Online Monitoring of Nitrate with Optical Sensors | YSI | Webinar
Transcript of Online Monitoring of Nitrate with Optical Sensors | YSI | Webinar
Online Monitoring of Nitrate with Optical Sensors for Wastewater Process Control YSI WASTEWATER WEBINAR SERIES
lamp detector
I0 I
sample
Optical Sensors Measure Light Intensity
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𝑇𝑇 =𝐼𝐼𝐼𝐼𝐼𝐼
lamp detector
I0 I
sample
Optical Sensors Measure Light Intensity
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%𝑇𝑇 =𝐼𝐼𝐼𝐼𝐼𝐼
× 100
Beer-Lambert Law Explained
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Beer-Lambert Law Explained
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Beer-Lambert Law Explained
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Beer-Lambert Law Explained
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Beer-Lambert Law Explained
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Absorption Spectrum of Wastewater
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UV Spectrum of Wastewater
UV-Visible Spectrophotometry of Water and Wastewater, O. Thomas and C. Burgess, Ed., Elsevier Publishing, 2007
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Optical Spectral Sensor Design
• 256 wavelengths measured • Xenon flash lamp / multi-diode
array detector • 1 mm or 5 mm gap • Programmed calibrations: influent,
mixed liquor, effluent • Identical measurement &
reference channel • UltraClean™ ultrasonic cleaning
technology • Sapphire measurement windows • Titanium probe body 11
Applications
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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
Process Control of Nitrification/Denitrification
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Requirements for Denitrification
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1. Nitrate – good nitrification 2. Anoxic conditions – low DO 3. Source of readily degradable carbon – wastewater or chemical
NitriTrak High DO Nitrification Tester
Met Council, Minnesota NitraVis 701 TS Built-in ultrasonic cleaning Supplemental air cleaning Installed April 2015 Goals: Aeration control Operate at lowest DO possible Keep nitrifiers alive Very low maintenance 15
Nitrate Monitoring
Higher rate Lower rate
Nitrate Monitoring
“The concept has been tried many times before, by us and others. It’s just that this time, it works with no maintenance! An adequate nitrate probe was needed.” Mike Rieth, Principal Research Engineer, Met Council
Denitrification Monitoring – WSSC Seneca
5 x NitraVis 701 TS (1 in each train) w/ supplemental air cleaning (MIQ/CHV) Goals: Effluent < 4.0 mg N/L (permit) Effluent < 3.0 mg N/L ($300k credit) Minimize Methanol Reasons for Selection Side-by-side trial Easy to set up; easy to use Low maintenance cost – no wipers
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Denitrification Monitoring – WSSC Seneca
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“Money is always an issue. I have a boss, too and I had to sell him on why we needed the probes. I have to have something that's reliable. This is the most reliable and easy to use equipment. We don’t have to chase them around all the time.” Marty Johnson, Chief Operator Seneca WWTP
NYCDEP Carbon Addition Project
63 x NitraVis 701 IQ Step-Feed Activated Sludge Goals: Target Effluent TN = 7 to 8 mg N/L Monitoring of oxic zone nitrate Feed forward control of carbon addition
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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
A Better Way to Remove Nitrogen
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1/2 mole Ammonia (NH3 / NH4
+)
1/2 mole Nitrite (NO2
-)
1/2 mole Nitrogen gas (N2)
37.5% O2
A Better Way to Remove Nitrogen
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Optical Spectral Sensors Can Resolve Nitrate and Nitrite
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wavelength [nm]
Deammonification Applications
Side-Stream Early majority stage Anaerobic digestion Nitrogen regulated areas Main-Stream Demonstration stage Alexandria Renew - Process launch 2016 Energy / Sustainability
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NiCaVis NI 701 installed in Alexandria Renew Bioreactor
Optical vs. ISE (Ion Selective Electrode)
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ISE vs. Optical Nitrate Monitoring - Cleaning
ISE Optical
ISE vs. Optical Nitrate Monitoring - Calibration
ISE – NO3 + Chloride compensation; Matrix Adjustment at commissioning/every 1 to 3 months Optical – NO3; User calibration for nitrate at commissioning* * - If needed to improve accuracy of factory calibration
ISE vs. Optical Nitrate Monitoring - Consumables
ISE Optical
ISE vs. Optical Nitrate Monitoring
Optical ISE Measuring range, mg/L as N 60 / 150 0 to 1,000 Resolution 0.01 0.1 Pressure resistance, bar 1 0.2 Power Consumption, W Up to 8 0.2 Response time (t90), min. Programmable < 3 Temperature measurement No Yes
Additional Parameters / probe COD/BOD/TOC, NO2, TSS
NH4, K, Cl
Warranty (probe), yrs 2 2 Warranty (electrodes), yrs NA 1
Optical Nitrate Sensor Types
1 mm => high concentrations, 5 mm => lower concentrations
Sensor NO3 NO2
COD/ BOD/ TOC
TSS
NitraVis √ √
NitraVis NI √ √
NiCaVis (5 mm only) √ √
NiCaVis NI √ √ √
NOx √ (NO2/3)
CarboVis √ √
Questions?
Please visit us at WEF/IWA NRR Conference in Denver, July 10 to 12. Web: www.ysi.com/wastewater Slideshare: www.slideshare.net/YSIinc YouTube: www.youtube.com/YSIinc Phone: 800-897-4151 Email: [email protected] or [email protected]
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