The document discusses advancements in online process monitoring and automation for water resource recovery facilities, focusing on new technologies such as solid-state in-situ sensors and multiparameter controllers. It highlights the importance of accurate measurements for dissolved oxygen, nitrogen, and total suspended solids while detailing various control strategies and sensor types for effective water treatment. Additionally, it mentions specific models and features of sensors designed to improve nutrient removal and recovery processes.

1. Process Monitoring and Automation
of Water Resource Recovery
Facilities (WRRF)

2. What’s Inside?
• Online process monitoring instrumentation –
what’s new?
• Dissolved Oxygen measurement (optical)
• DO aeration control
• Nitrogen measurement (ISE)
• Ammonium based aeration control
• TSS
• SRT (Solids Retention Time) control
• Nitrogen, COD, phosphate

3. Online Process Monitoring Instrumentation
• Solid-state in-situ sensors
• Multiparameter universal controllers
• Digital communications
• Measurement
• New parameters – NH4, NOx
• New methods – DO, TSS
• Better performance
What’s new

4. Solid-State In-Situ Sensors
Signal processing in sensor
• Auto-recognition (plug & play)
• Calibration
• Multiple measurements
• Self-diagnostics

5. IQSN Sensors

6. Multiparameter, Universal Controllers
Brain of the system
• Up to 20 channels
• Measurement display
• Internal communications
• Operating functions

7. IQ SensorNet Controller Digital
Expandable Multi-location System
Model 2020XT: 1 – 20 parameters

8. Customized solutions,
happy customers…
Units are separated and encased
in standardized modules,
adaptable to local conditions
Power supply
Analog outputs / inputs
Interfaces
System extension
Controller in a module
Modules

9. Digital Communications
Enhanced signal stability
• Simultaneous and 2-way
communication
• Convenient placement of
components
• Large distances
• Less cabling
• RS-485, Modbus, profibus,
Ethernet IP, Modbus TCP/IP

10. Dissolved Oxygen
(Optical)

11. Optical insulation
Filter
Detector
Optical DO Sensor - FDO
Gas selective membrane
with fluorescence dye

12. Step 1: Excitation flash
Step 2: Fluorescence flash:
Starting time and intensity
depend on O2 concentration
Oxygen Measurement

13. Oxygen Measurement
Time or intensity • Time
• Highly
accurate
• No
interferences
from ambient
light /
bleaching
• Check: some
signal must
be detected

14. Effect of DO Concentration on Biological
Treatment
Basis for maintaining DO at or below 2 mg/L setpoint
D.O.  Reaction 
0.75
D.O.  : Reaction 
D.O. ~ 2 mg/l  sufficient for
nitrification
COD removal
Nitrification
0.5 1.0 2.01.5 2.5 3.0 O2 (mg/l)
1/2 vmax
vmax
Reactionrate
0.3

15. Automated DO Control Alternatives
• On-off
• Mixing required
• Never at setpoint
• Direct control of airflow
• Difficult control problem - DO vs. airflow non-linear

16. Cascade Control
Most effective / most complicated
PI

17. FDO 700 IQ

18. Optical DO Sensor

19. Intelligent Sensor Cap (Replaceable)
• Data stored on memory chip
• Automatic transfer of
calibration constants
Individual factory calibration

20. Interferences
Bubbles & coatings cause
overestimate and erratic
measurements

21. Interferences

22. Nitrogen Removal – The
Traditional Way

23. 1 mole Ammonia
(NH3 / NH4
+)
1 mole Nitrite
(NO2
-)
1 mole Nitrate
(NO3
-)
1 mole Nitrite
(NO2
-)
1/2 mole Nitrogen gas
(N2)
75% O2
25% O2
40% Carbon
60% Carbon
Nitrification /
Denitrification
Aerobic Anoxic

24. Ion Selective Measurement System

25. Nitrification - Denitrification
Pre denitrification (MLE) • Anoxic zones –
denitrification
• Oxic zones (DO
control) – nitrification
• Mixers to uncouple
aeration/mixing
(anoxic)
• Recirculation – IMLR
• Readily degradable C
– ww or methanol ($$)
• Sensors & control
system
Ingildsen, P, Wendelboe, H., “Improved nutrient removal results using in situ
continuous on-line sensors with reduced response time”, WEFTEC 2003

26. Ammonium-Based Aeration Control
Feedback control
• Direct control on ammonium
• DO not controlled at all
• Direct control w/ DO limit
(ceiling)
• DO changes faster –
control authority?
• Cascade control
• Ammonium controller
calculates DO setpoint

27. VARiON Plus 700 IQ, AmmoLyt Plus 700 IQ,
NitraLyt Plus 700 IQ - Nitrogen Measurement

28. VARiON® Plus 700 IQ
AmmoLyt® Plus 700 IQ
NitraLyt® Plus 700 IQ
ISE Sensors for Ammonium (NH4), Nitrate
(NO3)

29. ISE Sensor Design
Four individual electrodes
• NH4, NO3, K, Cl
• 1-yr. warranty
• Automatically recognized in
system

30. AmmoLyt Plus 700 IQ NitraLyt Plus 700 IQ
VARiON Plus 700 IQ
3 slots 3 slots
Sensor Types

31. Total Suspended Solids

32. Optical Measurement of Solids
Particles absorb, reflect, scatter light

33. Intensity
Turbidity / Suspended Solids
90° (DIN, ISO,
US EPA) < 90°
180° (or back
scatter)
Effect of Measuring Angle on Measuring
Range

34. 0.0
4.0
8.0
12.0
16.0
5 10 15 20 25
NitrificationSRT,dSRT (Solids Retention Time) Required for
Nitrification
Design SRT; SF=1.5
Operating Range
Change SRT by changing
wasting rate
Min. SRT
Temperature, °C

35. Approaches to SRT Control
Qe, Xe
V, MLSS
Qr, Xr Qw, Xr
Qi, Xi
SRT setpoint
Qw

36. Sensor Maintenance
Ultrasonic cleaning with
UltraClean technology &
sapphire windows
• No wipers
• No moving parts

37. without cleaning system (30 days) with cleaning system (30 days)
UltraClean Ultrasonic Cleaning

38. Nitritation - Anammox

39. 1 mole Ammonia
(NH3 / NH4
+)
1 mole Nitrite
(NO2
-)
1 mole Nitrate
(NO3
-)
1 mole Nitrite
(NO2
-)
1/2 mole Nitrogen gas
(N2)
75% O2
25% O2
40% Carbon
60% Carbon
Aerobic Anoxic
Anaerobic

40. 1 mole Ammonia
(NH3 / NH4
+)
1 mole Nitrite
(NO2
-)
1 mole Nitrate
(NO3
-)
1/2 mole Nitrogen gas
(N2)
Aerobic Anoxic
Deammonification
Anaerobic
37.5% O2

41. 2013 WEF/IWA Nutrient Removal &
Recovery Conference

42. UV Sensor – Principle of Measurement
• Absorbance depends on
• Concentration (what you are measuring)
• Optical path length (distance from lamp to detector)
• Transmission characteristics of sample (everything in
the water that absorbs or reflects light)
lamp detector
I0 I
Light gets absorbed
/ weakened by
sample
sample

43. What Different Wavelengths Tell You About
What is in the Sample
Measurement & compensation

44. Difference Between UV and UV-VIS Sensors
Measurement of NO2 and NO3
• 256 wavelengths measured
• 200 – 390 nm
• 0.74 nm resolution
wavelength [nm]

45. COD, TOC, BOD,
NO3-N, TSS mg/lmathematics
Calculation
• Measurement procedure
1. Record spectra
2. Calculate concentrations from model
Models stored in instrument

46. Deammonification
• Sidestream treatment (DEMON®
, MBBR)
• Mainstream treatment
Applications
46

47. CarboVis, NitraVis, NiCaVis, NiCaVis NI
UV-VIS and UV Spectral Measurement

48. 200 nm 720 nm
Immersible Spectrophotometer
256 wavelengths

49. Low Maintenance
Durable / low ownership cost
• Integrated UltraClean
ultrasonic cleaning
• Very hard, smooth sapphire
window
• No wipers
• Titanium / PEEK

50. • NitraVis: NOx, (TSS)
• CarboVis: SAC, CODtotal, CODsoluble, BOD, DOC, TOC,
(TSS)
• NiCaVis NI: NO3, NO2, SAC, CODtotal, CODsoluble, BOD,
DOC, TOC
• 200 nm to 390 nm (UV only)
• Measuring gap
• 1 mm (high concentrations)
• 5 mm (low concentrations)
Sensor Types
Up to 5 parameters on one sensor

51. Phosphate

52. Chemical P Removal
• Effluent monitoring
• Feedback control
• Pre-precipitation
• Post-precipitation
• Feed forward control
• Feedback feed forward
P 700 IQ P 700 IQ P 700 IQ

53. Features
• Low reagent consumption
• Optional outdoor climate package
• Automatic calibration
• Integrated permeate pump
• Filter module

54. Application Example Chemical Dosing
Flocculating
agent
Phosphate
[mg/l]
time
Use of P700 IQ for regulation of
flocculating agent dosage

55. Resources
YSI.com/IQ
bit.ly/IQwin (win an IQ instrument)
bit.ly/IQanimation (IQ overview video)
bit.ly/IQfeatures (IQ features video)
bit.ly/IQcolorado (IQ installed in WWTP in Colorado)
blog.ysi.com/IQ-SensorNet (related blog posts about IQ)

57. Contact Us
+1 (937) 767-7241
(800) 765-4974
info@ysi.com
YSI.com
@YSIinc