EPA/600/R-94/105
August 1994
OFF-GAS ANALYSIS RESULTS AND FINE PORE
RETROFIT CASE HISTORY FOR HARTFORD, CONNECTICUT
by
R. Gary Gilbert and Russell C. Sullivan
Aeration Technologies, Inc.
N. Andover, Massachusetts 01845
Cooperative Agreement No. CR812167
Project Officer
Richard C. Brenner
Water and Hazardous Waste Treatment Research Division
Risk Reduction Engineering Laboratory
Cincinnati, Ohio 45268
RISK REDUCTION ENGINEERING LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DX SOLA I MisR
Development of the information in this report has been
funded in part by the U.S. Environmental Protection Agency under
Cooperative Agreement No. CR812167 by the American Society of
Civil Engineers. The report has been subjected to Agency peer
and administrative review and approved for publication as an EPA
document. Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
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FOREWORD
Today's rapidly developing and changing technologies and
industrial products and practices frequently carry with them the
increased generation of materials that, if improperly dealt with,
can threaten both public health and the environment. The U.S.
Environmental Protection Agency (EPA) is charged by Congress with
protecting the Nation's land, air, and water resources. Under a
mandate of national environmental laws, the Agency strives to
formulate and implement actions leading to a compatible balance
between human activities and the ability of natural systems to
support and nurture life. These laws direct EPA to perform
research to define our environmental problems, measure the
impacts, and search for solutions.
The Risk Reduction Engineering Laboratory is responsible for
planning, implementing, and managing research, development, and
demonstration programs to provide an authoritative, defensible
engineering basis in support of the policies, programs, and
regulations of EPA with respect to drinking water, wastewater,
pesticides, toxic substances, solid and hazardous wastes, and
Superfund-related activities. This publication is one of the
products of that research and provides a vital communication link
between the researcher and the user community.
As part of these activities, an EPA cooperative agreement
was awarded to the American Society of Civil Engineers (ASCE) in
1985 to evaluate the existing data base on fine pore diffused
aeration systems in both clean and process waters, conduct field
studies at a number of municipal wastewater treatment facilities
employing fine pore aeration, and prepare a comprehensive design
manual on the subject. This manual, entitled "Design Manual -
Fine Pore Aeration Systems," was completed in September 1989 and
is available through EPA's Center for Environmental Research
Information, Cincinnati, Ohio 45268 (EPA Report No. EPA/625-1-
89/023) . The field studies, carried out as contracts under the
ASCE cooperative agreement, were designed to produce reliable
information on the performance and operational requirements of
fine pore devices under process conditions. These studies
resulted in 16 separate contractor reports and provided critical
input to the design manual. This report summarizes the results
of one of the 16 field studies.
E. Timothy Oppelt, Director
Risk Reduction Engineering Laboratory
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PREFACE
In 1985, the U.S. Environmental Protection Agency funded
Cooperative Research Agreement CR812167 with the American Society
of Civil Engineers to evaluate the existing data base on fine
pore diffused aeration systems in both clean and process waters,
conduct field studies at a number of municipal wastewater
treatment facilities employing fine pore diffused aeration, and
prepare a comprehensive design manual on the subject. This
manual, entitled "Design Manual - Fine Pore Aeration Systems,"
was published in September 1989 (EPA Report No. EPA/025/1-89/023)
and is available from the EPA Center for Environmental Research
Information, Cincinnati, OH 45268.
As part of this project, contracts were awarded under the
cooperative research agreement to conduct 16 field studies to
provide technical input to the Design Manual. Each of these
field studies resulted in a contractor report. In addition to
quality assurance/quality control (QA/QC) data that may be
included in these reports, comprehensive QA/QC information is
contained in the Design Manual. A listing of these reports is
presented below. All of the reports are available from the
National Technical Information Service, 5285 Port Royal Road,
Springfield, VA 22161 (Telephone: 703-487-4650).
1. "Fine Pore Diffuser System Evaluation for the Green Bay
Metropolitan Sewerage District" (EPA/600/R-94/093) by J.J.
Marx
2. "Oxygen Transfer Efficiency Surveys at the Jones Island
Treatment Plants, 1985-1988" (EPA/600/R-94/094) by R.
Warriner
3. "Fine Pore Diffuser Fouling: The Los Angeles Studies"
(EPA/600/R-94/095) by M.K. Stenstrom and G. Masutani
4. "Oxygen Transfer Studies at the Madison Metropolitan
Sewerage District Facilities" (EPA/600/R-94/096) by W.C.
Boyle, A. Craven, W. Danley, and M. Rieth
5. "Long Term Performance Characteristics of Fine Pore Ceramic
Diffusers at Monroe, Wisconsin" (EPA/600/R-94/097) by D.T.
Redmon, L. Ewing, H. Melcer, and G.V. Ellefson
6. "Case History of Fine Pore Diffuser Retrofit at Ridgewood,
New Jersey" (EPA/600/R-94/098) by J.A. Mueller and P.D.
Saurer
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7. "Oxygen Transfer Efficiency Surveys at the South Shore
Wastewater Treatment Plant, 1985-1987" (EPA/600/R-94/099) by
R. Warriner
8. "Fine Pore Diffuser Case History for Frankenmuth, Michigan"
(EPA/600/R-94/100) by T.A. Allbaugh and S.J. Kang
9. "Off-gas Analysis Results and Fine Pore Retrofit Information
for Glastonbury, Connecticut" (EPA/600/R-94/101) by R.G.
Gilbert and R.C. Sullivan
10. "Off-Gas Analysis Results and Fine Pore Retrofit Case
History for Hartford, Connecticut" (EPA/600/R-94/105) by
R.G. Gilbert and R.C. Sullivan
11. "The Measurement and Control of Fouling in Fine Pore
Diffuser Systems" (EPA/600/R-94/102) by E.L. Barnhart and M.
Collins
12. "Fouling of Fine Pore Diffused Aerators: An Interplant
Comparison" (EPA/600/R-94/103) by C.R. Baillod and K.
Hopkins
13. "Case History Report on Milwaukee Ceramic Plate Aeration
Facilities" (EPA/600/R-94/106) by L.A. Ernest
14. "Survey and Evaluation of Porous Polyethylene Media Fine
Bubble Tube and Disk Aerators" (EPA/600/R-94/104) by D.H.
Houck
15. "Investigations into Biofouling Phenomena in Fine Pore
Aeration Devices" (EPA/600/R-94/107) by W. Jansen, J.W.
Costerton, and H. Melcer
16. "Characterization of Clean and Fouled Perforated Membrane
Diffusers" (EPA/600/R-94/108) by Ewing Engineering Co.
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ABSTRACT
In the summer of 1982, the Hartford Metropolitan District
Commission, Hartford County, Connecticut, Water Pollution Control
Facility underwent a retrofit form a spiral roll coarse bubble to
a full floor coverage fine pore aeration system. Work performed
included all new in-tank piping and diffuser equipment and the
installation of new filters on the blower air intakes. From
November 1985 through August 1987, on-site studies were performed
using off-gas analysis as part of the ASCE/EPA Fine Pore
Aeration. This report presents the results of over 340 off-gas
tests together with a case history of the retrofit to upgrade the
aeration system. Historical information, retrofit evolution and
implementation, aeration performance after the retrofit, cleaning
and maintenance experience, and comparison of performance with
pre-retrofit data are included in the report.
This report was submitted in partial fulfillment of
Cooperative Agreement No. CR812167 by the American Society of
Civil Engineers under subcontract to Aeration Technologies, Inc.
under the partial sponsorship of the U.S. Environmental
Protection Agency. The work reported herein was conducted over
the period of 1985-1987.
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TABLE OF CONTENTS
Foreword iii
Preface iv
Abstract vi
Figures ix
Tables xi
Acknowledgements xii
1.0 INTRODUCTION 1
2.0 SUMMARY 5
2.1 General 5
2.2 Off-Gas Testing Results 5
2.3 Operation and Maintenance Observations 6
2.4 Diffuser Cleaning Comments 7
2.5 Design Comments 8
2.6 Recommendations 9
3.0 HISTORICAL BACKGROUND INFORMATION 11
3.1 The Treatment Facility 11
3.2 The Activated Sludge Process 11
3.3 Original Aeration System 25
3.4 Operational Problems 29
3.5 Retrofit Objectives 30
3.6 Basis for Changing to Fine Pore Aeration 31
3.6.1 Available Technology Investigation ... 31
3.6.2 Pilot Testing 32
3.6.3 Estimated Air Usage with New Equipment . 3 3
3.6.4 Blower Turndown Evaluation 3 3
3.6.5 Electrical Power Monitoring 3 3
3.6.6 Piping System Investigation 34
3.6.7 Air Filtration Requirements 34
3.6.8 Instrumentation System Requirements ... 35
3.7 Cost-Effective Evaluation 35
4.0 FINE PORE AERATION RETROFIT DESIGN DESCRIPTION 38
4.1 Basis for Design 38
4.2 Aeration Tank Configuration 41
4.3 Operating Method 43
4.4 Fine Pore Diffuser Design 4 3
4.5 Diffuser Layout and Distribution 49
4.6 Blower Design and Operation Considerations .... 50
4.7 Airflow Measurement and Distribution 53
4.8 Dissolved Oxygen/Aeration Control Scheme 53
4.9 Contract Documents and Bid 54
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4.10 Description of Fine Pore Diffuser
Equipment Purchased 54
4.11 Inspection and Testing 55
5.0 OPERATIONAL PERFORMANCE AND EVALUATION 56
5.1 System Startup 56
5.2 Operating Conditions 57
5.3 Operational Control 58
5.4 Treatment Performance 59
5.5 Aeration Performance Evaluation 59
5.5.1 General 59
5.5.2 Oxygen Transfer Efficiency 83
5.5.3 Clean Water and Mixed Liquor
Performance Comparison 85
5.5.4 Measured Alpha 85
5.5.5 Physical Observations 85
5.5.6 Laboratory Testing 86
5.6 Effect of Cleaning on Performance 86
5.6.1 Cleaning Frequency 86
5.6.2 Cleaning Method 87
5.6.3 Air Distribution and Leak Testing .... 88
5.6.4 Post Study Period Cleaning Observations . 89
5.7 Before and After Cleaning OTE Results 90
5.8 Cost of Cleaning 92
6.0 ECONOMIC CONSIDERATIONS FOR FINE PORE AERATION 95
6.1 Power Use 95
6.2 Oxygen Transfer Efficiency Comparison 96
6.3 Increase in Actual Efficiency 97
6.4 Cost Considerations 97
7.0 RECOMMENDATIONS 99
7.1 General 99
7.2 Engineering Design 99
7.3 Equipment Design 100
7.4 Operation 101
7.5 Maintenance 101
7.6 Efficiency Considerations 101
7.7 Clogging Potential 102
7.8 Mechanical Reliability 103
7.9 Overall Advances and Disadvantages 103
8.0 REFERENCES 104
APPENDICES 105
I-A Summary of Individual Off-Gas Field Tests and
Computations for Airflow-Weight averaging 105
I—B Photo Plates of Aeration Diffusers, Cleaning, and
Off-Gas Equipment 133
I-C Overall Plant Data Sheet Based on Previous
Year of Record and Supplemental Information .... 145
I-D Dome Diffuser Characterization Tests Before
and After Cleaning (April & May 1987) 156
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2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
FIGURES
Page
Historical Plant Data - Plant Flow and B0Dr .... 17
Historical Plant Data - Average Monthly Airflow and
Blower Power 18
Historical Aeration System Performance - Average
Monthly Plant B0Dr, Airflow, and KWH Per MGD ... 19
Historical Aeration System Performance - Average
Monthly Plant Airflow and KWH/B0Dr and KWH/Airflow 20
Schematic of Secondary Treatment Process 26
Schematic of Aeration System 27
Plan Sketch with Tank Dimensions 28
Section A-A: Typical Cross Section 42
Oxygen Transfer Efficiency Characteristics .... 45
Dome Diffuser Headloss Characteristics 46
Typical Layout for Dome/Disc Diffusers 47
Stainless Steel Pipe Support Assembly 48
Plan Sketch with Number of Domes per Grid, Pass, and
Tank 51
Plan Sketch with Overall Diffuser Density per grid 52
Testing and Tank Cleaning Time Summary 61
Off-Gas Sampling Plan "A" 62
Off-Gas Sampling Plan "B" 64
Plant Performance Data 65
Plant Performance Data 66
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20
21
22
23
24
25
26
27
28
29
30
31
Plant Performance Data
Plant Performance Data
Overall Performance for Total Tank ....
Overall Performance for Total Tank ....
Overall Performance for Total Tank ....
Overall Performance for Total Tank ....
Alpha x SOTE - Pass No. 2 - Influent . . .
Apparent Alpha - Pass No. 2 - Influent . .
Alpha x SOTE - Pass No. 2 - Middle ....
Apparent Alpha - Pass No. 2 - Middle . . .
Off-Gas Test Results for April 1 and 2, 1986
Study)
Off-Gas Test Results for April 1 and 2, 1986
Study)
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TABLES
Number Page
1 Chronological Summary . 3
2 Historical Plant Data 12
3 Historical Airflow Data 14
4 Historical Aeration System Performance 15
5 Wastewater Characteristics Information for Off-Gas
Test Visits 21
6 Primary Effluent Total and Soluble Carbonaceous BOD5 22
7 Off-Gas Test Chronological Summary 60
8 Overall Aeration Performance for the Whole Tank . . 69
9 Sample Location: Pass No. 2, Influent (2-1) .... 70
10 Sample Location: Pass No. 2, Middle (2-M) 71
11 Off-Gas Test Results for April 1 and 2, 1986 (Diurnal
Study) 72
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ACKNOWLEDGEMENTS
This investigation and study would not have been possible without
facilities use authorization by the Metropolitan District Commis-
sion, Hartford, CT. Messers. Paul Gilbert, James Chase, and Richard
Ehman together with the Water Pollution Control Facility staff
provided information and support which were invaluable to the
study. Their cooperation and assistance are greatly appreciated.
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1.0 INTRODUCTION
In 1968 the consulting engineering firm of Metcalf & Eddy,
Boston, MA, was retained by the Metropolitan District Commis-
sion, Hartford County, CT, to initiate the design and to
prepare plans and specifications for the construction of a
secondary activated sludge wastewater treatment facility at
the main wastewater treatment plant at South Meadows,
Hartford, CT.
In November 1972 the new secondary activated sludge wastewater
treatment facility began operation. The plant was designed
for a hydraulic capacity of 60 MGD at average flow and 109 MGD
at peak flow. The activated sludge aeration system consisted
of six identical four-pass aeration tanks, each 80 feet wide
by 194 feet long with nominal operating liquid depth of 15.5
feet. The original aeration equipment consisted of Chicago
Pump Co. "Deflectofusers." These diffusers were coarse bubble
devices with large 3/8-inch diameter orifices on the periphery
of the diffuser. Approximately 250 of these diffusers were
installed in each aeration pass on seven drop pipe/manifold
assemblies per pass. Each of the six aeration tanks contained
four aeration passes. The diffuser assemblies were located
approximately 2.5 feet above the tank floor and 2.5 feet from
the tank side wall. A spiral-roll aeration and mixing pattern
was established by this design geometry and diffuser place-
ment. The Standard Oxygen Transfer Efficiency (SOTE) of the
"Deflectofuser" system at Hartford was estimated to be between
6 and 7 percent.
From the beginning of operation of the new secondary activated
sludge wastewater treatment facility through 1979, total plant
electrical costs increased steadily from about $300,000 per
year in 1973 to over $900,000 per year in 1979. Between 1979
and 1982 a large decrease in energy usage was realized by the
upgrading of sludge handling and treatment equipment from coil
filters to belt filter presses and initiation of a new in-
cinerator operating mode. In spite of these electrical cost
reduction improvements, the total plant electrical costs con-
tinued to rise at an alarming rate. With the prediction for
steadily increasing costs for energy due to electrical rate
increases through the 1980's and 1990's and the demand for
greater air flow to supply increasing amounts of oxygen to the
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activated sludge process, it became apparent to the MDC per-
sonnel that energy efficient aeration equipment must be con-
sidered for the treatment facility.
Beginning in 1978, MDC staff engineers undertook an in-house
investigation to evaluate the feasibility of replacing the ex-
isting coarse bubble spiral-roll aeration equipment with high
efficiency (low energy usage) aeration equipment.
This report contains a detailed presentation of the aeration
equipment upgrade project at the Hartford facility together
with the results of over 340 off-gas tests conducted during
eleven site visits from September 1985 through August 1987.
Table No. 1 contains a chronological summary of the activities
which have taken place from the initial design of secondary
wastewater treatment facilities to the completion of off gas
testing of the fine pore dome diffuser equipment in August of
1987.
The report is divided into the following major topical sec-
tions;
1. Introduction
2. Summary
3. Historical Background Information
4. Fine Pore Aeration Retrofit Design Description
5. Operational Performance and Evaluation
6. Economic Considerations for Fine Pore Aeration
7. Recommendations
This Report also contains the following four appendices:
I-A Summary of Individual Test Field Measurements and
Computations for Off Gas Analysis
I—B Photo Plates of Aeration Diffusers, Cleaning, and
Off Gas Equipment
I-C Overall Plant Data Sheet Based on Previous Year of
Record
I-D Dome Diffuser Characterization Tests Before and
After Cleaning
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Table 1
CHRONOLOGICAL SUMMARY
time
Early 1968
Nov. 1972
Early 1978
through
Nov. 1979
1980 through
Sept. 1981
Late 1981
through
Feb. 1982
March 1982
Summer 1982
Nov. 1982
Aug. 1985
through
Jan« 1986
Sept. 1985
through
Aug. 1987
Oct. 1985
May 1987
EVENT
Begin design of secondary treatment
facilities by Metcalf & Eddy.
Startup of new secondary treatment
facilities.
Hartford MDC staff undertakes research
and investigation project for Fine Pore
retrofit.
Metcalf & Eddy conducts cost-
effectiveness study for Fine Pore
retrofit,
MDC staff prepares contract documents
documents for bid of Fine Pore
retrofit.
Fine Pore retrofit project bid.
Fine Pore retrofit installation.
Fine Pore retrofit placed on line.
Metcalf & Eddy conducts air blower
replacement evaluation.
ASCE/EPA Oxygen Transfer Study undertaken
undertaken in Aeration Tank No. 2
(342 off-gas tests conducted).
Aeration Tank No. 2 diffusers cleaned for
the first time.
Aeration Tank No. 2 diffusers cleaned for
the second time.
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The Summary, which follows this section, contains the signifi-
cant overview results, observations, conclusions, and recom-
mendations based on the detailed findings and evaluations
presented in the main body of the report.
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2.0 SUMMARY
2.1 GENERAL
The replacement of coarse bubble spiral-roll aeration equip-
ment with full floor coverage fine pore dome diffuser aeration
equipment at the Hartford Water Pollution Control Plant has
proven to be cost-effective. Mixed liquor oxygen transfer ef-
ficiency more than doubled, and blower power consumption was
reduced by over 40 percent of the previous baseline usage.
Annual electrical cost savings resulted in a project payback
of less than three years.
A chronological presentation of plant and aeration system per-
formance is summarized in Table No. 4. Average monthly data
is presented for airflow and blower power consumption versus
plant flow and BOD removed. Table No. 5 contains wastewater
characteristics and plant operations data for the off-gas site
visits, and Table No. 8 contains a summary of whole tank
average off-gas performance results for seven site visit tests
conducted over a two-year period.
Figure Nos. 5, 7, 8, 11,12, and 13 contain information on the
secondary treatment process and fine pore diffuser system
details. Clean water and mixed liquor oxygen transfer ef-
ficiency data for both the fine pore and existing coarse
bubble systems are presented on Figure No. 9 . Whole tank
average off-gas performance results are presented chronologi-
cally on Figure Nos. 22, 23 , 24, and 25 .
2.2 0F7-GAS TESTING RESULTS
The results of the field off-gas measurements were consistent
with the wastewater characteristics and process parameters—
there was a great degree of variability in all data. Off-gas
oxygen transfer efficiency varied widely from site visit to
site visit, test to test, and from sample point to sample
point. Replicate off-gas results of one sample location
generally varied by a small amount. Wastewater flow rate and
organic loading varied significantly during site visits and
from visit to visit. Process parameters such as MLSS con-
centration, diffuser airflow, and mean cell residence time
also varied widely throughout the study.
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Because of the wide variability in off-gas results, wastewater
characteristics, and process parameters, it was not possible
to establish clear trends between oxygen transfer performance
and operating modes, or the effect of cleaning diffusers on
oxygen transfer performance.
There was no definite trend in oxygen transfer performance
results to indicate that diffuser cleaning was effective, or
that oxygen transfer efficiency degraded over time. Possible
reasons for these results could be:
1. variations in the primary effluent quality and
process operation,
2. rapid slime buildup on diffusers shortly after
cleaning (possibly due to the high concentration of
soluble BOD in the primary effluent),
3. coarse bubbling of diffusers due to gasket and dome
bolt leaks, especially at high diffuser airflow
rates, and
4. general wide variability in off-gas results from
test to test.
The average whole tank oxygen transfer efficiency (alphaxSOTE)
for all tests was 10.0 percent and ranged from 8.2 to 12.6
percent on a site visit by site visit basis. In comparison,
average diurnal oxygen transfer efficiency tests for one
twenty-four hour period averaged 8.3 percent with a range of
6.4 to 11.3 percent over the test period.
The average whole tank apparent alpha for all tests by site
visit was 0.37 and ranged from 0.29 to 0.45. The average
diurnal apparent alpha was 0.30 and ranged from 0.23 to 0.41.
Apparent alpha* values ranged from under 0.2 to as high as 0.6
throughout the aeration tank, with the lower values usually
representative of inlet sampling locations at the head end of
the aeration passes.
2.3 OPERATION AMD MAINTENANCE OBSERVATIONS
Operation and maintenance practices for the new fine pore
aeration system differed very little from those practices used
~Includes impact or wastewater characteristics and diffuser
characteristic and any factor on transfer performance due to
fouling.
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when the coarse bubble spiral-roll system was in operation.
Automatic control of air supply by dissolved oxygen monitoring
was attempted as the fine pore aeration system came on-line,
but automatic control of air supply was not successful.
Manual air supply control with twice daily adjustment was in-
itiated soon after start-up of the new system.
Dissolved oxygen monitoring is primarily limited to the fourth
pass of the aeration tanks with no finite value of dissolved
oxygen used as a set point upon which to adjust air supply.
Mixed liquor suspended solids concentration (MLSS) varies over
a wide range and is usually higher in concentration than
desirable for optimum process operation and control. As MLSS
concentrations change so do food to biomass (F/M) ratios and
mean cell residence times (MCRT). These parameters have a
significant impact on oxygen demand per unit of BOD removed
and the transfer of oxygen to the mixed liquor.
There is no routine inspection and cleaning schedule for the
aeration equipment. Maintenance consists of repair to equip-
ment based on visual observation of any air distribution
problems at the liquid surface. Significant air leaks are
noted and repaired as soon as a tank can be scheduled for
shutdown.
2.4 DIFFOSER CLEANING COMMENTS
Cleaning of the diffuser equipment with hosing and acid ap-
plication after three years of continuous, uninterrupted
operation was beneficial. Although no clear improvement in
oxygen transfer efficiency could be noted, diffuser headloss
(dynamic wet pressure (DWP)) improved, and air leaks at gas-
kets and bolts were repaired.
Significant deposits of biological slime as well as inorganic
materials covered the dome diffusers. Inorganic deposits were
dispersed in patches on the top surface of the domes and along
the vertical sides of the domes. Slime deposits generally
were uniform over the dome surface. Wastewater inlet points
at the head end of each pass contained grit and other solids
on the tank floor to a depth of over one foot. Some dome dif-
fusers were nearly buried in these deposits.
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After three years of operation the dome and dome bolt gaskets
originally supplied with the fine pore aeration system were
badly cracked, causing air leaks at numerous points throughout
the aeration system. The dome bolts, constructed of plastic,
were loose in several places and many had failed, allowing air
to exit in large quantities from the broken dome bolt.
A few of the stainless steel gear clamp-type pipe supports
which attach the 4-inch grid piping to the pipe support and
anchor had failed, allowing the grid pipe to bow up by as much
as 2 to 3 inches. This condition caused greater air release
at the high points, and over stressing of the adjacent sup-
ports.
Air leaks were repaired by rotating the dome and gasket on the
saddle and retightening the dome bolt. If this did not work,
new gaskets were installed. Several dome bolts were broken
during this operation because of the tendency to overtighten
the dome bolt to stop the air leak. With the plastic dome
bolts, only 25 inch-pounds of torque are allowed on the dome
bolt. This very small torque level is not sufficiently large
to compress the old gaskets to seal tightly. Greater tighten-
ing of the dome bolt caused bolt failure. Failure did not al-
ways occur immediately. In some cases several days elapsed
before the bolt failed—and after the aeration tank was placed
back in service.
2.5 DESIGN COMMENTS
A preliminary evaluation of retrofit feasibility was completed
and included qualitative pilot studies to determine the rela-
tive oxygen transfer efficiency differences between the exist-
ing and potential new equipment.
The engineer's cost-effectiveness study included good design
detail for the proposed new equipment. No pilot work was done
to establish actual values for alpha, and as a result, very
high values were selected based on manufacturer experience and
other information available at that time (1980). The result-
ing airflow requirements estimated by the engineer were on the
low side (based on an alpha x SOTE of about 17.5 percent and
an alpha value of 0.75). The engineer's estimated project
cost was two to three times the actual cost, so the low
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cost offset the over estimated oxygen transfer performance
(greater power savings), and the payback period for the
project was reasonably close to the estimated payback period.
2.6 RECOMMENDATIONS
Evaluation of field oxygen transfer performance by off-gas
testing is viable and useful. In systems where significant
variations in plant loading and process operating modes occur,
a greater number of off-gas tests, over a longer time base,
provide more accurate average performance information than the
results from specific sample point and/or point-in-time test-
ing.
Fine pore retrofit or new applications' design should be based
on accurate full scale Standard Oxygen Transfer Efficiency
(SOTE) data, and realistic alpha factor values covering the
range of process conditions, tank spatial location, and was-
tewater characteristic parameters. Where possible, pilot
and/or full scale alpha testing should be undertaken, espe-
cially if unique conditions exist (i.e. industrial waste, spe-
cial process streams, or other factors which could influence
the alpha factor value). Pilot tests should use fouled as
well as clean diffusers.
In the absence of alpha factor values based on specific test-
ing, a design average range of 0.3 to 0.4 should be used for
full floor coverage dome/disc fine pore aeration. The full
range of alpha values could be from less than 0.2 to over 0.6,
depending on the several factors which must be considered when
designing the new system.
Mixed liquor alpha x SOTE values of 9 to 10 percent should be
considered for fine pore dome/disc full floor coverage aera-
tion systems operating at 15 feet of liquid depth (14-feet of
diffuser submergence) in the conventional step-feed activated
sludge process treating domestic wastewater.
Consideration should be given for the design of full floor
coverage coarse bubble diffuser equipment at inlet feed
points where alpha values could be as low as 0.2 for fine pore
diffusers and where heavy slime buildup is expected to occur.
The coarse bubble diffuser system at the inlet would provide
maintenance-free service and a greater degree of mixing and
dispersion of the influent stream.
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In diffuser systems using dome hold-down bolts, plastic bolts
should not be used. If metal bolts are used, gasket materials
should be made of the longest lasting materials available.
Currently-available gasket materials may last less than 3
years before requiring replacement to prevent air leakage
around the dome diffuser.
Grit removal or prevention should be evaluated for each treat-
ment facility. Significant grit carry-over from preliminary
and primary treatment could require costly and inconvenient
removal after system start-up. Grit removal from around and
under a fixed plastic pipe aeration grid is a slow and dif-
ficult operation.
Dissolved oxygen monitoring and airflow control instrumenta-
tion should only be as sophisticated as necessary. The
simpler the control system, the better the results.
Air supply equipment should match the aeration system. The
airflow range and system pressure requirements of the aeration
equipment must integrate with the blower equipment performance
characteristics if aeration efficiency is to be optimized. In
cases where retrofit of the aeration equipment requires sub-
stantial reduction in air supply, blower turndown
capabilities, shutdown of incremental units, or replacement of
old equipment with new, smaller equipment must be considered
and evaluated for maximum power reduction potential.
Dissolved oxygen monitoring instrumentation should be checked
and calibrated frequently, if the measurements are to be mean-
ingful .
Fine pore aeration equipment should be tested for oxygen
transfer efficiency and back pressure on a routine basis. The
results of this testing should be used to compare equipment
performance with expected values of performance, and to estab-
lish maintenance schedules for cleaning of the equipment.
Air leaks should be repaired as soon as possible to limit
intrusion of mixed liquor into the air piping system, thereby
reducing the potential for air-side fouling, to minimize
deterioration of the aeration system, and to ensure that
oxygen transfer efficiency is not reduced unnecessarily.
10
-------
3.0 HISTORICAL BACKGROUND INFORMATION
3.1 THE TREATMENT FACILITY
The Hartford Water Pollution Control Plant treats wastewater
from six greater Hartford area towns. The secondary activated
sludge treatment facility, designed in 1968 and completed in
late 1972, processes an average daily flow of about 45 MGD.
The secondary facilities are designed for an average daily
flow of 60 MGD and a peak hydraulic flow of 109 MGD.
The pollution control plant contains preliminary, primary,
secondary activated sludge, and waste sludge treatment and in-
cineration. Sludges from this plant and three other smaller
water pollution control plants are pumped to dissolved air
flotation thickeners and then blended with primary sludge.
The combined sludge mix is then pumped to belt filter presses
for dewatering prior to incineration in two of the three mul-
tiple hearth incinerators located at the site.
3.2 THE ACTIVATED SLODGE PROCESS
The activated sludge process is designed to treat a 60 MGD
average daily flow. However, over the past several years the
average daily flow has been about 45 MGD and has not increased
due to the lack of increased growth in the service area as
projected at the time of the original plant design in 1968.
Historical data for plant flow, loading, airflow, and process
conditions are contained in Tables 2 to 4 and Figures 1 to 4.
Wastewater characteristic information for the days in which
off gas testing was conducted is contained in Tables 5 and 6.
The flow from primary treatment is pumped to the secondary
facilities and split among four of the six aeration tanks
(Aeration Tank Nos. 5 and 6 have never been in operation).
Each aeration tank is 194 feet long and 80 feet wide with a
nominal liquid depth of 15.5 feet. Each aeration tank is
divided into four passes of equal size. The normal mode of
operation is step-feed. Return activated sludge (RAS) is fed
into the head end of Pass No. 1 of each aeration tank, and
primary effluent (PE) is normally split equally among Pass
11
-------
Table 2
HISTORICAL PLANT DATA
PLANT BODr, TOTAL BLOWER PLANT
MONTH & FLOW, AIRFLOW, POWER, POWER,
YEAR MGD lbs/day SCFM KWH/day KWH/day
05-82
42.70
N/A
51
813
34
750
54
328
06-82
53.60
N/A
45
403
30
776
54
328
07-82
47.07
N/A
49
944
32
717
54
328
08-82
41.57
N/A
40
042
28
112
51
200
09-82
46.69
N/A
37
979
27
767
49
117
10-82
45.92
N/A
45
035
33
047
53
569
11-82*
44.74
N/A
25
319
21
625
47
214
12-82
41.96
N/A
27
910
22
875
49
189
01-83
44.32
43
,986
27
438
22
000
50
577
02-83
54.29
37
, 128
23
771
19
375
46
712
03-83
59.11
29
,086
22
215
18
600
45
776
04-83
61.08
20
,886
17
986
15
625
41
904
05-83
54.69
22
, 350
15
792
14
375
37
938
06-83
54.63
20
,503
18
201
16
000
38
239
07-83
37.89
32
,864
20
493
17
375
40
472
08-83
37.62
37
,650
24
500
19
375
41
943
09-83
38.33
36
,762
28
521
22
000
44
180
10-83
35.35
28
,597
20
924
17
375
39
886
11-83
35.78
31
,333
23
076
18
700
41
543
12-83
41.98
21
,007
18
708
16
000
42
754
01-84
39.10
29
, 022
22
111
17
875
42
800
02-84
45.23
19
,993
24
458
16
300
41
508
03-84
54.70
20
,985
16
708
14
500
41
257
04-84
59.42
22
,796
16
472
14
625
40
800
05-84
56.06
28
,520
20
792
17
300
42
560
06-84
50.27
26
,832
19
736
16
750
42
4 57
07-84
49.86
35
,346
21
076
17
375
40
971
08-84
47.95
34
,792
21
715
18
400
42
057
09-84
46. 14
56
,952
28
576
22
250
43
943
10-84
45.52
46
,316
29
028
22
400
44
708
11-84
45.15
37
, 655
28
597
22
250
44
971
12-84
49.29
32
,886
27
097
21
433
46
686
01-85
48.47
49
,721
27
299
21
100
40
091
02-85
49.89
37
,864
26
389
21
250
46
743
03-85
45. 60
37
, 270
32
083
23
875
49
886
04-85
42.84
33
,228
33
729
25
500
51
657
05-85
46.09
35
,748
29
882
23
000
48
320
06-85
44.42
36
,676
35
590
26
500
52
171
07-85
45.46
29
,952
31
875
24
800
48
960
*Fine Pore On Line
-------
Table 2 (Continued^
HISTORICAL PLANT DATA
PLANT BODr, TOTAL BLOWER PLANT
MONTH & FLOW, AIRFLOW, POWER, POWER,
YEAR MGD lbs/day SCFM KWH/day KWH/day
08-85
50.39
26
476
23
771
18
375
44
972
09-85
47.15
30
672
27
514
20
750
44
972
10-85*
46.94
34
450
31
410
23
300
47
543
11-85
50.72
20
304
23
840
18
750
43
771
12-85
52.74
26
391
26
715
20
525
47
892
01-86
48.73
25
604
31
938
24
200
52
903
02-86
53.48
20
517
24
868
19
500
49
600
03-86
53.72
20
609
25
451
19
750
47
486
04-86
53.55
33
942
28
361
21
600
48
183
05-86
50.61
39
676
31
396
23
875
49
286
06-86
51-15
43
939
33
132
24
250
52
543
07-86
51.52
43
827
38
368
27
700
53
028
08-86
48.94
39
183
33
986
24
125
48
286
09-86
46.19
50
079
38
319
28
250
52
972
10-86
42.44
41
766
35
847
26
400
52
067
11-86
49.24
25
872
29
701
22
500
49
656
12-86
58.41
27
767
24
049
18
875
47
611
01-87
58.26
31
097
31
285
19
638
49
737
02-87
55.09
31
243
30
813
23
125
52
971
03-87
59.53
33
264
30
132
22
375
51
429
04-87
58.42
22
412
26
083
20
500
47
179
05-87**
54.87
27
457
28
063
21
500
47
716
06-87
47.83
33
109
33
229
24
375
52
558
07-87
43.02
37
673
37
778
28
300
56
241
08-87
39.37
36
446
37
021
27
250
55
059
09-87
44.41
38
519
36
368
26
500
53
974
10-87
43.46
40
595
37
500
27
625
54
049
11-87
43.39
38
720
41
319
30
125
58
928
12-87
44.98
41
265
36
535
27
250
58
907
01-88
46.65
40
851
32
590
24
403
58
457
02-88
55.64
38
051
28
521
22
000
55
436
03-88
59.80
48
876
31
910
24
100
56
338
04-88
53.29
40
888
36
639
25
750
53
779
05-88
54.66
35
102
30
694
23
125
51
246
06-88
49.83
40
727
36
139
26
400
52
777
07-88
52.64
49
609
50
722
30
875
60
261
08-88
49.35
40
746
34
819
25
875
54
257
09-88
41.14
38
428
44
507
28
800
57
837
~First Cleaning
**Second Cleaning
13
-------
Table 3
HISTORICAL AIRFLOW DATA
TOTAL AERATION TANK CHANNEL
AIRFLOW RATE AIRFLOW RATE AIRFLOW RATE
YEAR MONTH (lOOOxCFM) (lOOOxCFM) (lOOOxCFM)
83 AUG 24.8 21.6 3.2
SEP 29.0 24.2 4.8
OCT 21.0 19.3 1.7
NOV 23.3 20.7 2.6
DEC 19.0 18.1 1.0
84 JAN 21.8 19.8 2.0
FEB 19.7 18.5 1.2
MAR 16.7 16.7 0.1
APR 16.6 16.6 0.0
MAY 21.3 19.5 1.8
JUN 19.3 18.2 1.1
JUL 21.1 19.3 1.8
AUG 22.3 20.1 2.2
SEP 28.5 23.9 4.6
OCT 29.1 24.3 4.8
NOV 28.5 23.9 4.6
DEC 27.1 23.0 4.1
85 JAN 27.3 23.1 4.1
FEB 26.4 22.6 3.8
MAR 32.1 26.1 6.0
APR 33.8 27.1 6.6
MAY 29.9 24.7 5.1
JUN 35.6 28.3 7.3
JUL 31.9 26.0 5.9
AUG 23.8 21.0 2.8
AVERAGE 25.2 21.9 3.3
14
-------
Table 4
HISTORICAL AERATION SYSTEM PERFORMANCE
MONTH
BODr/
AIR-
AIR-
KWH/
AIR-
&
FLOW/
FLOW/
KWH/
KWH/
AIR-
FLOW/
YEAR
MGD
MGD
BODr
MGD
BODr
FLOW
KWH
05-82
N/A
1213.42
N/A
813.82
N/A
0.67
1.49
06-82
N/A
847.07
N/A
574.18
N/A
0.68
1.48
07-82
N/A
1061.06
N/A
695.07
N/A
0.66
1.53
08-82
N/A
963.24
N/A
676.26
N/A
0.70
1.42
09-82
N/A
813.43
N/A
594.71
N/A
0.73
1.37
10-82
N/A
980.73
N/A
719.66
N/A
0.73
1. 36
11-82*
N/A
565.91
N/A
483.35
N/A
0.85
1.17
12-82
N/A
665.16
N/A
545.16
N/A
0.82
1.22
01-83
99.25
619.09
0.62
496.39
0.50
0.80
1.25
02-83
68.39
437.85
0.64
356.88
0.52
0.82
1.23
03-83
49.21
375.82
0.76
314.67
0.64
0.84
1.19
04-83
34.19
294.47
0. 86
255.81
0.75
0.87
1.15
05-83
40.87
288.75
0.71
262.85
0.64
0.91
1.10
06-83
37.53
333.17
0.89
292.88
0.78
0.88
1.14
07-83
86.74
540.86
0.62
458.56
0.53
0.85
1.18
08-83
100.08
651.25
0. 65
515.02
0.51
0.79
1.26
09-83
95.91
744.09
0.78
573.96
0.60
0.77
1. 30
10-83
80.90
591.91
0.73
491.51
0.61
0.83
1.20
11-83
87.57
644.94
0.74
522.64
0.60
0.81
1.23
12-83
50.04
445.64
0.89
381.13
0.76
0.86
1.17
01-84
74.23
565.50
0.76
457.16
0.62
0.81
1.24
02-84
44.20
540.75
1.22
360.38
0.82
0.67
1. 50
03-84
38.36
305.45
0.80
265.08
0.69
0.87
1.15
04-84
38.36
277.21
0.72
246.13
0.64
0.89
1.13
05-84
50.87
370.89
0.73
308.60
0.61
0.83
1.20
06-84
53.38
392.60
0.74
333.20
0.62
0.85
1.18
07-84
70.89
422.70
0.60
348.48
0.49
0.82
1.21
08-84
72.56
452.87
0.62
383.73
0.53
0.85
1.18
09-84
123.43
619.33
0.50
482.23
0.39
0.78
1. 28
10-84
101.75
637.70
0.63
492.09
0.48
0.77
1.30
11-84
83 .40
633.38
0.76
492.80
0.59
0.78
1.29
12-84
66.72
549.75
0.82
434.83
0.65
0.79
1.26
01-85
102.58
563.21
0.55
435.32
0.42
0.77
1.29
02-85
75.89
528.94
0.70
425.94
0.56
0.81
1.24
03-85
81.73
703.57
0.86
523.57
0.64
0.74
1. 34
04-85
77.56
787.32
1.02
595.24
0.77
0.76
1. 32
05-85
77.56
648.34
0.84
499.02
0.64
0.77
1.30
06-85
82.56
801.22
0.97
596.58
0.72
0.74
1. 34
07-85
65.89
701.17
1.06
545.53
0.83
0.78
1.29
*Fine Pore On Line
-------
Table 4 (Continued)
HISTORICAL AERATION SYSTEM PERFORMANCE
MONTH BODr/ AIR- AIR- KWH/ AIR-
& FLOW/ FLOW/ KWH/ KWH/ AIR- FLOW/
YEAR MGD MGD BODr MGD BODr FLOW KWH
08-85 52.54
09-85 65.05
10-85* 73.40
11-85 40.03
12-85 50.04
01-86 52.54
02-86 38.36
03-86 38.36
04-86 63.38
05-86 78.40
06-86 85.90
07-86 85.07
08-86 80.06
09-86 108.42
10-86 98.41
11-86 52.54
12-86 47.54
01-87 53.38
02-87 56.71
03-87 55.88
04-87 38.36
05-87** 50.04
06-87 69.22
07-87 87.57
08-87 92.57
09-87 86.74
10-87 93.41
11-87 89.24
12-87 91.74
01-88 87.57
02-88 68.39
03-88 81.73
04-88 76.73
05-88 64.22
06-88 81.73
07-88 94.24
08-88 82.57
09-88 93.41
471.74 0.90
583.54 0.90
669.15 0.91
470.03 1.17
506.54 1.01
655.41 1.25
465.00 1.21
473.77 1.23
529.62 0.84
620.35 0.79
647.74 0.75
744.72 0.88
694.44 0.87
829.60 0.77
844.65 0.86
603.19 1.15
411.73 0.87
536.99 1.01
559.32 0.99
506.16 0.91
446.47 1.16
511.45 1.02
694.73 1.00
878.15 1.00
940.34 1.02
818.91 0.94
862.86 0.92
952.27 1.07
812.25 0.89
698.61 0.80
512.60 0.75
533.61 0.65
687.54 0.90
561.54 0.87
725.25 0.89
963.56 1.02
705.55 0.85
1081.84 1.16
364.66 0.69
440.08 0.68
496.38 0.68
369.68 0.92
389.17 0.78
496.61 0.95
364.62 0.95
367.65 0.96
403.36 0.64
471.74 0.60
474.10 0.55
537.66 0.63
492.95 0.62
611.60 0.56
622.05 0.63
456.95 0.87
323.15 0.68
337.08 0.63
419.77 0.74
375.86 0.67
350.91 0.91
391.84 0.78
509.62 0.74
657.83 0.75
692.15 0.75
596.71 0.69
635.64 0.68
694.28 0.78
605.82 0.66
523.11 0.60
395.40 0.58
403.01 0.49
483.21 0.63
423.07 0.66
529.80 0.65
586.53 0.62
524.32 0.64
700.05 0.75
0.77 1.29
0.75 1.33
0.74 1.35
0.79 1.27
0.77 1.30
0.76 1.32
0.78 1.28
0.78 1.29
0.76 1.31
0.76 1.32
0.73 1.37
0.72 1.39
0.71 1.41
0.74 1.36
0.74 1.36
0.76 1.32
0.78 1.27
0.63 1.59
0.75 1.33
0.74 1.35
0.79 1.27
0.77 1.31
0.73 1.36
0.75 1.33
0.74 1.36
0.73 1.37
0.74 1.36
0.73 1.37
0.75 1.34
0.75 1.34
0.77 1.30
0.76 1.32
0.70 1.42
0.75 1.33
0.73 1.37
0.61 1.64
0.74 1.35
0.65 1.55
*First Cleaning
**Second Cleaning
16
-------
FIGURE NO. 1
HISTORICAL PLANT DATA
AVERAGE MONTHLY PLANT FLOW AND BODr
on Line
-------
FIGURE NO. 2
HISTORICAL PLANT DATA
AVERAGE MONTHLY AIRFLOW AND BLOWER POWER
55
a:
u
5
O
Q.
K
LJ
$
o
_J
CO
<8.
§
0
_J
lL
9:
<
>- '
_)
1
I-
z
o
2
LJ
o
<
o:
LJ
5
in
~u
c
o
in
3
O
x:
50 -
45 -
40 -
35 --
30 -
25 -
20 -
15 -
10
Blower Power, KHW/day
l|l I | I I I 1 I I I I II I [
1982 1983
I
Fine Pore
on Line
I I I I I I I I I I I
1984
II I II I II I I I
( II I I I II ! I I I (
1985 I ' 1986
1st Cleaning
TIME, MONTHS
II III I I I I I I | I I I I I I I
1987 1988
I
2nd Cleaning
-------
FIGURE NO. 3
HISTORICAL AERATION SYSTEM PERFORMANCE
AVERAGE MONTHLY PLANT BODr, AIRFLOW, AND KWH PER MGD
Q
O
£
OS
u
Qu
a
z
<
s
o
J
Du
< "O
* o
(i)
M D
S 0
a f
s
Eh
Z
o
£
W
O
S
u
>
<
1982
I
1983
I | I I I I II I I I I I | II I I I I I I I I I | I I I I I I II I
1984 1985 1 1986
1st Cleaning
Fine Pore
on Line
TIME, MONTHS
I | II !l| I I II I I I | II II I II
1987 1988
I
2nd Cleaning
-------
FIGURE NO. 4
HISTORICAL AERATION SYSTEM PERFORMANCE
AVERAGE MONTHLY PLANT AIRFLOW AND KWH/BODr AND KWH/AIRFLOW
to
o
S
o
~J
h
a
H
<
\
DC
S
u:
a
z
<
u
a
o
CQ
\
*
o
j
b
Otf
Eh
Z
5
6
X
J
OC
Eh
Z
o
s
u
u
u
>
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I I I I ll I I I II I I I I I II I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I ll II I I I I 11 I I I I I I I
1982 1983 1984 1985 .1986 1987 1988
I 1st Cleaning |
Fine Pore TIME, MONTHS 2nd Cleaning
on Line
-------
Table 5
WASTEWATER CHARACTERISTIC INFORMATION FOR OFF-GAS TEST VISITS
BOD5
BODS
BOD5
TSS
PLANT
PERCENT
WASTE
WASTE
WASTE
PR1. INF.,
PRI. EFF.,
FINAL EFF.,
FINAL EFF.,
FLOW,
MLSS,
MVLSS,
RECYCLE,
SLUDGE,
SLUDGE,
SLUDGE,
F/M
(1)
DATE
mg/1
mg/1
rag/1
mg/1
MGD
mg/1
mg/1
%
lbs.xlOOO
mg/1
% VOL.
RATIO
MCRT
09-14-85
122
81
4
7
47.70
42
51.93
5666
—
—
—
10-21-85
97
44
5
18
45.40
2953
2313
53
44.36
4920
—
0.13
4.0
11-12-85
66
68
4
10
48.60
2378
1797
53
25.75
3598
75.5
0.20
7.3
11-13-85
76
52
6
18
49.05
2872
2140
47
32.93
4544
73.5
0.22
5.2
11-14-85
90
55
6
13
55.20
2950
2201
49
31.32
4434
72.2
0.19
5.9
12-19-85
217
53
7
11
52.30
2222
1713
47
36.82
4054
77.0
0.18
6.6
12-20-85
121
42
12
25
51.90
49
29.70
3434
77.1
03-24-86
50
73
10
11
53.36
3459
2608
38
36.32
5598
73.9
0.17
7.6
03-25-86
56
42
20
12
53.82
3660
2788
31
41.99
6678
75.4
0.09
7.1
04-01-86
176
67
7
10
56.67
3000
2323
35
40.63
5970
76.9
0.18
6.1
04-02-86
109
58
6
8
58.60
3759
2881
34
39.15
5724
76.5
0.13
7.9
07-14-86
152
105
10
17
54.37
5032
3748
42
48.54
7648
75.2
0.16
7.6
07-15-86
153
146
9
14
52.53
4850
3607
45
43.44
6880
75.1
0.22
8.4
02-04-87
102
66
7
16
59.89
4086
2899
39
38.35
6636
71.1
0.14
7.8
02-05-87
137
60
8
16
56.35
3732
2646
37
49.02
7320
70.9
0.13
5.7
04-22-87
60
47
4
7
62.58
3214
2367
34
34.04
5830
73.0
0.13
8.3
04-23-87
81
51
4
7
62.07
3124
2312
34
32.88
5840
73.2
0.14
7.5
06-18-87
181
122
9
12
47.15
4465
3498
44
34.18
5872
78.0
0.18
9.7
08-13-87
164
119
5
11
39.75
5812
4477
40
49.50
10712
77.1
0.11
8.2
(^MCRT Computed as follows:
/Volume of Aeration\ x /MLVSSA x fVolume of Clarifiers\ x /4th Pass MLVSS,"\
\ Tanks, mil.gal. ) [ mg/1 J \& Channels, mil.gal.I * \ mg/1 J
MCRT = = DAYS
^Return Sludge) x fWaste,\ x fFinal Effluent) x ^Plant Flow,]
\ MLVSS, mg/1 j \ MGD J \ VSS, mg/1 ) \ MGD
-------
Table 6
PRIMARY EFFLUENT TOTAL AND SOLUBLE CARBONACEOUS BOD5
TOTAL BOD5, SOLUBLE BODg, PERCENT SOLUBLE,
DATE mg/1 mg/1 %
11-21-85
11-25-85
11-26-85
12-02-85
12-03-85
12-04-85
12-05-85
12-12-85
12-18-85
12-23-85
12-31-85
44
53
40
48
95
40
60
53
44
110
111
17
20
14
17
17
18
14
19
19
78
44
38.6
37.7
35.0
35.4
17.9
45.0
23.3
35.8
43.2
70.9
39.6
01-07-86
01-14-86
01-21-86
01-26-86
01-28-86
02-04-86
02-19-86
02-26-86
03-03-86
03-10-86
03-18-86
03-25-86
04-01-86
04-09-86
04-15-86
04-22-86
04-28-86
05-05-86
05-12-86
05-19-86
06-04-86
06-10-86
06-17-86
06-24-86
06-30-86
07-08-86
07-14-86
07-21-86
90
90
109
63
65
55
67
81
100
79
75
42
67
113
65
62
115
98
117
101
157
97
119
80
94
103
105
105
53
44
6
26
25
17
24
37
60
31
14
18
20
30
24
26
112
28
33
48
92
24
32
12
39
54
20
39
58.9
48.9
5.5
41.3
38.5
30.9
35.8
45.7
60.0
39.2
18.7
42.9
29.9
26.5
36.9
41.9
97.4
28.6
28.2
47.5
58.6
24.7
26.9
15.0
41.5
52.4
19.0
37.1
22
-------
Table 6 (Cont.)
PRIMARY EFFLUENT TOTAL AND SOLUBLE CARBONACEOUS BOD5
TOTAL BOD5, SOLUBLE BOD5, PERCENT SOLUBLE,
DATE mg/1 rag/1 %
08-04-86
08-12-86
08-18-86
08-26-86
09-02-86
09-05-86
09-15-86
09-22-86
10-06-86
10-14-86
10-22-86
10-27-86
11-03-86
11-10-86
12-01-86
12-08-86
12-15-86
12-22-86
12-29-86
101
87
85
88
158
137
137
150
167
220
116
68
139
149
92
114
74
62
85
43
41
28
47
83
60
97
89
54
84
64
59
63
69
32
31
36
34
52
42.6
47.1
32.9
53.4
52.5
43.8
70.8
59.3
32.3
38.2
55.2
86.8
45.3
46.3
34.8
27.2
48.6
54.8
61.2
01-05-87
01-12-87
01-20-87
01-26-87
02-02-87
02-09-87
02-16-87
02-23-87
03-02-87
03-09-87
04-13-87
04-20-87
04-27-87
05-04-87
05-11-87
05-18-87
05-26-87
06-02-87
06-16-87
54
79
57
71
71
59
105
88
48
60
23
51
65
84
59
72
109
99
83
31
105
52
41
40
29
38
53
24
43
20
25
65
39
34
41
58
45
36
57.4
132.9
91.2
57.7
56.3
49.2
36.2
60. 2
50.0
71.7
87.0
49.0
100.0
46.4
57.6
56.9
53 . 2
45.5
43.4
23
-------
Table 6 fCorit.)
PRIMARY EFFLUENT TOTAL AND SOLUBLE CARBONACEOUS BOD5
TOTAL BOD5, SOLUBLE BODg, PERCENT SOLUBLE,
DATE mg/1 mg/1 %
06-22-87 95 28 29.5
06-29-87 82 56 68.3
07-06-87 137 116 84.7
07-13-87 88 60 68.2
07-20-87 150 58 38.7
07-27-87 162 49 30.2
08-03-87 111 37 33.3
08-10-87 88 30 34.1
AVG. FOR
PERIOD 81.8 40.7 49.2
11-21-85
TO
02-04-86 69 26 37.7
02-19-86
TO
12-29-86 104 46 44.2
01-05-87
TO
08-10-87 83 46 55.4
24
-------
Nos. 2, 3, and 4. Figure No. 5 contains a schematic of the
secondary treatment process. Schematics of the aeration tanks
are contained on Figure Nos. 6 and 7.
The step-feed mode of the activated sludge process proves
beneficial at Hartford. When the mixed liquor suspended
solids (MLSS) are high, the step configuration tends toward a
contact mode of operation to relieve the solids loading rate
on the final clarifiers. When the MLSS concentration is
lower, a more conventional mode is established which shifts
solids from the aeration tanks to increased clarifier loading,
and thereby improves the density of waste sludge being fed to
the thickeners.
Only four of the six 1.8 million gallon aeration tanks are
used because wastewater flows and organic loadings have not
increased as rapidly as predicted at the time the facility was
designed. The mixed liquor flows from the four aeration tanks
to six, 125-ft. diameter circular final clarifiers. The over-
flow from the final clarifiers is chlorinated between May and
September and discharged to the Connecticut River.
The settled sludge from the final clarifiers is returned to a
common wet well where 95 percent of the sludge is returned to
the aeration system at a rate equal to 25 percent of plant
flow. All return activated sludge (RAS) is fed to the head
end of pass no. 1 of each of the four aeration tanks. The
waste sludge is pumped to the dissolved air flotation thicken-
ing system for further treatment.
3.3 ORIGINAL AERATION SYSTEM
The "original equipment" aeration system installed in 1972 was
Chicago Pump Co. "Deflectofusers", which were coarse bubble
diffusers with large, 3/8-inch diameter orifices on the
periphery of the device. The diffusers were placed on
manifolds and drop pipe assemblies with seven drops per pass.
There were 252 diffusers installed in each aeration pass. The
diffusers and manifolds were placed 2.5 feet above the tank
floor and 2.5 feet from the tank wall, thus providing a spiral
roll configuration in each pass. Although this diffuser con-
figuration kept the tank floor free of equipment, facilitating
cleaning of the tank as necessary, the resulting oxygen trans-
fer efficiency was very low. It was estimated that the
25
-------
FIGURE NO. 5
SCHEMATIC OF SECONDARY TREATMENT PROCESS
nm.iiKNT
26
-------
FIGURE NO. 6
SCHEMATIC OF AERATION SYSTEM
BLOWER BUILDING
J
(note 1)
No. 1
(note 1)
No. 3
(note 2)
No. 5
Future
| Tank
L
No. 7
J
(note
1)
Test
Tank
No.
2
(note 2)
No. 6
(note
1)
No.
4
i r
~i
I Future
I Tank
w
K
W
H
b,
H
~3
U
z
H
_1
FOUR-PASS AERATION TANKS
Retrofitted with dome diffusers and in service.
Not retrofitted and not in service.
27
-------
FIGURE NO. 7
PLAN SKETCH WITH TANK DIMENSIONS
4)
V
c\
PASS
EFF
PE
I
20 ft.
typ.
s
rH
8
H
RAS
I
»
0
rH
A
t.
I
PE
t
PE
2
Nominal liquid volume per pass:
Nominal total liquid volume:
60,140 cu. ft.
449,850 gal.
240,560 cu. ft.
1,799,400 gal.
Nominal liquid Eide water depth:
15.5 ft.
28
-------
Standard Oxygen Transfer Efficiency (SOTE) of the original
diffuser equipment was between 6 and 7 percent- As long as
energy was relatively inexpensive, emphasis was placed on an
uncomplicated system that required little maintenance.
The air supply for the activated sludge process is furnished
by one of three identical Brown-Boveri rotary vane blowers.
Each blower is rated at a maximum output of 60,000 SCFM at 7.5
psig. Each blower is driven by a 3,000 HP motor. The rate
of airflow generated by the blower is adjusted by the
positioning of the inlet guide vanes on the suction side of
the blower.
The air supply control system is designed with flow control
and flow indicators for each pass of each aeration tank. A
dissolved oxygen (DO) probe senses the amount of dissolved
oxygen in the pass, then the signal is fed to an analyzer, and
then to an electronic controller where the DO is manually set.
The output signal from the controller modulates the 12-inch
motor operated butterfly valves which meter the correct amount
of air to match the set-point DO which is manually set at the
controller.
As the air supply control valve to each aeration pass is modu-
lated, the main venturi senses the change in pressure and
airflow throughout the entire system. A pressure controller
modulates the vanes in the blower to maintain constant system
pressure.
3.4 OPERATIONAL PROBLEMS
Due to an inefficient sludge dewatering operation which
prevented sludge from being wasted at a sufficient rate, the
MLSS and MCRT (mean cell residence time) were far above
design. As a result, foam in large amounts was always present
on the surface of the aeration tanks, with foam overflow to
the walkways, pipe galleries and surrounding area occurring
frequently.
Large quantities of scum were also present on the final
clarifiers, creating serious problems in the winter months.
The formation of "scumburgs" would trip the collection equip-
ment necessitating the use of a crane with clamshell to remove
the frozen scum from the clarifiers.
29
-------
The installation of new belt filter presses in 1978 and 1979
provided for more efficient processing of waste sludge,
thereby reducing MLSS, MCRT, and sludge inventories. The
lowered operating parameters provided for better process con-
trol and reduced the foam and scum problems. However, mixed
liquor DO remained very low, and oxygen demand frequently ex-
ceeded the capacity of one blower.
From startup in 1972, one blower always operated at full
capacity. Yet DO demand in the aeration system, particularly
at the inlet points, was not fulfilled during the summer
months. The only operational solution was to turn on a second
3,000 HP blower. This was a costly proposition for providing
a small amount of additional air supply.
3.5 RETROFIT OBJECTIVES
Faced with the need for additional aeration capacity (greater
oxygen transfer), steadily increasing electrical rates, and
the demand charge for placing a second 3,000 HP blower on
line, MDC staff engineers initiated an in-house retrofit
evaluation project in 1978 for the purpose of reducing future
energy usage and power costs. Since the electrical consump-
tion for the aeration system accounted for more the 60 percent
of total plant electrical usage, any substantial reduction in
energy usage for the aeration system would significantly
reduce overall plant usage, thereby reducing power costs ac-
cordingly .
In addition to the objective of significant electrical power
cost savings, other objectives included:
1. payback of capital cost of the project in ap-
proximately 3 years,
2. minimum additional operational and maintenance costs
over the existing aeration equipment,
3. operational flexibility,
4. additional aeration capacity sufficient to use only
one blower as long as possible, and
5. no reduction in process results and effluent water
quality.
30
-------
3.6 BASIS FOR CHANGING TO FINE PORE AERATION
From early 1978 to the startup of the fine pore aeration sys-
tem retrofit in November 1982, several tasks were undertaken
to determine the best technology to use, type of equipment
design to specify, and interface with the existing equipment
such as piping, blowers, and control and instrumentation.
The initial phase of investigation was undertaken by MDC
staff engineers from early 1978 through 1979. The objective
of this phase of the retrofit evaluation was to determine and
select the most efficient, cost-effective, and compatible with
the existing facilities air-diffusion equipment. The inves-
tigation was divided into the following phases:
1. Available Technology Investigation
2. Pilot Testing
3. Estimated Air Usage with New Equipment
4. Blower Turndown Evaluation
5. Electrical Power Monitoring
6. Piping System Investigation
7. Air Filtration Requirements
8. Instrumentation System Requirements
3.6.1 Available Technology Investigation
The MDC contacted manufacturers of aeration equipment, con-
sultants, and end users of fine pore retrofit systems to
gather information on the various types of high efficiency
diffuser equipment available and in use at that time. Initial
review of mechanical and jet aerators indicated that they
would not be compatible with the existing tank geometry and
other facility equipment. The investigation narrowed to dif-
fused air equipment such as ceramic domes and discs, plastic
tubes, static mixers, and other diffusers with high oxygen
transfer efficiency claims. After further review of this
group of devices, it was evident that ceramic domes and discs
seems to indicate the greatest oxygen transfer efficiency and
satisfied the compatibility requirements with tank geometry
and the air supply system. Therefore, dome/disc type dif-
fusers were chosen for pilot testing.
31
-------
3.6.2 Pilot Testing
Initial pilot tests consisted of mounting a single ceramic
dome on the bottom of a large container. A "Deflectofuser"
was also tested and used for comparison with the ceramic dome.
Tests consisted of bubbling air through the diffusers in clean
water. Observations were made of bubble size, formation, and
flow patterns.
The second pilot test phase consisted of evaluating the per-
formance of two, side-by-side, 55-gallon drums containing one
type of diffuser in each drum. Each drum was also equipped
with an air supply with airflow measurement, and a portable
DO meter. This experiment provided comparable performance un-
der identical test conditions for the fine pore dome diffuser
and the coarse bubble diffuser operating in the plant aeration
system. With the drums filled with activated sludge and
airflow held constant, the fine pore dome diffuser drum would
rapidly develop and maintain at least double the dissolved
oxygen concentration of the coarse bubble diffuser drum. When
airflows were adjusted to maintain the same DO in each drum,
the dome diffuser required only one half as much air as the
coarse bubble diffuser.
A third pilot test program was conducted with the use of a
300-gallon activated sludge pilot plant. Four ceramic dome
diffusers and one coarse bubble diffuser were mounted on iden-
tical piping systems in the bottom of the pilot plant. The
pilot plant was set up as an aeration tank with a continuous
flow-through of activated sludge from one of the four main
aeration tanks. While the 55-gallon drum tests had compared
the diffusers on a one-on-one basis under batch conditions,
the continuous flow-through pilot plant tests utilized more
realistic fine pore dome to coarse bubble diffuser ratios of
2-to-l and 4-to-l. Each diffuser system was operated alter-
nately over short periods of time until a steady dissolved
oxygen concentration was achieved. The amount of air required
by each diffuser system was measured and recorded. Several
tests were performed, and it was determined that the fine pore
dome diffuser system required only 40 to 50 percent of the air
required for the coarse bubble diffuser system when both sys-
tems operated at the same dissolved oxygen concentration. One
observation noted during this comparison testing was that the
fine pore system produced more foam than the coarse bubble
32
-------
system. However, sludge wasting was limited at that time, and
it was felt that foaming could be minimized when the new belt
filter presses were installed and operating.
3.6.3 Estimated Air Usage with New Equipment
The pilot test program indicated that there could be a 50 to
60 percent reduction in total air supply requirements for
aeration. Plant operating data indicated that approximately
8,000 SCFM of air was required to maintain solids in suspen-
sion in the influent channels with an estimated 14,000 SCFM of
air necessary for aeration in the activated sludge process.
The total estimated air supply requirements were set at 18,000
to 22,000 SCFM. With one blower normally operating at maximum
capacity of 60,000 SCFM for the existing aeration system, the
next concern was to investigate the turndown capability of the
blower equipment.
3.6.4 Blower Turndown Evaluation
With the assistance of the blower manufacturer, the turndown
characteristics of the rotary vane blowers were investigated.
Surge point, efficiency, and power consumption were studied,
and a procedure was devised to reduce the blower output while
maintaining a fixed discharge pressure. Site tests were con-
ducted, and it was determined that the blower could be turned
down to below 10,000 SCFM without surging. However, operating
efficiency did diminish as airflow was reduced.
3.6.5 Electrical Power Monitoring
It was determined that blower energy usage information would
be necessary for retrofit comparative purposes. Prior to the
investigation accurate power consumption data was not avail-
able. Watt meters were installed at the motor control center
and daily readings of KWH and total airflow were made and re-
corded. This base line data for the blower power consumption
was necessary to determine what portion of the entire plant's
electrical power consumption was for aeration.
33
-------
3.6.6 Piping System Investigation
The original air piping system at the Hartford Water Pollution
Control Plant was constructed of spiral welded steel and
wrought iron pipe. Some corrosion, rusting, and scaling of
these types of pipes usually occurs after a few years of serv-
ice, but normally, this does not cause an operating and main-
tenance problem in coarse bubble aeration equipment. In order
to be certain that the existing air pipes were rust free and
capable of being used for the fine pore diffusers, it was
necessary to field inspect the air piping system.
Air blowers were shut off during the inspection period. The
main 60-inch diameter air header and branch piping down to
24-inch diameter were inspected from within. Smaller diameter
piping was inspected by removing fittings. The suction lines
from the air filters to the blowers were also inspected.
The results of the air piping inspection revealed the follow-
ing:
1. The bituminous epoxy coating in the air mains and
suction lines were in excellent condition and would
be suitable for the fine pore system without repair.
2. The coating in the 12-inch air pipes in Aeration
Tank Nos. 1, 2, 3, and 4 was in good condition. The
coating in the same air pipes in Aeration Tank Nos.
5 and 6 (never operated) was damaged with resulting
rusting and scaling.
3. The 6-inch drop pipes and manifolds to which the
"Deflectofusers" were connected were rusted, and the
drop pipes could not be used with the fine pore
aeration system.
3.6.7 Air Filtration Requirements
The fine pore ceramic domes would require removal of 9 5 per-
cent of all particles 0.3 microns and larger in size in the
air supply. The existing automatic oil bath filters were
capable of removing only 25 to 30 percent of the particles
and; therefore, were not usable alone with the fine pore sys-
tem. Several alternate systems were evaluated including
American Air Filter Co. "Biocell" and "Electro-pak" filters.
34
-------
The "Biocell" filters, which could be installed inside the ex-
isting inlet plenums, would require only a structural frame.
There was sufficient space in the inlet plenum to permit in-
stallation of the "Biocell" filters.
The "Electro-pak" filter is an electrostatic precipitator.
Because of its expense and large size, it was not considered
feasible for this installation.
3.6.8 Instrumentation System Requirements
The air control system was designed with flow control and flow
indicators for each pass of each aeration tank. One DO probe
in each pass sensed the amount of dissolved oxygen in the
mixed liquor. A signal was fed to an analyzer and then to an
electronic controller where the desired DO concentration had
been previously set. The output signal from the controller
modulated a 12-inch motor operated butterfly valve which con-
trolled the amount of air to match the set-point DO. As each
aeration pass was modulated, the main venturi sensed the
change in pressure and flow in the entire system.
With low airflows anticipated due to the retrofit to the fine
pore system, the range efficiency of the instrumentation sys-
tem and the effects of low airflows on the DO problems were of
concern. The equipment manufacturers were contacted and given
the projected operating parameters. It was recommended that
the existing range tubes in each flow transmitter be replaced
with new range tubes so that the transmitters would be sensi-
tive to future operation with the reduced airflow. Recalibra-
tion of the transmitter would also be required. In addition,
the airflow totalizer gears and airflow indicator scales for
each flow controller would require replacement. The DO probe
manufacturer indicated that the existing probes would function
satisfactorily with the fine pore system without modification.
The small bubbles and vertical rise of the fine pore system
versus the spiral roll of the coarse bubble system were con-
sidered not to be a problem.
3.7 COST EFFECTIVE EVALUATION
In 1980 Metcalf & Eddy, the original designers of the plant,
was retained by the MDC to review the evaluation conducted by
35
-------
MDC staff engineers. Metcalf & Eddy concurred with the find-
ing of that investigation and were subsequently retained in
1981 to conduct a detailed cost-effectiveness analysis study
of the retrofit from coarse bubble to fine pore aeration. The
work by Metcalf & Eddy consisted of evaluation of the existing
coarse bubble diffuser system as well as proposed installation
of fine pore ceramic domes or disc and fine pore tube diffuser
systems. The evaluation included investigating the oxygen
transfer efficiencies of these systems, present and projected
air requirements and power usage of these systems, present and
future wastewater flows and load projections, and each
system's relative cost-effectiveness over a planning period of
20 years.
Based on the cost-effectiveness study by Metcalf & Eddy, the
following major conclusions were drawn:
1. For the future operating conditions expected at the
Hartford Water Pollution Control Plant, clean water
oxygen transfer efficiencies for the existing coarse
bubble would be 7%; the proposed fine pore tube ef-
ficiencies would be 15% and the efficiencies for the
fine pore ceramic domes would be 29%.
2. Minimum air requirements for the fine pore domes
would be dictated by the air needed for mixing to
keep the MLSS in suspension.
3. Peak air demand for proposed fine pore domes could
be supplied by one existing blower throughout the
planning period.
4. Peak air demands for the existing coarse bubble sys-
tem, as well as for the proposed fine pore tubes,
would require simultaneous operation of two blowers
during warm summer months.
5. Even with increased submergence and increased head-
losses with fine pore domes and tubes, the total
system head on the blowers would be well within the
capacity of the existing equipment.
6. Blower surging would not be expected to occur for
the expected air demand with the proposed fine pore
systems.
36
-------
7. The capital as well as operating costs of the fine
pore domes/discs would be smaller than those for the
fine pore tubes.
8. Due to higher initial capital expenditures and
higher operational costs of the fine pore tubes
(resulting from lower oxygen transfer efficiencies),
the fine pore domes would have a distinct cost ad-
vantage over the tubes.
In 1981 the estimated capital cost for all recommended im-
provements to retrofit to fine pore domes or discs was between
$1,115,000 and $1,830,000 with an estimated payback of between
3 and 6 years based upon the finding in the Metcalf & Eddy
report.
Based upon the work conducted by MDC staff personnel and the
cost-effectiveness study conducted by Metcalf & Eddy, it was
recommended to:
1. Initiate design to prepare plans and specifications
to retrofit four of the six aeration tanks to fine
pore ceramic domes.
2. Modify the existing valves and rate controllers on
air lines to each individual pass of each tank and
replace the associated range tubes in the transmit-
ters. Change the air flow rate indicator scales.
3. Install "Biocell" air filters in all three inlet
plenums of the three blowers.
The design phase (Recommendation No. 1) was initiated by the
MDC in early 1982.
37
-------
4.0 FINE PORE AERATION RETROFIT DESIGN DESCRIPTION
4.1 BASIS FOR DESIGN
The 1981 cost-effectiveness study conducted by Metcalf & Eddy
included a complete design review for sizing the fine pore
aeration system to meet the process needs through the year
2001. Existing and projected flow rates and process loadings
were estimated as follows:
Parameter
1982
2001
Plant Inflow
Average daily flow, mgd
Peak daily flow, mgd
Average daily BOD5, mg/1
lbs/day
46.4
86.0
125
48,400
60.0
120.0
136
68,100
Primary Effluent
Average daily B0Ds, mg/1
lbs/day
Peak daily BOD5, lbs/day
Ratio of peak/average B0D5
Average daily TKN, mg/1
lbs/day
78
30,200
44,200
1.46
22.2
8,600
95
46,800
72,700
1. 53
23.1
11,600
The design basis for the operating MLSS concentration was
2,000 to 2,500 mg/1, although actual MLSS concentrations in
past years rose as high as 6,000 mg/1 and averaged about 4,000
mg/1 due to sludge wasting restrictions. The projected F/M
ratio for the retrofit was 0.2 to 0.3 which resulted in a
ratio of oxygen required/BOD removed (lb. 02/lb. BOD) of about
1.0 based on design criteria in WPCF MOP No. 8.
Earlier operation at much higher MLSS concentrations and lower
F/M ratios results in oxygen required/BOD removed ratios of
38
-------
1.8 to 2.0. It was obvious that significant energy savings
could be realized by operating the process at lower MLSS con-
centrations.
Based on the above criteria the average daily oxygen require-
ments at field conditions (OTR) were projected as follows:
Average daily oxygen requirement,
lbs/day
Time
Case of Year 1982 1987 1994 2001
4 aeration May-Oct. 49,900 56,000 40,700 73,000
tanks from 1982
through 1997;
6 aeration Nov.-Apr. 30,200 34,600 40,700 46,800
tanks from 1998
through 2001
The determination of the required oxygen transfer rate at
Standard Condition (SOTR) was made for the existing aeration
equipment and two types of high efficiency fine pore diffuser
systems using the following equation and oxygen transfer
parameters:
OTR
S0TR =
^°w " Cl\
— - 1.024(T-20)
cs I
Where:
a = Relative rate of oxygen transfer in wastewater as
compared to clean water, dimensionless (equal to
0.75 for ceramic fine pore domes/discs, 0.80 for
ceramic fine pore tubes, 0.85 for existing
diffusers).
39
-------
p = Relative oxygen saturation value in wastewater as
compared to clean water, dimensionless (commonly
equal to 0.95).
Cs = Oxygen saturation value of clean water at Standard
Conditions, 9.17 mg/1.
— Oxygen saturation of water at given temperature and
altitude, 10.15 mg/1.
CL = Operating DO level, 2.0 mg/1.
T = Average temperature of mixed liquor, 15°C.
Using the above relationship, the estimated oxygen ratios of
SOTR-to-OTR for three types of diffusers were as follows:
Diffuser Type SOTR/OTR Ratio
Fine pore domes/discs 1.80
Fine pore tubes 1.69
Existing coarse bubble 1.59
The selection of alpha factors (based on the process opera-
tional modes, wastewater characteristics, and type of dif-
fusers under consideration) was not based on pilot or other
testing, but rather from existing general information and
criteria available to the consultant and from information sup-
plied by the various diffuser manufacturers.
The average oxygen transfer efficiencies at Standard Condition
(SOTE) selected by the consultant for each type of diffuser
were as follows:
Diffuser Type SOTE. Percent
Fine pore dome/disc 29
Fine pore tubes 15
Existing coarse bubble 6
The resulting airflow requirements for each type of diffuser
for the 1982 estimated oxygen transfer criteria were:
40
-------
Condition
Average Daily Air Requirement. SCFM
Coarse Bubble Tubes Domes/Discs
Without nitrification 45,900 27,100 20,500
With nitrification 68,100 36,900 26,000
The above values do not include airflow requirements for in-
fluent channel mixing. Estimated total airflow requirements
for the dome/disc diffuser aeration system plus influent chan-
nel air were as follows:
1982
Avg. Max. Min.
Air require-
ments without
channel air,
SCFM
Total air
required,
SCFM
Min.
3,900 17,900
15,900 29,900
19,200 6,100
31,200 18,100
2001
Avg. Max.
25,900 27,800
37,900 39,800
4.2 AERATION TANK CONFIGURATION
The existing four of six aeration tanks originally placed in
service in 1972 would continue to be used after the retrofit
to fine pore aeration. No modifications to the tanks or to
the process liquid piping would be necessary. Only in-tank
air piping would be changed.
Details of the aeration tank dimensions are contained on
Figure No. ?. Each of the four tanks is identical in size,
and each contains four aeration passes. The overall tank
dimensions are 194 feet long by 80 feet wide. The nominal
average operating liquid level is 15.5 feet. Each aeration
pass is approximately 20 feet wide by 194 feet long. Primary
effluent or return activated sludge enters one end of the
pass and exits the opposite end, 194 feet away.
Figure No. 8 contains a typical cross section of one aeration
pass. The walls between aeration passes are the Y-wall type,
and the bottoms of the aeration passes contain fillets to
41
-------
FIGURE NO. S
SECTION A-A: TYPICAL CROSS SECTION
C (x ¦A ' .
« • £> ' «0 -x
» ' a , fl* ' o*
N
$
*
Hi
I
iP
in
if
3
t
I'
H
< K
V.
A_
„ •¦•'* . < • /).. - 0. ' a,.- « ^
''.V:o -. •?¦¦ a • /¦• -
42
-------
prevent solids deposition and build-up at the intersection of
the wall and floor. Process air piping for each aeration pass
is contained in the Y-wall directly beneath the walkway.
4.3 OPERATING METHOD
The mode of operation both before and after retrofit to fine
pore aeration equipment is step-feed. Aeration pass no. 1 is
used for reaeration of the return activated sludge. Normally
one third of the primary effluent is fed into the head end of
the remaining three passes. Figure No. 7 shows each of the
feed points and flow pattern through the aeration tank.
Process liquid flow to each aeration pass is introduced
through a sluice gate in the center of the end wall and about
3 feet below the liquid surface. Flow from one aeration pass
to the next is through a large opening in the wall between
passes. The opening is approximately 12 feet wide by 12 feet
high. Primary effluent entering any of the three aeration
passes is mixed with the effluent from the upstream pass.
Some back mixing occurs at the ends of the aeration passes.
Flow from the aeration tank at the end of pass no. 4 is via a
U-shaped weir to effluent channels. There is approximately a
2-foot drop in the hydraulic profile at this point.
4.4 FINE PORE DIFFOSER DESIGN
The layout and design of the fine pore dome diffuser system
was planned so that most of the existing air piping could be
utilized without modification. This was an especially impor-
tant consideration since all of the air piping outside of the
aeration tanks was in good condition and usable. The new sub-
merged air distribution piping and diffuser grid piping was
designed to facilitate an easy and economical installation.
Since the full floor coverage dome/disc type of fine bubble
diffuser aeration equipment resulted in the lowest total
airflow requirements of any type system evaluated, contract
drawings and specifications were prepared for either a dome-
or disc-type ceramic diffuser aeration system. Specifications
were written to allow equipment furnished by the Norton Co.,
Worcester, MA, and by Sanitaire, Milwaukee, WI, or by a
manufacturer of equal equipment.
43
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The acceptable fine pore diffuser system had to have
guaranteed oxygen transfer efficiencies of 28 percent SOTE at
0.5 SCFM/diffuser, 26 percent SOTE at 1.0 SCFM/diffuser, and
23 percent SOTE at 2.0 SCFM/dif fuser when operated at the
average design diffuser density of 5.1 sq.ft. per diffuser in
15.5 feet of clean water. In addition, the minimum airflow
criteria of 0.5 SCFM/diffuser was established to prevent
water-side fouling. Furthermore, a minimum mixing requirement
of 0.12 SCFM/sq. ft. of tank bottom was established together
with a minimum diffuser spacing of 2 feet on center. Cer-
tified oxygen transfer and mixing test results were required
as part of the bid documents of each manufacturer submitting a
bid. (Diffuser performance data are presented on Figure Nos.
9 and 10).
The air distribution piping was specified to have built-in ad-
ditional diffuser capacity of 50 percent over the minimum num-
ber of diffusers specified. This would be accomplished by
supplying 50 percent more diffuser saddles or base plates than
the base design called for. Each air distribution pipe grid
would have the 50 percent excess diffuser capacity. The air
distribution piping would be manufactured of 4-inch UPVC
(unplasticized polyvinyl chloride) pipe and 4-inch UPVC expan-
sion tees. The grid would be installed so that the top of the
diffuser grid was level, and the top of the diffusers would be
14.5 feet below the liquid surface. The new grid piping would
be connected to the existing 12-inch air supply mains with a
new 4-inch diameter stainless steel drop pipe and manually
operated throttling valve. Each aeration pass would have
seven grids, one for each of the existing air drop pipes.
Each of the diffuser grids would contain a moisture blowoff
assembly to remove any residual moisture after the startup of
the aeration system. (Figure No. 11 contains a typical dif-
fuser grid piping layout).
The plastic piping and fittings would be supported and
anchored to the concrete floor slab using an adjustable stain-
less steel pipe support assembly which would allow for verti-
cal adjustment increments of 1/8-inch (A detail of the dif-
fuser and pipe support system supplied is presented on Figure
No. 12). Each grid pipe support would be anchored to the tank
floor with two, 1/4-inch diameter stainless steel anchor
bolts. The 4-inch UPVC pipe would be secured to the pipe sup-
port with a 4-inch stainless steel gear clamp or approved
equal attachment.
44
-------
Figure 9
OXYGEN TRANSFER EFFICIENCY CHARACTERISTICS
35
30-
25
20-
15
10
AERTEC Data ' V
Yunl Data
NORTON DOME DIFFUSER SOTE'
(based on data by Yunt and AERTEC)
'D
*Doma ditfuaar afficiaocia*
baaad on 15.5-fl. liquid dapth
and 14.5-ft air ralaaaa dapth
and an average diffuaar density
of 3.2 aq.ft par dome.
GENERIC DOME/DISC DIFFUSER SOTE
{Specified by MDC)
GENERIC DOME/DISC DIFFUSER a-SOTE
(Specified by MDC using 1980 industry value for a of 0.75)
ACTUAL NORTON DOME
DIFFUSER a SOTE
(based on off-gas testing)
///si..-
NORTON DOME DIFFUSER a SOTE*
(based on 1985 industry values lor a of 0.55)
Test month & year
ORIGINAL COARSE BUBBLE
SPIRAL ROLE EQUIPMENT
(based on data by Yunt
and the manufacturer)
a • SOTE~4.4%
• 'DEFLECTO FUSERS at 13.0-#. air
ralaaaa depth and IS.S-ft. liquid dapth.
0.0
0.4
0.8
1.2
1.6
2.0
2.4
Airflow Per Diffuser, SCFM
45
-------
FTGIJRE NO. 10
DOME DIFFUSER HEADLOSS CHARACTERISTICS
FLOW RATI (SCFM/DOME)
46
-------
FIGURE NO.11
TYPICAL LAYOUT FOR DOME/DISC DIFFUSERS
5 O-
h >
I-
a.
>
00
h h
cp a
<2 H
PASS 4
t
y-or _
a.
>
IVi
PASS 3
1
- 20'O"-
(TYP)
2'-6"
5
NO. OF DOMES/DISCS
PASS 1
PASS 2
PASS 3
PASS 4
TOTAL TANK
1064
793
793
679
3329
PASS 2
(SAME AS
PASS 3)
PASS 1
2'-3"
1
OIFFUSER
AIR HEADER
TANK FLOOR
•'» *4 ' " • ' :
° ¦« »»'
•" » v"; ' •#
• ' • . ^ ^ * ' p
DIFFUSER ASSEMBLY
DOME/DISC DIFFUSER LAYOUT (TYPICAL TANK)
47
-------
FIGURE NO.12
STAINLESS STEEL PIPE SUPPORT ASSEMBLY
(14 GAGE 304 SS)
48
-------
4.5 DIFF08ER LAYOUT AND DISTRIBUTION
The specified minimum number of diffusers and layout were
based on the maximum projected airflow for the design period
and the minimum airflow and diffuser spacing for mixing and
solids suspension. Based on the minimum mixing criteria at
0.12 SCFM/sq. ft. of tank floor area, the minimum airflow for
the design was as follows:
All four aeration tanks 7,500 SCFM
One aeration tank 1,860 "
One aeration pass 470 "
In addition, a minimum airflow of 0.5 SCFM per diffuser was
specified.
Based on a maximum airflow per diffuser of 2.0 SCFM, the total
number of diffusers specified was 3,100 per tank or 12,400 for
the four aeration tanks. Based on a step feed mode of opera-
tion with return sludge being fed to the head end of the first
aeration pass and one-third of the primary effluent being fed
to the head end of each of the remaining three aeration
passes, estimated percentages of the total air required in
each pass were as follows:
Percent of total tank
Pass air required No. of diffusers
1 35 1,085
2 25 775
3 25 775
4 15 465
Total/tank 100 3,100
In addition, the above estimates of oxygen demand distribution
were verified by oxygen uptake studies in one of the operating
tanks. The studies were conducted by MDC staff personnel at
sixteen locations along the four passes of one aeration tank
prior to retrofitting.
Possible future alterations of the step-feed mode called for
flexibility of diffuser placement and density (tapering) in
the design of the diffuser grids. The additional excess 50
percent saddle capacity in the grids and the provision for a
49
-------
throttling valve at the drop pipe provided for flexibility and
fine tuning of the diffuser tapering as might be required.
It was planned for the first two aeration tanks to be
retrofitted first and then placed on line before completion of
the retrofit in Aeration Tank Nos. 3 and 4. These first two
tanks would be field tested and additional diffuser density
modifications would be incorporated into Aeration Tank Nos. 3
and 4 as needed.
Dissolved oxygen measurements were taken in Aeration Tank Nos.
1 and 2 soon after being placed in operation. Operational
changes since the initial design was completed had caused a
shift in the oxygen demand pattern. The dissolved oxygen
profiles indicated that more diffusers were needed at the in-
fluent end of the passes. Redistribution of the diffusers was
easily accomplished by use of the spare saddles specified in
the design. (Diffuser density and quantity information by
grid, pass and tank are contained on Figure Nos. 13 and 14).
4.6 BLOWER DESIGN AND OPERATION CONSIDERATIONS
No blower air handling capacity modifications were planned as
part of the aeration system retrofit. The existing Brown-
Boveri 60,000 SCFM rotary vane blowers were tested during the
retrofit feasibility study and found to be suitable for use
with the new fine pore diffuser system. Although preretrofit
airflow from a single blower had been at the 60,000 SCFM
level, the new fine pore aeration system would require less
than 30,000 SCFM. By inlet guide vane adjustment, turndown of
the blowers was possible to a surge point of approximately
8,000 SCFM. The only cost of turndown was in the reduced ef-
ficiency of the blower at lower airflow output rates.
(Reducing a blower output from 40,000 to 20,000 SCFM increases
power consumption from 30 KW/1000 SCFM to 40 KW/1000 SCFM.)
The only modification to the blowers as part of the retrofit
would be the provision for automatic surge protection for each
blower. (Specific blower performance data is contained in Ap-
pendix I-C) .
The only modification required for the air filtration system
would be the installation of American Filter Co. "Biocell"
cartridge filters and frames in the intake plenum just after
the existing oil screen filters. With the installation of the
50
-------
FIGURE NO. 13
PLAN SKETCH WITH NUMBER OF DOMES
PER GRID, PASS, AND TOTAL
EFF
PE
I
HAS
I
71*
147
83
209
1
76
140
95
219
2
87
115
97
186
3
87
103
103
160
4
98
97
115
100
5
124
95
140
95
6
136
96
160
95
7
PE
4
PE
2
t
DOMES/PASS 679 + 793 + 793 + 1064
GRID
3329
* denotes number of domes per grid
RAS denotes Return Activated Sludge
PE denotes Primary Effluent Cone third per feed pt )
EFF denotes Effluent from aeration tank
51
-------
FIGURE NO,14
PLAIN SKETCH WITH OVERALL DENSITY PER GRID
EFF PE
4 4
RAS
L
7.8*
3.8
6.7
2.7
1
7.3
4.0
5.8
2.5
2
6.4
4.8
5.7
3.0
3
6.4
5.4
5.4
3.5
4
5.7
5.7
4.8
5.6
5
4.5
5.8
4.0
5.8
6
4.1
5.8
3.5
5.8
7
t
PE
\
PE
GRID
* denotes overall diffuser density per grid based
on number of domes per grid and mid-depth plan
area per grid (actual grid density is greater
than values shown). Density = sq.ft./dome
52
-------
new filters, 95 percent of all particles 0.3 microns and
larger would be removed from the air supply.
4.7 AIRFLOW MEASUREMENT AND DISTRIBUTION
The original airflow measurement and control system would
remain in operation with modifications to the measurement and
control instrumentation to adjust for the significant reduc-
tion of airflow throughout the system. The original airflow
measurement equipment consisted of a 12-inch venturi meter on
the head end of each aeration pass air supply line and one,
60-inch venturi meter on the main air supply pipe located be-
tween the blower building and the aeration tanks.
Airflow distribution modification would be accomplished by
designing the fine pore diffuser system to operate with equal
airflow rate to all diffusers under normal operating condi-
tions and to distribute the diffusers (tapering) according to
the oxygen demand throughout the aeration tank. Airflow ad-
justment from pass to pass would be accomplished by adjusting
the 12-inch control valves on the air line to each aeration
pass. Further fine tuning of air distribution within a pass
would be possible by adjusting the 4-inch control valves on
each of the seven drop pipes feeding the fine pore diffuser
grids.
4.8 DISSOLVED OXYGEN/AERATION CONTROL SCHEME
The original design in 1968 provided for dissolved oxygen
measurement and airflow control instrumentation. This mode of
control would be continued for the fine pore retrofit as well.
DO probes and meters manufactured by the pHOX Co. were in-
stalled at the half-way point along the length of each aera-
tion pass with a submergence of about 3 feet. This instrumen-
tation was linked to the airflow control instrumentation.
Calibration of the continuously recording DO instrumentation
would be accomplished by MDC laboratory personnel on an un-
scheduled basis as deemed necessary. A laboratory calibrated
portable DO probe and meter would be used to measure mixed
liquor dissolved oxygen at the location of the in-place DO
probe. The in-place DO meter would then be adjusted as neces-
sary to agree with the reading from the portable unit.
53
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4.9 CONTRACT DOCUMENTS AND BID
MDC staff performed the detailed final design and preparation
of the contract specifications and drawings. The contract
documents required the bid to be made by the aeration equip-
ment manufacture and not by general contractors. The purpose
of this requirement was to place total responsibility for the
retrofit contract squarely upon the aeration equipment
manufacturer. The scope of work included:
1. all in-tank aeration equipment and piping,
2. air filtration equipment,
3. removal of the old existing coarse bubble system,
4. cleaning of the aeration tanks, and
5. installation of all the new equipment.
Bids were advertised in February 1982. The three bidders
were: The Norton Co., Worcester, MA; Sanitaire, Milwaukee,
WI; and The Gray Engineering Group, Toronto, Canada. The suc-
cessful bidder was the Norton Co. Installation work began in
the summer of 1982. Aeration Tank No. 1 was completed in
August, Aeration Tank No. 2 in September, and Aeration Tank
Nos. 3 and 4 were completed in November 1982.
4.10 DESCRIPTION OF FINE PORE DIFFUSER EQUIPMENT PURCHASED
The fine pore dome diffuser equipment installed in Aeration
Tank Nos. 1 through 4 is the Norton Dome Diffuser Aeration
System (DDAS). Each diffuser is a 7-inch diameter porous
ceramic dome which is secured to a UPVC plastic pipe saddle
by a dome orifice bolt. Air emerges from the 4-inch grid
piping network at each saddle location up through a hollow
plastic dome bolt which contains a 13/64-inch diameter orifice
in the bolt side wall. Air then fills the cavity between the
saddle and under side of the ceramic dome where it disperses
through the wall of the dome. Neoprene gaskets seal the dome
at the dome bolt location and saddle. The dome saddle is ce-
mented to the 4-inch diameter UPVC grid pipe. Figure No. 7
contains a sketch of the diffuser and pipe support assemblies.
The pipe grid system is supported and anchored to the aeration
tank floor by a Norton designed stainless steel bracket which
allows for 1/8-inch vertical increments of adjustment. The
support bracket is secured to the concrete floor slab with two
54
-------
1/4-inch diameter stainless steel expansion anchor bolts. The
4-inch UPVC air piping is attached to the support bracket by a
standard commercially available stainless steel gear clamp.
Although 3,100 diffusers were specified for each aeration
tank, the actual number of diffusers installed in each tank is
3,329. The distribution of diffusers by grid and aeration
pass is contained on Figure No.13.
4.11 INSPECTION AND TESTING
During all phases of the installation, MDC personnel con-
tinuously inspected the completed work on a grid-by-grid
basis. Alignment of piping and diffuser elevation were
checked and verified for proper location and elevation. All
diffusers were installed and leveled to tolerance of +/- 1/8-
inch. The 7-inch ceramic dome diffusers were inspected after
installation for proper gasket placement and bolt torque.
Bolt torque was especially important because of the limited
allowance for torque load error associated with the plastic
dome bolts (25 inch-pounds maximum torque).
Upon completion of the installation in each tank, clean water
was introduced to a level 3 inches above the top of the dome
diffusers. Grid levelness was checked and verified, and a
system air distribution and leak test was performed. After
all corrections were made to assure uniform air distribution
and no leaks at pipe fittings, saddle assemblies and around
gaskets, the water level was slowly increased to full depth
while observing the air distribution pattern. The aeration
tank was then placed in operation.
55
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5.0 OPERATIONAL PERFORMANCE AND EVALUATION
5.1 SYSTEM STARTUP
Prior to the startup of Aeration Tank No. 1 with new fine pore
aeration equipment in mid-August 1982, the average air usage
over the previous 2 months was 64 MCFD (Mil. Cu. Ft./Day), and
the blower power usage over the same period averaged 31,000
KWH/day. During the same period MLSS ranged from 2,500 to
4,000 mg/1, and blower discharge pressure ranged from 7.5 to
7.7 psig. Air supply was controlled automatically during this
period, with air valves controlled by signals from DO probes
in each pass. An average dissolved oxygen concentration of 1
mg/1 was usually maintained in each pass.
Upon startup of the new fine pore aeration system in Aeration
Tank No. 1, air usage immediately dropped to 54 MCFD, and
blower power usage dropped to 28,000 KWH/day.
Aeration Tank No. 2 was placed on-line with the new equipment
at the first of September. During late August MLSS concentra-
tions had been increasing, and air supply was intentionally
increased over the preretrofit baseline levels. As the MLSS
concentration increased to over 5,000 mg/1, the greater air
requirements began to affect the different pressure require-
ments of the coarse and fine pore systems which were on-line
concurrently and being controlled by the same automatic
airflow control system.
The fine pore systems in Aeration Tank Nos. 1 and 2 received
less air than required, and anaerobic conditions occurred
causing sludge bulking and subsequent loss of solids in the
final effluent. Air supply to the entire four-tank system was
increased until a solution to the air distribution problems
could be found. Sludge wasting was increased to lower the
MLSS concentration to the 2,500 mg/1 design range and,
thereby, lower the total oxygen demand requirements.
By the first of November 1982 the installation of the entire
project was complete. With all four aeration tanks on-line
with the new fine pore aeration equipment, air usage dropped
to 36 MCFD, and power fell to a level of 22,000 KWH/day.
(These levels are approximately 60% and 70% of preretrofit
conditions, respectively.) For the remainder of 1982 the sys-
56
-------
tem was operated at these levels. During this period the
automatic air control instrumentation was adjusted, and an
economical operating range was investigated.
During the first week of 1983 an unexpected increase in MLSS
concentration caused air distribution problems and a large in-
crease in blower power usage. At the same time the automatic
control system did not perform as planned. Blower discharge
pressure was greater than necessary to deliver air to all the
passes, and air supply to some passes was reduced to levels
lower than the minimum recommended values required for solids
suspension and to prevent water-side fouling of the ceramic
diffusers.
In mid-January 1983 the aeration system was placed in the
manual mode of operation, with DO probes used for monitoring
purposes only. In the automatic air control mode the blower
discharge pressure varied from 7.1 to 7.4 psig. After switch-
ing to manual air control operation, the blower discharge
pressure was adjusted to 6.8 psig and all 12-inch air control
valves on aeration pass lines were locked fully open. Air
usage dropped slightly, but power consumption fell by over 10
percent. Further adjustment to the blower inlet guide vane
positioning resulted in an additional 10 percent reduction in
power draw at the blowers.
During April 1983 influent channel air usage was reduced by
one-half the previous rate of use. These reductions brought
the total air usage to 22 MCFD and power consumption to 15,000
KWH/day.
As was noted in the pilot testing of fine pore diffusers in
1979, foaming of the aeration tanks became worse after the
start-up of the new fine pore system. It was determined that
high MCRT's (greater than 3-5 days) caused foaming to increase
above an acceptable level. Short-term remedial action to
reduce foam consisted of reducing the mixed liquor dissolved
oxygen concentration to zero or near zero.
5.2 OPERATING CONDITIONS
Average operating conditions for the period from retrofit im-
plementation through the off-gas testing program are contained
in Table Nos. 2, 3, 4, 5, and 6, and also in Appendix I-C.
The design BOD loading was estimated to be about 30,000
57
-------
lbs./day to the secondary treatment system in 1982 and about
3 3/000 lbs./day in 1985. Average daily wastewater flows for
these years were projected to be 46.4 MGD for 1982 and 48.5
MGD for 1985. Generally, wastewater flow rates have exceeded
the design projections by a small amount, but BOD loading has
lagged behind the projections by a greater amount.
MLSS concentration, which was assigned a design criteria range
from 2,000 mg/1 to 2,500 mg/1, has varied widely over the
years since the retrofit started up. Concentrations as high
as 6,000 mg/1 have been measured, and the average MLSS con-
centration was much greater than the upper limit design value
of 2,500 mg/1. This high solids inventory in the aeration
system has caused oxygen demand to increase and aeration ef-
ficiency to lower, thus keeping energy costs up. In addition,
high MLSS concentrations mean longer MCRT values. Foaming be-
comes a problem under these conditions and oxygen transfer ef-
ficiency is adversely affected as well.
5.3 OPERATIONAL CONTROL
The primary control used in the operation of the aeration sys-
tem is dissolved oxygen concentration. This control is ac-
complished manually by observing the dissolved oxygen con-
centration in the fourth pass of each of two aeration tanks
twice daily and adjusting blower output to achieve a positive
DO in the fourth aeration pass for at least 12 hours per day.
The positive dissolved oxygen concentration usually occurs be-
tween 12 midnight and 12 noon each day. Generally, the entire
aeration system operates at a mixed liquor dissolved oxygen
concentration of less than 0.5 mg/1.
Diffuser air sparge rates vary within the design range as the
demand for oxygen changes. The established mode of operation
is to leave all aeration pass control values fully open, al-
lowing all diffusers to sparge at approximately equal rates
throughout the system. Should dissolved oxygen concentrations
increase in some aeration passes or tanks, air supply throt-
tling is initiated at the individual aeration pass or passes
having the greater DO concentration. Throttling is not con-
tinued to a point below which airflow to a pass would be less
than the minimum airflow to achieve mixing and solids suspen-
sion (0.12 SCFM/sq. ft.) or less than 0.5 SCFM per dome.
58
-------
5.i TREATMENT PERFORMANCE
The water quality of the plant effluent remains consistently
high after the implementation of fine pore aeration. Effluent
BOD and suspended solids concentrations nearly always remain
below 10 mg/1. No specific qualitative or quantitative infor-
mation is available concerning before and after retrofit ef-
fluent characteristics and treatment performance.
5.5 AERATION PERFORMANCE EVALUATION
5.5.1 General
An extensive aeration system performance evaluation has been
undertaken at the MDC treatment facility as part of the
ASCE/EPA Oxygen Transfer Study. From September 1985 through
August 1987 Aeration Technologies, Inc., conducted off-gas
testing during eleven separate site visits. Over 340 in-
dividual off-gas tests were performed in Aeration Tank No. 2
to measure and record aeration performance over time. The
results of the field off-gas measurements were compared with
plant water quality data and operating conditions for the
periods in which testing was performed.
Table No. 7 contains a listing of the eleven site test visits
together with a brief description of the type of testing per-
formed. The eleven site visits are graphed chronologically
on Figure No. 15 .
The first two site visits were for the purpose of equipment
and facility checkout. Only specific points in the aeration
system were tested during these visits. The first full test
of Aeration Tank No. 2 began on November 12, 1985. A total of
seven full-tank tests were performed over the two-year period.
The initial full tank test in November 1985, and the second
full-tank test in March 1986 used a sampling plan consisting
of four replicate tests at each of the influent, middle, and
effluent thirds of each aeration pass. (This sampling plan,
designated as Sampling Plan "A", is shown graphically on
Figure No.16). For the remaining five full-tank tests, a sam-
pling plan using one replicate at each third point, but with
three sets of tests for each site visit was adopted. It was
believed that the reduced time necessary to test the total
tank on a once-through basis would be more representative of
59
-------
Table 7
OFF-GAS TEST CHRONOLOGICAL SUMMARY
Test
Start Date Test Description Designation
09-14-85 Preliminary Checkout of Equipment PI
10-15-85 Start Cleaning of Aeration Tank
10-21-85* Preliminary Checkout of Equipment P2
11-12-85** Full Testing 1A
12-19-85 Influent Point Testing SI
03-24-86** Full Testing 2A
04-01-86 Diurnal Testing S2
07-14-86*** Full Testing 3B
02-04-87*** Full Testing 4B
04-22-87*** Full Testing 5B
05-01-87 Starting Cleaning of Aeration Tank —
06-18-87*** Full Testing 6B
08-13-87*** Full Testing 7B
*Conducted in Aeration Tank No. 1 (Aeration Tank No. 2 down
for cleanining).
**Four replicate tests per sample location and one excursion
through the aeration tank.
***0ne test per sample location and three excursions through
the aeration tank.
60
-------
PI P2
Si
1A
hrtrt
¦H-f
S2
2A
FIGURE NO. 15
TESTING AND TANK CLEANING TIME SUMMARY
LEGEND: 1A - "A" designates full test with four replicate tests
per sample location and one pass through the aera-
tion tank.
3B - "B" designates full test with one test per sample
location and three passes through the aeration
tank.
PI - Preliminary tests.
SI, S2 - special testing (influent point and diurnal,
respectively).
I I 1
IB 5B IB
>1111
>IM
1111
J F M A
A S
N D
JFMAMJJASOND
1986
J F M A
MJJASOND
1987
uFirst Cleaning of Aeration Tank No. 2.
Started October 15, 1985
l-Second Cleaning of Aeration
Tank No. 2. Started May 1, 1987
-------
FIGURE NO.16
OFF-GAS SAMPLING PLAN "A"
EFF
PE
4
RAS
I
37* 39
38 40
33 35
34 36
13 15
14 16
9 11
10 12
1
2
41 43
42 44
29 31
30 32
17 19
18 20
5 7
6 8
3
4
1 3
2 4
5
45 47
46 48
25 27
26 28
21 23
22 24
6
7
PE
t
PE
t
PASS
GRID
* Denotes test number and sample location for tests con-
ducted on November 12, 13, 14, 1985 and on March 24 and
25, 1986. Four replicate tests at each sample location
(one excursion through the aeration tank per site visit).
62
-------
actual performance conditions in the aeration tank. (This
second sampling plan, designated as Sampling Plan HBM is shown
graphically on Figure No. 17).
Two special tank tests were conducted on Aeration Tank No. 2
as part of the overall study. These tests consisted of an in-
fluent point test at each pass within 2 months after the first
tank cleaning, and a diurnal test at one point in the aeration
tank to determine the variation in performance over a twenty-
four hour period.
The off-gas test equipment and analysis procedures were in ac-
cordance with the project "Manual of Methods for Fine Bubble
Diffused Aeration Field Studies." Photo Plate P-l, Appendix
I-B, contains photographs of the off-gas analyzer apparatus
and the off-gas collection hood. Only one hood was used for
the "A" sampling plan, while two identical hoods were used for
the "B" sampling plan.
The results of all off-gas testing are summarized in the
tables and figures at the end of this report. Appendix I-A
contains a summary of individual test run results plus the
whole tank and pass airflow weighted results and the average
weighted results by pass and whole tank. Appendix I-D con-
tains the complete report of dynamic wet pressure (DWP) test-
ing conducted on several sample diffusers sent to the Univer-
sity of Wisconsin for evaluation.
Plant wastewater and process characteristics for the off-gas
test site visits are contained in Table Nos. 5 and 6 . These
data are plotted on Figure Nos. 18 through 21 versus elasped
study time, starting with the site visit in September 1985.
The results of oxygen transfer performance tests are sum-
marized in Table Nos. 8, 9, 10, and 11. Table No. 8 contains
the overall performance data by site visit for the whole tank
based on airflow weight averaged results from 36 to 48 in-
dividual test runs per site visit. Table Nos. 9 and 10 con-
tain individual test run and average alphaxSOTE and apparent
alpha values for sampling points 2-1 and 2-M (Aeration Pass 2,
influent end and middle). Table No. 11 contains the results
of the diurnal test conducted at sampling point 2-M in April
1986. Figure Nos. 22 through 31 contain plots of the data
contained in Table Nos. 8 through 11. The information is
plotted versus elapsed time from the beginning of the study.
Tank cleaning dates are indicated on the elapsed time graph.
63
-------
FIGURE NO. 17
OFF-GAS SAMPLING PLAN "B"
EFF PE
A i
RAS
I
PASS
1
1 1
W 1 I
* 1 1
« J
3-1
2-E
1-1
2
3
4-M
3-M
2-M
1-M
4
5
4-1
3-E
2-1
1-E
6
7
t
PE
PE
t
4
3
2
1
GRID
* Denotes samples location for all tests conducted after
April 2, 1986. One replicate test at each sample loca-
tion (three excursions through the aeration tank per site
visit).
64
-------
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65
-------
150
140
130
120
1 10
100
90
80
70
60
50
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20
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FIGURE NO. 19
PLANT PERFORMANCE DATA
Aug. 1, 1985
ELAPSED TIME, MONTHS
-------
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68
-------
Table 8
OVERALL AERATION PERFORMANCE FOR THE WHOLE TANK
AIRFLOW/
TOTAL
NEW
TEST
HL
TEMP.,
ALPHA x
DOME,
AIRFLOW,
SOTE,
APPARENT
ALPHA
X SOTR,
NEW SOTR,
DATE
NO.
DEG C
SOTE, X
SCFM
SCFM
X
ALPHA
LBS.
02/HR
LBS. 02/HR
OCTOBER 1985 - FIRST
CLEANING
11-12-85
1A
18.9
12.60
0.96
3194.9
28.2
0.45
417.28
932.25
03-24-86
2A
13.9
8.18
1.28
4260.8
28.2
0.29
361.24
1247.52
07-14-86
3B
22.5
9.40
2.40
7994.3
25.4
0.37
778.46
2107.14
02-04-87
4B
13.1
9.00
1.49
4952.6
27.3
0.33
461.65
1400.87
04-22-87
5B
14.7
11.36
1.41
4673.8
27.5
0.41
550.22
1331.89
MAY 1987
- SECOND
CLEANING
06-18-87
6B
21.6
9.35
0.85
2819.2
28.6
0.33
273.22
836.46
08-13-87
7B
24.7
9.88
2.20
7309.3
25.6
0.39
748.21
1942.09
AVERAGE
18.5
10.0
1.5
5029.3
27.3
0.4
512.9
1399.7
NOTES:
1A
- "A" TESTS DESIGNATE FOUR REPLICATE TESTS
PER SAMPLE LOCATION
AND ONE EXCURSION THROUGH THE AERATION TANK
3b - "B" TESTS DESIGNATE ONE TEST PER SAMPLE LOCATION AND THREE
EXCURSIONS THROUGH THE AERATION TANK.
-------
Table 9
SAMPLE LOCATION: PASS 2, INFLUENT (2-1)
START ALPHA X APPAREMT REPLICATE
DATE SOTE ALPHA MOOE
09-14-85 5.41 0.18
5.23 0.17
7.00 0.23
AVG. 5.88 0.20
11-12-85 14.59 0.47
14.80 0.48
13.75 0.44
13.79 0.44
AVG. 14.23 0.46
12-19-85 4.71 0.18
4.22 0.16
4.17 0.16
5.29 0.20
AVG. 4.60 0.17
3-24-86 8.58 0.32
8.17 0.30
8.07 0.30
9.14 0.34
AVG. 8.49 0.31
07-14-86 13.51 0.53
10.06 0.39
10.06 0.39
AVG. 11.21 0.44
02-04-87 9.16 0.33
8.82 0.32
9.22 0.33
AVG. 9.07 0.33
04-22-87 10.00 0.33
9.38 0.34
11.04 0.40
AVG. 10.14 0.36
06-18-87 13.48 0.45
12.09 0.40
11.74 0.39
AVG. 12.44 0.41
08-13-87 11.67 0.45
9.79 0.38
9.43 0.36
AVG. 10.29 (MO-
70
-------
Table 10
SAMPLE LOCATION: PASS NO. 2, MIDDLE (2-M)
START ALPHA X APPARENT REPLICATE
DATE SOTE ALPHA MOOE
11-12-85 15.63 0.52
16.77 0.55
16.82 0.56
16.24 0.54
AVG. 16.37 0.54
3-24-86 7.17 0.25
8.24 0.29
6.86 0.24
7.63 0.27
AVG. 7.48 0.26
4-1-86*
MAX. 11.25 0.41
MIN. 6.43 0.23
AVG. 8.27 0.30
7-14-86 11.42 0.46
9.08 0.37
11.38 0.46
AVG. 10.63 0.43
2-4-87 7.71 0.29
9.02 0.34
8.30 0.31
AVG. B.34 0.31
4-22-87 10.40 0.36
8.10 0.30
7.88 0.30
AVG. 8.79 0.32
6-18-87 11.46 0.40
9.88 0.34
11.83 0.41
AVG. 11.06 0.38
8-13-87 10.84 0.43
11.14 0.44
11.45 0.45
AVG. 11.14 0.44
* TOTAL OF 40 TESTS CONDUCTED
71
-------
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
7V
79
79
79
79
79
79
79
79.
79.
79.
79.
79.
79,
79.
79.
79.
79
79
79.
79.
79.
90.
90.
90.
90.
90.
90.
90.
90.
90.
90,
84
84.
84.
84.
84.
84.
84.
84.
Table 11
OFF-GAS TEST RESULTS FOR APRIL 1 AND 2, 1986 (DIURNAL STUDY)
HI-
TOTAL
ALPHA X
RUN
HE AS.
00.
TEMP,
ALPHA X
NO. OF
AIRFLOW
AIRFL0U,
NEU
APPARENT
SOTR,
DATE
TIME
HO.
OTE.X
NG/L
DEC C
SOTE, X
DOMES
SCFM
SCFH
SOTE, X
ALPHA
LBS. 02/HR
4-1-86
1130
1
7.50
0.18
15.2
7.81
245
1.10
269.5
28.3
0.28
21.81
4-1-86
1145
2
8.45
0.18
15.2
8.80
245
1.10
269.5
28.3
0.31
24.58
4-1-86
1230
3
8.50
0.18
15.2
8.85
245
1.10
269.5
28.3
0.31
24.72
4-1-86
1245
4
7.96
0.14
15.1
8.26
245
1.10
269.5
28.3
0.29
23.07
4-1-86
1330
5
8.11
0.13
15.2
8.41
245
1.10
269.5
28.3
0.30
23.49
4-1-86
1345
6
7.76
0.13
15.2
8.04
245
1.10
269.5
28.3
0.28
22.45
4-1-86
1430
7
7.07
0.12
15.2
7.32
245
1.10
269.5
28.3
0.26
20.44
4-1-86
1445
8
7.77
0.12
15.2
8.05
245
1.10
269.5
28.3
0.28
22.48
4-1-86
1530
9
7.49
0.07
15.4
7.72
245
1.10
269.5
28.3
0.27
21.56
4-1-86
1545
10
8.40
0.07
15.4
8.66
245
1.10
269.5
28.3
0.31
24.19
4-1-86
1630
11
6.67
0.06
15.4
6.87
245
1.10
269.5
28.3
0.24
19.19
4-1-86
1645
12
7.27
0.06
15.4
7.49
245
1.10
269.5
28.3
0.26
20.92
4-1-86
1730
13
7.48
0.06
15.3
7.70
245
1.10
269.5
28.3
0.27
21.50
4-1-86
1745
14
6.83
0.06
15.3
7.04
245
1.10
269.5
28.3
0.25
19.66
4-1-86
1830
15
6.72
0.06
15.3
6.92
245
1.10
269.5
28.3
0.24
19.33
4-1-86
1845
16
7.05
0.06
15.3
7.26
245
1.10
269.5
28.3
0.26
20.28
4-1-86
1930
17
6.90
0.06
15.4
7.11
245
1.10
269.5
28.3
0.25
19.86
4-1-86
1945
18
6.24
0.06
15.4
6.43
245
1.10
269.5
28.3
0.23
17.96
4-1-86
2030
19
7.38
0.06
15.3
7.60
245
1.10
269.5
28.3
0.27
21.22
4-1-86
2045
20
7.76
0.06
15.3
7.99
245
1.10
269.5
28.3
0.28
22.31
4-1-86
2230
21
7.06
0.06
15.2
7.27
245
1.10
269.5
28.3
0.26
20.30
4-1-86
2245
22
7.33
0.06
15.2
7.55
245
1.10
269.5
28.3
0.27
21.09
4-2-86
0030
23
7.50
0.06
15.1
7.73
245
1.30
318.5
27.4
0.28
25.51
4-2-86
0045
24
7.45
0.06
15.1
7.68
245
1.30
318.5
27.4
0.28
25.35
4-2-86
0230
25
7.44
0.05
15.1
7.66
245
1.30
318.5
27.4
0.28
25.28
4-2-86
0245
26
7.39
0.05
15.1
7.61
245
1.30
318.5
27.4
0.28
25.12
4-2-86
0430
27
8.51
0.06
15.1
8.77
245
1.30
318.5
27.4
0.32
28.95
4-2-86
0445
28
8.19
0.06
15.1
8.44
245
1.30
318.5
27.4
0.31
27.86
4-2-86
0630
29
8.00
0.08
15.0
8.26
245
1.30
318.5
27.4
0.30
27.26
4-2-86
0645
30
7.88
0.08
15.0
8.14
245
1.30
318.5
27.4
0.30
26.87
4-2-86
0730
31
8.41
0.07
14.9
8.68
245
1.30
318.5
27.4
0.32
28.65
4-2-86
0745
32
8.65
0.07
14.9
8.93
245
1.30
318.5
27.4
0.33
29.47
4-2-86
0830
33
7.48
0.09
14.9
7.73
245
1.20
294.0
27.6
0.28
23.55
4-2-86
0845
34
8.59
0.09
14.9
8.88
245
1.20
294.0
27.6
0.32
27.05
4-2-86
0930
35
10.83
0.15
14.8
11.25
245
1.20
294.0
27.6
0.41
34.27
4-2-86
0945
36
9.02
0.15
14.8
9.37
245
1.20
294.0
27.6
0.34
28.55
4-2-86
1030
37
9.86
0.25
14.8
10.33
245
1.20
294.0
27.6
0.37
31.47
4-2-86
1045
38
10.67
0.25
14.8
11.18
245
1.20
294.0
27.6
0.41
34.06
4-2-86
1130
39
9.83
0.13
14.8
10.20
245
1.20
294.0
27.6
0.37
31.08
4-2-86
1145
40
9.49
0.13
14.8
9.84
245
1.20
294.0
27.6
0.36
29.98
-
-
-
-
-
15.1
8.27
245
1.17
286.7
27.9
0.30
24.57
-------
14
13
12
1 1
10
9
8
7
6
5
4
3
2
1
0
FIGURE NO. 22
OVERALL PERFORMANCE FOR TOTAL TANK
AVG. ALPHA X SOTE FOR
AERATION TANK NO. 2
Aug. 1, 1985
ELAPSED TIME, MONTHS
-------
FIGURE NO. 23
OVERALL PERFORMANCE FOR TOTAL TANK
0.9
0.8 -
—j
<
I
a.
t-
z
Id
K
<
CL
Q.
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0.7 -
0.6
0.5 -
0.4 -
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0.2 -
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0
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L
AVERAGE APPARENT
ALPHA FOR
AERATION TANK NO- 2
1986
I
1987
T
8
Aug. 1, 1985
12 16
ELAPSED TIME, MONTHS
20
24
28
-------
FIGURE NO. 24
OVERALL PERFORMANCE FOR TOTAL TANK
35
AVERAGE SOTE
-J
ui
Z
LlI
o
OC
U
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>"
o
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y
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15
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00
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0
9
8
7
6
5
4
3
2
1
0
FIGURE NO. 25
OVERALL PERFORMANCE FOR TOTAL TANK
r»
CO
in
00
i
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FIGURE NO. 28
ALPHA x SOTE - PASS NO. 2 - MIDDLE
•Aug. 1, 1985
ELAPSED TIME, MONTHS
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FIGURE NO. "30
OFF-GAS TEST RESULTS FOR APRIL 1 AND 2, 1986 (DIURNAL STUDY)
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FIGURE NO. 31
OFF-GAS TEST RESULTS FOR APRIL 1 AND 2, 1986 (DIURNAL STUDY)
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-------
5.5.2 Oxvcren Transfer Efficiency
The overall whole-tank oxygen transfer efficiency, expressed
as alpha x SOTE, averaged 10.0 percent for the two-year study
period. The average whole-tank alphaxSOTE test results varied
from a high of 12.6 percent to a low of 8.2 percent throughout
the study. The whole-tank average values are based on seven
site visits from November 1985 to August 1987 and represent
the summary of over 340 individual test runs. During each
site visit each aeration pass was tested at the influent,
middle, and effluent third points. Sampling Plan "A" repli-
cated each sample location four times consecutively, and Sam-
pling Plan "Bn replicated overall whole-tank off-gas results
three times for each site visit.
Evaluation and comparison of all test results by specific
parameter indicates that oxygen transfer efficiency varies in
an unexplainable trend over time, from test to test, and from
sample location to sample location. This varability is con-
sistent with the variation in wastewater characteristics and
process operating parameters throughout the study period.
Also, diffuser air leaks caused changes in air distribution
and special oxygen transfer efficiency.
An example of the variation in alphaxSOTE at various times
and points is illustrated as follows:
Sampling Criteria
alphaxSOTE, Percent
Avq. Min. Max.
~ average whole-tank
weighted results
for seven site visits
9.97
8.18
12. 60
~ average whole-tank
weighted results for
February 1987 site visit
9.00
8.04
10.11
83
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Sampling Criteria
~ average sample location
2-1 results for nine
site visits
~ average sample location
2-1 results for February
1987 site visit
~ average sample location
2-M results for eight
site visits
~ average sample location
2-M results for February
1987 site visit
~ average sample location
2-M results for April
1986 diurnal study
From the above data it can be shown that the range in oxygen
transfer efficiency varies over a wide range depending upon
the time frame and number of sample points and tests used for
comparison. Replicate test-run results at one sample location
and for one site visit were relatively close (ranged within
+/- 5 to 10 percent of the average) , while average whole tank
weighted results for a site visit were also relatively close
(+/- 2 to 12 percent of the average). However, diurnal varia-
tions in a twenty-four hour period at one sample location
varied as much +/- 3 0 percent of the average alphaxSOTE. The
overall whole-tank weighted average results for the two- year
study period ranged from +/~ 22 percent of the average, while
the range in results at specific sample locations over the
same period was up to +/- 50 percent of the average value.
With this variability, a large number of tests and wide time
base are necessary factors in estimating overall average per-
formance characteristics which are representative of the
general system performance.
84
alphaxSOTE. Percent
Avq. Min. Max.
9.57 4.60 14.23
9.07 8.82 9.16
10.26 7.48 16.37
8.34 7.71 9.02
8.27 6.43 11.25
-------
5.5.3 Clean Water and Mixed Liquor Performance Comparison
Each off-gas test result is compared with the expected clean
water performance value based on Standard Oxygen Transfer test
data. These data are plotted on Figure No. 24 for the average
whole-tank test results by site visit. Figure No. 9! also
contains a plot of clean water and alphaxSOTE performance ver-
sus airflow per diffuser for the average whole-tank test
results. Reported clean water test data are also plotted on
the Figure. The expected average SOTE value for the Hartford
design is 27.5 percent, and the average whole-tank alphaxSOTE
as measured by off-gas testing is 10.0 percent.
5.5.4 Measured Alpha
The measured alpha factor value for the average whole-tank
test results is 0.37 with a range of 0.29 to 0.45. Individual
sample point alpha values ranged from less than 0.2 to up to
about 0.6. Usually the very low alpha values were measured at
influent feed point sample locations in any of the aeration
passes.
5.5.5 Physical Observations
The photographs contained in Appendix I-B indicate observa-
tions made during routine operation and tank cleaning. Photo
Plate P-2 contains photographs of Nocardia foaming conditions
experienced from time to time during the study period as well
as surface bubble patterns at the tank inlets.
Observations made during the tank cleaning operations were
very informative. Photo Plates P-3, P-4, and P-6 illustrate
the degree of external slime buildup on the diffusers. Even
after initial hosing (Photo P-3.2), significant amounts of
foulant remained on the diffusers.
The wet, slimy deposits, which appeared to be mostly organic,
uniformly covered the exterior surface of the diffusers.
After initial hosing, patchy deposits, which appeared to be
inorganic, remained on the surface of most of the diffusers.
Also, these deposits covered the vertical sides of most dif-
fusers, and acid cleaning did not appear to be effective in
removing the materials from the sides of the diffusers.
85
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Much of the deposited material on the outside of the diffusers
was inorganic, and significant amount of grit and silt were
present at the inlet points of Pass Nos. 2, 3, and 4 (primary
effluent feed points) . These deposits can be seen in the
photographs (Photo P-5.1 and P-6.2).
The inside (air side) surface of diffusers removed for
laboratory testing at a later date contained small amounts of
dried-on scale which probably originated from mixed liquor
intrusion into the air pipe grid system through openings
caused by broken dome bolts, cracked gaskets and other leaks
in the air piping system. The air side deposits did not ap-
pear to be significant, particularly when compared to the out-
side (liquid side) deposits on the diffuser.
5.5.6 Laboratory Testing
Several diffuser domes were removed from the aeration tank
during the cleaning period in May 1987. Uncleaned and acid
cleaned samples were shipped to the University of Wisconsin
for testing and evaluation. A new, unused dome was also in-
cluded with the used domes.
The results of the laboratory testing are contained in Appen-
dix I-D. Testing of the uncleaned diffusers indicated that
the Dynamic Wet Pressure (DWP) at points of deposited
materials was extremely high. Acid cleaning reduced DWP
values greatly, but to values still twice as high as for new
diffusers.
5.6 EFFECT OF CLEANING ON PERFORMANCE
5.6.1 Cleaning Frequency
There is no routine cleaning program for, or a basis for
cleaning the fine pore diffuser equipment at the Hartford
facility. Approximately one year after being placed in serv-
ice, all four aeration tanks were dewatered one at a time and
the aeration equipment inspected. No cleaning was performed
during this inspection program. Prior to the beginning of
86
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off-gas testing in Aeration Tank No. 2 in the fall of 1985,
the tank was dewatered and the aeration equipment cleaned.
Photo Plates P-3, P-4, and P-5, Appendix I-B, depict the con-
dition of the dome diffusers after three years of continuous
service. The other three aeration tanks were also cleaned in
the fall of 1985 for the first time.
Only Aeration Tank No. 2 was cleaned a second time in May
1987. The reason for cleaning the tank was to develop before
and after cleaning oxygen transfer efficiency data for the
ASCE/EPA Oxygen Transfer Study. There was no performance
basis used to initiate cleaning in May 1987 rather than at
some other time. Photo Plates P-6 through P-10 contain un-
clean and cleaned diffuser photographs for the May 1987 clean-
ing.
5.6.2 Cleaning Method
The cleaning method used both times is known as the "Milwaukee
Method" which uses hosing and acid application. This method
has been used at the Milwaukee wastewater treatment plants for
several years. A high pressure water jet is applied to the
diffuser surface followed by acid spraying and hosing. The
rational is to first hose off the easily removable foulants so
that the applied acid can solubilize the inorganic precipitate
inside the pores of the diffuser. A second hosing is then
performed to remove the solubilized foulant and residual acid.
The materials used for this method are: high or low pressure
water hosing equipment, acid spray applicator, and acid solu-
tion.
The cleaning procedure is as follows:
1. dewater the aeration tank with the air supply on
while dewatering.
2. clean the diffuser grid system by high pressure
hosing with water (either tap or final effluent)
while the air supply is on and at a sparge rate of
approximately 1 SCFM per diffuser.
3. apply approximately 50 ml of acid to the surface of
the diffuser using the spray applicator. No air is
discharged through the diffuser during the acid ap-
plication period.
4. let the acid remain on the diffusers for 30 minutes.
87
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5. scrub the diffuser with a cleaning brush as neces-
sary.
6. hose the diffusers off again for one minute or as
long as necessary to remove all of the residual acid
and solubilized materials with the air supply
remaining on throughout the final hosing.
The acid solution used for cleaning is a commercially avail-
able cleaning compound known as MZEP." The active ingredient
is 22 percent HC1 with surfactants added to aid the cleaning
process. This cleaner was found to be much more effective
than using straight 14 percent HC1 solution on diffuser
samples cleaned in the laboratory. Photo Plates P-7 and P-8,
Appendix I-B, contain photographs of the cleaning process.
5.6.3 Air Distribution and Leak Testing
Immediately after cleaning the aeration equipment as described
above, air distribution and leak testing was conducted prior
to placing the aeration tank back on-line. Plant effluent was
introduced to the aeration tank until the diffuser grid was
submerged by 2 to 3 inches of liquid. Airflow was adjusted
to approximately 0.5 SCFM per diffuser, and observations were
made for air distributions and leaks.
All gaskets, dome bolts, and other air leaks were repaired
throughout the tank, and any leveling of, or repairs to pipe
supports was accomplished at that time.
Photo Plates P-9 and P-10, Appendix I-B, show the effect of
gasket leaks at individual diffusers. Photo Plate P-10.1
shows the effect of a broken pipe support on levelness of the
diffuser grid.
Diffuser leaks were identified by the bubble pattern generated
at each diffuser (Photo Plate P-9.1). Fixing of the leaks
consisted of the following procedure:
1. loosen dome bolt and rotate dome and gasket on
saddle about 15 degrees.
2. tighten dome bolt to 2 5 inch-pounds of torque with
torque wrench.
3. repeat step no. 2 with further rotating of dome as
necessary if first attempt was not successful.
4. install new gaskets if rotation of dome does not
stop leak after three or four attempts.
88
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Photo Plate P-ll contains two photos of used dome gaskets
which were replaced because of air leaks caused by the cracks
in the gaskets. These gaskets could not be prevented from
leaking by following the above procedure.
In the course of cleaning an aeration tank and repairing
leaks, several gaskets required replacement, and several plas-
tic dome bolts were broken during the repair work. During the
first cleaning in October 1985, several dome bolts were inad-
vertently overtightened by mistake. Some bolts failed before
the tank was filled and placed in service. However, several
bolts failed after the tank was placed on-line. In Aeration
Tank No. 4 the number of bolt failures was significant enough
to require that the tank be taken off line, dewatered, and the
broken bolts replaced within a few days of cleaning and
start-up.
5.6.4 Post Study Period Cleaning Observations
Aeration Tank No. 2 was out of service from September 25
through October 19, 1988 for cleaning and repairs to the dome
diffuser aeration equipment. After dewatering the tank, the
following were noted:
1. over 400 domes were missing from the dome saddles
due to broken plastic dome hold-down bolts.
2. over 500 domes were on the dome saddles, but the
plastic dome hold-down bolts had broken.
3. the pipe grid hold-down gear clamp supports on one
grid were broken, and the plastic grid piping had
separated.
The broken plastic dome bolts were replaced with stainless
steel bolts, and over 250 new dome gaskets were installed
where old, defective gaskets could not be reused.
Between October 19, 1988 and November 14, 1988, coarse bub-
bling began in Aeration Tank No. 2. Approximately 75 coarse
bubble locations were identified. The cause of coarse bub-
bling was probably due to additional plastic dome bolt
breakage.
89
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The cost to clean and repair Aeration Tank No. 2 was over 3
times more than for earlier individual cleanings.
5.7 BEFORE AND AFTER CLEANING OTE RESULTS
Prior to the initial tank cleaning in October 1985, only
preliminary influent sample point off-gas tests were performed
on Aeration Tank No. 2. Full-tank testing was conducted about
three weeks after the aeration tank was placed back in serv-
ice. Influent point off-gas testing was again conducted about
a month later in Aeration Tank No. 2.
The second diffuser cleaning was bracketed by full-tank off-
gas tests before and after cleaning in May 1987. These whole-
tank aeration performance tests provide the most complete in-
formation on oxygen transfer performance for the whole tank
before and after cleaning.
The overall weighted tank alphaxSOTE value based on tests con-
ducted in November 1985 was 12.6 percent. These tests were
conducted within a month after tank cleaning. The apparent
alpha value for the overall tank performance was computed to
be 0.45. Based on tests conducted on the Aeration Pass No. 2
influent sample point in September 1985 (alphaxSOTE = 5.9 and
apparent alpha =0.2), it appeared that the cleaning was very
beneficial. However, further influent sample point testing in
December 1985 resulted in an alphaxSOTE value of 4.6 and an
apparent alpha of 0.17.
Noticeable coarse bubbling was observed at the inlet feed
points of all passes within the first month after cleaning.
Organic loading remained relatively constant throughout the
period from September through December 1985, and the average
soluble BOD was 38 percent of the primary effluent BOD for
this period. From plant wastewater quality data and observa-
tions of coarse bubbling, it was assumed that the diffusers
were fouling quickly after cleaning due to the buildup of
biological slime on the surface of the diffusers, particularly
at the influent points of each pass.
Just prior to the second tank cleaning in May 1987, off-gas
testing was conducted at the end of April. After cleaning and
start-up of Aeration Tank No. 2 in the first week of May 1987,
90
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organic loading to the aeration system increased and solids
inventory began to rise. Post-tank cleaning off-gas testing
was delayed until the middle of June 1987 due to process up-
sets from the higher loading conditions.
The before and after results of off-gas testing for the May
1987 cleaning are summarized as follows:
Parameter
Before
After
Pri. Eff. BOD, mg/1
49
112
Final Eff. BOD, mg/1
4
9
Plant Flow, MGD
62.3
47.2
MLSS, mg/1
3200
4500
MCRT, Days
7.9
9.7
Avg. alphaxSOTE, %
11.36
9.35
Apparent Alpha
0.41
0.33
Pass 2-1, alphaxSOTE, %
10.14
12.44
Pass 2-1, Apparent Alpha
0.36
0.41
Pass 2-M, alphaxSOTE, %
8.79
11.06
Pass 2-M, Apparent Alpha
0.32
0.38
transfer efficiency results
in Aeration Pass Nos.
1 and 4
for the June 1987 tests lowered the total average tank perfor-
mance results for the after cleaning tests to below those for
before cleaning. Also, the before cleaning results were the
highest measured results of the entire test period since the
initial tests conducted in November 1985.
Organic loading, MLSS, and MCRT increased significantly be-
tween the before and after testing. These wastewater and
process changes certainly effected the oxygen transfer perfor-
mance in an adverse manner in the after cleaning tests versus
the before cleaning tests.
Due to the wide range in values for wastewater characteris-
tics, process parameters, and off-gas results by sample loca-
tion and by test, a strong conclusion cannot be drawn regard-
ing quantitative changes in oxygen transfer efficiency as a
result of diffuser cleaning.
Although diffuser cleaning may have little effect upon changes
in oxygen transfer efficiency, the cleaning of diffusers on a
routine basis is beneficial. Diffuser cleaning removes
built-up deposits of both inorganic and organic materials
Q1
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which cause increased back pressure through the diffuser.
Secondly, diffuser cleaning provides for an inspection of the
aeration equipmeht and the undertaking of air distribution and
leak tests. Any necessary repairs to limit gasket and other
leaks and perform any other repairs constitutes good main-
tenance practice at the time of tank cleaning.
5.8 COST OF CLEANING
The cost of cleaning one aeration tank is based on cost data
for two cleanings of Aeration Tank No. 2 and one cleaning of
the other three aeration tanks. If cleaning frequency in the
future would be once per year, then the estimated costs
presented herein would represent annual cleaning costs.
The estimated costs by category, are as follows for one aera-
tion tank:
~ Labor for hosing, acid cleaning, and leak
repair (100 man-hours using 2 to 3 laborers
with some overtime) $ 2,000.00
~ Cleaning Chemical (55 gallon drum of ZEP) 250.00
~ Cleaning equipment and protective clothing 750.00
~ Spare parts for repair of equipment (gaskets,
bolts, domes, pipe supports, etc.) 1,500.00
TOTAL COST $ 4,500.00
The total cost per tank represents a per diffuser unit clean-
ing cost of $1.35 for each diffuser cleaned. The unit cost
would be less than $1.00 per diffuser when the miscellaneous
costs for maintaining the equipment are excluded from the to-
tal cost estimate.
The cleaning cost estimates do not include any allowance for
the expense of grit removal from the aeration tank. At some
point in the future significant deposits of grit will have to
be removed from the aeration tanks.
92
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Maintenance work to repair leaks and diffusers and piping will
increase as the aeration equipment gets older. At the time
cleaning was performed at Hartford, the aeration equipment was
3 years old. Leak repairs to diffusers involved between 5 and
10 percent of all diffusers. Cleaning at a future time may
well involve repair work to a larger percentage of the dif-
fusers.
From the condition of the gaskets removed during tank clean-
ing, it is conceivable that all gaskets may require replace-
ment with new gaskets in the near future. Plastic dome bolts
should be replaced with stainless steel bolts at the same
time. Also, the effectiveness of acid cleaning should be
evaluated in terms of diffuser headloss. As the aeration
equipment becomes older, diffuser headloss may increase to un-
acceptable levels, even with acid cleaning.
The estimated equipment longevity, based on cleaning results
and observation of equipment components removed at Hartford
is:
~ gaskets and plastic
dome bolts
~ ceramic domes
3 to 5 years until replacement
with new components
5 to 8 years until thorough
cleaning or replacement with
new domes
~ plastic grid piping over 10 years
system
The above longevity times are only estimates based on ex-
trapolation of information and observations made after three
to four years of operating experience at Hartford.
The average downtime required to clean each aeration tank was
one week, including draining and filling time. Cleaning was
scheduled for periods when total plant flow and organic load-
ing were expected to be at average or below average values to
minimize the effect of tank cleaning on plant operation and
performance. With one tank out of operation, the remaining
three tanks received a 33 percent increase in flow and organic
loading. No adverse effects on plant effluent quality oc-
curred during cleaning. However, if peak loading had occurred
93
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during cleaning, there could have been reduced effluent
quality due to reduced retention time in the aeration process
and possible diffuser air capacity limitations.
94
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6.0 ECONOMIC CONSIDERATIONS FOR PINE PORE AERATION
6.1 POWER USE
The baseline period energy consumption for one 3,000 HP blower
was 31,000 KWH/day with the original coarse bubble aeration
equipment. Total aeration energy consumption dropped to
15,000 KWH/day after the retrofit project was completed and
the new aeration system brought on line. Total plant electri-
cal consumption was 54,000 KWH/day for the baseline period.
(This value includes power for preliminary and primary treat-
ment, effluent pumping, secondary treatment, and sludge
processing). The total plant electrical consumption was
reduced to 4 2,000 KWH/day after the retrofit. The reduction
of 12,000 KWH/day represented a 22 percent decrease in total
plant electrical consumption for 1983.
Power use data and trends based on wastewater flow and
strength are presented in Table Nos. 2 and 4. Although ratios
for power per unit BOD removed vary over time, the clear trend
is that significantly less power is required per unit of BOD
removed for the fine pore retrofit versus the original coarse
bubble spiral-roll aeration system.
Significant fluctuations in this ratio could be caused by the
wide range of MLSS in the aeration system over the period of
record. The higher MLSS concentrations require greater amount
of oxygen, and therefore power, per unit of BOD removed. In
addition, the rate of change of power consumption for air
delivery is not constant over the full range of airflow for
the blowers at Hartford.
In August 1985 the Metropolitan District Commission retained
Metcalf & Eddy to investigate the feasibility of upgrading the
air delivery system by replacing are of the existing Brown-
Boveri 3,000 HP blowers with a more efficient blower. In
Metcalf & Eddy's report of January 1986, it was concluded that
the existing original blowers were not as efficient as new,
smaller blowers. The existing blowers had the following power
consumption-air delivery characteristics:
95
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Blower Air Delivery
SCFK
Power Consumption
KW/1000 SCFM
60,000
30,000
15,000
28.5
34.0
45.5
With post-retrofit air supply reduced to below 30,000 SCFM or
over a 50 percent reduction, the resulting power consumption
reduction was less than 40 percent due to the less efficient
operation of the blower at the reduced airflow output.
The Metcalf & Eddy report recommended that a new blower system
be installed for the channel aeration; its capacity being
7,500 SCFM; and that a new 25,000 SCFM blower be installed for
activated sludge aeration, replacing one of the existing
Brown-Boveri 3,000 HP units. The estimated payback of the
recommendations was about 3 years.
6.2 OXYGEN TRANSFER EFFICIENCY COMPARISON
The original coarse bubble spiral-roll aeration system is es-
timated to have an SOTE performance of between 6 and 7 per-
cent. A value of 6.25 has been selected based on test data
from the manufacturer and test results from the L. A. County
oxygen transfer study. The efficiency of this aeration equip-
ment is reduced to 4.4 percent (alphaxSOTE) when an alpha of
0.7 is assumed. The resulting OTE in mixed liquor with a DO
concentration of 2.0 mg/1 is 3.2 percent for the coarse bubble
system.
The average value for alphaxSOTE for all whole-tank tests con-
ducted on the fine pore aeration system in Aeration Tank No. 2
is 10.0 percent transfer. This represents 2.25 times the
transfer efficiency of the original equipment. The ratio of
2.25 is in general agreement with the ratio of airflows before
and after retrofit.
The comparison of SOTE and alphaxSOTE for each system is
presented graphically on Figure No. 11. Both specified and
"expected" SOTE efficiencies are plotted for the fine pore
dome diffusers. The "expected" efficiencies are based on
full-scale clean water test results for fine pore dome dif-
fusers tested and analyzed per the ASCE Standard Procedure.
96
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6.3 INCREASE IN ACTUAL EFFICIENCY
It appears reasonable to assume that the fine pore average ac-
tual efficiency (alphaxSOTE) is in the range of 9 to 10 per-
cent. The original coarse bubble spiral-roll system average
operating efficiency is estimated to be in the range of 4 to 5
percent (alphaxSOTE). The increase in actual efficiency rep-
resents 200 to 225 percent of the original system efficiency.
The retrofit design assumption was for an actual fine pore ef-
ficiency of about 17.5 percent (Figure No. 9 ), but this value
was based on a very unrealistic (by today's standards) alpha
value of 0.75. Even with an alpha of 0.5 the actual ef-
ficiency would be approximately 15 percent for the fine pore
system, or over 3 times more efficient than the original sys-
tem.
A doubling of transfer efficiency for this retrofit seems to
be reasonable based on the reported values for both power con-
sumption and airflow before and after the retrofit. Also, the
alphaxSOTE values measured in this system agree reasonably
well with the results from several other fine pore dome dif-
fuser systems tested using the off-gas method in the recent
past. (See EPA final report for specific results at other
locations.)
6.4 COST CONSIDERATIONS
The estimated capital cost of the retrofit based on the
consultant's estimate was between $1,115,000 and $1,830,000.
The actual total capital cost for the project was less than
$600,000, completely installed.
The installed cost on a per diffuser basis was less than
$50.00/diffuser including modifications to the instrumenta-
tion, additional air filtration, and all installation costs.
In-tank diffuser equipment and piping costs, alone, probably
represented half of the total cost of the project.
Annual operating savings were estimated to be over $200,000
for the first year of operation. A daily power reduction of
about 12,000 KWH was realized, and the electrical rate in 1983
was about $0.05 per KWH. Similar savings in the cost of
electricity have been observed for the following years.
97
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Annual maintenance costs for the fine pore system have not in-
creased significantly over maintenance costs for the coarse
bubble system. All four aeration tanks were cleaned in late
1985 in preparation for the ASCE/EPA Oxygen Transfer Study.
Up until that time, no cleaning or other maintenance had been
performed on the fine pore system.
The cost to clean each aeration tank in 1985 was approximately
$4,500, or $18,000 for all four tanks. The breakdown for
cleaning each tank is as follows:
Labor (100 man hours including overtime) $2,000.00
Chemicals (ZEP cleaner) 250.00
Cleaning Equipment and Protective Clothing 750.00
Spare Parts (domes, bolts, gaskets,
pipe hangers, etc.) 1,500.00
TOTAL TANK $4,500.00
The total downtime for cleaning a single four-pass aeration
tank was approximately one week, including draining and
refilling.
The cost of replacing domes, gaskets, and bolts with new
equipment would be approximately $35,000 for an entire aera-
tion tank. In addition, the removal of grit, debris, and
sludge could cost an additional $15,000. Total rehabilitation
of the fine pore diffuser system should not be required more
often than once every 5 to 8 years. However, gaskets and
plastic bolts may require replacement as often as every 3
years.
Payback periods of less than 3 years can be expected for re-
placement of spiral-roll coarse bubble aeration equipment with
full-floor coverage fine pore dome/disc aeration equipment.
This payback is predicated upon the ability to reduce blower
power usage through turndown and/or shutdown of blower units
after retrofitting with the new equipment.
98
-------
7.0 RECOMMENDATIONS
7.1 GENERAL
As a result of a thorough review of the Hartford Water Pollu-
tion Control Plant retrofit history and evaluation of over 2
years operating and oxygen transfer performance data as part
of the ASCE/EPA Oxygen Transfer Study, several recommendations
can be made regarding retrofit considerations for other
similar facilities. These recommendations are categorized as
follows:
1. Engineering Design
2. Equipment Design
3. Operation
4. Maintenance
5. Efficiency Considerations
6. Clogging Potential
7. Mechanical Reliability
8. Overall Advantages and Disadvantages
7.2 ENGINEERING DESIGN
Diffuser grid system and other in-tank air piping should be
designed for operational flexibility for delivery of oxygen as
required to specific sections of the aeration tank or process.
Spare diffuser saddle capacity should always be provided in
the design. Other methods of tapering air supply should be
provided in the design as well. Grid system layout should in-
clude a specified minimum number of grids to ensure tapering
capability and operational flexibility. Also, the grid system
design should facilitate easy cleaning of the aeration tank
when removal of bottom deposits becomes necessary.
Consideration should be given to the inlet or feed point
design. Adequate distribution and mixing of the influent are
necessary. If very low alpha values and the possibility of
heavy fouling occur at the influent points, the aeration
equipment design should address these conditions. the use of
a full-floor coverage coarse bubble grid at the influent point
might be more feasible than the use of a fine pore diffuser
grid.
99
-------
Dissolved oxygen measurement and control instrumentation
design should be kept as simple as possible. Only proven
technologies with a history of low maintenance should be con-
sidered.
Air supply piping should be sized for capacity considerations
throughout the design life period (usually 20 years). Piping
should provide for operational flexibility and tapering of the
air supply.
Air distribution considerations should include an understand-
ing of the oxygen demand profile in the system and methods for
accomplishing necessary tapering, either by grid number and
size selection or by control valves, or a combination of both.
Blower design or modification must be considered whenever
changing from coarse bubble to fine pore aeration. Airflow,
discharge pressure, and power consumption relationships must
be evaluated and understood with regard to the new operating
conditions. Net operating savings will be a direct result of
reduced electrical power draw of the blower system and not as
a result of increased oxygen transfer efficiency of the new
aeration equipment.
7.3 EQUIPMENT DESIGN
The fine pore diffuser equipment should be durable and func-
tionally simple. Systems using gaskets and plastic bolts
should be evaluated carefully. Currently available gasketing
systems are prone to leak and do not hold up for long periods
of time. Plastic dome bolts are subject to total failure if
overtightened or if temperature stresses develop after instal-
lation. Problems with either gaskets or dome bolts lead to
coarse bubbling (loss of oxygen transfer efficiency), mal-
distribution of air, and intrusion of mixed liquor into the
diffuser grid system.
In-tank air piping should be totally corrosion resistant.
Pipe supports should be manufactured of stainless steel and
designed for easy and precise leveling of the diffuser grid.
All piping grids should contain moisture blow-off units.
100
-------
7.4 OPERATION
The fine pore diffused aeration system should be operated
within the airflow range of the design. Minimum airflow rates
for solids suspension and mixing of the mixed liquor and mini-
mum airflow rates per diffuser to assure uniform distribution
of air throughout a grid must be maintained.
Minimum dissolved oxygen concentrations should be established
based on process and effluent quality considerations.
Monitoring of dissolved oxygen should be based upon maintain-
ing accurately measuring DO equipment.
MLSS concentrations should be maintained within design ranges
insofar as possible. Increases in MLSS inventories in the
aeration system increase oxygen demand and probably lower the
apparent alpha values.
7.5 MAINTENANCE
All fine pore aeration systems must be properly maintained to
ensure high operational efficiency. Routine inspection,
cleaning, and repair must be carried out as necessary. Dif-
fuser headloss, or dynamic wet pressure, and oxygen transfer
efficiency measurements provide useful information for clean-
ing frequency requirements. Observation of surface patterns
can provide information concerning coarse bubbling (possibly
due to biofouling of the diffusers or from gasket leaks) and
obvious air leaks. Major coarse bubbling problems should be
checked out immediately and repairs made as soon as possible.
Not only is oxygen transfer efficiency reduced as a result of
coarse bubbling, but diffuser system clogging is possible from
mixed liquor backflow into the air system.
7.6 EFFICIENCY CONSIDERATIONS
Retrofit design should be predicated upon sound performance
data. Valid Standard Oxygen Transfer information should only
be used in the design. Diffuser airflow rates, water depth,
and diffuser density should be the same for test result infor-
mation as for the proposed design conditions.
101
-------
Alpha factors in the range of 0.3 to 0.4 should be used for
fine pore diffuser systems. Higher values of the alpha factor
should not be used unless specific alpha factor testing has
been carried out, and the results verify that less conserva-
tive values could be used. Any alpha factor testing should
include results for fouled or dirty diffusers as well as
results for the new, clean diffusers.
For plug-flow systems where diffuser tapering is required to
match changing oxygen demand, both clean water transfer ef-
ficiency and alpha factor value selection must take into con-
sideration the need to select different values for SOTE and
alpha at different points along the taper.
In many fine pore aeration systems oxygen transfer efficiency
will diminish from a high value immediately after cleaning to
lower values as operating time increases. These changes in
oxygen transfer efficiency should be taken into consideration
for determining cleaning frequency and assessing overall
operating cost.
7.7 CLOGGING POTENTIAL
Regardless of operating mode, fine pore diffusers may clog or
foul over time. Both operating mode and wastewater charac-
teristics effect the degree and frequency of clogging. Fine
silt and other inorganic materials carried in the primary ef-
fluent stream can and do end up on the diffusers, causing an
increase in diffuser headloss. Biological materials which
develop on the surface of the diffusers also cause clogging
problems to exist. At Hartford, the high concentration of
soluble BOD in the primary effluent probably causes rapid
biofouling at the inlet ends of the aeration passes.
Air-side fouling can occur from particles in the air supply or
from backflow of mixed liquor into the diffuser grid piping
through leaking gaskets and bolts, broken bolts, and leaks in
the air piping. The major air-side fouling potential is from
leaks in equipment components and not from particles in the
air supply.
102
-------
7 .8 MECHANICAL RELIABILITY
Mechanical reliability is always a concern when using plastic
components in severe duty applications such as aeration.
Materials must be handled more carefully during installation.
Temperature variations must be accounted for with the thermal
expansion and contraction of the plastic components.
Diffuser attachment to the pipe grid system should be simple
and positive. Plastic dome bolts should not be used because
of high potential for bolt failure. Gaskets should be
manufactured of materials which will have long service life
and not leak shortly after installation. Gaskets can be re-
placed as required and plastic bolts can be replaced with
stainless steel bolts. However, replacement and repair of the
diffuser attachment is costly.
7.9 OVERALL ADVANTAGES AND DISADVANTAGES
The most significant advantage of any fine pore retrofit is
increased oxygen transfer efficiency. In some cases the in-
creased efficiency allows for reduction of power consumption,
and in other cases, additional aeration capacity is achieved
without additional power consumption.
The disadvantages of fine pore aeration are not significant as
long as the overall objectives of power savings or additional
aeration capacity are being achieved. These disadvantages in-
clude:
1. need for higher level of maintenance of the aeration
equipment,
2. shorter equipment life-cycle,
3. more limited tank accessibility for cleaning, and
4. possibility of tank downtime effecting process and
plant effluent quality.
In spite of higher levels of maintenance and operational care,
fine pore aeration retrofit systems which are properly
operated and maintained will have life-cycle costs which are
significantly less than continuing with the existing coarse
bubble equipment.
103
-------
8.0 REFERENCES
1. Manual of Methods for Fine Bubble Diffused Aeration Field
Studies, ASCE/EPA Project, July 1985.
2. "Coarse Bubble to Fine Bubble Aeration Retrofit," Paul F.
Gilbedrt and James H. Chase, Presented at the Ninth
U.S.-Japan Conference on Sewage Treatment Technology,
Tokyo, Japan, Sept. 1983.
3. "Report to the Metropolitan District Hartford, CT on
Cost-Effectiveness Analysis of Using Fine Bubble Dif-
fusers at Hartford WPCP," Metcalf & Eddy, Sept. 1981
4. "Report to Hartford, CT Metropolitan District Commission
on Evaluation of New Variable Speed Drives for the
Primary Effluent Pumps and New Blowers for the Aeration
System," Metcalf & Eddy, Jan. 1986.
104
-------
APPENDIX I—A
SUMMARY OF
INDIVIDUAL OFF-GAS FIELD TESTS
AND COMPUTATIONS FOR
AIRFLOW-WEIGHT AVERAGING
105
-------
OFF-GAS TEST RESULTS FOR SEPTEMBER 14, 1985
ML
TOTAL
ALPHA X
TEST
PASS
RUN
MEAS.
DO,
TEMP,
ALPHA X
NO. OF
AIRFLOW
AIRFLOW,
NEU
APPARENT
SOTR,
NEW
SOTR,
LOCATION
NO.
DATE
TIME
NO.
OTE.X
MG/L
DEG C
SOTE, X
DOMES
SCFM
SCFM
SOTE, X
ALPHA
LBS. 02/HR
LBS.
02/HR
1 -E
1
9-14-85
1400
1
8.88
0.20
25.3
8.94
223
1.00
223.0
28.2
0.32
20.66
65.17
1-E
1
9-14-85
1430
2
7.87
0.20
25.3
7.92
223
1.00
223.0
28.2
0.28
18.30
65.17
1-E
1
9-14-85
1445
3
8.33
0.20
25.3
8.39
223
1.00
223.0
28.2
0.30
19.39
65.17
1-E
AVG.
.
.
.
.
.
25.3
8.42
223
1.00
223.0
28.2
0.30
19.45
65.17
2-1
2
9-14-85
1530
4
5.37
0.20
25.2
5.41
338
0.70
236.6
30.1
0.18
13.26
73.80
2-1
2
9-14-85
1600
5
5.19
0.20
25.2
5.23
338
0.70
236.6
30.1
0.17
12.82
73.80
2-1
2
9-14-85
1730
6
6.95
0.20
25.2
7.00
338
0.70
236.6
30.1
0.23
17.16
73.80
2-1 AVG.
-
.
.
.
.
25.2
5.88
338
0.70
236.6
30.1
0.20
14.41
73.80
-------
OFF-GAS TEST RESULTS FOR NOVEMBER 12, 13 & 14, 1985
ML TOTAL ALPHA X
TEST
PASS
RUN
ME AS.
DO.
TEMP,
ALPHA X
NO. OF
AIRFLOW
AIRFLOW,
NEU
APPARENT
SOTR,
LOCATION
NO.
DATE
TIME
NO.
OTE,%
MG/L
DEG C
SOTE, %
DOMES
SCFM
SCFM
SOTE, X
ALPHA
LBS. 02/HR
2-1
2
11-13-85
1359
21
14.15
0.19
19.0
14.59
338
0.70
236.6
31.0
0.47
35.77
2-1
2
11-13-85
1415
22
14.35
0.18
18.8
14.80
338
0.70
236.6
31.0
0.48
36.29
2-1
2
11-13-85
1430
23
13.33
0.19
19.0
13.75
338
0.70
236.6
31.0
0.44
33.71
2-1
2
11-13-85
1445
24
13.37
0.19
19.0
13.79
338
0.70
236.6
31.0
0.44
33.81
2-1
AVG.
.
-
-
-
.
19.0
14.23
338
0.70
236.6
31.0
0.46
34.90
NEU SOTR,
LBS. 02/HR
76.01
76.01
76.01
76.01
76.01
!->
O
2-M
2
11-13-85
1300
17
15.23
0.13
18.8
15.63
245
0.40
98.0
30.3
0.52
15.87
2-M
2
11-13-85
1315
18
16.34
0.13
18.8
16.77
245
0.40
98.0
30.3
0.55
17.03
2-M
2
11-13-85
1330
19
16.37
0.14
18.7
16.82
245
0.40
98.0
30.3
0.56
17.08
2-M
2
11-13-85
1345
20
15.81
0.14
18.7
16.24
245
0.40
98.0
30.3
0.54
16.49
2-M AVG.
.
_
.
.
.
18.8
16.37
245
0.40
98.0
30.3
0.54
16.62
30.77
30.77
30.77
30.77
30.77
2-E
2
11-13-85
1159
13
13.05
0.15
18.5
13.43
210
0.40
84.0
30.3
0.44
11.69
2-E
2
11-13-85
1215
14
12.75
0.15
18.5
13.12
210
0.40
84.0
30.3
0.43
11.42
2-E
2
11-13-85
1230
15
13.14
0.13
18.6
13.49
210
0.40
84.0
30.3
0.45
11.74
2-E
2
11-13-85
1245
16
14.92
0.13
18.6
15.32
210
0.40
84.0
30.3
0.51
13.34
2-E AVG.
.
.
.
.
.
18.6
13.84
210
0.40
84.0
30.3
0.46
12.05
26.38
26.38
26.38
26.38
26.38
PASS 2 SUMMARY - .... 18>8 u.65 793 0.53 418.6 30.7 0.48 63.56 133.16
-------
OFF-GAS TEST RESULTS FOR OCTOBER 21, 1985
ML
TOTAL
ALPHA X
TEST *
PASS
RUN
HE AS.
DO,
TEMP,
ALPHA X
NO. OF
AIRFLOW
AIRFLOW,
NEW
APPARENT
SOTR,
NEW SOTR,
LOCATION
NO.
DATE
TIME
NO.
0TE,X
MG/L
DEG C
SOTE, X
DOMES
SCFM
SCFM
SOTE, X
ALPHA
LBS. 02/HR
LBS. 02/HR
1-E
1
10-21-85
1145
1
4.82
0.10
21.3
4.89
223
1.00
223.0
28.2
0.17
11.30
65.17
1-E
1
10-21-85
1230
2
4.94
0.10
21.3
5.01
223
1.00
223.0
28.2
0.18
11.58
65.17
1-E
1
10-21-85
1300
3
5.06
0.10
21.3
5.14
223
1.00
223.0
28.2
0.18
11.88
65.17
1-E
1
10-21-85
1430
4
5.39
0.10
21.3
5.47
223
1.00
223.0
28.2
0.19
12.64
65.17
I-1
1-E
1
10-21-85
1530
5
4.26
0.10
21.3
4.32
223
1.00
223.0
28.2
0.15
9.98
65.17
V >
<1
1-E
AVG.
-
-
-
-
-
21.3
4.97
223
1.00
223
28.2
0.18
11.48
65.17
* ALL TESTS CONDUCTED IN AERATION TANK NO. 1.
-------
OFF-GAS TEST RESULTS FOR NOVEMBER 12, 13 & 14, 198S
O
00
ML
TOTAL
ALPHA X
TEST
PASS
RUN
MEAS.
DO,
TEMP,
ALPHA X
NO. OF
AIRFLOW
AIRFLOW,
NEW
APPARENT
SOTR,
NEW
LOCATION
NO.
DATE
TIME
NO.
0TE,X
MG/L
DEG C
SOTE, X
DOMES
SCFM
SCFM
SOTE, X
ALPHA
LBS. 02/HR
LBS.
1-1
1
11-13-85
1001
9
10.25
2.20
18.2
13.04
489
0.50
244.5
33.5
0.39
33.04
1-1
1
11-13-85
1015
10
9.56
2.20
18.2
12.16
489
0.50
244.5
33.5
0.36
30.81
1-1
1
11-13-85
1030
11
9.31
2.20
18.3
11.84
489
0.50
244.5
33.5
0.35
30.00
1-1
1
11-13-85
1045
12
10.87
2.20
18.3
13.83
489
0.50
244.5
33.5
0.41
35.04
1-1
AVG.
-
-
-
-
-
18.3
12.72
489
0.50
244.5
33.5
0.38
32.22
1-M
1
11-12-85
1515
5
9.21
5.50
17.1
18.47
352
0.71
249.9
31.5
0.59
47.83
1-M
1
11-12-85
1545
6
11.62
5.40
17.1
22.90
352
0.71
249.9
31.5
0.73
59.31
1-M
1
11-13-85
1059
7
11.12
2.20
18.3
14.15
352
0.50
176.0
32.5
0.44
25.81
1-M
1
11-13-85
1115
8
13.70
2.20
18.3
17.43
352
0.50
176.0
32.5
0.54
31.79
1-M
AVG.
-
-
-
-
-
17.7
18.66
352
0.61
213.0
31.9
0.58
41.19
1-E
1
11-12-85
1330
1
15.28
1.40
17.7
17.80
223
0.71
158.3
29.0
0.61
29.20
1-E
1
11-12-85
1400
2
12.70
1.40
17.7
14.80
223
0.71
158.3
29.0
0.51
24.28
1-E
1
11-12-85
1430
3
16.35
1.70
17.3
19.66
223
0.71
158.3
29.0
0.68
32.26
1-E
1
11-12-85
1445
4
11.96
2.30
17.3
15.35
223
0.71
158.3
29.0
0.53
25.19
1-E
AVG.
.
.
.
-
.
17.5
16.90
223
0.71
158.3
29.0
0.58
27.73
84.88
84.88
84.88
84.88
84.88
81.58
81.58
59.27
59.27
70.43
47.58
47.58
47.58
47.58
47.58
PASS 1 SUMMARY - .... 17.8 15.85 1064 0.58 615.8 31.8 0.50 101.14 202.89
-------
OFF-GAS TEST RESULTS FOR NOVEMBER 12, 13 & 14, 1985
ML TOTAL ALPHA X
TEST
PASS
RUN
ME AS.
DO,
TEMP,
ALPHA X
NO. OF
AIRFLOW
AIRFLOW,
NEW
APPARENT
SOTR,
LOCATION
NO.
DATE
TIME
NO.
OTE,X
MG/L
DEG C
SOTE, X
DOMES
SCFM
SCFM
SOTE, X
ALPHA
LBS. 02/HR
3-1
3
11-14-85
1255
33
9.49
0.62
19.7
10.19
325
1.80
585.0
27.2
0.37
61.77
3-1
3
11-14-85
1315
34
10.97
0.62
19.7
11.78
325
1.80
585.0
27.2
0.43
71.41
3-1
3
11-14-85
1330
35
8.14
0.20
19.8
8.39
325
1.80
585.0
27.2
0.31
50.86
3-1
3
11-14-85
1345
36
8.54
0.20
19.8
8.80
325
1.80
585.0
27.2
0.32
53.35
3-1
AVG.
.
.
.
-
.
19.8
9.79
325
1.80
585.0
27.2
0.36
59.35
NEW SOTR,
LBS. 02/HR
164.89
164.89
164.89
164.89
164.89
V-1
,o
3-M
3
11-13-85
1615
29
13.55
0.19
19.1
13.97
245
0.90
220.5
28.9
3-M
3
11-13-85
1630
30
13.36
0.19
19.1
13.78
245
0.90
220.5
28.9
3-M
3
11-13-85
1645
31
13.30
0.15
19.3
13.65
245
0.90
220.5
28.9
3-M
3
11-13-85
1715
32
13.23
0.15
19.3
13.58
245
0.90
220.5
28.9
3-M AVG.
.
_
.
.
.
19.2
13.75
245
0.90
220.5
28.9
0.48
0.48
0.47
0.47
0.48
31.92
31.49
31.19
31.03
31.41
66.04
66.04
66.04
66.04
66.04
3-E
3
11-13-85
1500
25
15.99
0.19
19.0
16.49
223
0.90
200.7
28.9
0.57
34.30
3-E
3
11-13-85
1535
26
17.30
0.19
19.0
17.84
223
0.90
200.7
28.9
0.62
37.10
3-E
3
11-13-85
1540
27
16.48
0.19
19.1
16.99
223
0.90
200.7
28.9
0.59
35.34
3-E
3
11-13-85
1555
28
17.08
0.19
19.1
17.61
223
0.90
200.7
28.9
0.61
36.63
3-E AVG.
.
.
.
-
-
19.1
17.23
223
0.90
200.7
28.9
0.60
35.84
60.11
60.11
60.11
60.11
60.11
PASS 3 SUMMARY - .... 19.3 12.u 793 1.27 1QQ6.2 27.9 0.43 126.60 291.04
-------
OFF-GAS TEST RESULTS FOR NOVEMBER 12, 13 & 14, 1985
ML
TOTAL
ALPHA X
TEST
PASS
RUN
MEAS.
DO,
TEMP,
ALPHA X
NO. OF
AIRFLOW
AIRFLOW,
NEW
APPARENT
SOTR,
NEW SOTR,
LOCATION
NO.
DATE
TIME
NO.
OTE,X
MG/L
DEG C
SOTE, X
DOMES
SCFM
SCFM
SOTE, X
ALPHA
LBS. 0 /HR
LBS. 0 /HR
4-1
4
11-14-85
1610
45
8.29
0.11
19.7
8.47
293
1.70
498.1
26.8
0.32
43.72
138.33
4-1
4
11-14-85
1625
46
7.44
0.11
19.7
7.60
293
1.70
498.1
26.8
0.28
39.23
138.33
4-1
4
11-14-85
1640
47
8.12
0.11
19.7
8.30
293
1.70
498.1
26.8
0.31
42.84
138.33
4-1
4
11-14-85
1655
48
7.74
0.11
19.7
7.91
293
1.70
498.1
26.8
0.30
40.83
138.33
4-1
AVG.
-
-
-
-
-
19.7
8.07
293
1.70
498.1
26.8
0.30
41.66
138.33
4-M
4
11-14-85
1510
41
11.90
0.25
19.7
12.32
210
1.70
357.0
25.4
0.49
45.58
93.97
4-M
4
11-14-85
1525
42
12.37
0.25
19.7
12.81
210
1.70
357.0
25.4
0.50
47.39
93.97
I—1
4-M
4
11-14-85
1540
43
11.72
0.25
19.7
12.13
210
1.70
357.0
25.4
0.48
44.87
93.97
l-»
(—1
4-M
4
11-14-85
1555
44
11.83
0.25
19.7
12.25
210
1.70
357.0
25.4
0.48
45.32
93.97
4-M
AVG.
-
-
-
-
-
19.7
12.38
210
1.70
357.0
25.4
0.49
45.79
93.97
4-E
4
11-14-85
1410
37
11.69
0.54
19.6
12.46
176
1.70
299.2
23.5
0.53
38.63
72.86
4-E
4
11-14-85
1425
38
11.26
0.54
19.6
12.00
176
1.70
299.2
23.5
0.51
37.21
72.86
4-E
4
11-14-85
1440
39
12.24
0.21
19.6
12.63
176
1.70
299.2
23.5
0.54
39.16
72.86
4-E
4
11-14-85
1455
40
12.23
0.21
19.6
12.62
176
1.70
299.2
23.5
0.54
39.13
72.86
4-E
AVG.
-
-
-
-
-
19.6
12.43
176
1.70
299.2
23.5
0.53
38.53
72.86
PASS 4
SUMMARY
19.7
10.53
679
1.70
1154.3
25.5
0.41
125.98
305.16
-------
OFF-GAS TEST RESULTS FOR DECEMBER 19 AND 20, 1985
ML
TOTAL
ALPHA X
H1
to
TEST
PASS
RUN
ME AS.
DO,
TEMP,
ALPHA X
NO. OF
AIRFLOW
AIRFLOW,
NEW
APPARENT
SOTR,
ATI ON
NO.
DATE
TIME
NO.
OTE.X
MG/L
DEG C
SOTE, X
DOMES
SCFM
SCFM
SOTE, X
ALPHA
LBS. 02/HR
4-1
4
12-19-85
1415
1
5.87
0.33
16.1
6.18
293
1.75
512.8
26.8
0.23
32.84
4-1
4
12-19-85
1430
2
7.60
0.33
16.1
8.00
293
1.75
512.8
26.8
0.30
42.51
4-1
4
12-19-85
1440
3
6.48
0.20
16.2
6.74
293
1.75
512.8
26.8
0.25
35.81
4-1
4
12-19-85
1515
4
5.45
0.20
16.2
5.67
293
1.75
512.8
26.8
0.21
30.13
4-1
AVG.
-
-
-
-
-
16.2
6.65
293
1.75
512.8
26.8
0.25
35.32
2-1
2
12-19-85
1540
5
4.58
0.07
16.2
4.71
338
1.40
473.2
26.5
0.18
23.10
2-1
2
12-19-85
1600
6
4.10
0.07
16.2
4.22
338
1.40
473.2
26.5
0.16
20.69
2-1
2
12-19-85
1630
7
4.05
0.07
16.2
4.17
338
1.40
473.2
26.5
0.16
20.45
2-1
2
12-19-85
1710
8
5.14
0.07
16.2
5.29
338
1.40
473.2
26.5
0.20
25.94
2-1
AVG.
-
-
-
-
-
16.2
4.60
338
1.40
473.2
26.5
0.17
22.55
1-1
1
12-20-85
805
9
5.61
2.48
16.2
7.33
489
1.30
635.7
30.5
0.24
48.29
1-1
1
12-20-85
830
10
7.32
2.48
16.4
9.57
489
1.30
635.7
30.5
0.31
63.04
1-1
1
12-20-85
850
11
5.76
2.41
16.4
7.47
489
1.30
635.7
30.5
0.24
49.21
1-1
1
12-20-85
915
12
6.29
2.41
16.4
8.16
489
1.30
635.7
30.5
0.27
53.75
1-1
AVG.
-
-
-
-
-
16.4
8.13
489
1.30
635.7
30.5
0.27
53.57
3-1
3
12-20-85
945
13
7.19
0.54
16.1
7.72
325
1.60
520.0
27.5
0.28
41.60
3-1
3
12-20-85
1015
14
6.51
0.54
16.1
6.99
325
1.60
520.0
27.5
0.25
37.67
3-1
3
12-20-85
1050
15
7.82
0.39
16.1
8.28
325
1.60
520.0
27.5
0.30
44.62
3-1
3
12-20-85
1130
16
7.85
39
16.1
8.31
325
1.60
520.0
27.5
0.30
44.78
3-1
AVG.
-
.
-
-
.
16.1
7.83
325
1.60
520.0
27.5
0.28
42.17
NEW SOTR,
LBS. 02/HR
142.40
142.40
142.40
142.40
142.40
129.95
129.95
129.95
129.95
129.95
200.92
200.92
200.92
200.92
200.92
148.19
148.19
148.19
148.19
148.19
-------
OFF-GAS TEST RESULTS FOR MARCH 24 AND 25, 1986
ML
TOTAL
ALPHA X
TEST
PASS
RUN
MEAS.
DO,
TEMP,
ALPHA X
NO. OF
AIRFLOW
AIRFLOW,
NEW
APPARENT
SOTR,
NEW SOTR,
LOCATION
NO.
DATE
TIME
NO.
OTE.X
MG/L
DEG C
SOTE, X
DOMES
SCFM
SCFM
SOTE, X
ALPHA
LBS. 02/HR
LBS. 02/HR
1-1
1
3-24-86
1230
9
8.11
0.15
13.7
8.44
489
1.10
537.9
31.5
0.27
47.05
175.58
1-1
1
3-24-86
1245
10
8.26
0.15
13.7
8.59
489
1.10
537.9
31.5
0.27
47.88
175.58
1-1
1
3-24-86
1300
11
9.70
0.11
13.7
10.06
489
1.10
537.9
31.5
0.32
56.08
175.58
1-1
1
3-24-86
1315
12
8.30
0.11
13.7
8.60
489
1.10
537.9
31.5
0.27
47.94
175.58
1-1
AVG.
-
-
-
-
-
13.7
8.92
489
1.10
537.9
31.5
0.28
49.73
175.58
H1
1-M
1
3-24-86
1130
5
7.81
0.08
13.6
8.08
352
1.10
387.2
30.1
0.27
32.42
120.77
1—1
1-M
1
3-24-86
1145
6
7.79
0.08
13.6
8.06
352
1.10
387.2
30.1
0.27
32.34
120.77
UJ
1-M
1
3-24-86
1200
7
7.47
0.08
13.6
7.73
352
1.10
387.2
30.1
0.26
31.02
120.77
1-M
1
3-24-86
1215
8
7.70
0.08
13.6
7.96
352
1.10
387.2
30.1
0.26
31.94
120.77
1-M
AVG.
-
-
-
-
-
13.6
7.96
352
1.10
387.2
30.1
0.26
31.93
120.77
1-E
1
3-24-86
1030
1
9.10
0.11
13.4
9.44
223
1.10
245.3
28.1
0.34
24.00
71.43
1-E
1
3-24-86
1045
2
8.23
0.11
13.4
8.54
223
1.10
245.3
28.1
0.30
21.71
71.43
1-E
1
3-24-86
1100
3
8.12
0.09
13.5
8.41
223
1.10
245.3
28.1
0.30
21.38
71.43
1-E
1
3-24-86
1115
4
7.13
0.09
13.5
7.38
223
1.10
245.3
28.1
0.26
18.76
71.43
1-E
AVG.
-
-
-
-
-
13.5
8.44
223
1.10
245.3
28.1
0.30
21.46
71.43
PASS 1
SUMMARY
13.6
8.50
1064
1.10
1170.4
30.3
0.28
103.12
367.78
-------
OFF-GAS TEST RESULTS FOR MARCH 24 AND 25, 1986
HL
TOTAL
ALPHA X
TEST
PASS
RUN
MEAS.
DO,
TEMP,
ALPHA X
NO. OF
AIRFLOW
AIRFLOW,
NEW
APPARENT
SOTR,
NEW SOTR,
LOCATION
NO.
DATE
TIME
NO.
OTE.X
MG/L
DEG C
SOTE, X
DOMES
SCFM
SCFM
SOTE, X
ALPHA
LBS. 02/HR
LBS. 02/HR
2-1
2
3-24-86
1615
21
8.31
0.07
13.8
8.58
338
1.80
608.4
27.1
0.32
54.09
170.86
2-1
2
3-24-86
1630
22
7.91
0.07
13.8
8.17
338
1.80
608.4
27.1
0.30
51.51
170.86
2-1
2
3-24-86
1645
23
7.81
0.07
13.8
8.07
338
1.80
608.4
27.1
0.30
50.88
170.86
2-1
2
3-24-86
1730
24
8.85
0.07
13.8
9.14
338
1.80
608.4
27.1
0.34
57.62
170.86
2-1
AVG.
-
-
-
-
-
13.8
8.49
338
1.80
608.4
27.1
0.31
53.53
170.86
H1
2-M
2
3-24-86
1430
17
6.94
0.07
13.8
7.17
245
1.10
269.5
28.3
0.25
20.02
79.03
h-1
2-M
2
3-24-86
1445
18
7.98
0.07
13.8
8.24
245
1.10
269.5
28.3
0.29
23.01
79.03
it*
2-M
2
3-24-86
1500
19
6.64
0.07
13.8
6.86
245
1.10
269.5
28.3
0.24
19.16
79.03
2-M
2
3-24-86
1530
20
7.39
0.07
13.8
7.63
245
1.10
269.5
28.3
0.27
21.31
79.03
2-M AVG.
-
-
-
-
-
13.8
7.48
245
1.10
269.5
28.3
0.26
20.88
79.03
2-E
2
3-24-86
1330
13
7.78
0.14
13.7
8.09
210
1.10
231.0
28.1
0.29
19.37
67.27
2-E
2
3-24-86
1345
14
7.29
0.14
13.7
7.58
210
1.10
231.0
28.1
0.27
18.14
67.27
2-E
2
3-24-86
1400
15
7.01
0.14
13.7
7.29
210
1.10
231.0
28.1
0.26
17.45
67.27
2-E
2
3-24-86
1415
16
7.22
0.14
13.7
7.50
210
1.10
231.0
28.1
0.27
17.95
67.27
2-E
>
<
a
-
-
-
~
-
13.7
7.62
210
1.10
231.0
28.1
0.27
18.23
67.27
PASS 2
SUMMARY
13.8
8.06
793
1.40
1108.9
27.6
0.29
92.64
317.16
-------
OFF-GAS TEST RESULTS FOR MARCH 24 AND 25, 1986
ML
TOTAL
ALPHA X
TEST
PASS
RUN
ME AS.
DO.
TEMP,
ALPHA X
NO. OF
AIRFLOW
AIRFLOW,
NEW
APPARENT
SOTR,
NEW SOTR,
LOCATION
NO.
DATE
TIME
NO.
OTE,X
MG/L
DEG C
SOTE, X
DOMES
SCFM
SCFM
SOTE, X
ALPHA
LBS. 02/HR
LBS. 02/HR
3-!
3
3-25-86
1200
33
6.59
0.03
14.1
6.78
325
1.30
422.5
28.5
0.24
29.68
124.78
3-1
3
3-25-86
1245
34
6.61
0.03
14.1
6.80
325
1.30
422.5
28.5
0.24
29.77
124.78
3-1
3
3-25-86
1300
35
7.69
0.03
14.1
7.91
325
1.30
422.5
28.5
0.28
34.63
124.78
3-1
3
3-25-86
1315
36
7.04
0.03
14.1
7.25
325
1.30
422.5
28.5
0.25
31.74
124.78
3-1
AVG.
-
-
-
-
-
14.1
7.19
325
1.30
422.5
28.5
0.25
31.46
124.78
h->
3-M
3
3-25-86
1045
29
7.73
0.04
14.0
7.96
245
1.30
318.5
27.6
0.29
26.27
91.09
H1
3-M
3
3-25-86
1100
30
8.37
0.04
14.0
8.62
245
1.30
318.5
27.6
0.31
28.45
91.09
U1
3-M
3
3-25-86
1115
31
7.07
0.04
14.0
7.28
245
1.30
318.5
27.6
0.26
24.03
91.09
3-M
3
3-25-86
1130
32
6.96
0.04
14.0
7.17
245
1.30
318.5
27.6
0.26
23.66
91.09
3-M
>
<
e>
-
-
-
-
-
14.0
7.76
245
1.30
318.5
27.6
0.28
25.60
91.09
3-E
3
3-25-86
915
25
9.04
0.07
14.0
9.34
223
1.30
289.9
27.1
0.34
28.06
81.41
3-E
3
3-25-86
945
26
10.18
0.07
14.0
10.51
223
1.30
289.9
27.1
0.39
31.57
81.41
3-E
3
3-25-86
1000
27
9.01
0.07
14.0
9.31
223
1.30
289.9
27.1
0.34
27.97
81.41
3-E
3
3-25-86
1030
28
8.54
0.07
14.0
8.82
223
1.30
289.9
27.1
0.33
26.50
81.41
3-E
AVG.
-
-
~
-
14.0
9.50
223
1.30
289.9
27.1
0.35
28.53
81.41
PASS 3
SUMMARY
14.0
8.01
793
1.30
1030.9
27.8
0.29
85.60
297.28
-------
OFF-GAS TEST RESULTS FOR MARCH 24 AND 25, 1986
ML TOTAL ALPHA X
TEST PASS
RUN
MEAS.
DO,
TEMP,
ALPHA X
NO. OF
AIRFLOW
AIRFLOW,
NEW
APPARENT
SOTR,
LOCATION NO.
DATE
TIME
NO.
OTE.X
MG/L
DEG C
SOTE, X
DOMES
SCFM
SCFM
SOTE, X
ALPHA
LBS. 02/HR
4-1 4
3-25-86
1630
45
7.83
0.09
14.4
8.10
293
1.40
410.2
28.1
0.29
34.43
4-! 4
3-25-86
1645
46
7.60
0.09
14.4
7.86
293
1.40
410.2
28.1
0.28
33.41
4-1 4
3-25-86
1700
47
7.78
0.07
14.4
8.03
293
1.40
410.2
28.1
0.29
34.13
4-1 4
3-25-86
1730
48
7.82
0.07
14.4
8.07
293
1.40
410.2
28.1
0.29
34.30
4-1 AVG.
.
-
.
.
-
14.4
8.02
293
1.40
410.2
28.1
0.29
34.07
NEW SOTR,
LBS. 02/HR
119.45
119.45
119.45
119.45
119.45
CTi
4-M
4
3-25-86
1445
41
8.25
0.08
14.3
8.52
210
1.40
294.0
26.5
0.32
25.96
4-M
4
3-25-86
1515
42
7.44
0.08
14.3
7.69
210
1.40
294.0
26.5
0.29
23.43
4-M
4
3-25-86
1530
43
9.24
0.08
14.3
9.55
210
1.40
294.0
26.5
0.36
29.10
4-M
4
3-25-86
1600
44
8.69
0.08
14.3
8.98
210
1.40
294.0
26.5
0.34
27.36
4-M AVG.
-
.
-
.
-
14.3
8.69
210
1.40
294.0
26.5
0.33
26.46
80.74
80.74
80.74
80.74
80.74
4-E
4
3-25-86
1345
37
7.59
0.12
14.2
7.87
176
1.40
246.4
25.5
0.31
20.10
4-E
4
3-25-86
1400
38
6.74
0.12
14.2
6.99
176
1.40
246.4
25.5
0.27
17.85
4-E
4
3-25-86
1415
39
7.24
0.12
14.2
7.51
176
1.40
246.4
25.5
0.29
19.18
4-E
4
3-25-86
1430
40
7.64
0.12
14.2
7.92
176
1.40
246.4
25.5
0.31
20.22
4-E AVG.
¦
-
.
.
.
14.2
7.57
176
1.40
246.4
25.5
0.30
19.34
65.11
65.11
65.11
65.11
65.11
PASS 4 SUMMARY - .... 14.3 8.11 679 1.40 950.6 26.9 0.30 79.87 265.30
-------
OFF-GAS TEST RESULTS FOR APRIL 1 AND 2, 1986 (DIURNAL STUOY)
ML
TOTAL
ALPHA X
TEST
PASS
RUN
ME AS.
DO.
TEMP,
ALPHA X
NO. OF
AIRFLOW
AIRFLOW,
NEW
APPARENT
SOTR,
NEW SOTR,
LOCATION
NO.
DATE
TIME
NO.
OTE,X
MG/L
DEG C
SOTE. X
DOMES
SCFM
SCFM
SOTE, X
ALPHA
LBS. 02/HR
LBS. 02/HR
2-M
2
4-1-86
1130
1
7.50
0.18
15.2
7.81
245
1.10
269.5
28.3
0.28
21.81
79.03
2-M
2
4-1-86
1145
2
8.45
0.18
15.2
8.80
245
1.10
269.5
28.3
0.31
24.58
79.03
2-M
2
4-1-86
1230
3
8.50
0.18
15.2
8.85
245
1.10
269.5
28.3
0.31
24.72
79.03
2-M
2
4-1-86
1245
4
7.96
0.14
15.1
8.26
245
1.10
269.5
28.3
0.29
23.07
79.03
2-M
2
4-1-86
1330
5
8.11
0.13
15.2
8.41
245
1.10
269.5
28.3
0.30
23.49
79.03
2-M
2
4-1-86
1345
6
7.76
0.13
15.2
8.04
245
1.10
269.5
28.3
0.28
22.45
79.03
2-M
2
4-1-86
1430
7
7.07
0.12
15.2
7.32
245
1.10
269.5
28.3
0.26
20.44
79.03
2-M
2
4-1-86
1445
8
7.77
0.12
15.2
8.05
245
1.10
269.5
28.3
0.28
22.48
79.03
2-M
2
4-1-86
1530
9
7.49
0.07
15.4
7.72
245
1.10
269.5
28.3
0.27
21.56
79.03
2-M
2
4-1-86
1545
10
8.40
0.07
15.4
8.66
245
1.10
269.5
28.3
0.31
24.19
79.03
2-M
2
4-1-86
1630
11
6.67
0.06
15.4
6.87
245
1.10
269.5
28.3
0.24
19.19
79.03
2-M
2
4-1-86
1645
12
7.27
0.06
15.4
7.49
245
1.10
269.5
28.3
0.26
20.92
79.03
2-M
2
4-1-86
1730
13
7.48
0.06
15.3
7.70
245
1.10
269.5
28.3
0.27
21.50
79.03
2-M
2
4-1-86
1745
14
6.83
0.06
15.3
7.04
245
1.10
269.5
28.3
0.25
19.66
79.03
2-M
2
4-1-86
1830
15
6.72
0.06
15.3
6.92
245
1.10
269.5
28.3
0.24
19.33
79.03
2-M
2
4-1-86
1845
16
7.05
0.06
15.3
7.26
245
1.10
269.5
28.3
0.26
20.28
79.03
2-M
2
4-1-86
1930
17
6.90
0.06
15.4
7.11
245
1.10
269.5
28.3
0.25
19.86
79.03
2-M
2
4-1-86
1945
18
6.24
0.06
15.4
6.43
245
1.10
269.5
28.3
0.23
17.96
79.03
2-M
2
4-1-86
2030
19
7.38
0.06
15.3
7.60
245
1.10
269.5
28.3
0.27
21.22
79.03
2-M
2
4-1-86
2045
20
7.76
0.06
15.3
7.99
245
1.10
269.5
28.3
0.28
22.31
79.03
2-M
2
4-1-86
2230
21
7.06
0.06
15.2
7.27
245
1.10
269.5
28.3
0.26
20.30
79.03
2-M
2
4-1-86
2245
22
7.33
0.06
15.2
7.55
245
1.10
269.5
28.3
0.27
21.09
79.03
2-M
2
4-2-86
0030
23
7.50
0.06
15.1
7.73
245
1.30
318.5
27.4
0.28
25.51
90.43
2-M
2
4-2-86
0045
24
7.45
0.06
15.1
7.68
245
1.30
318.5
27.4
0.28
25.35
90.43
2-M
2
4-2-86
0230
25
7.44
0.05
15.1
7.66
245
1.30
318.5
27.4
0.28
25.28
90.43
2-M
2
4-2-86
0245
26
7.39
0.05
15.1
7.61
245
1.30
318.5
27.4
0.28
25.12
90.43
2-M
2
4-2-86
0430
27
8.51
0.06
15.1
8.77
245
1.30
318.5
27.4
0.32
28.95
90.43
2-M
2
4-2-86
0445
28
8.19
0.06
15.1
8.44
245
1.30
318.5
27.4
0.31
27.86
90.43
2-M
2
4-2-86
0630
29
8.00
0.08
15.0
8.26
245
1.30
318.5
27.4
0.30
27.26
90.43
2-M
2
4-2-86
0645
30
7.88
0.08
15.0
8.14
245
1.30
318.5
27.4
0.30
26.87
90.43
2-M
2
4-2-86
0730
31
8.41
0.07
14.9
8.68
245
1.30
318.5
27.4
0.32
28.65
90.43
2-M
2
4-2-86
0745
32
8.65
0.07
14.9
8.93
245
1.30
318.5
27.4
0.33
29.47
90.43
2-M
2
4-2-86
0830
33
7.48
0.09
14.9
7.73
245
1.20
294.0
27.6
0.28
23.55
84.09
2-M
2
4-2-86
0845
34
8.59
0.09
14.9
8.88
245
1.20
294.0
27.6
0.32
27.05
84.09
2-M
2
4-2-86
0930
35
10.83
0.15
14.8
11.25
245
1.20
294.0
27.6
0.41
34.27
84.09
2-M
2
4-2-86
0945
36
9.02
0.15
14.8
9.37
245
1.20
294.0
27.6
0.34
28.55
84.09
2-M
2
4-2-86
1030
37
9.86
0.25
14.8
10.33
245
1.20
294.0
27.6
0.37
31.47
84.09
2-M
2
4-2-86
1045
38
10.67
0.25
14.8
11.18
245
1.20
294.0
27.6
0.41
34.06
84.09
2-M
2
4-2-86
1130
39
9.83
0.13
14.8
10.20
245
1.20
294.0
27.6
0.37
31.08
84.09
2-M
2
4-2-86
1145
40
9.49
0.13
14.8
9.84
245
1.20
294.0
27.6
0.36
29.98
84.09
2-M
AVG.
.
.
.
.
_
15.1
8.27
245
1.17
286.7
27.9
0.30
24.57
82.89
-------
OFF-GAS TEST RESULTS FOR
TEST
PASS
RUN
ME AS.
DO,
TEMP,
ALPHA X
OCATION
NO.
DATE
TIME
NO.
OTE,X
MG/L
DEG C
SOTE, X
1-1
1
7-14-86
1503
5
7.86
1.35
21.8
9.23
1-M
1
7-14-86
1423
3
8.57
0.85
21.7
9.44
1-E
1
7-14-86
1345
1
10.93
0.25
21.6
11.21
PASS 1
SUMMARY
-
-
-
-
-
21.7
9.71
2-1
2
7-14-86
1402
2
11.64
1.25
21.7
13.51
2-M
2
7-14-86
1435
4
10.90
0.35
21.0
11.42
2-E
2
7-14-86
1514
6
9.83
0.25
21.8
10.05
PASS 2
SUMMARY
-
-
-
-
-
21.5
11.95
3-1
3
7-14-86
1557
7
6.57
0.18
22.0
6.64
3-M
3
7-14-86
1615
9
7.62
0.18
22.2
7.72
3-E
3
7-14-86
1637
11
9.83
0.35
22.2
10.16
PASS 3
SUMMARY
-
-
-
-
-
22.1
7.96
4-1
4
7-14-86
1644
12
7.12
0.18
22.3
7.21
4-M
4
7-14-86
1625
10
7.71
0.20
22.2
7.83
4-E
4
7-14-86
1607
8
7.69
0.18
22.1
7.78
PASS 4
SUMMARY
-
-
-
-
-
22.2
7.55
TANK 2
SUMMARY
21.9
9.34
14 AND 15, 1986
NO. OF
DOMES
AIRFLOW
SCFM
TOTAL
AIRFLOW,
SCFM
NEW
SOTE, X
APPARENT
ALPHA
ALPHA X
SOTR,
LBS. 02/HR
489
352
223
2.10
2.10
2.10
1026.9
739.2
468.3
27.8
26.7
25.3
0.33
0.35
0.44
98.22
72.31
54.40
1064
2.10
2234.4
26.9
0.36
224.93
338
245
210
2.40
2.40
2.40
811.2
588.0
504.0
25.5
24.7
24.5
0.53
0.46
0.41
113.57
69.59
52.49
793
2.40
1903.2
25.0
0.48
235.64
325
245
223
2.50
2.50
2.50
812.5
612.5
557.5
25.5
24.7
24.5
0.26
0.31
0.41
55.91
49.00
58.70
793
2.50
1982.5
25.0
0.32
163.60
293
210
176
2.50
2.50
2.50
732.5
525.0
440.0
25.2
24.2
23.7
0.29
0.32
0.33
54.73
42.60
35.47
679
2.50
1697.5
24.5
0.31
132.80
3329
2.35
7817.6
25.4
0.37
756.98
NEW SOTR,
LBS. 02/HR
295.83
204.52
122.78
623.13
214.36
150.50
127.96
492.82
214.70
156.77
141.54
513.02
191.28
131.66
108.06
431.01
2059.98
-------
OFF-GAS TEST RESULTS FOR
ML
TEST
PASS
RUN
MEAS.
DO,
TEMP,
ALPHA X
LOCATION
NO.
DATE
TIME
NO.
OTE.X
MG/L
DEG C
SOTE, X
1-1
1
7-15-86
1237
20
8.62
0.70
22.6
9.33
1-M
1
7-15-86
1317
22
9.35
0.30
22.7
9.64
1-E
1
7-15-86
1408
24
9.21
0.10
22.9
9.28
PASS 1
SUMMARY
-
-
-
-
-
22.7
9.42
2-1
2
7-15-86
1358
23
9.62
0.40
23.0
10.06
2-M
2
7-15-86
1300
21
8.90
0.20
23.1
9.08
l->
2-E
2
7-15-86
1214
19
10.81
0.20
23.3
11.02
I-1
PASS 2
SUMMARY
23.1
10.01
3-1
3
7-15-86
1139
18
8.60
0.10
22.7
8.66
3-M
3
7-15-86
1105
16
11.57
0.50
22.6
12.21
3-E
3
7-15-86
1042
14
10.64
1.30
22.6
12.46
PASS 3
SUMMARY
-
-
-
-
-
22.6
10.83
4-1
4
7-15-86
1028
13
6.16
0.30
22.2
6.33
4-M
4
7-15-86
1054
15
8.03
0.80
22.3
8.78
4-E
4
7-15-86
1124
17
10.02
1.20
22.4
11.55
PASS 4
SUMMARY
-
-
-
-
-
22.3
8.44
TANK 2
SUMMARY
22.7
9.71
14 AND 15, 1986
). OF
lOMES
AIRFLOW
SCFM
TOTAL
AIRFLOW,
SCFM
NEW
SOTE, X
APPARENT
ALPHA
ALPHA X
SOTR,
LBS. 02/HR
NEW SOTR,
LBS. 02/HR
489
352
223
2.20
2.20
2.20
1075.8
774.4
490.6
27.8
26.7
25.3
0.34
0.36
0.37
104.01
77.36
47.18
309.92
214.26
128.62
1064
2.'20
2340.8
26.9
0.35
228.55
652.81
338
245
210
2.60
2.60
2.60
878.8
637.0
546.0
25.5
24.7
24.5
0.39
0.37
0.45
91.61
59.94
62.35
232.22
163.05
138.62
793
2.60
2061.8
25.0
0.40
213.90
533.89
325
245
223
2.50
2.50
2.50
812.5
612.5
557.5
25.5
24.7
24.5
0.34
0.49
0.51
72.91
77.50
71.98
214.70
156.77
141.54
793
2.50
1982.5
25.0
0.43
222.40
513.02
293
210
176
2.50
2.50
2.50
732.5
525.0
440.0
25.2
24.2
23.7
0.25
0.36
0.49
48.05
47.77
52.66
191.28
131.66
108.06
679
2.50
1697.5
24.5
0.34
148.48
431.01
3329
2.43
8082.6
25.4
0.38
813.33
2130.72
-------
OFF-GAS TEST RESULTS FOR JULY 14 AND 15, 1986
TEST
DCATION
PASS
NO.
DATE
TIME
RUN
NO.
ME AS.
OTE,X
DO,
MG/L
TEMP,
DEG C
ALPHA X
SOTE, X
NO. OF
DOMES
AIRFLOW
SCFM
AIRFLOW,
SCFM
NEW
SOTE, X
APPARENT
ALPHA
SOTR,
LBS. 02/HR
NEW SOTR,
LBS. 02/HR
1-1
1-M
1-E
1
1
1
7-15-86
7-15-86
7-15-86
1519
1451
1408
30
28
26
8.58
8.83
9.21
0.25
0.30
0.10
22.9
22.9
22.9
8.80
9.12
9.28
489
352
223
2.20
2.20
2.20
1075.8
774.4
490.6
27.8
26.7
25.3
0.32
0.34
0.37
98.10
73.19
47.18
309.92
214.26
128.62
PASS 1
SUMMARY
-
-
-
-
-
22.9
9.01
1064
2.20
2340.8
26.9
0.33
218.47
652.81
2-1
2-M
2-E
2
2
2
7-15-86
7-15-86
7-15-86
1358
1416
1504
25
27
29
9.62
11.15
13.27
0.40
0.20
0.15
23.0
23.1
23.1
10.06
11.38
13.46
338
245
210
2.60
2.60
2.60
878.8
637.0
546.0
25.5
24.7
24.5
0.39
0.46
0.55
91.61
75.12
76.16
232.22
163.05
138.62
PASS 2
SUMMARY
-
-
-
-
-
23.1
11.37
793
2.60
2061.8
25.0
0.45
242.89
533.89
3-1
3-M
3-E
3
3
3
7-15-86
7-15-86
7-15-86
1557
1616
1639
31
33
35
6.15
7.83
10.43
0.10
0.15
0.40
22.9
23.0
23.1
6.20
7.94
10.90
325
245
223
2.50
2.50
2.50
812.5
612.5
557.5
25.5
24.7
24.5
0.24
0.32
0.45
52.20
50.40
62.97
214.70
156.77
141.54
PASS 3
SUMMARY
-
-
-
-
-
23.0
8.06
793
2.50
1982.5
25.0
0.32
165.57
513.02
4-1
4-M
4-E
4
4
4
7-15-86
7-15-86
7-15-86
1653
1623
1610
36
34
32
8.57
6.02
8.50
0.10
0.10
0.20
23.0
22.9
22.9
8.64
6.07
8.67
293
210
176
2.50
2.50
2.50
732.5
525.0
440.0
25.2
24.2
23.7
0.34
0.25
0.37
65.58
33.02
39.53
191.28
131.66
108.06
PASS 4
SUMMARY
-
-
-
-
-
22.9
7.85
679
2.50
1697.5
24.5
0.32
138.14
431.01
TANK 2
SUMMARY
23.0
9.13
3329
2.43
8082.6
25.4
0.36
765.07
2130.72
-------
OFF-GAS TEST RESULTS FOR FEBRUARY 4 AND 5, 1987
TEST
SCAT ION
PASS
NO.
DATE
TIME
RUN
NO.
MEAS.
OTE,X
DO,
MG/L
ML
TEMP,
DEG C
ALPHA X
SOTE, X
NO. OF
DOMES
AIRFLOW
SCFM
TOTAL
AIRFLOW,
SCFM
NEW
SOTE, X
APPARENT
ALPHA
ALPHA X
SOTR,
LBS. 02/HR
NEW SOTR,
LBS. 02/HR
1-1
1-M
1-E
1
1
1
2-4-87
2-4-87
2-4-87
1515
1445
1420
5
3
1
6.70
5.27
9.44
3.44
3.08
0.18
13.4
13.3
13.3
10.32
7.71
9.87
489
352
223
1.50
1.50
1.50
733.5
528.0
334.5
29.5
28.2
26.3
0.35
• 0.27
0.38
78.44
42.19
34.21
224.23
154.30
91.16
PASS 1
SUMMARY
-
-
-
-
-
13.3
9.36
1064
1.50
1596.0
28.4
0.33
154.84
469.69
2-1
2-M
2-E
2
2
2
2-4-87
2-4-87
2-4-87
1430
1500
1545
2
4
6
8.59
7.37
6.61
0.37
0.18
0.13
13.3
13.3
13.4
9.16
7.71
6.88
338
245
210
1.40
1.40
1.40
473.2
343.0
294.0
28.0
26.9
26.7
0.33
0.29
0.26
44.92
27.40
20.96
137.30
95.61
81.35
PASS 2
SUMMARY
-
-
-
-
-
13.3
8.11
793
1.40
1110.2
27.3
0.30
93.28
314.26
3-1
3-M
3-E
3
3
3
2-4-87
2-4-87
2-4-87
1610
1650
1725
7
10
12
5.59
7.44
8.00
0.20
0.37
0.99
13.4
13.4
13.4
5.86
7.93
9.09
325
245
223
1.60
1.60
1.60
520.0
392.0
356.8
27.6
26.4
26.1
0.21
0.30
0.35
31.58
32.21
33.61
148.73
107.24
96.50
PASS 3
SUMMARY
-
-
-
-
-
13.4
7.41
793
1.60
1268.8
26.8
0.28
97.40
352.47
4-1
4-M
4-E
4
4
4
2-4-87
2-4-87
2-4-87
1715
1645
1630
11
9
8
4.85
6.44
6.75
0.94
1.11
1.82
13.4
13.4
13.4
5.48
7.41
8.42
293
210
176
1.70
1.70
1.70
498.1
357.0
299.2
26.8
25.5
24.9
0.20
0.29
0.34
28.29
27.41
26.11
138.33
94.34
77.20
PASS 4
SUMMARY
-
-
-
-
-
13.4
6.84
679
1.70
1154.3
25.9
0.26
81.81
309.87
TANK 2
SUMMARY
13.4
8.04
3329
1.54
5129.3
27.2
0.30
427.33
1446.29
-------
OFF-GAS TEST RESULTS FOR FEBRUARY 4 AND 5, 1987
TEST
XATION
PASS
NO.
DATE
TIME
RUN
NO.
ME AS.
OTE.X
DO,
MG/L
ML
TEMP,
DEG C
ALPHA X
SOTE, X
NO. OF
DOMES
AIRFLOW
SCFM
TOTAL
AIRFLOW,
SCFM
NEW
SOTE, X
APPARENT
ALPHA
ALPHA X
SOTR,
LBS. 02/HR
NEW SOTR,
LBS. 02/HR
1-1
1-M
1-E
1
1
1
2-5-87
2-5-87
2-5-87
1050
1115
1125
20
22
23
6.48
7.22
7.61
4.40
3.90
0.40
12.8
12.8
12.9
11.49
11.83
8.14
489
352
223
1.40
1.40
1.40
684.6
492.8
312.2
29.7
28.4
26.5
0.39
0.42
0.31
81.51
60.41
26.33
210.70
145.03
85.73
PASS 1
SUMMARY
-
-
-
-
-
12.8
10.90
1064
1.40
1489.6
28.6
0.38
168.26
441.47
2-1
2-M
2-E
2
2
2
2-5-87
2-5-87
2-5-87
1135
1100
1020
24
21
19
7.51
7.51
6.05
1.30
1.50
1.20
12.9
12.8
12.8
8.82
9.02
7.03
338
245
210
1.40
1.40
1.40
473.2
343.0
294.0
27.9
26.8
26.5
0.32
0.34
0.27
43.25
32.06
21.42
136.81
95.26
80.74
PASS 2
SUMMARY
-
-
-
-
-
12.8
8.41
793
1.40
1110.2
27.2
0.31
96.73
312.80
3-1
3-M
3-E
3
3
3
2-5-87
2-5-87
2-5-87
950
915
850
17
15
13
6.07
4.71
8.48
2.80
2.85
2.90
12.7
12.7
12.8
8.51
6.65
12.06
325
245
223
1.50
1.50
1.50
487.5
367.5
334.5
27.7
26.6
26.3
0.31
0.25
0.46
42.99
25.33
41.80
139.94
101.30
91.16
PASS 3
SUMMARY
-
-
-
-
-
12.7
8.93
793
1.50
1189.5
27.0
0.33
110.12
332.40
4-1
4-M
4-E
4
4
4
2-5-87
2-5-87
2-5-87
905
925
1005
14
16
18
6.74
7.54
4.69
4.30
4.90
5.00
12.7
12.6
12.6
11.74
14.51
9.19
293
210
176
1.70
1.70
1.70
498.1
357.0
299.2
26.8
25.5
24.9
0.44
0.57
0.37
60.60
53.68
28.49
138.33
94.34
77.20
PASS 4
SUMMARY
-
-
-
-
-
12.6
11.94
679
1.70
1154.3
25.9
0.46
142.77
309.87
TANK 2
SUMMARY
12.8
10.11
3329
1.49
4943.6
27.3
0.37
517.88
1396.54
-------
OFF-GAS TEST RESULTS FOR FEBRUARY 4 AND 5, 1987
TEST
XATION
PASS
NO.
DATE
TIME
RUN
NO.
MEAS.
0TE,X
DO,
MG/L
ML
TEMP,
DEG C
ALPHA X
SOTE, X
NO. OF
DOMES
AIRFLOW
SCFM
TOTAL
AIRFLOW,
SCFM
NEW
SOTE, X
APPARENT
ALPHA
ALPHA X
SOTR,
LBS. 02/HR
NEW SOTR,
LBS. 02/HR
1-1
1-M
1-E
1
1
1
2-5-87
2-5-87
2-5-87
1210
1150
1145
29
27
26
4.86
5.81
8.16
4.10
3.90
0.50
12.8
12.7
12.9
8.21
9.51
8.81
489
352
223
1.40
1.40
1.40
684.6
492.8
312.2
29.7
28.4
26.5
0.28
0.33
0.33
58.24
48.57
28.50
210.70
145.03
85.73
PASS 1
SUMMARY
-
-
-
-
-
12.8
8.77
1064
1.40
1489.6
28.6
0.31
135.31
441.47
2-1
2-M
2-E
2
2
2
2-5-87
2-5-87
2-5-87
1140
1200
1220
25
28
30
8.02
7.49
7.36
1.10
0.75
0.40
12.8
12.9
12.9
9.22
8.30
7.87
338
245
210
1.40
1.40
1.40
473.2
343.0
294.0
27.9
26.8
26.5
0.33
0.31
0.30
45.21
29.50
23.98
136.81
95.26
80.74
PASS 2
SUMMARY
-
-
-
-
-
12.9
8.58
793
1.40
1110.2
27.2
0.32
98.69
312.80
3-1
3-M
3-E
3
3
3
2-5-87
2-5-87
2-5-87
1305
1325
1345
32
34
35
7.38
7.87
10.96
0.93
0.80
1.40
13.1
13.1
13.1
8.33
8.77
13.02
325
245
223
1.30
1.30
1.30
422.5
318.5
289.9
28.5
27.1
27.1
0.29
0.32
0.48
36.47
28.95
39.11
124.78
89.44
81.41
PASS 3
SUMMARY
-
-
-
-
-
13.1
9.78
793
1.30
1030.9
27.7
0.35
104.53
295.64
4-1
4-H
4-E
4
4
4
2-5-87
2-5-87
2-5-87
1400
1320
1250
36
33
31
5.84
6.71
6.29
1.40
2.60
3.75
13.2
13.1
13.1
6.94
9.20
10.11
293
210
176
1.70
1.70
1.70
498.1
357.0
299.2
26.8
25.5
24.9
0.26
0.36
0.41
35.82
34.04
31.35
138.33
94.34
77.20
PASS 4
SUMMARY
-
-
-
-
-
13.1
8.46
679
1.70
1154.3
25.9
0.33
101.20
309.87
TANK 2
SUMMARY
13.0
8.87
3329
1.44
4785.0
27.4
0.32
439.74
1359.78
-------
OFF-GAS TEST RESULTS FOR APRIL 22 AND 23, 1987
TEST
3CAT10N
PASS
NO.
DATE
TIME
RUN
NO.
ME AS.
OTE,X
DO,
MG/L
ML
TEMP,
DEG C
ALPHA X
SOTE, X
NO. OF
DOMES
AIRFLOW
SCFM
TOTAL
AIRFLOW,
SCFM
NEW
SOTE, X
APPARENT
ALPHA
ALPHA X
SOTR,
LBS. 02/HR
NEW SOTR,
LBS. 02/HR
1-1
1-M
1-E
1
1
1
4-22-87
4-22-87
4-22-87
1405
1345
1250
5
3
1
9.03
12.01
11.86
1.50
1.10
0.20
15.1
15.0
14.9
10.63
13.60
12.38
489
352
223
1.28
1.28
1.28
625.9
450.6
285.4
31.0
29.2
27.3
0.34
0.47
0.45
68.95
63.50
36.62
201.07
136.34
80.75
PASS 1
SUMMARY
-
-
-
-
-
15.0
11.98
1064
1.28
1361.9
29.6
0.40
169.07
418.16
2-1
2-M
2-E
2
2
2
4-22-87
4-22-87
4-22-87
1330
1355
1410
2
4
6
9.33
9.93
10.35
0.50
0.25
0.30
15.0
15.1
15.1
10.00
10.40
10.89
338
245
210
1.08
1.08
1.08
365.0
264.6
226.8
29.9
28.7
28.3
0.33
0.36
0.38
37.83
28.52
25.59
113.11
78.69
66.51
PASS 2
SUMMARY
-
-
-
-
-
15.1
10.36
793
1.08
856.4
29.1
0.36
91.94
258.31
3-1
3-M
3-E
3
3
3
4-22-87
4-22-87
4-22-87
1445
1500
1520
8
10
12
8.39
8.42
12.11
0.30
0.30
0.60
15.2
15.2
15.2
8.83
8.86
13.09
325
245
223
1.28
1.28
1.28
416.0
313.6
285.4
28.9
27.7
27.3
0.31
0.32
0.48
38.07
28.79
38.72
124.58
90.02
80.75
PASS 3
SUMMARY
-
-
-
-
-
15.2
10.04
793
1.28
1015.0
28.1
0.36
105.58
295.35
4-1
4-M
4-E
4
4
4
4-22-87
4-22-87
4-22-87
1510
1450
1430
11
9
7
6.90
9.47
11.81
0.30
0.40
0.50
15.2
15.2
15.2
7.26
10.05
12.65
293
210
176
1.43
1.43
1.43
419.0
300.3
251.7
27.5
25.9
25.5
0.26
0.39
0.50
31.52
31.27
32.99
119.40
80.60
66.51
PASS 4
SUMMARY
-
-
-
-
-
15.2
9.52
679
1.43
971.0
26.5
0.36
95.79
266.51
TANK 2
SUMMARY
15.1
10.61
3329
1.26
4204.4
28.4
0.37
462.37
1238.33
-------
OFF-GAS TEST RESULTS FOR APRIL 22 AND 23, 1987
TEST
XATION
PASS
NO.
DATE
TIME
RUN
NO.
MEAS.
OTE,X
DO,
MG/L
ML
TEMP,
DEG C
ALPHA X
SOTE, X
NO. OF
DOMES
AIRFLOW
SCFM
TOTAL
AIRFLOW,
SCFM
NEW
SOTE, X
APPARENT
ALPHA
ALPHA X
SOTR,
LBS. 02/HR
NEW SOTR,
LBS. 02/HR
1-1
1-M
1-E
1
1
1
4-23-87
4-23-87
4-23-87
1140
1200
1215
20
22
24
7.28
7.38
9.67
3.80
3.75
0.35
14.5
14.5
14.7
11.01
11.09
10.22
489
352
223
1.45
1.45
1.45
709.1
510.4
323.4
26.3
28.2
26.3
0.42
0.39
0.39
80.90
58.66
34.24
193.24
149.15
88.13
PASS 1
SUMMARY
-
-
-
-
-
14.6
10.87
1064
1.45
1542.8
26.9
0.40
173.80
430.52
2-1
2-M
2-E
2
2
2
4-23-87
4-23-87
4-23-87
1210
1150
1130
23
21
19
8.68
7.46
8.35
0.60
0.65
0.65
14.5
14.6
14.5
9.38
8.10
9.07
338
245
210
1.41
1.41
1.41
476.6
345.5
296.1
27.7
26.6
26.3
0.34
0.30
0.34
46.32
29.00
27.83
136.80
95.22
80.70
PASS 2
SUMMARY
-
-
-
-
-
14.5
8.90
793
1.41
1118.1
27.0
0.33
103.15
312.72
3-1
3-M
3-E
3
3
3
4-23-87
4-23-87
4-23-87
1105
1030
1010
18
15
13
9.69
8.79
11.23
1.30
3.70
5.20
14.4
13.7
13.7
11.17
13.04
20.32
325
245
223
1.52
1.52
1.52
494.0
372.4
339.0
27.7
26.6
26.3
0.40
0.49
0.77
57.18
50.32
71.37
141.80
102.65
92.38
PASS 3
SUMMARY
-
-
-
-
-
13.9
14.32
793
1.52
1205.4
27.0
0.53
178.88
336.83
4-1
4-M
4-E
4
4
4
4-23-87
4-23-87
4-23-87
1020
1040
1100
14
16
17
7.92
8.00
9.76
4.50
4.20
4.00
13.7
13.9
14.5
13.00
12.65
15.14
293
210
176
1.59
1.59
1.59
465.9
333.9
279.8
27.5
25.9
25.2
0.47
0.49
0.60
62.76
43.77
43.90
132.76
89.62
73.08
PASS 4
SUMMARY
-
-
-
-
-
14.0
13.45
679
1.59
1079.6
26.4
0.51
150.43
295.45
TANK 2
SUMMARY
14.3
11.83
3329
1.49
4945.9
26.8
0.44
606.26
1375.53
-------
OFF-GAS TEST RESULTS FOR APRIL 22 AND 23, 1987
TEST
DCATION
PASS
NO.
DATE
TIME
RUN
NO.
ME AS.
OTE,X
DO,
MG/L
ML
TEMP,
DEG C
ALPHA X
SOTE, X
NO. OF
DOMES
AIRFLOW
SCFM
TOTAL
AIRFLOW,
SCFM
NEW
SOTE, X
APPARENT
ALPHA
ALPHA X
SOTR,
LBS. 02/HR
NEW SOTR,
LBS. 02/HR
1-1
1-M
1-E
1
1
1
4-23-87
4-23-87
4-23-87
1300
1240
1230
30
28
26
7.55
8.71
10.15
3.70
3.00
0.50
14.8
14.7
14.7
11.31
12.00
10.87
489
352
223
1.45
1.45
1.45
709.1
510.4
323.4
29.5
28.2
26.3
0.38
0.43
0.41
83.10
63.47
36.42
216.76
149.15
88.13
PASS 1
SUMMARY
-
-
-
-
-
14.7
11.45
1064
1.45
1542.8
28.4
0.40
182.99
454.03
2-1
2-M
2-E
2
2
2
4-23-87
4-23-87
4-23-87
1220
1235
1250
25
27
29
10.21
7.35
10.67
0.60
0.50
0.40
14.7
14.5
14.9
11.04
7.88
11.33
338
245
210
1.41
1.41
1.41
476.6
345.5
296.1
27.7
26.6
26.3
0.40
0.30
0.43
54.52
28.21
34.76
136.80
95.22
80.70
PASS 2
SUMMARY
-
-
-
-
-
14.7
10.14
793
1.41
1118.1
27.0
0.38
117.50
312.72
3-1
3-M
3-E
3
3
3
4-23-87
4-23-87
4-23-87
1320
1405
1425
31
33
35
7.52
9.48
12.58
1.00
0.50
0.90
15.0
14.9
14.9
8.43
10.16
13.98
325
245
223
1.46
1.46
1.46
474.5
357.7
325.6
27.7
26.6
26.3
0.30
0.38
0.53
41.45
37.66
47.17
136.20
98.60
88.73
PASS 3
SUMMARY
-
-
-
-
-
14.9
10.53
793
1.46
1157.8
27.0
0.39
126.28
323.54
4-1
4-M
4-E
4
4
4
4-23-87
4-23-87
4-23-87
1435
1415
1345
36
34
32
7.41
9.02
9.70
0.80
0.95
1.70
15.0
14.9
14.9
8.16
10.07
11.64
293
210
176
1.55
1.55
1.55
454.2
325.5
272.8
27.5
25.9
25.2
0.30
0.39
0.46
38.40
33.97
32.91
129.42
87.36
71.24
PASS 4
SUMMARY
-
-
-
-
-
14.9
9.65
679
1.55
1052.5
26.4
0.37
105.28
288.02
TANK 2
SUMMARY
14.8
10.54
3329
1.46
4871.2
27.3
0.39
532.04
1378.31
-------
OFF-GAS TEST RESULTS FOR JUNE 18, 1987
TEST
OCATION
PASS
NO.
DATE
TIME
RUN
NO.
MEAS.
OTE.X
DO,
MG/L
ML
TEMP,
DEG C
ALPHA X
SOTE, X
NO. OF
DOMES
AIRFLOW
SCFM
TOTAL
AIRFLOW,
SCFM
NEW
SOTE, X
APPARENT
ALPHA
ALPHA X
SOTR,
LBS. 02/HR
NEW SOTR,
LBS. 02/HR
1-1
1-M
1-E
1
1
1
6-18-87
6-18-87
6-18-87
1115
1050
1030
5
3
1
5.24
7.67
9.86
2.20
1.50
1.20
21.5
22.0
22.0
6.66
8.90
11.06
489
352
223
1.50
1.50
1.50
733.5
528.0
334.5
29.5
28.2
26.3
0.23
0.32
0.42
50.62
48.70
38.34
224.23
154.30
91.16
PASS 1
SUMMARY
-
-
-
-
-
21.8
8.32
1064
1.50
1596.0
28.4
0.29
137.66
469.69
2-1
2-H
2-E
2
2
2
6-18-87
6-18-87
6-18-87
1040
1100
1125
2
4
6
10.35
9.71
9.76
2.45
1.65
1.50
22.0
22.0
22.0
13.48
11.46
11.33
338
245
210
0.60
0.60
0.60
202.8
147.0
126.0
29.9
28.7
28.3
0.45
0.40
0.40
28.33
17.46
14.79
62.84
43.72
36.95
PASS 2
SUMMARY
-
-
-
-
-
22.0
12.29
793
0.60
475.8
29.1
0.42
60.58
143.51
3-1
3-M
3-E
3
3
3
6-18-87
6-18-87
6-18-87
1200
1240
1250
7
10
11
4.38
7.69
9.63
4.70
2.70
2.70
22.5
22.0
22.0
8.14
10.34
12.95
325
245
223
0.60
0.60
0.60
195.0
147.0
133.8
29.9
28.7
28.3
0.27
0.36
0.46
16.45
15.75
17.96
60.42
43.72
39.24
PASS 3
SUMMARY
-
-
-
-
-
22.2
10.17
793
0.60
475.8
29.1
0.35
50.16
143.38
4-1
4-M
4-E
4
4
4
6-18-87
6-18-87
6-18-87
1300
1230
1210
12
9
8
5.83
8.04
8.92
0.70
0.25
0.50
21.0
21.0
22.0
6.29
8.29
9.29
293
210
176
0.40
0.40
0.40
117.2
84.0
70.4
29.5
27.9
27.1
0.21
0.30
0.34
7.64
7.22
6.78
35.83
24.29
19.77
PASS 4
SUMMARY
-
-
-
-
-
21.3
7.69
679
0.40
271.6
28.4
0.27
21.63
79.88
TANK 2
SUMMARY
21.8
9.24
3329
0.85
2819.2
28.6
0.32
270.02
836.46
-------
OFF-GAS TEST RESULTS FOR JUNE 18, 1987
TEST
OCATION
PASS
NO.
DATE
TIME
RUN
NO.
MEAS.
OTE.X
DO,
MG/L
ML
TEMP,
DEG C
ALPHA X
SOTE, X
NO. OF
DOMES
AIRFLOW
SCFM
TOTAL
AIRFLOW,
SCFM
NEW
SOTE, X
APPARENT
ALPHA
ALPHA X
SOTR,
LBS. 02/HR
NEW SOTR,
LBS. 02/HR
1-1
1-M
1-E
1
1
1
6-18-87
6-18-87
6-18-87
1415
1445
1505
19
22
24
6.19
8.22
11.32
1.20
0.80
0.60
22.0
21.5
21.5
6.95
8.90
12.00
489
352
223
1.50
1.50
1.50
733.5
528.0
334.5
29.5
28.2
26.3
0.24
0.32
0.46
52.83
48.70
41.60
224.23
154.30
91.16
PASS 1
SUMMARY
-
-
-
-
-
21.7
8.65
1064
1.50
1596.0
28.4
0.30
143.12
469.69
2-1
2-M
2-E
2
2
2
6-18-87
6-18-87
6-18-87
1455
1435
1425
23
21
20
10.46
8.36
9.24
1.40
1.60
1.20
21.5
21.5
21.5
12.09
9.88
10.44
338
245
210
0.60
0.60
0.60
202.8
147.0
126.0
29.9
28.7
28.3
0.40
0.34
0.37
25.41
15.05
13.63
62.84
43.72
36.95
PASS 2
SUMMARY
-
-
-
-
-
21.5
10.97
793
0.60
475.8
29.1
0.38
54.09
143.51
3-1
3-M
3-E
3
3
3
6-18-87
6-18-87
6-18-87
1350
1330
1310
17
15
13
5.88
7.71
9.41
4.20
3.00
2.70
22.0
22.0
22.0
9.87
10.80
12.66
325
245
223
0.60
0.60
0.60
195.0
147.0
133.8
29.9
28.7
28.3
0.33
0.38
0.45
19.94
16.45
17.55
60.42
43.72
39.24
PASS 3
SUMMARY
-
-
-
-
-
22.0
10.94
793
0.60
475.8
29.1
0.38
53.95
143.38
4-1
4-M
4-E
4
4
4
6-18-87
6-18-87
6-18-87
1320
1340
1400
14
16
18
6.03
7.3
8.27
0.70
0.40
0.50
21.0
21.0
21.0
6.51
7.64
8.75
293
210
176
0.40
0.40
0.40
117.2
84.0
70.4
29.5
27.9
27.1
0.22
0.27
0.32
7.91
6.65
6.38
35.83
24.29
19.77
PASS 4
SUMMARY
-
-
-
-
-
21.0
7.44
679
0.40
271.6
28.4
0.26
20.94
79.88
TANK 2
SUMMARY
21.5
9.31
3329
0.85
2819.2
28.6
0.33
272.10
836.46
-------
OFF-GAS TEST RESULTS FOR JUNE 18, 1987
ML
TOTAL
ALPHA X
TEST
PASS
RUN
MEAS.
DO,
TEMP,
ALPHA X
NO. OF
AIRFLOW
AIRFLOW,
NEW
APPARENT
SOTR,
NEW SOTR,
DCATION
NO.
DATE
TIME
NO.
OTE,X
MG/L
DEG C
SOTE, X
DOMES
SCFM
SCFM
SOTE, X
ALPHA
LBS. 02/HR
LBS. 02/HR
1-1
1
6-18-87
1605
30
6.93
1.15
21.5
7.79
489
1.50
733.5
29.5
0.26
59.21
224.23
1-M
1
6-18-87
1545
28
8.13
1.20
21.5
9.19
352
1.50
528.0
28.2
0.33
50.28
154.30
1-E
1
6-18-87
1525
26
10.76
0.60
21.5
11.41
223
1.50
334.5
26.3
0.43
39.55
91.16
PASS 1
SUMMARY
-
-
-
-
-
21.5
9.01
1064
1.50
1596.0
28.4
0.32
149.05
469.69
2-1
2-M
2-E
2
2
2
6-18-87
6-18-87
6-18-87
1515
1535
1555
25
27
29
10.27
10.12
10.10
1.30
1.50
1.20
21.5
21.5
21.5
11.74
11.83
11.42
338
245
210
0.60
0.60
0.60
202.8
147.0
126.0
29.9
28.7
28.3
0.39
0.41
0.40
24.67
18.02
14.91
62.84
43.72
36.95
PASS 2
SUMMARY
-
-
-
-
-
21.5
11.68
793
0.60
475.8
29.1
0.40
57.60
143.51
3-1
3-M
3-E
3
3
3
6-18-87
6-18-87
6-18-87
1620
1650
1710
31
34
36
5.57
7.21
9.95
4.00
2.40
2.10
22.0
22.0
22.0
9.05
9.33
12.40
325
245
223
0.60
0.60
0.60
195.0
147.0
133.8
29.9
28.7
28.3
0.30
0.32
0.44
18.29
14.21
17.19
60.42
43.72
39.24
PASS 3
SUMMARY
-
-
-
-
-
22.0
10.08
793
0.60
475.8
29.1
0.35
49.69
143.38
4-1
4-M
4-E
4
4
4
6-18-87
6-18-87
6-18-87
1700
1640
1630
35
33
32
5.76
8.22
9.20
0.20
0.15
0.20
21.5
21.5
21.5
5.86
8.33
9.37
293
210
176
0.40
0.40
0.40
117.2
84.0
70.4
29.5
27.9
27.1
0.20
0.30
0.35
7.12
7.25
6.84
35.83
24.29
19.77
PASS 4
SUMMARY
-
-
-
-
-
21.5
7.53
679
0.40
271.6
28.4
0.27
21.20
79.88
TANK 2
SUMMARY
21.6
9.50
3329
0.85
2819.2
28.6
0.33
277.55
836.46
-------
OFF-
•GAS TEST
RESULTS FOR
AUGUST '
13, 1987
ML
TOTAL
ALPHA X
TEST
PASS
RUN
ME AS.
DO,
TEMP,
ALPHA X
NO. OF
AIRFLOW
AIRFLOW,
NEW
APPARENT
SOTR,
NEW SOTR,
SCAT ION
NO.
DATE
TIME
NO.
OTE,X
MG/L
DEG C
SOTE, X
DOMES
SCFM
SCFM
SOTE, X
ALPHA
LBS. 02/HR
IBS. 02/HR
1-1
1
8-13-87
1220
6
8.87
0.21
24.8
8.96
489
2.10
1026.9
27.8
0.32
95.35
295.83
1-M
1
8-13-87
1200
4
9.51
0.30
24.8
9.70
352
2.10
739.2
26.7
0.36
74.30
204.52
1-E
1
8-13-87
1140
2
8.15
0.31
24.9
8.32
223
2.10
468.3
25.3
0.33
40.38
122.78
PASS 1
SUMMARY
-
-
-
-
-
24.8
9.07
1064
2.10
2234.4
26.9
0.34
210.03
623.13
2-1
2
8-13-87
1130
1
11.62
0.38
24.7
11.67
338
2.20
743.6
26.0
0.45
89.93
200.35
2-M
2
8-13-87
1150
3
10.40
0.50
24.7
10.84
245
2.20
539.0
25.2
0.43
60.55
140.75
2-E
2
8-13-87
1210
5
11.92
0.38
24.8
12.26
210
2.20
462.0
25.0
0.49
58.70
119.69
PASS 2
SUMMARY
-
-
-
-
-
24.7
11.57
793
2.20
1744.6
25.5
0.45
209.17
460.79
3-1
3
8-13-87
1235
7
9.17
0.12
24.6
9.18
325
2.20
715.0
26.0
0.35
68.02
192.64
3-M
3
8-13-87
1255
9
11.52
0.61
24.6
12.16
245
2.20
539.0
25.2
0.48
67.92
140.75
3-E
3
8-13-87
1325
12
12.52
0.81
24.7
13.51
223
2.20
490.6
25.0
0.54
68.68
127.10
PASS 3
SUMMARY
-
-
-
-
-
24.6
11.32
793
2.20
1744.6
25.5
0.44
204.62
460.50
4-!
4
8-13-87
1315
11
6.21
0.35
24.6
6.37
293
2.60
761.8
25.0
0.25
50.29
197.36
4-M
4
8-13-87
1305
10
7.69
0.73
24.6
8.23
210
2.60
546.0
24.0
0.34
46.57
135.79
4-E
4
8-13-87
1245
8
10.36
0.86
24.5
11.25
176
2.60
457.6
23.5
0.48
53.35
111.44
PASS 4
SUMMARY
-
-
-
-
-
24.6
8.21
679
2.60
1765.4
24.3
0.34
150.20
444.59
TANK 2
SUMMARY
24.7
9.97
3329
2.25
7489.0
25.6
0.39
774.01
1989.01
-------
OFF-
GAS TEST
RESULTS FOR
AUGUST 13
i, 1987
ML
TOTAL
ALPHA X
TEST
PASS
RUN
MEAS.
DO,
TEMP,
ALPHA X
NO. OF
AIRFLOW
AIRFLOW,
NEW
APPARENT
SOTR,
NEW SOTR,
3CATI0N
NO.
DATE
TIME
NO.
OTE,X
MG/L
DEG C
SOTE, X
DOMES
SCFM
SCFM
SOTE, X
ALPHA
LBS. 02/HR
LBS. 02/HR
1-1
1
8-13-87
1450
20
9.41
0.36
24.7
9.66
489
2.10
1026.9
27.8
0.35
102.80
295.83
1-M
1
8-13-87
1510
22
9.56
0.21
24.8
9.66
352
2.10
739.2
26.7
0.36
74.00
204.52
1-E
1
8-13-87
1520
23
9.69
0.12
24.9
9.69
223
2.10
468.3
25.3
0.38
47.02
122.78
PASS 1
SUMMARY
-
-
-
-
-
24.8
9.67
1064
2.10
2234.4
26.9
0.36
223.82
623.13
2-1
2
8-13-87
1540
24
9.76
0.14
24.8
9.79
338
2.20
743.6
26.0
0.38
75.44
200.35
2-M
2
8-13-87
1500
21
10.73
0.46
24.8
11.14
245
2.20
539.0
25.2
0.44
62.22
140.75
2-E
2
8-13-87
1440
19
9.77
0.36
24.6
10.04
210
2.20
462.0
25.0
0.40
48.07
119.69
PASS 2
SUMMARY
-
-
-
-
-
24.7
10.27
793
2.20
1744.6
25.5
0.40
185.73
460.79
3-1
3
8-13-87
1425
18
7.85
0.14
24.7
7.88
325
2.20
715.0
26.0
0.30
58.39
192.64
3-M
3
8-13-87
16 not
performed
-
-
245
-
-
-
-
-
-
3-E
3
8-13-87
1345
14
12.29
0.72
24.7
13.13
223
2.20
490.6
25.0
0.53
66.75
127.10
PASS 3
SUMMARY
-
-
-
-
-
24.7
10.02
793
2.20
1205.6
25.6
0.39
125.14
319.74
4-1
4
8-13-87
1335
13
5.94
0.41
24.6
6.14
293
2.60
761.8
25.0
0.25
48.47
197.36
4-M
4
8-13-87
1355
15
7.54
0.57
24.6
7.93
210
2.60
546.0
24.0
0.33
44.87
135.79
4-E
4
8-13-87
1415
17
10.76
0.79
24.6
11.59
176
2.60
457.6
23.5
0.49
54.96
111.44
PASS 4
SUMMARY
-
-
-
-
-
24.6
8.11
679
2.60
1765.4
24.3
0.33
148.30
444.59
TANK 2
SUMMARY
24.7
9.48
3329
2.09
6950.0
25.7
0.37
682.98
1848.25
-------
OFF-
GAS TEST
RESULTS FOR
AUGUST '
13, 1987
ML
TOTAL
ALPHA X
TEST
PASS
RUN
ME AS.
DO,
TEMP,
ALPHA X
NO. OF
AIRFLOW
AIRFLOW,
NEW
APPARENT
SOTR,
NEW SOTR,
3CATI0N
NO.
DATE
TIME
NO.
OTE,X
MG/L
DEG C
SOTE, X
DOMES
SCFM
SCFM
SOTE, X
ALPHA
LBS. 02/HR
LBS. 02/HR
1-1
1
8-13-87
1630
29
8.83
0.25
24.9
8.96
489
2.10
1026.9
27.8
0.32
95.35
295.83
1-M
1
8-13-87
1610
27
8.56
0.35
24.9
8.78
352
2.10
739.2
26.7
0.33
67.26
204.52
1-E
1
8-13-87
1550
25
9.88
0.21
24.9
9.98
223
2.10
468.3
25.3
0.39
48.43
122.78
PASS 1
SUMMARY
-
-
-
-
-
24.9
9.11
1064
2.10
2234.4
26.9
0.34
211.03
623.13
2-1
2
8-13-87
1600
26
9.28
0.26
24.8
9.43
338
2.20
743.6
26.0
0.36
72.66
200.35
2-M
2
8-13-87
1620
28
11.38
0.17
24.8
11.45
245
2.20
539.0
25.2
0.45
63.95
140.75
2-E
2
8-13-87
1640
30
9.14
0.34
24.9
9.36
210
2.20
462.0
25.0
0.37
44.81
119.69
PASS 2
SUMMARY
-
-
-
-
-
24.8
10.04
793
2.20
1744.6
25.5
0.39
181.43
460.79
3-1
3
8-13-87
1710
32
9.16
0.22
24.8
9.26
325
2.20
715.0
26.0
0.36
68.61
192.64
3-M
3
8-13-87
1730
34
12.73
0.54
24.8
13.33
245
2.20
539.0
25.2
0.53
74.45
140.75
3-E
3
8-13-87
1750
36
13.49
0.61
24.8
14.23
223
2.20
490.6
25.0
0.57
72.34
127.10
PASS 3
SUMMARY
-
-
-
-
-
24.8
11.92
793
2.20
1744.6
25.5
0.47
215.41
460.50
4-1
4
8-13-87
1740
35
4.72
0.19
24.8
4.76
293
2.60
761.8
25.0
0.19
37.58
197.36
4-M
4
8-13-87
1720
33
8.15
0.25
24.8
8.27
210
2.60
546.0
24.0
0.34
46.79
135.79
4-E
4
8-13-87
1700
31
10.63
0.60
24.7
11.22
176
2.60
457.6
23.5
0.48
53.20
111.44
PASS 4
SUMMARY
-
-
-
-
-
24.8
7.52
679
2.60
1765.4
24.3
0.31
137.57
444.59
TANK 2
SUMMARY
24.8
9.61
3329
2.25
7489.0
25.6
0.37
745.45
1989.01
-------
APPENDIX I-B
PHOTO PLATES OF AERATION DIFFUSERS,
CLEANING, AND OFF-GAS EQUIPMENT
133
-------
PHOTO PLATE P-l OFF-GAS EQUIPMENT
P-X.l
OFF-GAS ANALYZER APPARATUS
&&&&&&£&£:""
V V. * '* ' W'»»' «
P-l. 2
FLEXIBLE MEMBRANE OFF-GAS COLLECTION HOOD
134
-------
PHOTO PLATE P-2 AERATION SYSTEM
P-2.1 NOCARDIA FOAM PROBLEM AT DISSOLVED OXYGEN
CONCENTRATION GREATER THAN 1.0 MG/L
P-2.2 COARSE BUBBLES AT SURFACE (COARSING CONDITION) MOST
PREVALENT AT AERATION TANK INFLUENT POINTS
-------
PHOTO PLATE P—3 DIRTY DOMES
P-3.1 BEFORE CLEANING ON OCTOBER 21, 1985 (AFTER 3 YEARS
OF CONTINUOUS OPERATION)
P-3.2 AFTER HIGH PRESSURE HOSING ON OCTOBER 21, 1985
(CERAMIC DOME DID NOT CLEAN OFF)
-------
PHOTO PLATE P-4 DIRTY DOMES
P-4.1 AFTER DEWATERING AERATION TANK AND BEFORE CLEANING
(OCTOBER 21, 1985)
J 1 »* «'i**
P-4.2 AFTER DEWATERING AERATION TANK AND BEFORE CLEANING
(AIR WAS NOT SHUT OFF AFTER DEWATERING—SLUDGE HAS
DRIED ON)
i
-------
PHOTO PLATE P-S INITIAL CLERKING
P-5.1 AFTER HIGH PRESSURE HOSING AND ACID CLEANING
(OCTOBER 21, 1985)
P-5.2 COMPLETELY CLEANED AERATION TANK PASS
(OCTOBER 21, 1985)
13£
-------
PHOTO PLATE P-6 DIRTY DOMES
P-6. 2 CLOSEUP OF INLET END OF AERATION PASS ON MAY 1, 1987
139
-------
PHOTO PLATS P-7 HIGH PRESSURE HOSING
P-7.1
HIGH PRESSURE HOSING OF GRID SYSTEM IMMEDIATELY
AFTER DEWATERING (MAY 1, 1987}
P-7.2
, I { ' ¦» i f ,
ffi
; TiJf ¦*;* :* * *
I f ? f ? f »
.• |V,i 1 t *
HIGH PRESSURE HOSING OF GRID SYSTEM IMMEDIATELY
AFTER DEWATERING (MAY 1, 1987)
P"'«Hlu V
ii:
140
-------
PHOTO PLATE P—8 ACID CLEANING
P-8.1 APPLYING ACID TO DOMES (MAY 1, 1987}
P-8.2 APPLYING ACID TO DOMES (MAY 1, 1987)
141
-------
ASCE/EPA OXYGEN TRANSFER STUDY
HARTFORD, CT MDC FACILITY
AERATION TANK NO. 2
PHOTO PLATE P-9 ACID CLEANING
P-9.1 LOW AIRFLOW GASSING TO CHECK FOR LEAKS (MAY 1, 1987)
NOTE SURFACE RIPPLES AT LEAK POINTS
P-9.2 "AIRING" DOMES AFTER ACID APPLICATION (HAY 1, 1987)
142
-------
ASCE/EPA OXYGEN TRANSFER STUDY
HARTFORD/ CT MDC FACILITY
AERATION TANK NO. 2
PHOTO PLATE P-10 LEAK REPAIR
P-10.1 LEAK DETECTION AND REPAIR (NOTE RAISED AIR LATERAL
IN FRONT OF WORKER (PIPE SUPPORT STRAP BROKEN)
P-10.2 CHECKING FOR LEAKS AT DOME SEAT GASKETS AND AT
DOME BOLT LOCATIONS (MAY 1, 1987)
143
-------
ASCE/EPA OXYGEN TRANSFER STUDY
HARTFORD, CT MDC FACILITY
AERATION TANK NO. 2
PHOTO PLATE P-ll WORN OUT GASKETS
P-ll.l DISCARDED DOME SEAT GASKETS - AGE ABOUT 5.5 YRS.
(MAY 1, 1987)
P-ll.2 BROKEN DOME SEAT GASKET. NO PLASTICITY OR
ELASTICITY LEFT; MANY CRACKS IN GASKET
144
-------
APPENDIX I-C
overall plant data sheet
BASED ON
PREVIOUS YEAR OF RECORD
AND
SUPPLEMENTAL INFORMATION
145
-------
EXHIBIT A.l: OVERALL PLAFI DATA 8HEET
BASED OK PREVIOUS YEAR OF RECORD
Plant Name: HARTFORD WATER POLLUTION CONTROL PLANT
Location: HARTFORD, CT
Flow Through Secondary Treatment:
Average: 47.6 MGD
Maximum: 58.1 MGD
1. WASTEWATER CHARACTERISTICS - BASED ON MONTHLY AVERAGES
Temperature, Deg. C:
Average: 19
Minimum: 14
Maximum: 23
Raw Influent,
mg/1
Sec.
Eff. ,
ma/1
Parameter
Ava. Min.
Max.
Avq.
Min.
Max
bod5(1)
133 77
172
11
6
16
COD
* *
*
*
*
*
TSS
152 115
216
18
8
33
TDS
* *
*
*
*
*
TKN
* *
*
*
*
*
Total P
* *
*
*
*
*
pH (units)
7.2 7.1
7.3
7.2
7.1
7.3
Alk
* *
*
*
*
*
Hardness
* *
*
*
*
*
Nitrate - N
* h
*
*
*
*
* not available and/or not determined
(1) see monthly average data at end of this Appendix.
146
-------
2. PROCESS FLOW DIAGRAM INCLUDING TANK SIZES AND RETURN
FLOWS FROM SLUDGE PROCESSING
Process Flow Diagram:
Primary Sed. Area:
See Figure No. 1 of report.
Each tank, east side 4 § 5,040 sq. ft.
Each tank, west side 8 § 6,750 sq. ft.
Final Clar. Area:
Each of 6 § 12,237 sq. ft.
Aeration Tank Vol.:
Each tank of 4 0 232,000 cu. ft.
Aeration Tank Water Depth:
Nominal: 15.5 ft.
3. MAJOR INDUSTRIAL WASTES
~ no major industrial streams
~ 7 to 10 percent of flow is industrial and commercial
4. RETURN FLOWS FROM SLUDGE PROCESSING - AVERAGES
Source
Flow. MGD BOD.mcf/1 TSS,mq/l TKN.mq/1 pH
Dewatering
Filtrate 0.478
D.A.F.
Thickener 1.58 -
Overflow 3.46
1,750
500
6.2
7.0
* not available and/or not determined
147
-------
5. PRIMARY EFFLUENT CHARACTERISTICS
Average Including Return Flows
Flow: 47.6 MGD
BOD: 95 mg/1
TSS: 98 mg/1
TKN: *
TDS: *
Oil and Grease: *
* not available and/or not determined
6. PROCESS PARAMETERS - BASED OK AVERAGE CONDITIONS
+/- percent variability
Parameter max. no. to min. no.
Primary Overflow Rate, East 794 East +/- 10.0
gpd/sf West 593 West +/- 10.0
Aeration Detention Time,
V/Q 4.5 +47, -24
MLSS Cone., mg/1 3,342<1> +67, -36
Ratio, MLVSS/MLSS 0.759 +/- 5.0
Solids Wasting Rate,
lbs., MLSS/day 44,590 +/- 34
Sludge Volume Index 166 +98, -48
Recycle Ratio, R/Q 40 +20, -33
Sludge Age, Days(2) 6.5c3) -
F/M Ratio, per day(2)
(based on MLVSS) 0.26
(1> see monthly average data at end of this Appendix.
(Z) estimated clarifier holdup included in solids
inventory.
MCRT (see equation in Report Table No. 6
for calculation method).
148
-------
7. AIR DIFFUSION SYSTEM
Tank Designation: Aeration Tank No. 2
Diffusers, Type and Number: Norton
Ceramic 7-in. diameter Dome Diffusers (See
Figure Nos. 2,3,4,5 & 6 of Report).
For number and distribution see Figure No. 7 of
Report.
Recommended Air Rates for this Diffuser, SCFM:
Grids with > 133 domes
min. 0.5 SCFM max. 2.5 SCFM
Grids with < 133 domes
min. 0.5 SCFM max. 2.5 SCFM
plus min. mixing airflow of 0.12 SCFM
per sq. ft. of tank floor area.
Typical Wet Resistance for this Diffuser over the Rec.
Air Rate Range:
at Min. Rate at Max. Rate
Orifice Resistance, in. H20 0.5* 13.5*
Clean Diffusers, in. H20 5.0* 20.5*
Dirty Diffuser, in. HzO ** **
Year Installed: Fall 1982
Submergence, ft.: 14.5
Water Dept, ft.: 15.5
Cleaning Practice and History: Acid cleaned by the
"Modified Milwaukee Method" in October 1985 and May
1987.
Sketch of Diffuser Arrangement in Tank:
See Figure Nos. 4,5,6 and 7 of Report
* See Report Figure No. 12
** See Appendix I-D, Dome Diffuser Characterization Tests
149
-------
8. BLOWERS AND AIR SUPPLY PIPING
Blower
No. Type. Brand, Model Yr. HP
2
3
RPM
SCFM
Op. Tim.
Hr/Year
Multistage Centrifugal
Brown-Boveri 1972 3000 3583 60,000 2920(est.)
VI1 22VdVl
Total Installed Blower HP: 9,000
Total Installed Blower SCFM: 180,000
Description of Air Filtration System:
Disposable, fiberglass "Biocell" filters installed
ahead of oil bath coarse filters.
Supplemental Information on Blower Drives:
Drive
No.
Drive
Type
HP at
Design Design
Brand
Squirrel
Cage Brown
Induction Boveri
Model
MQGyn
222KO
Yr.
1972
RPM
3583
RPM
3000
2
3
Typical Blowers Used at Average Operating Conditions:
Blower Numbers: 1
Total Horsepower: 3,000
Measured Pressure at Blower Discharge, psi: 7.2 +/-
Measured Dynamic Wet Pressure at Diffuser, psi: NA
Nominal Airflow per Diffuser, SCFM: 1.0 to 2.0
Typical Blowers Used at Maximum Operating Conditions:
Blower Numbers: 1
Total Horsepower: 3,000
Measured Pressure at Blower Discharge, psi: 7.5 +/-
Nominal Airflow per Diffuser, SCFM: 3.0
150
-------
Blower Turndown Capability:
Excluding Channel Airflow
with Channel Airflow
9,000 SCFM
19,000 SCFM
Strategy Used to Manage Blowers:
Manual control, maintaining a positive DO in the
fourth pass for at least 12 hours per day. Adjust-
ments in airflow made by guide vane control.
Airflow and KW monthly average data is contained at
the end of this Appendix.
Arrangement of Blowers and Transmission Piping:
Air piping is under the floor slab in blower build-
ing, and the main air piping runs in a utility tun-
nel between the aeration tanks.
Data Base for Aeration Tank Dissolved Oxygen:
Frequency of Measurement: All passes of two tanks
twice daily. The fourth pass of some tanks - con-
tinuous chart recorders in use.
Number of Locations: 8
Length of Record: 2+ years
Typical Aeration Tank DO Values:
Quarter Average Minimum
9. RESULTS OF PREVIOUS OXYGEN TRANSFER TESTS AT THIS PLANT:
- none conducted -
L. A. County work by Yunt and dome diffuser develop-
ment testing conducted by AERTEC used for estab-
lishment of SOTE values.
1st
2nd
3rd
4 th
0.8
0.7
1.1
1.6
0
0
0
0
(no maximum values available)
m* ADDITIONAL COMMENTS
- See attached supplemental information -
151
-------
Total Air Flow
BOD
MLSS
Month
(lOOOxCFM)
Power (KW)
(lOOOxlb/day)
(mg/1)
A '83
24.8
23.0
2197
S
29.0
27.5
1825
0
21.0
766
24.9
2314
N
23.3
819
38.6
4589
D
19.0
709
20.9
4521
CO
21.8
784
31.9
4566
F
19.7
726
28.3
4614
M
16.7
649
33.8
4232
A
16.6
657
31.8
3377
H
21.3
800
34.3
3746
J
19.3
751
24.6
2939
J
21.1
794
37.6
3831
A
22.3
841
35.3
3172
S
28.5
998
58.8
3950
0
29.1
1024
56.3
3763
N
28.5
1042
43.0
3450
D
27.1
1013
43.4
3665
J '85
27.3
1013
50.2
5575
F
26.4
987
45.9
4215
M
32.1
1043
41.5
4152
A
33.8
1052
39.6
4137
M
29.9
977
34.0
3259
J
35.6
1100
36.6
5033
J
31.9
1001
32.8
3480
A
23.8
831
34.5
2606
152
-------
60
I
3
X
o
55 -
SO -
45 -
40 -
35
30
25
20
t—r-
A S O
D J
"T"
F
T~
M
~i—r
J J
-j—i—r-
A S 0
1~
D
T"
r
1 1 T~
M A M
i—r
J J
MONTH
MONTH
153
-------
MONTH
MONTH
154
-------
TIME OF DAY
-------
APPENDIX Z-D
DOME DIFFDSER CHARACTERIZATION TESTS
BEFORE AND AFTER CLEANING
(APRIL AND MAY 1987)
156
-------
UNIVERSITY OF WISCONSIN-MADISON
DEPARTMENT OF CIVIL AND
ENVIRONMENTAL ENGINEERING
July 8, 1987
Engineering Building
1415 Johnson Drive
Madison. Wisconsin 53706
Telephone: 608/262-
Gary Gilbert
Aeration Technologies Inc.
P.O. Box 488
N. Andover, MA 01845
Dear Gary:
Enclosed are the test results that we performed on the Norton dome diffusers
at Hartford, Connecticut, before and after cleaning.
1 think the data pretty much speaks for itself. The "dirty" diffusers were
very fouled producing high BRV values (range - 19 to 75 in. wg). You may note
that at several points on the diffuser, it was totally clogged (BRV value in
the raw tables of 7.5 in. Hg means no flow - in excess of 200 in. wg).
Distribution of foulant was uneven, thereby resulting in most of the flow (a)
through the lightly fouled portions of the stone,-(b) through the gasket, and
(c) around the bolt hole. This is clearly demonstrated by the high flux rates
at the "inner" and "outer" circle. DWP values were low because much of the
air leaked around the gaskets! Net result of this would be coarse bubbles,
low SOTE.
Cleaning greatly improved uniformity of fouled areas, and flux was therefore
more uniform as well. Bubble patterns were not bad. BRV values in two cases
were above 14 in. wg, which is a little high for cleaned diffusers (clean
stones are about 6-7 in. wg).
Foulant on the stones was high (-30 mg/cm^) but not unusual for long periods
between cleaning. The percent volatiles were typical of so many of the plants
we have studied (usually under 10%).
I would expect that cleaning should improve SOTE at Hartford if gaskets are
good and diffusers are properly tightened down and level. Please let me know
if there is further information you need.
Sincerely,
William C. Boyle
Professor
WCB/jle
157
-------
SUMMARY DF DIFFUSER CHARACTERIZATION DATA
Dif fusers Received From: Hart-ford, CT
Date Received: 5/09/B7 Tank 2, Pass 2, In-f.
Date Dif-fuser Dif-fuser
Tested Type Condition and Identification Avg. BRV S / x
5/09/87
Norton
#9,11
75.313
0.743
5/09/87
Norton
# 6,?
19.048
0. 527
5/09/87
Norton
# 3,3
57.799
0.902
. 5
c-fm
DUIF' (i n wg. >
.75 1.0
c-fm c-fm
2. 0
c-fm
Rati o
DWF'il.75
BRV
5/09/87
#9,11
10.0
11.6 12.3
24. 2
0. 154
5/09/87
# 6,?
7.8
8.7 9.3
13.5
0. 457
5/09/87
# 3,3
7.2
7.6 8.2
11.2
0. 131
Flux Rate
Inner
(cf m/sqft)
Air Flow Pro-file
Flux Rate
Mi ddle
(c-f m/sq-f t >
Flux Rate
Outer
(c-f m/sq-f t
# 9, 1 1
1.94
0. 26
6. 10
# 6,?
1.95
0.81
5. 61
# 3,3
0.28
0.02
6.97
158
-------
FOULANT SUMMARY SHEET
FOR
FINE BUBBLE DIFFUSERS
Diffusers Recieved From:
Date Received: 5/09/87
Hartford, CT
Tank 2, Pass
2, Inf.
Date
Tested
Di ffuser
Type
Total
Soli ds
-------
Diffuser ID: Hartford, CT
# 9, 11
Descr i pt i on:
FOULANT:
There is a blackish material present underneath
a dark brown material across the stone. The
black foulant is hard, dry, and crusty. The
brown is slimy and wet. The black is present
mainly around the edges. The brown is spread
•fairly evenly across the stone.
FLOW: The flow is EXTREMELY uneven and mainly comes
from the edges in large bubbles. There are
some leaks present at the points of contact.
MISC.: The DWP varied during testing and would mot
stabilize.
A BRV value of 7.50 indicates that the point
is completely clogged. The paints vary a lot,
but are a good representation of the stones
characteristics.
*inches Hg
160
-------
Dif-fuser ID: Hartford, CT
# 6,7
Description:
FOULANT: There is a blackish material present underneath
a dark brown material across the stone. The
black -foul ant is hard, dry, and crusty. The
brown is slimy and wet. The black is present
mainly around the edges. The brown is spread
-fairly evenly across the stone.
FLOW: The -flow is EXTREMELY uneven and mainly comes
•from the edges in large bubbles. There are
some leaks present at the points o-f contact.
MISC.: The DWP varied during testing, but did finally
stabi1i ze.
Many points were taken during BRV testing to
come up with the averages shown.
161
-------
Diffuser ID: Hartford, CT
# 3,3
Descr i pt i on:
FOULANT: There is a blackish material present underneath
a dark brown material across the stone. The
black foulant is hard, dry, and crusty. The
brown is slimy and wet. The black is present
mainly around the edges. The brown is spread
unevenly across the stone.
FLOW: The -Flow is EXTREMELY uneven and mainly comes
•from the edges in large bubbles. There are
some leaks present at the points o-f contact.
MISC.! The DWP varied during testing, but did -finally
st. ab i 1 i z e.
A BRV value of 7.50 indicates that the point is
completely clogged. The values vary a lot. but
are a good representation of the stones
characteristics. Alternate paints were tested
on all stones, the best values were recorded.
~inches Hg
162
-------
NORTON/GRAY DOME DIFFUSER CHARACTERIZATION SHEET
DIFFUSER I DENTIFICATION-
Hart-ford. CT / Tank #2 Pass #2, Inf,
#9,11 / Removed 5/05/B7
DATE —
5/09/87
LOCATION
BRV
(i n HG)
H20 Height
(in H20)
BRV TOTAL
(in H20)
1
6
7
8
IS
4S
5S
8S
0. 50
1. 50
3.80
O. 90
2.00
4. 95
3. 60
2. 40
4. 10
2. 20
7. 50
O > 55
1. 50
1. 50
1. 60
1. 50
1. 70
1. 60
1. 50
1. 50
1. 75
1.55
1.60
1.70
12.
39.
101 .
07
21
53
22.93
52.58
132.74
96. 20
63.64
109.52
58. 16
201.95
13.23
65.113
0. 644
TOP
x
s/>
75.313 OVERALL
0. 743
S / =
95.715
0.846
SIDES
DWP vs FLOW
ROTO
RDG
FLOW
(cfra)
DWP
(i n wg)
DWP(actual)
(in wg)
91 2.08 30.3 25.
21 0.50 29.2 24.
33 0.75 17.3 12.
43 1.00 16.6 11.
87 2.00 15.0 10.
water above di-f-fuser =
Height o-f
FLOW PROFILE (3 bucket catch)
VOLUME
(cc >
TIME
(sec)
TOTAL FLOW
(cc/sec)
i. 0 in.
ANNULAR FLOW
per sq -ft
(cfm/sq -ft)
TOTAL ANN
FLOW
-------
NORTON/GRAY DOME DIFFUSER CHARACTERIZATION SHEET
DIFFUSER IDENTIFICATION—
Hartford., CT / Tank #2 Pass #2. Inf
#6,? / Removed 5/05/B7
DATE—
5/09/87
LOCATION
#
BRV
(in HG)
H20 Height
< i n H20>
BRV TOTAL
(in H20)
1
4
5
6
7
e
is
4S
5S
8S
0. 50
0.50
0.60
O. 90
0.60
0. 60
0.50
1. BO
0.50
0. BO
0.80
1.00
1.50
1.55
1.50
1.55
1 . 50
1. 50
1. 55
1.55
1.55
1,55
1.50
1.60
12.07
12.02
14.78
22.88
14.78
14.78
12.02
47. 30
12.02
20. 16
20.21
y, =
;/>: =
18.830
0. 639
TOP
i/y, =
19.048
0.527
OVERALL
>! =
S/X =
19.484
0. 286
SIDES
DWP vs FLOW
ROTO FLOW
RDG (c-fm)
DWP
( i n wg)
DWP(actual )
(in wg)
91
21
43
87
2.08
O. 50
0. 75
1. 00
2.00
18.8
18. 5
14.3
13.7
12.8
13.8
13.5
9.3
B. 7
7.8
Height of water above diffuser
FLOW PROFILE (3 bucket catch)
VOLUME
(cc)
TIME
(sec)
TOTAL FLOW
(cc/sec)
5.0 in.
ANNULAR FLOW
per sq ft
(cfm/sq ft)
TOTAL ANN
FLOW
(cfm)
OUTER
MIDDLE
INNER
NOTES-
10320
600
400
28.50
7.20
9.55
362. 1
83.3
41.9
5.61
0.81
1.95
Total Flow (cfm)
0.591
0.0B8
0.089
0.767
164
-------
NORTON/BRAY DOME DIFFUSER CHARACTERIZATION SHEET
DIFFUSER IDENTIFICATION— Hartford, CT / TanJ: #2 Pass #2, Inf
#3,3 / Removed 5/05/87
DATE-
5/09/87
LOCATION
#
BRV
(in HG)
H20 Height
(in H20)
BRV TOTAL
(in H20)
1
4
5
6
7
B
IS
4S
5S
BS
2. 10
1. 90
i . 80
1. 10
3.30
7.50
3.10
2. 40
0.45
0. 58
0.55
1. 50
1.50
1.50
1.60
1. 60
1.55
1.50
1 . 70
1 .75
1.80
1. 75
1. 70
1.70
55.49
50. 07
47. 25
00 '-ver
-£.0 •
88.01
202.05
82.43
63.39
10.41
13.99
13.23
39.01
s/x =
77.119
0. 700
TOP
x =
s/x =
57.799
0.902
OVERALL
s/>: =
19.160
0.695
SIDES
DWP vs FLOW
ROTO
RDG
FLOW
(cf m)
DWP
( i n wg)
91
21
33
43
87
2.08
0. 50
0. 75
1. 00
2. 00
16.3
16. 2
13.2
12.6
12.2
DWP(actual)
(i n wg)
11.3
11.2
8.2
7.6
7.2
Height o-f water above diffuser =
FLOW PROFILE (3 bucket catch)
VOLUME
(cc >
TIME
< sec)
TOTAL FLOW
(cc/sec >
5.0 in,
ANNULAR FLOW
per sq -ft
(c-fm/sq -ft)
TOTAL ANN
FLOW
(cf m)
OUTER
MIDDLE
INNER
NOTES—
10320
100
100
29.20
14.50
16.54
353. 4
6.9
6. 0
6.97 0.734
0.02 0.002
0.28 0.013
Total Flow (c-fm) = 0.749
165
-------
FOUL.ANT ANALYSIS FOR FINE BUBBLE DIFFUSERS
DIFFUSER TYPE: Norton
DIFFUSER IDENTIFICATION:
Hart-ford, CT
Diffuser Tank 2 Pass
Removed 5/05/87
Date Tested: 5/09/87
Area Scraped: 38.5 sq in
Note -All weights are in grams
Dry weight o-f dish = 44.B957
Dish + Foul ant = 57.3425
Wet Foul ant Weight = 12.446B
Dry Weight(Dish + Foulant) — 52.4544
Dry Foulant Weight = 7.55B7
Weight A-fter 550 degC = 51.9665
Non-Volatile Foulant Weight = 7.0708
#9, 11
Di sh
Percent Moisture =
Percent Volatiles =
19. 37.
6.57.
Non-Volatile Weight / Unit Area =
Volatile Weight / Unit Area =
0.184 orams/sq in
0.013 grams/sq in
166
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FOULANT ANALYSIS FOR FINE BUBBLE DIFFU3ERS
DIFFUSEF: TYPE: Norton
DIFFUSEF: IDENTIFICATION: Hartford. CT
Dj f fuser Tank 2 Pass 2 #6,?
Removed 5/05/87
Date Tested: 5/09/87
Area Scraped: 19.2 sq in (1/2 o-f the total stone area)
Note - All weights are in grams
Dry weight o-f dish = 43.5532 Dish # - F22
Dish + Fanlant(moist) = 50.9934
Wet Foul ant Weight = 7.4402
Dry Weight(Dish + Foulant) = 47.2787
Dry Foulant Weight = 3.7255
Weight After 550 degC = 46.9154
Non-Volatile Foulant Weight = 3.3622
Fere en t Moisture = 49.97.
Percent Volatiles = 9.8"/.
Non-Volatile Weight / Unit Area = 0.175 grams/sq in
Volatile Weight / Unit Area = O.019 grams/sq in
167
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FOULANT ANALYSIS FOR FINE BUBBLE DIFFUSERS
DIFFUSER TYPE: Norton
DIFFUSER IDENTIFICATION:
Hartford, CT
Diffuser Tank 2 Pass 2 #6,?
Removed 5/05/87
Date Tested: 5/09/87
Area Scraped: 19.2 sq in
Note -All weights are in grams
Dry weight of dish =
Dish + Foulant(moist) =
Wet Foulant Weight =
Dry Weight
-------
FOULANT ANALYSIS FOR FINE BUBBLE DIFFUSERS
DIFFUSER TYPE: Norton
DIFFUSER IDENTIFICATION: Hartford, CT
Diffuser Tank 2 Pass 2 #3.3
Removed 5/05/87
Date Tested: 5/09/87
Area Scraped: 38.5 sq in
Note -All weights are in grams
Dry weight of dish = 42.0200 Dish # - D12
Dish ¦+¦ Foul ant(moist) = 45.3332
Wet Foul ant Weight = 3.3132
Dry Weight(Dish + Foul ant) = 43.7080
Dry Foul ant Weight = 1.6880
Weight After 550 degC = 43.4953
Non-Volatile Foul ant Weight = 1.4753
Percent Moisture = 49.IX
Percent Volatiles = 12.67.
Non-Volatile Weight / Unit Area = 0.038 grams/sq in
Volatile Weight / Unit Area = 0.006 grams/sq in
169
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FOULANT ANALYSIS FOR FINE BUBBLE DIFFUSERS
DIFFUSER TYPE: Norton
DIFFUSER IDENTIFICATION: Hart-ford, CT
Ac i d appli ed.
Diffuser Tk.2, Ps.2, #9,11 This sheet lists values -for the final
analysis, after acid was applied.
Removed 5/05/87
Date Tested: 5/09/87
Area Scraped: 38.5 sq in
Nate -All weights are in grams
Dry weight of dish = 44.8957 Dish # - G!
Dry Weight(Dish + Foul ant) =
Dry Foulant Weight =
Weight After 550 degC =
(Dish + Foulant)
Non-Volatile Foulant Weight =
44.8957
51.0446
6.1489
50.7996
5.9039
Percent Volatiles =
(after acid addition)
Non-Volatile Weight / Unit Area =
Volatile Weight / Unit Area =
4.07.
0.153 grams/sq in
0.00637 grams/sq in
Acid Soluble Analysis
Dry foulant weight
before acid addition =
Dry foulant weight after
acid addition =
7.5587
6.1489
Acid Soluble Weight =
Acid Soluble Percentage =
1.4098
18. 657.
170
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FOULANT ANALYSIS FOR FINE BUBBLE DIFFUSERS
DIFFUSER TYPE: Norton
DIFFUSER IDENTIFICATION: Hart-ford, CT
Aci d appli ed.
Diffuser TV;. 2, F's.2, #6,? This sheet lists values -for the final
analysis, after acid was applied.
Removed 5/05/87
Date Tested! 5/09/87
Area Scraped: 19.2 sq in (1/2 of the total stone area)
Note -All weights are in grams
Dry weight of dish = 43.5532 Dish # - F2:
Dry Weight(Dish + Foulant) = 46.4422
Dry Foulant Weight = 2.8890
Weight After 550 degC = 46.3937
(Dish + Foulant)
Nan-Volatile Foulant Weight ¦ 2.8405
Percent Volatiles = 1.77.
(after acid addition)
Non-Volatile Weight / Unit Area = 0.148 grams/sq in
Volatile Weight / Unit Area = 0.00252 grams/sq in
Acid Soluble Analysis
Dry foulant weight
before acid addition = 3.7255
Dry foulant weight after
acid addition = 2.889
Acid Soluble Weight = 0.8365
Acid Soluble Percentage = 22.45'/.
171
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FOULANT ANALYSIS FOR FINE BUBE
-------
FOULANT ANALYSIS FOR FINE BUBBLE DIFFUSERS
DIFFUSER TYPE: Norton
DIFFUSER IDENTIFICATION: Hartford, CT
Aci d appli ed.
Diffuser Tk.2, Ps.2, #3,3 This sheet lists values for the final
analysis, after acid was applied.
Removed 5/05/87
Date Tested: 5/09/87
Area Scraped: 38.5 sq in
Note - All weights are in grams
Dry weight of dish = 42.0200 Dish # - D12
Dry Weight(Dish + Foul ant) = 42.8057
Dry Foul ant Weight = 0.7857
Weight After 550 degC = 42.7530
(Dish + Foul ant)
Non-Volatile Foul ant Weight = 0.7330
Percent Volatiles = 6.77.
(after acid addition)
Non-Volatile Weight / Unit Area = 0.019 grams/sq in
Volatile Weight / Unit Area = 0.00137 grams/sq in
Acid Soluble Analysis
Dry foul ant weight
before acid addition = 1.688
Dry foulant weight after
acid addition = 0.7B57
Acid Soluble Weight = 0.9023
Acid Soluble Percentage = 53.457.
173
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SUMMARY OF DIFFUSER CHARACTERIZATION DATA
Diffusers Received From: Hart-ford, MDC
Date Received: 5/26/87
Date Diffuser Diff user
Tested Type Condition and Identification Avq. BRV S / x
5/26/87 Norton
CIeaned
#1
15. 2
0. 64
5/26/87 Norton
CIeaned
#2
14.3
0. 78
5/26/87 Norton
CIeaned
#3
11.1
0. 24
5/26/87 Norton
CI ean
#4
6. 1
0. 06
. 5
Cf ID
DWP (in wg.)
.75 1.0
cfm cfm
2. 0
cfm
Rat i o
DWP0.75
BRV
Cleaned #1
7.8
8.3 B. 8
10.6
0. 546
Cleaned #2
6. 5
6.7 6.9
7.7
0. 467
Cleaned #3
7. 1
7.5 7.8
9.4
0. 676
Cleaned #4
5.6
5.8 5.8
6.4
0. 959
Flux Rate
Inner
Flu:; F:ate
Outer
-------
DIFFUBER DESCRIPTIONS
The diffusers were originally tested on 5/26/87.
Retesting was done on 7/01/87, after the diffusers were soaked 20 hrs.
The tops of the stones were relatively clean with only a few fouled
areas. The foul ant was hard, dry, and crusty.
When doing BRV's, the readings were constant until a fouled
area was reached. These areas produced a variety of values. A good
average was put on the data sheets.
The flow on the cleaned stones was uneven. Most of the flow
came from the center or from the seal in the edges.
175
-------
Dif+'user ID: Hart-ford, HDC
Diffuser #1
Descr i pt i on:
FOUL.ANT: The stone was fairly clean. There was some
foul ant present in sparsely located, dark brawn
patches. Some lighter brown material was also
present near the edges.
FLOW: The flow was good, but uneven.
MISC.: The stone was retested on 7/01/87. It was
soaked for 20 hrs. before retesting.
17 6
-------
Diffuser ID: Hartford, MDC
Di ffuser #2
Descr i pt i on:
FOULANT: The top of the stone was fairly clean. A brown
material covered the edges af the stone. Some
was dark and crusty and some was a lighter
brown.
FLOW: The flow was good. On the edges and on the top
the flow was rather sparse.
MISC.: The stone was soaked 20 hrs. before retesting.
177
-------
Diffuser ID: Hartford, MDC
Diffuser #3
Descript i on:
FQULANT: The top of the stone was fairly clean. A black
sooty material covered the edges of the stone.
FLOW: The flow was good near the center of the stone.
On the edges and outer edge of the top the flow
was rather sparse.
MISC.: The stone was soaked 20 hrs. before retesting.
178
-------
Diffuser ID: Hartford, MDC
Diffuser #4
Description:
FDLJLANT: The stone was new.
FLOW: Flow was good and uniform.
MISC.: The stone was soaked 20 hrs. before retestinq.
179
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NORTON/BRAY DOME DIFFUSER CHARACTERIZATION SHEET
DIFFUSER IDENTIFICATION— Hartford, MDC
Diffuser #1
DATE-
5/26/87
LOCATION BRV
# (in H20>
H20 Height
(in H20)
BRV
(in
TOTAL
H20)
4
5
6
7
8
IS
4S
5S
8S
13. 80
10. 50
1 1 . 95
15.80
10. 10
12. 90
18.00
14.95
31.00
18.60
13. 75
40. 00
2.50
2.70
-y '-vcr
• jLU
2. 15
2. 75
3. 00
3. 40
3. 00
2. 00
2. 25
2. 00
0. 00
11.30
7. BO
8. 70
13. 65
7. 35
9. 90
14. 60
11.95
29.00
16.35
1 1 .75
40. 00
/ V =
s /::
10.656
0. 251
TOP
s / =
15.196
0.638
OVERALL
s/;: =
24.275
0.526
SIDES
DWP vs FLOW
ROTO FLOW
RDG (cfm)
DWP
( i n wg)
DWP(actual)
(in wg)
91
2.08
15. 7
10. 7
21
0. 50
12. B
7.8
33
0.75
13.3
8.3
43
1. 00
13.8
8.8
87
2.00
15. 6
10.6
Height of
water above diffuser
=
5.0 in.
FLOW PROFILE (3 bucket catch)
VOLUME
(cc)
TIME
< sec)
TOTAL FLOW
(cc/sec)
ANNULAR FLOW
per sq -ft
(cfm/sq -ft)
TOTAL ANN
FLOW
(cfm)
OUTER
MIDDLE
INNER
10320
600
400
¦9.20
2. 15
3. 80
353. 4
279. 1
105 •
1.50
3.41
4. 89
0. 158
0 . 368
0.223
NOTES—
Total Flow (cfm)
0.749
180
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NORTON/BRAY DOME DIFFUSER CHARACTERIZATION SHEET
DIFFUSER I DENTIFICATION-
Hart-fard, MDC
DATE--
5/26/87
Diffuser
LOCATION
#
BRV
(in H20)
H20 Height
(in H20)
BRV TOTAL
(in H20)
i
4
5
6
7
0
IS
4S
5S
8S
10.70
1.1. 60
24.00
17.20
14.55
12. 00
10.00
10. 85
8. 55
40. 00
9. 75
35. 30
3. 50
4.00
3. 50
25
75
3.60
3. 00
2. 00
0. 00
1.75
1.75
8. 45
8. 10
20.00
13.70
11.30
8. 25
6.40
7. 85
6.55
40. 00
B. 00
s /:: =
10.506
0. 426
TOP
s/:<
14.346
0.782
OVERALL
5 / X —
52.025
0. 783
SIDES
DWP vs FLOW
ROTO
RDG
FLOW
(cf m>
DWP
(in wg)
DWP(actual )
(in wg)
91
21
• j»
43
87
2.08
0.50
0. 75
1. 00
2. 00
12.8
11.5
11.7
11.9
12.7
7.8
6. 5
6.7
6.9
7.7
Height o-f water above dif-fuser
0 in.
FLOW PROFILE (3 bucket catch)
VOLUME
(cc)
TIME
< sec)
TOTAL FLOW
(cc/sec)
ANNULAR FLOW
per sq -ft
(c-fm/sq -ft)
TOTAL ANN
FLOW
(cf m)
OUTER
MIDDLE
INNER
10320
600
400
28. 80
2.90
4.30
358.3
206. 9
93. 0
3.05
2.24
4.32
0.321
0. 241
O. 197
NOTES-
Total Flow (cfm) =
0. 759
181
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NORTON/BRAY DOME DIFFUSER CHARACTERIZATION SHEET
DIFFUSER IDENTIFICATION— Hartford, MDC
Diffuser #3
DATE-
5/26/87
LOCATION BRV
# (in H20)
H20 Height
(in H20)
BRV TOTAL
(in H20)
1
6
7
8
IS
4S
5S
8S
8. 80
14. 95
13. 60
16. SO
1 4. 50
16. 15
14. 20
10.95
9.65
17.10
I 1 . 50
II . 90
1 .85
2. 00
3 • 25
3. 00
2. OO
2. 50
2. 00
2. 00
1.85
2. 00
6. 95
12. 95
10. 35
13. 80
12. 50
13.90
11.95
8.45
7.65
15. 10
9.65
9. 90
s / ;< =
11.356
0.225
TOP
s/:;
11.096 OVERALL
0. 239
s /:•:
10.575 SIDES
0. 301
DWP vs FLOW
ROTO FLOW
F:DG (cfm!
DWP
(i n wy)
DWP(actual)
(in wcj >
91
21
43
87
2. 08
0. 50
0. 75
1. 00
2. 00
14.5
12. 1
12.5
12.8
14.4
7. 1
7.5
7.8
9.4
Height of water above cliff user =
FLOW F'ROFILE (3 bucket catch)
VOLUME
(cc>
TIME
(sec)
TOTAL FLOW
(cc/sec)
5. O i n.
ANNULAR FLOW
per sq -ft
(cfm/sq ft)
TOTAL ANN
FLOW
(cf m)
OUTER
MIDDLE
INNER
NOTES-
10320
600
400
28. 90
4.25
8.20
357. 1
141.2
4B. 8
4.35 0.458
1.81 0.196
2.27 0.103
Total Flow
-------
NORTON/GRAY DOME DIFFUSER CHARACTERIZATION SHEET
DIFFUSF.R IDENTIFICATION— Hartford, MDC
DATE-
5/26/87
Diffuser #4
LOCATION
BRV
(in H20)
H20 Height
(in H20)
BRV TOTAL
(in H20)
6
7
B
IS
45
5S
8S
1 O. 40
11. 00
10. 90
11. OO
10
11
11
11
20
00
15
8. SO
8. 00
8. 15
7. 95
4.25
4.75
4.50
4. 75
4.50
4. 75
4. 70
4. 75
3. 25
nc
2. 50
6.15
6. 25
6. 40
6. 25
5. 85
6. 45
6. 30
6. 40
5.55
5. 75
5.65
5. 60
y. =
6. 256
TOP
S/K =
0. 03.1
x =
6. 050
OVERALL
S / X =
0.057
—
5. 638
BIDES
s /=
0.015
DWF' vs FLOW
ROTO
FLOW
DWF'
DWP(actual)
RDG
(c-f m)
(i n wg)
(i n wq)
91
2.08
11.5
6.5
21
0. 50
1.0. 6
5.6
- j> J'
0.75
10.8
5.8
43
1. 00
10. 8
5. 8
87
2. 00
11.4
6. 4
Height of
water above di-f-fuser =
5.0 in.
FLOW PROFILE (3 bucket catch)
ANNULAR FLOW
VOLUME
TIME
TOTAL FLOW
per sq ft
(cc)
(sec >
(cc/sec)
(cfm/sq ft)
OUTER
10320
29. 40
351. 0
3.61
MIDDLE
600
3.50
171 . 4
1.83
INNER-
400
5. 10
78. 4
3. 65
Total Flow (cfm)
NOTES—
TOTAL ANN
FLOW
(c-f m)
0.381
0. 197
0. 166
0. 744
183
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