This document discusses measuring nitrification and denitrification rates using YSI's IQ SensorNet system at an intermittent cycle extended aeration system (ICEAS) wastewater treatment plant in Cedar Grove, WI. It provides an overview of the ICEAS technology, the YSI IQ SensorNet system and sensors, and how to calculate nitrification and denitrification rates from online sensor data. Equations and an example from the Cedar Grove plant are shown for calculating nitrification and denitrification rates based on changes in nitrate concentration, biomass levels, temperature, and reaction times under aerobic and anoxic conditions.

1. Measuring Nitrification & Denitrification
Rates with YSI's IQ SensorNet in an
Intermittent Cycle Extended
Aeration System
Visit us at WEFTEC,
booth 6239
September 2012

2. Presentation Overview
• Introduction
• ICEAS Technology
• YSI IQ SensorNet
• Nitrification & Denitrification
• Rate Calculations
• Design and Process Control
g

3. Introduction
• Cedar Grove, WI
Approximately 40 miles north
of Milwaukee.
• Activated sludge process
ICEAS.
• On-line instruments for
nitrification & denitrification
rates.
• Optimize process operations
and design with deeper
dd i ihd
understanding of nitrification
& denitrification capacity.
•3

4. Cedar Grove, WI – Commissioned 2006
Filters Digester
ICEAS
Reactors Lab
L b
Sludge Storage
Discharge

5. Cedar Grove, WI – Commissioned 2006
Influent Conditions Values
Average Dry Weather Flow 0.4 mgd (1,515 m 3/day)
Peak Wet Weather Flow 1.4 mgd (5,304 m 3/day)
BOD5 167 mg/l
TSS 297 mg/l
NH3-N 23 mg/l
P 9 mg/l
Effluent Requirements
BOD5 10 mg/l
TSS 10 mg/l
NH3-N 1 mg/l
P 1 mg/l
ICEAS® Process Design Criteria
F:M 0.04 1/day
Normal Cycle Time 4.8
4 8 hr
Number of Basins 2
Basin Length 78.83 ft. (24 m)
Basin Width 25.0 ft. (7.6 m)
Top Water Level 16.0 ft. (4.9
16 0 ft (4 9 m)
Bottom Water Level 12.0 ft. (3.7 m)

6. ICEAS Technology

7. ICEAS - Intermittent Cycle Extended
Aeration System
Pre-React Zone Main React Zone
• Usually 12-15% of Basin Volume
y • Aeration
• Acts as Biological Selector • Mixers
• Discourages Filamentous Growth • Decanter
• Allows for Continuous Flow • WAS Pump
• C ti
Continuous S Supply of C b
l f Carbon

8. ICEAS Operating Cycle
Continuous
Flow of
Screened and
Degritted
Influent
1. React 2. Settle
3. Decant Treated
Effluent
Waste Sludge

9. ICEAS Operating Cycle
Normal Cycle Operational Sequence (4.8 Hours)
0 24 48 72 96 120 144 168 228 288
AIR OFF AIR ON AIR ON AIR ON **AIR OFF AIR ON AIR ON SETTLE DECANT
Basin #1 (24 min Mix) (0-24 min) (0-24 min) (0-24 min) (24 min Mix) (0-24 min) (0-24 min) (60 min) (60 min)
144 168 228 288/0 24 48 72 96 120 144
Storm Cycle Operational Sequence (3.6 Hours)
Basin #2
AIR ON
(0-24 min)
SETTLE
(60 min)
DECANT
(60 min)
AIR OFF
(24 min Mix)
AIR ON
(0-24 min)
AIR ON
(0-24 min)
AIR ON
(0-24 min)
**AIR OFF
(24 min Mix)
AIR ON
(0-24 min)
Storm Cycle Operational Sequence (3.6 Hours)
0 18 36 54 72 90 108 126 162 216
AIR OFF AIR OFF
AIR ON AIR ON AIR ON AIR ON AIR ON SETTLE DECANT
Basin #1 (18 min (18 min
(0-18 min) (0-18 min) (0-18 min) (0-18 min) (0-18 min) (45 min) (45 min)
Mix) Mix)
108 126 162 216/ 0 18 36 54 72 90 108
AIR ON AIR OFF AIR ON AIR ON AIR ON AIR OFF AIR ON
SETTLE DECANT
Basin #2 (0-18 (18 min (0-18 (0-18 (0-18 (18 min (0-18
min)
(45 min) (45 min) Mix) min) min) min) Mix) min)

10. ICEAS Basin Cross Section
Draw Down Buffer Zone Sludge Blanket
• Difference Between • Typically 3 ft • Function of F:M
Top and Bottom • Acts as Safety Ratio
R ti
Water Level Factor • Function of
• Occupied by Influent Loading
• Limited to 1/3 of Sludge Blanket if • Target SVI = 150
TWL or Max 6 ft SVI > 150
• Function of Peak
Flow and Cycle
Times
Drawdown
Buffer Zone
Sludge Blanket

11. Probes: Midpoint of Main React Basin

12. YSI Instrumentation

13. What is inside the black box?
See what’s behind the black box with on line
what s on-line
monitoring instrumentation.

14. 4 Basic Components
Terminal / Modules Cables Sensors
Controller
4 Basic Components

15. •2020 XT Controller System
y
• Sensor network
• 1 - 20 parameters

16. Modules Power supply Wide range of power supplies:
100 – 240VAC
24VAC
24VDC
Analog outputs mA outputs
Relays
R l
Communication MODBUS
Interfaces RS232 communication to PC via sw (2020
only)
Ethernet (2020 only)
Includes barometric pressure compensation for DO for
2020
Magnetic valve Valve module for automatically controlled
air cleaning
Blue Tooth Wireless communication for the IQ
communication SensorNet system. Max. 100 meters
Inputs Accepts signal inputs from third party
analog devices

17. Cables
Sensor connection Module connection
cable cable
Cables
•One design fits all
all…
• One type of connection cable for all sensors
• One type of module connection cable

18. IQ Networking
•Distributed mounting
•Stack mounting – max. 3 modules
•Contact Plate:
•Power, communication
• Smart installation…
• Stack mounting – no cables

19. Typical Instrument Installations
DIQ/S 182 XT DIQ/S 182 XT DIQ/S 182 XT DIQ/S 182 XT
472001 472001 472001 472001
power power power power
Control
Panel
ViSolid700IQ FDO 700 IQ ViSolid700IQ FDO 700 IQ ViSolid700IQ FDO 700 IQ ViSolid700IQ FDO 700 IQ
600012 201650 600012 201650 600012 201650 600012 201650
Basin 1 Basin 2 Basin 3 Basin 4

20. IQ SensorNet Solution

21. IQ Sensors Spectrometric
• Nitrate
• COD, BOD…
y
•Conductivity Optical &
electrochemical
•D.O.
ISE
•pH / ORP Optical • Ammonium
•TSS • Nitrate
•Turbidity

22. NEW!! IFL – Interface level sensor
Ultrasonic measurement
of sludge level
• Factory calibrated
• S t immersion and
Set i i d
tank depth
• Accuracy: +/- 0 3 ft
/ 0.3

23. FDO Optical DO Sensor
• Soft green light
•Approved for • 2 year warranty
y y
Compliance
Monitoring!! • Highly accurate
• No regular sensor
maintenance required
Intelligent Sensor Cap
• Factory calibrated
• Cal data stored on
memory chip
hi
• Automatic data transfer
• N calibration required!
No lib ti i d!

24. Total Suspended Solids (TSS)
• Optical measurement
• Factory calibrated for 2 types
of sludge:
f l d
• Activated sludge 3 - 7 g/L
(scattered light)
• Primary sludge 30 - 60 g/L
(backscatter)
OR
• Correction factor: 0.5 to 2.0 –
ViSolid® 700 IQ if needed, depending on
application
• Optional calibration: 1 to 8 pt.

25. UltraClean – Ultrasonic Cleaning
TM
without cleaning system with cleaning system
A clean sensor ensures accurate measurements!
Maintenance-free sensor lowers operational costs.

26. UltraClean – Ultra Sonic Cleaning
TM
• Continuous cleaning
system without
y
mechanically moving parts
• Very smooth sensor surface
(Sapphire)
• No smearing or scratching
effect
• No regular service, no wear
and tear, no replacement
parts needed

27. VARiON® Plus 700 IQ, AmmoLyt ® Plus 700 IQ,
NitraLyt® Plus 700 IQ – ISE Measurement
•Measurement principle:
• Measuring, reference and
compensation electrode.
• Nit t requires Chl id
Nitrate i Chloride
NitraLyt®Plus compensation for highest
accuracy.
•AAmmonium requires
i i
Potassium compensation for
highest accuracy
®Plus
l
AmmoLyt®Plus VARiON

28. Electrode Replacement
• Individual electrode
replacement lowers lifetime
p
costs
• Electrodes warranted for 12
months

29. Nitrification & Denitrification

30. Ammonification / Nitrification
• Organic-nitrogen  ammonia-nitrogen
• Ammonia-nitrogen  nitrate-nitrogen
• Aerobic conditions
A bi diti
• Temperature, SRT, pH, DO, and alkalinity
• Autotrophic bacteria (CO2)
Org-N Ammonification
Org-N → NH4-N
TKN
Nitrification NO3-N
NH4-N NH4-N →NO2-N→NO3-N
Cell
Growth

31. Denitrification
• Nitrate-nitrogen  nitrogen gas
• Bacteria use chemically bound O2 in lieu of dissolved
oxygen
• Anoxic environment
• Heterotrophic bacteria (organic matter)
• Temperature dependent
Nitrogen
• Rate impacted by carbon source Gas
Org-N Ammonification
Org-N → NH4-N
Denitrification
TKN
NO3-N →N2
Nitrification NO3-N
NH4-N NH4-N →NO2-N→NO3-N
Cell Cell
Growth Growth

32. Rate Calculations

33. Data for Calculating Rates
Defining nitrification or denitrification rates:
• Time duration of aerobic or anoxic conditions
• Change in Nitrate concentration (NO3)
• Mass of mixed liquor volatile suspended solids (MLVSS)
• Reactor temperature
Also consider:
• Oxidation Reduction Potential (ORP)
• Di
Dissolved O
l d Oxygen (DO)

34. REACT Cedar Grove
M AIR S D 8
AIR OFF
7
Nitrification
6
5
mg/l
4
3
2
1
0
8:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00 0:00 2:00 4:00 6:00 8:00
Time
DO NH4 NO3

35. y
Nitrification PRZ
MLSS 1,045 mg/L
SS
MLVSS 732 mg/L
3 g/
water level 13.2 ft
volume 24,684 gal
MLVSS for PRZ MLVSS 151 lb
MRZ
MLSS 2,090 mg/L
MLVSS 1,463 mg/L
water level 13.2 ft
volume 165,383 gal
MLVSS for MRZ MLVSS 2,019
2 019 lb
Nitrate
temperature 14.4 °C
water level 14.50 ft
initial NO3-N 1.28 mg/L
final NO3-N 6.62 mg/L
∆ NO3-N 5.34 mg/L
initial time 8:28 AM
∆NO3 = NH3-N nitrified final time 10:57 AM
aeration ti
ti time 2.48 hours
NH3-N nitrified 9.69 lb
Nitrification Rate
Nitrification rates @T °C and @20 °C KnT 0.00180 lb NH3-N/lb MLVSS-hr @ T°C
θ 1.080
1 080 unitless
Kn20 0.00277 lb NH3-N/lb MLVSS-hr @ 20°C

36. REACT Cedar Grove
M AIR S D 8
AIR OFF
7
Nitrification
Denitrification
6
5
mg/l
4
3
2
1
0
8:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00 0:00 2:00 4:00 6:00 8:00
Time
DO NH4 NO3

37. Denitrification Cycle Morning Settle
PRZ
MLSS 1,246 mg/L
MLVSS 1,165 mg/L
water level 12.91 ft
volume 24,142 gal
MLVSS for PRZ MLVSS 235 lb
MRZ
MLSS 1,806 mg/L
MLVSS 1,589 mg/L
water level 12.91 ft
volume 161,749 gal
MLVSS for MRZ MLVSS 2,145 lb
Nitrate
temperature 17.7 °C
initial water level 13.82 ft
final water level 14.16 ft
initial NO3-N 9.14 mg/L
final NO3-N 6.90 mg/L
∆ NO3-N -2.24 mg/L
initial time 12:05 PM
∆NO
-∆NO3 = NO3 Denitrified final time 12:49 PM
anoxic time 0.73 hours
NO3-N denitrified 3.44 lb
Denitrification Rate
Denitrification rates
@T °C and @20 °C
KdnT 0.00197 lb NO3-N/lb MLVSS-hr @ T°C
@ @ θ 1.080
1 080 unitless
Kdn20 0.00235 lb NO3-N/lb MLVSS-hr @ 20°C

38. Cedar Grove
10 3000
9
NITE
REACT 2500
8
DENITE
7
2000
NH4, NO3, DO (mg/l)
6
5 1500
DENITE
4
1000
3
2
500
1
0 0
9/30/2011 9/30/2011 9/30/2011 9/30/2011 9/30/2011 9/30/2011 9/30/2011 9/30/2011 9/30/2011 9/30/2011 10/1/2011
0:00 2:24 4:48 7:12 9:36 12:00 14:24 16:48 19:12 21:36 0:00
Time
SETTLE &
DECANT NH4-N NO3-N DO MLSS

39. ICEAS Operating Cycle
Normal Cycle Operational Sequence (4.8 Hours)
0 24 48 72 96 120 144 168 228 288
AIR OFF AIR ON AIR ON AIR ON **AIR OFF AIR ON AIR ON SETTLE DECANT
Basin #1 (24 min Mix) (0-24 min) (0-24 min) (0-24 min) (24 min Mix) (0-24 min) (0-24 min) (60 min) (60 min)
144 168 228 288/0 24 48 72 96 120 144
AIR ON SETTLE DECANT AIR OFF AIR ON AIR ON AIR ON **AIR OFF AIR ON
Basin #2 (0-24 min) (24 min Mix) (0-24 min) (0-24 min) (0-24 min) (24 min Mix) (0-24 min)
(60 min) (60 min)
Storm Cycle Operational Sequence (3 6 Hours)
(3.6
0 18 36 54 72 90 108 126 162 216
AIR OFF AIR OFF
AIR ON AIR ON AIR ON AIR ON AIR ON SETTLE DECANT
Basin #1 (18 min (18 min
(0-18 min) (0-18 min) (0-18 min) (0-18 min) (0-18 min) (45 min) (45 min)
Mix) Mix)
108 126 162 216/ 0 18 36 54 72 90 108
AIR ON AIR OFF AIR ON AIR ON AIR ON AIR OFF AIR ON
SETTLE DECANT
Basin #2 (0-18 (18 min (0-18 (0-18 (0-18 (18 min (0-18
min)
(
(45 min)
) (
(45 min)
) Mix) min) min) min) Mix) min)

40. Denitrification – First Period Vs. Fifth Period
Cycle First Period Mix Cycle Fifth Period Mix
PRZ PRZ
MLSS 1,161 mg/L MLSS 1,161 mg/L
MLVSS 1,085 mg/L MLVSS 1,085 mg/L
water level 13.07 ft water level 13.07 ft
volume 24,434 gal volume 24,434 gal
MLVSS 221 lb MLVSS 221 lb
MRZ MRZ
MLSS 1,682 mg/L MLSS 1,682 mg/L
MLVSS 1,480 mg/L MLVSS 1,480 mg/L
water level 13.07 ft water level 13.07 ft
volume 163,708 gal volume 163,708 gal
MLVSS 2,022
2 022 lb MLVSS 2,022
2 022 lb
Nitrate Nitrate
temperature 18.5 °C temperature 18.5 °C
initial water level 12.14 ft initial water level 13.10 ft
final water level 12.31 ft final water level 13.39 ft
initial NO3-N 4.28 mg/L initial NO3-N 8.05 mg/L
final NO3-N 3.69 mg/L final NO3-N 6.56 mg/L
? NO 3-N -0.59341 mg/L ? NO 3-N -1.48761 mg/L
initial time 7:59 AM initial time 9:24 AM
final time 8:12 AM final time 9:48 AM
aeration time
anoxic time 0.22
0 22 hours aerationtime
anoxic time 0.40
0 40 hours
NO3-N denitrified 0.79 lb NO3-N denitrified 2.12 lb
Denitrification Rate Denitrification Rate
KdnT 0.00162 lb NO3-N/lb MLVSS-hr @ T°C KdnT 0.00236 lb NO3-N/lb MLVSS-hr @ T°C
θ 1.080 unitless θ 1.080 unitless
Kdn20 0.00182 lb NO3-N/lb MLVSS-hr @ 20°C Kdn20 0.00265 lb NO3-N/lb MLVSS-hr @ 20°C

41. Design and Process Control

42. How Do We Use this Data?
Design Stage:
• Compare measured rates at different facilities, perhaps to
identify the impact of influent BOD/TKN ratios
• Determine cycle structure (4, 5, 6 cycles/day)
• C l l
Calculate anoxic & aerobic time within cycle
i bi i i hi l
• Reconcile nitrifier specific growth rate (μmax) with
nitrification rate for SRT calculation
• Better understand denitrification capacity during settle

43. How Do We Use this Data?
Operations:
• Provides a “health check” of system – decreased rates
health check
could confirm inhibition
• Predicts actual MLVSS required for nitrification &
denitrification
• Identifies real-time nitrification and denitrification capacity
• Compare actual SRT with design SRT
p g
• Determine aerobic (air-on) and anoxic time (air-off) to
meet total N requirement
• O li effluent ammonia and nitrate readings when
Online ffl t i d it t di h
system is in settle/decant phase

44. Questions…

45. Thank you for your attention!
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