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Lessons Learned in Enhanced Biological Phosphorus Removal
87th OWEA Annual Conference
Jim Gagnon, P.E., CH2M HILL
V1.0
Presentation Outline
Phosphorus Limits in Ohio
Upgrades to the Versailles, OH WWRF
WWRF Performance
EBPR Basics
11 Lessons Learned from Versailles
Where is Versailles Located?
Southwestern Ohio
Darke County (borders Indiana)
43 miles north of Dayton
Population: ~2,700
Phosphorus Limits in Ohio
Reduced in-stream phosphorus
Reduced aquatic plant growth
• Reduced in-stream
nitrogen and carbon
• Increased dissolved
oxygen
Impact of Stillwater River Basin 2009 TMDL Report
0.17
0.05
0
0.05
0.1
0.15
0.2
TP
(m
g/l
)
2004 TMDL
Report
2009 TMDL
Report
Ambient Target Total Phosphorus
(TP) Concentrations in Swamp Creek
For Village of Versailles…
• Point source controls
• Reduce Total
Phosphorus (TP)…
• Initial effluent TP limit of
1.0 mg/l
Upgrades to Versailles WWRF
Project Drivers:
• Effluent Total Phosphorus Limit of 1.0 mg/l
• Reduce/Eliminate Effluent Blending
** Plant experienced 32 excess flow diversions on
average per year (2003-2007)
Upgrades to Versailles WWRF
Upgrades to Versailles WWRF
New Oxidation Ditch Enhances
Secondary Treatment
Features:
• Provides EBPR/BNR
capability
• Separate, dedicated
anaerobic and anoxic zones
• D.O. control of aerators
• New chemical feed system
• Room for future 2nd ditch
Versailles WWRF Performance, or…
Let the Data Show…
0.0
1.0
2.0
3.0
4.0
2010 2011 2012 2013
3.26
2.36
0.75 0.66
TP
(m
g/l)
Average Effluent Total Phosphorus (TP) Concentration
(Through April 16)
Enhanced Biological P Removal (EBPR) Basics
• Removal of P exceeding metabolic requirements
Enhanced Biological P Removal (EBPR)
Luxury P Removal
Excess P Removal
Bio-P Removal
• Mediated by specialized heterotrophs called
Phosphorus Accumulating Organisms (PAOs)
Anaerobic Zone DO, NO3
Aerobic (DO)
P Release
PHB
Polyphosphate
CO2 + H2O O2
Cell
Synthesis
Energy (Ed)
Excess
P Uptake
PHB: Poly-β-hydroxybutyrate
Rapidly
Biodegradable
Substrate (VFAs)
PHB
Poly-
phosphate
Energy (Ei)
Enhanced Biological P Removal (EBPR) Mechanism
EBPR Mechanism
Aerobic Anaerobic
• VFA uptake &
storage
• P release
• Stored ‘Food’
oxidized
• Excess P Uptake
• Cell synthesis
Waste Sludge
Loaded with P
Starving
(Battery discharging)
Feeding
(Battery charging)
RAS
Anaerobic Aerobic
Ortho-P
3 x Infl. Ortho-P
BOD PHB
Storage
BOD Oxidized
Concentrations
in Bioreactor
Location in Bioreactor
Net P
Removal
Anaerobic/Oxic (A/O) Process Configuration
Lesson 1: Multiple Anaerobic Zones Give PAOs Best Opportunity to Function
• Well-mixed
• Constructed walls
• Single compartment with
baffles
• Provide adequate HRT
Lesson 2: Solids Retention Time Control Provides More Complete Picture than MLSS Control
BIOREACTOR
MLSS QINF QEFF
QWAS, CRAS
= QINF - QWAS VBIOREACTOR
VBIOREACTOR x MLSS
SRT x CRAS QWAS =
Target SRT
EBPR
SRT NITRIFICATION
SRT
Lesson 2: Solids Retention Time Control Provides More Complete Picture than MLSS Control
Lesson 3: Maintain Integrity of Anaerobic Zone to Promote PAO Growth
Anaerobic zone is crucial for PAO selection
Need to ensure
Lesson 4: Maintain Low D.O. in the Aerobic Basin to Promote Denitrification
AERATOR
D.O. TRANSMITTER D.O. PROBE
Lesson 5: Maintain Low Sludge Blankets to Limit Phosphorus in Clarifiers
TELESCOPING VALVE
SLUDGE DRAWOFF
PIPES
• New tank volume of
640,000 gal
• Retained 3 existing
digesters
• Limit anaerobic conditions
during decant
• Decant small volumes
directly to the aerobic
zone of oxidation ditch
Lesson 6: Operate Aerobic Digester to Limit Phosphorus Release
Lesson 7: Use ORP to Monitor Aerobic Digester
DIGESTER ORP AND
D.O. PROBES WITH
FLOAT
Lesson 8: Monitor and Handle Wet Weather Flows to Maintain EBPR
• Wet weather flows:
Dilute in substrate
Higher in DO
• Existing ditch and
clarifiers reused to
provide wet weather
storage
Lesson 9: Prepare for Excursions
• Adsorption
• Ion exchange
• Membrane filtration
• Filtration
• Enhanced (ballasted)
sedimentation
• Chemical addition
Lesson 9: Prepare for Excursions
ALUM STORAGE ALUM DOSING POINT –
OXIDATION DITCH
EFFLUENT WEIR
Lesson 10: Maintain Records and Use Data to Understand How EBPR is Operating
Influent:
Volume, D.O., pH, SS, CBOD5, NH3
Bioreactor:
D.O., pH, MLSS, SVI, MLVSS, F/M
Return Sludge:
pH, SS, Volume Wasted, % Solids, % VS
Effluent:
pH, D.O., NH3, SS, CBOD5, TN, TP
Digesters:
% solids, % VS
Digester Supernate:
NH3, CBOD5, ORP, TP, Volume
Lesson 10: Maintain Records
0
2,000
4,000
6,000
8,000
10,000
12,000
0
5
10
15
20
25
1-M
ar
2-M
ar
3-M
ar
4-M
ar
5-M
ar
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ar
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ar
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ar
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ar
10-M
ar
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ar
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ar
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ar
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ar
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ar
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ar
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ar
18-M
ar
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ar
20-M
ar
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ar
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ar
23-M
ar
24-M
ar
25-M
ar
26-M
ar
27-M
ar
28-M
ar
29-M
ar
30-M
ar
31-M
ar
WA
S o
r D
EC
AN
T (
ga
llo
ns)
SR
T (
da
ys
) o
r To
tal-
P (
mg
/l)
WAS
TARGET SRT = 20 DAYS
March 2013 Data
Lesson 10: Maintain Records
0
2,000
4,000
6,000
8,000
10,000
12,000
0
5
10
15
20
25
1-M
ar
2-M
ar
3-M
ar
4-M
ar
5-M
ar
6-M
ar
7-M
ar
8-M
ar
9-M
ar
10-M
ar
11-M
ar
12-M
ar
13-M
ar
14-M
ar
15-M
ar
16-M
ar
17-M
ar
18-M
ar
19-M
ar
20-M
ar
21-M
ar
22-M
ar
23-M
ar
24-M
ar
25-M
ar
26-M
ar
27-M
ar
28-M
ar
29-M
ar
30-M
ar
31-M
ar
WA
S o
r D
EC
AN
T (
ga
llo
ns)
SR
T (
da
ys
) o
r To
tal-
P (
mg
/l)
WAS SRT-7DMA
TARGET SRT = 20 DAYS
March 2013 Data
Lesson 10: Maintain Records
0.29 0.52 0.97 0.46 0
2,000
4,000
6,000
8,000
10,000
12,000
0
5
10
15
20
25
1-M
ar
2-M
ar
3-M
ar
4-M
ar
5-M
ar
6-M
ar
7-M
ar
8-M
ar
9-M
ar
10-M
ar
11-M
ar
12-M
ar
13-M
ar
14-M
ar
15-M
ar
16-M
ar
17-M
ar
18-M
ar
19-M
ar
20-M
ar
21-M
ar
22-M
ar
23-M
ar
24-M
ar
25-M
ar
26-M
ar
27-M
ar
28-M
ar
29-M
ar
30-M
ar
31-M
ar
WA
S o
r D
EC
AN
T (
ga
llo
ns)
SR
T (
da
ys
) o
r To
tal-
P (
mg
/l)
WAS Total-P SRT-7DMA
TARGET SRT = 20 DAYS
March 2013 Data
Lesson 10: Maintain Records
0.29 0.52 0.97 0.46
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
0
5
10
15
20
25
1-M
ar
2-M
ar
3-M
ar
4-M
ar
5-M
ar
6-M
ar
7-M
ar
8-M
ar
9-M
ar
10-M
ar
11-M
ar
12-M
ar
13-M
ar
14-M
ar
15-M
ar
16-M
ar
17-M
ar
18-M
ar
19-M
ar
20-M
ar
21-M
ar
22-M
ar
23-M
ar
24-M
ar
25-M
ar
26-M
ar
27-M
ar
28-M
ar
29-M
ar
30-M
ar
31-M
ar
WA
S o
r D
EC
AN
T (
ga
llo
ns)
SR
T (
da
ys
) o
r To
tal-
P (
mg
/l)
WAS Total-P SRT-7DMA
TARGET SRT = 20 DAYS
March 2013 Data
Lesson 10: Maintain Records
0.29 0.52 0.97 0.46
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
0
5
10
15
20
25
1-M
ar
2-M
ar
3-M
ar
4-M
ar
5-M
ar
6-M
ar
7-M
ar
8-M
ar
9-M
ar
10-M
ar
11-M
ar
12-M
ar
13-M
ar
14-M
ar
15-M
ar
16-M
ar
17-M
ar
18-M
ar
19-M
ar
20-M
ar
21-M
ar
22-M
ar
23-M
ar
24-M
ar
25-M
ar
26-M
ar
27-M
ar
28-M
ar
29-M
ar
30-M
ar
31-M
ar
WA
S o
r D
EC
AN
T (
gallo
ns)
SR
T (
da
ys
) o
r To
tal-
P (
mg
/l)
WAS DECANT Total-P SRT-7DMA
TARGET SRT = 20 DAYS
March 2013 Data
Lesson 11: Develop a “TP Compliance Strategy” to Ensure Permit Limits are Achieved
Obtain 24-hr composite effluent sample and measure Ortho-P.
Is
Ortho-
P
In Conclusion…
• EBPR in Ohio is relatively new and becoming
more common
• New requirements require effective management
of the treatment process to achieve permit limits
• Operators can use their existing knowledge
• Designers must provide flexibility
• Approach the process as a full-scale laboratory…
Allows for new ideas and for hands-on
optimization
Questions?
513-587-7078
Lessons Learned in Enhanced Biological Phosphorus Removal