EPA-660/2 73 028
DECEMBER 1973
Environmental Protection Technology Series
Coliform Bacteria Growth And Control
In Aerated Stabilization Basins
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55
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Office of Research and Development
U.S. Environmental Protection Agency
Washington, D.C. 20460
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and
Monitoring, Environmental Protection Aqency, Ivave
been grouped into five series. These five broad
categories were established to facilitate further
development and application of environmental
technology. Elimination of traditional grouping
was consciously planned to foster technology
transfer and a maximum interface in related
fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
U. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL
PROTECTION TECHNOLOGY series. This series
describes research performed to develop and
demonstrate instrumentation, equipment and
methodology to repair or prevent environmental
degradation from point and non-point sources of
pollution. This work provides the new or improved
technology required for the control and treatment
of pollution sources to meet environmental quality
standards.
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EPA-660/2-73-028
December 1973
COLIFOEM BACTERIA GROWTH AND CONTROL
IN AERATED STABILIZATION BASINS
By
S. H. Watklns
Project 12040 GQD
Program Element 1BB037
Project Officer
Dr. Martin D. Knittel
Pacific Northwest Environmental Research Laboratory
National Environmental Research Center
Corvallis, Oregon 97330
Prepared for
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20406
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ABSTRACT
The State of Oregon has a standard of 1000 coliform bacteria (coliforms)
per 100 ml for recreational waters. Secondary effluent from a sulfite
mill in Lebanon, Oregon, consistently had the potential to increase
the coliform population in the South Santiam River to concentrations
greater than 1000 per 100 ml. This provided an opportunity to
determine factors responsible for high coliform levels in an industrial
waste and to develop methods for reducing their numbers. The high
concentrations of coliforms in Lebanon effluent were not due to their
growth during secondary treatment but rather reflected development
at earlier stages. In a small scale system, coliforms were reduced to
acceptable levels in a secondary treatment unit by killing them in
the incoming wastes. Methods for accomplishing this on a full scale
were not found, therefore disinfection was investigated as an
alternative. A modified chlorination system which employed caustic
injection into the chlorinator's water supply was the most effective
treatment tested. The ability of the process to reduce coliforms to
acceptable levels in the South Santiam River was demonstrated. Chemical
analyses and fish bioassays showed that the process would not contribute
toxic chlorine residuals to the receiving waters. Rapid methods for
estimating colicidal activity are described. Factors which affect
coliform populations in mill systems and those which affect chlorine
activity are discussed.
This report was submitted in fulfillment of Project Number 12040 GQD by
Crown Zellerbach Corporation under the partial sponsorship of the
Environmental Protection Agency. Work was completed as of November 31,
1972.
ii
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CONTENTS
Page
Abstract ii
List of Figures iv
List of Tables ix
Acknowledgments xvi
Sections
I Conclusions 1
II Recommendations 7
III Introduction 9
IV Apparatus and Methods 10
V Evaluation of Methods for Enumerating Coliforms 17
VI Bacteria in Aerated Stabilization Basins 34
VII Effect of Variables on Concentrations of Bacteria
In Secondary Effluent 42
VIII Role of Coliforms in BOD Reduction 89
IX Sources of Coliforms 92
X Activity of Chlorine in Secondary Wastes 99
XI Full Scale Chlorination 140
XII Fate of Chlorine Added to Secondary Effluent 191
XIII Fish Toxicity of Chlorinated Effluents 201
XIV Evaluation of Miscellaneous Bacteriocides 218
XV References 222
XVI Glossary 224
XVII Appendices 226
XVIII Index 273
iii
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FIGURES
No.
1 Comparison of Methods for Enumerating Coliforms in
Unchlorinated Mill Wastes 19
2 Comparison of Methods for Enumerating Coliforms in
Chlorinated Effluent. Mill Trial of September
29, 1971 22
3 Comparison of Methods for Enumerating Coliforms in
Chlorinated Effluent. Mill Trial of October 26,
1971 23
4 Comparison of Methods for Enumerating Coliforms in
Chlorinated Effluent. Laboratory and Mill Trials
of March 16, 1972 24
5 Comparison of Methods for Enumerating Coliforms in
Chlorinated Effluent. Laboratory and Mill Trials
of March 17, 1972 25
6 Reproducibility of Coliform Counts Using the Membrane
Filter Method 27
7 Evaluation of WL Nutrient Medium for Enumerating
Coliforms and Other Bacteria in Mill Waste 32
IV
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No. Page
8 Prosthecate Bacteria in Lebanon Secondary Effluent 39
9 Bacteria in Secondary Effluent. Approximate
Magnification 1600 X 41
10 Concentrations of Bacteria in Secondary Influent
During Parallel Operation 44
11 Concentrations of Bacteria in Secondary Effluent
During Parallel Operation 45
12 Small Scale Waste Treatment System 50
13 Main Stages of Small Scale Treatment System 51
14 Effect of Inoculation on Coliform Concentrations in
Effluents from Small Scale Treatment Units 54
15 Comparison of Concentrations of Bacteria in Mill
and Small Scale System 57
16 Flow of Mill Wastes 59
17 Relationship Between Secondary Effluent Temperature
and Coliform Concentrations 64
18 Dissolved Oxygen and pH of Waste in Pond 1 65
19 Dissolved Oxygen and pH of Waste in Pond 2 66
20 Relationship Between BOD and Coliform Concentrations 77
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No. Page
21 Coliform Concentrations During Series and Parallel
Pond Operation 80
22 Oxygen Uptake by Secondary Effluent from Series and
Parallel Pond Operation 83
23 Effect of Retention Time on Coliform Concentrations
in Small Scale Treatment Units 86
24 Recycle in High Yield Pulping System 94
25 Recycle in Regular Sulfite Pulping System 96
26 Bactericidal Activity of Chlorine in Secondary Effluent 101
27 Chlorine Uptake by Secondary Effluent. Laboratory
Chlorination 102
28 Effect of Dilution on Chlorine Activity 104
29 Effect of Chlorine on Oxygen Uptake by Secondary
Effluent at Various pHs. Ill
30 Effect of pH on Inhibition of 0~ Uptake by Chlorine 114
31 Relationships Between Applied Chlorine and 5 Minute
Residuals in Secondary Effluent. Effect of pH 121
32 Relationships Between pH and Chlorine Species in
0.1 N Solutions 122
vi
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No.
33 Effect of pH and Initial Chlorine Concentration on
Reaction Rates of Chlorine with Secondary Effluent 125
34 Effect of pH on Disappearance of Chlorine Residuals
in Secondary Effluent 128
35 D.O. Uptake and Sulfite Oxidation by Mixtures of
Secondary Wastes 133
36 Effect of Effluent Concentration on Chlorine Uptake 138
37 Mill Secondary Effluent Discharge and Chlorination
Systems
141
38 Effect of Caustic Addition on Chlorine Uptake by
Secondary Effluent. Mill Chlorination. 145
39 Effect of Caustic Addition on Chlorine Residuals
Obtained from Mill Chlorination of Secondary
Effluent 147
40 Apparatus for Ammonia Addition to Chlorinator Water
Supply 152
41 Effect of Chlorination on Concentrations of
Coliforms in Mark Slough 183
42 Reduction of Coliform Concentrations in the South
Santiam River Due to Chlorination of Secondary
Effluent 185
43 Effect of Chlorination on D.O. in Mark Slough 187
vii
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No. Page
44 Effect of Chlorination of Secondary Effluent on D.O.
Concentrations in the South Santiam River 189
45 Effect of Total Residual Chlorine on Oxygen Uptake
by Secondary Effluent 198
46 Apparatus for Evaluating Toxicity of Chlorinated
Effluents 211
47 Schematic of Apparatus for Evaluating Toxicity of
Chlorinated Effluents 212
V1L1
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TABLES
No.
1 Comparison of Membrane Filter and Multiple Tube
Methods for Enumerating Coliforms in Unchlorinated
Mill Wastes 18
2 Comparison of Membrane Filter and Multiple Tube
Methods for Enumerating Coliforms in Chlorinated
Secondary Effluent 20
3 Reproducibility of the Membrane Filter Method for
Enumerating Coliforms 28
4 Evaluation of a Plate Count Procedure Using WL
Nutrient Medium for Enumerating Coliforms 31
5 Characteristics of Secondary Composite Effluent
During Parallel Operation. Summary of Data. 34
6 Variations in Bacteria in Secondary Effluent During
Parallel Pond Operation 36
7 Differential Microscopic Counts of Secondary Influent
and Effluent 37
8 Characteristics of Secondary Influent. Summary of
Data 42
ix
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No. PaSS
9 Variations in Bacteria in Secondary Influent
During Parallel Pond Operation 46
10 Effect of Secondary Treatment on Concentrations of
Bacteria ^7
11 Components of Small Scale Waste Treatment System 52
12 Effect of Inoculum on Bacterial Concentrations in
Small Scale Secondary Treatment Units 55
13 Effect of By-Product Manufacture on pH of Mill Waste
Used in Evaporator "Water Leg" 60
14 Effect of pH on Concentrations of Coliforms in Mill
Wastes Stored at 2ฐ C. 61
15 By-Product Evaporator Operating Schedule
62
16 Effect of Dissolved Oxygen Concentration on
Bacteria in Pond 1 67
17 Effect of Dissolved Oxygen Concentration on
Bacteria in Pond 2 68
18 Effect of Dissolved Oxygen Concentration on Bacteria
in Small Scale Aeration Units 70
19 Comparison of Bacterial Concentrations in
Secondary Influent and Effluent 72
20 Concentration of Bacteria in Secondary Effluent From
EPA Unit and Mill Aeration Basins 73
x
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No. Page
21 Bacterial Concentrations in Settling Stages of
Small Scale Units 74
22 Comparison of Secondary Effluent Characteristics
From Series and Parallel Pond Operation 78
23 Oxygen Uptake and Sulfite Oxidation by Mixtures of
Secondary Influent and Effluent 81
24 Oxygen Uptake by Secondary Effluent Samples from
Series and Parallel Operation 82
25 Effect of Retention Time on Characteristics of
Effluent from Small Scale Unit 85
26 Effect of Retention Time on Characteristics of
Effluents from Small Scale and Mill Aeration Units 87
27 Relationship Between Coliform Concentrations and
BOD of Effluents from Small Scale System 90
28 Concentrations of Bacteria in Mill Drains 92
29 Concentrations of Bacteria in Mill White Water and
Treatment Systems 95
30 Concentrations of Bacteria in Mill Water Supply 97
31 Effect of Time on Destruction of Bacteria by
Chlorine. Mill Trial of September 28 with 7 ppm Cl 99
xi
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No.
32 Effect of Chlorine Concentration on Destruction of
Bacteria. Mill Trial of September 29 100
33 Effect of Dilution on the Bactericidal Activity of
Chlorine to Secondary Effluent. Mill Trial of
10-26-71 with 9.1 ppm Initial Chlorine 105
34 Effectiveness of Mill Chlorination System 106
35 Comparison of Methods for Evaluating Chlorine
Activity. Oxygen Uptake, Bacterial Motility and
Membrane Filter 108
36 Comparison of Methods for Evaluating Chlorine
Activity. Chlorine Residual, Bacterial Motility,
Membrane Filter and Multiple Tube 110
37 Effect of pH and Chlorine on Oxygen Uptake by
Secondary Effluent and on Bacterial Motility 112
38 Effect of pH on Total Chlorine Residuals in Secondary
Effluent. Application Rate 10 ppm 116
39 Chlorine Required to Produce 5 Minute Residuals in
Effluent at pH 1.7 and 7.0 117
40 Effect of pH on Chlorine Uptake by Secondary
Effluent. Application Rate 50 ppm 118
41 Effect of Chlorinating Solution pH and Effluent pH
on Chlorine Residuals in Secondary Effluent 120
Xll
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No. Page
42 Effect of Chlorine Concentration on Reaction Rates 126
43 Effect of Anaerobic Incubation on Chlorine Activity 130
44 Chlorine Uptake by Secondary Wastes and by Sulfite 131
45 Comparison of Chlorine Uptake by Secondary Effluent
and Glucose 136
46 Chlorine Uptake by Particulate and Soluble Components
of Secondary Effluents 137
47 Relationship Between Effluent Concentration and
Chlorine Uptake 139
48 Effect of Mill Chlorination on Bacterial Motility
and Coliforms. Summary of Data. 142
49 Use of Caustic in Chlorination Systems. Summary
of Mill Evaluations 143
50 Effect of NaOH Addition Rates on Chlorine Residuals 149
51 Estimated Neutralization Costs with NaOH and NH3 151
52 Evaluation of Ammonia as a Neutralizing Agent--
Summary of Mill Experiments 153
53 Motility and Growth Characteristics of Potential
Indicator Bacteria 157
XJ.11
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No. Page
54 Apparent Chlorine Residuals in Unchlorinated
Secondary Effluents 159
55 Effect of Ferric Iron and Nitrate on the Test for
Total Residual Chlorine 160
56 Effect of D.O. Concentration on the Formation and
Removal of Nitrite in Secondary Effluent 162
57 Factors Affecting Nitrification 164
58 Variations in Ultraviolet Absorbance and Flow Rates
of Secondary Effluent 167
59 Chlorine Requirements of Ponds 1 and 2 in Series
Operation. 9/16/72 168
60 Mill Chlorination of Secondary Effluent from Series
Operation With and Without Caustic Addition 170
61 Summary of Full Scale Chlorination Monitoring Data 177
62 Characteristics of Effluents with 2 Hour Chlorine
Res iduals 180
63 Effect of Chlorination on Receiving Waters. Summary
of Data 182
64 Instrument Settings for Chlorine Determinations 193
65 Recovery of Chlorine Added to Secondary Effluent 194
xiv
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No. Page
66 Effect of Total Residual Chlorine on Microorganisms 196
67 Stability and Bactericidal Activity of Total
Residual Chlorine 200
68 Effect of Chlorination on the Toxicity of Secondary
Effluent Toward Guppies in Aerated Samples 203
69 Effect of Chlorination on the Toxicity of Secondary
Effluent Toward Guppies in Non-aerated Samples 204
70 Relationship Between Effluent pH and Concentrations
of NH4+ and NH4OH 206
71 Toxicity of Hypochlorous Acid and Monochloramine to
Guppies 207
72 Inactivation of Chlorine Toxicity by Effluent and
Chlorinated Effluent 209
73 Continuous Flow Fish Toxicity Tests. Summary of
Data 215
74 Comparison of Chlorine Dioxide and Sodium
Hypochlorite 2l9
75 Effect of Ozone on Bacteria
221
xv
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ACKNOWLEDGMENTS
The project was initiated by Dr. Herman Amberg, Director of Environmental
Services at Crown Zellerbach, Caraas, Washington. He also was project
leader for the company.
Most of the experimental work at the Lebanon mill site was done by
S. H. Watkins, Research Microbiologist and by John Esch, Laboratory
Technician, both of Environmental Services. The latter took up
residence at Lebanon and contributed the dedication and continued effort
essential to the completion of the many phases of the project.
Ozonation trials were made by Mr. John Barton Jr. during his vacation
from the University of South Dakota Medical School.
Analyses of treated effluents for various forms of chlorine were made by
Dr. James Bearss of Crown Zellerbach's Central Research Division.
Drafting was done by Mr. Charles Esser of Environmental Services.
Typing was done by Mrs. Evelyn Hamblen who also provided much needed
help in proofreading, organizing and editing the report.
Mr. A. C. Moncini of the Lebanon mill was responsible for the installation
of the chlorinator.
xvi
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During the course of this study Progress Reports were given semi-monthly
to a diverse group. This resulted in a stimulating exchange of ideas
and presentations of viewpoints which were of considerable benefit. The
author thanks the following for their participation:
Environmental Protection Agency:
Dr. Martin D. Knittel
Mr. Ralph Scott
Dr. Kirk Willard
National Council for Air and Stream Improvement:
Mr. Andre Caron
Mr. Eben Owens
Oregon State Department of Environmental Quality:
Mr. Ed Quan
Dr. Warren Westgarth
University of Washington:
Dr. Erling Ordal
Crown Zellerbach, Lebanon Mill:
Mr. Ken Byington
Mr. Ed Lownik
Mr. Elmer Mays
Crown Zellerbach, Environmental Services:
Dr. Herman Amberg
Dr. Thomas Aspitarte
Mr. John Esch
xvii
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Andre Caron and Eb Owens of the National Council for Air and Stream
Improvement provided helpful advice and assistance. It was appreciated
very much.
Good control of effluent and water flow rates was an essential require-
ment for the project. The advice and assistance of Mr. George Chadwick,
Oregon State University, were very helpful in this area.
Thanks are extended to Dr. E. J. Ordal and J. T. Staley for providing
information on prosthecate bacteria and to the latter for supplying
photomicrographs.
The financial support of the Environmental Protection Agency is gratefully
acknowledged. In addition we enjoyed a beneficial association with
members of the Agency including Dr. Martin Knittel, Project Officer,
Mr. Ralph Scott, Dr. Kirk Willard and Mr. John Ruppersburger. Dr.
Jerry Bouch of the Fish Toxicology Laboratory kindly supplied salmonid
fingerlings along with good advice which enabled us to use them
satisfactorily.
Kviii
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SECTION I
CONCLUSIONS
1. Both the Multiple Fermentation Tube (MT) and Membrane Filter (MF)
methods are satisfactory procedures for the study of coliform growth
and the dynamics of disinfection. The latter procedure is preferable
because it is more precise and requires less time and equipment.
2. Compared to the MF method, the MT procedure gives somewhat higher
values for coliform concentrations in chlorinated and unchlorinated
secondary effluent. If coliform data is relevant to pollution abatement
standards, the MT technique should be used or the suitability of
alternate methods should be established.
3. Without further treatment, secondary effluent from the Lebanon mill
has the potential for consistently increasing coliform concentrations
in the South Santiam River to more than 1000 per 100 ml. The mean
coliform concentration of 107 effluent samples was 25 million per 100 ml.
4. Colifortns do not proliferate in the secondary ponds. Averaged over
a 15 month period their concentrations were considerably greater in
wastes before secondary treatment.
5. Conditions which are conducive to coliform growth include recycling
of high BOD materials within the mill, extended storage within the mill
and in primary treatment, and the accumulation of sediments. Coliforms
in the raw water supply are a continuous source of inoculum.
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6. Coliforms are not necessary for the secondary treatment of sulfite
mill wastes. In effluent from the aerated basins they represented
less than 2 percent of the total bacterial population and in a small
scale system good BOD reduction was achieved when coliforms were less
than 0.0005 percent of the total bacteria,
7. The most important factor which influences coliform concentrations
in secondary effluent is the number of coliforms added to the aeration
basins, i.e. inoculation. Changes in coliform populations in secondary
effluent reflected those which occurred in the influent. In a small
scale aeration unit coliform concentrations were reduced by more than
99 percent by killing coliforms in the influent.
8. Pretreatment to kill coliforms may be a practical way to obtain
secondary effluents with acceptable levels of coliforms. Methods could
include heating and selective chlorination of wastes within the mill.
In experiments with small scale equipment, acidification of secondary
influent, followed by neutralization, was a successful treatment.
Coliform concentrations in the waste after secondary treatment were as
low as 1400 per 100 ml. The lowest value found for a control unit was
1.2 million per 100 ml.
9. Coliforms in secondary effluent from ammonia base sulfite processes
can be reduced to acceptable levels by approximately 5 ppm chlorine,
added as hypochlorous acid (HOC1) or sodium hypochlorite (NaOCl).
Molecular (gaseous) chlorine is not a suitable bacteriocide.
10. The most important factor which influences the activity of chlorine
against coliforms in Lebanon effluent is the pH of the chlorinating
solution. Chlorinating solutions with pHs of about 2 are relatively
ineffective. At higher pHs greater concentrations of total residual
chlorine are obtained without increasing the chlorine application rate.
This correlates with increased bactericidal activity.
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11. The effect of chlorinating solution pH on bactericidal activity
is related to one or more of the following reactions occurring near
the chlorine-effluent interface, before complete mixing:
a. Equilibrium reactions involving chlorine.
b. lonization of lignosulfonic acids and/or ammonia.
c. Formation of monochloramine (NH-Cl).
Low pH favors reactions between molecular chlorine and unionized
lignosulfonic acids which inactivate chlorine. At pH 7 and higher,
HOC1 and hypochlorite ions (OC1~) react more slowly with lignosulfonate
ions and the formation of NlUCl becomes possible. Complete mixing may
occur before active chlorine reacts with lignosulfonates.
12. Reaction rates between chlorine and effluent are related to the
concentrations of reactants. When the concentration of chlorine in a
chlorinating solution is increased the reaction rate with effluent
also is increased. When gaseous chlorine (C1-) is used there is an
interrelationship with pH which may make it especially difficult to
attain bactericidal chlorine residuals. With increasing levels of
chlorine, solutions become more acidic. This lowers the pH of larger
volumes of chlorine-effluent mixtures and reactions between Cl_ and
lignosulfonic acids become more complete before dilution can occur.
13. Sulfite (S03~) reacts rapidly with active chlorine. Approximately
30 percent of the "Biological Chlorine Demand" of Lebanon secondary
effluent was due to SCL . Concentrations of SO, in other wastes
were too high for adequate coliform kill with practical amounts of
chlorine.
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14. Full scale chlorination of secondary wastes from the ammonia base
sulfite pulping process can be improved by injecting sodium hydroxide
into the chlorinator's water supply. The amount required is that for
the neutralization of HC1 formed from chlorine hydrolysis Put another
way, it is the amount required to convert molecular chlorine to
hypochlorous acid. With this system coliforms were killed by 5 ppm
of applied chlorine. Without it, chlorine concentrations of 20 ppm
were often ineffective.
15. A chlorination system which responds to changes in effluent flow
would be more appropriate for the Lebanon operation. Variations in
effluent flow rates caused fluctuations in the concentrations of
applied chlorine because of a constant chlorine addition rate. Minor
fluctuations were due to batch processing. Major changes were caused
by variations in wind velocity and direction over the ponds.
16. Secondary effluent from both series and parallel operation can
be treated effectively with approximately 5 ppm chlorine. However,
when the mode of operation is changed from series to parallel, effective
treatment cannot be achieved with practical levels of chlorine for at
least several days. This is due to increased concentrations of sulfite
in the first pond in series.
17. In this study it was found that the concentrations of chlorine
required to accomplish the following correlated well with those
required to reduce coliforms to acceptable levels:
a. Stop bacterial motility within 30 minutes.
b. Inhibit oxygen uptake by secondary effluent by 64 percent or more.
c. Provide a total chlorine residual after a contact time of 5
minutes (5 minute residual).
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Three rapid methods for estimating chlorine activity were developed
using these criteria. They proved very useful in determining the
conditions required for effective chlorination and in monitoring full
scale chlorination.
18. Chlorination procedures which reduce coliforms to acceptable
concentrations do not produce effluents which would be toxic in
receiving waters. This conclusion was based on the following
observations:
a. Total chlorine residuals rarely persist for more than 2 hours in
secondary effluent. Passage time to receiving waters is 4 to 6 hours
b. The forms of chlorine which have a high degree of toxicity,
hypochlorous acid and the chloramines, are not detectable 5 minutes
after chlorination. Monochloramine added to secondary effluent to
provide 10 ppm chlorine reacts completely within 10 minutes.
c. Chlorinated effluent, aged for 2 hours, was not toxic to salmonoid
fingerlings when the waste was 20 times more concentrated than it
would be in receiving waters,
19. Continuous full scale chlorination had a beneficial effect on the
quality of receiving waters. Coliform concentrations in the South
Santiam River 3 miles and 8 miles downstream from the mill discharge
were reduced to the levels found upstream from the mill. Dissolved
oxygen in chlorinated effluent was not depleted during passage to the
river. This resulted in higher D.O. levels in the river particularly
at the confluence of the effluent and the river. By neutralizing
HC1 from chlorine hydrolysis, the caustic injection procedure minimized
pH changes which could affect receiving waters.
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20. The chlorination procedure for the Lebanon mill requires 113 Kg/day
(250#/day) of chlorine and 65 Kg/day (143#/day) of NaOH. Added to
secondary effluent with an average flow of 19.7 million I/day (5.2
million gal./day) this would provide concentrations of 5.7 ppm chlorine
and 3.3 ppm NaOH. At the time of writing chemical costs were 0.123 $/Kg
(0.056 $/lb) for chlorine and 0.060 $/Kg (0.0272 $/lb) for NaOH. The
daily cost for chemicals would be approximately $18. Of this total
22 percent was for NaOH.
21. The chlorination system described offers certain advantages.
Chlorine gas and sodium hydroxide can be purchased in concentrated
form and stored separately until needed. This avoids the high shipping
costs associated with dilute germicidal solutions such as sodium
hypochlorite. Since the two chemicals are not combined until a few
seconds before use there is no problem with loss in activity due to
storage. The procedure also provides a convenient means for comparing
chlorination and hypochlorination processes with relatively little
capital expense.
22. The modified chlorination system may have application for other
types of wastes. However, if the formation of NH2C1 is required for
its success, wastes which are deficient in ammonia nitrogen would
have to be supplemented with a source of ammonia ions.
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SECTION II
RECOMMENDATIONS
1. The modified chlorination processes may have application to wastes
other than those from sulfite mills and should be evaluated further.
The main feature of the method is to increase the pH of chlorinating
solutions before they contact the waste in order to reduce initial
reaction rates. In this study there was little opportunity to optimize
the process. Improvements might result from increasing the mixing
time of caustic and water and/or that between chlorine and diluted
caustic before the mixture reaches the waste to be treated. Ammonia
would be a less expensive neutralizing agent but was not effective in
this study perhaps because of inadequate retention time. These are
areas which merit further attention.
2. Lebanon secondary effluent contains over 100 ppm NHป which suggests
that chloramine formation may have contributed to the bactericidal
acitvity found in chlorinated effluent. Although no chloramines could
be detected within 5 minutes of chlorination, with normal amounts of
chlorine, the question was not resolved completely. It would be
pertinent to evaluate the bactericidal activity of C^, HOC1 and NaOCl
added to lignosulfonate containing wastes with and without ammonia.
Wastes from a sodium base or magnesium base sulfite process would be
appropriate starting materials.
3. Experiments with small aeration units showed that coliform concen-
trations in secondary effluent could be dramatically reduced by
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restricting their entry into the aeration units. This approach to
coliform control should be studied for full scale processes. Treatment
of coliform-containing wastes within the mill or changes in operating
procedures to minimize retention time and accumulations of sediments
are potential methods.
4. More information is needed on the reaction products of chlorine
with various wastes. This becomes increasingly important as regulations
require the disinfection of industrial effluents. Properties of interest
include the chemical nature of the compounds, their stability and
their toxicity to aquatic life. Attention should be given to the
various forms of chlorine. It is possible that for one type of waste
molecular chlorine would produce toxic addition products whereas
sodium hypochlorite would form oxidation products of low toxicity.
5. A system has been devised for varying the rate of chlorine and
caustic addition in response to changes in effluent flow. Optimum
conditions for chlorination should be established with the new apparatus.
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SECTION III
INTRODUCTION
Coliform bacteria, commonly known as coliforms, are present in large
numbers in the intestinal tracts of warm blooded animals. They can
be distinguished from other types of bacteria by their ability to
ferment the milk sugar lactose. These two characteristics were largely
responsible for establishing coliforms as indicators of human fecal
pollution. Currently, 29 states use total coliform populations as
an index of water quality and 24 of these, including Oregon, have a
standard of 1000 total coliforms per 100 ml for recreational waters.
High concentrations of coliforms in two Oregon rivers have been
2
associated with industrial effluents. The sanitary significance of
coliforms in industrial wastes is a debatable subject and outside the
scope of this study. Less controversial is the fact that a high
background level of coliforms from industrial wastes makes it difficult
to detect pollution from sources of known public health significance.
This was the type of situation encountered with the Crown Zellerbach
sulfite mill in Lebanon, Oregon. Coliform concentrations in secondary
effluent from this mill were consistently great enough to cause an
increase in coliforms in receiving waters, the South Santiam River,
to more than 1000 per 100 ml. This complicated sanitary surveys but
also provided the opportunity to determine the reasons for high
concentrations of coliforms in an industrial waste and to develop
methods for reducing their numbers to acceptable levels.
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SECTION IV
APPARATUS AND METHODS
ENUMERATION OF BACTERIA
Total Bacteria
The Standard Plate Count procedure described in Standard Methods for
3
the Examination of Water and Wastewater (Standard Methods) was used
except that plates were incubated at 20 to 25 C. for 4 to 6 days rather
than the conditions specified. Prior to plating, chlorinated samples
were treated with sodium thiosulfate to inactivate any residual chlorine.
Coliforms
3
Multiple Tube (MI) -- The Presumptive Test was used to enumerate total
coliforms. Five Lactose Broth (Difco) fermentation tubes were used for
each sample dilution tested. Concentrations of coliforms were computed
from Most Probable Number (MPN) tables.
Membrane Filter (MF) The Standard Total Coliform Membrane Filter
Procedure was used with m-Endo Broth-MF (Difco).
Chlorinated samples were treated with sodium thiosulfate before analyzing.
10
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MILL PRODUCTION AND WASTE TREATMENT
Production
The facilities at Lebanon, Oregon include an ammonia base sulfite mill
which produces unbleached paper products and lignosulfonate containing
by-products. The mill operates 3 batch digesters which produce 9 to
10 cooks every 24 hours,
Waste Treatment
Spent Sulfite Cooking Liquor -- Strong liquor is evaporated to a 40 to
50 percent solids concentration. It may be processed further in the
manufacture of by-products or burned if the supply exceeds the demand.
Weaker spent sulfite liquor is recycled while very dilute liquor goes
to primary treatment0
Primary Treatment -- Combined mill waste which includes paper machine
effluent, dilute spent sulfite liquor and by-product evaporator conden-
sate is pumped over a side hill screen for fiber recovery and into a
primary settling pond. Total liquid flow is approximately 17.4 million
I/day (4.6 MGD). Because of batch pulping and variations in by-product
manufacture, the volume and composition of the waste fluctuate. The
primary pond provides a retention time of 2 to 8 hours depending on the
accumulation of sediment. Periodically, the primary is pumped and the
solids are disposed of as landfill. During this operation which takes
4 to 5 days, unscreened, unsettled waste goes directly to the secondary
ponds. During the 6 to 8 hours required to refill the primary pond
there is no flow to the secondary units.
Secondary Treatment Wastes going to secondary treatment are supple-
mented with 1 to 1.5 ppm phosphorus and adjusted to pH 7 with ammonia,
when necessary. The two secondary ponds have a capacity of 64 million 1
(17 million gal.) each and provide a retention time of approximately
11
-------
7 days. During this study pond 1 contained six 25 hp aerators and one
75 hp aerator. Pond 2 was operated with two 75 hp units. Secondary
effluent is discharged into Mark Slough which flows into the South
Santiam River. Residence time in the slough is 4 to 6 hours. Dilution
of secondary effluent in the South Santiam River is in the range of
1:80 to 1:280 during periods of low flow.
Additional information on waste treatment has been given by Amberg,
et.,1.12
SMALL SCALE WASTE TREATMENT
Equipment
The function and capacities of components of the small waste treatment
system (Figure 12) are given in Table 11. Units 2 through 8 were
plastic containers purchased locally. Cork borers were used to make
the correct size holes for snug fits of tubing and stoppers which were
used to interconnect the units. The aeration stages, 9 and 10, were
plastic lined, 208 1 (55 gal.) metal drums. The contents of these units
were temperature controlled and completely mixed by recirculation through
the drums and through heating chambers fitted with 2000 watt, thermostat-
ically controlled, immersion heaters. Jabsco pumps connected to
adjustable Vickers drive units were used for recirculation. Aeration
was accomplished by aspirating air into the recirculation lines on the
vacuum sides of the pumps. A multichannel peristaltic metering pump
was used to dispense H_SO, and NaOH solutions and for pumping settled
influent to the aeration units.
Flow Sequence and Control
In the following description, numbers in parentheses refer to the units
shown in Figure 12. Neutralized influent from the mill manifold was
gravity fed through a 5.2 cm (2 in.) plastic line (1) to a. constant
12
-------
level headbox (2). Excess influent was sewered. Flow from the headbox
was adjusted to 1.5 1/min by rotating an adjustable delivery tube to
the correct angle. In this system the vertical distance between the
surface of the influent in the constant level headbox and that in the
delivery tubes represents the effective head. By rotating the tube the
effective head can be varied with a corresponding change in flow rate.
The waste basket (3) directed influent into the bottom of a 5.2 cm
plastic pipe which was installed in the first settling stage (4). This
reduced turbulence for more effective settling. The settled influent
flowed by gravity from the near top of unit 4 to the bottom of the
second settling stage (5).
The discharge from unit 5 was divided. A small amount, 32 ml/min was
pumped to the control aeration unit (10). The balance of 1.47 1/min was
gravity fed to a stainless steel T in the acidification unit (6). Five
percent H?SO, was pumped into another leg of the T at 28 ml/min. The
acid was carried in 0.32 cm (1/8 in.) tygon tubing which extended into
the influent stream to prevent direct contact between acid and the metal
T. Again, by gravity flow, acidified influent went to the bottom of a
retention stage (7) to increase the exposure time of bacteria to low
pH influent. From the near top of this stage the waste flowed to the
bottom of unit 8 where it was neutralized with 4.1 percent NaOH in the
same manner as described for acidification. Finally from the upper
section of unit 8 neutralized influent was pumped to the experimental
aeration drum (9) at the rate of 32 ml/min. The rest of the neutralized
influent was sewered.
Monitoring
Daily, or more frequently, pH measurements were made on waste in units
6 and 7 to determine if acidification was adequate. Checks also were
made on the equivalence of reagents. To do this both NaOH and H2SO^
reagents were pumped at normal rates for 1 minute into 1.51 of influent.
13
-------
If the pHs of influent before and after reagent addition were not the
same, appropriate adjustments were made of caustic flow rate.
Start Up Procedure
Unit 8, the neutralization stage, was filled with influent from the mill
manifold. The two aeration units, 9 and 10, were filled with unchlorinated
secondary effluent and connected to earlier stages via the peristaltic
pump (11). The system then was put into operation.
ANALYTICAL METHODS
Unless noted otherwise, procedures were those described in Standard
Methods.3
Total Residual Chlorine
To 100 ml sample volumes were added an excess of potassium iodide,
approximately 1 ml of 20 percent H.SO, and 1 to 2 ml of a 0.5 percent
starch solution. The blue starch-iodine complex was titrated to a
colorless end point with 0.025 N sodium thiosulfate. Preliminary tests
showed that acetic acid and HปSO, gave the same values for total residual
chlorine in effluent treated with sodium hypochlorite. Sulfuric acid
was used for future tests because its lower volatility made it less
objectionable to work with, especially in field studies.
Dissolved Oxygen
All dissolved oxygen measurements were made with a Yellow Springs
Instrument Co. (YSI) Model 54 Oxygen Meter. Oxygen uptake studies were
made using Model 5420 self-stirring BOD Bottle Probe. All other
measurements were made with a standard probe.
14
-------
SAMPLING
All samples were grab samples which were analyzed within 2 hours. Those
for bacteriological analyses were collected in sterile, plastic Whirl-
Pak (Nasco) bags.
FISH TOXICITY STUDIES
Apparatus (Figures 46 and 47)
The aging box, headboxes and fish channels were 1.9 cm (3/4 in.) plywood
painted with 3 coats of Fish Hatchery White paint. The fish channels
12
and water headbox had been used in previous studies. The aging box
channels were 28.7 cm wide and 81.3 cm high (11.3 in. x 32 in.). This
tall, narrow configuration suggested that uneven heating or other
factors might cause large variations in flow rates between upper and
lower portions of effluent. To evaluate this the box was first filled
with water. Water was then continuously pumped into the mixing funnel
at the same rate as planned for effluent. Enough brom cresol green dye
was added to provide a distinct pattern. During passage through the
channels a wedge shaped pattern was formed with the bottom leading the
top by 15 minutes after 2 hours. Temperature readings taken with a
submersible probe showed the lower portions of effluent to be 0.2 to
0.3ฐ C. colder than upper portions.
Flow Sequence and Control
Prior to full scale chlorination, secondary effluent was pumped to the
mixing funnel at the rate of 26.5 1/min (7 gal./min). A sodium hypo-
chlorite stock solution containing 10,000 ppm active chlorine was added
to the effluent at the rate of 26.5 ml/min to provide an initial chlorine
concentration of 10 ppm. Chlorine flow rate was controlled with an
adjustable delivery tube as described for the small scale system. The
solution was added from a Mariotte box. This was a closed container,
fitted with an air inlet tube which extended into the chlorinating
15
-------
solution. The effective head for flow regulation was the vertical
distance between the bottom of the air inlet tube and the tip of the
delivery tube. This made it possible to use most of the chlorinating
solution without changing the effective head pressure. When full scale
mill chlorination was started, mill chlorinated effluent was pumped to
the funnel.
From the Mix Box chlorinated effluent flowed by gravity to the Effluent
Delivery Box. Excess flows were used to provide a constant head at this
stage. Flow to the Aging Box was regulated by adjusting three delivery
tubes. Depending on the retention time desired, a pump was positioned
in the Aging Box and aged effluent was pumped to the Effluent Head Box
at an excess rate to provide a constant head. Flow of chlorinated
effluent to the channels was controlled with adjustable delivery tubes.
To obtain controls, unchlorinated effluent was pumped at the desired
rate to the top of the mixing flume of one of the fish channels. Desired
flow rates of dilution water to the channels were obtained by adjusting
v-notch weirs in the Water Head Box.
Handling of Fish
Steelhead trout (Salmo gairdneri) and Sockeye salmon (Oncorhynchus nerka)
fingerlings were obtained from the Fish Toxicological Station of the
Environmental Protection Agency in Corvallis, Oregon. They were trans-
ported to the test site in oxygenated carboys. The fish were maintained
in a channel with flowing water for at least 5 days. The required
numbers were then transferred to test channels which contained water
flowing at the standardized rate of 0.63 I/sec (10 gal./min). At this
stage the Effluent Head Box contained only water which was being added
to the channels at rates equivalent to those to be used for chlorinated
effluent. After an additional 3 days for acclimatization, water flow
to the Effluent Head Box was replaced by an equivalent flow of chlorinated
and aged effluent.
16
-------
SECTION V
EVALUATION OF METHODS FOR ENUMERATING COLIFORMS
COMPARISON OF MF AND MT TESTS
3
The current edition of Standard Methods recognizes two standard
procedures for enumerating coliforms. They are the Membrane Filter (MF)
procedure, and the use of Multiple Fermentation Tubes (MT) to determine
the most probable numbers. These two techniques were used to determine
coliform concentrations in various mill wastes.
For 10 out of 14 samples of unchlorinated wastes the MT procedure
yielded higher results (Table 1). However, on the basis of 1ฐ810 of
coliform concentrations, differences were minor (Figure 1) with maximum
variations being approximately 0.5 log,Q unit. Because of the enormous
numbers required to express bacterial populations and differences in
concentrations, it is common practice to express them in log units.
The MT procedure also gave higher coliform counts for 25 out of 32
samples of chlorinated secondary effluent (Table 2). However, when
the Iog1n of coliforms were plotted against chlorine concentrations or
reaction times (Figures 2-5), similar death curves were obtained using
data obtained by the two procedures.
For the following reasons the MF procedure was used to enumerate
coliforms in most of the subsequent studies:
17
-------
Table 1, COMPARISON OF MEMBRANE FILTER AND MULTIPLE TUBE METHODS FOR ENUMERATING
COLIFORMS IN UNCHLOIUNATED MILL WASTES
Description of samples
Date
9/16/71
9/22/71
9/23/71
9/24/71
9/28/71
9/28/71
9/28/71
9/29/71
10/26/71
10/27/71
3/16/72
3/17/72
4/4/72
4/12/72
Source
Primary influent
Secondary effluent
Secondary effluent
Secondary effluent
Secondary effluent
Main sever before
evaporator
Main sewer water
leg after
evaporator
Secondary effluent
Secondary effluent
Secondary effluent
Secondary effluent
Secondary effluent
Secondary effluent
Secondary effluent
PH
3.80
6.70
6.90
__
7.05
9.15
8.65
7.15
7.20
7.30
7.20
7.20
6.90
7.45
Coliform bacteria
Cells/100 ml
Membrane
filter
39 X 10*
31 X 105
48 X 10^
53 X 10^
33 X 10
17 X 104
60 X 104
c
49 X 10^
320 X 10^
240 X 10;?
200 X 105
250 X 10^
130 X 105
90 X 105
Multiple
tube
49 X 102
70 X 10J>
79 X 10^
54 X 105
46 X 10^
23 X 104
A
49 X 10*
p*
170 X 10^
350 X 105
130 X 10^
140 X 105
130 X 10^
160 X 10ฐ
350 X 105
Login cells/100 ml
Membrane
filter
3.59
6.49
6.68
6.72
6.52
5.23
5.78
6.69
7.51
7.38
7.30
7.40
8.11
7.95
Multiple
tube
3.69
6.85
6.90
6.73
6.66
5.36
5.69
7.23
7.54
7.11
7.15
7.11
8.21
7.54
Diff.
between
methods,
%
23
77
49
2
33
30
20
110
9
59
35
63
21
118
Method
giving
highest
count
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M
SECONDARY EFFLUENT
IMBRANE FILTER
MULTIPLE TUBE
PRIM.
INF.
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1
SEPTEMBER
1971
-MARCH APRIL
1972"
SAMPLE DATE
Figure I. Comparison of methods for enumerating conforms in unchlorinated mill wastes.
-------
Table 2. COMPARISON OF MEMBRANE FILTER AND MULTIPLE TUBE METHODS FOR ENUMERATING
COLIFORMS IN CHLORINATED SECONDARY EFFLUENT
Date
(1971)
9/22
9/24
9/28
9/28
9/29
9/29
9/29
9/29
10/26
10/26
10/26
10/26
10/26
10/26
10/26
10/26
10/26
CL
cone. ,
ppm
1.0
2.3
7.0
7.0
5.3
7.0
8.9
10.8
9.1
9.1
9.1
9.1
9.1
9.1
9.1
9.1
9.1
Reaction
time
10 Mins.
10 Mins.
10 Mins.
20 Mins.
10 Mins.
10 Mins.
10 Mins.
10 Mins.
1 Min.
5 Mins.
10 Mins.
20 Mins.
40 Mins.
80 Mins.
160 Mins.
320 Mins.
24 Hours
Method
of chlorine
application
Cl2-Mill
Cl2-Mill
Cl -Mill
Cl2-Mill
Cl2-Mill
CL2-Mill
Cl2-Mill
Clr-Mill
Cl2-Mill
Cl -Mill
Cl2-Mill
Cl2-Mill
Cl2-Mill
Cl2-Mill
Cl2-Mill
Cl2-Mill
Cl2-Mill
Coliform bacteria
Cells/100 ml
Membrane
filter
29 X 10*
51 X 102
29 X 10
4 X 102
21 X 105
74 X 10.*
81 X 103
1 X 10?
22 X 10/
39 X 10
12 X 10*
32 X 10;
37 X 10;
8 X 10^
11 X 10
61 X 10}
63 X 101
Multiple
tube
49 X 10^
54 X 105
80 X 10*
20 X 10^
54 X 10~
350 X 10^
920 X 10,
35 X 10*
1300 x lor;
170 X 10
92 X 10^
79 X 10^
350 X 10^
18 x 10;
17 x 10;
28 X 101
5
Logjp eel
Membrane
filter
6.46
6.71
3.46
2.60
6.32
5.87
4.91
2.00
6.34
5.59
5.08
4.51
3.57
2.90
3.04
2.79
2.80
Is/100 ml
Multiple
tube
6.69
6.73
3.66
3.30
6.51
6.54
5.96
3.54
8.11
6.75
5.71
4.65
4.54
3.26
3.48
2.45
0.70
Diff.
between
methods,
%
51
6
94
133
88
130
168
189
193
125
154
85
162
77
43
74
197
Method
giving
highest
count
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Table 2 (continued).
COMPARISON OF MEMBRANE FILTER AND MULTIPLE TUBE METHODS FOR ENUMERATING
COLIFORMS IN CHLORINATED SECONDARY EFFLUENT
Date
(1972)
3/16
3/17
4/12
Cl
cone . ,
ppm
8.0
10.0
10.0
12.5
12.8
20.5
26.0
4.0
6.0
8.0
10.0
21.2
22.2
10.0
10.0
Reaction
time
30 Mins.
30 Mins.
30 Mins.
30 Mins.
30 Mins.
30 Mins.
30 Mins.
30 Mins.
30 Mins.
30 Mins.
30 Mins.
30 Mins.
30 Mins.
6 Mins.
30 Mins.
Method
of chlorine
application
NaOCl-Lab
NaOCl-Lab
Cl2-Mill
Cl.-Mill
Clj-Mill
Cl7-Mill
NaOCl-Lab
NaOCl-Lab
NaOCl-Lab
NaOCl-Lab
Cl9-Mill
Cl7-Mill
NaOCl-Lab
NaOCl-Lab
Colifovm bacteria
Cells
Membrane
filter
9 X 10*
38 x 10!:
10 X 10^
6 X 10b
9 X 10J?
3 X 10,
37 x 10;
40 X 10^
5 X 103
3 X 107
5 X 10^
30 X 10^
77 X 10.
*. 10*
1 X 10
'100 ml
Multiple
tube
14 X 10*
21 X 10^
8 X 10*?
9 X 10ฐ
5 X 106
54 X 10ฃ
17 X 10.
30 X 10^
2 X 10;
17 X 10*
2 X 103
8 X 10^
170 x io:J
79 X 10^
13 X 102
Log10 cells/100 ml
Membrane
filter
2.96
3.58
7.00
6.78
6.96
6.48
3.57
4.60
3.70
4.48
4.70
6.48
5.89
<:2.00
2.00
Multiple
tube
3.15
3.32
6.90
6.96
6.70
7.73
5.23
4.48
3.30
5.23
3.30
5.90
6.23
4.90
3.11
Diff.
between
methods,
%
43
58
22
40
57
179
191
29
86
140
185
116
75
199
171
Method
giving
highest
count
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6-
2-
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CONTACT TIME: 2min
A
O
MULT I RLE TUBE
MEMBRANE FILTER
468
CHLORINE, ppm
10
Figure 2. Comparison of methods for enumerating coliforms in chlorinated effluent.
Mill trial of September 29, 1971
-------
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on
o
4-
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o
2-
Cl CONC. 9.1 ppm
0
10
20
A
0
MULTIPLE TUBE
MEMBRANE FILTER
30 40 ' ' 80
CONTACT TIME, minutes
160
320
Figure 3. Comparison of methods for enumerating coliforms in chlorinated effluent.
Mill trial of October 26, 1971.
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8
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6-
2-
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LABORATORY
CHLORINATION
A MULT I RLE TUBE
o MEMBRANE FILTER
CONTACT TIME: 30 min.
MILL CHLORINATION
1 I T
5
-| 1 1 r-
10 15 20
CHLORINE, ppm
T
25
30
Figure 4. Comparison of methods for enumerating conforms in chlorinated effluent.
Laboratory and mill trials of .March 16, 1972.
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LABORATORY
CHLORINATION
MILLCHLORINATION
MULTIPLE TUBE
MEMBRANE FILTER
CONTACT TIME: 30 min.
15
CHLORINE, ppm
nr
20
25
30
Figure 5. Comparison of methods for enumerating coliforms in chlorinated effluent.
Laboratory and mill trials of March 17, 1972.
-------
The MF method is better suited for the daily analysis of a large number
of samples.
The MF method provides a definite number for bacterial concentrations
so is appropriate for studying the effect of variables on bacterial
populations. In contrast, the MT procedure indicates a range of
concentrations. At the 95 percent confidence limits, the difference
between upper and lower values may exceed one order of magnitude.
In these preliminary tests the two methods gave comparable results.
Conclusions concerning the order of magnitude of coliforms in various
wastes or the effects of chlorination on coliforms would have been
similar with data from either method.
The possibility was considered that coliforms exposed to chlorine or
other adverse conditions might have a better chance for survival in
lactose fermentation broth than they would on a membrane filter saturated
with m-Endo Broth-mf. The latter medium which is used in the MF test
contains surface active agents, ethanol and other compounds which
might be inhibitory to coliforms in a weakened condition. For this
reason, occasional analyses were made using the MT Presumptive test as
well as the MF procedure.
REPRODUCIBILITY OF RESULTS
Reproducibility of the MF method was found to be good. Differences
between duplicates averaged 17 percent for 30 samples of various types
of wastes (Table 3). The greatest difference for a single sample was
122 percent or 0.62 log1Q unit (Figure 6).
26
-------
BARS IN SEQUENCE SHOW RESULTS FOR SAMPLE A, B, AND AVERAGE.
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L- 1 1 1 r~ i
14 15 16 16 17 18 14 15 16 16 17 18 14 15 16
DATE (SEPTEMBER 1971)
PRIM. INF. PRIM. EFF. SEC. EFF.
SOURCE OF SAMPLES
Figure 6. Reproducibility of conform counts using the membrane filter method.
-------
Table 3. REPRODUCIBILITY OF THE MEMBRANE FILTER METHOD FOR ENUMERATING COLIFORMS
Date
(1971)
9/14
S 9/15
Sample
1 Prim infl
2 Prim infl, neut
3 Prim eff
4 Prim eff, neut
5 Secondary infl
6 Secondary eff
1 Prim infl
2 Prim infl, neut
3 Prim eff
4 Prim eff, neut
5 Secondary infl
6 Secondary eff
PH
9.0
7.0
8.8
7.0
8.7
6.8
8.9
7.1
8.8
7.0
8.6
6.8
Coliforms/100 ml J
A
102 X 10 J
30 X 10,
38 X 10;
33 X 104
40 X 104
24 X 10|
127 X Iff*
131 X 104
40 X 10?.
74 X 10,
24 X 104
32 X 105
B
130 X 104
30 X 104
38 X 104
8 X 104
46 X 104
20 X 10?
114 X 10*;
110 X 104
40 X 10
82 X 10,
30 X 104
34 X 105
Ave.
116 X lof
30 X 104
38 X 104
20.5 X 104
43 X 104
22 X 10;
120 X 10*:
121 X 104
40 X 104
78 X 1
-------
Table 3 (continued). REPRODUCIBILITY OF THE MEMBRANE FILTER METHOD FOR ENUMERATING COLIFORMS
Date
(1971)
9/16
9/16
9/17
9/18
Mean
Samp le
1 Prim infl
2 Prim infl, neut
3 Prim eff
4 Prim eff, neut
5 Secondary infl
6 Secondary eff
7 Prim infl
8 Prim infl, neut
9 Prim eff
10 Prim eff, neut
7 Prim infl
8 Prim infl, neut
9 Prim eff
10 Prim eff, neut
7 Prim infl
8 Prim infl, neut
9 Prim eff
10 Prim eff, neut
"* "
PH
8.6
7.1
8.6
7.0
8.4
7.0
3.8
7.0
4.0
7.0
3.8
7.2
4.1
7.1
3.8
7.2
4.1
7.1
_-
Coliforms /100 ml
A
64 X 10*
18 X 1(T
76 X 104
84 X 10
26 X 10\
34 X 10,
40 X 1CT
22 X 103
71 X 102
35 X 103
^100 .
84 X 1CT
^100
80 X 10*
<100
41 X 103
35 X 105
31 X 10,
38 X 10*
19 X 103
63 X 10*
31 X 10
100
98 X 10*
100 .
85 X 10
r^100 .
50 X 10
<100
17 X 10J
~~
Ave .
60.5 X 104
16.5 X 105
79 X 10*
76.5 X loi
30.5 X 10
32.5 X 10;
39 X 1(T
20.5 X 103
67 X 102
33 X 103
cioo
91 X 10*
<100
82.5 X 10
clOO
45.5 X 10J
-100
18.5 X 10J
" *
Log1n Colif/100 ml
AIU
5.81
6.25
5.88
6.92
6.42
6.53
3.60
4.34
3.85
4.54
0.07
0.03
0.09
0.07
0.08
vo
8 -- Unable to calculate
-------
EXPERIMENTAL POUR PLATE PROCEDURE
A pour plate procedure using WL Nutrient Medium (WLN) (Difco) was
evaluated for enumerating coliforms. This medium, with a yeast
inhibitor added, is formulated to detect bacterial contaminants in
4
various fermentation processes. It contains brom cresol green as an
indicator of acid production. Since coliforms are acid producers the
possibility was investigated that they could be distinguished and
enumerated according to this ability.
It was found that acid was produced by bacteria from secondary effluent
but its diffusion into the agar made it impossible to identify acid
producing colonies. However, results based on total colony counts
were encouraging. The mean ratio of total counts on WLN medium to
coliforms as determined by the MF method, was 1.5:1 for 9 samples
(Table 4). Extreme ratios ranged from 1.0:1 to 2.3:1. Of 41 colonies
transferred from WLN plates to lactose broth fermentation tubes,
68 percent produced gas. This is the positive presumptive test for
coliform bacteria. The mean total plate count made on WLN was only
2.6 percent of the mean total plate count obtained using Tryptone
Glucose Extract Agar, TGE (Difco). The latter is a standard plate
4
count medium used in the dairy industry.
The results showed that the WLN plating medium, applied to Lebanon
mill waste, was highly selective in enumerating only small percentages
of total bacterial populations. Most bacteria recovered were coliforms
but significant numbers of other types also grew on the plates. When
considered in terms of orders of magnitude or login ฐf populations
(Figure 7), the correlation between MF counts of coliforms and WLN
total counts appears to be good.
The selective action of WL Nutrient medium was probably due to its
high sugar concentration of 50 g/1 and relatively low pH of 5.5.
30
-------
Table 4. EVALUATION OF A PLATE COUNT PROCEDURE USING WL NUTRIENT MEDIUM
FOR ENUMERATING COLIFORMS
Sample
description
Inf to primary
Inf to secondary
Sec effluent
Sec effluent
Sec effluent
Sec effluent
Sec effluent
Chlorinated ( 2.7)
secondary ( 4.5)
effluent (10.6)
(Cl, ppm) (15.0)
(10.0)
Mean
Date
(1971)
12/30
12/30
12/8
12/16
12/23
12/27
12/30
12/23
12/23
12/23
12/23
12/27
mm ซ
Bacteria/100 ml
Total count
TGE
21 X IO6
32 X IO6
11 X IO*
83 X 10ฐ
35 x 10;
89 X 10
29 X 10b
31 X IO7
39 X IO7
20 X IO6
ID?
50 X 10J
--
WL nut.
39 X IO4
16 X IO5
46 X 10"!
12 X 10ฐ
10 X 10^
74 X 10^
28 X 10
80 X 10
72 x 10;
io4
IO2
2 X IO2
__
Colif
MF
33 X IO4
83 X IO4
40 X IO5
52 X 10^
10 X W
54 X 10
16 X IO5
51 X 10^
58 X IO5
- io4
: . 10
-.-'. IO2
--
WL nut
count:
colif
count
1.2
1.9
1.2
2.3
1.0
1.4
1.8
1.6
1.2
_.
--
--
1.5
% of TGE
total count
WL
nut.
1.9
5.0
0.04
0.14
2.9
8.3
1.0
2.6
1.8
-.
--
--
2.6
Colif
MF
1.6
2.6
0.04
0.06
2.9
6.1
0.06
1.6
1.5
--
--
--
1.8
Lactose ferm
by colonies
from WL nut. med
# Tested
3
8
5
__a
5
__
10
5
5
--
--
--
41
(Total)
% Pos
33
62
100
--
60
--
70
60
80
_.
--
--
68
a -- Not done.
-------
10-
8-
TOTAL PLATE COUNT WITH TRYPTONE GLUCOSE EXTRACT AGAR
TOTAL PLATE COUNT WITH W. L NUTRIENT MEDIUM
TOTAL COLIFORMS WITH MEMBRANE FILTER METHOD
LU
h
-------
The usual environment in the Lebanon secondary ponds includes a pH of
approximately 7 and a sugar concentration of less than 100 mg/1.
Bacteria adapted to these conditions would find growth conditions
hostile on WLN. These considerations suggest the possibility that
coliforms are not indigenous to the secondary ponds.
A plate count method for enumerating coliforms would be much more
rapid than the standard procedures. This saving in time becomes
important as the number of required analyses increases. It is possible
that the WL Nutrient Medium could be made more specific for coliforms
by substituting lactose for glucose and by incubating plates at 35 C.
rather than at 20-25 C. as was done in this study.
33
-------
SECTION VI
BACTERIA IN AERATED STABILIZATION BASINS
CONCENTRATIONS
Coliform concentrations in secondary effluent ranged from 300 thousand
to 150 million per 100 ml during parallel operations of the ponds
(Table 5).
Table 5. CHARACTERISTICS OF SECONDARY COMPOSITE EFFLUENT
DURING PARALLEL OPERATION. SUMMARY OF DATA.
Measurement
PH
Temp, ฐC.
SO-j, ppm
BOD, ppm
Total bact/100 ml
X 107
Coliforms/100 ml
X 105
Coliforms, % of
total bacteria
No. of
analyses
104
93
22
107
82
107
82
Mean
7.1
23.5
3.6
106
284
251
1.9
S.D.a
0.5
4.9
0.6
25
256
291
2.2
Var,
%
__b
21
17
24
90
116
116
Range
5.4-7.4
12.0-32.4
2.8-4.9
72-192
9-1000
3-1500
0.01-16.5
S.D. - Standard Deviation.
b -- Not calculated.
34
-------
The mean of 107 analyses made over a 15 month period was 25 million
per 100 ml with a standard deviation of 29 million per 100 ml. This
variation in counts was studied in more detail by comparing results
obtained for samples collected during a single day with those obtained
for samples collected on different days and during different months.
The variation among hourly samples was 19 percent as compared with
86 percent and 93 percent for daily and monthly samples, respectively
(Table 6). This indicates that the coliform population was responding
to changes in conditions and that the variations found were not due
to sampling or analytical problems.
Although coliform concentrations in secondary effluent seldom were
less than one million per 100 ml, they represented only a small segment
of the total bacterial population. On the basis of mean viable counts
for a 15 month period (Table 5), coliform concentrations were less
than two percent of total bacterial concentrations. Individual values
are given in Table I in the Appendix.
During the 15 month interval the total viable bacterial population
averaged 2.8 billion cells per 100 ml (Table 5) and varied less than
did the coliforms. Microscopic counts made on preserved samples
indicated higher bacterial concentrations, ranging from 6.2 to 42
billion per 100 ml (Table 7). The difference between viable and
microscopic counts could be due to a combination of the following:
The microscopic methods did not distinguish between live and dead cells,
It is possible that a large percentage of the cells counted were dead.
Plating conditions were not appropriate for a large segment of the
bacterial population. For example, the medium used was probably too
rich in nutrients and the incubation time too short to support growth
of prosthecate bacteria which were present in significant numbers
(Table 7).
35
-------
Table 6. VARIATIONS IN BACTERIA IN SECONDARY EFFLUENT
DURING PARALLEL POND OPERATION
Month
Dec. (1971)
Hourly values
Daily values
March (1972)
Hourly values
Daily values
May (1972)
Hourly values
Daily values
June (1972)
Hourly values
Daily values
July (1972)
Hourly values
Daily values
Dec. 13, 1971 to
July 31. 1972
Hourly values
Daily values
Monthly values
Day(s)
31
31
13-31
13
14
15
16
24
13-24
13-24
18
18
18,25
13
13
8-30
6
7
8
11
6-11
5-31
Total bacteria
# of
values
__a
--
2
4
3
2
3
14
8
3
3
1
2
2
8
2
2
3
21
19
4
X lO'/lOO ml
Mean
--
67
66
173
145
71
110
550
550
410
504
480
* ป
427
398
S.D.
13
28
55
7.1
22
46
115
::
71
247
28
61
198
Var.,
%
--
19
73
32
5
31
38
42
21
21
17
17
49
6
6
14
31
41
50
Col i forms
# of
values
2
2
7
2
6
3
2
3
16
8
3
3
2
2
2
11
2
2
3
2
9
12
32
40
5
X 1CP
Mean
21.5
36.8
115
220
123
195
417
215
840
695
100
217
51
21
23
111
175
268
7100 ml
S.D.
4.9
33
35
58
21
7.1
68
127
147
205
28
126
1.4
7.1
1.2
30
240
250
Var.,
Z
23
23
90
30
26
17
4
16
20
59
18
18
29
28
28
58
3
34
5
27
16
137
19
86
93
a -- Not done or calculated,
-------
Table 7. DIFFERENTIAL MICROSCOPIC COUNTS OF SECONDARY INFLUENT AND EFFLUENT
(Courtesy of Drs. E. J. Ordal and J. T. Staley. Univ. of Wash.)
Analysis
Total microscopic
count, cells per
100 ml X 107
Differential count,
percent of total count
Rods
Prosthecomicrobium
Anc alomicrob ium
Hyp homicrobium
Caulobacter I
Caulobacter II
Spirillum, thin
Spirillum, fat
Actinomycetes
Vibrios, large
Vibrios, small
Cocci
Bent rods
Spirochaetes
Unclassified
aNot done.
November 30
Inf.
99
98
- 1
1.0
1
1
1
1.0
xl
1
1
1
1
I
1
1
Pond 1
620
47
9.3
21
1
1.8
.1
4.6
1.4
15
1
*' 1
1
- 1
1
.- 1
1971
Pond 2
675
65
1.0
14
7.9
5.9
1
4.3
0.6
1.4
- 1
1
1
1
1
1
March 9, 1972
Inf.
a
87
.1
-'.1
1
^ 1
.1
11
1
2.0
1
1
:i
i
1
i
Pond 1
590
9.5
1
32
18
12
6.0
17
3.1
1
1
1
1
1
1
2.4
Pond 2
800
6.6
2.9
40
15
11
5.1
2.9
15
1
1
1
.:i
i
i
1.5
November 2. 1972
Inf.
0.03
92
1
:l
1
1
.; i
4
1
1
:i
4
1
1
j' j
<'. 1
Pond 1
4200
44
< I
4.0
1
1.0
. 1
3.0
2f\
.0
ซ f\
10
4.0
12
9.0
8.0
2/\
.0
Pond 2
3500
42
2.0
5.0
- 1
6**
.0
... 1
c'.l
5f\
.0
1f\
.0
% 1-
15
8.0
5.0
2.0
7.0
2f\
U
-------
Microscopic counts of March 9 substantiate the conclusion, based on
viable counts, that coliforms represent only a small fraction of the
total bacterial population in secondary treatment ponds. On this date
less than 10 percent of the total bacteria were rod-shaped and it is
probable that only a small portion of these were coliforms. No
conclusions can be drawn on microscopic counts of other days. Rod-
shaped bacteria represented a major segment of total bacteria but
coliforms could not be distinguished microscopically.
TYPES
Routine microscopic observations showed that the secondary ponds were
inhabitated by significant numbers of bacteria with unusual shapes.
They were called to the attention of E. J. Ordal and J. T. Staley
(University of Washington) who recognized them as prosthecate bacteria.
The term prostheca refers to rigid cellular appendages. Staley
discovered two types of prothecate bacteria in fresh water and proposed
the new genera classification Ancalomicrobium and Prosthecomicrobium.
He has observed these bacteria as well as members of the genera
Caulobacter and Hyphqmicrobiurn in Lebanon secondary effluent (Figure 8,
Table 7). All strains of prosthecate bacteria studied by Staley5
required vitamins and grew rather slowly in media with low concentra-
tions of carbohydrates. Other studies suggest that the appendages of
prosthecate bacteria reduce the rate of settling or function to
increase surface membrane area to allow the bacteria to grow in
environments which are low in nutrients. Prosthecate bacteria obviously
multiplied in the secondary ponds (Table 7) but the role of this
interesting group of organisms in secondary treatment was not determined.
Their presence may be an indication that concentrations of soluble
carbohydrates have been reduced to relatively low levels.
38
-------
HYPHOM1CROBIUM
CAULOBACTER
PROSTHECOMICROBIUM
ANCALOMICROBIUM
Figure 8. Prosthecate bacteria in Lebanon secondary effluent.
"Courtesy of Dr. J. T. Staley, Univ. of Washington. "
Approximate magnification 4000x.
39
-------
Several other morphological types of bacteria were observed in
secondary effluent (Table 7, Figure 9). Routine microscopic observations
showed that concentrations of motile bacteria, especially spirilla,
were frequently inversely related to concentrations of protozoa.
40
-------
FROM CZ LARGE AERATED PONDS
FROM EPA UNIT
Figure 9. Bacteria in secondary effluent.
Approximate magnification 1600x.
41
-------
SECTION VII
EFFECT OF VARIABLES ON CONCENTRATIONS OF BACTERIA
IN SECONDARY EFFLUENT
INOCULATION
Aerated Basins
Effluent from the primary settling pond is the immediate source of
bacteria for the aerated secondary basins. Primary effluent is
equivalent to secondary influent except that the latter has been
supplemented with H^PO, and neutralized with ammonia when necessary.
The mean coliform concentration of 86 secondary influent samples
analyzed over a 15 month period was 77 million per 100 ml (Table 8).
Table 8. CHARACTERISTICS OF SECONDARY INFLUENT.
SUMMARY OF DATA.
Measurement
PHS
Temp , C .
SO-, ppm
BOD, ppm
Total bact/100 ml
X 10
Coliforms/100 ml
X 10
Col i forms, % of
total bacteria
No. of
analyses
58
78
30
86
68
86
68
Mean
6.9
34.2
142
413
44
773
19
S.D.
2.1
4.3
72
57
152
1630
22
Var,
_.b
13
51
14
345
211
116
Range
3.2-10
25.5-46
71-322
240-560
0.2-980
0.02-11,000
0.001-100
Before neutralization.
bNot calculated.
42
-------
This was three times greater than the mean found for secondary effluent
samples during a similar period (Table 5). Complete data for influent
samples are given in Table II in the Appendix.
Inoculation by primary effluent must be considered as a major influence
on coliform levels in secondary ponds.
Variations in bacterial concentrations, especially coliforms, in
secondary influent (Figure 10) were much greater than found for
secondary effluent (Figure 11). Possible reasons for this will be
discussed in the sections dealing with the effect of pH on coliform
concentrations. As with secondary effluent, coliform variation was
greater among daily samples than among hourly samples (Table 9).
Over longer periods of time the factors influencing counts tended to
equalize. Variations over monthly intervals approached those found
for hourly samples.
The following comparisons suggest the interesting possibility that
coliforms are proliferating in the primary pond or within the mill and
that their presence in secondary effluent is the result of continual
inoculation:
The total bacterial population increases during secondary treatment
whereas coliforms decrease (Table 10).
In secondary effluent coliforms represent less than 2 percent of the
total bacteria (Table 5) compared to 19 percent for the daily mean of
influent samples (Table 8). Individual values exceeding 40 percent
were not unusual for influent and in two samples the entire population
seemed to be coliforms.
43
-------
10,
8
on
LU
GO
O
o"
O
6 -
4
2 -H
1 COLIFORM BACTERIA
1
TOTAL BACTERIA
1971
Figure 10. Concentrations of bacteria in secondary influent during parallel operation.
-------
T
CONFORM BACTERIA
QTOTAL BACTERIA
o
0
1971 1972
Figure 11. Concentrations of bacteria in secondary effluent during parallel operation.
-------
Table 9. VARIATIONS IN BACTERIA IN SECONDARY INFLUENT
DURING PARALLEL POND OPERATION
Month
March (1972)
Hourly values
Daily values
4> June (1972)
ฐ" Hourly values
Daily values
July (1972)
Hourly values
Daily values
Sept. (1972)
Hourly values
Daily values
March 13 to
Sept. 29, 1972
Hourly values
Daily values
Monthly values
Day(s)
13
14
15
16
24
13-24
13-24
13
13
8-28
8
8
8-31
15
15
15-29
Total bacteria
# of
values
2
4
3
__a
3
12
8
2
2
8
0
0
0
2
2
8
16
24
3
X lO'/lOO ml
Mean
4.0
3.8
3.0
_.
139
-_
29
9.5
-_
26
__
__
--
66
__
28
._
--
28
S.D.
3.2
2.2
1.0
__
80
_-
52
0.71
37
~
__
--
76
__
35
--
1.6
Var.,
%
80
58
33
__
58
55
179
7.5
7.5
142
__
-_
115
115
125
57
149
5.7
Col^forms
# of
values
2
6
3
2
3
16
8
2
2
8
2
2
7
2
2
8
22
31
4
X 10-7100 ml
Mean
85
86
65
24
2490
--
518
175
--
272
260
.-
1490
1450
338
--
--
654
S.D.
106
59
84
21
2030
--
922
163
__
439
255
1560
71
_.
479
~
--
567
Var.,
%
125
69
130
88
82
92
178
93
93
161
98
98
105
4.9
4.9
142
85
148
87
a-~ Not done or calculated.
-------
Table 10. EFFECT OF SECONDARY TREATMENT ON CONCENTRATIONS OF BACTERIA
Date
September, 1971
December, 1971
March, 1972
April, 1972
June, 1972
July, 1972
August, 1972
September, 1972
October, 1972
November^ 1972
Mean
Total ba
Cells/100 ml X 107
Influent
70
9
29
0.3
26
a
16
28
61
140
42
Effluent
197
132
110
104
503
--
564
130
312
720
308
pteria
Ratio
Effluent: influent
2.8
14.7
3.8
347.0
19.3
.
35.2
4.6
5.1
5.1
7.3
Col i forms
Cells/100 ml X 105
Influent
4
20
518
1
272
1490
953
338
1580
873
605
Effluent
39
37
215
533
217
175
335
240
483
317
259
Ratio
Effluent: influent
9.8
1.8
0.4
533
0.8
0.1
0.4
0.7
0.3
0.4
0.4
a -- Not determined.
-------
An increase in coliforms in effluent during the period from December
through March (Figure 10) reflected a similar increase in influent
samples (Figure 11).
These data are suggestive, however, other considerations prevent the
drawing of definite conclusions:
Waste treatment is continuous and the grab samples analyzed represent
only a very small fraction of the total waste.
In spite of wide fluctuations in coliforms in secondary influent
(Figure 10), populations remain relatively stable in effluent (Figure
11) and do not always reflect changes in influent concentrations.
The finding that coliforms represent only a small percentage of the
total number of bacteria in secondary ponds may be related to the
concentration of nutrients in the ponds rather than to the number of
coliforms going into the ponds.
Small Scale System
The opposing viewpoints regarding the significance of coliforms and
the importance of inoculation are difficult to resolve using full
scale equipment. Removal or control of coliforms in secondary
influent and elimination of bottom deposits within the secondary ponds,
as sources of coliforms, were considered to be problems beyond the
scope of this study. As an alternative small scale treatment units
(Figure 12) were constructed to evaluate, under controlled conditions,
the relationships between coliform inoculation and the concentrations
of coliforms in secondary treatment ponds. Main stages of the
experimental unit (Figure 13) included:
Influent Settling - to prevent particles from getting into small bore
tubing and the metering pump.
48
-------
Influent Acidification - to reduce coliform concentrations.
Neutralization - to adjust influent back to its original pH.
Aeration and Retention - to simulate secondary pond operation.
This sequence of operations is similar to that occurring in the full
scale operation when acidic by-products are being manufactured.
A control unit utilized only the first and last stages. Here, the
final aerated stage received approximately the same inoculation with
coliforms as did the large mill secondary ponds.
Components of the treatment systems and their retention times are
given in Table 11. A more complete description of the units and
their operation is provided in the Apparatus and Methods section.
Complete analytical data for the small scale units are given in
Table III in the Appendix.
Coliform concentrations were greatly reduced in the small scale
aeration unit, No. 9, by reducing the number of coliforms going into
it (Figure 14, Table 12). During the first 10 days the system had
several upsets and coliform kill in influent was erratic. From
October 16 on, operations were normal. This, plus the addition of
mechanical mixing to the acidification stage, led to further coliform
reductions in both influent and effluent. From October 24 on, coliform
reduction due to reduced inocula exceeded 99.8 percent. All coliforms
in influent were not killed by the acidification procedure even though
the pH was consistently below 2 (Table III, Appendix).
The total bacterial population in secondary influent also was greatly
reduced by the acidification procedure (Table 12). However, this had
no adverse effect on the total population in the aeration unit. Except
49
-------
Figure 12. Small scale waste treatment system.
so
-------
INFLUENT FROM
SECONDARY POND
JY1AN1FO
V
ACIDIFICATION (6, 7)
NEUTRALIZATION (8)
AERATION AND
RETENTION (9)
D (1-3)3
V
SETTLING (4, 5)
AERATION AND
RETENTION (10)
Figure 131 Main stages of small scale treatment system.
aNumbers refer to units shown in Figure 12.
51
-------
Table 11. COMPONENTS OF SMALL SCALE WASTE TREATMENT SYSTEM
Unit
no.
1
2
3
4
5
6
7
8
9
10
Description
Influent line
Constant level
head box
Waste basket
(flow director)
Settling basin 1
Settling basin 2
Acidification unit
Acidified influent
retention unit
Neutralization unit
Experimental aeration
unit
Control aeration unit
Capacity,
liters
700
40.8
Nil
99.5
56.0
53.2
76.0
48.4
234
(inc. heater)
242
(inc. heater)
Flow, L/min
minus excess
In
22
22
1.5
1.5
1.5
1.5
1.5
1.5
0.032
0.032
Out
22
1.5
1.5
1.5
1.5
1.5
1.5
0.032
0.032
0.032
Retention
time,
hours
0.53
0.031
Nil
1.1
0.62
0.54
0.83
0.54
122 (5.1 Days)
126 (5.25 Days)
rs>
-------
Table 11 (continued). COMPONENTS OF SMALL SCALE WASTE TREATMENT SYSTEM
Unit
no.
11
12
13
14
15
16
17
18
19
Description
Peristallic metering
pump
Acid reservoir
Caustic reservoir
Reserve acid supply
Reserve caustic supply
Recirculation and
aeration pump for 9
Heating unit for 9
Recirculation and
aeration pump for 10
Heating unit for 10
Capacity,
liters
--
50.0
50.0
3.8
3.8
b
-b
"b
b
*
Flow, L/min
minus excess
In
-a
a
-a
-a
a
--b
D
Q
b
Out
a
0.028
0.028
0.028
0.028
--b
^_b
"b
-b
Retention
time,
hours
a
29.8
29.8
0.23
0.23
Q
[J
t>
l>
U)
*No significant capacity or continuous flow.
"Included in value for aeration unit.
-------
Ul
10-
to
0ฑ
o
o
o
o
8-
6_
4-
2_
O ---- 0
A
COLIFORMS IN CONTROL UNIT INFLUENT
COL1FORMS IN EXPERIMENTAL UNIT INFLUENT
COLIFORMS IN CONTROL UNIT EFFLUENT
COLIFORMS IN EXPERIMENTAL UNIT EFFLUENT
O O
6 7 9
11 13 16 19 24 26 31 6 8
(1971) OCTOBER NOV
Figure 14. Effect of inoculation on coliform concentrations in effluents
from small scale treatment units.
-------
Table 12. EFFECT OF INOCULUM ON BACTERIAL CONCENTRATIONS IN SMALL
SCALE SECONDARY TREATMENT UNITS
Date
(1972)
Oct. 6
7
9
10
11
13
16
19
24
26
31
Nov. 6
8 |
Mean
(Exc. Oct. 6)
S.D.
Elap.
time,
days
Start
0.9
2.8
4.0
4.8
7.0
10.0
13.0
18.0
20.0
25.0
31.0
33.0 i
.-
Influent
Total bacteria
X lO'/lOO ml
Cont.
260
53
370
150
170
210
290
290
60
5.6
no
66
590
197
167
Exp.
0 .0004
0.0005
0.70
0.0030
0.0050
2.2
3.9
0.0004
0.0010
0.0020
0.049
0.0079
0.69
0.63
1.2
Red.,
7.a
>99.99
799.99
99.81
>99.99
>99.99
98.95
98.66
799.99
799.99
99.96
99.96
>99.99
88.31
99.68
_ Colifonns
x loYioo mi
Cont.
700
750
? 1000
2400
26
1000
900
1200
800
100
1600
1400
1000
71010
v
Exp.
CO. 0001
0.0007
2.9
0.022
0.060
20
3.6
0.0003
0.0006
-CO. 0001
0.18
0.007
0.69
<2.29
Red.,
7.a
y99.99
>99.99
->99.99
799.99
99.77
98.00
99.60
799.99
799.99
/ 99.99
7 99. 99
^99.99
99.93
799.77
__
Effluent
Total bacteria
X 10 '/100 ml
Cont.
490
320
40
220
180
200
730
590
140
520
1000
870
150
413
320
Exp.
360
270
28
200
280
500
13
880
170
940
820
620
110
403
338
Red.,
%a
_b
15.6
30.0
9.1
+56
+150
98
+49
21
+81
18
29
27
2.4
__
Coliforms
X 105/100 ml
Cont.
130
80
230
680
600
120
170
80
160
140
130
120
13
210
208
Exp.
130
6.0
5.0
1.2
0.70
6.3
19
3.4
0.31
0.24
0.029
0.014
0.060
3.52
5.45
Red.,
%a
92.50
97.83
99.82
99.88
94.75
88.82
95.75
99.81
99.83
99.98
99.99
99.54
98.32
3.82
"Percent reduction due to influent treatment.
b -- Not measured or calculated.
Ln
tn
-------
for October 16, total bacteria concentrations were similar for the two
small scale aeration units and the mill secondary ponds (Figure 15).
Results from this experiment showed that coliforms, at least in high
concentrations, were not normal inhabitants of the small aeration
units. This suggests the possibility that coliforms might be reduced
to acceptable concentrations in the large aerated lagoons if a practical
way could be found to reduce their numbers in the influent.
Direct Effects
The pH of secondary ponds varied little during the project. The mean
of 104 samples was 7.1 * 0.5 S.D. (Table 5). Only during three brief
periods in June and July, 1972 did the pH fall below 6.0. Between
June 15 and 20 the pH dropped to a low of 5.6 but coliform concentra-
tions remained in the range of normal variation (Figure 11). Similar
situations and results were found on July 5, 6, and 11. pH values in
the range of 5.4 to 5.7 had no immediate adverse effect on coliform
populations. However, it may be significant that coliform populations
reached their lowest level of the entire project about 10 days after
the last interval of low pH. Microscopic observations made during
periods of low pH showed a qualitative shift in microorganisms away
from spirilla, vibrios and prosthecate bacteria toward cocci, non-
motile rods, yeast and protozoa. This suggests that low pH led to a
slow change in the balance of microorganisms, temporarily favoring
predators of coliforms. The cyclic nature of coliform populations
(Figure 11) suggests a predator-prey relationships, however, other
factors such as varying concentrations of coliforms in secondary
influent may be responsible for this.
The highest pH values of secondary effluent, 7.3 to 7.4, had no
adverse effect on coliform concentrations (Table I, Appendix).
56
-------
10 -I
Ui
DC:
LU
O
<;
00
8 .
2 .
o-
A
--O
A
TOTAL BACT
TOTAL BACT
TOTAL BACT
COLI FORMS
COLI FORMS
COLI FORMS
IN SMALL CONT UNIT
IN SMALL EXP UNIT
IN MILL EFFLUENT
IN SMALL CONT UN IT
IN SMALL EX PUN IT
IN MILL EFFLUENT
(1972)
Figure 15. Comparison of concentrations of bacteria in mill
and small scale systems.
10 11 13 16 19 24 26 31 6 8
OCTOBER NOV
-------
Indirect Effects
There is an indirect pH effect which merits consideration. Experiments
with small scale apparatus (Table III, Appendix) showed that acidifi-
cation greatly reduced coliforms in secondary influent. When the
acidified influent was neutralized and fed to an aeration unit,
colifonn regrowth was negligible. In fact, there was rapid die off of
those initially present (Figure 14). These processes of influent
acidification and retention, followed by neutralization and transfer
to aeration units have their counterparts in full scale mill operations.
Approximately 40 percent of the total mill waste is utilized to establish
the "water leg" for an evaporator used in the manufacture of commercial
lignosulfonates. When acidic grades are being produced, SO^ volatilizes
from spent sulfite liquor within the evaporator and dissolves in the
mill waste "water leg". This stream in turn combines with other
wastes which are fed to the primary settling pond (Figure 16). This
constitutes the influent acidification stage. The SO lowers the pH
of the "water leg" to pH 2-3 (Table 13). Combined waste, which is
equivalent to secondary influent before neutralization, may have pHs
in the range of 3-4 (Table 14). Following a 2-6 hour retention in
the primary pond the waste is neutralized as it flows to the secondary
treatment ponds.
Storage tests (Table 14) showed that coliform concentrations were low
in pH 3.8-4.0 primary effluents and were reduced to less than 100/100 ni
within 24 hours at 2ฐ C.
Circumstantial evidence indicates that coliform concentrations in mill
secondary effluent can be reduced by limiting their concentration
going into the ponds. Acidification and retention stages to kill
coliforms in secondary influent were demonstrated in small scale and
mill systems. It was further shown that this reduced coliforms in
See Glossary.
58
-------
PAPER MACHINE
WASTE
60%
40%
STRONG SPENT
SULFITE LIQUOR
EVA P.
WATER
LEG
<-S07 EVAPORATOR
OR^FOR BY-PRODUCT
<-NH3 MANUFACTURE
COMMERCIAL
LIGNOSULFONAIES
v
v
PRIA/IARY SETTLING POND
SECONDARY AERATION PONDS
WEAK SPENT
SULFITE LIQUOR
Figure 16. Flow of mill wastes.
-------
Table 13. EFFECT OF BY-PRODUCT MANUFACTURE ON pH OF MILL WASTE
USED IN EVAPORATOR"WATER LEG"3
By-product prod.
UrzanR
grade
AL
GL
KSL
LS
Approx.
PH
4
4
7
7
# of
samp .
26
42
28
2
pH of mill waste
Before'Wter leg"
Min.
4.30
5.80
5.90
8.00
Max.
8.30
9.80
10,20
8.20
Mean
6.86
7.25
7,61
8.10
S.D.
0.75
0.82
1.02
-b
After"water le
Min.
1.90
2.10
6.50
7.80
Max.
3.70
3.60
9.80
8.30
Mean
2.34
2.65
7.90
8.05
f4"
S.D.
0.57
0.41
0.93
--
-- Not calculated.
-------
Table 14. EFFECT OF pH ON CONCENTRATIONS OF COLIFORMS
IN MILL WASTES STORED AT 2ฐ C.
Sample
Primary
inf. (9/14/71)
Primary
inf. (9/16/71)
Primary
eff. (9/14/71)
Primary
eff. (9/16/71)
Secondary
inf. (9/14/73)
pH
Ini.
9.0
9.0
3.8
3.8
8.8
8.8
4.0
4.0
8.7
Adi.
__a
7.0
7.0
7.0
7.0
--
Coliforras/100 ml
Initial
116 X 104
30 X 104
39 X 102
20 X 103
38 X 104
20 X 104
67 X 102
33 X 103
43 X 104
24 Hrs.
120 X 10*
121 X 104
^ 100
91 X 102
40 X 104
78 X 105
<100
82 X 102
27 X 104
48 Hrs.
60 X 104
165 X 104
-<100
46 X 10J
79 X 104
76 X 105
*, 100 ,
18 X 10J
30 X 105
Colifonn red'n., %
24 Hrs.
0
0
-;> 97
54
0
0
:>98
75
37
48 Hrs.
48
0
-r 97
0
0
0
^ 98
45
0
a _.
pH not adjusted.
-------
effluent from small scale units. It was desired to demonstrate this
last relationship in the mill systems but for the following reason
this proved difficult:
Several types of lignosulfonates are produced. However, only with
acidic grades are conditions established for significant coliform
kill (Table 13). With alkaline grades, NH rather than SO is
volatilized from evaporating spent sulfite liquor and the pH of mill
wastes is increased (Tables 8, 14). High pH influents are relatively
non-toxic to coliforms (Table 14). An attempt was made to maintain
continuous production of acid by-products and to evaluate the effect
on coliforms in secondary effluent. It was not successful because of
unforeseen requirements for various products (Table 15).
Table 15. BY-PRODUCT EVAPORATOR OPERATING SCHEDULE
Date
(Dec. 1971)
14
15
16
17
18
19
20
21
22
23
24
Mean
Percent of production time
Low pH
products
61
25
92
66
31
41
60
73
76
68
56
59
High pH
products
34
74
7
14
67
57
40
25
23
0
42
35
Not in
operation
5
1
1
20
2
2
0
2
1
32
2
6
62
-------
TEMPERATURE
Mean monthly temperatures of secondary effluent ranged from 13ฐ C.
in December 1971 to 29ฐ C. during July and August of 1972 (Table I,
Appendix). Mean coliform concentrations varied from month to month
(Figure 17), however variations in counts for samples within a given
month frequently exceeded the greatest difference between means of
different months. Factors responsible for these individual variations
would mask lesser effects due to temperature.
DISSOLVED OXYGEN
Aerated Basins
Measurements made on July 13, 1972, showed that secondary ponds were
not completely mixed with respect to pH or dissolved oxygen concentra-
tions (Figures 18 and 19). The possibility was investigated that
coliform populations could be influenced by differences in oxygen content
in poorly mixed locations within the ponds. Results obtained on Pond 1
samples, taken August 2, suggested that low D.O. concentrations
favored coliform growth whereas high D.O. levels increased growth of
other types of bacteria (Table 16). Coliforms comprised 11.5 percent
of the total bacterial population in low D.O. ('".0.3 ppm) samples and
4.2 percent for high (~7 2 ppm) D.O. samples. Variations in bacterial
concentrations were less among low D.O. samples or among high D.O.
samples than for the entire sampling. Similar results were found
for Pond 2 but differences were slight (Table 17).
Small Scale System
At the end of the previous experiment with small scale equipment, on
November 8, the control unit (No. 10) had a coliform concentration of
1.3 million cells/100 ml and the experimental unit (No. 9) had
6 thousand/100 ml (Table 12). The low coliform concentration was
63
-------
a:
O
O
o
o
O
8-
7-
6-
COLIFORMS
MIN
MEAN TEMP.
ฐC
A
T 'T
i *' *
x^. -1-/
\ /
^
30-
20-
10-
1971 SEPT DEC FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV 1972
SAMPLE DATE
Figure 17. Relationship between secondary effluent temperature and coliform
concentrations.
-------
INFLUENT
B T C
D
1
k
1.
2-
3-
863' 4-
<
5-
6-
7-
>
7.23 7.2 7.0 7.4 7.4
0.4 0.3 0.8 0.8 0.8
O ฃ| 6.8
0.4 o 7
O 6-7
^ 0.8
7.1 6.8 6.7 6.7 6.7
0.5 0.5 0.7 0.7 0.7
M 6,6 66 66 66
ฐ*4 ^ 1.2 1.0 I.I
O o
6.5 6.6 6.5 6.6 6.6
23 O O O H
0 o
6.6 6.6 6.6 6.6 6.6
2.9 2.9 3.0 3.0 3.C
O
6.5 6.5 6.5 6.5 6.i
2.4 2.7 2.8 2.8 2.1
6.4 6.4 6.4 6.4 6.4
2.4 2.6 2.8 2.6 2.4
D, 0. ppm
O75hp
AERATOR
296'
Figure 18. Dissolved oxygen and pH of waste in Pond I.
65
-------
7031
A
i
1-
2-
3-
4-
5-
6-
7-
6.9a
0.2
7.0
O.I
6.6
O.I
6.5
O.I
6.5
0.5
6.4
1.7
6.4
1.9
6.4
1.9
B
i
6.9
0.2
6.6
0.4
6.5
2.0
6.4
2.2
6.4
2.3
6.5
2.3
6.5
2.3
6.4
2.0
INFLUENT
ci
i
6.7
O.I
.8
e
c /
^-^
6.5
2.6
6.4
1.7
6.4
TTJ
O
6.4
2.3
6.4
1.3
D
I
7.3
O.I
6.8
0.3
6.5
1.6
6.5
2.3
6.9
0.2
6.5
2.0
6.4
2.2
6.4
1.4
E
i
7.0
O.I
7.0
O.I
6.9
0.2
7.0
O.I
6.5
1.3
6.5
1.5
6.5
1.9
6.4
1.4
aDH
D.O. ppm
Q75hp
\ERATOR
357'
Figure 19. Dissolved oxygen and pH of waste in Pond 2.
66
-------
Table 16. EFFECT OF DISSOLVED OXYGEN CONCENTRATION ON BACTERIA IN POND 1
Sample
point8
C - 0.5
B - 0.5
C - 2.5
C - 3.5
C - 6.0
D - 6.2
C - 7.5
Mean
S.D.
Var., %
Total sampling
D.O.,
ppm
0.15
0.30
0.10
0.75
2.50
3.40
2.50
1.67
1.41
84
Bacteria/100 ml
Total
X 10?
182
153
156
198
325
244
217
211
60
28
Colif.
X 106
180
175
204
106
114
120
88
141
44
31
Colif.
%
9.9
11.4
13.1
5.4
3.5
4.9
4.1
7.5
3.9
52
Low D.O. samples
D.O.,
ppm
0.15
0.30
0.10
--
--
--
--
0.20
0.11
55
Bacteria/100 ml
Total
X 107
182
153
156
-.
--
.-
186
16
9
Colif.
X 106
180
175
204
--
--
..
164
16
10
Collf.,
%
9.9
11.4
13.1
--
_-
--
._
11.5
1.6
14
High D.O. samples
D.O.,
ppm
b
._
..
--
--
2.5
3.4
2.5
2.8
0.52
19
Bacteria/100 ml
Total
X 10?
..
_-
--
325
244
217
262
56
21
Colif.
X 106
--
--
--
114
120
88
107
17
16
Colif.,
'/.
--
.-
--
--
3.5
4.9
4.1
4.2
0.70
17
aRefers to coordinates in Figure 18.
-- Not measured or calculated.
-------
Table 17. EFFECT OF DISSOLVED OXYGEN CONCENTRATION ON BACTERIA IN POND 2
Sample
point*
C - 6.8
C - 6.0
C - 4.8
C - 3.5
C - 3.0
C - 1.5
C - 0.8
E - 0.2
C - 0.2
Mean
S.D.
Var., 7.
Total sampling
D.O.,
ppm
0.30
2.10
2.10
2.10
1.90
1.70
0.60
0.20
0.10
1.23
0.90
73
Bacteria/100 ml
Total
X 10?
282
276
268
234
233
214
182
213
191
233
36
15
Colif .
X 105
90
94
60
100
92
172
116
150
126
111
34
31
Colif.,
7.
3.2
3.4
2.2
4.3
3.9
8.0
6.4
7.0
6.6
5.0
2.0
40
Low D.O. samples
D.O.,
ppm
0.30
--
..
-.
_.
_ ซ
_ ซ
0.20
0.10
0.20
0.10
50
Bacteria/100 ml
Total
X 10?
282
..
* .
,-
. _
,*
~~
213
191
229
47
21
Colif.
X 106
90
*-
_-
-.
. .
* *
_ .
150
126
122
30
25
Colif.,
%
3.2
.-
..
..
._
..
-.
7.0
6.6
5.6
2.1
38
High D.O. samples
D.O.,
ppm
__b
2.10
2.10
2.10
__
._
..
-.
--
2.10
0
0
Bacteria/100 ml
Total
X 107
* <
276
268
234
..
-ป
Hf
--
--
259
22
8
Colif.
X 10*
*n m
94
60
100
-.
_.
_.
--
--
85
22
26
Colif. ,
%
..
3.4
2.2
4.3
..
_.
..
..
..
3.3
1.1
33
aReฃers to coordinates in Figure 19.
-- Not determined or calculated.
-------
achieved by reducing their numbers in the influent to unit No. 9.
Both units remained aerobic during this test but D.O. levels fluctuated
(Table III, Appendix) and differences in coliform levels between the
two units could not be related to differences in D.O.
In this trial new conditions were established to evaluate oxygen
effects. Influent acidification stages were eliminated so that both
aeration units received coliforms in settled influent. Aeration to
unit 10 was increased to determine if a high concentration of D.O.
could reduce the coliform population. A relatively low D.O. level
was maintained in unit 9 to determine if the initially low coliform
population would be stable under conditions simulating those present
in the large aeration basins.
Throughout the experimental period from November 8-21, D.O. in unit
10 was between 7 and 8 ppm. In unit 9 it was maintained at 1-2 ppm
until November 19 when its recirculation pump failed. Although the
coliform concentration in unit 9 was very low at the start of the
experiment, within 4.8 days it greatly increased and exceeded that
found in the highly aerated unit (Table 18). These results and those
obtained after 7.7 days of operation indicate that dissolved oxygen
does have an effect on coliform populations. Low D.O. levels stimulate
growth and/or high levels repress growth. More likely, high D.O.
levels stimulate other microorganisms which grow better at low nutrient
levels and may inhibit coliform growth or are predators upon them.
After 12.8 days of operation, coliforms in the highly aerated unit had
dropped to 400 thousand/100 ml. This is a very low concentration
compared to values obtained from analyses of numerous mill secondary
effluent samples (Table 5). Unfortunately comparisons could not be
made with the low D.O. unit because of its recirculation pump failure.
However, the coliform concentration in the small highly aerated unit
69
-------
Table 18. EFFECT OF DISSOLVED OXYGEN CONCENTRATION ON BACTERIA
IN SMALL SCALE AERATION UNITS
Elaps.
time
days
0
1.9
4.8
7.7
9.8
12.8
D.O., ppm
Small unit
9
2.0
2.2
1.2
1.2
1.7
--
10
8.0
7.9
8.0
7.4
8.4
7.7
Total bact./lOO ml X 107
Small unit
9
110
ปa
2400
300
--
--
10
150
--
1100
680
--
1600
Mill
sec. eff.
240
--
880
200
--
200
Colif./lOO ml X 105
Small
9
0.06
--
230
36
--
--
unit
10
13
--
94
13
--
4
Mill
sec. eff.
620
--
200
60
--
80
Colif.. 7. of total
Small unit
9
<0.001
--
0.10
0.12
--
--
10
0.09
--
0.09
0.02
--
0.003
Mill
sec. eff.
2.6
--
0.23
0.30
--
0.40
a -- Not determined or calculated,
-------
was only 5 percent of that in mill secondary effluent while its total
bacterial population was considerably greater (Table 18). This is
another indication that highly aerobic conditions minimize, perhaps
indirectly, the development of high coliform concentrations in
secondary treatment units.
In this experiment and the preceeding one with small scale equipment,
and over extended periods in the mill treatment system, coliform
concentrations in influent samples exceeded those found in effluent
samples (Table 19). The problem with coliforms appears not to be
one of growth in secondary aeration basins but rather one of
minimizing inoculation of the ponds with coliforms and in establishing
conditions which favor coliform antagonists or predators. High D.O.
levels appear to help with the latter.
EPA Unit*
The combination of high D.O. levels and low coliform populations was
found in another system. This was in a small unit located at the
Lebanon mill and operated by personnel of the Environmental Protection
Agency (EPA), Corvallis, Oregon. Retention time for this unit was
approximately the same as for the large ponds but it differed in two
other respects. Influent bypassed the primary pond and the aeration
unit was operated at high D.O. levels. During a 40 day test period
its mean D.O. concentration was 8.0 ppm - S.D. 0.8 (Table 20). The
mean concentrations of total bacteria and coliforms were 3,320 million/
100 ml and 0.85 million/100 ml, respectively. Total bacterial
populations were approximately the same as for the mill ponds during
the same period but the mean coliform concentration was only about
2 percent of that found for mill effluent and most values were less
than 0.1 percent. Coliform levels in the EPA unit were comparable
to those found in the highly aerated small scale unit described earlier
(Table 18).
*See glossary.
71
-------
Table 19. COMPARISON OF BACTERIAL CONCENTRATIONS IN SECONDARY INFLUENT AND EFFLUENT
Source
of
Mill
Secondary
Treatment
System
Small Unit 9
Small Unit 10
Small Unit 9
Small Unit 10
Date
Sept. 1971
Dec. 1971
March 1972
April 1972
June 1972
July 1972
Aug. 1972
Sept. 1972
Oct. 1972
Nov. 1972
Mean (Total)
Exp. 1, Oct. 6
to Nov. 8
Exp. 2, Nov. 8
to Nov. 21
Number of sample*
Influent
Total
1
5
8
2
8
0
5
8
14
7
(58)
13
10
3
3
Collf
1
6
8
1
8
7
10
8
15
7
(71)
13
10
3
3
Efflt
Total
6
6
8
3
8
3
5
5
14
3
(61)
12
13
2
3
ient
Collf
6
7
8
3
11
12
9
5
14
3
(78)
12
13
2
3
Total bact./lOO ml
X 10?
Inf.
70
9
29
^.1
26 a
16
28
61
140
46
0.58
225
148
148
Eff.
197
132
110
104
503
427
564
130
312
720
355
402
419
1350
1130
Collf. /100 ml
X 105
Inf.
4
20
518
1
272
7
953
338
1590
873
686
2.1
1780
627
627
Eff^
39
37
215
533
217
125
335
240
483
317
266
3.5
361
133
37
Ratio of inf.
to eff
Total
0.36
0.07
0.26
^0.01
0.05
-
0.03
0.22
0.20
0.19
0.04
0.001
0.54
0.11
0.13
. bact.
Colif
0.10
0.54
2.41
^.0.01
1.25
0.06
2.84
1.41
3.29
2.8
2.1
0.60
4.93
4.71
16.9
a Not determined or calculated.
-------
Table 20. CONCENTRATION OF BACTERIA IN SECONDARY EFFLUENT
FROM EPA UNIT AND MILL AERATION BASINS
Date
(1972)
Oct. 10
11
16
19
24
26
31
Nov. 6
8
13
16
21
30
Mean
S.D.
EPA
unit
D .0 . f ppm
8.7
9.6
7.3
7.7
8.0
7.3
9.1
8.1
8.2
7.3
7.2
7.4
7.7
7.97
0.76
Bacteria/100 ml
Total X I0y
EPA
230
410
100
860
160
590
290
320
250
490
300
310
6
332
221
Mill
360
310
240
210
320
600
640
320
240
880
200
200
970
422
264
Colif. X 105
EPA
1.2
2.4
30
42
10
2.0
0.3
0.4
0.7
1.5
1.9
2.7
16
8.5
13
Mill
520
260
770
440
240
370
230
210
620
200
60
80
920
378
264
Ratio of bact.
EPA: Mi 11
Total
0.64
1.32
0.42
4.10
0.50
0.98
0.45
1.00
1.04
0.56
3.00
1.55
0.01
0.79
1.22
Colif.
0.002
0.009
0.039
0.095
0.042
0.005
0.001
0.002
0.001
0.008
0.032
0.034
0.017
0.022
0.027
Although high aeration rates reduced coliform concentrations in
secondary aeration units, the order of magnitude was not great enough
to provide a practical coliform control method.
Sediments
In the absence of dissolved oxygen, coliform concentrations became
extremely high in the settling stages of the small waste treatment
system. Mean concentrations were 9.3 billion and 4.35 billion per
100 ml in bottom samples from units 4 and 5 respectively (Table 21).
A high concentration of 60 billion/100 ml was found on October 16.
Although no D.O. measurements were made the lack of oxygen was attested
to by strong H-S odors in bottom samples and low, 0.1-0.3 ppm, D.O.
levels measured at the upper surfaces of the settling units (Table III,
Appendix).
73
-------
Table 21. BACTERIAL CONCENTRATIONS IN SETTLING STAGES
OF SMALL SCALE UNITS
Date
(1972)
Oct. 16
19
31
Nov. 6
8
13
16
21
25
30
Mean
S.D.
Total bacteria/100 ml X 107
Bottom
Unit 4
11,700
6,400
4,000
2,700
5,500
1,100
3,900
430
490
1.100
3,730
3,500
samples
Unit 5
7300
4400
4000
3800
2900
1700
3700
940
1200
150
3010
2110
Top samples
Unit 4
360
330
100
230
540
62
550
3
5400
65
764
1640
Unit 5
290
290
110
66
590
110
280
9
690
1000
344
320
Colifonns/100 ml X 105
Bottom samples
Unit 4
600,000
56,000
33,000
32,000
130,000
10,000
10,000
2,200
5,400
53.000
93,000
182,000
Unit 5
140,000
62,000
24,000
17,000
100,000
17,000
51,000
15,000
4,700
3.900
43,500
45,000
Top samples
Unit 4
11,000
1,100
1,500
2,600
12,000
480
560
100
60,000
600
8,990
18,500
Unit 5
9000
1200
1600
1400
1000
560
2800
630
6400
3100
2770
2800
-------
Bacterial populations, including coliforms, in bottom samples were
approximately 10 times greater than found in surface samples. This
was probably not due to low D.O. per se but rather to the enriched
environment at the bottom of the tank. Bacteria present in influent
settle with fibers and increase in concentration through this process.
In addition, autolysis of microorganisms would supply organic nitrogen and
growth factors. The settled material also has a significant retention
time whereas surface samples do note The time required to produce
the high concentrations of bacteria was not determined, however, they
were present in the first bottom samples taken which was after 10 days
of operation.
The development of coliforms in settled materials may be significant
in mill operations. For example, sludge beds in the primary pond
could contribute to the inoculation of the aeration basins and also
protect bacteria within the interior against the toxic effect of
periods of high acidity.
In secondary ponds, sludge beds form in quiescent areas and it is
probably that their coliform concentrations are high0 This would be
an internal source of inoculum. Repositioning of aerators to disperse
sludge might have the temporary effect of increasing coliform concen-
trations in the effluent. Occasional high coliform counts found in
secondary effluent samples may have been due to resuspension of sludge,,
There is a mill recycle system which is conducive to coliform
development. Fibers from the primary pond sidehill screen, along with
nutrients and coliforms in the associated liquid, are transported to
the mill and stored in a large bin. Before the fibers are used,
anaerobic conditions develop and coliforms increase. This will be
discussed more fully in the section on Sources of Coliforms.
75
-------
BOD
In August 1972, secondary effluent had some of the lowest and highest
coliform concentrations found during the project (Table I, Appendix).
During this period, influent BOD varied from 310 to 470 ppm but effluent
BOD was relatively stable in the range of 65 to 95 ppm. There was no
direct relationship between changes in BOD load to the secondary ponds
and coliform concentrations in secondary effluent (Figure 20). Changes
in coliform concentrations in secondary influent however, did correlate
well with those occurring in secondary effluent. A similar situation
was found in October 1972. Between the 13th and 18th, coliform
concentrations increased from 29 million to 150 million/100 ml
(Table I, Appendix). There was no significant change in influent or
effluent BOD during the period but coliform concentrations in secondary
influent increased from 29 million to 1.1 billion/100 ml (Table II,
Appendix). These results again indicate that inoculation of secondary
ponds with coliforms is the main factor which influences coliform
concentrations in secondary effluent. The BOD of wastes being
treated in secondary ponds can be changed by going from a parallel to
a series operation. The effect that this has on coliforms is discussed
in the following section.
SERIES VS PARALLEL POND OPERATION
A switch from parallel to series operation definitely changed several
characteriatics of wastes within the ponds. However, no direct
relationship could be established between the method of pond operation
and coliform concentrations in the effluent.
Just prior to switching from parallel to series operation on November
16, coliform concentrations in Ponds 1 and 2 were 25 million and 6
million per 100 ml, respectively (Table 22). Higher concentrations
also were found in Pond 1 after 3 days and 8 days of series operation.
76
-------
COL I FORMS
BOD
9 -,
i
i
8
7
on
o
o ,
o 6
o
o
INFLUENT
EFFLUENT
INFLUENT
EFFLUENT
25
30
5 10 15 20
AUGUST -1972
Figure 20. Relationship between BOD and coliform concentrations
-------
Table 22. COMPARISON OF SECONDARY EFFLUENT CHARACTERISTICS
FROM SERIES AND PARALLEL POND OPERATION
Analysis
PH
Temp. ฐC.
S03ป PPm
BOD, ppm
Total bact.
per 100 ml
X 107
CoHforms
per 100 ml
X 105
Sample
source
Pond 1
Pond 2
Comb .
Pond 1
Pond 2
Comb.
Pond 1
Pond 2
Comb .
Pond 1
Pond 2
Comb.
Pond 1
Pond 2
Comb.
Pond 1
Pond 2
Comb.
Coliform Ratio--Pl:P2
Mode of pond operation and date (Nov. 72)
Parallel
6
__a
6.8
20.0
4.3
92
320
210
--
8
< Hป
6.8
20.4
3.7
126
240
620
--
13
7.0
6.6
6.9
21.9
21.3
21.6
3.3
3.3
3.2
193
126
130
1900
1400
1600
390
80
120
4.9
Series
16
7.5
7.1
24.4
20.8
78.0
2.4
240
125
300
200
250
60
4.2
21
7.4
7.0
25.7
21.2
86.0
3.0
237
110
280
200
180
80
2.2
25
7.3
7.0
25.0
18.4
64.0
4.7
185
94
43
470
730
1800
0.41
Parallel
30
7.2
6.6
7.0
19.8
19.7
19.8
20.0
4.0
7.9
108
380
1000
970
150
700
920
0.21
00
a -- Not determined.
-------
Within the next 4 days, however, the situation reversed. Coliforms
became more numerous in Pond 2 and their populations were greatly
increased in both ponds. The sharp increase on November 25 was most
likely caused by an increase in coliforms in influent (Figure 21).
The reason for the reversal in relative coliform populations in the
two ponds is more difficult to explain. It may have been unrelated
to the method of operation as similar reversals have occurred during
continuous parallel operation, e.g., July 31 to August 8 (Table IV,
Appendix). It was apparent, however, that 12 days of continuous
series operation did not reduce coliforms in secondary wastes to
acceptable levels.
The following changes were related to the shift from parallel to
series operation (Table 22):
Pond 1 became approximately 5 C. warmer because it received warm
influent and was exposed to cold ambient air for a shorter time.
The BOD level in Pond 1 approximately doubled but stayed about the
same in Pond 2.
Sulfite concentrations remained at 3 to 4 ppm in Pond 2 but increased
to approximately 80 ppm in Pond 1. In other studies (Table 23) it
was found that removal of S0~ from mixtures of secondary influent and
effluent was related to microbiological oxidation. From the determined
oxidation rate of 1.34 ppm/hr (SO- >SOA ) and tne mean SO, concen-
tration in influent of 142 ppm (Table 8) it can be calculated that
approximately 4.3 days would be required for the complete oxidation.
The increase in SO ~ in Pond 1 during series operation was probably due
to its insufficient retention time of 2.5 days. On the basis of oxygen
uptake rates, the relatively high SO., levels in Pond 1 had no adverse
effect on microorganisms (Table 24, Figure 22). In fact, the rate of
79
-------
CONFORMS
"
'
10-
00
01
o
O
O
o
o
8-
6-
4-
a INFLUENT Lb POND
, POND 2
POND CONFIGURATION
rf PARALLEL ^ SERIES ... L^,
|
^^
r ^-i
^^^^^^^^^s
|
^
^
i
^^H
I
. _ -_
- ซ
|
\
IHHM
8
I3NOVEMB^(I972) 2'
30
Figure 21. Coliform concentrations during series and parallel pond operation.
-------
Table 23. OXYGEN UPTAKE AND SULFITE OXIDATION BY MIXTURES
OF SECONDARY INFLUENT AND EFFLUENT
Sample and
analysis made
D .0 . 7 ppm
Unheated sample
Heated sample
Sulfite, ppm
Unheated sample
Heated sample
Total D.O. uptake, ppm
Unheated sample
Heated sample
Total 503* oxid., ppm
Unheated sample
Heated sample
D.O. uptake, ppm/hr.
Unheated sample
Heated sample
SOg* oxid., ppm/hr.
Unheated sample
Heated sample
Effect of heating on:
D.O. uptake, 70 red'n.
303* oxid., 7. red'n.
Values for reaction times of:
Initial
9.4
9.4
81.8
55.4
--
--
> ป
32
1 Hr,
7.5
9.4
81.3
54.4
0.9
0
0.5
1.0
0.9
0
0.5
1.0
+50
2 Hrs.
5.5
9.2
80.4
53.9
3.9
0.2
1.4
1.5
2.0
0.2
0.9
0.5
90
45
3 Hrs.
3.8
9.0
78.4
54.4
5.6
0.4
2.4
1.0
1.7
0.2
2.0
-0.5
88
4 Hrs.
1.6
8.7
77.4
54.4
7.8
0.7
3.4
1.0
2.2
0.3
1.0
0
86
6 Hrs.
0.4
8.3
74.0
52.4
9.0
1,1
7.8
3.0
0.6
0.2
1.7
1.0
41
7 Hrs.
0.2
8.1
72.5
51.9
9.2
1.3
9.3
3.5
0.2
0.2
1.5
0.5
67
10.5 Hrs.
a
67.6
50.0
--
14.2
5.4
*
1.4
0.5
64
00
a -- Not determined.
-------
Table 24. OXYGEN UPTAKE BY SECONDARY EFFLUENT SAMPLES
FROM SEMES AND PARALLEL OPERATION
Pond
conf .
Series
for 8
days
Parallel
for 2 days
following
series
operation
Sample
source
Pond 1
Pond 2
Pond 1
Pond 1
Pond 2
Pond 2
BOD
ppm
285
152
200
200
109
109
Dissolved oxygen, ppm
after:
Ini.
8.20
8.85
8.75
9.20
9.40
9.50
15 Min.
6.30
8.25
8.05
8.25
8.90
--
30 Min.
4.55
7.80
7.25
7.45
8.30
8.45
1 Hr.
1.30
7.00
6.00
6.00
7.60
7.75
2 Hrs.
0.40
5.20
3.30
3.20
6.20
6.35
3 Hrs.
0.15
3.50
__a
--
ซ ซ
02,
uptake,
ppm
hr.
6.90
1.85
2.75
3.20
1.80
1.75
Ratio
02 uptake
rate:
BOD
0.024
0.012
0.014
0.016
0.017
0.016
00
N3
* Not determined,
-------
E
a
a
o
i
o
CO
GO
UJ
Q_
O
Cฃ
Q-
Q_
O
on
LU
CO
OO POND I
AA POND 2
ป 1
L
0 0.25 0.50 1.0 1.5
ELAPSED TIME, hours
2.0
Figure 22. Oxygen uptake by secondary effluent from
series and parallel pond operation.
83
-------
oxygen uptake was greatest for Pond 1 effluent from series operation.
This was due in part to a higher BOD concentration.
Microscopic observations showed that the shift to series operation
caused a qualitative change in the microbial population. After 2 days
of series operation, wet mounts of samples from Pond 2 showed 5 to 10
protozoa per field under 150x magnification compared to less than one
per 10 fields in samples from Pond 1. Pond 2 samples also were dis-
tinguished by relatively high concentrations of small spheres which
resembled in size and configuration the granules seen in large spirilla.
Following a change back to parallel operation, the bacterial populations
of the ponds became similar and protozoa disappeared from Pond 2
effluent.
RETENTION TIME IN SMALL SCALE SYSTEM
On November 21 influent flow to small aeration unit 10 was doubled.
This reduced the retention time to 2.5 days which was equivalent to
that of mill Pond 1 when in series configuration. At the start of the
test, the coliform concentration was less than one million per 100 ml
and was only 230,000 per 100 ml after 4 days. Levels increased to
approximately 4 million/100 ml during the next 5 days. This was within
the concentration range found earlier with a 5 day retention time
(Table 25). Regardless of retention time, coliform levels in the
effluent were consistently less than those in influent samples
(Figure 23).
There were some interesting differences in the ways in which the small
aeration unit and mill Pond 1 responded to reduced retention time
(Table 26). After 9 days, the most significant differences were the
large increase in SO ~ concentration, from 3.3 to 64 ppm, in Pond 1
and its high BOD of 185 ppm. During shorter retention BOD values for
84
-------
Table 25. EFFECT OF RETENTION TIME ON CHARACTERISTICS
OF EFFLUENT FROM SMALL SCALE UNIT
Analysis
PH
Temp. ฐC.
S03, ppra
BOD, ppm
D.O., ppm
Total bact.
per 100 ml X 107
Coliforms -
per 100 ml X 10
Colif., Z of
total bact.
Retention time and date (Nov. 1972)
5 Days
6
6.6
20.5
2.6
69
2.8
870
120
0.14
8
6.5
19.8
2.5
57
4.4
150
13
0.09
13
7.8
22.6
3.0
78
8.0
1100
94
0.09
16
7.2
24.0
2.9
104
7.4
680
13
0.02
21
7.2
23.8
2.8
87
7.7
1600
4
0.003
2.5 Days
25
6.9
23.9
4.5
73
8.2
2800
2.3
0.001
30
6.4
20.0
2.9
109
8.2
2900
36
0,12
00
01
-------
COL! FORMS
00
10.
CO
^
Qฃ
O
O
o
CD
r I
O
O
8 .
A
_. 0 J
ฃ2 INH_UtNI LJ tri"LL
RETENT ION TIME
^ 5 davs \
i
i
m^m
I
MM
I
^^^^^^^^^^^^oc^^x^^^^^os^^ \
ItlNI
L, 2. 5 davs 0
^
MBH
\
maim
* A
^
1HM
8
13 16
NOVEMBER (1972)
21
25
30
Figure 23. Effect of retention time on coliform concentrations
in small scale treatment units.
-------
Table 26. EFFECT OF RETENTION TIME ON CHARACTERISTICS OF
EFFLUENTS FROM SMALL SCALE AND MILL AERATION UNITS
Measurement
and
treatment unit
ฃS
Pond 1
Small unit
Temp , C .
Pond 1
Small unit
SO,,, ppm
Pond 1
Small unit
BOD, ppm
Pond 1
Small unit
D.O., ppm
Pond 1
Small unit
Retention time,
days
5
7.0
7.2
21.9
23.8
3o3
2,8
193
87
7.7
2.5
7.3
6.4
25.0
20.0
64.0
2.9
185
109
8.2
Change during
reduced retention
Units
+ 0.3
- Oo8
+ 3.1
- 3.8
+60.7
+ 0.1
- 8
+22
0
Percent
__b
+1800
+ 4
- 4
+ 25
0
After 9 days of
-- Not done or
lower retention time.
calculated.
Pond 1 reached 240 ppm (Table 22). In contrast S03 concentrations
in the small unit remained at approximately 3 ppm and the BOD was still
a relatively low 109 ppm. The ability to maintain good performance
with only half the normal retention time was probably due to high D.O.
concentration and complete mixing.
INTERACTIONS
In the preceeding sections attempts were made to evaluate the effect
of single variables on coliforms. This proved difficult because of
interrelationships among them. For example, as the BOD load to the
secondary ponds increased from September to December 1971, temperatures
87
-------
of wastes within the ponds decreased. Some of the lowest influent BOD
loads were found during June and July 1972. However, during the same
period the ponds had the lowest pHs found during the entire project
(Table I, Appendix).
Extremely high coliform concentrations were found in wastes devoid of
dissolved oxygen (Table 21), but associated with this were extended
storage times and relatively high BOD. Conversely, high D.O. levels
in small scale units appeared to reduce coliform concentrations
(Table 18), but BOD level could not be discounted as a contributing
factor. The highly aerated unit had an average BOD of 91 ppm as
compared to 148 ppm for the unit with normal aeration.
Overshadowing the importance of any other single variable or combination
of variables was the effect of inoculation on the concentrations of
coliforms in secondary wastes. The project mean coliform concentration
for influent samples was considerably greater than for effluent samples
(Table 10). By reducing the number of coliforms going into a small
aerated unit, it was possible to reduce their concentration within the
unit by several orders of magnitude (Table 12).
88
-------
SECTION VIII
ROLE OF COLIFORMS IN BOD REDUCTION
Although coliforms represent less than 2 percent of the total bacterial
population of the secondary treatment ponds (Table 5), it could be
argued that they still are necessary to supply growth factors to other
species or that BOD reducing activity is not related to bacterial
concentration alone. Experiments with the small scale apparatus,
however, showed that good BOD reduction could be obtained without high
concentrations of coliforms During the last two weeks of Experiment 1
(Table 12), good control was maintained over coliform concentrations
in the influent going to experimental unit No. 9. This caused a
corresponding decrease in coliforms within the unit to a mean of 86
thousand/100 ml compared to 10 million/100 ml for the control. Effluent
samples from these units were analyzed for BOD by personnel of Crown
Zellerbach (CZ) and the Environmental Protection Agency (EPA). Mean
BOD values obtained by CZ were 86 ppm for Unit 9 and 69 ppm for Unit
10 (Table 27). This represents a 20 percent higher BOD for the unit
which had lower coliform concentrations. EPA analyses gave mean values
of 60 ppm and 61 ppm for units 9 and 10 respectivelyessentially no
difference. For comparison, mill grab samples taken on November 6 and
8 had BODs of 155 to 183 ppm and coliform concentrations of 20 million
to 21 million per 100 ml.
Coliforms were not completely eliminated in the small experimental
unit but they were reduced to the point which would allow the
89
-------
Table 27. RELATIONSHIP BETWEEN COLIPORM CONCENTRATIONS AND BOD
OF EFFLUENTS FROM SMALL SCALE SYSTEM
Date
(1972)
Oct. 26
Oct. 31
Nov. 6
Nov. 8
Mean
Colif./lOO ml
X 105
Unit #9
0.240
0.029
0.014
0.060
0.086
Unit #10
140
130
120
13
101
Effluent BOD. ppro
Unit #9
C.Z.
100
78
105
60
86
EPA
64
53
67
55
60
Unit #10
C.Z.
76
74
69
57
69
EPA
67
61
60
55
61
Colif.
ratio
#9: #10
0.0017
0.0002
0.0001
0.0046
0.0009
BOD ratio
units 9:10
C.Z.
1.56
1.47
1.57
1.09
1.43
EPA
1.13
1.21
1.15
1.04
1.13
-------
following conclusion. If coliforms have any role in reducing the BOD
of Lebanon wastes it can be satisfied by concentrations of less than
0.1 percent of those now found in the large ponds.
91
-------
SECTION IX
SOURCES OF COLIFORMS
MILL SURVEYS
Several areas within the mill were evaluated as sources of colifonas.
These bacteria were found in drains beneath paper machines but concen-
trations were low and they represented only a small fraction of the
total bacterial population (Table 28). Of much greater importance
were white water systems which utilized recirculated liquids.
Table 28. CONCENTRATIONS OF BACTERIA
IN MILL DRAINS
Source of sample
#1 Paper machine, dry end
#1 Paper machine, wet end
#2 Paper machine, wet end
and pump well
Composite of beater
room drains
Composite of all mill
basement drains
Steam plant plus
mill drains
Bacteria/100 ml
Total
X 10?
__a
5.5
3.2
7.7
1.0
1.2
Colif.
X 105
0.002
0.09
0.02
0.29
0.009
0.005
Colif.,
% of
total
--
0.02
0.006
0.038
0.009
0.004
a -- Not done.
92
-------
RECYCLE SYSTEMS
In the high yield system there are several recycle loops but the most
significant involved the screening bin. This bin receives low
consistency pulp separated from the main mill sewer by a sidehill
3
screen. The bin itself has a capacity of approximately 283 m
(10,000 cubic feet) and can be likened to a continuous growth chamber
with a retention time of about 16 hours. Some of the key features
of the recycle loop are illustrated in Figure 24. The liquid which
is associated with the low consistency pulp is equivalent to primary
influent and has a BOD of approximately 400 ppm. The major source of
BOD is dilute spent sulfite liquor which also supplies ammonia nitrogen.
Temperatures within the bin for most areas are between 20 and 30 C.
and the pH is between 6 and 8. Under these favorable conditions, high
concentrations of coliforms developed. The mean of 15 samples was 90
million coliforms per 100 ml. This represented 5.3 percent of the
total population (Table 29). From the screening bin the pulp goes
back to the mill where it inoculates fresh pulp with coliforms and
contributes to the contamination of other production stages.
The production of regular sulfite pulp does not involve the screening
bin. However, white water used in pulp washing and sluicing is
recirculated (Figure 25) and coliform populations build up. A maximum
of 8 million/100 ml was found in samples from the white water storage
chest (Table 29). During surges, a portion of the white water overflows
to the main sewer and is replaced with fresh make up water. Pulp is
washed for four hours out of every six. Make up water however flows
continuously. This tends to minimize bacterial buildup.
On the basis of coliform concentrations and flow rates, the two systems
described represent major sources of coliforms going to the treatment
ponds.
93
-------
SETTLED ^
WATER /*^~*
PULP
MILL
fe
w
PRI/V1ARY
SIDE HILL
SCREEN
PAPER
PRODUCTS
SCREENING
BIN
LEACHATE ^
MAIN
SEWER
LIQU1DTO
PRIMARY
TREATMENT
Figure 24. Recycle in high yield pulping system.
94
-------
Table 29. CONCENTRATIONS OF BACTERIA IN MILL
WHITE WATER AND TREATMENT SYSTEMS
Source of sample
Regular sulfite white
water storage chest
#3 Reg. sulfite stock chest
Reg. sulfite, unscreened
stock chest
Reg. sulfite knotter
Reg. sulfite decker
Reg. sulfite Cowan screen
Sidehill screen in
screenings bin
Screenings bin,
North side
Screenings bin,
Northwest corner
Screenings bin,
West side
Screenings bin,
Leachate
High yield pulp storage
chest sawdust
High yield pulp storage
chest chips
Main sewer after scr. bin
Secondary influent
Secondary effluent
Date
(1972)
March 23
March 23
Oct. 18
Oct. 18
Oct. 18
Oct. 18
Oct. 18
Oct. 18
March 23
April 13
March 23
Oct. 18
Nov. 6
March 23
March 23
Oct. 18
Nov. 6
March 23
March 23
March 24
March 24
April 13
April 13
Oct. 18
Nov. 6
March 24
April 13
March 24
April 13
March 24
April 13
March 24
April 13
March 24
April 13
Bacteria/100 ml
Total
X 10?
2.3
1.1
2.5
51
0.77
0.08
0.32
2.5
15
6
13
280
210
29
5.5
11
1700
125
47
20
18
10
16
55
7.7
190
10
660
50
13
7.4
180
0.03
50
31
Colif.
X 105
0.19
80
2.8
0.11
4.2
0.044
0.055
2.0
38
,0.1
340
1700
1800
740
220
23
2400
2500
1540
940
260
80
60
900
1.0
20
0.10
40
-:_ 1
50
0.20
4000
_1
340
210
Colif.
% of
total
0.08
73
1.1
0.002
5.5
0.55
0.17
0.80
2.5
^ 0.017
26
6.1
8.6
26
40
2.1
1.4
20
33
47
14
8.0
3.7
16
0.13
0.11
0.01
0.06
*'- 0.02
3.8
0.03
22
<-- 33
6.8
6.8
95
-------
EXCESS
TO
MAIN
SEWER
UNWASHED
PULP
WHITE
WATER
CHEST
WATER
DECKER
1
PULP TO PAPER
MACHINE
STOCK
STORAGE
TEST
Figure 25 Recycle in regular sulfite pulping system.
96
-------
Coliforms enter the mill in the water supply. Although their concen-
trations are low (Table 30) they are a constant source of inoculum
for the growth or recycle systems described.
Table 30. CONCENTRATIONS OF BACTERIA IN
MILL WATER SUPPLY
Date
(1972)
Feb. 1
10
11
March 13
14
15
16
18
22
24
April 13
June 12
13
15
20
28
Oct. 18
Water
temp.,
ฐC.
5.0
4.8
6.0
8.5
7.4
9.0
8.5
7.8
8.5
7.0
8.0
13.4
15.0
14.3
17.3
18.4
12.0
Bacteria/100 ml
Total
X 104
30
200
100
56
48
51
88
24
112
18
30
16
32
13
12
8
11
Coliforms
X 10ฐ
-. 100
240
190
140
450
540
130
200
900
800
230
100
100
20
50
'.. 10
1000
Colif.,
% of
total
-'' 0.03
0.01
0.02
0.02
0.09
0.11
0.01
0.08
0.08
0.44
0.08
0.06
0.03
0.02
0.04
< 0.01
0.91
SANITARY WASTES
Tests also were made to determine if sanitary wastes were reaching the
mill waste system. Rhodamine B dye was added to seven toilets which
were flushed separately. Influent to the city treatment system was
then monitored. Presence of the dye was considered to be positive
evidence that sanitary waste from that source was not entering the
mill waste treatment facility. This was a more satisfactory method
than looking for the tracer in the mill waste. Here, negative results
97
-------
were inconclusive because of effluent masking effects and/or reactions
with the dye. The tracer was found in only five trials. Breaks were
located in lines from the two suspect toilets and it was found that
wastes were being channeled to the primary pond sidehill screen. The
toilets were barred from use until the defective lines were replaced
on April 27. Elimination of these sources of coliforms did not reduce
coliform concentrations in secondary influent or effluent (Tables I
and II, Appendix).
98
-------
SECTION X
ACTIVITY OF CHLORINE IN SECONDARY WASTES
INITIAL EVALUATION OF BACTERICIDAL ACTIVITY
Preliminary laboratory trials showed that 5 to 10 ppm chlorine in
secondary effluent would greatly reduce coliform concentrations within
10 minutes. Similar activity was found in initial mill trials. Tests
made on September 28, 1971, showed that 7 ppm chlorine killed 99.997
percent of the coliforms within 60 minutes (Table 31).
Table 31. EFFECT OF TIME ON DESTRUCTION OF BACTERIA BY CHLORINE.
MILL TRIAL OF SEPT. 28 WITH 7 PPM CL.
Reaction
time
0
1 Minute
5 Minutes
10 Minutes
30 Minutes
1 Hour
16 Hours
Bacteri;
X
Total
49,000
5,200
6,100
5,700
1,600
300
8,400
j/100 ml
^ฐ
Colif .
33
1.6
0.13
0.029
0.004
0.001
0.001
Number of bact.
killed/100 ml
X 105
Total
0
43,800
42,900
43,300
47,400
48 , 700
40,600
Colif.
0
31.40
32.87
32.97
33.00
33.00
33.00
7. of Initial
population killed
Total
0
89.388
87.551
88.367
96.735
99.388
82.857
Colif.
0
95.152
99.606
99.912
99.988
99.997
99.997
Action was rapid with over 95 percent kill in 1 minute. There also
was significant reduction in the total bacterial population during the
same period. There was some regrowth of the total population, but not
of coliforms, between 1 and 16 hours after chlorination.
99
-------
In another mill trial reaction times were kept at 10 minutes and the
rate of chlorination was varied. Bactericidal activity was apparent
at 5.3 ppm but 8.9-10.8 ppm were required for adequate coliform kill
(Table 32).
Table 32. EFFECT OF CHLORINE CONCENTRATION ON DESTRUCTION
OF BACTERIA. MILL TRIAL OF SEPT. 29.
Chlorine
cone. ,
ppm
0
5.3
7.0
8.9
10.8
Bact./lOO ml
after 10 minutes
X 105
Total
15,000
4,800
5,400
6,400
4,100
Colif .
49.0
21.0
7.40
0.81
0.001
Number of bact.
killed/ 100 ml
X 105
Total
0
10,200
9,600
8,600
10,900
Colif.
0
28.00
41.60
48.19
49.00
% of Initial
population killed
Total
0
68.000
64.000
57.333
72.667
Colif.
0
57.143
84.898
98.347
99.998
A large segment of the total population also was killed. Coliform
data shown in Table 32 was obtained by the membrane filter method.
The multiple tube presumptive test gave slightly higher results but
also indicated that a chlorine concentration between 8.9 and 10.8 ppm
was effective against coliforms (Figure 26).
Laboratory tests showed that chlorine reacts rapidly with Lebanon
secondary effluent and the amount taken up within 5 minutes was
proportional to that added, over a wide range of concentrations. This
is illustrated in Figure 27. From the curve it would be difficult to
assign a conventional chlorine demand value to the effluent as there
is no sharp break between 2 and 40 ppm of added chlorine. In other
tests the addition of 500 ppm chlorine to effluent resulted in residuals
of 1 to 5 ppir after a 60 minute contact time. This indicates a chlorine
demand of approximately 500 ppm which is many times greater than
bactericidal concentrations.
100
-------
lO-i
a:
o
<
CQ
Oi
o
6-
4-
2-
0
M1LL TRIAL OF 9/29/71
lOmin. REACTION TI/V1E
A/I F. COL I FORMS3
PRES. MT COLIFORMS3
O O TOTAL BACTERIA3
5.3 7
CHLORINE CONC.. ppm
8.9
10.8
Figure 26. Bactericidal activity of chlorine in secondary effluent.
3See Apparatus and Methods.
101
-------
40
E
ex
o.
MILL EFFLUENT OF 11/17/72
5 minute CONTACT TIME
<
Q_
25
31
O
10
10 20
CHLORINE ADDED, ppm
40
Figure 27. Chlorine uptake by secondary effluent.
Laboratory chlorination.
102
-------
EFFECT OF DILUTION
Secondary effluent is discharged into Mark Slough where it may be
diluted by as much as 50 percent by water spilling over a dam above
the slough. This suggested that chlorine treatments which were
effective against coliforms in undiluted effluent might not be adequate
when the effluent, and consequently the chlorine, were diluted. To
evaluate the possibility, effluent was chlorinated at a rate of 9.1 ppm.
A chlorinated sample was collected at the outfall to the slough. A
portion of the sample was immediately diluted with an equal volume of
water taken upstream from the outfall. The diluted and undiluted
samples were incubated at 20 C. and analyzed at intervals for bacteria.
It was found that coliform concentrations decreased at approximately
the same rates in dilute and non-diluted chlorinated effluent samples
(Figure 28). As in previous tests, approximately 90 percent of the
coliform populations were killed within the first minute (Table 33).
There was no significant regrowth of coliforms within 24 hours of
chlorination.
Results from these initial experiments indicated that coliforms in
secondary effluent could be controlled under existing field conditions
by the addition of approximately 10 ppm chlorine. In succeeding
trials, however, it became apparent that this was not a reliable
method. On December 23 and 27, chlorine concentrations of 5 to 10 ppm
were effective against coliforms but on the 14th, 15th, and 23rd,
there was little or no activity at 9.0 to 15.0 ppm (Table 34). These
variations in performance initiated a study to determine the effect
of variables on chlorine activity.
METHODS FOR EVALUATING CHLORINE ACTIVITY
Three rapid methods were developed for estimating chlorine activity.
They made it possible to analyze many more samples in a given time
than could be done by conventional methods of coliform analysis.
103
-------
8
CO
CD
o
2-
INITIALCICONC.-9.lppm
CHLORINATED EFFLUENT-NO DILUTION
CHLORINATED EFFLUENT-DILUTED 50-50
0
10
20
30 40 50
REACT I ON TIME, minutes
60
70
80
Figure 28. Effect of dilution on chlorine activity.
-------
Table 33. EFFECT OF DILUTION ON THE BACTERICIDAL ACTIVITY OF CHLORINE IN SECONDARY EFFLUENT.
MILL TRIAL OF 10-26-71 WITH 9.1 ppm INITIAL CHLORINE
React.
time,
tnins.
0
1
5
10
20
40
80
160
320
24 Hrs.
Colif ./100 ml
X 105
Undil.
eff.
320
22
3.9
1.2
0.32
0.037
0.008
0.011
0.006
0.006
Eff.
clil.
1:2
99
9.4
2.0
0.74
0.18
0.081
0.019
0.007
0.003
0.008
Conforms killed
Cells/100 ml X 10>
Undil.
eff
0
298
316
319
319+
319+
319+
319+
319+
319+
Eff.
dil.
1:2
0
90
97
98
98+
98+
98+
98+
98+
98+
Percent
Undil.
eff.
0
93.125
98.781
99.625
99.900
99.988
99.998
99.997
99.998
99.998
Eff.
dil.
1:2
0
90.505
97.980
99.253
98.818
99.982
99.981
99.993
99.997
99.992
Total bact.
per 100 ml X 107
Undil.
eff.
220
160
250
170
180
120
64
33
30
170
Eff.
dil.
1:2
210
220
130
110
98
64
42
28
40
100
Total bacteria killed
Cells/100 ml X 10'
Undil.
eff.
0
60
0
50
40
100
156
187
140
50
Eff.
dtl.
1:2
0
0
80
100
112
146
168
182
170
110
Percent
Undil.
eff.
0
27.273
0
22.727
18.182
45.454
70.909
85.000
63.636
22.727
Eff.
dil.
1:2
0
0
38.095
47.619
53.333
69.524
80.000
86.667
80.952
52.381
-------
Table 34. EFFECTIVENESS OF MILL CHLORINATION SYSTEM
Date
(1971)
Dec. 14
Dec. 15
Dec. 23
Dec. 27
Dec. 31
Ci
cone . ,
ppro
0
9.0
9.0
9.0
9.0
0
3.0
5.0
7.0
9.0
11.0
13.1
15.0
0
2.7
4.6
10.5
15.0
0
5.0
10.0
0
7.8
12.4
Reaction
time (min.)
0
1
5
10
20
0
10
10
10
10
10
10
10
0
30
30
30
30
0
30
30
0
30
30
Colif ./100 ml
X 105
16
13
16
18
14
50
60
100
80
50
50
40
40
104
51
58
^0.1
^ 0.001
54
r 0.1
99. 904
799.999
0
< 99. 815
7*99.998
0
22.222
27.778
106
-------
Perhaps of greater importance, cause and effect could be related in a
very short interval of time. The methods proved to be very useful in
evaluating the effects of variables on chlorine activity and for
monitoring full scale chlorination of effluent.
Motility Test
Secondary effluent consistently contained motile spirilla (Figure 9).
The concentrations of chlorine required to stop their motility was
found to correlate well with those required to reduce coliforms to
acceptable levels (Table 35). To carry out the test, chlorine was
allowed to react for the desired length of time, then was inactivated
with sodium thiosulfate. The concentration of motile spirilla remaining
was estimated by examining the sample microscopically with phase
contrast and 400 magnification. When motile spirilla were present, 20
fields were examined and the number per field estimated. If no motility
was found within 20 fields an additional 80 fields were examined. If
no motile spirilla were seen, their concentration was assumed to be 0
per field.
Inhibition of Oxygen Uptake
As microorganisms utilize various compounds in secondary wastes they
consume approximately 2 ppm of oxygen per hour. Rates will vary
depending on concentrations of substrates, oxygen, .and microorganisms.
The amounts of chlorine required to inhibit the rate of oxygen uptake,
by 64 percent or more were similar to those required to kill coliforms
(Table 35). The test was performed by transferring mechanically
aerated effluents to BOD bottles and then measuring D.O. concentrations
at intervals. A D.O. meter equipped with a stirring BOD probe was
used for this purpose.
107
-------
TnMc 35. OWPAltlSON OF M2THODJ FOR EVALUATING CHLGRIM ACTIVITY. OXYGEN UPTAKE, BACTERIAL HOTIUTY AND MEMBRANE FILTER
/!ill
trlnl
it nt i1
(1971)
Dec.
23
Dec .
27
Dec.
31
Cl
crmc ,
PDIT
0
2.7
4.6
10.0
15.0
0
5.0
10.0
0
4.0
6.0
7.8
9.7
12.0
12.0
15.0
Oxygen uptake tett
Dlปปolved oxyiien.
Ini.
9.C
9.8
9.8
9.6
9.5
10.3
10 0
10.0
1
Hr
7.0
6.8
6.7
7.3
8.5
7.4
7 9
9.0
?
Hr
4.8
4.7
4.4
6.3
r-8'1
5.0
--
3
Hr
2.4
2.7
2.2
5.1
7.8
2.6
5 2
7.7
3pm
4
Hr
0.7
0.7
0.5
4.0
7.5
0.4
2.7
6.9
24
Hr
0.7
0.5
0.4
0.4
__
0.2
0.2
2.1
Inhlb of 0? uptake. I
\
Hr
0
31
0
22
64
0
28
65
2
Hr
0
0
0
34
72
0
3
Hr
0
4
0
58
77
0 '
37
70
4
1 Hr
0
0
0
38
78
" NuJ*er per field et 400 X eagnlfleetIon.
-------
5 Minute Residuals
When sodium hypochlorite was used as the chlorinating agent, positive
3
tests for total residual chlorine after a 5 minute contact time
generally indicated that bactericidal concentrations of chlorine had
been reached in secondary effluent (Table 36). Other forms of chlorine
and the presence of nitrite in effluent however, gave false positive
reactions.
FACTORS AFFECTING CHLORINE ACTIVITY IN LABORATORY TESTS
Portions of a secondary effluent sample were adjusted to pH 5.0 with
H-SO, ; to pH 9.0 with NaOH and left unchanged at pH 7.0. Various
amounts of sodium hypochlorite were added and the effects on micro-
organisms were determined by measuring the inhibition of oxygen uptake
and by observing the effect on bacterial motility.
Oxygen Uptake -- D.O. measurements were made hourly for the first four
hours of the test then again after 18 hours. An extrapolation of D.O.
vs time curves (Figure 29) show that oxygen would have been depleted
in the controls within 4.8 to 6.7 hours depending on pH. Uptake was
most rapid at pH 9 and slowest at pH 5. Chlorine was inhibitory at
all concentrations tested between 4 and 16 ppm (Table 37) but the
degree and persistence of activity varied with effluent pH.
At pH 5, 4 ppm Cl increased the time required for oxygen depletion
from 6.7 hours to 9.3 hours. Higher concentrations of chlorine
prevented depletion for the entire 18 hour period. A characteristic
of chlorine at pH 5 was the marked increase in activity as concentra-
tions were increased. Results were similar at pH 7 but here there was
not as much difference in activity between 8 and 16 ppm chlorine as
there was at pH 5.
109
-------
Table 36. COMPARISON OF METHODS FOR EVALUATING CHLORINE ACTIVITY.
CHLORINE RESIDUAL. BACTERIAL MOTILITY. MEMBRANE FILTER AND MULTIPLE TUBE
Date
(1972)
March 16
March 17
Cl
added,
ppm
0
4.6
6.0
8.0
10.0
10.0
12.5
12.8
20.5
26.0
0
4.0
6.0
8.0
10.0
22.2
21.2
Method
of
chlorination
Laboratory
with
NaOCl
Mill with
ciz
Laboratory
with
NaOCl
Mill with
C12
5 Min
Cl
resid
0
0
0
+
+
0
0
0
0
+
0
0
0
+
+
0
0
Motile
spirilla
@ 30 min
1-10
0.1-1
0.01-0.1
0
0
0.1-1
0.1-1
0.1-1
0.01-0.1
0.01-0.1
1-10
0.1-1
0.01-0.1
0
0
0.01-1
0.1-1
Colif/100 ml
X 10 @ 30 min
M.F.
200
0.009
0.038
100
60
90
30
0.037
250
0.40
0.05
0.30
0.50
7.7
30
M.T.
140
0.014
0,021
80
90
50
540
1.7
130
0.30
0.02
1.7
0,02
17
8
Coliform
reduction, %
M.F.
__a
99.996
99.981
40.000
10.000
70.000
99.963
99.840
99.980
99.880
99.800
96.920
88,000
M.T.
99.990
99.985
0
37.500
0
97.875
99.769
99.985
98.692
99 ซ 985
86.923
93.846
a -- Not determined.
-------
01
TIME, hours
Figure 29. Effect of chlorine on oxygen uptake by
secondary effluent at various pHs.
ฉ=OppmCI; A=4ppmCI; O=8ppmCI;
in
-------
Table 37. EFFECT OF pH AND CHLORINE ON OXYGEN UPTAKE DY SECONDARY EFFUiiiHT AND (jN BACTERIAL MOTILITY
Effluent
pซ
Inl
5.0
7.0
9.0
Fin
5.0
5.2
5.3
5.4
6.)
6.6
6.8
6.8
9.0
9.0
8.9
8.9
Cl
added
ppm
0
4.0
8.0
16.0
0
4.0
8.0
16.0
0
4.0
8.0
16.0
Dissolved oxygen, ppm
after:
Inl
8.8
8.9
8.8
8.9
8.9
a. 7
8.9
9.0
8.9
8.7
8.5
1
Hr
7.6
8.1
8.6
8,7
6.9
7.8
8.2
8.5
5.9
7.2
7.6
2
Hr
6.2
7.2
8.0
8.5
5.1
6.8
8.1
8.5
4.0
6.6
7.2
3
Hr
5.0
6.2
7.7
8.4
3.4
6.0
7.7
8.3
1.8
6.2
6.7
4
Hr
3.7
5.1
7.2
8.5
1.5
5.1
7.6
8.3
0.5
5.6
6.5
18
Hr 1
0.5
0.3
3.6
7.6
0.4
0.4
5.3
7.6
0.3
2.7
5.0
Inhibition of D.l>.
uptake. 1. after:
1
Hr
0
38
84
84
0
55
65
75
0
50
63
70
2
Hr
0
38
69
85
0
50
79
87
0
57
67
74
3
Hr
0
29
71
87
0
51
78
87
0
65
72
75
4
Hr
0
25
69
92
0
51
82
90
0
63
74
76
18
Hr
0
0
38
84
0
2
58
84
0
30
56
59
Motile spirilla/field
after:
5
Mln
1-10
1-10
0
0
1-10
1-10
1-10
0
1-10
1-10
1-10
1-10
10
Min
1-10
1-10
0
0
1-10
1-10
0.01-0.1
0
I- 10
1-10
1-10
0.01-0.1
15
Mln
1-10
0.01-0.1
0.01-0.1
0
1-10
1-10
0.01-0.1
0
I- 10
1-10
1-10
0.01-0.1
30
Min
1-10
0.01-0.1
0
0
1-10
1-10
0.01-0.1
0
1-10
1-10
0.1-0.1
0
4
Hr
1-10
0.01-0.1
0
0
1-1C
1-10
0
0
1-10
0.01-0.1
0
c
16
Hr
1-10
0.01-0.1
C.01-C.1
G
1-10
1-10
0.01-0.1
C. 01-0.1
0.01-C.l
0
0
0
' -- Mot dซtซrปlnซd.
-------
The behavior of chlorine at pH 9 differed in three respects from that
at the lower pHs.
1. Oxygen depletion was prevented for 18 hours by 4 ppm chlorine, a
concentration which was ineffective at lower pHs.
2. Differences in the amounts of chlorine added to effluent had less
effect on the rate of oxygen uptake than was found at lower pHs. At
pH 9, oxygen uptake curves in the presence of 8 ppm and 16 ppm of
added chlorine were almost superimposable.
3. The highest concentration of chlorine tested, 16 ppm, was less
effective at pH 9 than at the lower pHs.
The data are presented differently in Figure 30 to show how the effect
of pH on chlorine activity differs according to chlorine concentration.
Considering first 4 ppm, there was inhibition at pH 5-9 but not enough
to consistently meet the critereon of 64 percent inhibition of oxygen
uptake (Table 37). At the lower pHs chlorine activity did not persist
but at pH 9 it was still apparent after 18 hours. Concentrations of
8 and 16 ppm chlorine, at PH 5, 7 and 9, inhibited oxygen uptake by
64 percent or more, meeting the critereon for effective chlorination.
At these higher addition rates activity persisted for at least 18 hours
at all pHs.
The results show that low pH effluent favors rapid chlorine activity
and limited stability. The reverse occurs at high pH. The intensity
or level of chlorine activity is not great in high PH effluent but it
remains for a considerable time.
113
-------
8
6
4
2 J
E
Q
Q
d
NO CHLORINE
4ppm Cl
_L_J
8
6
4
2
SppmCI
1234
8
12
1234
8
TIME, hours
Figure 30. Effect of pH on inhibition of 0? uptake by chlorine.
0= pH 5; O= pH 7; i= pH 9.
12
-------
The optimum combination of pH and chlorine concentration would provide
enough time and activity to kill coliforms in effluent and enough
chemical reactivity to be consumed before the treated effluent reaches
receiving waters.
Motility -- Results from motility tests also showed that pH had a
significant effect on the rate of chlorine activity (Table 37). For
example, 8 ppm chlorine stopped bacterial motility within 5 minutes
when the effluent pH was 5.0. As the pH was increased more time was
required. At pH 7 more than 30 minutes were necessary and at pH 9
motility was stopped only after a reaction time of more than 4 hours.
Only at pH 9 was 4 ppm chlorine effective but it required from 4 to 18
hours.
Conclusions based on these results are the same as those from oxygen
uptake tests. Low effluent pH favors rapid activity and limited
stability; high pH favors the reverse.
Chlorine Residuals In these tests, chlorine addition rates were
related to activity at various pHs. No analyses were made to determine
the actual concentrations of chlorine in the effluent.
In another experiment, sodium hypochlorite was added to secondary
effluent samples, adjusted to pH 1.7 to 9.0, to provide initial
chlorine concentrations of 10 ppm. Analyses showed that samples with
pHs in the range of 5 to 9 contained 2.6 ppm total residual chlorine
after 30 seconds (Table 38). After 1 hour, residuals were 1.3 ppm at
pH 9 and 0.4 ppm at pH 7. No residuals could be found at pH 5 or
below. On the basis of these results and those from the previous tests,
the following conclusions can be drawn:
115
-------
Table 38. EFFECT OF pH ON TOTAL CHLORINE RESIDUALS IN SECONDARY EFFLUENT.
APPLICATION RATE 10 PPM.
Eff.
pH
1.70
2.90
5.00
6.95
9.00
Total resid. Cl, ppm after:
30 sec
0
0.90
2.60
2.60
2.60
1 min
0
0.90
__a
--
2.60
2 min
0
0.90
1.70
2.20
2.60
5 min
0
0.40
1.70
1.30
2.20
30 min
0
0.40
0.40
0.40
1.30
1 hr
0
0
0
0.40
1.30
% of Added Cl remainin
30 sec
0
9.0
26
26
26
1 min
0
9.0
--
--
26
2 min
0
9.0
17
22
26
5 min
0
4.0
17
13
22
E after:
30 min
0
4.0
4.0
4.0
13
1 hr
0
0
0
4.0
13
a -- Not determined.
-------
a. Chlorine reacts rapidly with constituents of secondary effluent.
b. The percent of added chlorine remaining increases as effluent pH is
increased.
c. At equal or lower concentrations, chlorine is more bactericidal at
pH 5 and 7 than at pH 9.
In the preceeding experiment it was found that no chlorine residual
could be detected when 10 ppm chlorine were added to effluent which
had been adjusted to pH 1.7 (Table 38). The low pH was tested to
simulate the reaction near the chlorine-effluent interface during mill
chlorination. Here gaseous chlorine is used and its hydrolysis produces
low pH solutions by the following reaction:
C12 + H20 ปHC1 + HOC1
The pH of mill chlorinating solutions and of mixtures with effluent,
near the point of contact, would be in the range of 1-2. Further
testing showed that over 19 ppm chlorine were required to produce a
5 minute chlorine residual in pH 1.7 effluent (Table 39).
Table 39. CHLORINE REQUIRED TO PRODUCE 5 MINUTE
RESIDUALSaIN EFFLUENT AT pH 1.7 AND 7.0
Cl
added
ppm
3.8
5.8
9.6
11.5
14.4
19.3
24.0
28.8
34.6
5 Minute chlorine residual3
ppm
pH 1.7
0
0
0
0
0
0.9
1.8
3.1
2.2
pH 7.0
1.3
1.8
2.2
3.5
4.9
--b
--
--
% of A
pH 1.7
0
0
0
0
0
5
7
11
6
dded Cl
pH 7.0
34
31
23
30
34
*
" *
-- Not determined.
117
-------
With pH 7 effluent, 3.8 ppm or less were needed. At the relatively
high chlorination rate of 50 ppm, 87 percent reacted with effluent
within 30 seconds at pH 1.6 but only 38 percent reacted at pH 7
(Table 40). Under the test conditions, volatilization of chlorine from
a dilute control solution of H SO at pH 1.6 was only 2.6 percent.
Table 40. EFFECT OF pH ON CHLORINE UPTAKE BY SECONDARY EFFLUENT.
APPLICATION RATE 50 ppm.
Sample
Effluent la
Ib
Ave.
Effluent 2a
2b
Ave.
Effluent 3a
3b
Ave.
Effluent 4a
4b
Ave.
Dilute H2S04
Dilute NaOH
PH
after
chlor .
1.6
1.6
1.6
3.0
3.0
3.0
7.2
7.2
7.2
8.4
8.4
8.4
1.6
8.7
Cl resid.
after 30 sec.
ppm
7.1
5.3
6.2
31.9
32.3
32.1
31.0
30.6
30.8
30.1
28.4
29.2
48.7
49.6
Corrected chlorine
uptake
ppm
41.6
43.4
42.5
17.7
17.3
17.5
18.6
19.0
18.8
19.5
21.2
20.4
1.3
0.4
% of Added
85.4
89.1
87.3
35.7
34.9
35.3
37.5
38.3
37.9
39.3
42.7
41.1
2.6
0.8
These experiments have shown that reactions between chlorine and
secondary effluent are very rapid and complete at pH 1-2. However, the
tests were made by adding high pH chlorinating solutions to low pH
effluent. In practice, when chlorine gas is used, low pH chlorinating
solutions are added to neutral effluent. Evaluation of pH effects on
chlorine reactivity was extended to include this condition as well as
118
-------
other combinations of effluent pH and chlorinating solution pH. Results
are shown in Table 41 and Figure 31.
Considering first the addition of chlorine to effluent with a normal
pH of 7.2, it was found that as the pH of the chlorinating solution
was increased, less chlorine was required to provide a 5 minute residual
and higher percentages of added chlorine were recovered (Table 41).
For example, when the pH of the chlorinating solution was 2.8, a
chlorine application rate of 9.8 ppm was required to produce a 5
minute residual and recovery was only 4.4 percent. In contrast, a
chlorinating solution with a pH of 10.6 produced a 5 minute residual
at an application rate of only 4 ppm chlorine. Recovery averaged 30
percent when the applied rate was in the range of 4 to 10 ppm. Chlorine
solutions closer to neutrality gave intermediate results.
The pH of chlorinating solutions influences the following types of
reactions which in turn affect the chlorination process:
1. Equilibrium reactions involving chlorine^ As shown in Figure 32
the species of chlorine in solution is determined by pH. For example,
at pHs between 1 and 2 there are high concentrations of molecular
chlorine (Cl ); at pH 5 chlorine is present as hypochlorous acid (HOC1)
only; above PH 5 ionization of HOC1 begins and at pH 9 most of the
chlorine is in the form of hypochlorite ions (OC1~).
2. Ionization. The pH of mixtures of chlorine and effluent, near the
point of contact, will be influenced by the pH of the chlorinating
solution. This in turn may affect the ionization of compounds in the
effluent. For example at low pHs the ionization of lignosulfonic
acids would be repressed and that of ammonia would be enhanced. With
high pH chlorinating solutions the reverse would occur.
119
-------
Table 41. EFFECT OF CHLORINATING SOLUTION pH AND EFFLUENT
pH ON CHLORINE RESIDUALS IN SECONDARY EFFLUENT
PH
Cl,
soln.
2.8
4.4
6.8
10.6
12.0
2.0
Eff.
7.2
7.2
7.2
7.2
11.0
10.2
Mixt.
7.2
7.0
6.8
6.7
6.5
7.3
7.3
7.3
7.2
7.2
7.6
7.6
7.4
7.4
7.4
7.2
7.5
7.4
7.4
7.4
11.2
11.3
11.3
11.3
11.3
9.8
9.8
9.7
9.6
9.5
Cl
added
ppm
2.0
3.9
5.8
7.8
9.8
1.9
3.9
5.8
7.7
9.6
2.0
3.9
5.9
7.8
9.8
2.0
4.0
5.9
7.9
9.9
1.9
3.9
5.8
7.8
9.7
5.3
7.1
8.9
10.7
12.4
5 Min.
chlorine
res id., ppm
0
0
0
0
0.43
0
0
1.2
1.3
2.2
0
0.43
0.86
1.72
1.72
0
0.86
1.72
2.84
3.18
2.84
3.44
5.15
6.00
8.60
1.72
1.72
1.72
1.72
1.72
Cl recovered,
% of
added Cl
0
0
0
0
4.4
0
0
21
17
23
0
11
15
22
18
0
22
29
36
32
100
88
89
77
89
32
24
19
16
14
120
-------
E
o.
O.
O
00
a:
o
IE
o
cu
4'
0
6 8
CHLORINE ADDED, ppm
10
Figure 31 Relationships between applied chlorine and 5 minute residuals
in secondary effluent. Effect of pH.
-------
100-
c
0?
0>
o.
o
to
o
UJ
Q_
C/)
or
3
o
20 -
0
Figure 32. Relationship between pH and chlorine species in 0.1 N solutions ,8
-------
3. Monochloramine formation. The rate of monochloramine (NH9C1)
9
formation is highly dependent upon pH. In dilute solutions, at pH 2,
reactions require 421 seconds for 99 percent completion. At pH 8.3
the reaction time again is only 0.07 seconds. At higher pHs the
reaction rate is again slower. Lebanon secondary effluent contains
over 100 ppm ammonia nitrogen and NH9C1 has been detected in effluent
treated with 12 ppm chlorine added as NaOCl (See Section XII).
The effectiveness of a chlorination process may well depend upon the
rates at which the three reactions occur.
When the pH within the reaction zone is about 2, molecular chlorine
reacts rapidly with lignosulfonic acids and may be completely
inactivated before complete mixing can occur.
At pH 7, HOC1 and OC1~ will react more slowly with lignosulfonate ions
and there is a possibility for NH_C1 formation. Monochloramine has
bactericidal activity and may react with lignosulfonates at a relatively
slow rate. In this situation complete mixing would be expected before
the inactivation of chlorine.
If the pH in the immediate reaction zone is about 10 the rate of
reaction between OC1~ and lignosulfonates will be very slow leading
to complete mixing before significant inactivation of chlorine.
Formation of NH^Cl may take place at some stage prior to complete
mixing where the pH of the mixture is between that of the chlorinating
solution and effluent and optimum for NH^Cl formation.
In the extreme condition, where a high pH chlorinating solution (pH 12)
was added to a high pH effluent (pH 11), a 5 minute residual was
produced with 2 ppm added chlorine and recovery was approximately 90
percent. In this situation chlorine exists as OC1 and reactions
with ionized lignosulfonates and with NH~ to form NH2C1 will be slow.
123
-------
Complete mixing can occur before much chlorine reacts. In the mixture,
reactions will continue slowly not only because chlorine will still be
present mostly as OC1 but its concentration will be low because of
dilution.
Chlorine Concentration
Reaction rates between chlorine and secondary effluent were measured
at pH 1.7 and 7,0. Chlorine was added in the form of sodium hypochlorite,
Two chlorine concentrations were tested at each pH, the minimum
required to provide a 5 minute residual and twice that concentration.
At pH 7.0 the minimum chlorine level was 5.8 ppm compared to 24.0 ppm
at pH 1.7. At these concentrations, reaction rates during the first
5 seconds were equivalent to 1730 ppm/hr at pH 7 and 15,400 ppm/hr at
pH 1.7 (Table 42). Doubling the chlorine addition increased initial
reaction rates by 58 percent at PH 7.0 and by 92 percent at pH 1.7.
After the first 5 seconds, rates greatly decreased and within 60 seconds
were similar regardless of initial chlorine concentration and pH
(Figure 33). With minimal chlorine levels, residuals were not detected
after 3 hours. With higher levels of application, residuals persisted
for more than 3 hours (Figure 34).
Results showed that effluent pH determined the amount of chlorine
required to produce a chlorine residual. In practice the pH of the
chlorinating solutions would determine the concentration required.
Increasing the amount of chlorine added to effluent increased reaction
rates but also led to increased levels of residual chlorine which
persisted for more than 3 hours. This would not be desirable in full
scale operation. Here, an optimum concentration would be that which
would significantly reduce coliform populations in effluent and leave
no residual after a contact time equivalent to the passage of effluent
to receiving waters. In this case, approximately 4 to 6 hours.
124
-------
4 _
QL
CX.
O
rI
o
o
3 -
2 -
Q_
O
1 _
0
INITIAL
CHLORINE, ppm
-J- I ป _JL
10 15 50
REACT ION TIME, seconds
Figure 33. Effect of pH and initial chlorine concentration on reaction rates of chlorine
with secondary effluent.
-------
Table 42. EFFECT OF CHLORINE CONCENTRATION ON REACTION RATES
Eff.
PH
7r\
. V
Cl
added ,
ppm
5.8
11.6
Elapsed
time
5 Sees
10 Sees
15 Sees
30 Sees
60 Sees
2 Mins
5 Mins
30 Mins
60 Mins
2 Hrs
3 Hrs
4 Hrs
5 Sees
10 Sees
15 Sees
30 Sees
60 Sees
2 Mins
5 Mins
30 Mins
60 Mins
2 Hrs
3 Hrs
4 Hrs
Cl
resid . ,
ppm
3.4
3.0
3.0
2.6
2.6
2.2
1.7
0.43
0.43
0.43
0
0
7.8
7.3
7.3
6.5
6.0
5.6
5.2
3.0
2.2
1.7
0.86
0
Cl uptake
during react.
int. ppm
2.4
0.4
0
0.4
0
0.4
0.5
1.3
0
0
0.43
0
3.8
0.50
0
0.80
0.50
0.40
0.40
2.2
0.80
0.50
0.84
0.86
Duration
of react.
interval
5 Sees
5 Sees
5 Sees
15 Sees
30 Sees
1 Min
3 Min
25 Mins
30 Mins
1 Hr
1 Hr
1 Hr
5 Sees
5 Sees
5 Sees
15 Sees
30 Sees
1 Min
3 Mins
25 Mins
30 Mins
1 Hr
1 Hr
1 Hr
Cl uptake,
ppm/hr
1730
288
0
96
0
24
10
3
0
0
0.43
0
2740
360
0
190
60
24
8
5
2
0.5
0.8
0.9
126
-------
Table 42 (continued). EFFECT OF CHLORINE CONCENTRATION
ON REACTION RATES
Eff .
pH
1.7
Cl
added ,
ppm
24
48
Elapsed
time
5 Sees
10 Sees
15 Sees
30 Sees
60 Sees
2 Mins
5 Mins
30 Mins
60 Mins
2 Hrs
3 Hrs
4 Hrs
5 Sees
10 Sees
15 Sees
30 Sees
60 Sees
2 Mins
5 Mins
30 Mins
60 Mins
2 Hrs
3 Hrs
4 Hrs
Cl
resid. ,
ppm
2.6
2.6
2.2
2.2
1.3
1.3
0.86
0.43
0
0
0
0
6.9
6.5
5.6
5.2
4.7
4.3
--a
2.6
2.2
0.86
0.86
0.43
Cl uptake
during react.
int. ppm
21.4
0
0.40
0
0.90
0
0.44
0.43
0.43
0
0
0
41.1
0.40
0.90
0.40
0.50
0.40
--
1.7
0.40
1.3
0
0.43
Duration
of react.
interval
5 Sees
5 Sees
5 Sees
15 Sees
30 Sees
1 Min
3 Mins
25 Mins
30 Mins
1 Hr
1 Hr
1 Hr
5 Sees
5 Sees
5 Sees
15 Sees
30 Sees
1 Min
.
28 Mins
30 Mins
1 Hr
1 Hr
1 Hr
Cl uptake,
oom/hr
15,400
0
288
0
108
0
9
1
0.9
0
0
0
29,600
288
650
96
60
24
*
4
0.8
1
0
0.4
a -- Not determined.
127
-------
ro
oo
E
Q.
OL
ID
O
CO
LU
o:
O
INITIAL
CHLORINE, ppm
5.8
11.6
24.0
48.0
0
30 60 120
REACTION TIME, minutes
Figure 34. Effect of pH on disappearance of chlorine residuals in
secondary effluent.
-------
Dissolved Oxygen
Several conditions could lead to low D.O. concentrations or depletion
of oxygen in wastes within the secondary ponds. These include aerator
failure, accumulation of sludge beds and overloading. In these
situations, bacteria could produce compounds which have a rapid demand
for chlorine, e.g., SO ~, S and aldehydes, thereby increasing the
Bacteriological Chlorine Demand. The effect of anaerobic growth
conditions on chlorine demand was investigated in a laboratory
experiment. Under the most drastic conditions, 3 days of anaerobic
incubation, bacterial motility was not completely stopped by 10.4 ppm
of added chlorine. In contrast, only 5.2 to 6.2 ppm were required for
the mildest treatment (Table 43). This was a sample which had been
refrigerated overnight then aerated before testing. The results
showed that anaerobic conditions in secondary wastes can lead to
increased chlorine requirements.
Sulfite
During secondary treatment there is a reduction in the concentration
of compounds which react with chlorine. An example is shown in
Table 44. In this test, waste samples were diluted 1:10 in order to
obtain excess chlorine with application rates similar to those used
in practice. Chlorine uptake for diluted influent samples was 19
and 26 ppm compared to 7 and 9 ppm for diluted effluent. Sulfite
accounted for 90 and 48 percent of the total chlorine uptake in the
two influent samples. According to the following equation 0.89 ppm
chlorine reacts with 1 ppm sulfite:
C12 + S03= + H20 >S04= + 2C1" + 2H+
This reaction is very important with respect to chlorine requirements
of secondary influent. Under normal conditions sulfite concentrations
are reduced to low levels during secondary treatment and reactions
129
-------
Table 43. EFFECT OF ANAEROBIC INCUBATION
ON CHLORINE ACTIVITY
Sample
#
1
2
3
4
5
Pre-chlorlnation treatment
Refrigerated overnight
then tested at 20ฐ C.
Same as 1 but aerated
before chlorinating
Incubated anaerobically
for 16 hrs. at 20ฐ C.
Same as 3 but aerated to
a D.O. cone, of 9.1 ppm
Incubated anaerobically
for 3 days at 20ฐ C.
Cl
added,
ppm
0
5.2
6.2
8.3
10.4
5.2
6.2
8.3
10.4
5.2
6.2
8.3
10.4
5.2
6.2
8.3
10.4
5.2
6.2
8.3
10.4
Motile
spirilla/field
@ 30 mins
1-10
0.1-1
1-10
0
0
0.1-1
0
0
0
1-10
1-10
0
0
0.1-1
0.01-0.1
0
0
1-10
1-10
0.1-1
0.01-0.1
Effective
Cl cone.,
ppm
6.2-8.3
5.2-6.2
6.2-8.3
6.2-8.3
^ 10.4
130
-------
Table 44. CHLORINE UPTAKE BY SECONDARY WASTES AND BY SULFITE
Date
(1972)
March 14
March 14
March 15
March 16
April 10
Sample
Effluent (1:10)
Influent (1:10)
Influent (1:10)
Effluent (1:10)
NaHS03 in water
Sulfite
in sample,
ppm
0.25
19.0
14.0
0.22
10.5
Cl
added,
ppm
50.0
50.0
48.0
50.0
92.0
5 Min
Cl resid.,
ppm
41.0
31.0
22.0
43.0
82.0
Chlorine uptake
ppm
9.0
19.0
26.0
7.0
10.0
% of
added
18
38
54
14
11
% of total
due to SOV*
2.4
90
48
2.9
93
-------
with chlorine become less important. Less than 3 percent of the total
chlorine uptake by diluted effluent could be attributed to sulfite.
In actual practice however sulfite in undiluted effluent may have a
greater effect on chlorine requirements. The mean sulfite concentra-
tion of 22 secondary effluent samples was 3.6 ppm with a range of 2.8
ppm to 4.9 ppm (Table I, Appendix). In terms of chlorine demand the
mean would be 3.2 ppm with a range of 2.5 ppm to 4.4 ppm. The mean
chlorine demand value is approximately half of the total chlorine
requirement of secondary effluent. It is important to recognize that
the sulfite values shown may be too high. The iodate titration proce-
dure used is not specific and it does give high values in the presence
of organic matter.
In view of the practical importance of sulfite with respect to chlorine
requirements, additional studies were made to determine the nature and
rate of its oxidation. A mixture containing 50 percent secondary
influent and 50 percent secondary effluent (v/v) was used in the tests.
To evaluate the role of microorganisms half of the mixture was heated
for 2 hours at 80ฐ C to kill a substantial portion of the microbial
population, then cooled to room temperature. To measure oxygen uptake
rates, a portion of this mixture and the unheated control were mechani-
cally aerated and transferred to BOD bottles. D.O. concentrations
were measured at intervals. For the determination of sulfite oxidation
rates, the mixtures were transferred to 2 L graduated cylinders and
aerated mechanically at the start of the test and at intervals of one
hour or less. Periodically, aliquots were titrated with standard
iodate to determine sulfite concent:
to saturation throughout this test.
3
iodate to determine sulfite concentrations. D.O. levels were close
For both samples D.O. utilization was linear with time until D.O.
concentrations became limiting (Figure 35). The unheated control
consumed oxygen at a rate of 1.9 ppm/hr compared to only 0.2 ppm/hr
for the heated sample. Thie represents an 89 percent reduction due to
132
-------
00
Q,
O
o
CO
O
O
14-
12-
10-
8-
6-
0
oo
0.0
& A
A--A
UNHEATED WASTE-D.O
UNHEATED WASTE - S03=
HEATED WASTE - D. 0.
HEATED WASTE - S03=
2
468
REACTION TIME, hours
10
Figure 35. D.O. uptake and sulfite oxidation by mixtures of secondary wastes.
-------
heating. The curves relating sulfite oxidation and time show that the
unheated control oxidized 1.35 ppm of SO., per hour. The rate for the
heated sample was 0.51 ppm/hr. The reduction due to heating was 62.2
percent which indicates that biological activity plays an important
role in the oxidation of sulfite in secondary wastes (Table 23).
The contribution of sulfite oxidation to total oxygen uptake in the
wastes was calculated according to the following considerations. In
the reaction:
1 ppm D.O. reacts with 5 ppm SCL . The amount of D.O. required for
an oxidation can be obtained by dividing the amount of SCL oxidized
by 5. The percent of total D.O. uptake due to sulfite oxidation was
calculated with the following equation;
S03= Oxid, 7ป _ SO ~ ppm/hr x 0.2 ^ IQQ
of Total Oxidation D.O. , ppm/hr
Sulfite oxidation was determined by chemical analysis for sulfite, at
intervals. Total D.O. utilization was measured with an oxygen probe
under conditions where oxygen was not rate limiting.
It was found that sulfite oxidation could account for only 14 percent
of the total D.O. uptake in the control and for 51 percent in the
heated sample. In the latter case much of this oxidation was probably
chemical. As indicated earlier, however, on a rate basis sulfite was
utilized more rapidly in the unheated sample.
The finding that SO-" oxidation takes place slowly in secondary wastes
and that it is due mainly to microbial activity has practical implications.
For example, the mean sulfite concentration for influent samples taken
134
-------
over a five month period was 142 ppm (Table II, Appendix). At an
oxidation rate of 1.35 ppm/hr, as was measured for the unheated
control, it would take 4.3 days for complete oxidation of the sulfite.
This is close to the retention time of the aerated stabilization
basins when operated in parallel. Any condition which would decrease
the rate of sulfite oxidation or increase the amount of sulfite added
to the basins could result in higher concentrations of sulfite in
secondary effluent and, consequently, higher chlorine requirements
for coliform control. Using the results obtained with the heated
waste, as an extreme example, it can be calculated that 11.6 days
would be required for complete sulfite oxidation or that after the
normal retention time of 4.8 days there would still be approximately
88 ppm sulfite remaining with a rapid chlorine demand of 71 ppm.
Sulfite is largely responsible for the high chlorine requirement of
secondary influent. However it is not the only chlorine demanding
compound present. For example, the influent sample taken on March 15
had a larger chlorine requirement than the sample taken on March 14
(Table 44) even though the former contained less sulfite.
Carbohydrates
If the BOD load to secondary treatment ponds is increased, it is
probable that the concentration of sugars in secondary effluent also
will increase. The relevance of this to mill chlorination was
evaluated using glucose as a representative reducing sugar. At a
chlorination rate of approximately 10 ppm, chlorine uptake by a 1000
ppm glucose solution was only about 5 percent of that found for
secondary effluent. At higher chlorination rates the value increased
to 11 percent (Table 45). Increased sugar concentration in effluent
due to overloading would, therefore, not significantly increase
chlorine demand.
135
-------
Table 45. COMPARISON OF CHLORINE UPTAKE BY
SECONDARY EFFLUENT AND GLUCOSE
Sample
Sec. effluent
1000 ppm Glucose
Sec. effluent
1000 ppm Glucose
Cl
added,
ppm
10
8.3
50
42
5 Min
Cl resid.
ppm
0.85
7.8
15
38
Cl
uptake,
ppm
9.2
0.5
35
4
Cl uptake
by glu., % of
uptake by eff.
a
5.4
a
11
aNo glucose added.
Particulates
During secondary treatment there is a seven fold increase of total
bacteria in the waste (Table 10). In effluent samples the mean
concentration of total bacteria was 2.8 billion per 100 ml. The large
standard deviation (SD) of - 2.6 billion per 100 ml suggested that
wide variations in the concentrations of bacteria and other particles
could affect the chlorine requirements of secondary effluent. This
possibility was evaluated by determining the relative reactivity,
with chlorine, of the soluble and particulate components of effluent.
To separate the .components, a secondary effluent sample was centrifuged
for 5 minutes at a force of 9750 xg. The supernatant was clarified
further by filtration through a 0.45 um porosity membrane filter.
Various amounts of chlorine were added to sub-samples of the particle
free effluent and to sub-samples of effluent which had not been
treated to remove particles. Total residual chlorine was determined
after contact times of 5 minutes. The differences in chlorine uptake
by the two sets of samples were attributed to particles. When the
concentration of added chlorine was in the range of 4 to 10 ppm, the
average chlorine uptake by particles was approximately 0.4 ppm and it
did not increase with increasing rates of chlorine addition (Table 46).
136
-------
Table 46. CHLORINE UPTAKE BY PARTICIPATE AND SOLUBLE
COMPONENTS OF SECONDARY EFFLUENT
Cl
added,
ppm
0
2.0
4.0
6.0
8.0
10
5 Min Cl res, ppm
Effluent
0
0
1.6
2.2
3.0
4.0
Effluent
- particles
0
0
1.9
2.7
3.5
4.2
Cl uptake, ppm
Effluent
0
0
2.4
3.8
5.0
6.0
Effluent
- particles
0
0
2.1
3.3
4.5
5.8
Cl uptake due
to particles
ppm
0
0
0.3
0.5
0.5
0.2
Percent
0
0
12
13
10
3
Chlorine uptake due to particles was only 10 percent of the total
chlorine uptake by secondary effluent. These results show that wide
variations in concentrations of bacteria and other particles will
have little effect on the amounts of chlorine required to obtain
residuals in secondary effluents.
Lignosulfonates
The maximum chlorine demand of reducing sugars plus particles in
secondary effluent is approximately 1 ppm. Sulfite may increase the
demand to approximately 4 ppm although this estimate may be too high
(see Sulfite). This is considerably less than the chlorine uptake
by all of the constituents of secondary effluent. In previous
experiments, it was found that chlorine uptake by secondary effluent,
within 5 minutes, exceeded 25 ppm and was proportional to added
chlorine up to at least 40 ppm (Figure 27). This is 10 times the
requirement associated with the materials considered thus far. Other
reactants are not present in great excess because when equal amounts
of chlorine were added to mixtures of secondary effluent and water,
the amounts of chlorine reacted decreased in proportion to the
decrease in effluent concentration (Table 47, Figure 36).
137
-------
u>
00
e
O
Q
O.
ID
g
31
O
10 ppm CHLORINE
ADDED
0
EFFLUENT CONCENTRATION.
Figure 36. Effect of effluent concentration on chlorine uptake.
-------
Table 47. RELATIONSHIP BETWEEN EFFLUENT CONCENTRATION
AND CHLORINE UPTAKE
Sample vol . ,
ml
Eff .
0
6.25
12.5
25.0
50.0
100
Water
100
93.75
87.5
75.0
50.0
0
Cl
added ,
ppm
10
10
10
10
10
10
5 Min
Cl resid.,
ppm
9.9
9.05
9.45
8.61
7.30
4.82
Chlorine uptake
ppm
0
0.85
0.45
1.29
2.60
5.08
% of Added
0
8.5
4.5
12.9
26.0
50.8
It is likely that lignosulfonates are responsible for most of the
chlorine uptake by the secondary effluent for the following reasons:
a. Excluding cellulose, they are the major reaction products of the
sulfite process.
b. They are resistant to microbial breakdown
10
c. They contain unsaturated aliphatic and aromatic groups which can
8
react with chlorine.
d. The capability of secondary effluent to react with large amounts
of chlorine has not been associated with any other materials.
The amount of lignosulfonates going into the secondary ponds may vary
in response to changes in the ratio of normal to high yield cooks
and/or variations in the amounts of lignosulfonates utilized for by-
products. The variations observed in chlorine uptake by secondary
influent samples, independent of their sulfite concentrations, (Table
44) may have been due to differences in lignosulfonate concentrations
caused by the variations in processing. This also may explain the
inconsistent results obtained when secondary effluent was chlorinated
using the mill system (Table 34).
139
-------
SECTION XI
FULL SCALE CHLORINATION
DESCRIPTION OF CHLORINATING SYSTEM
A schematic of the mill chlorination system is presented in Figure 37.
The chlorinator, which is not shown, was a Wallace and Tiernan Series
V800 Module with a maximum metered chlorine output of 454 Kg/day
(1000 #/day). Injector water flow supplies the pressure drop necessary
for the operation of the chlorinator and dilutes the chlorine to
approximately 3500 ppm. The chlorine solution is discharged into
turbulent effluent in #2 sump. This mixes in a Parshal flume with
unchlorinated effluent from #1 sump. The combined effluents are then
discharged to Mark Slough which provides a retention time of 4 to 6
hours before reaching the South Santiam River.
Effluent flow was continuously recorded in thousands of gallons per
hour (TGH). Chlorine flow, which \BS manually adjusted, was indicated
by a rotameter calibrated in pounds per day. The initial concentration
of chlorine in effluent was calculated by the following formula:
Initial = 5 x #/Day Cl
Cl Cone, ppm ~ Total Flow, TGH
On the basis of results from the laboratory experiments, provisions
were made for increasing the pH of the chlorinating solutions. A port
was installed in the injector water supply to allow addition of NaOH
or other solutions.
140
-------
TOP VIEW
SEC. EFF. POND 1
#1 SUMP
WEIR
SEC. EFF. POND 2
#2 SUMP
WEIR
A
PARSHALL
X
FROM
CHLORINATOR
INJECTOR
WATER
SUPPLY
9 INJECT.
PORT
TO
Figure 37. Mill secondary effluent discharge and chlorination systems.
-------
EFFECT OF NaOH ADDITION ON CHLORINE ACTIVITY
A series of tests made during May 1972, showed that the existing
chlorination system was not able to supply bactericidal concentrations
M
of chlorine consistently. In 4 out of 5 trials, motility of spirilla
was not stopped by 19-23 ppm of added chlorine (Table 48)ซ
Table 48. EFFECT OF MILL CHLORINATION ON BACTERIAL
MOTILITY AND COLIFORMS. SUMMARY OF DATA
Measurement
Chlorine required
to stop motility, ppm
Chlorine required
for 99.99% coliform
reduction, ppm
Drop in effluent pH
due to chlorination
Date (May 1972)
17
. 21.2
__a
,0.5
18
;-2l.2
. 21.2
- 0.5
19
19.2
__
.-.-0.5
25
20.4
20.4
0.6
26
; 23.5
--
,0.6
a -- Not determined.
This was equivalent to the maximum metered output of the chlorinator
of 454 Kg/Day (1000 #/day). The variations in applied chlorine
concentrations were due to differences in effluent flow rates.
Complete results for these experiments are given in Table V, Appendix.
In other mill trials it was found that the addition of caustic to the
chlorinator"s injector water supply dramatically improved chlorine
performance. For example, without caustic addition, more than 17 ppm
chlorine were required for bactericidal activity and in some cases
required concentrations could not be reached. With the addition of
caustic, bactericidal concentrations of chlorine were obtained with 4.2
to 7.0 ppm of applied chlorine (Table 49). These results confirm the
findings of laboratory experiments on pH effects which were discussed
142
-------
Table 49. USE OF CAUSTIC IN CHLORINATION SYSTEMS.
SUMMARY OF MILL EVALUATIONS
Date
(1972)
May 25
May 26
June 29
July 20
July 21
Mean
Chlorine req.
for bactericidal
activity, ppm
No
NaOH
20.4
> 23.5
__a
;> 9.1
16.4
17.4
With
NaOH
4.5
7.0
4.2
5.6
5.0
5.3
Total residual
chlorine, t
5 Minutes
No
NaOH
2.7
2.6
--
1.7
3.2
2.6
With
NaOH
0.78
1.7
1.4
2.7
1.7
1.7
jpm after:
2 Hours
No
NaOH
0.86
0.86
--
0.69
1.7
1.0
With
NaOH
0
0
0
0
0.52
0.10
Effluent pH
Before
Chlor.
6.9
6.9
--
6.4
6.6
M
After chlor.
No
NaOH
6.3
6.2
--
--
5.8
* *
With
NaOH
7.0
6.8
--
6.6
ป
Change due to
chlorination
No
NaOH
-0.6
-0.7
--
...
-0.8
-0.7
With
NaOH
4-0.1
-0.1
--
--
0
0
a -- Not determined.
-------
in the preceeding section. Caustic addition had other beneficial
effects. By neutralizing HC1 and HOC1 formed by chlorine hydrolysis,
it held effluent pH changes to - 0.1 unit. Without caustic,
chlorination caused changes of 0.6 to 0.8 pH unit. In only 1 out of
5 trials was there any residual chlorine after 2 hours when caustic
was used, whereas, conventional chlorination consistently produced
2 hour residuals.
Results from individual trials showed some interesting effects due to
the pH of chlorinating solutions. When NaOH was used to increase
the pH, excellent correlation was found between chlorine concentrations
required to produce a 5 minute residual, to stop bacterial motility
and to reduce coliforms to satisfactory levels (Table VI, Appendix).
Without caustic addition, 5 minute residuals could be attained which
persisted for 2 hours but there was little or no correlation between
this and bactericidal activity. Results from the trial of July 21
provide a good example of this.
Without caustic addition, chlorine uptake was proportional to that
added over the entire concentration range which provided a 5 minute
residual (Figure 38). The curve is similar to that found with sodium
hypochlorite in laboratory studies and shows that the increase in
reaction rates is due to an increase in the concentration of one of
the reactants; namely, chlorine.
Relationships between chlorine uptake and added chlorine were complex
when caustic was added to the system. At the lower addition rate of
8 ppm NaOH, chlorine uptake increased only slightly with increasing
rates of chlorine addition, up to about 13 ppm of added chlorine.
Further increases in concentrations caused a sharp increase in the rate
of chlorine uptake. After the break point, the slope of the Chlorine
Uptake vs Chlorine Added curve became steeper than the one obtained
for the control of chlorination (Figure 38).
144
-------
Ui
18-
14.
o_
d.
10-
01
o
IE
O
0 o NO CAUSTIC ADDED
A -A 8 ppm(AVE) CAUSTIC ADDED
EG 17 ppm(AVE) CAUSTIC ADDED
2-
1
ฑ
12 4 6 8 10 12 14 16 18 20 22 24
CHLORINE ADDED, ppm
Figure 38. Effect of caustic addition on chlorine uptake
by secondary effluent. Mill chlorination.
-------
This coincided with a decrease in the pH of chlorinated effluent
(Table VI, Appendix) and indicates a drop in the pH of the chlorinating
solution and a shift in equilibria of chlorine species toward the more
reactive forms, i.e. hypochlorous acid and molecular chlorine. The
greater rate of chlorine uptake in the experimental system, after the
breakpoint had been reached, may have been due to higher reaction
temperatures near the contact point. The heat could be generated in
part by dilution of the concentrated caustic solutions in the injector
water and by neutralization reactions between diluted caustic and
chlorine.
The importance of maintaining a high pH chlorinating solution is also
shown in the relationships between applied chlorine and the 5 minute
chlorine residuals. Using conventional chlorination, residuals were
obtained with 10.6 ppm of applied chlorine and their concentration
gradually increased in a linear manner with increased rates of
application (Figure 39). With the modified procedure using caustic,
residuals were obtained at lower chlorine addition rates and they
increased much faster as more chlorine was added, up to a concentration
of 13 ppm, With further increases, the chlorine concentration of
residuals decreased. This again demonstrated that neutralization
reactions were not complete and that there was a change in the nature
of the chlorinating solution, i.e., the conversion of slow reacting
sodium hypochlorite to the more reactive forms because of pH changes.
CAUSTIC REQUIREMENTS FOR IMPROVED CHLORINATION
According to the following reactions, 1 mole of molecular chlorine
requires 2 moles of NaOH for complete neutralization:
C12 + H2ฐ >HC1 + HOC1
2 NaOH + HC1 + HOC1 >NaCl + NaOCl + 2 H0
2 NaOH + C1 >NaCl + NaOCl
146
-------
E
CL
CO
uu
01
O
O
O>
-I
6_
4J
2-
1 2
0 NO CAUSTIC ADDED
-A 5-8 ppm CAUSTIC
6 8 10 12 14 16
CHLORINE ADDED, ppm
18 20 22 24
Figure 39. Effect of caustic addition on chlorine residuals obtained from mil
chlorination of secondary effluent.
-------
On a weight basis the requirement is 1.128 parts of NaOH (2.256 parts
of commercial 507, caustic) per part of chlorine. Calculations based
on this were made using data obtained on May 25 and 26 (Table VI,
Appendix). The results (Table 50) show that 89 to 96 percent of the
chlorine added to effluent reacted within the first 5 minutes, if the
chlorinating solution was not neutralized. With the addition of NaOH,
chlorine uptake was reduced to 49 to 85 percent defending on the
amounts of chlorine and caustic used. The relationships between the
degree of neutralization (theoretical) and chlorine uptake appeared
to be incongruous. For example, at chlorine application rates up to
272 Kg/day (600 #/day) the low and medium NaOH additions were more
beneficial than the high rate of NaOH application. With further
increases in chlorine the highest rate of NaOH addition was more
effective. To generalize, the lower rates of caustic addition were
more effective unless the amount of NaOH added became a limiting
factor. Neutralization rates of 40 to 50 percent of the theoretical
amounts required for complete neutralization improved chlorination
performance. This indicates that neutralization of the HC1 formed
from chlorine hydrolysis may be adequate and that neutralization of
the other acidic hydrolysis product, hypochlorous acid, was not necessary.
The relatively poor performance of high concentrations of caustic was
probably due to methods of application. The most satisfactory procedure
was used for the lowest application rate. A 25 percent NaOH solution (w/w)
was pumped from a 5 gallon bucket into the injector water line
by a continuous delivery Jabsco pump. Usage was determined by periodic
weighing of the bucket. To obtain higher application rates it was
necessary to use a double action piston pump and 50 percent NaOH.
This tended to give intermittent rather than continuous delivery and
possibly slowed the rate of caustic dilution with injector water.
Either condition would produce a chlorinating solution of fluctuating
pH and one which would vary in effectiveness. These problems would be
expected to increase with higher rates of caustic addition.
148
-------
Table 50. EFFECT OF NaOH ADDITION RATES ON CHLORINE RESIDUALS
Chlorine
added
Ku/day C'/day)
45 ( 100)
68 ( 150)
91 ( 200)
113 ( 250)
13b ( 300)
182 ( 400)
271 ( 500)
272 ( 600)
318 ( 700)
"1 (. 200)
136 ( 300)
182 ( 400)
::? (. 500)
272 (. t,00)
318 ( 700)
3t>3 ( 300)
408 ^ 900)
454 (10001
ppm
2.2, 2.1
3.2, 3.2
4.2, 4.5
5.2, 5,7
6.2, 6.8
8.2, 9.1
10.2, 11.1
12.5, 13.0
14.5, 15.2
3.6-4.8
5.5-7.0
7.3-9.5
9.3-12.1
10.8-14.6
12.8-16.7
14.3-19.0
lb.1-21.3
17.7-23.5
NaOtl added, ppm
Cont
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Low
rate
6.0
6.1
6.5
6.5
6.5
6.6
6.4
6.2
6.3
5.2
5.0
4.3
5.4
6.1
6.0
7.7
3.4
3.4
Med
rate
a
--
--
--
--
..
--
--
8.5
8.4
12
4.8
7.7
6.1
7.5
10
5.8
High
rate
--
--
--
--
--
--
--
18
13
18
16
18
18
18
18
18
Cl neut, 1, of theo
NaOH add. rate
Cont
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Low
253
169
128
101
85
64
51
42
37
96
63
40
40
37
32
36
14
13
Med
--
--
--
--
--
--
160
106
116
38
53
37
40
48
25
High
..
--
--
--
--
--
--
--
--
443
210
219
153
148
125
112
99
90
5 Min Cl resid. , ppm
NaOH add. rate
Cont
0
0
0
0
0.69
0.69
1.1
1.4
1.4
0
0
0
0.43
0.69
0.95
1.7
2.0
2.6
Low
0
0
0.78
1,4
1.6
3.1
5.9
6.5
5.6
0
1.7
2.5
5.3
5.8
4.5
3.0
3.1
--
Med
..
--
--
--
--
--
--
--
--
0
1.4
--
5.1
6.6
6.2
4.3
4.1
3.2
High
..
--
--
--
--
.-
--
--
--
0
0
1.7
2.6
3.1
4.3
6.0
4.7
6.1
Cl uptake, '/, of added
NaOH add. rat
Cont
100
100
100
100
89
92
89
89
90
100
100
100
96
95
94
91
90
89
Low
100
100
83
75
76
66
47
50
63
100
76
74
56
60
73
84
85
Med
..
--
--
--
--
--
--
--
--
100
80
--
54
49
58
74
78
84
High
..
--
--
--
--
--
--
--
--
100
100
77
72
71
66
58
71
66
* -- Not
-------
Time also may have been a factor limiting the- effectiveness of high
levels of NaOH. The following reactions have to occur within a few
feet of pipe containing rapidly flowing liquids:
a. Uniform mixing of caustic and injector water.
b. Complete solution and ionization of NaOH before contact with
chlorine.
c. Hydrolysis of Cl to HC1 and HOC1.
d. Neutralization of HC1.
The pHs of chlorinated effluent (Table VL, Appendix) reflected the
increases in rates of caustic addition. This and measured rates of
addition gave evidence that one or more of the above steps were limiting
the activity of added NaOH.
Results from several mill trials (Table VI, Appendix) showed that
chlorine at an application rate of 113 Kg/day (250 #/day) was effective
against coliforms in secondary effluent, providing the HC1 from
chlorine hydrolysis was neutralized. This would require 65 Kg/day
(143 #/day) of 100 percent NaOH or 130 Kg/day (286 #/day) of commercial
50 percent caustic.
EFFECT OF AMMONIA ADDITION ON CHLORINE ACTIVITY
The low cost of ammonia compared to caustic (Table 51) prompted an
evaluation of its neutralizing properties. Ammonia gas at a cylinder
pressure of 4.9-5.6 Kg/cm2 (70-80 psi) was injected into the chlorinator's
water system which was maintained at 1.8-2.1 Kg/cm (25-30 psi). The
ammonia cylinder was kept in a bucket which received a constant flow
of effluent to prevent cooling of the gas and associated drop in
pressure. Chlorine concentrations were calculated from the application
150
-------
rate and effluent flow, measured at the time of sampling. Ammonia
usage was determined from periodic weighings of the cylinder. The
recording effluent flow meter and point of ammonia application are
shown in Figure 40.
Table 51. ESTIMATED NEUTRALIZATION COSTS
WITH NaOH AND NH&
Evaluation
Reaction
Ratio, Base:Cl
(w/w)
Daily req., Kg
Cost
$/Kg
$/Day
NaOH
Neutralizing agent
NaOH + C12
~ NaCl + HOC1
40:70
(50%) 80:70
65 (143)
(50%) 630 (286)
0.0599 (0.0272)
3.89
4- Cl2 + H~0
NH^Cl + HOC1
17:70
28 (61)
0.0628 (0.0285)
1.74
aBased on amounts required to neutralize HC1 from the
hydrolysis of 113 Kg/day (250 #/day) of C12-
The amount of chlorine required to produce 5 minute residuals was
lowered from approximately 12 ppm to approximately 6 ppm (Table 52)
by the use of ammonia. However, higher concentrations were required
to stop bacterial motility, 16.5-18.2 ppm with ammonia and from 19.1
to more than 21 ppm without it. Complete results from four experiments
are given in Table VII, Appendix. To attain bactericidal solutions,
272 - 363 Kg/day of chlorine and 65 - 93 Kg/day of ammonia were required.
The cost of chlorination would be from $39 to $50 per day. This
compares with $18 per day for bactericidal solutions attained with
113 Kg/day of chlorine and 65 Kg/day of NaOH.
151
-------
Figure 40. Apparatus for ammonia addition to
chlorinator water supply.
152
-------
Table 52. EVALUATION OF AMMONIA AS A NEUTRALIZING AGENT--
SUMMARY OF MILL EXPERIMENTS
Date
(1972)
May 16
May 17
May 18
May 19
Chlorine requirement, jrpm
For 5 min resid
With
NH,
6.8
--
--
4.4
Without
NH0
12.5
--
__
9.6-11.0
To stop motility
With
NH0
__b
18.2
16.3
16.5
Without
NH,
19.1
> 21.2
> 19.2
pH change
due to
NH0
+0.2
0
+0.2
+0.1
NH3 added3
Kg/day (#/day)
10 (104)
87 (192)
65 (144)
93 (204)
% of
req
65
99
74
120
provide a 5 minute residual and/or stop motility.
b __ Not determined.
-------
Reactions between chlorine and ammonia to form chloramines may be
partially responsible for the ineffectiveness of ammonia as a neutralizing
agent. Also, as a weak base it is only 0.4 percent ionized in 0.1 M
solution. Only this small fraction of potentially available hydroxyl
ions is available at a given instant. As reactions occur, the equilibrium
is maintained and in time the full neutralizing capacity of applied
ammonia may be realized. This may explain why ammonia raised the pH
of effluent (Table 52) but was not effective in neutralizing acid from
chlorine hydrolysis. There is not much time between the mixing of
ammonia and chlorine and contact with the effluent. There is a relatively
long period between the chlorination of effluent and the measurement of
its pH.
In contrast, sodium hydroxide is 73 percent ionized in 0.1 M solutions.
Hydroxyl ions are in high concentration and available for neutralization
reactions.
MODIFIED MILL CHLORINATION SYSTEM FOR USING CAUSTIC
The chemical addition port was moved from the horizontal section of the
chlorinator water supply (Figure 40) to the vertical section to obtain
better mixing. Because of the great distance, 244 M (800 ft), between
an available caustic storage tank and the chlorinator, a double pump
system was required. Caustic was pumped through 244 M (800 ft) of
1.27 cm (1/2") iron pipe to a piston pump for injection into the
chlorinator's water supply. The transfer of caustic from storage was
made with a Moyno pump fitted with a pressure regulator and recircula-
tion loop to accommodate its high output.
Dimensions of the storage tank were 2.44 M in diameter and 4.24 M high
(8 ft x 13.9 ft). Its capacity was 19.8 M^ (5240 gal.)- At a usage
rate of 216 L/day (56.94 gal./day) of 23 percent NaOH (w/w), it provided
154
-------
for 91 days of continuous operation. Caustic was diluted to a 23
percent NaOH concentration to prevent it from congealing in cold
weather and to improve its mixability.
The Moyno pump was fitted with a two way valve so that caustic could
be pumped from the main storage tank, or from a 5 gallon bucket for
measuring application rates.
METHODS FOR MONITORING CHLORINATION
As shown in Section X there are several indirect tests for estimating
the effect of chlorine on coliforms, i.e., inhibition of oyxgen uptake
(Oxygen Uptake Test), stopping of motile spirilla (Motility Test),
and the presence of a total residual chlorine after 5 minutes contact
time (5 Minute Residual Test). When effluent is chlorinated with
sodium hypochlorite, there is good correlation between these tests
and results obtained by standard methods for enumerating coliforms
(Tables 36 and 37). Some of the benefits and disadvantages of the
methods are discussed on the basis of practical experience with them.
Oxygen Uptake Test
There is a marked difference in oxygen uptake rates between unchlori-
nated effluent and effluent which has been adequately treated with
chlorine (Figure 31). Definitive results can be obtained within 1 to
2 hours. As a laboratory test it demands considerable working time
and attention. However, these drawbacks can be overcome by modifications
for field use. For example, chlorinated effluent can be continuously
metered into a long channel with plug flow characteristics. The
channel can be calibrated in units of time for known effluent flow
rates. By measuring D.O. concentrations at two points the rate of
oxygen uptake can be calculated as ppm/hr. A control channel may not
be necessary if unchlorinated effluent is consistent in its rate of
155
-------
oxygen uptake. The test made in this manner would provide information
on the effectiveness of chlorination averaged over the preceeding hour
or two. It would not indicate how effective chlorination is at a
given instant. For this information initial and final D.O. concentra-
tions could be determined on grab samples collected in BOD bottles.
Motility Test
This method provides results within 30 minutes and is easy to carry
out in a laboratory. It does require a phase microscope to make
bacteria visible without staining and is not appropriate for field use
where there is a risk of rough handling and/or contamination of the
optics. On rare occasions the concentrations of motile spirilla,
the indicator organisms, decreased to very low concentrations in
unchlorinated effluent. This made it more difficult and time consuming
to evaluate the effects of chlorine. It is conceivable that even
greater changes could occur making the method useless. Laboratory
studies (Table 53) indicated that it is possible to carry out the test
with pure cultures of motile bacteria grown in a nutrient medium. Of
three species tested Pseudomonas aeruginosa was the most satisfactory.
It grew rapidly in nutrient broth to high concentrations of motile
cells. A 1:100 dilution of a 1 day old culture provided 1-10 highly
motile cells, as observed under 450x magnification. The motility of
P. aeruginosa added to secondary effluent was stopped by 10 ppm
chlorine within 5 but not within 2 minutes. This is similar to the
chlorine sensitivity of spirilla, the naturally occurring indicator
organisms.
5 Minute Residual Test
Results from numerous trials showed that there was excellent correlation
between concentrations of chlorine required to produce 5 minute residuals
and those necessary to kill coliforms, providing the chlorine was
added as sodium hypochlorite. When molecular (gaseous) chlorine was
156
-------
Table 53. MOTILITY AND GROWTH CHARACTERISTICS OF
POTENTIAL INDICATOR BACTERIA
Bacterial species
Bacillus cereus
Proteus mirablis
Pseudomonas aeruginosa
Growth medium
^
Nutrient broth
Nutrient brotha
ปa
Nutrient broth
Effluent
Eff 4- 0.17. glucose
Eff + 0.17. glucose
and 0.17. yeast ext
Nutrient broth
f 0.5% glucose
Amount of
growth
Scanty
Fair
Abundant
Moderate
Abundant
Abundant
Abundant
Motile cells
per fieldI: 100
diln, 450X
None
None
1-10
0.01-0.1
None
1-10
1-10
aNutrient Broth, G/L of water: Beef extract 5.0; Peptone 10.0; NaCl 5.0. pH 6.8.
-------
used, residuals could be obtained in absence of bactericidal activity.
An example of this is shown for July 20, Table VI, Appendix. During
mill chlorinations 9.1 ppm chlorine added as 01 produced a residual
of 1.7 ppm but had no effect on coliform concentrations or bacterial
motility. In contrast, when caustic was added to the system, 3.9 ppm
Cl produced a residual of 1.5 ppm and reduced the coliform population
by 99.996 percent.
Interference by Nitrite and Iron
During evaluation of the 5 Minute Residual Test, it was found that
unchlorinated secondary effluents from the aerated lagoons consistently
gave negative results. However, unchlorinated effluent from the small
EPA unit*contained an apparent chlorine concentration of more than
40 ppm. It was also noted that after titration of liberated iodine
the color would gradually return and additional titrations could be
made (Table 54).
A positive test for total residual chlorine depends on the oxidation
of iodide to iodine by active chlorine according to the following
reaction:
21" + C12 -^I2 + 2C1" (Blue)
Starch
The test is non-specific. Any compound capable of oxidizing iodide
will give a positive result. Ferric iron and nitrite are two such
o
interfering agents. Laboratory tests showed that ferric chloride
at a concentration of 1.7 ppm, as Fe, increased the apparent chlorine
concentration in C.Z.+ effluent (Table 55). However, after the first
titrations there was no return of the blue starch-iodine color. Ferric
iron was not the cause of the false positive tests found for EPA
effluent. Nitrite at a concentration of 0.13 ppm increased the apparent
*See Glossary.
+C.Z. Crown Zellerbach.
158
-------
Table 54. APPARENT CHLORINE RESIDUALS IN UNCHLORINATED
SECONDARY EFFLUENTS
Source of effluent
Large aerated
lagoons
EPA pilot
unit
1st Titration
React
time
30 sec
5 min
1 hr
3 hrs
30 sec
5 min
1 hr
App Cl
ppm
0
0
0
0
34
41
58
2nd Titration
React
time
__ a
1 hr
1 hr
1 hr
App Cl
ppm
--
25
24
24
3rd Titration
React
time
--
3 hrs
3 hrs
3 hrs
App Cl
ppm
--
36
36
Ul
a -- Not done.
-------
Table 55. EFFECT OF FERRIC IRON AND NITRITE ON THE TEST
FOR TOTAL RESIDUAL CHLORINE
Sample
C.Z. effluent
Sept. 14, 1972
River water
C.Z. effluent
Sept. 14, 1972
EPA effluent
Sept. 14, 1972
C.Z. effluent
Sept. 13, 1972
EPA effluent
Sept. 13, 1972
Additive (as Fe or N0?~^
Compound
FeCl3-
6 H.O
2
NaN02
NaNO.
2
NaN00
ฃ.
NaNO
2
NaNO,
L.
Initial
cone , ppm
0
0.4
0.8
1.2
1.7
2.1
4.1
8.3
12.4
16.5
0.0007
0.007
0.066
0.66
6.60
0.066
0.13
0.26
0.39
0.53
0.66
1.31
2.63
3.94
5.26
0
1.31
2.63
3.94
5.26
0
0.20
1.00
2.03
20.20
0
0.20
1.00
2.03
20.20
App Cl, ppm
1st
Titr
1.3
1.3
1.3
1.3
1.7
2.6
3.9
6.0
8.6
10.8
0
0
+a
5.2
59.4
1.3
2.2
2.2
2.6
3.4
3.9
7.7
16.4
20.7
24.1
36.2
38.7
42.2
42.2
45.6
1.3
4.3
16.4
21.5
43-86
37.0
36.2
41.3
43.0
103-11
2nd
Titr
0
0
0
0
0
0
0
0
0
0
0
0
b
--
6.0
0
0
0
0.40
0.86
1.30
2.60
4.30
5.20
6.00
6.0
5.6
3.9
6.0
4.7
0
--
_.
--
--
--
--
--
* *
Increase,
moles
Cl: additive
0
0
0
0
0.40
0.95
1.00
0.90
0.93
0.90
0
0
--
10.0
12.0
0
8.50
4.20
4.20
5.30
5.10
6.40
7.50
6.40
5.60
0
2.6
3.0
2.0
2.3
0
5.9
5.9
3.9
1.2-1.7
0
0
1.7
1.2
1.3-1.5
a -t- = trace.
b -- Not done.
160
-------
chlorine level in C& effluent and 0.39 ppm produced the color reversion
referred to earlier. The molar ratio of apparent chlorine to nitrite
was approximately 5:1 indicating the catalytic behavior of nitrite.
Approximately 5 to 10 ppm NO were required to produce the concentra-
tions of apparent chlorine found in effluents from the EPA unit."1"
Subsequent analyses of 1 day old samples by the diazotization method
showed that CZ effluent contained less than 1 ppb NO ~ and EPA effluent
contained 8.2 ppm. The results show that N0~ was responsible for the
false positive tests for chlorine.
Formation of Nitrite
An effluent sample collected from the EPA unit on September 25 was
found to contain only 8.5 ppm of apparent chlorine, down considerably
from the 36 to 37 ppm found earlier (Table 55). This prompted a study
to determine some of the factors responsible for nitrite formation
which leads to the false positive tests for chlorine. Results from
initial trials showed that both D.O. concentrations and effluent
characteristics, most likely the nature of the bacterial population,
influence nitrite formation. With continuous aeration, the apparent
chlorine concentration in EPA effluent increased to 36 ppm, a value
close to those previously found. The results in Table 56 are expressed
as estimated nitrite concentrations. They were obtained by dividing
apparent total residual chlorine by 3.85. This equivalence was
determined by adding various amounts of N0ป to CZ effluent then
measuring the increase in total residual chlorine. On this basis,
aeration increased the N02" concentrations in EPA effluent from 2.2 ppm
to 9.4 ppm in one day and to 11 ppm within two days. Under the same
conditions, the maximum concentration reached for CZ effluent was 0.68
ppm after two days, indicating a lack of nitrifying bacteria,, When
aeration was stopped, nitrite concentrations decreased in both effluents,
*CZ = Crown Zellerbach.
"*"See Glossary.
161
-------
Table 56. EFFECT OF D.O. CONCENTRATION ON THE FORMATION AND REMOVAL
OF NITRITE IN SECONDARY EFFLUENT
Incubation
conditions
Still--no
aeration
Continuous
aeration
Continuous
aeration
Effluent
C.Z.a
EPAb
C.Z.
EPA
C.Z.
EPA
24 hrs
then still]
PH
Initial
7.2
7.1
7.2
7.1
7.2
7.1
1 Day
7.2
7.1
8.0
7.7
8.0
7.7
2 Days
7.2
7.15
8.1
7.9
7.85
7.50
D.O., ppm
Initial
4.8
5.7
9.0
9.0
9.0
9.0
1 Day
1.4
1.2
8.9
8.8
8.9
8.8
Estimated N02"
ppm
Initial
0.34
2.20
0.34
2.20
0.34
2.20
1 Day
0
0.18
0.57
9.40
0.57
9.40
2 Days
0
0.18
0.68
11.00
0
4.20
CTi
aC.Z. - Crown Zellerbach.
&EPA ซ Environmental Protection Agency.
-------
Nitrite levels continued to decrease in EPA effluent. On September 27
the concentration was only 0.9 ppm the same as found for effluent from
the large secondary ponds (Table 57). This concentration is equivalent
to an apparent chlorine residual of 3.5 ppm, and was unusual for
effluent from the large ponds.
The variation in NO- concentrations in effluent from the EPA unit
coincided with changes in operating conditions. During periods of
high N02 concentrations, influent was not being added to the unit
because of a pump failure. Later, when influent was added at a rapid
rate to restore the normal operating volume, N0? concentrations in
the waste decreased. The following laboratory tests showed that
nitrifying bacteria were still present in effluent from the EPA unit
and indicated that N09 was not being produced because of an increase
in sugars due to reduced retention time.
An effluent sample collected from the EPA unit on September 27 had an
estimated NO ~ concentration of 0.9 ppm. Aeration of a sub-sample
increased the N0~~ level to 9.4 ppm within one day, showing that active
nitrifiers were still present (Table 57). Another sub-sample was
treated to contain 8.7 ppm NO." and 0.8% (w/v) glucose. When this
material was continuously aerated there was a decrease in NO^ to
2.3 ppm after 1 day and to 0.27 ppm after 7 days. In the same
experiment it was found that effluent from the large C.Z. ponds did
not contain active nitrifiers. Aeration of a sample of this material
for 7 days did not lead to N02~ formation.
There was some evidence that bacteria from the large ponds were more
active than bacteria from the EPA unit with respect to sulfite (S03 )
oxidation. When influent was inoculated with 5 percent effluent from
the large ponds, S03= decreased from 104 ppm to 3 ppm within 1 day as
compared to a decrease to 41 ppm for the same influent inoculated
with 5 percent effluent from the EPA unit.
163
-------
Table 57. FACTORS AFFECTING NITRIFICATION
Sample
description
EPA effluent
collected
9/27/72
C.Z. effluent
collected
9/27/72
Secondary
influent
9/27/72
Additives
Material
None
Na2S03
NaN02
glucose
Secondary inf
None
EPA eff (9/25)
C.Z. eff (9/27)
EPA eff (9/25)
Final
cone
0
17 ppm
8.0 ppm
0.87.
107.
0
1.07.
5.0%
5.07.
PH
Ini
7.3
7.5
6.9
7.3
7.2
7.2
7.3
7.1
4 D
7.3
7.4
5.0
7.6
8.0
7.9
7.7
7.6
7 D
6.2
6.7
4.8
7.4
8.0
7.8
7.6
7.6
Estimated N02",
Ini
0.90
0
8.70
0
0.90
0.90
0
0
1 D
9.4
8.1
2.3
6.9
0.67
0.49
0
0
ppm
4 D
12.8
11.6
0.90
12.1
0.58
0.78
0.40
0.40
7 D
10.1
13,0
0,27
12.8
0.67
0.78
0.49
0.40
Ini
1.8
17.0
1.8
9.2
1.8
1.8
104
104
SO, , ppm
1JD
3.2
2,9
3.0
2.6
3.2
2.9
3.2
41
u ;; j
2.1
2,3
2.5
2,4
2,5
3.0
2,3
2,0
7 D
2,6
2,9
3.9
2.4
2.4
2.9
2.5
2.3
-------
The preceeding shows that wastes being treated in the two types of
ponds differed biochemically. It was found that they also differed
in other ways. Turbidity in effluent from the large ponds did not
decrease upon standing. In marked contrast, the particles responsible
for turbidity in effluent from the EPA unit settled rapidly.
Microscopic observations showed further differences between the
effluents. Numerous fibers were observed in effluent from the EPA
unit but few in the waste from the large ponds. Figure 9 illustrates
the differences seen in the microbial populations. Effluent from the
large aerated ponds contained a diverse group of bacteria which were
well dispersed. Bacteria in effluent from the EPA unit were concentrated
within partially degraded fibers or in zoogleal masses.
Nitrite also may be formed in soils by the bacterial oxidation of
NH,+ from commercial fertilizers or from animal wastes. Under
4
anaerobic conditions, other types of bacteria can reduce nitrate to
NO ~. Leaching and runoff from soils are two mechanisms by which
N0?~ could enter streams.
Significance of Nitrite
Negative results from tests for total residual chlorine are conclusive.
However, positive results under suspect conditions will require
further checking because of possible nitrite interference. In the
quantitative analysis for total residual chlorine, if the blue color
of the starch-iodine complex returns after an end point has been
reached, this may indicate nitrite interference. In this case total
residual chlorine analyses of samples taken upstream and downstream
from an effluent discharge point will indicate the importance of the
waste as a source of residual chlorine and/or N02 .
165
-------
False positive tests for total residual chlorine have been obtained
frequently for samples of effluent treated with molecular chlorine or
chlorine dioxide but rarely for samples treated with sodium hypochlorite.
This may have been due to oxidation of NH, , which is present in the
effluent, to NO, by the stronger oxidizing agents.
pH Measurements
Successful operation of the modified chlorination system depends on
the conversion of Cl~ to HOC1 and/or NaOCl by NaOH addition. Two
rapid methods were used to monitor neutralization reactions:
a. pH measurements were made on injector water sampled downstream
from the point of NaOH addition. Experience showed that when pHs
were in the range of 11.5 to 12.5 an adequate amount of NaOH was being
used. Fluctuations in pH were usually caused by variations in water
flow due to variable use in the mill. pHs less than 11.5 frequently
were caused by decreases in NaOH addition rates due to mechanical
problems.
b. pH measurements were made on effluent samples before and after
chlorination. With adequate caustic addition they were the same.
This proved useful in establishing the correct rate of caustic
application for a constant rate of chlorination.
FACTORS AFFECTING FULL SCALE CHLORINATION
Concentrations of Lignosulfonates
Results from laboratory studies (Table 47) indicated that variations
in the concentrations of lignosulfonates could influence chlorine
requirements. To evaluate this further, samples of effluent were
centrifuged at 9750 xg for 15 minutes to remove particles. The
166
-------
supernatant was diluted 1:10 and U.V. absorbance of the diluted
samples was measured at 280 nm to estimate lignosulfonate levels.
The mean U.V. absorbance for 12 samples was 2.75 - S.D. 0.19 (Table 58)
Table 58. VARIATIONS IN ULTRAVIOLET ABSORBANCE
AND FLOW RATES OF SECONDARY EFFLUENT
Date
(1972)
June 21
July 5
5
6
7
7
8
8
8
10
11
AUR. 7
Mean
S.D.
Var., %
Time
1700
1140
1145
1630
1240
1350
0800
1540
2100
1540
1445
1217
-
U.V. abs
@ 280 nm
3.20
2.60
2.80
3.00
2.75
2.65
2.70
2.55
2.65
2.70
2.75
2.60
2.75
0.19
6.9
Eff flow
I/sec (TGH)
__a ( --)
147 (140)
-- ( -)
304 (290)
310 (295)
236 (225)
284 (270)
257 (245)
307 (292)
215 (205)
131 (125)
315 (300)
251 (239)
68 ( 641
27 ( 27)
a -- Not determined.
The difference between extremes was 0.40 or approximately 14 percent.
This rather limited evaluation indicates that fluctuations in ligno-
sulfonate concentrations would not be a major factor in chlorination.
However, combined with other effects such as flow rate variations it
could become significant.
167
-------
Series vs Parallel Operation
After three days of series operation, effluent samples from Ponds 1
and 2 were evaluated for chlorine requirements. The requirements for
Pond 2 were similar to those of combined effluent from parallel
operation. Between 8 and 10 ppm stopped bacterial motility and
approximately 2 ppm provided a 5 minute residual (Table 59).
Table 59. CHLORINE REQUIREMENTS OF PONDS 1 AND 2
IN SERIES OPERATION. 9/16/72
Chlorine
added,
ppm
0
2
4
6
8
10
20
40
60
80
100
120
5 Min chlorine
residual, ppm
Pond 1
0
0
0
0
0
0
0
0
0
0
1.7
9.4
Pond 2
0
0.43
0.86
1.90
3.00
4.00
9.00
20.00
42.00
45.00
49.00
__a
Motile spirilla
per field @ 30 min
Pond 1
1-10
1-10
1-10
1-10
1-10
1-10
1-10
1-10
1-10
1-10
1-10
0
Pond 2
1-10
1-10
0.1-1.0
0.1-1.0
0.01-0.1
0
0
0
0
0
0
""
a Not determined.
In contrast, for Pond 1 approximately 100 ppm chlorine were required
to produce a residual and between 100 and 120 ppm to stop motility.
This high requirement was due to the higher SO- concentration in
Pond 1, 71.5 ppm compared to 0.51 ppm for Pond 2. A concentration of
71.5 ppm SO,," is equivalent to 63 ppm chlorine. The amount required
in excess of this for Pond 1 effluent may have been due to more complete
and rapid reactions between chlorine and lignosulfonates at high
chlorine levels. The significance of sulfite in secondary wastes is
also discussed in Section X.
168
-------
Results from mill trials made after one week of series operation showed
that 4.9 ppm chlorine reduced colifonns by 99.998 percent providing
caustic was added to the chlorinator's water supply (Table 60).
Without caustic addition the effective concentration was between 21
and 27 ppm.
During series operation spot checks were made to determine the effect
of standard chlorination (113 Kg/day Cl plus NaOH addition) on bacterial
motility. Results at the start of series operation and after 3 and 12
days (Table VIII, Appendix) showed that motility was stopped by 6.0-7.1
ppm chlorine.
The results show that effluent from series operation can be effectively
treated with the same concentrations of chlorine as required for
effluent from parallel operation. However, there is a situation where
the chlorine requirement would be increased tremendously and perhaps
should not be attempted. This would be during the early periods of
change over from series to parallel operation. Due to the decreased
retention time in the first pond SO ~ concentrations will increase.
This is no problem as long as series operation is continued because
SO ~ is reduced to low levels in the second pond and it is only the
effluent from Pond 2 which receives chlorine. After changing to
parallel, the SO ~ concentration will remain high in Pond 1 for a
considerable period. During this time the unchlorinated effluent from
Pond 1 with its high SO ~ level will immediately neutralize chlorine
residuals as it mixes with the chlorinated effluent from Pond 2
(See Figure 37).
Injector Water Pressure
At Lebanon the pressure in the injector water line fluctuated in response
to water usage in the mill. For example, on November 14, 1972 the
169
-------
Table 60. MILL CHLORINATION OF SECONDARY EFFLUENT FROM SERIES OPERATION
WITH AND WITHOUT CAUSTIC ADDITION
Chlorine added
Kg/day (#/day)
0
91 ( 200)
182 ( 400)
272 ( 600)
363 ( 800)
454 (1000)
( 100)
91 ( 200)
113 ( 250)
182 ( 400)
272 ( 600)
363 ( 800)
454 (1000)
ppm
0
5.4
10.8
16.2
21.0
27.0
2.4
4.9
6.0
9.5
14.3
18.9
23.8
NaOH
added
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Eff
PH
7.3
7.0
6.8
6.5
6.6
6.5
7.3
7.2
7.2
7.1
7.0
7.0
6.9
5 min
Cl res, ppm
0
1.0
1.6
2.2
3.4
4.6
0
1.0
1.6
4.6
4.7
10.4
7.0
Motile sp
per field
1.0-10.0
0.1-1.0
0.1-1.0
0.1-1.0
0.01-0.1
0
0.01-0.1
0.01-0.1
0
0
--
--
Coli forms
100 ml ,
44 x 10^
46 x 105
31 x lOj
18 x 10;?
3 x 105
C.100
54 x 10J
100
100
^100
--
--
Colif
redn, %
__a
0
29.546
59.091
93.182
> 99.998
98.773
99.998
99.998
^ 99.998
--
--
"
vj
o
a -- Not determined.
-------
pressure varied from 1.3 to 2.6 Kg/cm2 (19-37 #/in.2). During the
same period caustic use varied from the equivalent of 181 to 286
Kg/day (400-630 #/day). An adjustable pressure regulator valve was
installed in the water line so that caustic could be pumped into the
system against a constant resistance. Tests made on November 21 and 22,
1972, showed that caustic usage was approximately 136 Kg/day (300 #/day)
when pumped against a total pressure (water plus regulator) of 1.76-1.90
2 2
Kg/cm (25-27 #/in. ). When the total pressure was increased to 2.1
2 2
Kg/cm (30 #/in. ) or more caustic usage decreased to approximately
72 Kg/day (160 #/day) an
-------
The cyclic variation in effluent flow rates is shown on the continuous
recorder in Figure 40. These are related to the batch pulping process
with intermittent discharge and washing. Wider variations often occurred
in response to shifting wind velocity and direction over the ponds.
Extremes ranged from no effluent flow to more than 315 1/min (300 TGH),
the highest calibration on the flow meter.
These conditions clearly indicate the need for a chlorination system
which will respond to changes in effluent flow to maintain a constant
initial chlorine concentration. Similar control would also be
required for the caustic addition system. Without it two undesirable
conditions could develop:
Chlorine Addition Rate Increases in Response to Greater Effluent Flow
Rate -- Without a similar increase in caustic application, neutraliza-
tion of chlorine hydrolysis products would be incomplete. Molecular
chlorine would react rapidly with lignosulfonates and would not provide
enough chlorine residual to kill coliforms.
Chlorine Addition Rate Decreases in Response to Reduced Effluent Flow --
Here NaOH would be present in excess and chlorine could be converted
completely to NaOCl. Initial reactions with lignosulfonates would be
relatively slow, leading to high concentrations of residual chlorine.
Reactions from here on would be related to the pH of chlorinated
effluent. If on the acid side, bactericidal activity would be
excellent and a relatively rapid reaction rate might make this
condition acceptable. If the effluent were on the alkaline side,
and excess NaOH would favor this, bactericidal activity would be low
and chlorine residuals could persist for undesirably long intervals.
This suggests the possibility of toxicity in receiving waters if there
is a shift in pH upon dilution from a moderately alkaline waste to a
172
-------
neutral mixture. The chlorinating procedure described, however, has
a built in safeguard against this. The amount of caustic used is
sufficient to neutralize only half of the acids produced from the
hydrolysis of chlorine.
From the standpoint of effectiveness, added protection against stable
chlorine residuals and efficiency of operation, it would be desirable
to vary both chlorine and caustic addition in response to changes in
effluent flow rates. A system to do this has been designed but had
not been evaluated at the time of writing.
Primary Pond Operation*
The main function of the primary pond is to remove fibers and other
particles from mill wastes before they go to secondary treatment.
When the pond is nearly full of accumulated sediment or when it is
being pumped, unsettled waste enters the secondary treatment ponds
and the concentration of particles increases in secondary wastes.
This apparently has no adverse effect on chlorination. For example,
during the period from September 14 to 22, 1972, the primary pond
was nearly full or out of service. Chlorination of secondary effluent
during this time was effective as shown by the Motility Test
(Table VIII, Appendix). However, during the period of inadequate
primary treatment, there was a change in the stability of total
residual chlorine.
In chlorinated effluent samples total residual chlorine consistently
persisted for longer than 2 hours which was unusual. Further tests
showed that unchlorinated effluents also gave positive tests and that
concentrations of 2 hour residuals were similar for chlorinated and
unchlorinated samples. The reason for the false positives was not
*Also see Section IV, Apparatus and Methods.
+See Section X, Activity of Chlorine in Secondary Wastes.
173
-------
determined. However, the results do suggest an interesting possibility.
In the subsection, METHODS FOR MONITORING CHLORINATION, nitrite
formation in the small EPA pilot unit was described. It was found
that nitrite in the effluent catalyzed the oxidation of l" to I- and
in so doing gave a false positive test for total residual chlorine.
One of the ways in which the operation of the EPA unit differed from
that of the large ponds was that influent for the small unit received
no primary (settling) treatment. During the period in question here,
influent to the large secondary ponds also had inadequate or no
primary treatment. For a period, influent to both C.Z. and EPA units
were the same. This suggests that the presence of fibers and/or
other suspended particles leads to the development of a microbial
population capable of nitrification during secondary waste treatment.
For proof of this, however, effects of high D.O. levels, low BOD and
retention time on nitrification would have to be resolved. It is
apparent that the types of bacteria developing on fibers in the EPA
unit differ considerably from the population normally found in the
large treatment ponds (Figure 9).
MONITORING OF FULL SCALE CHLORINATION
Procedure
The conditions established for effective chlorination included a
chlorine application rate of 113 Kg/day (250 #/day) and a caustic
addition rate of 65 Kg/day (143 #/day), based on 100 percent NaOH.
The system was checked frequently to determine how well these condi-
tions were maintained. Chlorine and caustic additions were then
adjusted to the desired rates, if necessary, and bactericidal activity
was estimated with the Motility Test.*
fSee Section X.
174
-------
Chlorine Application Rate
The chlorine delivery rate required few adjustments and was seldom
off more than 1 to 2 Kg/day or - 1-2 percent of the desired rate.
Caustic Delivery Rate
The mean application rate was 81 Kg/day (178 #/day) which was
approximately 24 percent more than desired (Table VIII, Appendix).
Variance for 70 measurements was 37 percent. This was due mainly to
experiments with caustic flow rates and to pump problems. For example,
on September 18 a failure of the Moyno pump allowed water from the
chlorinator's injector line to partially fill the caustic tank. A
check valve was installed to prevent this from occurring again and
the pumping rate was increased to compensate for the dilution of
caustic 0
Data in Table VIII , Appendix, show caustic use only at the time of
monitoring for bactericidal activity. Measurements taken at other times
showed that pumping rates were affected by fluctuations in injector water
pressure. Both impeller type and piston pumps were sensitive to this.
As mentioned previously, an adjustable pressure regulating valve was
installed later so that the pump would be working against a constant
resistance. Time did not permit a complete evaluation of this modification.
Bactericidal Activity
With only one exception chlorination completely stopped motility of
spirilla and on July 20 (Table VIII, Appendix) their concentrations
were lowered from 1-10 per field to 0.01-0.10 per field. As shown in
Section X this is a good indicator of adequate coliform kill.
175
-------
Factors Contributing to 2 Hour Chlorine Residuals
An optimum chlorination procedure would be one which provided sufficient
chlorine to kill coliforms and produce a positive test for chlorine
residual at 5 minutes but not after 2 hours. The first critereon was
met. However, 41 percent of the 70 samples tested gave a positive
test for chlorine after 2 hours. As mentioned in the previous section,
even unchlorinated samples gave positive chlorine tests during the
period of inadequate primary treatment. When the results from this
questionable period were removed, new calculations showed that 16 out
of 57 samples, 28 percent, gave positive tests for 2 hour Cl residual
(Table 61). The following factors could lead to stable residuals:
a. High initial chlorine concentrations due to reduced effluent flow
with a constant rate of chlorination.
b. High caustic addition rates.
c. Low injector water pressure which would lead to increased caustic
addition.
d. High effluent pH.
There was little difference in the mean values of these characteristics
for samples which had 2 hour chlorine residuals and those which did not.
When values for individual samples which had 2 hour residuals are
compared with the means of samples which did not, possible causes for
the stable residuals become apparent (Table 62), in some instances. In
3 of the 16 samples with 2 hour residuals initial chlorine concentrations
were from 22 to 72 percent greater than the mean of samples without 2
hour residuals. In 3 other samples higher than normal caustic addition
rates or low injector water pressure was related to stable residuals.
Possible reasons for stable residuals in the other 10 samples were not
apparent.
176
-------
Table 61. SUMMARY OF PULL SCALE CHLORINATION MONITORING DATA
Sample
description
All samples
Mean
S.D.
Var., 7.
# of samples
All samples with 2 hr
Cl residual
Mean
S.D.
Var., 7.
# of samples
All samples with no
2 hr Cl residual
Mean
S.D.
Var., 1,
# of samples
Chlorine added
Kg/day (#/day)
113 (250)
0
0
70
113 (250)
0
0
29
113 (250)
0
0
34
ppm
5.9
1.0
17
70
6.1
1.3
21
29
5.8
0.6
10
34
Cl resid, _ppm
5 Min
2.4
0.8
33
63
2.7
1.0
37
28
2.1
0.5
24
34
2 Hr
0.5
0.7
140
68
1.1
0.7
64
29
0
0
0
34
NaOH added
K*/day <*/dซy)
81 (178)
30 ( 66)
37
66
74 (163)
21 ( 46)
28
27
80 (177)
23 ( 51)
29
32
Eff flow
L/sec (TGH)
228 (217)
33 ( 31)
14
70
223 (212)
36 ( 34)
16
29
228 (217)
27 ( 26)
12
34
Inj H^O Press.
Kg/cro^Of/in.'O
3.8 (54)
1.1 (15)
28
70
3.7 (53)
1.0 (14)
26
29
3.7 (52)
1.1 (16)
31
34
Eff
pH
7.0
0.2
__
50
7.0
0.2
--
26
7.0
0.2
29
a Mot calculated.
-------
Table 61 (continued). SUMMARY OF FULL SCALE CHLORINATION MONITORING DATA
Sample
description
All samples except
9/14-10/7
Mean
S.D.
Var., 7.
# of samples
Samples with 2 hr Cl
resid except 9/14-10/7
Mean
S.D.
Var., 7.
it of samples
Samples with no 2 hr
Cl resid except 9/14-10/7
Mean
S.D.
Var., 7.
# of samples
Chlorine added
Ka/dav (0/day)
113 (250)
0
0
57
113 (250)
0
0
16
113 (250)
0
0
34
ppm
5.9
0.9
15
57
6.3
1.2
19
16
5.8
0.6
10
34
Cl resid. ppm
5 Min
2.3
0.6
26
50
2.4
0.8
33
15
2.1
0.5
24
34
2 Hr
0.2
0.4
200
55
0.7
0.4
57
16
0
0
0
34
NaOH added
to/day (f/dซy)
84 (186)
22 ( 48)
26
54
80 (176)
10 ( 22)
13
15
80 (177)
23 ( 51)
29
32
Eff flow
L/sec (TGH)
227 (216)
30 ( 29)
13
57
219 (208)
33 ( 31)
15
16
228 (217)
27 ( 16)
12
34
Inj H?0 Press.
Kg/cmi(#/in.iO
3.9 (56)
1.1 (15)
27
57
4.2 (60)
0.97 (14)
23
16
3.7 (52)
1.1 (16)
31
34
Eff
pH
7.0
0.3
47
70
0.3
13
7.0
0.2
--
29
Not calculated.
00
-------
Table 61 (continued). SUMMARY OF FULL SCALE CHLORINATION MONITORING DATA
Sample
description
Samples of 9/14-10/7
(All had 2 hr Cl resid)
Mean
S.D.
Var., %
# of samples
Unchlor eff (All samples)
9/14-10/7
Mean
S.D.
Var., 7.
# of samples
Unchlor eff 9/14-10/7
with 2 hr Cl resid
Mean
S.D.
Var., %
# of samples
Chlorine added
Kg/day (#/day)
113 (250)
0
0
13
0 (250)
0
0
9
0 (250)
0
0
5
ppm
5.8
1.4
24
13
0
0
0
9
0
0
0
5
Cl resid, ppm
5 Min
2.8
1.2
43
13
0.9
0.9
100
9
1.7
0.3
18
5
2 Hr
1.6
0.7
44
13
0.8
0.8
100
9
1.4
0.5
36
5
NaOH added
Kg/day (#/day)
65 (144)
27 ( 60)
42
12
0
0
0
9
0
0
0
5
Eff flow
L/sec (TGH)
234 (223)
* 38 ( 36)
16
13
230 (219)
46 ( 44)
20
9
255 (243)
28 ( 27)
11
5
In1 HjO Press.
Kg/cm^(#/in.2)
3.1 (44 )
0.5 ( 6.6)
15
13
3.2 (46 )
0.2 ( 2.6)
6
9
3.2 (46 )
0.2 ( 3 )
7
5
Eff
pH
7.1
0.2
__ซ
13
7.0
0.1
--
9
7.0
0.1
--
5
*- Mot calculated.
-------
Table 62. CHARACTERISTICS OF EFFLUENTS WITH 2 HOUR CHLORINE RESIDUALS
Date
(1972)
July 21
27
31
Aug. 2
3
9
10
17
17
20
22
24
Oct. 9
10
Nov. 13
16
Add!
Cl
ppm
5.0
10.0
6.0
6.1
6.0
6.4
6. A
7.6
6.1
5.6
5.4
5.4
5.2
6.4
7.1
6.0
Lions
NaUH
Kg/day
98
98
73
82
82
82
82
82
82
82
82
82
65
59
--
72
tiff
pH
6.6
..b
6.7
6.8
6.9
6.8
6.8
7.2
7.2
..
7.3
--
7.0
7.2
7.7
7.1
Inject.
\\2<^ press.,
KR/cm2
4.9
4.9
4.2
5.1
4.6
4.9
5.1
4.
4.9
4.6
4.6
4.2
2.8
2.8
2,6
2.4
Variation* from mean3
Cl add.,
7.
-14
+72
+ 3
+ 5
+ 3
+10
+10
+31
+ 5
- 3
- 7
- 7
-10
+10
+22
+ 3
NaOH
add.. 7.
+22
+22
- 8
+ 2
+ 2
+ 2
+ 2
+ 2
+ 2
+ 2
+ 2
+ 2
-18
-26
..
-10
Eff pH,
units
-0.4
. .
-0.3
-0.2
-0.1
-0.2
-0.2
+0.2
+0.2
--
+0.3
-.
0
+0.2
+0.7
+0.1
Inject
HjO press., 7.
+17
+17
0
+21
+10
+17
+21
+17
+17
+10
+10
0
-33
-33
-38
-43
Cl resid,
ppm @
5 Min
1.2
..
2.8
3.3
1.8
2.0
2.0
3.8
3.2
4.0
2.7
2.3
2.0
2.6
2.7
2.4
2 Hrs
0.5
1.2
1.2
0.7
0.7
0.5
0.5
1.6
0.3
1.0
0.3
1.2
0.3
0.7
0.6
0.6
A Cl/2 hrs
ppm
0.7
--
1.6
2.6
1.1
1.5
1.5
2.2
2.9
3.0
2.4
1.1
1.7
1.9
2.1
1.8
% of
5 Min res
58
..
57
79
61
75
75
58
91
75
89
48
85
73
78
75
00
o
"Mean of samples with no 2 hour chlorine residual.
b -- Not determined.
-------
EFFECT OF CHLORINATION ON RECEIVING WATERS
Procedure
Coliform analyses were made on samples collected from the following
sites:
Cement Plant - On the South Santiam River upstream from the mill and
city effluent discharge points.
Mark Slough Bridge - 304 m (334 yd) downstream of mill discharge. The
slough may be 50 percent or more effluent depending on water flow
from an upstream dam.
Mark Slough Mouth - 1.22 Km (1334 yd) downstream at the entrance to
the South Santiam River.
Pipeline Crossing - 4.83 Km (3 mi) downstream on the South Santiam
River.
Sanderson's Bridge - 12.9 Km (8 mi) downstream.
Analyses for dissolved oxygen, pH and temperature were made at the
sampling site.
Coliforms
Prior to chlorination the mean coliform count was 5.7 million/100 ml
at Mark Slough Bridge and 4.2 million/100 ml at the mouth of the slough
(Table 63). Chlorination reduced concentrations but its effectiveness
was variable (Figure 41). For example on July 18 and 27 and on
August 24 coliform concentrations at the mouth of the slough were
similar to those found before chlorination. In contrast, during the
last few days of August, counts in the slough were reduced to levels
approaching those found in the river upstream from the mill discharge,
181
-------
Table 63. KFFECT OF CHUJfUNATlON ON RECEIVING WATERS. SUMHAKY OF DATA
Analysis
ฃH
Mean
RanRe
0 of tests
U.O., ppm
Mean
Kange
# of tests
Temp, ฐC.
Mean
Kange
* of tests
Cl reslcl, ppm
Mean
Range
it of tests
Collf/100 ml
X 1C3
Mc-an
Kn np/*
h of t'?sts
Samp 1 e
Ceirent plant
None
7.2
1
0
16.5
. 1
0
0.002
1
Chlor
7.44
6.9-8.2
14
10.5
10.0-11.4
11
18.3
13.7-23.0
13
0.92
0-3.6
9
0.003
0.001-0. 002
15
M.S. bridge
None
6.70
6.3-7.3
6
5.82
3.6-6.9
4
21.0
18.6-25.0
6
0
0
5
56.8
30-140
6
Chlor
7.11
6.7-7.6
14
7.00
4.7-9.0
12
??.o
16.0-26.4
14
0.27
0-1.1
10
5.27
0.005-54.0
15
points and treatment of effluent
M.S. mouth
None
6.83
6.4-7.4
6
2.45
0.4-5.4
4
22.2
21.3-24.3
6
0
0
5
42.5
13-110
6
Chlor
7.13
6.6-7.7a
15"
3.10
1.2-7.1
12
22.4
15.6-29.4
14
0.12
0-1.1
12
12.80
0.001-120
17
Pipeline crossing
None
7.10
1
0
16.8
1
0
0.230
\
Chlor
7.32
7.0-8.2
14
8.85
4.9-10.8
11
18.7
16.0-23.8
13
0.50
0-1.2
9
0.150
0.001-0.860
16
Sanderson's bridge
None
__b
0
0
0
0
0
Chlor
7.35
6.9-8.1
13
9.41
8.4-10.8
12
20.2
14.9-24.8
12
0.56
0-1.6
10
0.074
0.001-0.65
15
00
Is?
KxcLuding abnormal valur? of 4.6 on Juno 30.
Not determined.
-------
8-
CHLQR1NATION
CO
OJ
6-
CD
O
O
4-
2-
AT BRIDGE
AT MOUTH
SEE TEXT
5
a I i i'l i& ib A A Jo 3i
AUGUST
12 13 13 20 27 28 30 7 8 18 19 i 2
1972 JUNE
JULY
Figure 41. Effect of chlorination on concentrations of conforms in Mark Slough.
-------
between 100 and 1000 coliforms/100 ml. These and all other analytical
data are presented in Table IX, Appendix.
The occasions of poor chlorination performance were found to be due to
pump failures which allowed primary effluent to be discharged into the
slough. The relatively high sulfite content of this waste would
immediately inactivate chlorine residuals. When these periods of
abnormal operation are not considered, the reduction of coliforms in
the slough by chlorination was 96.0 percent. For the last 10 days of
normal operation, coliforms were reduced by 99.65 percent from pre-
chlorination levels.
The effects of chlorination were also seen in samples taken 3 miles
and 8 miles downstream from the mouth of the slough (Figure 42).
Changes in coliform concentrations in the river paralleled those found
in samples from the mouth of Mark Slough. High coliform populations
again were due to the inactivation of chlorine by influent discharged
to the slough.
During the last 7 days of the tests coliform concentrations were
greatly reduced in the slough by effective chlorination. This was
reflected by similar changes in the river. From August 29-31 coliform
levels in the river at both downstream sampling points were approximately
the same as those found upstream from the slough, 50-170 coliforms/100 ml
(Table IX, Appendix).
It was interesting to find that during periods of ineffective or
marginal chlorination there was approximately a 2 log unit difference
between coliform populations in the slough and river. This approximates
the effluent dilution rate in the river and indicates that the effluent
is the major source of coliforms. As chlorination became more effective,
the populations became closer in number. Near the end of the test,
184
-------
00
Ul
8_
CO
01
o
=i 4-
o
o
2-
A MOUTH OF SLOUGH x 3 miles DOWNSTREAM
O 8 miles DOWNSTREAM
I
I
18 19 21 25 27 31
(1972) JULY
3 8 11 16 18 24
AUGUST
I
29 30 31
Figure 42 Reduction of coliform concentrations in the South Santiam River
due to chlorination of secondary effluent.
-------
coliform concentrations were equivalent in the slough and river showing
that effluent discharge was not significantly affecting the coliform
population in the river.
Dissolved Oxygen
As effluent is discharged from the secondary treatment ponds it absorbs
oxygen by falling in thin films over weirs and by turbulence. At the
point of discharge into the slough it may contain 7 to 8 ppm D.O. As
the waste flows down the slough, D.O. concentrations are reduced by
the activity of microorganisms. In laboratory experiments with undiluted
effluent, the rate of oxygen uptake was found to be approximately
2 ppm D.O./hr (Table 37). In the slough the rate could be less than
this due to the effects of dilution water which spills over a dam
upstream from the point of effluent discharge. However, most of the
time the rate of oxygen uptake in the slough or the D.O. concentration
at the mouth of the slough can be used as an indication of the effective-
ness of chlorination. This is a field application of the laboratory
test, Oxygen Uptake Test, discussed in Section X. In this case, D.O.
measurements at the mouth of the slough provide a more convenient
index.
Under normal operating conditions the mean of 3 determinations, made
at the slough mouth before chlorination, (Table IX, Appendix) was 1.5
ppm with a range of 0.4-2.6 ppm. During chlorination the mean of 7
samples, taken during normal operation, was 4.5 ppm with a range of
3.0-7.1 ppm. The same conditions which affected coliform counts
affected D.O. levels. When influent flowed into the slough and
inactivated chlorine residuals, July 18, 27 and August 24, microbial
activity reduced D.O. concentrations to prechlorination levels (Figure
43). The reason for the low D.O. concentration on August 8 was not
determined but it coincided with an increase in coliforms (Figure 41).
186
-------
8-
00
CL
CX
o
X
o
Q
LU
O
00
00
6-
4-
2-
BEFORE
CHLORINATION
DURING
CHLORINATION
AT BRIDGE
AT MOUTH
SEE TEXT
I I
I
l 1
I i
15 20 27 2830
JUNE
7 8
18 19 21
JULY
25 27 31 38
16 18 24 29 30 31
AUGUST
Figure 43. Effect of chlorination on D. 0. in Mark Slough.
-------
D.O. measurements also proved to be a sensitive indicator of unusual
conditions occurring during secondary treatment. On June 20, prior to
chlorination, the D.O. concentration at the mouth of the slough was 5.4
ppm. This unusually high value was related to low effluent pH.
Measurements taken on June 21 showed that effluent from Pond 1 had a
pH of 5.6 and that from Pond 2, 4.8. Previous laboratory experiments
(Table 37) showed that oxygen uptake by secondary effluent in this pH
range was 32 percent less than at the usual pH of 7.0. The pH value
6.8 obtained at the mouth of the slough on June 20 is questionable.
Fluctuations of D.O. in the slough had their corolaries in the river.
Although the river 8 miles downstream consistently had more than 8 ppm
D.O., the times of lowest concentrations corresponded to those when
D.O. was lowest in the slough (Figure 44). D.O. levels 3 miles down-
stream were 7.7 ppm and 4.9 ppm on July 18 and 19, respectively. This
was considerably lower than found in the samples taken further
downstream. On all of the other sampling days D.O. concentrations were
the same at the 3 mile and 8 mile locations.
The reduction of D.O. in the river by effluent discharge is not due to
the low D.O. of the effluent per sฃ but rather to the large bacterial
population which caused it. The amount of D.O. decrease will depend
on the concentration of bacteria and the BOD of the diluted effluent.
ฃ5
Chlorination should have no effect on the pH of receiving waters
because of the small amount of chlorine used and the neutralization of
chlorine hydrolysis products with caustic. Any effects due to abnormal
chlorinating conditions were not detected. It was noted, however,
that factors upstream from the effluent discharge point had a. significant
effect on the pH of the river. For example, on July 21 and August 31
the pH of the river, measured at the cement plant, was approximately 8.
188
-------
10 -
A MOUTH OF SLOUGH X 3 miles DOWNSTREAM
O 8 miles DOWNSTREAM
8 J
o.
d.
X
O
O
O
CO
CO
6 _
4 _
2 -
18 19 21 25 27 31 3 8 11 16 18 24
(1972) JULY AUGUST
Figure44. Effect of chlorination of secondary effluent on D. 0.
concentrations in the South Santiam River.
189
-------
The pHs of effluent at the mouth of the slough were 7.2 and 7.4 on the
two days. Three miles and 8 miles downstream, the river reflected
the higher pHs found upstream of the effluent discharge (Table IX,
Appendix).
Chlorine Residuals
Positive tests for total residual chlorine were obtained for 3 out of
15 samples taken at Mark Slough Bridge and for 2 out of 15 from the
mouth of the slough (Table IX, Appendix). On these days positive
residuals also were found at the two downstream sampling points in the
Santiam River. There may not have been a cause and effect relationship,
however, as positive results were frequently obtained for samples
taken upstream from Mark Slough. This was at the Cement Plant site
which also was upstream from the Lebanon's City Sewage Treatment Plant,
a potential source of chlorine residuals. On four occasions positive
tests were found at the Pipeline Crossing and at Sanderson's Bridge
when no residuals were detected at the mouth of the slough. On August
8 and 11 total residual chlorine was found at Sanderson's Bridge but
none could be detected upstream at the Cement Plant site or at the
mouth of Mark Slough. The results indicate that factors other than
chlorine were responsible for the positive tests. The presence of
nitrite in the river water is one possible cause. Laboratory studies
(Table 55) showed that 0.066 ppm NO ~ in water gives a positive test
for total residual chlorine. Possible sources of nitrite would include
the application of inorganic fertilizers followed by leaching and/or
runoff. Under the proper conditions microorganisms can form nitrite
by reducing nitrate or by oxidizing ammonia.
These results again show that the tests for total residual chlorine
have to be interpreted with caution unless conditions are well defined.
190
-------
SECTION XII
FATE OF CHLORINE ADDED TO SECONDARY EFFLUENT
Mill trials have shown that the amount of chlorine required to provide
bactericidal activity in secondary effluents can be reduced by converting
molecular chlorine to hypochlorous acid and/or sodium hypochlorite
(Table 49). This is probably due to the greater reactivity of molecular
chlorine. However, effects of pH on other reactants may be involved.
For example, when molecular chlorine is used, effluent pH is lowered
by the hydrolysis products HCl and HOC1. This tends to repress the
ionization of lignosulfonates and perhaps make them more reactive.
Results from the mill studies also indicated that the reaction products
of chlorine and effluent may vary qualitatively with the form of
chlorine used. On July 21, 1972 (Table VI, Appendix) 5.0 ppm chlorine
with NaOH addition was more bactericidal than 17.5 ppm chlorine without
it, even though the latter provided higher concentrations of total
residual chlorine.
It is possible that a chlorine-lignosulfonate complex is formed, when
Cl is used, which releases active chlorine under acidic test conditions
but not at the neutral PH of chlorinated effluent.
Another possible reason for the lack of correlation between total
residual chlorine and bactericidal activity would be the oxidation of
ammonia to nitrite by molecular chlorine. This would lead to a false
191
-------
positive test for total residual chlorine. Laboratory tests (Table 55)
showed that 0.1 ppm N0_ in effluent would be sufficient for this.
Further studies on chlorine reactions were made with sodium hypochlorite,
as this form of chlorine is used in the modified mill treatment system.
ANALYTICAL METHODS
12
Amperometric titrations based on procedures described by Rebertus were
used to analyze for various species of chlorine. The methods are based
on the following characteristics of chlorine compounds:
a. Free chlorine (hypochlorous acid, HOC1) can be titrated with
standard phenylarsenoxide solution at pH 7. Addition of potassium
iodide (KI) is not required.
b. Monochloramine (NlUCl), but not dichloramine, reacts quantitatively
with KI at pH 7. The liberated iodine can be titrated with
phenylarsenoxide.
c. Dichloramine (NHCl-) at pH 4 oxidizes KI to I- which can be titrated.
By making successive titrations on the same sample, with addition of
appropriate reagents, the various forms of chlorine can be distinguished.
However, in this study with secondary effluents, separate titrations
were made to increase sensitivity and to minimize reaction times for
each chlorine species. With this technique an initial titration made
at pH 4 with KI present measures total residual chlorine which includes
HOC1, NH2C1, NHCl- and other forms of combined chlorine. Dichloramine
cannot be identified as such. The following equation summarizes the
relationships.
192
-------
Total Residual
Chlorine
- HOC1 -
NH2C1
NHC1 + Other Forms of
2 Comb. Chlorine
The test conditions, addition of NaOCl to pH 7 effluent, would favor
the formation of NH2C1 over NHClg. At this pH, equilibrium reactions
also would result in predominance of the monochloramine. If no NH^Cl
was detected in a sample it was assumed that NHC1_ also was absent
and that the nature of combined chlorine would remain undefined.
Analyses were made with a Metrohm Herisau E436 Potentiograph and
E436D automatic titrator (Brinkmann). A platinum foil working electrode
and calomel reference electrode were used with a polarizing voltage of
0.1 V. This and other instrument settings are given in Table 64.
Sensitivity of the methods for the various forms of chlorine was 0.04
ppm.
Table 64.INSTRUMENT SETTINGS FOR
rm/)RTNE DETERMINATIONS
Control
marking3
Stop
Calibr. pH
Epol.
uA/50 mV
Ipol.
0 0 (Titration)
Temp. ฐC.
mV x 100 comp.
PH/ 250 mm
mV/
dE/dt
Dial
setting
0
OM
I
-i-
0
10
50
Epol.
.
For Metrohm Herisau E436 Potentiograph.
193
-------
FORMATION AND STABILITY OF VARIOUS FORMS OF CHLORINE
Sodium hypochlorite was added to secondary effluent to provide initial
chlorine concentrations of 6 to 12 ppm. Chlorine analyses were made
at intervals from 5 minutes to 4 hours. Positive tests for total
residual chlorine were obtained for all samples. Residuals persisted
for approximately 15 minutes when the initial chlorine concentration
was 6 ppm (Table 65). At higher application rates, residuals were
found after 1 hour but not after 4 hours reaction time.
Table 65. RECOVERY OF CHLORINE ADDED TO
SECONDARY EFFLUENT
Chlorine
added,
ppm
6
8
10
12
Reaction
time,
minutes
0 to 5
15
30
60
240
0 to 5
15
30
60
240
0 to 5
15
30
60
240
0 to 5
15
30
60
240
Chlorine recovered, ppm
Free Cl
(HOC1)
-0.04
0.04
-0.04
- 0.04
0.04
-0.04
0.04
'. 0.04
< 0.04
<- 0.04
' 0.04
< 0.04
-,0.04
< 0.04
< 0.04
c 0.04
<- 0.04
<_ 0.04
<-- 0.04
0.04
Mono-
chloramine
' 0.04
^ 0.04
c^0.04
< 0.04
c. 0.04
< 0.04
<-. 0.04
^0.04
< 0.04
0.04
0.06
,,0.04
< 0.04
0.04
0.04
0.16
. 0.04
* 0.04
_0.04
^0.04
Total
residual
0.31
0.08
< 0.04
-0.04
^-0.04
1.24
0.52
0.46
0.12
^ 0.04
1.23
0.93
0.58
0.27
^ 0.04
1.66
1.45
1.03
0.91
^0.04
194
-------
Free chlorine (HOC1) was not found in any of the samples. Monochloramine
was detected in samples receiving 10 and 12 ppm chlorine but not in
those with less chlorine. The chloramines were not stable. They
could not be detected after 15 minutes.
Chloramine reactions were studied further. First it was found that
when sodium hypochlorite was added to an aqueous solution of NH, at
pH 7 the only active form of chlorine detected was monochloramine. In
other tests monochloramine was added to secondary effluent to provide
an initial concentration of 10 ppm chlorine. Titrations made after
10 minutes reaction time showed no trace of the chloramine.
The results show that both free chlorine and monochloramine react
rapidly with secondary effluent to produce a form of combined chlorine
which is more stable than chloramines, but gradually reacts completely
with effluent. It appears very unlikely that chlorination under the
conditions described would produce chloramine residuals in secondary
effluent.
DURATION OF BACTERICIDAL ACTIVITY
The same source of effluent and chlorinating solution used in the
preceeding tests were utilized in microbiological studies. Effluent
was treated to contain the same initial chlorine concentrations as
before. The effects of chlorine on microorganisms were evaluated
with the Oxygen Uptake Test, Motility Test and by enumerating coliforms
and other bacteria. For the last two tests residual chlorine was
inactivated with sodium thiosulfate. Results are summarized in Table 66.
Effect on Oxygen Uptake
The rate of oxygen uptake by secondary effluent was inhibited by all
concentrations of chlorine tested. Although no total residual chlorine
195
-------
Table 66. EFFECT OF TOTAL RESIDUAL CHLORINE ON MICROORGANISMS
Analysis and
Cl addition
Total resid. cla
Cl added, ppm
0
6
8
10
12
Colif/100 ml X 103
Cl added, ppm
0
6
8
10
12
Total bact/100 ml X 10'
Cl added, ppm
0
6
8
10
12
Motile spir. /field
Cl added, ppm
0
6
8
10
12
Effluent D.O.
Cl added, ppm
0
6
8
10
12
Reaction time
Start
ฐ ..b
80.0
80.0
80.0
80.0
80.0
280.0
280.0
280.0
280.0
280.0
1.0-10
1.0-10
1.0-10
1.0-10
1.0-10
8.4
8.6
8.6
8.4
8.8
10 min
0
0.20
0.90
1.10
1.60
50.0
< 0.0001
< O.OOOT
^ 0.0001
< 0.0001
280.0
36.0
4.8
13.0
1.4
1.0-10
1.0-10
0
0
0
7.6
8.2
8.4
8.2
8.6
30 mln
0
-------
could be detected after 4 hours, the inhibition continued for 24 hours.
In all cases there was a linear decrease in D.O. concentration with
time (Figure 45). These results suggest that portions of the total
bacterial population were killed rapidly by chlorine and that the D.O.
uptake reflected the activity of the remaining viable bacteria.
Effect on Reproduction
Within 10 minutes coliform concentrations were reduced to less than
100/100 ml by all concentrations of chlorine. Apparently all coliforms
were killed by 12 ppm as none could be detected after 24 hours. For at
least 20 hours of this incubation period there was no total residual
chlorine which could act as an inhibitor. At lower levels of chlorine,
coliforms grew during the 24 hour period but final concentrations were
only small percentages of those present before chlorination. This
may have been due to growth of a very small number of survivors which
utilized nutrients leached from killed bacteria. Results were similar
with the total bacterial population but complete kill was not attained.
Effect on Motility
Results from the Motility Test correlated with those from MF analyses
for coliforms. Both procedures showed that 6 ppm Cl was effective.
The Motility Test can be made more demanding by reducing the contact
time from 30 minutes to 10 minutes. As shown in Table 66, with the
shorter time, 8 ppm chlorine was required to stop motility.
The effect of time on the bactericidal activity of chlorine residuals
was evaluated further using the following procedures:
197
-------
VO
00
TOTAL RESIDUAL CHLORINE PRESENT
NO RESIDUAL CHLORINE DETECTED
8-
E
a
a
CD
>-
S
a
o
to
00
6-
4-
i i i i \
INITIAL
CHLORINE
ppm
12
JL
8
TIME. hnur<;_
Figure 45. Effect of total residual chlorine on oxygen uptake by secondary effluent.
-------
a. To obtain a concentrated suspension of bacteria, a sample of
secondary effluent was centrifuged for 5 minutes at 9750 xg. The
supernatant was decanted and the sedimented bacterial cells were
resuspended in 1 percent of the original effluent volume.
b. The supernatant from step (a) was the source of cell-free effluent.
c. Sodium hypochlorite was added to cell-free effluent to provide an
initial chlorine concentration of 10 ppm. At intervals ranging from
30 seconds to 2 hours, two 100 ml samples were taken. One sample was
analyzed for total residual chlorine. The other sample was inoculated
with 1 ml of the bacterial suspension.
d. Uniform, 30 minute reaction times were allowed for the inoculated
samples. Sodium thiosulfate was then added to inactivate any residual
chlorine. After recovery periods of approximately 30 minutes, the
concentrations of motile spirilla were determined by microscopic
observation.
In summary the procedure provided for different reaction times between
chlorine and effluent, then uniform 30 minute reaction times between
chlorine residuals and bacteria.
Results showed that the chlorine residuals which were present in
effluent after reaction times of 30 seconds to 1 hour completely
stopped bacterial motility or greatly reduced it (Table 67). After a
reaction time of 2 hours, residual chlorine was still present in the
effluent, however the residual did not inhibit bacterial motility.
This lack of bactericidal activity could have been due either to a
qualitative change in the nature of the residual or to a quantitative
decrease to a concentration below the toxic threshold.
199
-------
Table 67. STABILITY AND BACTERICIDAL ACTIVITY OF
TOTAL RESIDUAL CHLORINE
Reaction
time3
0
30 Seconds
5 Minutes
30 Minutes
1 Hour
2 Hours
Total residual
chlorine,
ppm
0
4.0
3.7
3.4
2.4
1.5
Motile spirilla
per field after
30 minutesb
1-10
0
0
0.01-0.10
0
1-10
aReaction time between chlorine and cell-free effluent,
"After 30 minutes in the presence of the total resid.
chlor. concentrations shown in the middle column.
When considered along with the results from previous tests, these
findings bring up some interesting questions concerning the nature of
chlorine residuals. Arnperometric titrations (Table 65) showed that
the active forms of chlorine, hypochlorous acid and the chloramines,
do not persist for more than 15 minutes in effluent treated with 6 to
12 ppm of chlorine. Yet, the total chlorine residual which remains
exhibits considerable activity for a relatively long time. This has
relevance to the toxicity of residuals in receiving waters and possibly
to the development of new types of germicides.
200
-------
SECTION XIII
FISH TQXICITY OF CHLORINATED EFFLUENTS
STATIC LABORATORY TESTS
Procedure
Fish were kept in a 10 gallon aquarium and fed daily until 4 days
before testing. Then they were transferred to wide mouth, 2 1 assay
jars and feeding was discontinued. The jars contained 1-2 inch layers
of coarse aquarium gravel and carborundum air stones for aeration when
required. Test materials were added to measured water volumes in the
iars and the contents were mixed by gentle swirling. Test procedures
3
were based on those described in Standard Methods. Unless noted
otherwise the duration of the tests was 96 hours.
Tests with Gambusia
Preliminary tests with fresh water minnows (Gambusia sp.), showed that
chlorinated effluent was not toxic in concentrations up to 10 percent
(v/v), the highest level tested. For these experiments sodium hypo-
chlorite was added to effluent to provide an initial chlorine concentra-
tion of 10 ppm. After a reaction time of 15 minutes, aliquots of
chlorinated effluent were added to the assay jars which contained 4
fish each.
Tests with Guppies CLebistes reticulatusj
Aerated Effluent - Gambusia became unavailable so further testing was
done with guppies. In the first experiment effluent was treated to
201
-------
obtain an initial chlorine concentration of 10 ppm. After aging for
two hours, the chlorinated effluent was aerated mechanically and
transferred to assay jars. Higher concentrations of chlorinated
effluent were used than in the preceeding experiment, to obtain a
TL 50 value. This is the concentration of a toxic material which
3
permits survival of 50 percent of the fish. Samples were aerated
continuously with compressed breathing air.
Results (Table 68) showed that TL 50 values were in the range of 40 to
63 percent for both the chlorinated effluent and for unchlorinated
controls. Other data indicated that the chlorinated waste was slightly
more toxic. At concentrations of 10, 16, 25 and 40 percent, one out
of five fish died in chlorinated effluent but not in the controls.
The chlorinated effluent used in the test had received a bactericidal
concentration of chlorine, as shown by a decrease in coliform concen-
trations from 160 million per 100 ml to less than 100 per 100 ml
(Table 68).
Non-Aerated Effluent -- A similar experiment was made with no aeration.
The toxicity of both chlorinated and unchlorinated effluent was less
than when the samples were aerated. Only 1 out of 5 fish was killed
in 63 percent treated or untreated effluent (Table 69). In aerated
samples all fish were killed by this concentration (Table 68). There
was an indication that the chlorinated effluent was slightly more
toxic as 1 fish died in 50 percent and 2 fish died in 40 percent
chlorinated effluent. There was no mortality in the controls at these
effluent concentrations.
The chlorinated effluent used in the test had received a bactericidal
concentration of chlorine, as shown by a decrease in coliform concen-
trations from 10 million per 100 ml to less than 100 per 100 ml
(Table 69).
202
-------
Table 68. EFFECT OF CHLORINAT10N ON THE TOXICITY OF SECONDARY EFFLUENT
TOWARD GUPPIES IN AERATED SAMPLES
Treatment
of
effluent
Water control
None
Chlorinated
and
aged for
2 hours
Eff cone
in jars,
% (v/v)
0
2.0
10.0
16.0
25.0
40.0
63.0
100.0
2.0
10.0
16.0
25.0
40.0
63.0
100.0
Number of survivors
out of 5 after:
1 Day
5
5
5
5
5
5
3
-
5
5
5
5
5
0
2 Days
5
5
5
5
5
5
0
-
5
5
5
4
4
0
3 Days
5
5
5
5
5
5
0
-
5
5
4
4
4
0
4 Days
5
5
5
5
5
5
0
-
5
5
4
4
4
0
Coli forms/100 ml
X 105 after:
Starts
0
30
160
260
400
640
1000
1600
- 0.001
'0.001
0.001
0.002
0.002
0.005
0.006
1 Day
40
_-b
40
--
90
--
360
--
--
210
--
520
120
~ *~
N>
O
UJ
Calculated from initial concentration in 100% effluent.
-- Not determined.
-------
Table 69. EFFECT OF CHLORINATION ON THE TOXICITY OF SECONDARY EFFLUENT
TOWARD GUPPIES IN NON-AERATED SAMPLES
Treatment
of
effluent
Water control
None
Chlorinated
and
aged for
2 hours
Eff cone
in jars,
7, (v/v)
0
32
50
63
100
10
16
25
32
40
50
63
100
Number of survivors
out of 5 after:
1 Day
5
5
5
5
__b
5
5
5
5
5
5
5
- -
2 Days
5
5
5
5
5
5
5
5
5
5
5
4 Days
5
5
5
4
--
5
5
5
5
3
4
4
"" ~
Colifonns/100 ml
X 105 after:
Start8
0.001
32
50
63
100
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
1 Day
0.001
33
37
51
64
2.2
--
--
1.3
0.8
0.3
0.8
0.001
Calculated from initial concentration in 1007. effluent.
b -- Not determined.
-------
Effect of Aeration on Toxicity -- The cause of the greater toxicity of
the aerated samples was not determined. Possibly it was due to
differences in the effluent. The tests with aerated samples were made
on November 15, 1971 and non- aerated samples were evaluated one week
later with different waste.
Another possibility is related to the toxicity of NH^OH. Secondary
effluent from Lebanon contains approximately 140 ppm ammonia nitrogen
(NHปN). The amount which exists as NH., or NH.OH depends on the pH
of the effluent. It is the unionized form of NH-N which, in low
13
concentration, is toxic to fish. Ellis estimated that 2,5 ppm NH^
was lethal to goldfish. Aeration may purge CCL, produced by micro-
organisms, from solution and increase effluent pH and consequently
the concentration of NH.OH. pH measurements were not made during these
tests; however, in other experiments, removal of dissolved gasses by
reduced pressure increased effluent pH from 6.9 to 7.4. These values
will be used to illustrate the point.
10
From the disassociation constant of NH^OH,
Kb
= (NH4+)(ฐH") - 1.8 x 105
-------
Table 70. RELATIONSHIP BETWEEN EFFLUENT pH AND
CONCENTRATIONS OF NH/* AND NH,OH
Effluent
pH
6.0
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
6.9
7.0
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
7.9
8.0
8.5
9.0
pOH
8.0
7.9
7.8
7.7
7.6
7.5
7.4
7.3
7.2
7.1
7.0
6.9
6.8
6.7
6.6
6.5
6.4
6.3
6.2
6.1
6.0
5.5
5.0
(OH')
1.00 X 10'8
1.26 X 10'8
1.58 X 10'8
2.00 X 10~*
2.52 X 10"8
3.16 X 10'8
3.98 X 10'8
5.00 X 10'8
6.30 X 10~8
7.93 X 10"8
1.00 X 10'7
1.26 X 10'7
1.58 X 10'7
2.00 X 10'7
2.52 X 10"
3.16 X 10'7
3.98 X 10"7
5.00 X 10~7
6.30 X 10"7
7.93 X 10'7
1.00 X 10~ฃ
3.16 X 10~*
1.00 X 10ฐ
(NH4+)a
(NH/tOH)
1800
1430
1140
900
710
570
450
360
290
230
180
143
114
90
71
57
45
36
29
23
18
6
2
NH/OH, as NH,
7=
0.056
0.070
0.088
0.111
0.141
0.175
0.222
0.277
0.344
0.433
0.552
0.694
0.870
1.100
1.390
1.720
2.170
2.700
3.330
4.170
5.260
14.900
35.700
ppm
0.10
0.12
0.15
0.19
0.24
0.30
0.38
0.47
0.58
0.74
0.94
1.18
1.48
1.87
2.36
2.92
3.69
4.59
5.66
7.09
8.94
25.30
60.70
Eff cone, 7a
for 2.5 ppm NH0
100
100
100
100
100
100
100
100
100
100
100
100
100
100
100
86
68
54
44
35
28
10
4
afNV") - Kb - 1.8 X 10-"
(NfyOH (OH~) antilog--(14--pH)
bTotal anmonia concentration in effluent is approximately 170 ppm.
13
based on an average NH-, value for Lebanon effluent of 170 ppm and a
1 /
toxicity level of 2.5 ppm , show that an effluent concentration of
86 percent would be toxic at pH 7.5. An average of 215 ppm NH- was
13
found in Lebanon effluent during a 28 day period in 1969. At this
concentration, 40 percent effluent would be toxic at pH 7.5; 49 percent
at pH 7.4, and undiluted effluent would be toxic at pH 7.1. Actual
toxicity levels will vary according to a number of factors including
206
-------
the species of fish used. However these considerations show that
toxicity due to ammonia has to be considered when testing high
concentrations of Lebanon effluent.
Toxicity of Chlorine and Chloramine -- Sodium hypochlorite was added
to Santiam River water and to Santiam River water supplemented with
100 ppm NH.j. Amperometric titrations showed that chlorine was converted
to monochloramine in the latter case. Initial chlorine concentrations
were 10 ppm. The solutions were adjusted to pH 7 and various amounts
were added to assay jars containing guppies in Santiam River water.
The samples were not aerated. Monochloramine proved to be more toxic
than hypochlorous acid (Table 71). TL50 values for the two species
were approximately 0.40 ppm and 0.30 ppm (as Cl), respectively. A
concentration of 1.8 ppm of either compound killed some fish within
6 hours.
Table 71. TOXICITY OF HYPOCHLOROUS ACID AND
MONO CHLO RAMINS TO GUPPIES
Chlorine additions __|
Solution
None _
HOC1 in
water
pH 7.0
10 ppm Cl
NH2 Cl
in 100 ppm
NH4 Cl
pH 7.0
10 ppm Cl
Sol'n cone
in iars,
0
1.8
3.2
5.6
10.0
18.0
32.0
1.8
3.2
5.6
10.0
18.0
32.0
7
to
.ป
Cl in
assay
jars, ppm
0
0.18
0.32
0,56
1.00
1.80
3.20
0.18
0.32
0.56
1.00
1.80
3.20
Number of fish surviving
after
1 Day
4
4
4
4
3
0
0
'^
4
4
4
1
0
0
2 Days
4
4
4
4
2
0
0
4
4
3
1
0
0
3 Days
4
4
4
4
1
0
0
4
4
2
0
0
0
4 Days
4
4
4
4
1
0
0
4
4
2
0
0
0
207
-------
Comparison of Chlorine Toxlcity in Water and in Effluent In this
series of tests river water and effluent were treated to contain 10 ppm
initial chlorine. An expression which indicates the effect of effluent
on the toxicity of chlorine compounds can be obtained by comparing the
percents of chlorinated materials required to kill half of the test
fish within 4 days, TL50 values.
Cw
X
TL50 CE
In the expression above, ETI is the effluent toxicity index, Cw is
chlorinated water and CE is chlorinated effluent.
When HOC1 was added to water the ETI was less than 13:
ETI = T-rf x 100 = ^ 13
.-' oJ
This indicates that chlorine added to effluent is less than 13 percent
as toxic as chlorine added to water. Similar calculations for mono-
chloramine give an ETI value of less than ~l .
The values are conservative as TL50s were not reached with 63 percent
effluent (Table 69), the highest concentration tested. As discussed
earlier, with higher levels of effluent, factors other than chlorine
residuals have to be considered in relation to fish toxicity, e.g.,
unionized ammonia.
Inactivation of Chlorine Toxicity by Effluent
Toxic amounts of NaOCl were added to assay jars which contained fish
in river water, with and without additives. Samples were not aerated.
Interpretation of results from this experiment is difficult because
all of the fish died in the river water control within 4 days and the
addition of NH.C1 seemed to have a beneficial effect (Table 72). The
following results were obtained after 1 day of testing, when half of
the controls were alive.
208
-------
Table 72. INACTIVATION OF CHLORINE TOXICITY BY
EFFLUENT AND CHLORINATED EFFLUENT
Jar contents
Cl,
ppm
0
0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
NH3N,
ppm
0
100
0
0
0
0
0
0
100
100
100
100
100
100
Effluent, %
No chlor
0
0
0
5
50
0
0
0
0
5
50
0
0
0
Chlorin3
0
0
0
0
0
1
5
50
0
0
0
1
5
50
after
1 Day
2
4
0
0
4
0
0
1
0
0
4
0
0
1
2 Days
1
4
0
0
4
0
0
1
0
0
3
0
0
1
3 Days
0
3
0
0
4
0
0
0
0
0
3
0
0
1
4 Days
0
2
0
0
4
0
0
0
0
0
2
0
0
0
Number of fish surviving
treated with NaOCl to contain 10 ppm Cl and aged for 30 minutes.
Two ppm chlorine, in the presence and absence of NH, , was lethal to
guppies.
Chlorine toxicity was completely inactivated by 50 percent unchlorinated
effluent and somewhat reduced by 50 percent chlorinated effluent.
Lower concentrations of either material were ineffective.
The greater effectiveness of unchlorinated effluent may have been due
to the presence of low concentrations of reducing agents such as sulfite
which would react with chlorine before it would effect the fish. In
the chlorinated waste these compounds would have been oxidized and
reactions between chlorine and other effluent constituents were probably
too slow to protect the fish.
209
-------
The laboratory tests showed that chlorinated effluents have a low
degree of acute toxicity for fish. They also indicate that toxic
chlorinated phenolic compounds are not formed by chlorinating secondary
effluent. The procedures were limited in one important area. They
measured the toxicity of chlorine residuals for only a brief time.
Normally, residuals do not persist for longer than 2 hours and in the
static test are not replenished. Under actual conditions, if residuals
did persist, fish would be exposed to low concentrations of them
continuously. This situation was evaluated in field studies which are
described in the following section.
CONTINUOUS FLOW FIELD TESTS
Methods and Equipment
Apparatus was constructed to carry out 5 necessary procedures for
continuous toxicity tests: chlorination; aging of chlorinated effluent;
dilution of aged, chlorinated effluent; evaluation of fish toxicity;
and evaluation of bactericidal activity.
Chlorination Toxicity tests were started before a reliable mill
chlorination procedure was developed. For the first two trials
secondary effluent was treated with commercial sodium hypochlorite to
obtain initial chlorine concentrations of 10 ppm. A photograph of the
equipment used to do this, and to accomplish subsequent procedures, is
shown in Figure 46. A schematic is presented in Figure 47. Effluent
and a stock solution of sodium hypochlorite, at appropriate flow rates,
were mixed in a funnel which imparted a swirling action. Further
mixing occurred from gravity flow to the mix box. Details of this and
other procedures are given in the section APPARATUS AND METHODS.
When full scale continuous chlorination was in effect mill chlorinated
effluent was pumped to the mix box and the above procedure was not used.
210
-------
Figure 46. Apparatus for evaluating toxicity
of chlorinated effluents.
211
-------
EFFLUENT
NaOtl
WEIR
EFFLUENT
DELIVERY
BOX
MIX BOX
v\
* * *
WEIR
^EXCESS TO SEWER
AGING BOX
LUENT-
MP
EXCESS TO
SEWER
EXCESS TO SEWER
EFF.
HEAD^^
BPX\ !? /
WATE
HEAD
ROX
> II
RY
ii
1
f \
^
V
1
_\
ป>
i i /
V
*
1
t \
_^_ซM
S
7
H
t
1
^_\
r4
i /
V
1
(
L^
a
u
V*
i
1
IJOT
WEIR
*-c
:H
FISH
CHANNELS
aV
TO SEWER
Figure 47. Schematic of apparatus for evaluating
toxicity of chlorinated effluents.
212
-------
Reaction products of chlorine and effluent should be similar or the
same for the two chlorination methods. In the modified mill procedure
Cl? is converted to NaOCl and/or HOC1.
Aging of Chlorinated Effluent --An aging box was constructed in the
form of a labyrinth (Figures 46 and 47). Each of the eight channels
had a capacity of 454 1(120 gal.) which was equivalent to a retention
time of 20 minutes in these experiments. Since the channels were
2.44 m (8 ft) long, each 0.305 m (1 ft) represented a retention time
of 2.5 minutes. The aging box was calibrated on this basis. Any
retention time up to 160 minutes could be obtained by placing the
effluent pump inlet at the appropriate location in the aging box.
Mlution of Aged Chlorinated Effluent -- Chlorinated effluent was
pumped from the aging box to the effluent headbox (Figures 46 and 47)
at a rate slightly exceeding that required for the next stage. This
provided a constant head. Effluent was transferred to a riffle section
leading to the fish channels by means of adjustable flow delivery
tubes. River water from the water headbox also flowed to the riffle
area where it mixed with the effluent. Desired water flow rates were
obtained by adjusting V-notch weirs.
Evaluation of Fish Toxicity -- The procedures described in Standard
Methods3 were followed. The liquid flow rate to each of the fish
channels, which were 6.1 m (20 ft) long, was maintained at 0.631/sec
(10 gal./min). This provided a velocity of 2.0 cm/sec (4 ft/min).
For the first two experiments 10 steelhead trout were used per channel.
For the next 5 trials sockeye salmon were used at the rate of 20 per
channel.
Evaluation of Bactericidal Activity -- Coliforms in chlorinated effluent
were enumerated by the MF method. In addition, the Oxygen Uptake test
213
-------
was used to evaluate the effect of chlorination on the total bacterial
population. Normally, unchlorinated secondary effluent takes up
dissolved oxygen at the rate of 2 ppm/hr (Figure 22). As shown earlier
(Table 35) , inhibition of this rate by 64 percent or more indicates
that coliforms have been reduced to acceptable levels. The aging
box provided the means for making this a very rapid field test. By
taking D.O. measurements at two points a known distance apart,
consequently a known time interval apart in the calibrated channels,
the rate of oxygen uptake by chlorinated effluent can be calculated as
can the percent inhibition of the normal rate.
Results
Summary -- Seven toxicity tests were made. Since they differed in
one or more respects they will be discussed individually. However, a
summary of the more important data for all of the trials is given in
Table 73. The results showed that secondary effluent which was
chlorinated sufficiently to kill coliforms was not toxic to sockeye
salmon, providing the effluent was aged for two hours and diluted to
final concentrations of 20 percent or less. This is approximately 20
times the maximum effluent concentration estimated for the South
Santiam River.
Experiment 1 -- Within 1 day all of the test fish, steelhead trout,
were killed by 50 percent chlorinated effluent and by 67 percent
unchlorinated effluent (Table X, Appendix). A 50 percent concentration
of the latter showed no toxicity during the 1 day test. In this trial
sodium hypochlorite was added to provide an initial chlorine concentra-
tion of 10 ppm. However the effluent line to the mix box became
partially plugged. For a time effluent flowed at about half of the
normal rate while chlorine addition rates were normal. This increased
the initial chlorine concentration to approximately 20 ppm which was
double the desired concentration.
214
-------
Table 73. CONTINUOUS FLOW FISH TOXICITY TESTS. SUMMARY OF DATA
Measurement
Starting date (1972)
Duration of test (days)
Eff cone tested, %
Control
Chlorinated
Fish species (no. /channel )
Initial chlor cone in eff, ppra
Safe cond no toxic effects
Control eff
Eff cone, 7ซ
Time, days
Chlorinated eff
Eff cone, %
Time, days
Toxic conditions
Control eff
Eff cone, %
Time, days
Fish killed, %
Estimated TL50, 7.
Chlorinated eff
Eff cone, %
Time, days
Fish killed, "/,
Estimated TL50, 7,
Bactericidal activity of Cl
Coliform reduction, ฐL
Inh of 0_ uptake, U
Cl resid in eff headbox, ppm
1
April 3
1.0
50, 67
50
SH (10)
10.0
50
1.0
--
--
67
1
100
58
50
1
100
20
Not
Present
0
"720
--
--
0
4
Aug. 7
4.0
None
5-20
SS (20)
5.4-6.4
--
--
20
4
--
--
--
--
Not
Present
0
720
99.996
90
0-0.7
5
Aug. 14
4.0
None
5-20
SS (20)
4.4-6.3
_-
--
10
4
--
--
--
--
20
3
5
720
799.999
65
0-0.8
6
Aug. 20
4.0
None
5-20
SS (20)
3.9-5.4
_-
--
20
4
--
--
--
--
Not
Present
0
>20
99.999
89
0-0.6
7
Aug. 20
4.0
None
5-20
SS (20)
4.5-5.0
-_
--
20
4
-_
--
--
--
Not
Present
0
^20
99.999
88
"
aSH = Steelhead Trout;
b -- Not determined.
SS = Sockeye Salmon.
-------
Experiment 2 -- Conditions were the same as for the previous test --
small scale chlorination to obtain an initial concentration of 10 ppm
Cl; a 1 hour aging time for chlorinated effluent and the use of 10
steelhead trout per channel. In this trial 60 percent of the fish
were killed in 20 percent chlorinated effluent within 1 day and by
the end of the test there was significant toxicity at the 10 percent
level (Table XI, Appendix). Unlike previous results, 50 percent
unchlorinated effluent was quite toxic. It killed 70 percent of the
fish within 1 day and all of them within two days.
The relatively high degree of toxicity of the wastes may have been
partially due to the high pH of river water and its mixtures with
effluent. In the case of unchlorinated effluent, toxicity would be
related to the concentration of unionized ammonia. From the information
in Table 70 and a pH value of 7.6 for 50 percent effluent in this
experiment it can be calculated that the unionized ammonia concentra-
tion would be 1.8 ppm. In the previous experiment 50 percent effluent
at pH 7.2 would have an NH_ concentration of only 0.74 ppm.
High pH values also would increase the concentration and stability of
chlorine residuals in effluent. Evidence for this was the essentially
complete coliform kill, the almost complete inhibition of oxygen uptake
and the presence of chlorine residuals in the effluent headbox and in
the fish channels. Total residual chlorine was consistently detected
in channels containing 20 percent or more of chlorinated effluent. In
2 out of 3 tests it was found in 10 percent effluent and on one occasion
residuals were apparent in the channel containing 5 percent effluent.
Experiment 3 For experiments 3 through 7 effluent from full scale
mill chlorinatiou was used and the aging time was increased to 2 hours.
216
-------
Results from experiment 3 (Table XII, Appendix) showed that aging was
necessary to detoxify chlorinated effluent. Twenty percent unaged
waste killed 25 percent of the fish within 3.5 hours and all of them
within a day. After aging for 2 hours no toxicity was found during
the 2 day test period. Equipment failure caused a premature end to
this trial
Experiment 4 -- No toxicity was found for 20 percent chlorinated
effluent, the highest concentration tested, during the 4 day test
period (Table XIII, Appendix). Chlorination was effective as shown by
the consistent, high degree of inhibition of oxygen uptake and reduction
of coliforms to less than 100 per 100 ml. Initial chlorine concentrations
in this and the succeeding trials were considerably less than in the
first two experiments where the small scale chlorinator was used to
provide chlorine levels of 10 ppm. The treatment used in this series
of tests was 113 Kg/day (250#/day) of chlorine and 82 Kg/day (180
#/day) of NaOH, a combination which proved effective in numerous tests
(Table VIII, Appendix).
Experiments 5-7 -- Results from these 3 experiments (Tables XIII-XV,
Appendix) were essentially the same as described for experiment 4.
Chlorination was effective in killing coliforms and 20 percent
chlorinated effluent had no adverse effects on sockeye salmon during
4 day test periods.
217
-------
SECTION XIV
EVALUATION OF MISCELLANEOUS BACTERIOCIDES
COMPARISON OF CHLORINE DIOXIDE AND SODIUM HYPOCHLORITE
Stock solutions of chlorine dioxide (CIO ) and sodium hypochlorite
(NaOCl) were prepared to contain 1000 ppm active chlorine. Aliquots
were added to secondary effluent to provide initial chlorine concentra-
tions of 2-10 ppm. After 30 minute contact times portions of the
samples were analyzed for total residual chlorine. Other portions were
treated with sodium thiosulfate to inactivate any residual chlorine
then examined microscopically to determine the effect of treatment on
bacterial motility.
It was found that C10ป at every concentration tested produced total
chlorine residuals. The concentrations after 30 minutes were from
25 to 43 percent of added chlorine (Table 74). There was however no
effect on bacterial motility. In contrast, 6 ppm chlorine, added as
NaOCl, did not produce a 30 minute chlorine residual however it
stopped motility completely.
The reason for the lack of correlation between positive tests for
chlorine residuals and the absence of bactericidal activity with CKL
was not determined. Chlorine dioxide is a strong oxidizing agent. It
is possible that it oxidized some of the NH, in effluent to N0ซ which
in turn would give a false positive test for total residual chlorine.
218
-------
Table 74. COMPARISON OF CHLORINE DIOXIDE AND SODIUM HYPOCHLORITE
Cl added
as
Control
Chlorine
dioxide
Sodium
hypochlorite
Initial Cl
c one , ppm
0
2
4
6
8
10
2
4
6
8
10
30 Min Cl resid
ppm
0
0.5
1.4
2.1
3.3
4.3
0
0
0
0.9
0.5
7o of ini
25
35
35
41
43
0
0
0
11
5
Motile spirilla
j>er field @ 30 min
1-10
1-10
1-10
1-10
1-10
1-10
1-10
0.1-1.0
0
0
0
Formaldehyde and Paraformaldehyde
A Formalin solution containing 37 percent formaldehyde, 15 percent
methanol and 48 percent water was diluted in water to obtain stock
solutions. Aliquots of these were added to secondary effluent. After
30 minutes, samples were examined microscopically to determine effects
on bacterial motility. Results from these screening tests showed that
effective concentrations were between 10 and 100 ppm. Controls
containing 10,000 ppm methanol had no adverse effect on motility.
Similar tests showed that 100 to 1000 ppm paraformaldehyde were
required to stop motility.
Hydrogen Peroxide
Commercial, 20 percent hydrogen peroxide (H^) was diluted and
evaluated as described for the preceeding experiments. A concentration
of 2000 ppm H202 stopped bacterial motility in 15 but not in 5 minutes;
a concentration of 1000 ppm was ineffective during a 30 minute test
period.
219
-------
Ozone (0_)
A Welsbach Model T-23 Laboratory Ozonator was set up at the mill site
and operated on tank oxygen. The amount of ozone produced was measured
by sparging output gasses into 2 percent potassium iodide (KI)
contained in two traps connected in series. Iodine produced by the
oxidation of KI was measured by acidic titration with 0.025 N Na_S?0,,
to a colorless starch end point. Ozone production were calculated
using the following formula:
60
0- Prod, ml N of ., Trap Vol
mg/hr Thio X Thio X X Samp Vol X Time, min
To ozonate secondary effluent the sparger was placed in the vertical
section of a 3.8 cm (1.5 in.) O.D. rubber hose carrying the waste.
From measured ozone production rates and effluent flow rates initial
ozone concentrations were calculated. Reactions between effluent and
ozone were monitored by smelling the continuously treated waste. Since
ozone at concentrations of 0.1 ppm or less can be easily detected by
14
odor, the absence of its aroma was considered to be evidence that
most if not all of the applied ozone had reacted with effluent.
In a typical experiment ozone output was found to be 525 mg/hr. Effluent
flow through the hose was adjusted to 1140 L/hr (5 gal./min). The
ozone outlet with the sparger was then positioned in the effluent
stream. Under these conditions the initial ozone concentration was
0.46 ppm. A sample of the ozonated effluent was taken, then the
effluent flow rate was reduced without changing the rate of ozone
production. Using this method initial ozone concentrations of 0.46 to
4.6 ppm were obtained. In this range no excess ozone could be detected
by its odor. No residual ozone was present. Analyses made on the
samples after 30 minute reaction times showed no significant effect on
bacterial motility and no reduction in concentrations of bacteria
(Table 75).
220
-------
Table 75. EFFECT OF OZONE ON BACTERIA
Ini 0-
cone, ppm
0
0.46
92
2.30
4.60
.1 ___
Ozone
res , ppm
0
0
0
0
0
Motile
spirilla/field
1-10
0.1-1.0
O.l-loO
0.1-1.0
0.1-1.0
Bacteria,
Total x 105
88
123
145
173
185
IIQQ ml
Colif x lO4"
36
36
42
28
45
At the highest application rate tested, 21 ppm, not all of the ozone
reacted with effluent. This may have been related to the velocity
of oxygen-ozone mixtures, rather than to saturation of reactive sites.
Gas flow at the high ozone production rate was 2.0 1/min compared to
0.4 I/tain at lower production rates. The high rate of ozone addition
did not stop bacterial motility.
221
-------
SECTION XV
REFERENCES
1. Water Quality Standards Criteria Digest. Bacteria. Environmental
Protection Agency. Washington, D.C. August 1972.
2. Plan for Implementation and Enforcement of Water Quality and Waste
Treatment Standards for the State of Oregon. State of Oregon
Department of Environmental Quality. March 1972.
3. Standard Method for the Examination of Water and Waste Water, 13th
Ed. Washington, D.C., Am. Pub. Health Assoc., 1970. 874 p.
4. Difco Manual, 9th Ed. Detroit, Michigan, Difco Laboratories, 1953.
p. 33-34; 248-249.
5. Staley, J. T. Prosthecomicrobiura and Ancalomicrobium: New
Prosthecate Freshwater Bacteria. J. Bact. 95:1921-1942, May 1968.
6. Poindexter, J. S. Biological Properties and Classification of the
Caulobacter Group. Bact. Rev. 2^(3):231-295, September 1964.
7. Pate, J. L. and E. J. Ordal. The Fine Structure of Two Unusual
Stalked Bacteria. J. Cell. Biol. 27/1):130-133, October 1965.
8. O'Neil, F. W., et. al. Pulp and Paper Science and Technology,
Vol. I, Libby, C. E. (ed.). New York City, McGraw-Hill, 1962.
p. 349
222
-------
9. White, Geo. Clifford. Handbook of Chlorinatioru New York, Van
Nostrand Reinhold Comp., 1972. p. 182-204.
10. Watkins, S. H. Bacterial Degradation of Lignosulfonates and
Related Model Compounds. J. Water Poll. Cont. Fed. 42(No. 2,
Part 2):R47-56, February 1970.
11. Handbook of Chemistry and Physics, 41st Ed. Cleveland, Chemical
Rubber Publishing Co., 1959-1960. p. 1739.
12. Rebertus, R. L. The Analytical Chemistry of Nitrogen and Its
Compounds, Part 1, Streuli and Averell (eds.). New York City,
Wiley-Interscience, 1970. p. 201.
13. Amberg, H. R., et. al. Aerated Lagoon Treatment of Sulfite Pulping
Effluents. Crown Zellerbach Corporation. Washington B.C.
No. 12040 ELW. Environmental Protection Agency. December 1970.
135 p.
14. Ellis, M. M. Detection and Measurement of Stream Pollution.
Bull. U.S. Bur. Fish. 48:365-437, 1937. From: Jones, J. R. E.
Fish and River Pollution. Washington, B.C., Butterworth, Inc.,
1964. p. 100-103.
15. Basic Manual of Applications and Laboratory Ozonation Techniques,
First Revision. Philadelphia, Welsbach Corp., No Year Given. 36 p.
223
-------
SECTION XVI
GLOSSARY
Anaerobic - Complete absence of oxygen.
Bactericidal Activity - Killing of bacteria.
Biological Chlorine Demand - The concentration of chlorine, in ppm,
required to reduce coliform bacteria to acceptable levels within a
specified time.
BOD - Biochemical Oxygen Demand.
Caustic - Commercial, technical grade sodium hydroxide (NaOH). Concen-
tration of NaOH is usually between 40 and 50 percent (w/w).
Colicidal Activity - Killing of coliform bacteria.
Coliforms - In this report the term coliforms means total coliform
bacteria. These are aerobic or facultative anaerobic, gram-negative,
non-spore forming, rod-shaped bacteria which ferment lactose at 35ฐ C.
within 24 to 48 hours, depending on the assay method.
EPA Unit - A pilot secondary treatment unit operated at the Lebanon
mill by personnel of the Environmental Protection Agency.
224
-------
Five (5) Minute Residual - Total residual chlorine found after a
contact time of 5 minutes.
Inactivation (of chlorine) - Elimination of the bactericidal activity
of chlorine residuals.
MF Coliforms - Coliform bacteria enumerated by the membrane filter
method of analysis.
MT Coliforms - Coliform bacteria enumerated by the presumptive, lactose
fermentation test using multiple tubes (5 in this study) for each
sample size tested.
- Trade name of lignosulfonate by-products manufactured by
Crown Zellerbach Corporation. AL and GL grades contain ammonia
lignosulfonates and KSL and LS contain sodium lignosulfonates.
Primary Treatment - A process for removing fibers and other particles
from wastes.
Secondary Treatment - A process for reducing the BOD of a waste.
Total Bacteria - All bacteria which produce colonies on a standard
plate count agar which is incubated aerobically.
Water Leg - A column of water flowing through a pipe which has a
section of relatively small diameter. The increased water velocity
in the constricted section produces a partial vacuum which can be
tapped to operate an evaporator.
225
-------
SECTION XVI
APPENDICES
Table No. Page
I Characteristics of Secondary Composite
Effluent During Parallel Operation 228
II Characteristics of Secondary Influent 233
III Characteristics of Wastes from Mill Secondary
Ponds and Small Scale Treatment Units 237
IV Characteristics of Effluents from Ponds 1
and 2 During Parallel Operation 246
V Effect of Mill Chlorination on Bacterial
Motility and on Coliform Concentrations 248
VI Effect of Caustic Addition on Activity of
Chlorine in Mill System 250
VII Effect of Ammonia Addition on Chlorine Activity
in Mill System 254
VIII Results from Monitoring of Full Scale
Chlorination 258
226
-------
Table No. PaSe
IX Effect of Chlorination on Receiving Waters 263
X Continuous Toxic ity Test with Steelhead Trout.
Experiment 1 266
XI Continuous Toxicity Test with Steelhead Trout.
Experiment 2 267
XII Continuous Toxicity Test with Sockeye Salmon.
Experiment 3 268
XIII Continuous Toxicity Test with Sockeye Salmon.
Experiment 4 ฐ"
XIV Continuous Toxicity Test with Sockeye Salmon.
Experiment 5 270
XV Continuous Toxicity Test with Sockeye Salmon.
Experiment 6 2?1
XVI Continuous Toxicity Test with Sockeye Salmon.
979
Experiment 7 *-"
INDEX
227
-------
Table I. CHARACTERISTICS OF SECONDARY COMPOSITE EFFLUENT
DURING PARALLEL OPERATION
Date
(1971)
Sept. 14
22
23
24
28
29
Time
a
--
--
--
_-
Monthly mean
S.D. from
monthly mean
S.D. from
project mean
Dec. 13
14
15
23
27
30
31
31
1635
1425
1040
0955
1545
1340
0955
0840
Monthly mean
S.D. from
monthly mean
S.D. from
project mean
pH
6.8
6.7
6.9
--
7.0
7.2
6.9
0.2
0.3
7.2
7.2
7.5
7.0
7.3
6.6
6.6
6.6
7.0
0.4
0.4
Temp
ฐC
24.0
24.0
--
22.5
--
23.5
0.9
0.9
13.0
13.0
13.5
14.0
12.5
12.0
--
13.0
0.7
11.5
so ,
PPm
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
BOD,
ppm
72
87
93
105
102
98
93
12
19
96
96
131
119
100
138
122
122
116
16
19
Bacteria/100 ml
Total
X 107
47
380
98
19
490
150
197
193
215
230
210
16
35
9
290
--
--
132
125
209
Colif
X 105
22
31
48
53
33
49
39
12
232
15
18
29
104
54
16
18
25
35
26
233
Colif,
% of
total
0.47
0.08
0.49
2.8
0.07
0.33
0.71
1.04
1.65
0.25
0.23
1.1
5.7
6.2
0.19
--
--
2.3
2.9
2.9
a -- Not determined.
228
-------
Table I (continued). CHARACTERISTICS OF SECONDARY COMPOSITE
EFFLUENT DURING PARALLEL OPERATION
Date
(1972)
Feb. 1
2
3
8
10
11
12
Time
a
_ _
__
1425
1155
1525
1130
Monthly mean
S.D. from
monthly mean
S.D. from
project mean
March 13
13
14
14
14
14
14
14
15
15
15
16
16
17
18
22
24
24
24
1525
1815
0840
1140
1340
1425
1515
1605
0935
1230
1610
0905
1650
0840
1143
1605
0855
1145
1730
Monthly mean
S.D. from
monthly mean
S.D. from
project mean
Ph
6.9
6.8
6.8
6.8
6.8
6.6
6.8
6.8
0.1
0.4
6.8
6.8
6.8
6.9
6.8
6.8
6.9
6.9
7.0
7.2
7.2
7.2
7.2
7.2
7.3
7.0
6.9
6.9
7.0
7.0
0.2
0.2
Temp
ฐC
14.5
14.0
14.5
18.0
18.5
18.7
18.7
16.7
2.2
7.7
20.9
20.9
20.4
21.3
21.4
21.6
21.4
21.4
21.5
22.7
23.1
23.0
24.5
22.5
21.8
21.3
20.8
20.0
20.1
21.6
1.1
2.2
so3,
ppm
--
--
--
--
__
--
--
--
--
..
--
--
--
--
--
--
--
-_
--
--
--
__
--
--
--
--
--
--
--
--
BOD,
ppm
163
192
190
162
177
177
182
178
11
78
121
121
121
121
121
121
121
121
105
105
105
99
99
99
86
95
105
105
105
109
11
12
Bacteria/100 ml
Total
X 10'
160
170
63
150
410
130
280
195
115
150
76
58
81
--
--
99
42
43
200
110
210
150
140
150
140
70
93
50
70
105
52
192~~
Colif
X 105
210
180
18
140
10
44
110
102
80
202
140
90
130
230
210
290
270
19C
140
130
100
20C
19f.
16C
90
400
440
340
470
222
117
121
Colif,
7, of
total
1.3
1.1
0.29
0.93
0.02
0.34
0.39
0.62
0.48
1.4
1.8
1.6
1.6
--
--
2.9
6.4
4.4
0.70
1.2
0.48
1.3
1.4
1.1
0.60
5.7
4.7
6.8
6.7
2.9
2.3
276
a -- Not determined.
229
-------
' Table I (continued). CHARACTERISTICS OF SECONDARY COMPOSITE
EFFLUENT DURING PARALLEL OPERATION
Date
(1972)
April 4
12
13
Time
Monthly mean
S.D. from
monthly mean
S.D. from
project mean
May 18
18
18
25
Monthly n
1030
1200
1430
1415
lean
S.D. from
monthly mean
S.D. from
prelect mean
June 8
9
12
13
13
14
15
20
27
28
29
30
1330
1045
1650
1050
1440
1435
1400
1405
1440
1310
1520
1230
Monthly mean
S.D. from
monthly mean
S.D. from
project mean
pH
7.4
7.2
7.3
0.1
0.3
6.5
6.6
6.8
7.3
6.8
0.4
6.8
7.0
6.6
6.6
6.6
6.6
6.2
5.6
7.2
6.8
7.2
7.0
6.7
0.4
--
Temp
ฐC
17.1
17.1
--
--
__
__
--
--
29.0
28.5
25.3
26.0
28.4
26.0
26.8
28.0
29.0
29.0
--
31.0
27.9
1.7
4.9
ppm
--
--
--
--
_-
--
_-
--
--
__
--
--
--
BOD,
ppm
109
91
111
104
11
11
132
132
132
137
133
3
32
98
98
91
91
91
83
89
88
92
98
86
86
91
5
17
Bacteria/100 ml
Total
X 107
150
130
31
104
64
230
680
460
510
550
115
346
470
170
700
360
460
410
410
460
--
1000
--
493
234
323
Colif
X 105
1300
90
210
533
667
751
810
710
1000
550
768
188
625
330
330
110
80
120
140
160
140
360
380
310
24
207
125
133
Colif,
% of
total
8.7
0.69
6.8
5.4
4.2
6.0
1.2
1.5
2.0
--
1.6
0.41
0.55
0.70
1.9
0.16
0.22
0.26
0.34
0.39
0.30
--
0.38
--
--
0.52
0.54
1.5
a -- Not determined.
230
-------
Table I (continued). CHARACTERISTICS OF SECONDARY COMPOSITE
EFFLUENT DURING PARALLEL OPERATION
Date
(1972)
July 5
6
6
7
7
8
8
8
10
11
11
18
19
21
25
27
31
Time
1145
0100
1445
1245
2015
0800
1540
2100
1600
1050
1210
1139
1030
1130
0730
1315
1515
Monthly mean
S.D. from
monthly mean
S.D. from
project mean
Aug. 3
8
11
16
18
24
29
30
31
1303
1327
0740
2025
0540
0635
1140
1610
1028
Monthly mean
S.D. from
monthly mean
S.D. from
project mean
pH
5.6
5.6
5.4
6.0
6.2
6.5
6.6
6.6
6.4
5.7
5.7
6.9
--
6.6
6.9
7.2
6.9
6.3
0.6
1.0
6.7
6.7
6.7
7.1
6.9
7.4
7.3
7.1
7.3
7.0
0.3
0.3
Temp
ฐC
29.0
29.0
28.0
28.0
28.0
27.1
26.6
26.6
--
27.3
27.3
31.0
30.2
31.6
27.7
--
29.9
28.5
1.6
5.4
29.3
32.4
28.4
27.1
25.4
28.1
30.8
29.9
28.7
28.9
2.0
6.1
so3,
ppm
__a
--
--
--
--
--
--
--
--
--
--
--
--
4.3
3.0
--
..
3.6
0.9
0.9
4.4
--
--
--
--
--
--
--
4.4
--
--
BOD,
ppm
93
89
89
89
89
93
93
93
84
84
84
74
91
106
105
75
84
89
8
19
79
94
81
78
87
73
93
95
91
86
8
23
Bacteria/100 ml
Total
X 10'
440
500
460
360
--
--
--
--
--
--
-_
--
.-
--
--
440
59
190
220
-_
--
--
540
--
695
850
515
564
235
391
Colif
X 105
150
52
50
16
26
24
22
22
700
90
132
72
28
3
7
340
590
137
209
240
560
14
7
3
4
1200
495
480
250
335
400
410
Colif,
7. of
total
0.34
0.10
0.11
0.04
__
_ _
__
__
__
__
-_
__
--
__
__
..
-_
0.15
0.13
2.0
2.5
--
--
0.01
--
0.71
0.56
0.49
0.85
0.96
1.5
a -- Not determined,
231
-------
Table I (continued). CHARACTERISTICS OF SECONDARY COMPOSITE
EFFLUENT DURING PARALLEL OPERATION
Date
(1972)
Sept. 19
20
21
22
26
Time
1603
0845
1230
0920
0912
Monthly mean
S.D. from
monthly mean
S.D. from
prelect mean
Oct. 5
6
7
9
10
11
13
16
17
18
19
24
26
31
1015
1700
1304
1333
1700
1104
1832
1400
1102
0938
1500
1500
1300
1600
Monthly mean
S.D. from
monthly mean
S.D. from
project mean
Nov. 6
8
13
1025
1730
0945
Monthly mean
S.D. from
nouthly mean
S.D- from
p'-'^ect mean
Project mean
Project S.D.
No. of Analyses
PH
7.0
6.1
6.4
7.0
7.0
6.7
0.4
0.6
6.9
7.0
7.0
7.0
7.2
7.0
6.9
6.9
7.1
7.1
7.0
7.0
7.0
7.0
7.0
0.1
0.1
6.8
6.8
6.9
6.8
0.1
0.3
7.1
0.5
104
Temp
ฐC
24.0
23.0
23.0
22.0
19.0
22.2
1.9
2.4
23.0
22.0
24.0
22.8
22.0
21.1
22.7
23.4
23.4
22.0
22.0
19.4
21.5
18.2
22.0
1.6
2.2
20.0
20.4
21.6
20.7
0.8
3.6
23.5
4.9
93
S03,
ppm
4.4
3.7
3.0
a
3.9
3.8
0.6
0.6
_.
4.9
3.4
3.1
3.0
3.0
3.9
3.3
3.1
2.8
3.6
3.3
3.4
3.4
0.6
0.6
4.3
3.7
3.2
3.7
0.6
0.6
3.6
0.6
22
BOD,
PPffi
157
122
112
112
95
120
23
28
114
114
93
99
99
104
97
106
106
78
81
95
80
93
97
12
15
92
126
130
116
21
24
106
25
107
Bacteria/100 ml
Total
X 107
94
87
100
91
280
130
84
191
220
410
360
130
360
310
350
240
120
91
210
320
600
640
312
164
166
320
240
1600
720
763
931
284
256
82
Colif
X 105
120
120
190
40
730
240
279
279
400
110
110
520
520
260
290
770
1000
1500
440
240
370
230
483
382
451
210
620
120
317
267
278
251
291
107
Colif,
% of
total
1.3
1.4
1.9
0.44
2.6
1.5
0.80
0.88
1.8
0.27
0.31
4.0
1.4
0.84
0.83
3.2
8.3
16.5
2.1
0.75
0.62
0.36
2.9
4.3
4.6
0.66
2.6
0.08
1.1
1.3
1.6
1.9
2.2
82
a -- Not determined.
232
-------
Table II. CHARACTERISTICS OF SECONDARY INFLUENT
Date
(1971)
Sept. 4
Time
1115
Monthly mean
S.D. from
monthly mean
S.D. from
project
Dec. 13
14
15
27
30
31
mean
1630
1950
1200
1520
1335
0730
Monthly mean
S.D. from
monthly mean
S.D. from
project
(1972)
March 13
13
14
14
14
14
14
14
15
15
15
16
16
17
18
22
24
24
24
mean
1530
1810
0810
1140
1340
1425
1515
1605
0915
1230
1610
1115
1655
0855
1143
1555
0900
1150
1735
Monthly mean
S.D. from
monthly mean
S.D. from
project mean
PH
8.7
8.7
--
--
8.4
8.4
9.0
8.3
7.2
9.5
8.5
0.8
1.9
5.4
3.6
3.8
9.0
6.0
__
__
- -
9.3
9.2
--
--
--
4.0
7.8
8.7
_.
--
6.7
2.4
2.4
Temp.
ฐC
__a
__
--
--
27.0
26.0
25.5
--
--
--
26.2
0.8
9.9
30.5
30.5
30.8
30.5
30.7
31.0
31.0
31.4
31.8
35.0
35.5
40.5
35.5
35.5
30.5
30.0
29.0
29.5
30.0
32.1
2.9
3.7
so ,
ppfi
--
--
--
..
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
BOD,
ppm
240
240
--
__
415
415
405
410
465
395
418
24
25
410
410
440
440
440
440
440
440
440
440
440
375
375
430
430
390
415
415
415
422
22
24
Bacteria
Total
X 10?
70
70
--
--
12
16
11
2
3
--
8.8
6.1
40
7
1
3
--
--
2
7
3
4
3
2
1
2
0.2
80
190
180
46
33
63
66
/100 ml
Colif .
X 105
4
4
--
--
26
34
42
4
8
4
20
17
825
160
10
70
200
68
29
60
90
160
34
2
38
9
18
7
1370
3300
4000
180
516
1150
1180
Colif.,
% of
total
0.06
0.06
--
--
2.2
1.5
3.8
2.0
2.7
2.4
0.9
19
23
10
23
--
14
8.6
30
40
11
1.0
--
9.0
9.0
35
17
17
22
3.9
17
11
11
a -- Not determined.
233
-------
Table IKcontinued) . CHARACTERISTICS OF SECONDARY INFLUENT
Date
(1972)
Aug. 3
8
11
16
18
24
28
29
30
31
Monthly n
Time
1300
1525
0730
2015
0530
0623
1835
1205
1700
0845
lean
S.D. from
S.D. from
project mean
Sept. 15
*
15
18
19
20
21
22
26
29
0945
1235
0810
1110
1115
0845
0830
0926
1145
Monthly mean
S.D. from
S.D. from
project mean
pH
_ซa
--
__
4.3
__
__
__
5.5
-_
4.5
4.8
0.6
2.7
4.2
8.8
9.0
4.2
3.2
3.4
7.2
4.2
4.2
5.4
2.3
2.8
Temp.
ฐC
37.5
46.0
40.0
40.0
41.0
35.0
__
41.0
32.0
36.0
38.7
4.1
6.3
35.0
37.0
35.0
40.0
40.0
36.0
32.0
31.0
33.0
35.4
3.0
3.5
S03,
PP">
83
250
234
83
--
--
--
125
155
81
83
..
--
--
269
230
58
104
--
165
100
104
BOD,
PPm
350
410
450
330
460
450
415
415
350
375
400
47
49
500
500
400
400
400
440
440
370
365
425
50
52
Bacteria/100 ml
Total
X 107
--
--
23
--
13
35
3
6
16
13
34
120
12
3
4
0.9
7
3
90
50
32
45
46
Colif.
X 105
3100
80
29
12
520
3300
660
1600
52
180
953
1280
1290
1400
1500
12
100
34
240
330
490
50
462
582
669
Colif.,
% of
total
*ซ
23
--
51
46
17
30
33
15
22
12
125
4.0
25
38
34
110
5.4
1.0
39
46
51
a Not determined.
234
-------
Table II(continued). CHARACTERISTICS OF SECONDARY INFLUENT
Date
(1972)
April 12
13
Time
__a
Monthly mean
S.D. from
monthly mean
S.D. from
project mean
June 8
9
12
13
13
14
15
20
28
Monthly n
1325
1130
1655
1055
1445
1425
1350
1545
1325
lean
S.D. from
monthly mean
S.D. from
project mean
July 8
8
18
19
21
25
27
31
Monthly i
1532
2035
1143
1320
1500
0720
1450
1555
nean
S.D. from
monthly mean
S.D. from
project mean
PH
8.5
4.0
6.2
3.2
3.3
9.4
6.8
6.9
9.1
8.0
1.4
2.1
9.3
9.3
--
Temp.
ฐC
34.0
34.0
--
- -
39.5
34.0
31.0
29.0
29.0
32.5
36.3
46.0
43.0
35.6
6.1
6.3
32.2
31.0
40.0
39.0
34.0
41.0
36.2
4.3
4.8
so3,
ppm
--
--
-
175
175
--
BOD,
ppm
350
310
330
28
121
440
350
345
435
435
435
385
415
315
395
48
51
355
355
430
455
425
420
440
360
405
41
42
Bacteria/100 ml
Total
X 107
0.2
0.3
0.25
0.07
62
29
11
2
9
10
110
8
0.07
41
24
35
40
--
*"
Colif.
X 105
1
0.1
1
w
*"
0.02
15
23
290
60
360
300
0.2
1300
261
417
684
80
440
80
3400
180
2100
3700
740
1340
1520
1630
Colif.,
% of
total
5.0
0.3
"
0.001
1.4
12
32
6.0
3.2
38
0.29
32
14
16
17
a -- Not determined.
235
-------
Table II(continued). CHARACTERISTICS OF SECONDARY INFLUENT
Date
(1972)
Oct. 3
5
6
7
9
10
11
13
16
17
18
19
21
26
31
Time
1145
1045
0815
1342
0800
1245
1130
1515
0905
0825
0825
1430
1430
1230
1415
Monthly mean
S.D. from
monthly mean
S.D. from
project mean
Nov. 6
8
13
16
21
25
30
1025
1620
1330
1037
1215
1540
1015
Monthly mean
S.D. from
monthly mean
S.D. from
project mean
Project mean
S.D.
No. of analyses
PH
9.6
4.3
4.5
10.0
4.6
8.0
8.2
8.1
7.4
7.7
8.4
6.9
7.7
3.2
8.7
7.2
2.0
2.1
9.5
7.1
9.3
6.9
6.9
6.9
6.9
7.6
1.2
1.4
6.9
2.1
58
Temp.
ฐC
37.0
32.5
30.5
34.0
34.0
32.5
31.0
33.5
33.0
34.0
33.0
35.0
33.0
31.0
33.0
33.1
1.6
2.0
32.0
35.0
37.0
35.0
40.0
32.0
33.5
34.9
2.9
3.0
34.2
4.3
78
so3,
ppjn
__a
269
123
71
147
106
78
124
88
74
83
109
_.
154
78
116
54
60
60
138
89
235
197
108
322
164
93
96
142
72
30
BOD,
ppm
360
310
310
365
490
490
445
475
400
400
415
425
395
355
390
402
57
58
430
480
465
555
450
560
525
495
52
103
413
57
86
Bacteria/100 ml
Total
X 107
4
12
53
39
39
22
46
63
300
200
15
37
0.5
20
61
85
86
500
7
4
290
0.46
480
980
140
414
472
44
152
68
Colif.
X 105
3200
44
130
750
1200
120
200
290
2000
11000
4100
200
220
15
210
1580
2890
3010
110
190
42
22
3
5700
44
873
2130
2130
773
1630
86
Colif.,
% of
total
--
11
11
14
31
3.1
9.1
6.3
32
37
20
13
5.9
30
10
17
11
11
0.22
27
10
0.08
6.5
12
0.04
8.0
9.7
15
19
22
68
a -- Not determined.
236
-------
Table III. CHARACTERISTICS OF WASTES FROM MILL SECONDARY PONDS
AND SMALL SCALE TREATMENT UNITS
Exp. #
date
elap. time
1
10/6/72
Start
5:00 PM
1
10/7/73
0.9 Day
1
10/9/72
2.8 Days
Sample
point8
3
4
5
6
7
8
9
10
Mill sec.
3
7
8
9
10
Mill sec.
3
4
5
6
7
8
9
10
Mill sec.
PH
7.2
7.3
7.2
1.9
1.9
7.4
6.9
6.9
6.9
9.8
2.0
9.5
6.2
6.5
7.0
6.7
6.6
6.5
2.5
2.4
8.8
6.8
6.7
7.0
Temp.
ฐC
30.5
30.5
30.0
29.0
28.2
26.0
23.6
23.6
25.0
34.8
29.8
28.8
26.0
30.6
24.0
32.7
31.5
30.7
29.7
28.8
26.7
25.7
26.7
22.8
D.O.,
ppm
0.15
0.15
0.15
0.15
0.15
0.15
2.8
3.4
0.15
0.15
0.15
2.4
2.0
--
0.10
0.35
0.10
0.70
0.80
._
1.8
4.5
~
so3,
ppm
__b
__
__
--
__
3.4
3.4
3.4
--
--
3.1
2.9
2.9
--
__
._
--
--
_ _
2.4
2.2
1.3
Bacterij
Total
72 X 107
28 X lOJ*
26 X 10*
17 X 10?
14 X lOj
43 X 10
36 X 10ฐ
49 X 10ฐ
41 X lO*
53 X 107
--
54 X 10*
27 X 10ฐ
32 X 10ฐ
36 X 10
49 X 10ฐ
33 X 10ฎ
37 X 10*
32 X 10c
29 X 10c
70 X 10
28 X 107
40 X 10'
13 X 10S
a/100 ml
Coliforms
46 X 10*?
54 X 10ฐ
70 X 10
-CIO
^.10
^10 A
13 X 10JJ
13 X ID*?
11 X 10ฐ
75 X 10ฐ
70 4
60 X 10^
80 X 10^
110 X 10"!
>100 X 10^
7 100 X 106
^ 100 X 106
~ 100 X 10?
/I
62 X 10^
29 X ICT
50 X 10ฃ
23 X 10^
52 X 10
Colif.,
% of
total
6.4
1.9
2.7
ฃ. 0.6
--0.7
-CO. 2
0.36
0.27
0.27
14
--
1.3
0.02
0.25
0.31
7 2.0
-3.0
; 2.5
; 0.3
21
4.1
0.18
5.8
4.0
CO
aSee Figures 12 and 13,
-- Not determined.
-------
Table Ill(contlnued). CHARACTERISTICS OF WASTES FROM MILL SECONDARY PONDS
AND SMALL SCALE TREATMENT UNITS _
Exp. #
date
elap. time
1
10/10/72
4.0 Days
1
10/11/72
4.8 Days
1
10/13/72
7.0 Days
Sample
point3
3
7
8
9
10
Mill sec.
3
7
8
9
10
Mill sec.
3
4
5
6
7
8
9
10
Mill sec.
PH
7.2
1.6
6.5
6.6
6.5
7.2
7.0
1.8
7.5
6.6
6.5
7.0
6.3
6.3
6.3
1.7
1.7
6.9
6.6
6.4
6.9
Temp.
ฐC
__b
ป v
_
21.7
22.7
22.0
27.0
21.9
21.0
22.0
21.0
21.1
29.4
28.9
28.8
28.3
27.7
26.8
21.8
23.8
22.7
D.O.,
PPป
ซ,_
__
4.4
0.4
...
0.20
__
__
4.5
5.3
--
0.10
0.45
0.10
0.70
0.80
-.
2.2
2.8
S03,
ppm
>
mซ
2.9
2.9
3.1
74
*ป~
60
2.8
2.6
3.0
--
_-
. *M
--
--
44
3.3
3.4
3.0
Bacteria/100 ml
Total
15 X 108
*
30 X 103
20 X 10ฐ
22 X 10ฎ
36 X 10ฎ
17 X 10^
w M
50 X 103
28 X 108
18 X 10*|
31 X 10?
15 X 10ฐ
17 X 10ฐ
21 X 10ฐ
34 X 10*
6 X 10]?
22 X 10ฃ
50 X 10ฎ
20 X 108
35 X 108
Coliforms
24 X 107
M.
22 X 102
12 X 10J
68 X 10ฐ
52 X 10.
26 X 10"
__
60 X ID2
70 x 10;
60 X 106
26 X 10ฐ
10 X 10^
42 X 10
10 x 10;
21 X 103
420
20 X 10J?
63 X 10
12 X 106
29 X 10ฐ
Colif.,
% of
total
16
.
7.3
0.006
3.0
1.5
0.15
12
0.002
3.3
0.84
6.7
2.5
4.8
6.2
0.007
9.1
0.013
0.60
0.83
ro
w
oo
aSee Figures 12 and 13.
-- Not determined.
-------
Table III(continued). CHARACTERISTICS OF WASTES FROM MILL SECONDARY PONDS
AND SMALL SCALE TREATMENT UNITS
Exp. #
date
elap. time
1
10/16/72
10.0 Days
1
10/19/72
12.9 Days
Sample
point a
3
4 Top
4 Bottom
5 Top
5 Bottom
6
7
8
9
10
Mill sec.
3
4 Top
4 Bottom
5 Top
5 Bottom
6
7
8
9
10
Mill sec.
pH
8.7
8,5
__
8.1
--
1.6
1.6
7.5
6.6
6.6
6.9
6.5
6.4
__
6.4
--
1.8
1.7
7.6
6.6
6.7
7.0
Temp.
ฐC
31.9
31.4
__
30.8
--
30.0
29.3
28.0
22.6
21.7
23.4
31.0
27.7
..
26.8
-_
25.8
24.0
24.4
22.0
20.4
22.0
D.O.,
ppm
0.20
0.45
.-
0.20
0.60
0.70
2.6
2.7
0.05
0.05
__
0.10
--
1.0
1.2
0.1
2.2
2.4
S03,
ppm
72
--b
__
--
--
--
..
30
3.2
3,6
3.9
75
--
__
--
--
--
-_
51
2.5
3.0
2.8
Bacteria/100 ml
Total
37 X 10J
36 X 10*
117 x 10*
29 X 10ฐ
73 X 10*
19 X 10?
35 X 10
39 X 10ฐ
130 X 10^
73 X 10ฐ
24 X 10ฐ
40 X 10ฐ
33 X 10ฐ
64 X 10*
29 X 10ฐ
44 X 10;:
26 X 103
35 X 102
39 X 102
88 X 10**
59 X 10ฎ
21 X 10B
Coliforms
12 X 10ฎ
11 X 10ฎ
60 X 10*
9 X 10^
14 x 10;:
18 X 103
600 .
36 X 10^
19 X 10^
17 X 10?
77 X 10
14 X 107
11 X 107
56 X 10^
12 X 10^
62 X 10B
580
200
30 4
34 X 10^
8 X 10^
44 X 106
Colif.,
7. of
total
32
31
51
3.1
19
0.95
0.17
0.92
1.50
0.23
3.2
3.5
3.3
8.8
4.1
14
2.2
5.7
0.8
0.004
0.14
2.1
NJ
U>
vฃ>
aSee Figures 12 and 13.
b Not determined.
-------
Table Ill(contlnued). CHARACTERISTICS OF WASTES FROM MILL SECONDARY PONDS
AND SMALL SCALE TREATMENT UNITS
Exp. #
date
elap. time
1
10/24/72
17.9 Days
1
10/26/72
19.8 Days
Sample
point a
3
4
5
6
7
8
9
10
Mill sec.
3
4
5
6
7
8
9
10
Mill sec.
t>H
6.6
7.0
7.2
1.8
2.0
8.9
7.2
6.8
7.0
8.6
6.4
5.0
1.5
1.5
3.1
7.3
7.4
7.0
Temp.
ฐC
29.4
28.7
27.9
26.9
26.0
25.3
21.8
22.4
19.4
31.8
29.0
27.4
25.7
23.7
23.4
21.8
21.7
21.5
D.O.,
pom
0.05
0.05
0.20
1.4
1.6
m m
5.4
0.5
--
1.5
2.8
3.1
4.3
4.1
--
8.4
2.1
--
so3,
ppm
83
b
_.
__
--
76
2.4
2.9
3.6
138
--
._
._
83
2.4
2.2
3.3
Bacteria/100 ml
Total
29 X loj
23 x 10;
60 X 1C7
88 X 104
37 X 105
98 X 10;
17 X 10?
14 X 108
32 X 108
50 X 10ฐ
43 X 106
56 X 10ฐ
35 X 102
62 X 104
20 X 10J
94 X 108
52 X 108
60 X 108
Coli forms
60 X lOJ?
70 X 10ฐ
80 X 10ฐ
20 X lO;
21 X 104
60 ,
31 X 10J
16 X 10ฐ
24 X 10ฐ
6 X 10ฐ
10 X 10ฐ
10 X 10ฐ
-110
. --:- 10
<ฃ, 10
24 x 10;?
14 X 10ฐ
37 X 10ฐ
Colif.,
% of
total
21
30
13
2.3
5.7
0.61
0.002
1.1
0.75
12
23
18
<- 0.30
^ 0.002
^0.05
0.0003
0.27
0.62
10
.p-
o
aSee Figures 12 and 13.
b -- Not determined.
-------
Table m(continued). CHARACTERISTICS OF WASTES FROM MILL SECONDARY PONDS
AND SMALL SCALE TREATMENT UNITS
Exp. #
date
elap. time
1
10/27/72
20.9 Days
1
10/30/72
23.9 Days
1
10/31/72
24.9 Days
Sample
point a
3
4
5
7
9
10
3
4
5
7
9
10
3
4 Top
4 Bottom
5 Top
5 Bottom
6
7
8
9
10
Mill sec.
PH
6.4
6.3
6.2
1.4
7.1
7.0
8.2
8.4
8.5
1.9
7.0
6.8
8.1
7.8
*-.
7.5
1.7
1.5
7.4
6.8
6.5
7.0
Temp.
ฐC
32.0
32.0
31.1
30.0
21.6
21.6
28.8
28.2
27.4
26.0
22.0
22.2
27.4
26.8
_
26.8
24.9
23.8
23.6
22.4
21.8
18.2
D.O.,
ppm
0.30
0.15
0.05
1.6
2.0
2.6
0.40
0.15
0.10
2.2
2.7
2.3
0.30
0.20
__
0.05
0.80
1.5
_.
3.2
1.6
so3,
ppm
..b
_-
--
--
--
--
--
--
--
--
51
--
__
_ ซ.
_.
--
88
2.3
3.0
3.4
Bacterj
Total
..
__
..
--
--
--
--
--
--
72 X 10'
10 X 108
40 X 10*
11 X 10ฐ
40 X 10,
24 X 10*
40 X 10*
49 X 10
82 X 10ฐ
10 X 10*
64 X 108
La/100 ml
Coliforms
..
__
--
--
--
m
--
--
--
..
.-
--_
11 X 10
15 X 107
33 X 108
16 X 107
24 X 108
9.0 X 10;
3.3 X 10^
18 X 10^
29 X 10?
13 X 10
23 X 106
Colif.,
% of
total
-_
--
--
--
--
--
-_
--
--
--
15
15
8.3
14
6.0
0.38
8.3
3.7
0.00004
0.13
0.36
aSee Figures 12 and 13.
b -- Not determined.
-------
Table IH(continued) . CHARACTERISTICS OF WASTES FROM MILL SECONDARY PONDS
AND SMALL SCALE TREATMENT UNITS
1?vซt Jt
I&XP * TT
Jr
date
1
11/2/72
26.9 Days
1
11/3/72
28.3 Days
1
11/6/72
30.8 Days
Sample
point8
3
4
5
7
9
10
3
4
5
7
9
10
3
4 Top
f
4 Bottom
5 Top
5 Bottom
6
7
8
9
10
Mill sec.
PH
6.4
6.3
6.3
1.4
6.7
6.6
7.7
7.4
7.5
1.6
6.7
6.6
9.9
9.5
9.3
1.2
1.2
8.6
6.6
6.6
6.8
Temp.
26.8
26.0
25.7
24.2
20.1
20.4
26.0
25.4
24.6
23.3
20.6
20.1
27.2
24.8
* **
23.0
M ป
21.0
19.8
18.8
19.6
20.5
20.0
D.O.,
ppm
0.30
0.20
0.05
1.6
1.8
2.4
0.35
0.15
0.05
1.8
1.6
2.3
0.85
0.25
*ป
0.10
1.5
2.0
0.5
2.8
so3,
ppm
--
--
ป-
--
* ป
ซ *
-ป
--
56
m
49
2.5
2.6
4.3
Bacteria/100 ml
Total
__
--
--
"-
~~
--
--
-
--
~
29 X 10"
23 X 10JJ
27 X 10^
66 X 107
38 X 10-J
46 X 10;
43 X 10*
79 X 10;
62 X 108
87 X 108
32 X 108
Conforms
--
~
~~
m
^ ""
-"
~ ~
""*
ซ ซ
~"~-J
20 x 10;
26 X 107
32 X 10ฐ
14 X 10'
17 X 10,
2.1 X 10Z
Z.IO
7 X 102
14 X ID*
12 X 10ฐ
21 X 10b
Colif.,
% of
total
--
~
^
""
_
*
"*
v M
^ *
*" **
6.9
11
12
21
4.5
4.6
0*.89
0.00002
0.14
0.66
CO
aSee Figures 12 and 13.
Not determined.
-------
Table IH(continued) . CHARACTERISTICS OF WASTES FROM MILL SECONDARY PONDS
AND SMALL SCALE TREATMENT UNITS
Exp. #
date
elap. time
1
11/8/72
33.0 Days
End
2
11/8/72
Start
5:00 PM
2
11/10/72
1.9 Days
2
11/13/72
4.8 Days
Sample
point3
3
4 Top
4 Bottom
5 Top
5 Bottom
6
7
8
9
10
Mill sec.
3
4
5
9
10
3
4 Top
4 Bottom
5 Top
5 Bottom
9
10
Mill sec.
PH
6.1
6.4
._
7.3
_
1.5
1.4
9.6
6.8
6.5
6.8
7.4
7.6
7.7
6.8
7.2
8.3
9.1
__
9.3
--
6.6
7.8
6.9
Temp.
ฐC
28.8
27.7
-.
27.0
__
26.1
25.0
24.2
19.8
19.8
20.4
23.7
22.4
22.2
19. ,9
20.6
30.4
29.6
_.
29.4
--
21.8
22.6
21.2
D.O.,
ppm
0.40
0.25
..
0.10
._
1.4
1.6
__
8.3
4.4
0.60
0.40
0.25
2.2
7.9
0.35
0.20
__
0.10
-_
1.2
8.0
** **
so3,
ppm
106
--b
_-
.-
__
--
--
83
2.3
2.5
3.7
--
--
--
83
--
_-
--
--
4.4
3.0
4.1
Bacteria/100 ml
Total
13 X IO7
54 X 10ฐ
55 X 10y
59 X I0j
29 X IO9
63 X IO2
34 X 10*
69 X 10*
11 X 10ฎ
15 X 10ฐ
24 X 10ฎ
--
"""ป
88 X 10'
62 X IO7
11 X IO9
11 X 10ฐ
17 X IO9
24 X IO9
11 X IO9
88 X 10
Co li forms
64 X IO6
12 X 10ฐ
13 X IO9
10 X IO7
10 X IO9
^-10
69 X 10
60 X 10*
13 X 10^
62 X IO6
--
--
--
"""?
15 X 10y
48 X 10^
10 X 10ฐ
56 X 10^
17 X 10ฐ
23 X 10b
94 X 105
20 X 10
Colif .,
% of
total
49
22
24
1.7
34
< 0.16
<- 0.003
1.0
0.0005
0.09
2.6
--
--
..
--
--
17
7.7
9.1
5.1
10
0.10
0.09
0.23
10
-p-
aSee Figures 12 and 13,
b -- Not determined.
-------
Table Ill(continued). CHARACTERISTICS OF WASTES FROM MILL SECONDARY PONDS
AND SMALL SCALE TREATMENT UNITS
Exp. #
date
elap. time
2
11/14/72
5.9 Days
2
11/15/72
6.9 Days
2
11/16/72
7.7 Days
2
11/18/72
9.8 Days
2
11/20/72
11.9 Days
Sample
point8
3
4
5
9
10
3
4
5
9
10
3
4 Top
4 Bottom
5 Top
5 Bottom
9
10
Mill sec.
3
4
5
9
10
3
4
5
9
10
PH
7.5
7.7
8.1
6.5
7.3
7.0
8.5
9.0
6.6
7.4
6.1
6.1
__
6.1
6.2
7.2
7.1
6.2
6.2
6.3
6.4
7.5
6.5
6.7
6.7
7.4
Temp.
ฐC
30.0
29.4
28.7
21.4
21.6
22.7
20.6
19.8
22.4
23.0
27.2
25.0
..
20.0
22.4
24.0
20.8
25.1
24.7
24.7
22.4
23.7
26.2
25.3
25.0
23.6
D.O.,
ppm
0.20
0.35
0.10
2.4
8.1
2.5
3.0
2.9
2.2
8.5
0.30
1.2
__
1.2
1.2
7.4
--
1.0
0.70
0.40
1.7
8.4
0.70
0.40
0.05
so3,
ppm
__b
-.
m m
--
--
--
..
-.
-------
Table Ill(continued). CHARACTERISTICS OF WASTES FROM MILL SECONDARY PONDS
AND SMALL SCALE TREATMENT UNITS
Exp. #
date
elap. time
2
11/21/72
12.8 Days
Finish
3
11/21/72
Start
1:00 PM
3
11/25/72
4.0 Days
3
11/30/72
8.8 Days
Sample
point a
3
4 Top
4 Bottom
5 Top
5 Bottom
10
Mill sec.
3
4 Top
4 Bottom
5 Top
5 Bottom
10
Pond 1
Pond 2
3
4 Top
4 Bottom
5 Top
5 Bottom
10
Mill sec.
PH
6.4
6.4
--
6.3
__
7.2
7.0
6.0
6.0
6.0
6.9
7.3
7.0
6.3
6.2
--
6.2
--
6.4
7.0
Temp.
ฐC
37.0
35.4
--
33.0
__
23.8
21.2
27.0
23.4
26.2
23.9
25.0
18.4
24.5
23.0
23.0
_.
20.0
19.8
D.O.,
ppm
3.4
2.8
2.0
._
7.7
0.70
1.8
1.6
8.2
--
0.20
0.50
--
0.40
8.2
~
903,
ppm
169
--b
--
--
_.
2.8
3.0
85
__
--
4.5
64
4.7
268
--
--
--
2.9
7.9
Bacteria/ 100 ml
Total
46 X 106
33 X 106
43 X 108.
90 X 10ฐ
94 X 10B
16 X 10-J
20 X 108
86 X 107
54 X 109
49 X 108
69 X 108
12 X 10g
28 X 10?
48 X 10ฐ
43 X 10^
36 X 10
65 X 107
11 X 109
10 x 10;
15 X 10ฐ
29 X 10^
97 X 108
Col i forms
27 X lOjj
10 X 10^
22 X 107
63 X 10^
15 X 10^
40 X 10^
80 X 105
17 X 107
60 X 108
54 X 107
64 X 107
47 X 107
23 X 10^
73 X 10^
18 X 10'
90 X 10ฐ
60 X 10^
53 X 10S
31 X 10
39 X 107
36 X 10^
92 X 106
Colif.,
% of
total
59
30
5.1
70
16
0.003
0.40
20
11
11
9.3
3.9
0.0008
17
3.8
25
9.2
48
3.1
26
0.12
0.95
Ni
-fS
Ul
aSee Figures 12 and IJ,
-- Not determined.
-------
Tซblซ IV. CHA8ACTBRISTICS OF EFFUIKMTS FBOM PONDS 1 AND 2
PUMMG PARALLEL OPERATION
Date
(1972)
Feb. 1
2
3
a
10
11
12
S.D. (Interval)
S.D. (Pro1.)
March 13
14
15
22
S.D. (Interval)
S.D. (Pro1.)
June 28
S.D. (Interval)
S.D. (Pro1.)
July 5
(0100) 6
(1445) 6
7
(0800) 8
(1540) 8
(2100) 8
DH
PI
6.7
6.6
6.7
6.7
6.9
6.6
6.7
6.7
0.1
0.1
6.8
6.8
7.1
7.0
6.9
0.2
0.3
7.0
--
--
5.4
5.7
5.3
5.8
6.5
6.6
6.7
P2
6.8
6.8
6.8
6.8
6.8
6.6
6.7
6.8
0.1
0.1
6.8
6.8
7.0
6T9
6.9
0.1
0.2
6.7
--
--
5.7
5.5
5.4
6.1
6.5
6.6
6.6
Tซm>
PI
14.0
13.0
14.0
17.5
18.0
18.4
18.6
16.2
2.4
1 97F
21.5
19.7
21.0
20.5
20.7
0.8
4.3
28.0
--
--
28.5
28.0
27.8
26.5
25.5
25.1
24.5
.. Cj_
P2
15.0
15.0
15.0
18.1
18.0
19.3
19.3
17.1
2.0
9.9
20.8
20.8
21.9
22.0
21.4
0.7
5.5
29.5
--
--
29.5
29.5
28.0
29.0
28.7
28.0
28.6
SO,"
PI
..ซ
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
. _
--
--
--
--
--
, ppป
ฅ2
--
--
--
--
_.
--
--
--
..
.-
..
--
ป_
--
. .
--
--
--
--
BOD
PI
166
166
183
175
136
181
181
170
16
182
121
124
124
92
115
16
132
75
--
--
__
94
94
81
81
81
81
PPซ
P2
161
161
201
148
157
172
172
167
17
180
102
118
118
90
107
14
122
98
__
93
93
97
97
97
97
Bacteria/100 ml
Total
X 10?
PI
260
110
40
92
390
180
400
210
144
29ฐ
95
117
220
39
118
76
394
1300
--
630
720
560
430
--
--
*> V
P2
110
150
28
190
330
20
290
160
120
244
52
79
230
72
108
82
298
700
--
--
75
300
360
280
--
--
ป *
Coll forma
X 105
PI
290
120
33
130
15
150
240
140
100
116
130
240
160
410
235
126
135
270
190
20
80
25
36
29
26
P2
250
120
8
90
2
20
60
79
87
137
190
130
140
350
202
102
106
500
--
-.
21
7
20
6
12
15
17
Colifonu,
% of total
PI
1.1
1.1
0.82
1.4
0.04
0.83
0.60
0.84
0.44
0.58
1.4
2.1
0.73
11
3.8
4.8
5.7
0.21
--
0.30
0.03
0.14
0.06
--
**
P2
2.3
0.80
0.29
0.47
0.01
1.0
0.21
0.73
0.77
0.83
3.7
1.6
0.61
4.9
2.7
2.0
2.8
0.71
--
..
0.28
0.02
0.06
0.02
--
--
a -- Not determined.
-------
Table IV (continued).
CHARACTERISTICS OF EFFLUENTS FROM PONDS 1 AND
DURING PARALLEL OPERATION
Date
(1972)
July 11
18
19
21
25
27
31
Mean
S.D. (Interval}
S.D. (Proj.)
Aug. 3
6
11
16
18
24
29
30
31
Mean
S.D, (Interval)
S.D. (Proj.)
Nov. 13
S.D. (Interval)
S.D. (Proj.)
Proj. Mean
S.D.
No. of Analyses
PH
PI
5.6
7.0
6.6
6.9
7.2
6.7
6.3
0.6
0.8
6.7
6.6
6.6
7.2
6.9
7.4
7.3
7.1
7.2
7.0
0.3
0.4
7.0
--
6.7
0.5
35
P2
5.8
6.8
6.6
6.9
7.2
6.8
5.9
0.7
0.7
6.8
6.7
6.8
7.1
6.9
7.4
7.3
7.1
7.4
7.1
0.3
0.5
6.6
--
--
6.7
0.5
35
Temp., ฐC.
Pi
26.0
30.0
29,0
30.4
26.0
28.9
27.4
1.9
3.8
28.7
31.9
27.0
25.8
23.9
26.6
29.8
28.8
27.6
27.8
2.3
4.4
21.9
--
24.3
5.2
35
P2
28.6
32.0
31.4
32.8
29.4
30.8
29.7
1.6
4.1
29.9
33.0
29.8
28.4
27.0
29.6
31.7
31.0
29.8
30.0
1.8
4.5
21.3
--
--
26.1
35
SO,*, ppm
?r
___ 8
4.0
2.4
3.2
1.1
1.3
4.4
3.4
4.1
3.7
3.9
0.4
0.6
3.3
--
..
3.6
0.7
7
P2
4.6
3.6
4.1
0.7
0.8
4.6
3.1
4.3
4.1
4.0
0.7
0.7
3.3
--
_-
3.9
0.6
7
BOD, ppm
Pi
74
61
61
101
112
76
82
90
16
86
78
94
87
89
103
72
94
94
89
89
9
93
214
--
..
109
116
35
P2
93
87
87
111
99
74
65
92
12
94
90
81
74
69
71
56
93
93
100
81
14
85
126
--
-_
107
112
35
Bacteria/100 ml
Total
X 107
PI
-,
585
122
195
210
520
800
500
450
496
210
216
1900
--
..
453
443
22
P2
--
254
124
171
230
560
590
1200
580
632
351
468
1400
--
._
356
365
22
Coll forms
X 105
Pi
250
140
50
2
3
550
870
162
229
254
530
4
6
4
4
930
270
220
180
239
314
317
390
-.
.-
194
232
36
P2
14
5
6
3
11
130
310
41
84
266
600
24
8
2
5
1400
720
740
320
424
483
550
80
..
-.
176
326
36
Col i forms,
% of total
PI
--
0.13
0.12
1.2
2.5
0,01
0.34
0.44
0.40
0.74
1.00
1.1
0.21
__
1.2
2,3
22
P2
--
0.10
0.12
1.1
2.6
0.01
1.2
0.62
0.56
1,0
1.00
0.98
0,06
__
__
1.0
1.3
22
-- Not determined.
-------
Table V. EFFECT OF MILL CHLORINATION ON BACTERIAL MOTILITY
AND ON COLIFORM CONCENTRATIONS
Date
(1972)
May 17
May 18
May 19
Cl added
Kg/day (#/day)
0
182 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
363 ( 800)
408 ( 900)
454 (1000)
0
91 ( 200)
136 ( 300)
182 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
363 ( 800)
408 ( 900)
454 flOOO)
0
91 ( 200)
136 ( 300)
182 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
363 ( 800)
408 ( 900)
454 (1000)
ppm
0
8.1
9.9
12.0
14.0
16.7
19.1
21.2
0
4.1
6.2
8.2
10.5
12.8
14.9
17.0
19.2
21.2
0
4.0
6.0
7.8
9.6
11.0
12.9
14.8
17.0
19.2
Eff.
pH
6.7
6.4
6.3
6.3
6.3
6.3
6.2
6.2
6.6
6.5
6.5
6.5
6.4
6.3
6.2
6.2
6.1
6.1
7.4
7.3
7.2
7.2
7.2
7.1
7.1
7.0
'7.0
6.9
Motile
spirilla
per field
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
0
0.01-0.1
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
0.1-1
Colif .7100 ml
X 105
_.*
--
._
__-
-_
._
_.
-.-
710
540
640
700
640
680
770
610
930
730
M
.
_
ปซ
Colif.
redn.,
%
--
_-
__
_ _
_ซ
__
..
0
25
10
3
10
5
0
18
0
0
^ ^
.
^^
w
*
^
ป V
a Not determined.
248
-------
Table V (continued). EFFECT OF MILL CHLORINATION ON BACTERIAL
MOTILITY AND ON COLIFORM CONCENTRATIONS
Date
(1972)
May 25
May 26
Cl added
Kg/dav (#/day)
0
45 ( 100)
68 ( 150)
91 ( 200)
113 ( 250)
136 ( 300)
182 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
454 (1000)
0
91 ( 200)
136 ( 300)
182 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
363 ( 800)
408 ( 900)
454 (1000)
PPM
0
2.2
3.2
4.2
5.2
6.2
8.2
10.2
12.5
14.5
20.4
0
4.1
6.2
8.3
10.6
13.1
15.8
18.2
20.6
23.5
Eff.
PH
6.9
6.9
6.8
6.8
6.8
6.7
6.7
6.6
6.6
6.5
6.3
6.8
6.7
6.7
6.6
6.6
6.5
6.4
6.4
6.3
6.2
Motile
spirilla
per field
1-10
0.1-1
0.1-1
0.1-1
1-10
1-10
1-10
0.1-1
1-10
0.1-1
0
0
1-10
1-10
1-10
1-10
1-10
1-10
1-10
1-10
0.1-1
Colif ./100 ml
X 105
550
VI
/I
>'l
>'l
>1
~.rl
x'l
xl
-?\
~sl
--
Colif.
redn. ,
7.
0
_ P
" *
"
"*
*
" "
^ ^
^ *
^ ^
^ ^
""
""
* -- Not determined.
249
-------
Table VI. EFFECT OF CAUSTIC ADDITION ON ACTIVITY OF CHLORINE IN MILL SYSTEM
Date
(1972)
May 25
Additions to effluent
NaOH
Kg/day (#/day)
0
0
0
0
0
0
0
0
0
0
0
131 (288)
131 (288)
131 (288)
131 (288)
131 (288)
131 (288)
131 (288)
131 (288)
131 (288)
131 (288)
Chlorine
Kg/day (#/day)
0
45 ( 100)
68 ( 150)
91 ( 200)
113 ( 250)
136 ( 300)
182 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
454 (1000)
0
45 ( 100)
68 ( 150)
91 ( 200)
113 ( 250)
136 ( 300)
182 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
ppm
0
2.2
3.2
4.2
5.2
6.2
8.2
10.2
12.5
14.5
20.4
0
2.1
3.2
4.5
5.7
6.8
9.1
11.1
13.0
15.2
Eff.
PH
__ซ
.-
__
_ซ
__
__
m
--
__
._
--
--
ป
--
--
--
__
--
--
** **
Cl reaid.,
ppm @
5 Min
0
0
0
0
0
0.69
0.69
1.1
1.4
1.4
2.7
0
0
0
0.78
1.4
1.6
3.1
5.9
6.5
5.6
2 Hr
0
0
0
0
0
0
0
0
0
0
0.86
0
0
0
0
0
0
0.9
1.0
2.4
2.4
Motile
sp. /field
@ 2 hrs
1-10
0.1-1
0.1-1
0.1-1
1-10
1-10
1-10
0.1-1
1-10
0.1-1
0
1-10
0.1-1
0.1-1
0
0
0
0
0
0
0
Colif./lOO ml
@ 2 hrs.
X 105
550
> 1
>1
y 1
>1
;-i
>i
,>i
>i
>i
>i
550
>1
> 1
0.034
0.001
0.001
<ฃ 0.001
<ฃ. 0.001
^ 0.001
--...0.001
Colif .
redn. ,
%
. 99.818
-.'. 99.818
..99.818
^99.818
-99.818
-L99.818
99.818
.'-99.818
,-99.818
<99.818
--
^ 99.818
99.999
799.999
~99.999
to
Ol
o
-- Not determined.
-------
Table VI (continued). EFFECT OF CAUSTIC ADDITION ON ACTIVITY OF CHLORINE IN MILL SYSTEM
Date
(1972)
May 26
Additions to effluent
NaOH j
Kg /day (#/day)
0
0
0
0
0
0
0
0
0
0
0
98 (216)
98 (216)
82 (180)
98 (216)
114 (252)
114 (252)
147 (324)
65 (144)
65 (144)
Chlorine
Kg/day (#/day)
0
91 ( 200)
136 ( 300)
182 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
363 ( 800)
408 ( 900)
454 (1000)
0
91 ( 200)
136 ( 300)
182 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
363 ( 800)
408 ( 900)
454 (1000)
ppm
0
4.1
6.2
8.3
10.6
13.1
15.8
18.2
20.6
23.5
0
4.8
7.0
9.5
12.1
14.6
16.7
19.0
21.3
23.5
Eff
pH
6.8
6.7
6.7
6.6
6.6
6.5
6.4
6.4
6.3
6.2
6.9
6.9
6.8
6.7
6.8
6.7
6.7
6.5
6.5
6.4
Cl resid,
ppm (?
5 Min
0
0
0
0
0.43
0.69
0.95
1.70
2.00
2.60
0
0
1.70
2.50
5.30
5.80
4.50
3.00
3.10
2 Hr
0
0
0
0
0
0
0
0
0
0.86
0
0
0
0
2.00
2.00
1.60
0
0
~
Motile
ap/field
@ 2 hrs
1-10
1-10
1-10
1-10
1-10
1-10
1-10
1-10
0.1-1
0.1-1
1-10
0.1-1
0
0
0
0
0
0.01-0.1
0
0
Colif/100 ml
@ 2 hrs
X 105
_^F
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
__
--
Colif
redn,
%
--
--
-.
--
--
--
--
--
-_
_.
--
--
--
--
--
--
--
--
N)
U1
a -- Not determined.
-------
Table VI (continued). EFFECT OF CAUSTIC ADDITION ON ACTIVITY OF CHLORINE IN MILL SYSTEM
Date
(1972)
May 26
Additi
NaOH
Kg/day (#/dav)
0
164 ( 360)
164 ( 360)
228 ( 504)
98 ( 216)
163 ( 360)
131 ( 288)
163 ( 360)
228 ( 504)
129 ( 285)
0
490 (1080)
458 (1010)
327 ( 720)
458 (1010)
392 ( 864)
458 (1010)
458 (1010)
458 (1010)
458 (1010)
458 (1010)
0
pns to effluent
Chlorine
Kg/day (#/day)
0
91 ( 200)
136 ( 300)
182 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
363 ( 800)
408 ( 900)
454 (1000)
0
0
91 ( 200)
136 ( 300)
182 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
363 ( 800)
408 ( 900)
454 (1000)
454 (1000)
ppm
0
4.7
7.0
9.2
11.1
12.9
14.8
16.6
18.5
20.2
0
0
3.6
5.5
7.3
9.3
10.8
12.8
14.3
16.1
17.7
17.6
Eff
pH
7.2
7.1
7.0
6.9
6.8
6.8
6.8
6.7
6.5
6.5
6.9
7.7
7.5
7.4
7.4
7.2
7.2
7.1
7.0
6.9
6.8
6.4
Cl resid,
ppm @
5 Min
0
0
1.40
--
5.10
6.60
6.20
4.30
4.10
3.20
0
0
0
0
1.7
2.6
3.1
4.3
6.0
4.7
6.1
1.9
2 Hr
0
0
0
0
0.69
2.00
2.80
0.95
2.00
2.60
--
--
__
--
--
__
--
--
--
"
Motile
sp/field
@ 2 hrs
1-10
0.01-1
0
0
0
0
0
0
0.01-0.1
0
--
--
--
--
--
--
--
--
--
--
--
Colif/100 ml
@ 2 hrs
X 105
r>
--
--
--
--
--
--
__
--
--
--
--
--
--
--
--
--
--
--
"
Colif
redn,
%
ป
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
--
._
--
--
._
"
Ul
K)
8 -- Not determined.
-------
Table VI (continued). EFFECT OF CAUSTIC ADDITION ON ACTIVITY OF CHLORINE IN MILL SYSTEM
Date
(1972)
June
29
July
20
July
21
Additions to effluent
NaOH
Kg/day (#/day)
0
11 (^ 24)
11 (^24)
" ( 24)
11 ( 24)
19 ( 42)
24 ( 54)
47 ( 103)
0
0
0
0
98 ( 216)
98 ( 216)
98 ( 216)
98 ( 216)
131 ( 288)
0
0
0
0
0
0
0
0
98 ( 216)
Chlorine
Ka/day (#/day)
0
91 ( 200)
91 ( 200)
91 ( 200)
91 ( 200)
91 ( 200)
91 ( 200)
91 ( 200)
0
91 ( 200)
136 ( 300)
181 ( 400)
91 ( 200)
113 ( 250)
136 ( 300)
159 ( 350)
159 ( 350)
0
181 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
363 ( 800)
408 ( 900)
454 (1000)
113 ( 250)
ppm
0
5.0
4.8
4.6
4.2
3.9
4.0
4.4
0
4.1
6.5
9.1
3.9
4.8
5.6
6.2
6.2
0
7.5
9.3
11.1
12.7
14.3
16.4
17.5
5.0
Eff
PH
7.2
--
--
--
--
--
--
--
6.4
--
--
--
--
--
--
--
--
6.6
6.2
6.2
6.1
6.0
5.9
5.8
5.8
6.6
Cl resid,
ppm (3
5 Min
0
0.43
0.86
1.00
1.40
1.50
1.50
1.30
0
0
0.69
1.70
1.50
2.60
2.70
2.30
2.80
0
0.43
1.30
1.50
2.20
2.60
3.20
3.90
1.21
2 Hr
0
0
0
0
0
0
0
0
0
0
0
0.69
0
0
0
0
1.21
0
0
0.86
1.30
1.70
1.70
1.70
2.20
0.52
Motile
sp/field
@ 2 hrs
1-10
0.01-0.1
0.01-0.1
0.01-0.1
0
0
0
0
1-10
1-10
1-10
1-10
0.01-0.1
0.01-0.1
0
0.01-0.1
0
1-10
1-10
1-10
1-10
0.1-1
0.1-1
0.01-0.1
0.01-0.1
0
Colif/100 ml
@ 2 hrs
X 10s
310
29
2.2
0.0024
0.0018
0.0002
0.0001
0.0014
26
15
10
26
0.001
0.002
0.001
0.002
0.003
21
21
22
20
2.2
0.3
0.035
0.01
0.001
Colif
redn,
%
90.645
99.290
>99.999
^99.999
>99.999
>99.999
^99.999
__
42.308
61.538
0
99.996
99.992
99.996
99.992
99.988
-. ป
0
0
4.762
89.524
98.571
99.833
99.952
99.995
a -- Not determined.
-------
Table VII. EFFECT OF AMMONIA ADDITION ON CHLORINE ACTIVITY IN MILL SYSTEM
Date
(1972)
May 16
Chlorine
addition
Kg/day (#/day)
0
227 ( 500)
250 ( 550)
272 ( 600)
295 ( 650)
318 ( 700)
363 ( 800)
408 ( 900)
454 (1000)
0
0
113 ( 250)
136 ( 300)
182 ( 400)
182 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
363 ( 800)
408 ( 900)
454 (1000)
ppm
0
10.4
11.4
12.5
13.8
15.2
17.6
20.0
22.4
--
ป m
5.7
6.8
8.9
8.0
10.0
11.7
13.7
15.4
17.3
19.6
Ammonia addition
Kg/day (#/day)
0
0
0
0
0
0
0
0
0
0
21 ( 47)
21 ( 47)
21 ( 47)
21 ( 47)
65 (144)
65 (144)
65 (144)
65 (144)
65 (144)
65 (144)
65 (144)
% of
reoa
0
0
0
0
0
0
0
0
0
--
--
78
65
49
148
118
99
85
74
66
59
Eff
PH
6.8
6.6
6.6
6.6
6.6
6.5
6.4
6.4
6.4
6.7
6.8
6.8
6.6
6.6
6.8
6.8
6.6
6.6
6.5
6.4
6.4
Chlorine
resid, ppm
5 Min
0
0
0
0.86
0.43
0.86
1.30
1.40
1.90
0
0
0
0.43
0.86
1.00
1.00
1.40
1.40
2.00
2.40
2.40
Hr
0
0
0
0
0
0
0
0.43
0.95
0
0
0
0
0
0
0
0.86
0.86
0.86
1.30
M
Motile
sp/field
@ 2 hr
__b
--
--
--
--
--
--
--
--
-_
--
--
--
--
--
--
**
*Percent of the NH^4" required to neutralise the HCl produced from the hydrolysis of Cl?
b -- Not determined.
-------
Table Vll(continued), EFFECT OF AMMONIA ADDITION ON CHLORINE ACTIVITY IN MILL SYSTEM
Date
(1972)
May 17
Chlorine
addition
Kg/day (#/day)
0
182 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
363 ( 800)
408 ( 900)
454 (1000)
0
136 ( 300)
182 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
363 ( 800)
ppm
0
8.1
9.9
12.0
14.0
16.7
19.1
21.2
0
6.5
8.7
10.8
12.5
15.2
18.2
Ammonia addition
Kg/day (#/day)
0
0
0
0
0
0
0
0
0
87 (192)
87 (192)
87 (192)
87 (192)
87 (192)
87 (192)
7. of
reca
0
0
0
0
0
0
0
0
0
264
197
158
132
113
99
Eff
PH
6.7
6.4
6.3
6.3
6.3
6.3
6.2
6.2
6.7
6.7
6.6
6.5
6.5
6.4
6.3
Chlorine
re s id , ppm
5 Min
__b
--
._
-_
_.
..
--
--
--
--
Hr
--
--
--
--
--
--
_.
0
0
0
0
0
0
0
Motile
sp/field
@ 2 hr
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0
0.01-0.1
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.01-0.10
0
Ul
Oi
aPercent of the NH/*" required to neutralize the HC1 produced from the hydrolysis of
b -- Not determined.
-------
Table Vll(continued). EFFECT OF AMMONIA ADDITION ON CHLORINE ACTIVITY IN MILL SYSTEM
Date
(1972)
May 18
Chlorine
addition
Kfc/day (#/day)
0
91 ( 200)
136 ( 300)
182 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
363 ( 800)
408 ( 900)
454 (1000)
0
91 ( 200)
136 ( 300)
182 ( 400)
227 ( 500)
136 ( 300)
182 ( 400)
227 ( 500)
272 ( 600)
363 ( 800)
ppm
0
4.1
6.2
8.2
10.5
12.8
14.9
17.0
19.2
21.2
0
3.9
5.8
7.2
9.1
6.5
8.6
10.4
12.5
16.3
Ammonia addition
Ka/day (#/day)
0
0
0
0
0
0
0
0
0
0
92 (202)
92 (202)
92 (202)
92 (202)
92 (202)
65 (144)
65 (144)
65 (144)
65 (144)
65 (144)
% of
reqa
0
0
0
0
0
0
0
0
0
0
--
415
277
208
166
197
148
118
99
74
Eff
PH
6.6
6.5
6.5
6.5
6.4
6.3
6.2
6.2
6.1
6.1
6.8
6.7
6.6
6.5
6.5
6.6
6.6
6.5
6.4
6.4
Chlorine
resid.
5 Min
__b
--
--
--
--
--
--
--
--
--
--
--
--
--
--
*
ppm
Hr
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.42
0.42
0.42
Motile
sp/field
@ 2 hr
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0
ro
aPercent of the NH^+ required to neutralize the HC1 produced from the hydrolysis of
b -- Not determined.
-------
Table Vll(continued). EFFECT OF AMMONIA ADDITION ON CHLORINE ACTIVITY IN MILL SYSTEM
Date
(1972)
May 19
Chlorine
addition
KR/day (#/day)
0
91 ( 200)
136 ( 300)
182 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
363 ( 800)
408 ( 900)
454 (1000)
0
91 ( 200)
136 ( 300)
182 ( 400)
227 ( 500)
272 ( 600)
318 ( 700)
363 ( 800)
408 ( 900)
454 (1000)
ppm
0
4.0
6.0
7.8
9.6
11.0
12.9
14.8
17.0
19.2
0
4.4
6.6
9,0
11.5
13.8
16.5
18.6
19.8
21.7
Ammonia addition
Kg/day (#/day)
0
0
0
0
0
0
0
0
0
0
93 (204)
93 (204)
93 (204)
93 (204)
93 (204)
93 (204)
93 (204)
93 (204)
93 (204)
93 (204)
apercent of the NH^ required to neutralize the HC1
7. of
reqa
0
0
0
0
0
0
0
0
0
0
--
420
280
210
168
140
120
105
93
84
Eff
PH
7.4
7.3
7.2
7.2
7.2
7.1
7.1
7.0
7.0
6.9
7.3
7.5
7.4
7.4
7.3
7.2
7.2
7.1
7.1
7.0
Chlorine
res id, ppm
5 Min
0
0
0
o b
D
0.86
1.3
1.3
1.7
1.7
0
0.86
1.30
1.70
3.00
2.60
3.40
3.40
3.90
4.30
Hr
0
0
0
0
--
0
0
0
0
0.43
0
0
0
0
0
0.43
0.43
0.43
0.86
0.86
Motile
sp/ field
@ 2 hr
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0.1-1.0
0
0
0
0
produced from the hydrolysis of C^.
b Not determined.
tNJ
Ul
-------
Table VIII. RESULTS FROM MONITORING OF FULL SCALE CHLORINATION
Date
(1972)
July 18
19
20
21
22
23
24
25
26
27
ฃ 27
28
31
Aug. 2
3
4
7
7
8
9
10
11
14
15
Additives
Chlorine
Kg/day (#/day)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
ppm
4.9
6.1
4.8
5.0
4.3
5.0
5.0
5.2
6.1
10.0
6.6
6.1
6.0
6.1
6.0
5.1
4.2
5.4
5.8
6.4
6.4
5.4
5.3
5.4
NaOH (100%)
Kg/day (#/day)
133 (288)
133 (288)
98 (216)
98 (216)
82 (180)
98 (216)
98 (216)
114 (252)
133 (288)
98 (216)
82 (180)
98 (216)
73 (362)
82 (180)
82 (180)
82 (180)
90 (198)
90 (198)
98 (216)
82 (ISO)
82 (180)
82 (180)
82 (180)
82 (180)
Effluent
flow
L/sec (TGH)
268 (255)
215 (205)
273 (260)
262 (250)
304 (290)
262 (250)
262 (250)
250 (240)
215 (205)
131 (125)
200 (190)
215 (205)
220 (210)
215 (205)
220 (210)
257 (245)
315 (300)
242 (230)
226 (215)
205 (195)
205 (195)
242 (230)
247 (235)
242 (230)
PH
inj
Hฃ
12.1
12.1
11.8
11.8
11.8
11.8
11.8
11.8
11.8
11.7
11.7
12,0
11.9
12.1
12.2
12.1
12.4
11.9
11.9
11.9
11.9
11.9
12.1
12.1
Effluent
Ini
__b
--
6.4
6.6
6.6
6.6
6.8
6.9
7.0
--
--
--
6.8
--
6.8
6.9
6.8
--
6.8
6.7
6.7
6.7
7.3
7.3
Fin
..
6.6
6.4
6.6
6.6
6.7
6.8
7.1
--
--
--
6.7
6.8
6.9
7.0
6.9
--
6.9
6.8
6.8
6.8
7.3
7.2
Inject.
H20 press.
kg/cm2 Win/)
4.9 (70)
4.2 (60)
4.9 (70)
4.9 (70)
4.9 (70)
4.9 (70)
4.9 (70)
4.9 (70)
A. 9 (70)
4.9 (70)
4.9 (70)
4.9 (70)
4.2 (60)
5.1 (72)
4.6 (65)
4.8 (68)
1.1 (15)
4.9 (70)
4.2 (60)
4.9 (70)
5.1 (72)
4.9 (70)
4.9 (70)
4.9 (70)
Motile
sp/field
& 2 hrs
0
0
0.01-0.10
0
0
0
0
0
--
0
0
0
0
0
0
0
0
0
--
0
0
0
0
0
Total resid
Cl, ppma
5 Min
+
+
2.6
1.2
+
+
+
2.1
--
--
3.0
2.0
2.8
3.3
1.8
1.1
1.0
2.1
2.4
2.0
2.0
2.2
2.7
2.2
2 Hr
0
0
0
0.5
0
0
0
0
--
1.2
0
0
1.2
0.7
0.7
0
0
0
--
0.5
0.5
0
0
0
Residual present but concentration not determined.
b ซ Not determined.
-------
Table VIII (continued). RESULTS FROM MONITORING OF FULL SCALE CHLORINATIOH
Bate
(1972)
Aug. 16
17
17
18
20
22
23
24
28
29
29
31
Sept. 8
14
14
14
15
17
17
19
19
20
20
Additives
Chlorine
Ks/dav (#/day)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
cpm
4.7
7.6
6.1
6.0
5.6
5.4
6.0
5.4
5.8
6.2
5.4
6.0
5.3
5.4
5.4
5.4
5.3
5.1
0
4.6
0
4,8
0
NaOH (100%)
K.R/day (#/day)
82 (180)
82 (180)
82 (180)
82 (180)
82 (180)
82 (180)
82 (162)
82 (180)
82 (180)
82 (180)
82 (180)
82 (180)
180 (396)
24 ( 54)
33 ( 72)
139 (306)
65 (144)
65 (144)
0 ( 0)
65 (144)
0 { 0)
65 (144)
0 ( 0)
Effluent
flow
L/sec (TGH)
278 (265)
173 <165)
215 <205)
220 (210)
236 (225)
242 (230)
220 (210)
242 (230)
226 (215)
210 (200)
242 (230)
220 (210)
247 (235)
242 (230)
242 (230)
242 (230)
247 (235)
257 (245)
257 (245)
284 (270)
284 (270)
273 (260)
273 (260)
Inj
H-,0
11.9
12.1
12.1
11.9
11.9
11.9
11.9
11.9
11.9
11.9
11.9
12.1
11.3
11.7
13.2
12.2
12.2
12.2
--
12.2
-~
PH
Effluent
Ini
6.7
7.2
--
7.3
7.3
--
--
7.3
--
--
7.1
7.1
7.0
7.0
7.1
7.1
Fin
6.8
7.2
7.2
7.3
7.2
--
7.2
7.3
7.2
7.0
7.0
7.0
7.6
7.0
7.1
--
7.0
--
7.1
"
Inject.
HjO press.
ka/cm2 (#/in.2)
4.9 (70)
4.9 (70)
4.9 (70)
4.6 (65)
4.6 (65)
4.6 (65)
4.6 (65)
4.2 (60)
4.6 (65)
4.6 (65)
4.6 (65)
4.6 (65)
3.0 (43)
3.2 (45)
3.2 (45)
1.6 (23)
3.2 (45)
3.2 (45)
3.2 (45)
3.5 (50)
3.5 (50)
3.4 (48)
3.4 (48)
Motile
sp/field
(3 2 hrs
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1.0-10.0
0
1.0-10.0
0
1.0-10.0
Total
Cl. i
5 Mln
2.1
3.8
3.2
2.8
4.0
2.7
1.9
2.3
2.8
2.1
2.8
2.6
2.4
2.1
2.7
3.6
2.6
2.7
1.7
2.7
2.0
2.1
1.3
re sid
2 Hr
0
1.6
0.3
0
1.0
0.3
0
1.2
0
0
0
0
0
1.5
1.9
2.2
2.2
2.3
1.6
2,0
2.2
1.4
1.2
Residual present but concentration not determined.
determined.
-------
Table VIII (continued). RESULTS FROM MONITORING OF FULL SCALE CHLORINATION
Date
(1972)
Sept. 22
22
26
26
29
29
Oct. 2
2
5
5
7
7
9
9
10
10
11
11
13
13
16
16
17
17
Additives
Chlorine
Kg/day (#/dav)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
ppm
10.0
0
6.2
0
5.4
0
5.2
0
6.4
0
6.0
0
5.2
0
6.4
0
5.8
0
6.0
0
6.6
0
6.2
0
NaOH (100%)
Kg7day (#/day)
71 (156)
0 ( 0)
65 (144)
0 ( 0)
( --)
0 ( 0)
59 (130)
0 ( 0)
72 (158)
0 ( 0)
59 (130)
0 ( 0)
65 (144)
0 ( 0)
59 (130)
0 ( 0)
65 (U4)
0 ( 0)
72 (158)
0 ( 0)
65 (144)
0 ( 0)
59 (130)
0 ( 0)
Effluent
flov
L/sec (TGH)
131 (125)
131 (125)
210 (200)
210 (200)
242 (230)
242 (230)
252 (240)
252 (240)
205 (195)
205 (195)
217 (207)
217 (207)
252 (240)
252 (240)
205 (195)
205 (195)
226 (215)
226 (215)
220 (210)
220 (210)
200 (190)
200 (190)
210 (200)
210 (200)
PH
InJ
H^
12.3
...
12.2
12.1
__
12.1
12.2
12.2
12.2
--
12.3
12.3
12.2
12.3
--
12.2
" "*
Effluent
Ini
7.0
7.0
7.0
7.0
6.9
6.9
6.9
6.9
7.0
7.0
7.0
7.0
7.0
7.0
7.2
7.2
7.0
7.0
6.9
6.9
6.9
6.9
7.1
7.1
Fin
7.0
.,
7.0
--
7.0
--
6.9
..
7.0
-.
7.0
--
7.0
--
7.2
--
7.0
--
7.0
--
7.1
--
7.1
- .
Inject.
H~0 press.
kg/cm2 (#/ln?)
3.4 (48)
3.4 (48)
3.0 (43)
3.0 (43)
3.2 (45)
3.2 (45)
3.0 (42)
3.0 (42)
3.2 (46)
3.2 (46)
3.2 (45)
3.2 (45)
2.8 (40)
2.8 (40)
2.8 (40)
2.8 (40)
3.0 (43)
3.0 (43)
2.8 (40)
2.8 (40)
2.8 (40)
2.8 (40)
2.8 (40)
2.8 (40)
Motile
sp/field
@ 2 hrs
0
1.0-10.0
0
1.0-10.0
0
1.0-10.0
0
0.1-1.0
0
0.1-1.0
0
0.1-1.0
0
1.0-10.0
0
1.0-10.0
0
1.0-10.0
0
1.0-10.0
0
1.0-10.0
0
1.0-10.0
Total resid
Cl. ppma
5 Min
6.4
0
2.7
1.7
1.6
0
2.3
1.6
2.1
0
2.4
0
2.0
0
2.6
0
2.1
0
1.6
0
1.6
0
1.6
0
2 Hr
2.9
0
1.3
0.9
0.7
0
0.7
1.0
0.8
0
0.7
0
0.3
0
0.7
0
0
0
0
0
0
0
0
0
Residual present but concentration not determined.
b -- Not determined.
-------
Table VIII (continued). RESULTS FROM MONITORING OF FULL SCALE CHLORINATION
Date
(1972)
Oct. 18
18
19
19
23
23
25
25
27
27
31
31
Nov. 1
1
6
6
8
8
9
9
13
13
Additives
Chlorine
Kg/day (#/day)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
ppm
6.0
0
5.7
0
6.8
0
6.0
0
5.7
0
5.8
0
5.6
0
6.4
0
6.9
0
6.1
0
7.1
0
NaOH (100%)
Kg/day (#/day)
33 ( 72)
0 ( 0)
59 (130)
0 ( 0)
( ")
0 ( 0)
78 (173)
0 ( 0)
72 (159)
0 ( 0)
72 (159)
0 ( 0)
72 (159)
0 ( 0)
65 (143)
0 ( 0)
72 (159)
0 ( 0)
69 (151)
0 ( 0)
( ")
0 ( 0)
Effluent
flow
L/sec (TGH)
220 (210)
220 (210)
231 (220)
231 (220)
194 (185)
194 (185)
220 (210)
220 (210)
231 (220)
231 (220)
226 (215)
226 (215)
236 (225)
236 (225)
205 (195)
205 (195)
189 (180)
189 (180)
215 (205)
215 (205)
184 (175)
184 (175)
PH
InJ
H2ฐ
12. Ov
__b
12.2
12.2
12.4
12.2
12.4
--
12.4
12.2
12.4
--
12.3
--
12-13
~"
Effluent
Ini
7.1
7.1
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
6.8
6.8
6.8
6.8
6.7
6.7
6.9
6.9
Fin
7.1
--
7.0
7.0
7.0
7.0
--
7.0
7.0
6.8
--
6.8
6.8
--
7.6
~ ~
Inject.
VUG press.
kg/cm2 (#/in.2)
2.8 (40)
2.8 (40)
2.8 (40)
2.8 (40)
2.8 (40)
2.8 (40)
2.8 (40)
2.8 (40)
3.4 (48)
3.4 (48)
3.2 (45)
3.2 (45)
2.8 (40)
2.8 (40)
2.8 (40)
2.8 (40)
2.6 (37)
2.6 (37)
2.6 (37)
2.6 (37)
2.6 (37)
2.6 (37)
Motile
sp/ฃield
-------
Table VIII (continued). RESULTS FROM MONITORING OF FULL SCALE CHLORINATION
Date
(1972)
Nov. 13
13
16
16
25
25
Mean
S.D.
Var., X
# of Samp
+ Rasia
Additive
Chlorine
Kjz/day f#/dav)
113 (250)
0 ( 0)
113 (250)
0 ( 0)
113 (250)
0 C 0)
113 (250)
0
0
70
DDO
7.1
0
6.0
0
6.8
0
5.9
1.0
17
70
NaOH (100X)
Ks/day <#/day)
( --)
0 ( 0)
72 (159)
0 ( 0)
72 (159)
0 ( 0)
81 (178)
30 ( 66)
37
66
ual present but concentration not determ
Effluent
flow
L/aec (TGH)
184 (175)
184 (175)
220 (210)
220 (210)
194 (185)
194 (185)
228 (217)
33 ( 31)
14
70
oH
Inj
HJO
12-13
--
12.5
--
12.9
.-
12.1
0.3
--
70
Effluent
Inl
6.6
6.6
7.0
7.0
7.0
7.0
6.9
0.2
--
50
Fin
7.7
.-
7.1
_.
7.2
_.
7.0
0.2
--
50
Inject.
HjO prett.
kg/cm2 (#/in?)
2.6 (37)
2.6 (37)
2.4 (34)
2.4 (34)
1.4 (20)
1.4 (20)
3.8 (54)
1.1 (15)
28
70
Motile
p/field
@ 2 hra
0
0.1-1.0
0
1.0-10.0
0
1.0-10.0
ฃ0.01
<0.001
40.1
70
Total reaid
Cl. p
5 Mln
2.7
0
2.4
0
1.8
0
2.4
0.8
33
63
pma
2 Hr
0.6
0
0.6
0
0
0
1.4
1.1
79
63
ned.
-- Mot determined.
-------
Table IX. EFFECT OF CHLORINATION ON RECEIVING WATERS
Analysis
and
sample point*
ฃH
Cement plant
M.S. bridge
M.S. mouth
Pipe xng.
Sand. Bridge
D.O. ppm
Cement plant
M.S. bridge
M.S. mouth
Pipe xng.
Sand, bridge
Temp. ฐC
Cement plant
M.S. bridge
M.S. mouth
Pipe xng.
Sand, bridge
Cl resid. ppm
Cement plant
M.S. bridge
M.S. mouth
Pipe xng.
Sand, bridge
Colifonns/100 ml
Cement plant
M.S. bridge
M.S. mouth
Pipe xng.
Sand, bridge
Unchlorinated effluent
June 119721
12
__b
6.9
7.1
6.5
2.6
18.6
22.5
0
0
6.60
6.46
13
6.9
6.9
6.3
1.4
20.4
22.8
0
0
6.48
6.20
15
6.3
6.4
3.6
0.4
25.0
24.3
0
0
6.78
6.85
20
6.4
6.8
6.9
5.4
21.0
21.3
0
0
6.70
6.23
27
7.3
7.4
--
18.8
20.4
0
0
7.15
7.04
Chlorinated eff
June (1972)
28
7.2
6.9
7.0
--
21.0
24.5
18.8
--
4.48
5.18
3.56
30
6.7
4.8
--
27.0
29.2
--
6.04
5.00
No Cl
July
7
7.2
6.4
6.4
7.1
--
16.5
22.0
22.0
16.8
--
2.11
6.32
6.12
4.36
aSee last page of table.
b -- Not determined.
-------
Table IX (continued). EFFECT OF CHLORINATION ON RECEIVING WATERS
Analysis
and
sample point8
E3
Cement plant
M.S. bridge
M.S. mouth
Pipe xng,
Sand, bridge
D.O. ppm
Cement plant
M.S. bridge
M.S. mouth
Pipe xng.
Sand, bridge
Temp.--ฐC.
Cement plant
M.S. bridge
M.S. mouth
Pipe xng.
Sand, bridge
Cl resid.--ppm
Cement plant
M.S. bridge
M.S. mouth
Pipe xng.
Sand, bridge
Coliforms/100 ml
--LogJO
Cement plant
M.S. bridge
M.S. mouth
Pipe xng.
Sand bridge
Chlorinated effluent
July
8
7.4
6.7
6.6
7.2
_.
--
--
.-
..
_.
16.0
22.0
21.8
16.5
--
--
--
..
--
--
2.15
6.00
5.90
4.49
--
18
7.1
7.3
7.0
7.1
7.5
10.0
5.8
1.2
7.7
10.2
20.6
25.6
24.8
22.0
23.7
..
--
0
_.
--
2.00
5.43
6.60
4.72
4.81
19
.-
..
--
.-
10.4
6.5
0.9
4.9
9.0
21.0
24.8
27.8
20.8
23.9
--
--
0
_-
--
2.20
4.85
5.49
4.28
3.78
2
[1972
8.2
7.0
7
8
8
10
4
3
9
8
20
25
23
20
22
1
0
1
1
0
1
3
4
3
4
.2
.2
1
3
7
7
1
9
6
0
6
6
8
7
9
1
2
7
48
62
60
84
04
25
7.4
7.3
7.2
7.2
7.2
10.5
9.0
6.0
8.6
8.4
16.3
18.0
18.0
17.6
18.0
1.3
0
0
0.5
0.5
1.60
2.85
4.51
2.90
2.48
27
7.7
7.0
7.7
7.0
6.9
10.6
7.6
0.4
8.4
8.2
18.0
21.0
26.5
18.5
21.5
1.2
0
0
0.7
0.7
1.00
6.73
7.08
4.23
4.38
31
7.6
7.3
7.1
7.4
7.2
10.9
7.0
3.0
9.3
9.1
20.8
24.0
24.0
20.4
21.9
0.5
0
0
0.5
0.4
1.48
2.70
4.20
2.70
2.00
Aug.
3
7.4
7.3
7.0
7.4
7.2
10.0
7.5
3.5
9.5
9.4
20.0
23.0
24.0
19.0
21.0
3.6
1.0
0.3
0.7
1.1
1.78
3.78
3.85
2.70
2.45
ฃSee last page of table.
-- Not determined.
-------
Table IX (continued). EFFECT Of" CHLORINATION ON RECEIVING WATERS
Analysis
and
sample point8
ฃH
Cement plant
M.S. bridge
M.S. mouth
Pipe xng.
Sand, bridge
D.,0 . --ppm
Cement plant
M.S. bridge
M.S. mouth
Pipe xng.
Sand, bridge
Temp.--ฐC.
Cement plant
M.S. bridge
M.S. mouth
Pipe xng.
Sand , bridge
C'l res id. --ppm
Cement plant
M.S. bridge
M.S. mouth
I'ipe xng.
Sand, bridge
Coli forms/100 ml
Cement plant
M.S. bridge
M.S. mouth
Pipe xng.
Sand, bridge
Chlorinated effluent
August (1972)
8
7.2
7.0
6.8
7.1
7.1
9.9
5.0
1.3
8.6
8.2
23.0
26. A
29.4
23.8
24.8
0
0.8
0
0.9
1 .6
1 .60
2.30
4.78
2.32
2.38
11
6.9
6.8
6.9
7.0
7.0
10.8
7.6
5.2
10.8
10.8
15,6
19.9
19.6
16.0
17.0
0
0
0
0
0.4
2.15
4.00
3.48
2.70
2.57
16
7.4
7.2
7.2
7.3
7.3
11.4
7.0
3.3
10.8
10.8
15.8
20.0
18.8
16.8
17.0
0
0
0
0
0
2.75
3.61
4.18
2.56
2.78
18
__b
7.2
7.4
7.5
9.0
7.1
10.6
16.0
15.6
15.6
0
0
0
2.95
4.30
2.28
24
7.1
7.6
7.3
7.1
7.1
10.4
7.1
1 .5
9.6
9.3
13.7
19.9
18.4
14.7
14.9
0
0
0
0
0
2.46
3.51
6.51
4.93
3.42
29
--
;;
--
ป
1.95
3.08
2.11
1.70
30
7.7
7.2
7.6
7.6
\
--
--
1.70
2.30
2.23
2.11
31
7.9
7.4
7.9
7.8
;;
--
ซ. _
1.85
1.90
2.04
2.?0
ro
e^
Ul
Cement Plant--Upstream control.
Mark Slough (M.S.) Bridge--305 M (334 yd.) downstream.
M.S. Mouth--!.22 Km (1334 yd.) downstream of effluent discharge.
Pipeline Crossing (Pipe xng.)--4.83 Km (3 mi.) downstream.
Sandersons (Sand.) Bridge--12.9 Km (8 mi.) downstream.
b-- Not determined.
-------
Table X. CONTINUOUS TOXICITY TEST WITH STEELHEAD TROUT.
EXPERIMENT 1
Measurement and
sampling point
Chlorine added, ppm
Fish killed, %
Ch 1 Water control
4 Unchlor eff, 67%
5 Unchlor eff, 50%
6 Chlor eff, 50%
pH
Ch 1
4
5
6 G
Temp, UC
Ch 1
4
5
6
D.O., ppm
Ch 1
4
5
6
Total resid Cl, ppm
Chlor eff headbox
Coliforms/100 ml
Chlor eff headbox
Inh. of > uptake, %
A^ing box*"
Coliform reduction, %
Aging box
a
Elapsed time^ days
Start
10
0
0
0
0
7.1
6.9
7.0
7.1
7.0
7.1
7.2
7.3
11.8
8.9
10.0
8.9
+b
1100
88
99.997
1
10-203
0
100
0
100
7.0
7.1
7.2
7.3
12.5
19.1
17.0
17.0
10.8
8.7
9.4
9.4
__c
--
2 1 3 | 4
Test was
stopped
after
1 day
A partially plugged effluent delivery tube caused high
chlorine concentrations.
^Residual present but concentration not determined.
c Not determined.
266
-------
Table XI. CONTINUOUS TOXICITY TEST WITH STEELHEAD TROUT.
EXPERIMENT 2
Measurement and
sampling point
Chlorine added, ppm
Fish killed, %
Ch 1 Water control
2 Chlor eff, 5%
3 Chlor eff, 10%
4 Chlor eff, 207.
5 Chlor eff, 407o
6 Unchlor eff, 50%
ฃH
Ch 1
2
3
4
5
6
Temp , UC
Ch 1
2
3
4
5
6
D.O., ppm
Ch 1
2
3
4
5
6
Total resid Cl, ppm
Chlor eff headbox
Coliforms/100 ml
Chlor eff headbox
Inh of 0ซ uptake, %
Aging box
Coliform reduction^ %
Aging box
Elapsed time, days
Start
10
0
0
0
0
0
0
a
--
--
..
92
--
1
10
0
0
0
60
100
70
7.6
7.6
7.5
7.5
7.5
7.4
9.0
9.4
9.7
10.8
12.6
14.1
11.6
11.6
11.5
11.2
10.6
10.0
1.5
99
--
2
10
0
0
0
100
100
100
7.5
7.5
7.4
7.5
7.6
7.6
8.0
8.3
8.9
9.5
11.0
12.7
12.1
11.9
11.8
11.6
11.2
10.8
1.9
100
98
99.999
3
10
0
0
10
100
100
100
7.6
7.5
7.5
7.5
7.5
7.4
14.2
13.2
11.4
10.5
10.1
9.6
10.2
10.4
10.8
11.2
11.5
11.8
1.7
__
95
--
4
10
0
0
30
100
100
100
7.2
7.2
7.3
7.3
7.4
7.2
9.0
9.2
9.4
10.3
12.0
13.5
12.1
11.9
11.6
11.4
10.9
10.2
2.4
..
97
--
a -- Not determined.
267
-------
Table XII. CONTINUOUS TOXICITY TEST WITH SOCKEYE SALMON
EXPERIMENT 3
Measurement and
sampling point
Chlorine added, ppm
Fish Killed, %
Ch 1 Water control
2 Chlor eff, 5%
3 Chlor eff, 10%
4 Chlor eff, 20%
5 Chlor eff --imaged, 20%
21
Ch 1
2
3
4
5
Temp , UC
Ch 1
2
3
4
5
D.O. , ppm
Ch 1 No readings taken
2 because of
3 defective probe.
4
5
Total resid Cl, ppm
Chlor eff headbox
Coli forms/ 100 ml
Chlor eff headbox
Inh of 0ซ uptake, %
Aging box
Coliform reduction, 7ป
Aging box
Elapsed time, days
3.5
Hrs
4.1
0
0
0
0
25
7.6
7.5
7.4
7.1
7.0
17.1
17.5
18.0
19.0
19.0
;;
0
..
..
--
1
6.9
0
0
0
0
100
7.1
7.0
6.9
6.7
7.0
17.8
18.0
18.3
20.0
20.0
I
0
--
2
5.5
0
0
0
0
100
7.0
7.0
6.9
6.8
18.1
18.4
18.8
21.0
--
0
3
a
--
--
--
;;
4
tm
--
-
--
3 -- Not determined.
268
-------
Table XIII.
CONTINUOUS TOXICITY TEST WITH SOCKEYE SALMON.
EXPERIMENT 4
Measurement and
sampling point
Chlorine added, ppm
Fish killed, %
Ch 1 Water control
2 Chlor eff, 5%
3 Chlor eff, 10%
4 Chlor eff, 20%
ฃH
Ch 1
2
3
4
Temp, "C
Ch 1
2
3
4
D.O., ppm
Ch 1
2
3
4
Total res id Cl, ppm
Chlor eff headbox
Coliforms/100 ml
Chlor eff headbox
Inh of On uptake, %
Aeine box*"
Coliform reduction, 7,
Aging box
Elapsed time, days
1
5.8
0
0
0
0
7.3
7.2
7.2
7.2
20.7
20.7
20.8
21.4
8.8
8.8
8.8
8.6
0
._
90
__
2
6.4
0
5
0
0
7.3
7.3
7.3
7.3
18.7
18.7
18.9
19.8
9.6
9.6
9.6
9.2
0.5
91
--
3
5.4
0
5
0
0
7.3
7.3
7.3
7.3
17.8
17.9
18.2
19.2
10.4
10.4
10.2
9.8
0
Z. 100
88
99.999
4
5.8
0
5
0
0
__a
--
--
_ _
__
__
--
a -- Not determined.
269
-------
Table XIV. CONTINUOUS TOXICITY TEST WITH SOCKEYE SALMON.
EXPERIMENT 5
Measurement and
sampling point
Chlorine added, ppm
Fish killed. %
Ch 1 Water control
2 Chlor eff, 57.
3 Chlor eff, 10%
4 Chlor eff, 20%
ฃH
Ch 1
2
3
4
Temp f t
Ch 1
2
3
4
D.O. , ppm
Ch 1
2
3
4
Total resid Cl, ppm
Chlor eff headbox
Colif onus/ 100 ml
Chlor eff headbox
Inh of 0^ uptake, %
Aging Box^
Coliform reduction, %
Aging box
Elapsed time, days
0.3
4.4
0
0
0
0
7.7
7.7
7.7
7.6
17.3
17.5
17.8
19.0
--
0
..
1
4.5
0
0
0
0
7.6
7.6
7.6
7.4
17.3
17.6
17.8
18.1
0
2
4.7
0
0
0
0
a
--
3
6.3
0
0
0
5
7.8
7.6
7.5
7.4
15.7
16.0
16.8
17.8
10.4
10.4
10.2
9.3
0.8
^.100
65
99.999
a -- Not determined.
4
6.0
0
0
0
5
--
--
__
270
-------
Table XV. CONTINUOUS TOXICITY TEST WITH SOCKEYE SALMON.
EXPERIMENT 6
Measurement and
sampling point
Chlorine added, ppm
Fish killed, %
Ch 1 Water control
2 Chlor eff, 5%
3 Chlor eff, 10%
4 Chlor eff, 207ซ
ฃH
Ch 1
2
3
4
Temp, ฐC
Ch 1
2
3
4
D.O., ppm
Ch 1
2
3
4
Total res id Cl, ppm
Chlor eff headbox
Coli forms/ 100 ml
Chlor eff headbox
Inh of On uptake, %
Aging box
Coliform reduction, 7,
Aging box
Elapsed time, days
0.1
3.9
0
0
0
0
--
16.0
16.9
17.0
18.0
11.0
11.0
10.6
10.2
0
85
1
a
0
0
0
0
--
--
--
._
--
2
4.5
0
0
0
0
7.7
7.7
7.7
7.6
15.1
15.4
16.2
17.4
10.9
10.9
10.7
10.1
0.3
95
--
3
5.0
0
0
0
0
7.7
7.7
7.7
7.6
15.9
16.1
16.8
17.7
10.9
10.9
10.6
10.0
0
100
94
99.999
4
5.4
0
0
0
0
--
--
_ _
*
_ ..
--
a Not determined.
271
-------
Table XVI. CONTINUOUS TOXICITY TEST WITH SOCKEYE SALMON.
EXPERIMENT 7
Measurement and
sampling point
Chlorine added, ppm
Fish killed, 7,
Ch 1 Water control
2 Chlor eff, 5%
3 Chlor eff, 10%
4 Chlor eff. 20%
pH
Ch 1
2
3
4
Temp, "C
Ch 1
2
3
4
D.O., ppm
Ch 1
2
3
4
Total resid Cl, ppjn
Chlor eff headbox
Colif orms/100 ml
Chlor eff headbox
Inh of 0,, uptake, %
Aging box^"
Coliform reduction, %
Aging box
Elapsed time, days
1
4.5
0
0
0
0
7.9
7.9
7.8
7.8
16.0
17.2
17.4
18.2
10.6
10.2
10.2
9.8
0
__
88
2
a
0
0
0
0
--
--
--
--
3
5.0
0
0
0
0
7.6
7.6
7.6
7.5
14.7
15.8
16.0
16.8
10.4
10.2
10.2
9.6
0
210
90
99.999
4
0
0
0
0
. _
--
_ _
-- Not determined.
272
-------
SECTION XVIII
INDEX
SECTION I
CONCLUSIONS 1
SECTION II
RECOMMENDATIONS 7
SECTION III
INTRODUCTION 9
SECTION IV
APPARATUS AND METHODS 10
ENUMERATION OF BACTERIA 10
Total Bacteria
Coliforms 10
Multiple Tube (MT) -- 10
Membrane Filter (MF) -- 10
MILL PRODUCTION AND WASTE TREATMENT ll
Production
Waste Treatment
273
-------
Page
Spent Sulfite Cooking Liquor 11
Primary Treatment -- 11
Secondary Treatment -- 11
SMALL SCALE WASTE TREATMENT 12
Equipment 12
Flow Sequence and Control 12
Monitoring 13
Start Up Procedure 14
ANALYTICAL METHODS 14
Total Residual Chlorine 14
Dissolved Oxygen 14
SAMPLING 15
FISH TOXICITY STUDIES 15
Apparatus (Figures 46 and 47) 15
Flow Sequence and Control 15
Handling of Fish 16
SECTION V
EVALUATION OF METHODS FOR ENUMERATING COLIFORMS 17
COMPARISON OF MF AND MT TESTS 17
REPRODUCIBILITY OF RESULTS 26
EXPERIMENTAL POUR PLATE PROCEDURE 30
274
-------
Page
SECTION VI
BACTERIA IN AERATED STABILIZATION BASINS 34
CONCENTRATIONS 34
TYPES 38
SECTION VII
EFFECT OF VARIABLES ON CONCENTRATIONS OF BACTERIA
IN SECONDARY EFFLUENT 42
INOCULATION 42
Aerated Basins 42
Small Scale System 48
pH 56
Direct Effects 56
Indirect Effects 58
TEMPERATURE 63
DISSOLVED OXYGEN 63
Aerated Basins 63
Small Scale System 63
EPA Unit 71
Sediments 73
BOD
76
SERIES VS PARALLEL POND OPERATION 76
275
-------
Page
RETENTION TIME IN SMALL SCALE SYSTEM 84
INTERACTIONS 87
SECTION VIII
ROLE OF COLIFORMS IN BOD REDUCTION 89
SECTION IX
SOURCES OF COLIFORMS 92
MILL SURVEYS 92
RECYCLE SYSTEMS 93
SANITARY WASTES 97
SECTION X
ACTIVITY OF CHLORINE IN SECONDARY WASTES 99
INITIAL EVALUATION OF BACTERICIDAL ACTIVITY 99
EFFECT OF DILUTION 103
METHODS FOR EVALUATING CHLORINE ACTIVITY 103
Motillty Test 107
Inhibition of Oxygen Uptake 107
5 Minute Residuals 109
FACTORS AFFECTING CHLORINE ACTIVITY IN LABORATORY TESTS 109
109
276
-------
Page
Oxygen Uptake 109
Motillty 115
Chlorine Residuals -- 115
Chlorine Concentration 124
Dissolved Oxygen 129
Sulfite 129
Carbohydrates 135
Particulates 136
Lignosulfonates 137
SECTION XI
FULL SCALE CHLORINATION 140
DESCRIPTION OF CHLORINATING SYSTEM 140
EFFECT OF NaOH ADDITION ON CHLORINE ACTIVITY 142
CAUSTIC REQUIREMENTS FOR IMPROVED CHLORINATION 146
EFFECT OF AMMONIA ADDITION ON CHLORINE ACTIVITY 150
MODIFIED MILL CHLORINATION SYSTEM FOR USING CAUSTIC 154
METHODS FOR MONITORING CHLORINATION 155
Oxygen Uptake Test 155
Motility Test 156
5 Minute Residual Test 156
Interference by Nitrite and Iron 158
Formation of Nitrite 161
Significance of Nitrite 165
pH Measurements 166
277
-------
Page
FACTORS AFFECTING FULL SCALE CHLORINATION 166
Concentrations of Lignosulfonates 166
Series vs Parallel Operation 168
Injector Water Pressure 169
Effluent Flow Rate 171
Chlorine Addition Rate Increases in Response to Greater
Effluent Flow Rate 172
Chlorine Addition Rate Decreases in Response to Reduced
Effluent Floy 172
Primary Pond Operation 173
MONITORING OF FULL SCALE CHLORINATION 174
Procedure 174
Chlorine^Appllcatlon Rate 175
Caustic Delivery Rate 175
Bactericidal Activity 175
Factors Contributing to 2 Hour Chlorine Residuals 176
EFFECT OF CHLORINATION ON RECEIVING WATERS 181
Procedure 181
Collforms 181
Dissolved Oxygen 186
ฃH 188
Chlorine Residuals 190
SECTION XII
FATE OF CHLORINE ADDED TO SECONDARY EFFLUENT 191
ANALYTICAL METHODS 192
FORMATION AND STABILITY OF VARIOUS FORMS OF CHLORINE 194
278
-------
Page
DURATION OF BACTERICIDAL ACTIVITY 195
Effect on Oxygen Uptake 195
Effect on Reproduction 197
Effect on Motillty 197
SECTION XIII
FISH TOXICITY OF CHLORINATED EFFLUENTS 201
STATIC LABORATORY TESTS 201
Procedure 201
Tests with Gambusia 201
Tests with Guppies (Lebistes retlculatus) 201
Aerated Effluent -- 201
Non-Aerated Effluent 202
Effect of Aeration on Toxicity -- 205
Toxicity of Chlorine and Chloramine -- 207
Comparison of Chlorine Toxicity In Water and in Effluent -- 208
Inactivation of Chlorine Toxicity by Effluent 208
CONTINUOUS FLOW FIELD TESTS 210
Methods and Equipment 210
Chlorination 210
Aging of Chlorinated Effluent -- 213
Dilution of Aged Chlorinated Effluent 213
Evaluation of Fish Toxicity 213
Evaluation of Bactericidal Activity -- 213
Results 214
Summary -- 214
Experiment 1 -- 214
Experiment 2 -- 216
279
-------
Experiment 3 --
Experiment 4 --
Experiments 5-7
Page
216
217
217
SECTION XIV
EVALUATION OF MISCELLANEOUS BACTERIOCIDES
218
COMPARISON OF CHLORINE DIOXIDE AND SODIUM HYPOCHLORITE
Formaldehyde and Paraformaldehyde
Hydrogen Peroxide
Ozone (0-)
SECTION XV
REFERENCES
218
219
219
220
222
SECTION XVI
GLOSSARY
224
SECTION XVII
APPENDICES
226
Tables I-XVI
228
SECTION XVIII
INDEX
273
280
-------
SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
11, Rep- "ttfo.
\ 3. Accession No.
w
4. Title
COLIFORM BACTERIA GROWTH AND CONTROL IN AERATED
STABILIZATION BASINS
S. Rti-ortD&te;
I ป, Pen
7. Author(s)
Watklns, S. H.
9. Organization
Crown Zellerbach Corporation
Environmental Services Division
Camas, Washington 98607
10. Project No.
11. Contract/Grant No.
12040 GQD
13. Type cf Report
Period Covered
15. Supplementary Notes
Environmental Protection Agency report
number, EPA-660/2-73-028, December 1973.
16. Abstract
Secondary effluent from an ammonia base sulfite mill in Lebanon, Oregon,
increased concentrations of coliforms (total coliform bacteria) in receiving
waters to more than 1000 per 100 ml, the State standard. Factors responsible
for high coliform populations were determined and a disinfection method was
developed for reducing their numbers in secondary effluent. Chlorination was
often ineffective. However, by injecting NaOH into the chlorinator*s water
supply, adequate coliform kill was achieved with approximately 5.7 ppm chlorine
and 3.3 ppm NaOH. Continuous chlorination affected a reduction in coliforms
in receiving waters to acceptable levels and the chlorinated effluent had a
low degree of toxicity to salmonid fingerlings.
17a. Descriptors
*Coliforms, *Pulp wastes, *Secondary treatment, *Disinfection, *Toxicity,
*Chlorination, Bioassay, Chemical analysis, Microorganisms, Biochemical oxygen
demand, Sulfite liquors, Salmonids
17b. Identifiers
Ammonia base, Chloramines, Prosthecate bacteria, Sanitary survey, South Santiam
River, Lebanon Oregon, Crown Zellerbach Corporation
I7c. COWRR Field & Group 05D
18. Availability
IS. Security C'ass.
(Report)
20. SecurAy C^ass.
Pages
22. 'Price
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON. O. C. 2O24O
Abstractor
S. H. Watkins
I institution Crown Zellerbach
WRS1C 102 (REV. JUNE 197 I)
U.S. GOVERNMENT PRINTING OFFICE: 1974-546314:194
------- |