online wastewater process ise sensors | how to get the best data | ysi iq sensornet
TRANSCRIPT
How to Get the Best Data - Online Wastewater Process Ammonium & Nitrate Sensors YSI WASTEWATER WEBINAR SERIES
Today’s Topics
Process Monitoring of Ammonium & Nitrate • Sensor Design & Selection • Applications • Probe Operation & Care • Calibration
- Matrix Adjustment • YSI IQ SensorNet Features & Specs Ion Selective Electrode (ISE) Technology 2
Process ISE Design
Very similar in design to a pH/ORP sensor. • Electrochemical (potentiometric) • 2 or more replaceable electrodes • No reagents • Cylindrical probe Measures charged substances.
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ISE Selection
Get the right probe for your application. • Ammonium (A) ; Nitrate (N) ; A + N • Compensation
- K for A - Cl for N - pH for A
• Individual electrodes vs. cartridge • Acquisition cost $4,500 to $10,000 • Ownership cost $1,000 to $2,000 / yr. Simpler, less expensive alternative to cabinet wet chemistry analyzers.
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Applications
A & N ISEs are useful for control of aeration & wasting, recirculation & chemical (carbon) dosing. • Nitrification • Denitrification • Ammonia Based Aeration Control Many other applications possible.
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A & N ISE Operation & Care
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Operation
Ensure reliable operation by practicing the following simple procedures:
• Choose a representative & accessible measurement location - Observe max immersion
• Clean when necessary - Utilize supplemental air cleaning if needed
• Verify measurement regularly - Calibrate as needed (matrix adjustment /
correction) • Replace electrodes when needed
More details to follow.
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Cleaning
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Slime/biomass accumulation affects measurement reliability. • Use process water
- Never use DI water (shocks the measurement cell / long recovery time) - Never use soaps/detergents (damages the membrane / shortens life)
• Use soft bristle brush (like a toothbrush) Supplemental automatic air cleaning may extend cleaning intervals.
Verification
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Compare laboratory reference measurements on grab samples with monitoring system display. Sensor value – reference = Error Acceptable error is determined by customer. Usually +/- 10 to 20%.
Error
Sampling / Sample Prep
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• Determine best time to sample - Process is stable - Concentration > 0.1 mg/L
• Sample near sensor - Horizontal and vertical position
• Filter immediately into clean sample vial
Calibration
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59.2 mV
Ideal slope (S) is 59.2 mV / decade (logarithmic scale) Offset (U0
ion) is influenced by unique sample properties (matrix)
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Calibration Methods
Cal. Method Offset (Uo
ion) Slope
(S) Location Standards Reference
(Lab) Method
Single-point Lab Middle of range (1)
2-point Lab Ends of range (2)
Standard Addition Bucket High Conc.
(1)
Sample (Matrix Adjustment)
Process None required
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Calibration Methods
Cal. Method Offset (Uo
ion) Slope
(S) Location Standards Reference
(Lab) Method
Single-point Lab Middle of range (1)
2-point Lab Ends of range (2)
Standard Addition Bucket High Conc.
(1)
Sample (Matrix Adjustment)
Process None required
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Factory slope is stable (IQSN) Sensor stays in the process No preparation/purchase of standards required
Matrix Adjustment
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Materials Recommended
• Long-handle sample dipper • 10 to 30 mL syringe w/ Luer Lock tip • 0.45 μm syringe filter(s) w/ Luer Lock fitting • Clean sample vials • Pipettes & tips • Colorimeter with test kits • Test kits for ammonium, nitrate, potassium, and chloride*
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IQSN Procedure
1. Clean electrodes 2. Record sample conditions • mV signal
3. Take sample 4. Measure in lab and evaluate • Ammonia, Nitrate, Potassium, Chloride * • Duplicate or triplicate measurement recommended
5. Update sensor value(s) and check • What mV value is expected? What was the actual value?
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Demonstration
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Closing Thoughts
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Summary
ISEs for Process Monitoring of Ammonium & Nitrate • Potentiometry – similar to pH/ORP • Applications: Nitrification, Denitrification, & ABAC
• A, N, A+N, compensation • Measurement location, cleaning and verification techniques
• Matrix adjustment preferred calibration method
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Features of YSI IQSN ISEs
Durable stainless steel probe SS mesh protects membrane Longest electrode lifetime in the industry 18 to 24 mths. 1 yr. warranty Individually replaceable electrodes simple replacement Digital technology – autorecognition Best performance Competitive pricing 20
IQ SensorNet Trade-In Program
20% off the YSI IQ SensorNet 2020 XT system 10% off the YSI IQ SensorNet 182 system Offer good on competitors’ systems Expires December 31, 2016 http://bit.ly/IQtradein
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Questions?
Web - www.ysi.com/wastewater Slideshare – www.slideshare.net/YSIinc YouTube – www.youtube.com/YSIinc Phone: 1-800-897-4151 Email: [email protected] or [email protected]
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