fluid.

       In the six-inch flow tests  conducted during this program, almost
constant water and sewage flow rates were maintained both before and dur-
ing polymer injection;  however, during the period polymer was injected, a
slight increase in flow rate occurred due to the addition of the highly con-
centrated polymer solutions.  To obtain a polymer concentration of 200 mg/1
in a sewage flow rate of 550 gpm,  the necessary injection rate for Polyox
Coagulant-701 and WSR-301 slurries was 23 gpm, resulting in a total flow
rate of 573 gpm.

       Similar slight flow increases were imposed on the 350 and 450  gpm
flow rates  for 50  mg/1 and 100 mg/1,  as  shown in Figures Cl through C6.
These figures  show the measured pressure or friction drop  obtained for the
three flow  rates in the 30-foot test length of six-inch diameter pipe.

       During each test, the pressure drop for turbulent flow was measured
at each of  the three flow rates.  A polymer solution was  then added and the
pressure drop  again determined after steady flow was again obtained at each
flow rate.  These data points  are shown for water and sewage at  73F in the
above figures.  Similar graphs were prepared from data points for each poly-
mer tested.

       To  determine each polymer's effectiveness as a reducer of frictional
losses, the percent flow increase  was determined from graphs (similar to
those shown in Figures  Cl through C6) of various polymer concentrations
(Table XVII presents the test data matrix).

       Figure C7 illustrates how the percent flow increase was derived
from the graphs of flow  rate versus pressure drop.  To avoid extrapolating
beyond the limits of the data obtained,  250 and 300 gpm were selected  for
calculating the flow increase.

       The flow versus pressure drop graphs were entered at 300 gpm,  and
the maximum pressure drop was  determined for this flow  rate (the value at
                                     170

-------
                                           ;
                                       2
                            IIZ
It!

8
3
    50 ppm
                                                 x 100 ppm

                                                    /200ppm
 \
CL
o
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LU
a:
CO

7
                                     ,
                              z
                                 t
   '200            30O        4OO      500
                         FLOW RATE -00/77

        Figure Cl.  Polyox Coagulant-701 in Six-Inch Test

                    Facility at 73F in Water.
                          171

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200
300
                                              700  800  900
                              400      500    600
                          FLOW  RATE- gpm
Figure C2.  Polyox Coagulant-701  in Six-Inch Test Facility at 73F
            in Sewage (3 ml/1 Settleable Solids).
                           172

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     200
300
    400      500     600
FLOW  RATE - gpm
                                                   700  8OO  9OO
Figure C3.  Polyox Coagulant-701 in Six-Inch Test Facility at 73F
           in Sewage (9 ml/1 Settleable Solids).
                           173

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PRESSURE DROP INCHES of WATER for 3O.I FEET
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200 3OO 4OO 5OO 60O 700 800 9OO
                       FLOW  RATE-
Figure C4.  WSR-301 in Six-Inch Test Facility at 70F in Water.
                               174

-------
:
200
300        4OO      5OO    600
        FLOW  RATE  gpm
                                               700  800  900
  Figure C5.  WSR-301 in Six-Inch Test Facility at 70F
             in Sewage (3 mg/1 Settleable Solids).
                      175

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200
300         4OO      5OO    60O   TOO   BOO
       FLOW RATE-  gpm
900
  Figure C6.  WSR-301 In Six-Inch Test Facility at 70F
             in Sewage (9 mg/1 Settleable Solids).
                            176

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             WATER/SEWAGE
   CONSTANT
   PRESSURE
   DROP
 FLOW RATE
 PRIOR TO
 INJECTING
 POLYMER -
            30O
               LOG (FLOW RATE,#*?7)
Figure C7.  Example of Use of Flow Data to Derive
           Percent Flow Increase.
                   177

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the intersection of 300 gpm and the turbulent water or sewage flow line).
At this pressure drop or energy level, a horizontal line was projected to
each of the curves obtained for the various polymer concentration.  At the
intersection of this projected line and the curves, vertical lines were  pro-
jected back to the abscissa to determine the flow rate.   The percent flow
increase was then calculated by the formula


                                             *100f
                              .nn
                              300 gpm

where Qc is the flow rate in gpm for polymer concentration c.  This same
procedure and similar calculation was made for a 250 gpm flow rate for
each of the selected polymers.
                                      178

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                             APPENDIX D

                POLYMER SLURRY MIXING TECHNIQUES
       Rapid dispersion is required to quickly and completely dissolve
water-soluble polymer particles in aqueous  solutions.   The polymer slurry,
when fed into an extreme turbulent regime as occurs in the throat of an
eductor,  was found to be an efficient method of  obtaining polymer disper-
sion without conducting an extensive investigation into numerous mechan-
ical systems.   It was found that the majority of  polymers used during the
six-inch model sewer line testing program could not be  rapidly dispersed
in aqueous solutions when the  polymer was  added in a dry state. Massive
agglomerations occurred and lengthy hydration times were required when
this technique  was used.

       It was determined,  however, that  if polymers were suspended in
a slurry and introduced into an aqueous solution by the  high turbulence of
an eductor,  the hydration time  was  greatly reduced.  In sewer lines where
flow turbulence was present, the total hydration time or solvation process,
using the eductor, was  reduced to a few minutes.

       The process of preparing the slurry involved three major steps: 1)
the nonsolvent (isopropyl alcohol) and the gelling agent (klucel H) were
mixed thoroughly;  2) the nonsolvent and the gelling agent were allowed to
gel; and 3) the water-soluble  polymer was added to the gel to complete the
slurry.  It was important that two precautions be taken  during the slurry
making process:  1) the gelling agent had to be  added carefully to the non-
solvent so that lumps would not form (lumping or agglomeration of the gel-
ling agent in the nonsolvent resulted in much longer gelling times, so a
standard number 5 mesh sieve was used to eliminate lumps); and 2) the
polymer powder had to be added slowly to insure a  more homogeneous
slurry.

       Initially, only very small volumes of slurry were needed for the
six-inch model testing phase of the  program.  These small volumes did
not incur mixing problems,  and it was assumed  that the same mechanical
mixing technique could be applied to larger slurry productions. The prin-
ciple of using a positive-displacement  gear pump as a slurry blending-
mixing device was initially used on the 24-inch sewer line tests. The
nonsolvent was pumped into the portable slurry  tank and the klucel H
added.  Recirculation and blending were accomplished by using a two-inch
positive-displacement gear pump driven by  a variable-speed electric motor.
The polymer was added to the  gel by throttling the recirculation flow while
maintaining a constant pump speed,  creating a slight vacuum on the suction
side of the pump.   This vacuum was used to carry the polymers into the gel.
The gelled slurry was withdrawn  from the  bottom of the  tank and recirculated
back into the top of the tank,  which was  open to the atmosphere.
                               179

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       This technique proved successful only for slurry volumes of less
than 300 gallons.  Between 300 and 500 gallons,  it became increasingly
difficult to achieve a good homogeneous slurry.  Above 500-gallon slurry
quantities, additional mixing devices were required to obtain a gel.  The
polymer powder that did not disperse into the gel before reaching the tank
tended to adhere to other moistened polymer already in the tank, forming
a massive lump of moistened  polymer.  As a result, the gel would flow
around this mass  and not mix with the polymer.  To avoid this,  the  slurry
tank was  equipped with a  two-horsepower mixer to provide thorough
mixing of the polymer and gel.  By using this additional mixing device,
500-gallon batches were gelled in about  12 hours.

       Due to the problems encountered, a modified mixing technique
was investigated  which proved to be effective.  The nonsolvent was
gelled in  two 400-gallon tanks equipped with 1/3-horsepower mixers
operated continuously as the  gelling agent was added to  the nonsolvent.
This procedure reduced the total gelling time and provided a better
quality gel. After six to eight hours, a homogeneous gel was obtained
and transferred into the portable slurry tank unit of the injector. Polymer
was then  slowly added to  the gel,  using the method described previously,
but maintaining constant agitation of the gel as the polymer was added.

       The most efficient method of using polymers in a fluid would be
by adding the polymers in a dry state;  however, additional work and research
will be necessary to perfect and adapt such a method for use in making
large slurry batches.
                                     180

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r,
  BIBLIOGRAPHIC:  The Western Company  of North America.  Polymers
     For Sewer Overflow Control FWPCA Publication No. WP-ZO-22,
     1969.

  ABSTRACT:  Six water-soluble polymers were investigated to deter-
     mine their effects upon aquatic flora  and fauna, flow character-
     istics  of wastewater, and the operation of a wastewater treat-
     ment plant.   It was found that the polymers and gels, in magni-
     tudes tested,  were not  toxic to bacteria,  algae,  or fish,  and did
     not act as a nutrient for algae growth.  Based upon calculations
     obtained from flow test data, a maximum flow increase  of 2.4
     times the flow prior to injection could be obtained if a constant
     head was maintained.   Laboratory flow test data  indicated that
     if flow rates were held  almost constant prior to and during poly-
     mer injection,  a reduction in the static head occurred as a result
     of friction reduction within the fluid. The most effective  polymers
     in providing energy reduction were Polyox  Coagulant-70 1, WSR-
     301, andAP-30;  however, AP-30 required  higher polymer con-
     centrations  to obtain equivalent flow characteristics.  In field
     tests on a 24-inch diameter line,  it was found that polymer con-
     centrations  of between  35 and 100 mg/1, decreased frictional flow
     resistance sufficiently  to eliminate surcharges of more  than  six
     feet.  Based upon an economic analysis,  the average annual cost
     of new construction was approximately five times the cost of us-
     ing polymers during peak storm-flow  periods.
                                                                    ACCESSION NO:

                                                                    KEYWORDS:

                                                                      Polymers

                                                                      Overflow Control

                                                                      Friction Reduction

                                                                      Infiltration

                                                                      Economic Analysis

                                                                      Toxicity Test

                                                                      Sewer Lines
BIBLIOGRAPHIC:  The Western Company of North America. Polymers
   For Sewer Overflow Control FWPCA Publication No. WP-ZO-22,
   1969.

ABSTRACT: Six water-soluble polymers were investigated to deter-
   mine their effects upon aquatic flora and fauna, flow  character-
   istics  of wastewater, and the operation of a wastewater  treat-
   ment plant.  It was found that the polymers and gels, in magni-
   tudes tested,  were not toxic  to bacteria,  algae, or fish, and did
   not act as a nutrient for algae growth.   Based upon calculations
   obtained from  flow test data, a maximum flow increase of 2.4
   times the flow prior to injection could  be  obtained if a constant
   head was maintained.  Laboratory flow test data indicated  that
   if flow rates were held almost constant prior  to and during  poly-
   mer injection, a reduction in the static head  occurred as a result
   of friction reduction within the fluid.  The most effective polymers
   in providing energy reduction were Polyox Coagulant-70 1,  WSR-
   301, andAP-30; however, AP-30 required higher polymer con-
   centrations to obtain equivalent flow characteristics.  In field
   tests on a 24-inch diameter line,  it was found  that polymer con-
   centrations of between 35 and 100 mg/1, decreased frictional flow
   resistance sufficiently to eliminate surcharges of  more than six
   feet.   Based upon an economic analysis,  the average annual cost
   of new construction was  approximately five times  the cost  of us-
   ing polymers during peak  storm-flow periods.
BIBLIOGRAPHIC:  The Western Company of North America.  Polymers
   For Sewer Overflow Control  FWPCA Publication No. WP-20-22,
   1969.

ABSTRACT: Six water-soluble polymers were investigated to deter-
   mine their effects  upon aquatic flora and fauna, flow character-
   istics  of wastewater, and the operation of a wastewater treat-
   ment plant.  It was found that the polymers and gels, in magni-
   tudes tested,  were not toxic to bacteria,  algae, or fish, and did
   not act as a nutrient for algae growth.   Based upon calculations
   obtained from  flow test data, a maximum flow increase  of 2.4
   times the flow prior to injection could  be obtained if a constant
   head was maintained.  Laboratory flow test data indicated  that
   if flow rates were  held almost constant prior to and during  poly-
   mer Injection, a reduction in the static head occurred as a result
   of friction reduction within the fluid.  The most effective polymers
   in providing energy reduction were Polyox Coagulant-70 1,  WSR-
   301, andAP-30; however, AP-30 required higher polymer con-
   centrations to obtain equivalent flow characteristics.  In field
   tests on a Z4-inch diameter line,  it was found  that polymer con-
   centrations of between 35 and 100 mg/1, decreased frictional flow
   resistance  sufficiently to eliminate surcharges of more  than six
   feet.   Based upon  an economic analysis,  the average annual cost
   of new construction was approximately five times the cost  of us-
   ing polymers  during peak  storm-flow periods.
                                                                       ACCESSION NO:

                                                                       KEY WORDS:

                                                                         Polymers

                                                                         Overflow Control

                                                                         Friction Reduction

                                                                         Infiltration

                                                                         Economic Analysis

                                                                         Toxicity Test

                                                                         Sewer Lines
                                                                        ACCESSION NO:

                                                                        KEY WORDS:

                                                                         Polymers

                                                                         Overflow Control

                                                                         Friction Reduction

                                                                         Infiltration

                                                                         Economic Analysis

                                                                         Toxicity Test

                                                                         Sewer Lines
                                                                                            _J

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