EPA 904/9-77-027
TECHNICAL ASSISTANCE PROJECT
AT THE
OWENSBORO WASTEWATER TREATMENT PLANT
OWENSBORO, KENTUCKY
ENVIRONMENTAL PROTECTION AGENCY
SURVEILLANCE AND ANALYSIS DIVISION
ATHENS, GEORGIA
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EPA 904/9-77-027
iV
¦ \y Agency
TECHNICAL ASSISTANCE PROJECT
AT THE
OWENSBORO WASTEWATER TREATMENT PLANT
OWENSBORO, KENTUCKY
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TABLE OF CONTENTS
Introduction 1
Summary . 2
Recommendations 4
Treatment Facility 5
Treatment Process 5
Personnel 5
Study Results and Observations 5
Flow 10
Waste Characteristics and Removal Efficiencies 10
Primary Sedimentation 12
ABF Tower and Aeration Basins 14
Clarithickeners 16
Chlorine Contact Tanks ... 17
Sludge Handling 17
Laboratory 17
References 20
Appendices
A. Laboratory Data
B. Dissolved Oxygen Concentrations
C. Oxygen Uptake Procedures
D. General Study Methods
E. Project Personnel
F. Sludge Blanket Finder
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LIST OF TABLES
I. Design Data . . .. . g
II. Waste Characteristics. 11
III. Primary Clarifier Operational Parameters 12
IV. Secondary Clarifier Operational Parameters 16
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LIST OF FIGURES
1. Owensboro WTP ........... 7
2. Influent pH .¦ 13
3. Average Settlometer Results of the Aeration Basins 15
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INTRODUCTION
A technical assistance study of operation and maintenance problems at the
Owensboro Wastewater Treatment Plant, Owensboro, Kentucky was conducted June 5-10,
1977 by the U. S. Environmental Protection Agency (US-^EPA) , Region IV, Surveillance
and Analysis Division. Operation and maintenance technical assistance studies
are designed to assist wastewater treatment plant personnel in maximizing treatment
efficiencies as well as assisting with special operational problems.
The selection of this plant was based on a request from the Kentucky Department
for Natural Resources and Environmental Protection (KY-DNREP). The study was
coordinated with the U.S. EPA Enforcement and Water Divisions. The specific study
objectives were:
1. To optimize treatment through control testing and recommended operation
and maintenance modifications;
2. To introduce and instruct plant personnel in new operation control
techniques;
3. To determine influent and effluent wastewater characteristics;
4. To assist laboratory personnel with any possible laboratory procedure
problems; and
5. To compare design and current loading data.
A follow-up assessment of plant operation and maintenance practices will be
conducted through utilization of data generated by plant personnel. If necessary,
subsequent visits to the facility will be made. The follow-up assessment will
determine if recommendations were successful in improving plant operations and
if further assistance is required.
The cooperation of the KY-DNREP is gratefully acknowledged. The technical
assistance team is also especially appreciative for the cooperation and assistance
received from personnel of the City of Owensboro, Kentucky, and the Owensboro
Waste Treatment Plant.
1
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SUMMARY
The Owensboro Wastewater Treatment Plant (WTP)_ became operational as a
primary system in 1958. Following expansion and modification the plant evolved
into the existing 12 mgd activated biofilter (ABF) WTP.
During the study period the average influent flow was 8.4 mgd and ranged
from a minimum of 4.0 to a maximum of 13.6 mgd. Total suspended solids and BOD^
reductions during the study were 74 and 72 percent, respectively.
Major observations during the study were:
1. Dissolved oxygen concentrations were extremely low throughout most of the
WTP as evidenced by low electronic DO meter readings and offensive odors.
2. The main lift station was allowed to pump at a high rate for an extended
period of time. Consequently the sewers were bringing into the WTP
septic waste, rags, tin cans, etc.
3. Anaerobic supernatant introduced at the aerated grit chamber was exerting
an added organic load and excessive oxygen demand on the waste treatment
process.
4. The Owensboro WTP was not meeting the NPDES permit weekly average limit
for secondary effluents.
5. Sludge was not being properly conditioned due to breakdown of one
Purifax unit.
6. Conditioned sludge did not dewater properly on the drying beds.
7. The return activated sludge was septic and inactive.
8. Partially treated sludge, rags and other debris piled around the plant
site created a general nuisance condition due to excessive odors and
flies.
9. 'Rags trapped on the bar screen caused wastewater to back-up in the
Parshall flume resulting in erroneous flow recording.
2
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10. There were up to 3 feet of solids accumulated in the final chlorine
contact chamber.
11. There was no means for measuring the secondary waste, sludge flow.
3
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RECOMMENDATIONS
Based on observations and data collected during the study, it is
recommended that the following measures be taken to improve wastewater treat-
ment and plant operations. By observing treatment responses to gradual
process changes, optimum treatment efficiency can be obtained.
1. The septic inactive sludge should be wasted from the secondary
system and a new active sludge developed under aerobic conditions.
A regular wasting schedule should be established and adhered to.
2. Dissolved oxygen concentration in the aeration basins should be
maintained between 1 to 2 mg/1 and monitored regularly with an
electronic DO meter.
3. The services of Neptune-Microfloc (manufacturers of the ABF Tower),
should be obtained to re-establish a satisfactory operational
schedule for the WTP.
4. The storage of poorly digested sludge in the old anaerobic digester
should be discontinued. A concerted effort should be directed to
properly oxidizing the sludge and to utilizing the full capacity of
the drying beds.
5. The collection system lift stations should be controlled to eliminate
septic conditions at the primary clarifiers. The use of chlorination
or oxygenation at the lift station should be explored.
6. Waste sludge flow from the secondary process should be metered.
7. Sludge should not be permitted to remain in the clarithickeners for
excessive periods of time.
8. Settlometer tests and VSS analyses should be run on the overflow from
each aeration basin.
9. The quantity of solids in the aeration basins, return sludge and waste
sludge should be determined once during each shift by centrifuge.
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10. The depth of the sludge blanket below the water surface should be
measured ±11 each clarifier during each shift.
11. Waste and return sludge should be analyzed for TSS and VSS.
12. To optimize treatment, the tests mentioned in recommendations 8
through 11 should be conducted on a routine basis. Coupled with data
already generated by laboratory personnel, trend charts should be
plotted and posted in order to assess responses to operational changes.
Suggested trend chart parameters are F/M, effluent turbidity, return
sludge flow, waste sludge flow (secondary), plant flow, sludge blanket
depth, settlometer (especially 5 and 60 minute readings), return sludge
concentrations (centrifuge), settled sludge concentrations, aeration
basin dissolved oxygen, MLSS, and influent and effluent B0D5, TSS, and
COD.
5
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TREATMENT FACILITY
TREATMENT PROCESS
A schematic diagram of the 12 mgd activated Biological filter (ABF) waste-
water treatment plant (FTP) is shown in Figure 1 and design data are enumerated
in Table I.
The WTP provides wastewater pretreatment by use of bar screen, comminution,
and diffused air grit chamber. Following pretreatment there are three primary
settling tanks. Secondary treatment is provided by an activated biofilter in
series with two parallel aeration tanks followed by two clarithickeners in parallel.
Chlorine is applied to the effluent wastewater prior to two chlorine contact tanks
operated in series. Treated wastewater is discharged into the Ohio River.
Return sludge flows by gravity to a pump collection well, where it is mixed
with primary effluent, and pumped to the ABF tower.
Primary sludge and secondary waste activated sludge is pumped to holding tanks
and subsequently treated by two Purifax sludge conditioning units and dewatered on
eight sludge drying beds. Dewatered sludge is removed and trucked to a landfill.
PERSONNEL
The WTP is staffed by 17 persons which are distributed In three eight hour
shifts. The staff breakdown during the study included one superintendant, three
class b operators, two class 3 operators, four class 1 operators, three unclassified
operators and four laborers.
STUDY RESULTS AND OBSERVATIONS
Prior to the technical assistance study a representative for Neptune-Hicrofloc
(ABF Tower Manufacturers), Mr. Jeff Larsen, was called to assist WTP personnel in
getting the plant under control. After ten days of intensive work Mr. Larsen and
the plant operational staff were successful. According to Mr. Larsen and plant
personnel, a schedule of operations was established which would maintain the
facility in good operating condition.
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FIGURE 1
OWENSBORO WTP
OWENSBORO, KENTUCKY
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FLOW MEASUREMENT
Influent
Primary Settling
Final Settling
Return Sludge
Primary Sludge
Purifax Conditioner
Design Flow
Peak Flow
GRIT CHAMBER
Type
PRIMARY SETTLING
Number of tanks
Length
Width
Depth (SW)
Area
Volume
Detention Time
ABF TOWER
Number of Sections
Volume (per section)
Total
Lift Station
Pumps
BOD Loading
AERATION BASINS
Number Units
Volume
Total
Aeration (each basin)
Detention Time
TABLE I
DESIGN DATA
OWENSBORO WTP
OWENSBORO, KENTUCKY
One-3 foot Parshall flume
Three - 1 foot Parshall flumes
Two - 2 foot Parshall flumes
Magnetic flow meter
Magnetic flow meter
Magnetic flow meter
12 mgd
16 mgd
Diffused air, bucket removal with
manual disposal
Three-rectangular
120 feet
40 feet
8 feet
4,800 sq.ft. each
38,400 cu.ft. each
286,000 gallons
1.5 hours @ 12 mgd
Eight
13,800 cu.ft.
110,00 cu.ft. 822,800 gallons
Four constant speed rated 0 9,200 GPM
84.15 lbs/1000 cu.ft.
Two-rectangular
473,000 gallons each
946,000 gallons
Two - 7.5 HP, Slow Speed
Fixed meahanical aerators
3.8 hours @ 12 mgd
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TABLE I - Continued
CLARITHICKENERS
Number
Diameter
Depth (SW)
Area
Volume
Weir Length
Weir Overflow Rate
Detention Time
CHLORINE CONTACT TANK
Number
Volume
Old
New
Detention Time
PURIFAX SYSTEM
Number
Total Capacity
DIGESTER
Two-circular center feed
rim take-off
120 feet
8 feet
11,300 sq.ft.
90,430 cu.ft.
676,000 gallons
377 feet
16,000 gpd/ft.
2.7 hrs @ 12 mgd
Two-rectangular
Number
Volume
Utilization
120,000 gallons
530,000 gallons
1 hr. @ 12 mgd
Two units
150 GPM
One
140,000 cu.ft.
Sludge holding
DRYING BEDS
Number
Type
Area (each)
Eight-rectangular
Two-sand filled with conrete drives
Six-concrete filled with sand drainage
strips.
6,000 sq.ft.
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A complete listing of all analytical data and general study methods are
presented in the Appendices. Significant results and observations made during
the study are discussed in the following sections.
FLOW
Influent wastewater flow was measured with a three foot Parshall flume
equipped with a recorder and totalizer. The three foot influent flume was checked
and found to be in reasonable agreement with the recorder in the control building
(7.5 mgd to 7.8 mgd). Problems were noted however, with the construction of the
influent flume and the three primary effluent flumes. The three foot influent
flume was found to have a throat width on the downstream side of 3.12 feet and
3.03 feet on the upstream side. Throat widths for the one foot primary clarifier
flumes ranged in width from 0.83 feet to 1.10 feet. These variations obviously
introduces a degree of error into the discharge reading. In addition rags along
with other debris were caught in the bar screen and restricted the flow causing
backwater in the throat of the influent flume producing erroneous flow recordings.
Average influent flow during the study period was approximately 8.4 mgd and ranged
from 4 to 13.6 mgd.
Return sludge flows (RSF) were measured with magnetic flow meters equipped
with recorders and totalizers. Average return sludge flow during the study was
3.82 mgd (45 percent of plant flow) and ranged from 2.6 to 4.4 mgd.
Waste activated sludge flows from the secondary process could not be measured,
but primary sludge flow was measured with a magnetic flow meter equipped with a
recorder and totalizer. Waste primary sludge flow during the study averaged
0.046 mgd for the three day period.
WASTE CHARACTERISTICS AND REMOVAL EFFICIENCIES
Table II presents a chemical description of the influent and effluent waste-
waters with calculated treatment reductions. Removal efficiencies were calculated
using average data from three consecutive 24-hour flow proportional samples.
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TABLE II
WASTE CHARACTERISTICS AND REMOVAL EFFICIENCIES
OWENSBORO WTP
PRIMARY
INFLUENT
EFFLUENT
PRIMARY
EFFLUENT
PLANT
PARAMETER
(mg/1)
(mg/1)
% REDUCTION
(mg/1)
% reduct:
bod5
233
277
- 2.6
66
72
COD
496
426
14
158
68
TOC
146
167
-14
42
71
TS
721
-
-
596
17
TVS
305
-
-
208
32
TSS
192
139
28
49
74
VSS
141
86
39
41
71
TKN-N
23
22
4
20
13
nh3-n
17
17
0
16
6
NO3-NO2-N
0.34
0.17
50
.04
88
TOTAL-P
8.7
9.9
-14
8.4
3
Pb
<0.115
-
-
<0.08
-
Cr
<0.119
-
-
<0.100
-
Cu
0.093
-
-
0.029
69
Cd
<0.01
-
-
<0.01
-
Zn
0.217
-
-
0.090
59
CI2 Residual
-
-
-
1.42
-
The WTP was designed to treat 16,900 lbs/day of BOD^ and TSS at 12 mgd with
a removal efficiency of 89 percent. During the study the B0D5 and TSS loading on
the WTP were 16,320 and 13,450 lbs/day, respectively, at 8.4 mgd.
Removal efficiency during the study was only 72 and 74 percent for BOD^ and
TSS, respectively. Approximately 69 and 45 percent of this removal was accomplished
through the filter alone. As a result of these low removal rates 4^600 lbs/day of
BOD5 and 3,400 lbs/day of TSS were being discharged into the receiving stream.
These B0D5 and TSS discharge rates exceeded the NPDES permit limits by 35 and 12 percent,
and exceeded design limits by 57 and 42 percent, respectively.
According to data shown in Table II, nitrification was not being achieved by
the treatment system, (TKN and NH^-N remained essentially unchanged). Nitrate-nitrite
nitrogen (N03-N02-N) concentrations showed a substantial reduction in both the
primary and the secondary system (88 percent). This reduction due to denitrification
was expected since most of the WTP system was anaerobic.
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From these data it can be concluded that the WTP was not hydraulically
or organically overloaded however, NPDES permit limits were not being met.
PRIMARY SEDIMENTATION
The primary sedimentation system consisted of three 286,000 gallon
rectangular basins. Wastewaters entering the basins were highly septic due
to the anaerobic condition of the raw waste and to introduction of the sludge
holding tank "supernatant" into the grit chamber. The periods of supernatant
return are clearly evident in Figure 2 as indicated by the corresponding pH
drops The COD TKN and NH3-N concentrations of the supernatant stream were
44 771 mg/1, 475 mg/1 and 115 rag/1, respectively. Average BOD5 and TSS reductions
combination of the septic waste and strong side stream return produced an
undesirable condition in the primary units and a heavy immediate oxygen demand on
the secondary system.
through the primary
clarifiers were -2.6 and 28 percent, respectively. The
In Table III are
listed several calculated, design and recommended operational
parameters for the primary system.
TABLE III
PRIMARY CLARIFIER OPERATIONAL PARAMETERS
0WENSB0R0, KENTUCKY
Measured Design
Recommended (1)(3)(9)
Hydraulic Detention
Time (h«
Hydraulic Loading
(hrs)
583
1.6
833
1.2
600 - 1,200
1-2
(gpd/sq.ft.)
Solids Loading
0.93
1.2
(lbs/day/sq.ft.)
12
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PH
12 "
8 ~
4
12"
8
4
12"
8 -=]
06/06/77
MON
06/07/77
TUE
08/08/77
WED
4 1
12-
8
06/09/77
THUR
FIGURE 2
INFLUENT pH
OWENSBORO,KY. NTP
TIME CHRS)
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ABF TOWER AND AERATION BASINS
The major problem with these units was the completely septic conditions of
the contents of the aeration basins (Appendix B). Dissolved oxygen was present
(approximately 6 mg/1) in the ABF tower effluent, however, it was depleted
immediately upon entering the aeration basins. This problem was caused by
improper operation of the sludge loop. Sludge was permitted to remain for long
periods of time in the clarithickeners before being returned to the tower or
wasted. The septic sludge imposed an immediate oxygen demand on the tower. The
effluent from the tower was not sufficiently stabilized for the small aerators
in the aeration basin to maintain aerobic conditions. Thus the sludge was in
a completely septic environment except for the few seconds that it took to fall
through the tower.
Grab samples were collected daily from each aeration basin and analyzed for
total suspended solids (TSS), volatile suspended solids (VSS), percent solids by
centrifuge, and settleability as determined by the settlometer. The results of
these tests (Appendix A) show a very rapidly settling, poor quality sludge which
left a turbid septic supernatant (Figure 3).
The oxygen uptake test is helpful in evaluating sludge activity. This
activity is measured by mixing return activated sludge with influent (fed) and
nonchlorinated effluent (unfed) wastewater and determining the uptake rate, from
which the load ratio (LR) is calculated.
Load Ratio = ADO (mg/l/min) fed sludge
ADO (mg/l/min) unfed sludge
The detailed procedure for this test is contained in Appendix C. Generally,
in conventional activated sludge plants, a load ratio from 2 to 4 signifies an
abundant, acceptable feed under favorable conditions. A small LR (<2) may mean
dilute feed, sick sludge, poorly acceptable feed, or other unfavorable conditions.
A LR less than 1.0 indicates inhibitory or toxic effects from the wastewater producing
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FIGURE 3
AVERAGE SETTLOMETER RESULT OF THE AERATION BASINS
OWENSBORO, WTP
OWENSBORO, KENTUCKY
SO
15
20 30
TIME (min)
10
50
60
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a reduced "bug" activity rate. A LR greater than 4 usually indicates a young
under-oxidized sludge which may bulk.
A considerable amount of information can be obtained from the uptake tests
at the Owensboro WTP. First the septic conditions of the plant influent, the sludge
holding tank supernatant and the return sludge created a tremendous oxygen deficit
(chemical oxygen demand) which must be satisfied immediately and before any aerobic
biodegradation of the waste can occur. Dissolved oxygen measurements in the aeration
basins and clarithickeners showed that the oxygen deficit was never satisfied.
The uptake rate of the unfed sample, consisting of return sludge and final
clarified effluent was 1.3 mg of (^/l/min. The fed sample, containing return sludge
and primary clarifier effluent, had a very rapid initial uptake which decreased
to near the unfed rate in about 7 minutes. Initially the uptake rate was 4.3 mg
of C^/l/min. After reaeration the rate dropped to 2.8 mg of (^/l/min and subsequently
down to 1.4 mg of C^/l/min on the next run. These results show that it was essentially
impossible to supply adequate oxygen to the septic waste initially and that the sludge
was inactive. Biological examinations verified that the sludge was inactive.
The highly septic conditions of the primary effluent should be eliminated by
better control of collection system lift stations, chlorination or oxygenation at
collection system lift stations and better control of the supernatant return to the
primary. A better quality sludge should be developed by gradually wasting most
of the sludge currently in the system and building new sludge under aerobic conditions.
Sludge should not be permitted to remain in the clarifier for excessive periods of
time. It may be beneficial to by-pass the aeration basins with a major portion of
the waste since the tower is the primary air source. Tower recirculation rates
and sludge return rates may have to be stepped up temporarily. Air in excess of
the amount normally needed for biodegradation of the organic material and respiration
of the organisms must be supplied to break the septic sludge cycle. The additional
16
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air is required to oxidize chemical compounds formed under previously existing
anaerobic conditions. In order to get the WTP operating properly dissolved
oxygen should be closely monitored and maintained at a minimum of 1.0 - 2.0 mg/1.
CLARITHICKENERS
Final settling at the WTP was provided by two 676,000 gallon clarithickeners
having a center feed, rim take-off configuration. Measured and recommended operating
parameters for secondary clarifiers following the activated sludge process are
presented in Table IV.
TABLE IV
SECONDARY CLARIFIER OPERATIONAL PARAMETERS
0WENSB0R0, KENTUCKY
Measured Design Recommended(1)(4)(8)
Hydraulic Detention Time (hrs) 2.66 1.86*(2.7) 2-3
Hydraulic Loading (gpd/sq.ft.) 372 530 300 - 1,200
Solids Loading (lbs/day/sq.ft.) 11 - 12 - 30
Weir Overflow Rate (gpd/ft.) 11,140 16,000 5,000 - 20,000
Depth (ft.) 8 8 10-15
( ) - Detention time @ 12 mgd without return sludge.
* - Detention Time @ 12 mgd plus 45 percent return sludge.
All operational parameters for the clarithickeners were within design and
recommended criteria. The recommended criteria are for clarifiers following the
conventional activated sludge process. The differences between regular clarifiers
and clarithickeners are, depth of the sludge blanket and the length of sludge
retention time. Sludge is permitted to remain in the center well for longer
periods of time so that a thicker sludge can be wasted from the system. This
system is used in lieu of separate clarifiers and sludge thickeners.
Highly chlorinated water from the head of the contact chamber was pumped back
to the clarithickeners influent wells to aid in odor control. The recirculated
chlorinated effluent flow averaged 0.65 mgd and ranged from 0.363 to 1.21 mgd
during the study period. These figures were obtained by determining
differences in influent and clarifier Parshall flume measurements.
17
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CHLORINE CONTACT TANKS
Effluent from the clarithickeners was disinfected in two chlorine contact
chambers (CCC) operated in series before discharging into the Ohio River.
Detention time in the CCCs was approximately 1 hr. and 52 minutes at the
average study flow of 8.4 mgd. The total chlorine residual during the study
ranged from 0.80 to 1.8 mg/1 based on the amperometric back titration method.
Bubbles and small clumps of solids were observed rising to the water
surface in the CCC. Depth measurements utilizing the sludge blanket finder
showed that up to 3 feet of solids were deposited along the sides of the channel.
The deepest solids deposition (3 feet) was measured in the outlet channel.
SLUDGE HANDLING
Primary and waste activated sludge flows to a sump from which it is pumped
through two Purifax sludge treatment units. Numerous mechanical and operational
problems have been encountered since startup of these units and adequate sludge
treatment has not been accomplished. During the study treated and/or partially
treated sludge was stored in the old abandoned anaerobic digester. The super-
natant which had extremely high total solids (37,392 mg/1) and COD (44,771 mg/1)
concentrations placed an added oxygen demand on the plant. A problem also exist
in disposing of this backlog of sludge. The volatile content of the solids was
73 percent indicating that the material will not dewater well on the drying beds.
Six of the eight drying beds have a sloping concrete bed with a narrow sand
drain down the center. The other two are sand beds. According to plant personnel,
numerous problems have been encountered in dewatering the sludge. Possible causes
of the problem may be inadequately digested sludge, poor bed drains, poor quality
sand and etc. Six of the eight beds were clean, drying conditions were excellent
and inadequately digested sludge was accumulating at the plant.
LABORATORY
The laboratory is located in the main control building and was staffed by
two laboratory technicians during the day shift and a laboratory assistant during
18
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the night shift. The following routine analyses were conducted: BOD^, COD,
TS, TSS, settleable solids, fecal coliform, DO, pH temperature, and chlorine
residual. The laboratory was clean, adequate in size, and well equipped.
While at the WTP various analytical procedures were discussed, and the
following observations were specifically made:
1. Sodium thiosulfate titrant, which was used in calibrating the DO
probe, was not being standardized. The importance of standardization
was discussed and the technique demonstrated by EPA personnel.
2. BOD^ calculations were made on samples with DO depletions outside
Standard Methods (7) recommended range of 40 to 70 percent.
3. The orthotolidine method was used in determining residual chlorine
in the plant effluent. Laboratory personnel stated that they had an
amperometrlc bhlorine titrator but that it was inoperable.
The titrator was checked and standardized by EPA personnel and
was working satisfactorily by the end of the study. It was pointed
out that Standard Methods (7) recommends the amperometrlc back
titration procedure in determining chlorine residual in wastewater.
4. The laboratory had an operable muffle furnace, but the volatile
suspended solids analysis was not being conducted. Volatile suspended
solids concentrations are useful in various loading calculations and
in determining the organic and biological content of the mix liquor
and return sludge.
The in-plant control testing program included aeration basin TSS, DO
(surface), and SVI. It was suggested that the following tests also be included
in their program: (1) settlometer in place of the graduated cylinder since the
settlometer better represents clarifier conditions; (2) clarifier sludge blanket
depth; (3) aeration basin DO at various depths (it was suggested that a DO field
probe would facilitate this test); and (4) centrifuge. The centrifuge test
19
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gives a quick indication as to the solid content in the aeration basins and
whether or not the basins are receiving equal loadings. It was further
suggested that trend charts be established and maintained. Useful parameters
for plotting include MLSS, sludge settleability, significant influent and
effluent waste characteristics, flow (plant, return sludge, waste sludge),
depth of clarifier sludge blanket, and MCRT. Experience will dictate which
of these parameters are necessary for successful plant operation. These
suggested parameters should serve only as a guide and are intended to establish
trends so that gradual changes in plant conditions can be noticed prior to
deterioration in effluent quality.
20
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REFERENCES
1. "Operation of Wastewater Treatment Plants", A Field Study Training Program,
US-EPA, Technical Training Grant No-5TTl-WP-16-03, 1970.
2. "Process Design Manual for Suspended Solids Removal", US-EPA Technology
Transfer, January 1975.
3. "Sewage Treatment Plant. Design", American Society of Civil Engineers,
Manual of Engineering Practice No. 36, 1959.
4. "Wastewater Engineering", Metcalf and Eddy, Inc., 1972.
5. West, Alfred W., Operational Control Procedures for the Activated Sludge
Process. Part I., Observations, EPA-330/9-74-001-a, April 1973.
6. "Recommended Standards for Sewage Works", Great Lakes - Upper Mississippi
River Board of State Sanitary Engineers, Revised Edition, 1971.
7. "Standard Methods for the Examination of Water and Wastewater," 13th Edition,
1971.
8. "Process Design Manual for Upgrading Existing Wastewater Treatment Plants",
US-EPA Technology Transfer, October 1974.
9. Parker, Homer W., Wastewater Systems Engineering, 1975.
21
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APPENDIX A
LABORATORY DATA
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APPENDIX A
LABORATORY DATA
OWENSBORO WTP
OWENSBORO, KY
INFLUENT, PRIMARY EFFLUENT, TOWER EFFLUENT, AND PLANT EFFLUENT
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-------
APPENDIX A
LABORATORY DATA
OWENSBORO WTP
OWENSBORO, KY
AERATION BASINS, RETURN SLDDGE, WASTE SLUDGE, PURIFAX SLUDGE, AND PRIMARY SLUDGE
-------
APPENDIX A
LABORATORY DATA
OWENSBORO, WTP
OWENSBORO, KY
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-------
APPENDIX B
DISSOLVED OXYGEN CONCENTRATIONS
-------
APPENDIX B
DISSOLVED OXYGEN CONCENTRATIONS
DO mg/1 D0 mg/1
STATION DATE TEMP (°C) 1 ft. DATE TEMP (°C) 1 ft.
AB1 6-6-77 23.5 0.1 6-7-77 22.0 0.1
AB2 23.5 0.0 22.0 0.0
AB3 23.5 0.0 22.0 0.0
AB4 23.5 0.0
AB5 23.5 0.0
AB6 23.5 0.0
AB7
AB8
AB9
AB10
01 24.0 0.7 23.0 0.5
OGCE 24.0 1.1 23.0. 1.0
OPE 24.0 0.1 23.0 0.0
OC2 24.0 0.0 22.0 0.0
ORS2 24.0 0.0 22.0 0.0
OFE 23.5 5.8 22.0 6.1
OCI 24.0 0.0 22.0 0.0
OCE 24.0 3.1 22^0 3.0
OE 24.0 2.8 22.0 2.8
OGCE - Grit Chamber Effluent
OFE - ABF Tower Effluent
-------
STATION
APPENDIX B (Con.
DATE TEMP (°C)
DO mg/1
1 ft.
AB1
6-8-77
21.5
0.
AB2
21.5
0.
AB3
21.5
0.
AB4
21.5
0.
AB5
21.5
0.
AB6
21.5
0.
AB7
21.5
5.
AB8
21.5
4.
AB9
21.5
2.
ABIO
21.5
3.
01
22.0
0.
OGCE
22.0
0.
OPE
23.0
0.
0 C2
22.0
0.
0RS2
22.0
0.
22.0
0.
OFE
22.0
6.
OCI
22.0
0.
OCE
22.0
2.
OE
21.0
2.
1
1
2
2
1
1
1
6
2
7
4
9
1
0
0
0
1
0
4
3
-------
AERATION BASINS
DO PROFILE STATIONS
OWENSBORO WTP
m AB 10"
^4 AlT 5 AE^I
Aerator
Aerator
AB 9
-------
APPENDIX C
OXYGEN UPTAKE PROCEDURES
-------
APPENDIX C
OXYGEN UPTAKE PROCEDURE
A. Apparatus
1. Electronic DO analyzer and bottle probe
2. Magnetic stirrer
3. Standard BOD bottles (3 or more)
4. Three wide mouth sampling containers (approx. 1 liter each)
5. DO titration assembly for instrument calibration
6. Graduated cylinder (250 ml)
7. Adapter for connecting two BOD bottles
B. Procedure
1. Collect samples of return sludge, aerator influent and final clarifier
overflow. Aerate the return sludge sample promptly.
2. Mix the return sludge and measure that quantity for addition to 300
ml BOD bottle that corresponds to the return sludge proportion of the
plant aerator, i.e. for a 40% return sludge percentage in the plant the
amount added to the test BOD bottle is:
300 X .4 _ 120
1.0 + .4 " 1.4 = 86 ml
3. Carefully add final clarifier overflow to fill the BOD bottle and to
dilute the return sludge to the plant aerator mixed liquor solids
concentration.
4. Connect the filled bottle and an empty BOD bottle with the BOD bottle
adapter. Invert the combination and shake vigorously while transferring
the contents. Reinvert and shake again while returning the sample
to the original test bottle. The sample should now be well mixed and
have a high DO.
-------
APPENDIX (Continued)
5. Insert a magnetic stirrer bar and the previously calibrated DO
probe. Place on a magnetic stirrer and adjust agitation to maintain
a good solids suspension.
6. Read sample temperature and DO at test time (t=). Read and record
the DO again at 1 minute intervals until at least three consistent
readings for the change in DO per minute are obtained (ADO/min). Check
for the final sample temperature. This approximates sludge activity
in terms of oxygen use after stabilization of the sludge during aeration
(unfed sludge activity).
7. Repeat steps 2 through 6 on a replicate sample of return sludge that
has been diluted with aerator influent (fed mixture) rather than final
effluent. This A DO/minute series reflects sludge activity after mixing
with the new feed. The test results indicate the degree of sludge
stabilization and the effect of the influent waste upon that sludge.
The load factor (LF), a derived figure, is helpful in evaluating sludge
activity. It is calculated by dividing the DO/min of fed sludge by the DO/tnin
of the unfed return sludge. The load ratio reflects the conditions at the
beginning and end of aeration. Generally, a large factor means abundant,
accepatble feed under favorable conditions. A small LF means dilute feed,
incipient toxicity, or unfavorable conditions. A negative LR indicates that
something in the wastewater shocked or poisoned the "bugs".
1/ Taken from "Dissolved Oxygen Testing Procedure, "F.J. Ludzack and script
for slide tape XT-43 (Dissolved Oxygen Analysis - Activated Sludge Control
Testing) prepared by F.J. Ludzack, NERC, Cincinnati.
-------
APPENDIX D
GENERAL STUDY METHODS
-------
APPENDIX D
GENERAL STUDY METHODS
Methods used to accomplish the stated objective Included extensive sampling,
physical measurements and daily observations. ISCO Model 1392-X automatic
samplers were installed on the influent, primary effluent, and final effluent
streams, and operated three consecutive 24-hour periods. Aliquots of sample
were pumped at hourly intervals into individual refrigerated glass bottles which
were composited proportional to flow at the end of each sampling period. Influent
grab samples were also taken for oil and grease.
Influent and return sludge flows were determined from plant totalizers and
recorders. All dissolved oxygen measurements were determined using the YSI
Model 51A dissolved oxygen meter. An Analytical Measurements Model 30 WP
cordless pH recorder was installed following the Parshall flume to monitor
influent pH throughout the sampling periods. Temperatures and pH were determined
at other stations with therometer and portable pH meter. Depth of the second
clarifier sludge blankets were determined daily using equipment suggested by
Aired W. West, EPA, NFIC, Cincinnati (Appendix F). Sludge activity was
determined by the oxygen uptake procedure presented in Appendix C.
A series of standard operational control tests were run daily;
(1) Settleability of mixed liquor suspended solids (MLSS)
as determined by the settlometer test;
(2) Percent solids of the mixed liquor and return sludge determined by
centrifuge;
(3) Suspended solids and volatile suspended solids analysis on the
aeration basin mixed liquor and return sludge and
(4) Turbidity of each final clarifier effluent.
-------
APPENDIX (Continued)
Daily effluent total chlorine residual concentrations were determined
using an amperometric titrator (Fischer and Porter Model 1771010)
The procedure for the BOD5 determination deviated from Standard Methods (7).
Samples were set up and returned to Athens, Georgia in an incubator wherre the
analyses were completed.
Visual observations of individual unit processes were recorded.
Mention of trade names or commercial products does not constitute endorsement
or recommendation for use by the Environmental Protection Agency.
-------
APPENDIX E
PROJECT PERSONNEL
-------
APPENDIX E
PROJECT PERSONNEL
Charles Sweatt
Herbert Barden
Lavon RevelIs
Eddie Shollenberger
Tom Sack
Engineer
Microbiologist
Chfetaist
Tefchilician
Technician
-------
APPENDIX F
SLUDGE' BLANKET FINDER
-------
APPENDIX f
SLUDGE BLANKET FINDER
Single Pole
Toggle Switch
6 Volt Battery
w/Screw Terminals
(Use Taps or Hose Clamps
to Secure Switch and
Battery to Pole)
Distinctive 10ft Marker
1&n. Schedule 40
Aluminum Pipe
Distinctive 5ft Marker
Place Tape on 0.5ft
and 1.0ft Intervals
to Hold Wire and Aid
in Determining DOB
Wires to Battery
and Switch
SEE DETAIL
154in Schedule_40 Aluminum ^
(Smaller Size May Be Used or.
Short Blanket Finders)
Radiator Hose Clamp
Aluminum U-Strap
Threaded
154 Pipe Coupling
Radiator Hose Clamp
Threaded Site Glass Assembly
("Gitz" or Equal)
Bulb and Socket
From Cannibalized Flashlight
Epoxy Cement
------- |