instrumentation for process control 09
DESCRIPTION
TRANSCRIPT
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InstrumentationInstrumentationforfor
Process ControlProcess Control
Gregg CunninghamGregg CunninghamConsultant/TrainerConsultant/Trainer
Three Gez ConsultingThree Gez ConsultingEmail:[email protected]:[email protected]
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OutlineOutline
• Optimizing Process PerformanceOptimizing Process Performance• Lab InstrumentsLab Instruments
• On-line InstrumentsOn-line Instruments
• Know your processKnow your process
• Data analysisData analysis
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OutlineOutline• Specific Cost/Energy Savings PointsSpecific Cost/Energy Savings Points
• Source waterSource water
• Flocculation AidsFlocculation Aids
• Filter PerformanceFilter Performance• Filter EffluentFilter Effluent• Filter to WasteFilter to Waste• BackwashBackwash
• Disinfection controlDisinfection control
• DistributionDistribution
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OutlineOutline
• Process Instruments Hands-on/DemoProcess Instruments Hands-on/Demo• Effects of changing water chemistry on Effects of changing water chemistry on
process instrumentsprocess instruments
• Summary and ConclusionsSummary and Conclusions
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Optimizing Process Optimizing Process PerformancePerformance
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Lab InstrumentsLab Instruments
• Generally used for compliance purposesGenerally used for compliance purposes
• Lab must have a QC/QA program in Lab must have a QC/QA program in placeplace
• Lab instruments must be capable of Lab instruments must be capable of running the same methods as the on-line running the same methods as the on-line instrumentsinstruments
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Lab InstrumentsLab Instruments
• Grab Sample PointsGrab Sample Points• MUST be representative of the processMUST be representative of the process
• Easily accessibleEasily accessible
• Consistently use the same pointConsistently use the same point
• Correctly locateCorrectly locate• Sample tapSample tap• ““Dip” sample pointDip” sample point
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Lab InstrumentsLab Instruments
• Grab SamplesGrab Samples• Flush sample container with sample at least Flush sample container with sample at least
three times (unless a preservative is added)three times (unless a preservative is added)
• If it is a sample tapIf it is a sample tap• Let it run to flush out the lineLet it run to flush out the line
• If a basinIf a basin• Do not scrape side wallDo not scrape side wall• Do not get surface scumDo not get surface scum• Try to get towards the centerTry to get towards the center
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The analysis is only as good as The analysis is only as good as the sample!the sample!
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Recommended Sample TapsRecommended Sample Taps
XX PoorPoor, may , may draw draw sedimentsediment
XXPoorPoor, avoid ells, , avoid ells, valves, T’s and other valves, T’s and other areas of turbulenceareas of turbulence
BetterBetter
PoorPoor, , may draw may draw airair
BestBest
XXX
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Lab InstrumentsLab Instruments
• Calibration and VerificationCalibration and Verification• Follow manufacturers recommendationsFollow manufacturers recommendations
• Follow State or USEPA regulationsFollow State or USEPA regulations
• Always use fresh standards and verify with Always use fresh standards and verify with third party standardsthird party standards
• Have instrument calibrated by qualified Have instrument calibrated by qualified service technician at least once a yearservice technician at least once a year
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Lab InstrumentsLab Instruments
• Use the right instrumentUse the right instrument• Do not use a spectrophotometer to do Do not use a spectrophotometer to do
turbidityturbidity• Spec will not do 90Spec will not do 90° detection or forward ° detection or forward
scatterscatter
• Instrument must have the correct resolutionInstrument must have the correct resolution• PCII for Cl/pH only reads to a tenthPCII for Cl/pH only reads to a tenth• Pkt Turb could only read to a tenthPkt Turb could only read to a tenth
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Lab InstrumentsLab Instruments
• Use the correct procedureUse the correct procedure• Monochloramine vs total chlorineMonochloramine vs total chlorine
• Correct speciesCorrect species• As P or as POAs P or as PO44??
• DigestionDigestion
• DistillationDistillation
• Correct rangeCorrect range
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Lab InstrumentsLab Instruments
• QC/QAQC/QA• Control chartsControl charts
• 10% of all tests run should be QC/QA10% of all tests run should be QC/QA• StandardsStandards• SpikesSpikes• UnknownsUnknowns
• MDL’s must be established for each lab MDL’s must be established for each lab tech for each parameter reportedtech for each parameter reported
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LABORATORY VS ON-LINELABORATORY VS ON-LINE
• Monitoring may be carried out by Monitoring may be carried out by collecting grab or composite samples collecting grab or composite samples and then analyzing them in the and then analyzing them in the laboratory.laboratory.
Requires large amounts of time and Requires large amounts of time and laborlabor
Possibility of inconsistent results due to Possibility of inconsistent results due to variations in technique at time of variations in technique at time of sampling and/or analysissampling and/or analysis
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LABORATORY VS ON-LINELABORATORY VS ON-LINE
Grab or composite sampling may Grab or composite sampling may not detect a problem (such as not detect a problem (such as underfeed or overfeed of treatment underfeed or overfeed of treatment chemicals) soon enough to prevent chemicals) soon enough to prevent process problems or failure.process problems or failure.
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LABORATORY VS ON-LINELABORATORY VS ON-LINE
• Laboratory (grab) samples can be Laboratory (grab) samples can be used to supplement the on-line used to supplement the on-line instrumentationinstrumentation Parameters not needing constant Parameters not needing constant
measurement or controlmeasurement or control Problem solvingProblem solving Checking calibration of on-line instrumentsChecking calibration of on-line instruments
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LABORATORY VS ON-LINELABORATORY VS ON-LINE
• What’s better: Lab or Process?What’s better: Lab or Process?• Most lab errors can be tied to the “human Most lab errors can be tied to the “human
factor” or “pilot error” factor” or “pilot error”
• Process instruments are generally self-Process instruments are generally self-diagnosing and will tell you if there is a diagnosing and will tell you if there is a problemproblem
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LABORATORY VS ON-LINELABORATORY VS ON-LINE
• Automated Analysis (On-line) is the Automated Analysis (On-line) is the key to solving critical water problems key to solving critical water problems and reducing labor requirements.and reducing labor requirements.
• Fast detection and correction of Fast detection and correction of abnormalities in each unit process abnormalities in each unit process can cut treatment costs and keep a can cut treatment costs and keep a plant process in control.plant process in control.
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On-Line Process InstrumentsOn-Line Process Instruments
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Process InstrumentsProcess Instruments
Automate analytical tests for on-line, Automate analytical tests for on-line, continuous monitoring and controlcontinuous monitoring and control
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ADVANTAGES:ADVANTAGES:
• Detect process problemsDetect process problems
• Save operator timeSave operator time
• Reduce operator errorReduce operator error
• May save reagent costs vs lab May save reagent costs vs lab teststests
• May be used for feed controlMay be used for feed control
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CONSIDERATIONS IN CONSIDERATIONS IN SELECTING AN INSTRUMENTSELECTING AN INSTRUMENT
• Does it meet your needsDoes it meet your needs• Example: particle counter vs laser turb vs Example: particle counter vs laser turb vs
LR turbLR turb
• Does it measure the parameter neededDoes it measure the parameter needed• Monochloramine vs total chlorineMonochloramine vs total chlorine
• Is it in the proper rangeIs it in the proper range• HR turb not accurate at low rangeHR turb not accurate at low range
• High or low end 5% of range is ???High or low end 5% of range is ???
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CONSIDERATIONS IN CONSIDERATIONS IN SELECTING AN INSTRUMENTSELECTING AN INSTRUMENT
• Is it reliableIs it reliable
• Is it easy to operateIs it easy to operate• User friendly interfaceUser friendly interface
• Is it low maintenanceIs it low maintenance• APA6000APA6000
• What are the featuresWhat are the features• Outputs (compatible with current and future Outputs (compatible with current and future
needs)needs)
• Software/hardware upgradeable (field or factory)Software/hardware upgradeable (field or factory)
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CONSIDERATIONS IN CONSIDERATIONS IN SELECTING AN INSTRUMENTSELECTING AN INSTRUMENT
• What is the What is the costcost, not just the , not just the priceprice• Get the sales rep to provide the Cost Get the sales rep to provide the Cost
of Ownershipof Ownership• Initial costInitial cost
• Maintenance cost (including labor)Maintenance cost (including labor)
• Reagent costReagent cost
• Replacement parts costReplacement parts cost
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Cost of OwnershipCost of OwnershipWDMP Dascore Panel Builder
Grab Sampling
$12,800.00 $9,750.00 $15,000.00 $2,500.00
$34.00 $0.00 $71.00 $5.00
$34.00 $0.00 $71.00 $5.00
Estimated Mtnc. labor rate per hour $17.00 $17.00 $17.00 $17.00 $17.00
Labor Time in hours per month 0.25 0.25 1.00 0.75
Estimated Laboratory labor rate per hour $20.00 0 0 0 20Labor Time per month in hours - (assumes 1hr Lab Staff time per sampling event for current
30 0 0 0 30
$38.25 $4.25 $88.00 $617.75
$218.00 $600.00 $0.00 $0.00
30 60 0 0
$235.00 $1,234.00 $0.00 $0.00
Number of Sample Events per Month per Site (Sampling frequency every X min.)
1 43200 43200 43200 30
$13,494.00 $11,035.00 $16,056.00 $9,913.00
Amortized Cost Per Site Per Year Over X Years (Amortization Period)
5 $3,254.00 $3,235.00 $4,056.00 $7,913.00
Total Network Cost (# Units Required) 1 $13,494.00 $11,035.00 $16,056.00 $9,913.00
$3,254.00 $3,235.00 $4,056.00 $7,913.00
$0.01 $0.01 $0.01 $21.981
$0.37 $0.37 $0.46 N/A$8.92 $8.86 $11.11 $21.68
Hourly cost for 24/7 monitoring including all labor, parts and instrument cost
Cost of Reagents/month
Total monthly cost of reagents
Cost monthly lab & mtnc. Including reagents and labor
Average Daily Cost
WDMP Water Monitoring Network
Annual cost to change sensor module once per 6 months - Including parts and labor
Labor Time in minutes - Sensor Module (assume 2 people - total minutes)
Incremental Cost per Sampling event (per site)
Total Network Annualized Amortized Cost
Enter appropriate variables in yellow highlighted cells. All other cells calculate automatically.
Cost of Instrument + Installation
Price Sensor Module, changed every six months
Cash Outlay per site (per unit) for Year 1
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CONSIDERATIONS IN CONSIDERATIONS IN SELECTING AN INSTRUMENTSELECTING AN INSTRUMENT
• ServiceService• Who can work on the instrument? Who can work on the instrument?
• While under warranteeWhile under warrantee
• After warranteeAfter warrantee
• What is their response time?What is their response time?
• Is there a service plan available?Is there a service plan available?• Can help to control service costsCan help to control service costs
• Best for multiple instrumentsBest for multiple instruments
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Installation of On-line Installation of On-line InstrumentsInstruments
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Instrument Installation: Key to Proper Instrument Installation: Key to Proper PerformancePerformance
• Select proper location Select proper location • As near to the sample point as practicalAs near to the sample point as practical
• Reduces sampling errorsReduces sampling errors• Reduces lag timeReduces lag time
• Avoid dead ends, valves, bendsAvoid dead ends, valves, bends• Minimize errors due to air bubbles, Minimize errors due to air bubbles,
turbulence, etc.turbulence, etc.• Level, insulated from vibrationLevel, insulated from vibration• Good conditions of heat and humidity - Good conditions of heat and humidity -
avoid direct sunlight.avoid direct sunlight.• Avoid sample pumpsAvoid sample pumps
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Turbidimeter PanelTurbidimeter Panel
• Measurement accuracy and response time are Measurement accuracy and response time are sacrificed for convenience and appearance.sacrificed for convenience and appearance.
• Good for public relations, poor for analysisGood for public relations, poor for analysis
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Turbidimeters Mounted at Turbidimeters Mounted at Sample PointSample Point
• Instruments Instruments should be installed should be installed as close as as close as possible to the possible to the sample point for sample point for greatest accuracy greatest accuracy and best response and best response time.time.
Power isolation switch
Flow Control
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Poor Installation Can Lead To Poor Installation Can Lead To Erroneous ConclusionsErroneous Conclusions
• Particle counts Particle counts real timereal time
• Turbidity Turbidity measurements measurements delayed in time delayed in time approximately approximately 15 minutes due 15 minutes due to installation to installation in a panel in a panel arrangementarrangement
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1
1 0
1 0 0
1 0 0 0
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F i l t e r R u n - H o u r s
Partic
les Pe
r Millili
ter
0
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0 . 1
0 . 1 2
0 . 1 4
Turbi
dity (
ntu)
T u r b i d i t y
P a r t i c l e C o u n t s
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Example of Sampling ErrorExample of Sampling ErrorDo The Math!Do The Math!
• PoorPoor
• Sample pipe 100’ Sample pipe 100’ (3048 cm)(3048 cm)
• ¾” (1.9 cm) pipe¾” (1.9 cm) pipe
• Flow 200 mL/minFlow 200 mL/min
• OptimalOptimal
• Sample line 5’ Sample line 5’ (152 cm)(152 cm)
• ¼” (0.635 cm) line¼” (0.635 cm) line• Flow 200 mL/minFlow 200 mL/min
VSVS
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Poor SamplingPoor Sampling
Measurement Units (select
from list)Enter Diameter (d) in
Enter pipe or tubing length (l) in Volume in Volume in
Metric Centimeters Centimeters ccs or mL Liters1.9 3048 8641.70103 8.642
Enter flow rate (Q) in ml/min
200 2592.510 43.209
V = π x (d/2)2 x lTubing/Pipe Volume & Sample Delay
Delay time in seconds
Delay time in minutes
d
l
Q
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Optimal SamplingOptimal Sampling
Measurement Units (select
from list)Enter Diameter (d) in
Enter pipe or tubing length (l) in Volume in Volume in
Metric Centimeters Centimeters ccs or mL Liters0.635 152 48.13579083 0.048
Enter flow rate (Q) in ml/min
200 14.441 0.241
V = π x (d/2)2 x lTubing/Pipe Volume & Sample Delay
Delay time in seconds
Delay time in minutes
d
l
Q
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Increase flow but stillIncrease flow but stillPoor Sampling!Poor Sampling!
Measurement Units (select
from list)Enter Diameter (d) in
Enter pipe or tubing length (l) in Volume in Volume in
Metric Centimeters Centimeters ccs or mL Liters1.9 3048 8641.70103 8.642
Enter flow rate (Q) in ml/min
500 1037.004 17.283
V = π x (d/2)2 x lTubing/Pipe Volume & Sample Delay
Delay time in seconds
Delay time in minutes
d
l
Q
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Crank it up to equal lower lag time?Crank it up to equal lower lag time?Big price to pay!Big price to pay!
Measurement Units (select
from list)Enter Diameter (d) in
Enter pipe or tubing length (l) in Volume in Volume in
Metric Centimeters Centimeters ccs or mL Liters1.9 3048 8641.70103 8.642
Enter flow rate (Q) in ml/min
35800 14.483 0.241
V = π x (d/2)2 x lTubing/Pipe Volume & Sample Delay
Delay time in seconds
Delay time in minutes
d
l
Q
35,800 ml/min = 9.46 gal/min35,800 ml/min = 9.46 gal/min = 13,622 gal/day= 13,622 gal/day
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Know Your ProcessKnow Your Process
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Know Your ProcessKnow Your Process
• Monitor Source WaterMonitor Source Water• Known variationsKnown variations
• SeasonalSeasonal• DiurnalDiurnal
• Unexpected upsetsUnexpected upsets• Spills/contaminationSpills/contamination• SecuritySecurity
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Know Your ProcessKnow Your Process
• Use lab and on-line instruments to Use lab and on-line instruments to understand the variables in chemical understand the variables in chemical additionaddition• pHpH
• PolymerPolymer
• DisinfectantDisinfectant
• FluorideFluoride
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Know Your ProcessKnow Your Process
• Jar tests can be invaluable Jar tests can be invaluable • Must simulate Must simulate youryour physical process physical process
• Helps to optimize coagulation which will Helps to optimize coagulation which will optimize the processoptimize the process
• Use lab test procedures for jar tests and Use lab test procedures for jar tests and validate process results with both lab and validate process results with both lab and on-line instrumentson-line instruments
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Know Your ProcessKnow Your Process
• Monitor distributionMonitor distribution• Yes, it really is part of the processYes, it really is part of the process
• Helps to maintain the water quality Helps to maintain the water quality throughout the system as good as it was throughout the system as good as it was coming out of the plantcoming out of the plant
• Monitor Corrosion ControlMonitor Corrosion Control
• Identify Potential Nitrification IssuesIdentify Potential Nitrification Issues
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Know Your ProcessKnow Your Process
• Baseline data must be establishedBaseline data must be established• The more you know about “normal” The more you know about “normal”
operations, the quicker you will discover operations, the quicker you will discover when it is abnormalwhen it is abnormal
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Analyze The DataAnalyze The Data• SCADASCADA
• Min, Max, AverageMin, Max, Average• TrendsTrends
• LIMSLIMS• Min, Max, AverageMin, Max, Average• TrendsTrends
• CombinationCombination• Software packages that can import from Software packages that can import from
both and analyze the databoth and analyze the data
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Specific Cost/EnergySpecific Cost/EnergySavings PointsSavings Points
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Major Monitoring PointsMajor Monitoring Points
• Source WaterSource Water
• Flocculation AidsFlocculation Aids
• Filter PerformanceFilter Performance• Filter EffluentFilter Effluent
• Filter to WasteFilter to Waste
• BackwashBackwash
• DisinfectionDisinfection
• DistributionDistribution
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MIXER
FLOCCULATOR
CLARIFIER
FILTERS
CLEARWELL
DisinfectantsHardnessTurbidity
pH
TurbiditypH
pH
WasteWater
BackwashTurbidity
TurbidityParticle MonitoringChlorine and / or
Permanganate and / orManganeseAluminum
pH
TurbidityDisinfectants
HardnessAlkalinity
pH
DRINKING WATER TREATMENT FLOW DIAGRAM
RawWater Effluent
TurbidityChlorineAlkalinity
Particle Monitoring
Distribution
Solids
Filter Effluent
SCM Recycle
Filter toWaste
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Source WaterSource Water
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Source WaterSource Water
• You need to know what the water quality You need to know what the water quality is coming into your plant before you can is coming into your plant before you can make any needed adjustments to it.make any needed adjustments to it.
• Baseline data is invaluable.Baseline data is invaluable.
• Many normal variations in water quality Many normal variations in water quality can easily be accommodated.can easily be accommodated.
• Serious changes can be identified and Serious changes can be identified and dealt with.dealt with.
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Source Water – Ground WaterSource Water – Ground Water• At the minimum, with on-line instrumentsAt the minimum, with on-line instruments
• pH (with temperature)pH (with temperature)• ORPORP• TurbidityTurbidity
• Additionally, with either lab or on-line Additionally, with either lab or on-line instrumentsinstruments• HardnessHardness• AlkalinityAlkalinity• OrganicsOrganics• NitratesNitrates• IronIron• ManganeseManganese
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Source Water – Surface WaterSource Water – Surface Water
• Many more parameters to be concerned Many more parameters to be concerned withwith
• Changes can happen much quicker than Changes can happen much quicker than with ground waterwith ground water
• Need to be able to respond to those Need to be able to respond to those changes rapidly to adjust your processchanges rapidly to adjust your process
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Source Water – Surface WaterSource Water – Surface Water
• pHpH• General, overall indicatorGeneral, overall indicator
• Seasonal variationsSeasonal variations• Fall turnoverFall turnover• Summer stratificationSummer stratification• Influence of precipitation eventsInfluence of precipitation events• Indicator of biological activityIndicator of biological activity• Indicator of industrial pollutionIndicator of industrial pollution
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Source Water – Surface WaterSource Water – Surface Water
• TurbidityTurbidity• Indicator of physical upset (rain,wind, etc)Indicator of physical upset (rain,wind, etc)
• Many contaminants adhere to particles (e.g. Many contaminants adhere to particles (e.g. phosphorous)phosphorous)
• High turbidity water is harder to treatHigh turbidity water is harder to treat
• Need to be able to respond quickly to Need to be able to respond quickly to changes in turbiditychanges in turbidity
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Source Water – Surface WaterSource Water – Surface Water• ConductivityConductivity
• Changes in ionic speciesChanges in ionic species
• ORPORP• Changes in oxidative or reducing speciesChanges in oxidative or reducing species
• OrganicsOrganics• Seasonal changes and contaminationSeasonal changes and contamination
• AmmoniaAmmonia• Biological degradationBiological degradation
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Source Water – Surface WaterSource Water – Surface Water
• NitrateNitrate• Level of nutrients and ag runoffLevel of nutrients and ag runoff
• DODO• Seasonal and diurnal changes due to algae Seasonal and diurnal changes due to algae
and other aquatic plantsand other aquatic plants
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Source Water Monitoring PanelSource Water Monitoring Panel
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Flocculation AidsFlocculation Aids
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Flocculation AidsFlocculation Aids
• Proper dosing of flocculation aids Proper dosing of flocculation aids (polymer, alum, ferric chloride, etc) will (polymer, alum, ferric chloride, etc) will optimize your processoptimize your process
• Under-dosing results in poor floc Under-dosing results in poor floc formationformation
• Over-dosing is expensiveOver-dosing is expensive
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Flocculation AidsFlocculation Aids
• Laboratory jar Laboratory jar tests are tests are invaluable as invaluable as long as the long as the apparatus is apparatus is representative of representative of your processyour process
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Flocculation AidsFlocculation Aids
• Controlling the dose correctly is the keyControlling the dose correctly is the key
• Parameters to monitorParameters to monitor• Turbidity can be used to track dosingTurbidity can be used to track dosing
• pH is also an important parameter to trackpH is also an important parameter to track
• Streaming Current is generally one of the Streaming Current is generally one of the best methods of measuring effectiveness of best methods of measuring effectiveness of dosedose
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Streaming CurrentStreaming Current
• On-line measurement of how well charge On-line measurement of how well charge neutralization has occurredneutralization has occurred
• Influenced by salinity, pH and Influenced by salinity, pH and conductivityconductivity
• Sample point must be close to the point Sample point must be close to the point of injection but after it is well mixedof injection but after it is well mixed
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Streaming Current MonitorStreaming Current Monitor
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Monitoring Filter Monitoring Filter TurbidityTurbidity
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Monitoring Filter TurbidityMonitoring Filter Turbidity
• Three points of turbidity monitoring Three points of turbidity monitoring • Filter effluentFilter effluent
• Filter to wasteFilter to waste
• BackwashBackwash
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Filter Effluent TurbidityFilter Effluent Turbidity
• Monitors filter performanceMonitors filter performance
• Provides the method of meeting Provides the method of meeting regulatory requirementsregulatory requirements• ““15 Minute Rule”15 Minute Rule”
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The “15 Minute Rule”The “15 Minute Rule”
• Must conduct continuous monitoring of Must conduct continuous monitoring of turbidity for each filter using an turbidity for each filter using an approved method.approved method.
• Must calibrate turbs using the procedure Must calibrate turbs using the procedure specified by the manufacturer.specified by the manufacturer.
• Must record the results every 15 Must record the results every 15 minutes while the filter is contributing to minutes while the filter is contributing to the combined filter effluent.the combined filter effluent.
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Combined Filter Effluent Combined Filter Effluent TurbidityTurbidity
• Must be monitored at least every 4 Must be monitored at least every 4 hours.hours.
• Must be less than or equal to 0.3 NTU in Must be less than or equal to 0.3 NTU in at least 95% of the measurements taken at least 95% of the measurements taken each month.each month.
• Must not exceed 1 NTU at any time.Must not exceed 1 NTU at any time.
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Filter PerformanceFilter PerformanceTurbidity vs. Particle CounterTurbidity vs. Particle Counter
• Like turbidity, particle counting is another Like turbidity, particle counting is another tooltool
• They are complimentary and They are complimentary and notnot competing technologiescompeting technologies
• Each can tell part of the whole pictureEach can tell part of the whole picture
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Turbidity Measurement Particle Count Measurement
Measurement of light scattered at an angle. For municipal water/wastewater applications light scattering measurements at 90º to the incident light path.
Particle counting measurements can be light scattering or light blocking. Light scattering technology is appropriate for particle sizes <1µm. Light blocking technology is appropriate for particle sizes > 1µm. For municipal drinking water applications, light blocking > 1µm (typically >2µm) is appropriate.
Not a specific measurement of anything, it is a qualitative measurement
A quantitative measurement of particle size and particle number.
Measurement is independent of volume
Measurement is volume dependent
Measurement is relatively independent of flow rate. Sample can be flowing or static
Sample must be flowing and flowing at a constant rate.
Unit of measurement is nephelometric turbidity units, NTU
Unit of measurement is particle counting must state the number of particles, particle size or range of sizes and unit volume. For example 10 particles per ml > 5µm or 200 particles per ml 2-5µm.
Peak wavelength response for lab, SS7 and 1720 series process is ~560nm, FT660 is 660 nm, for Accu4 ~ 850nm
Wavelength is 790 nm
Theoretical particle size sensitivity 10-8m (0.01µm)
2200 PCX sensitivity is > 2µm
Turbidity Measurement Particle Count Measurement
Size range from approximately 10-8m - 10-3m (large molecules to sand)
For the 2200 PCX: 2-750 µm
Color in water is a negative interference except for the Accu 4
Color does not interfere with particle count measurements
Turbidity interferes. High turbidity is a negative interference. At high turbidity scattered light is blocked or absorbed by the large amount of turbidity and thus does not reach the detector. The turbidity will be false negative. This phenomenon is called ‘going blind.’
Turbidity interferes. High turbidity is a negative interference. Particle counters typically have a range of approximately 17,000 particles/ml > 2µm. The particle counter may be over range at turbidity between 1 and 10 NTU – typically approximately 5 NTU. The particle counts will be false negative.
Light absorbing materials (i.e. activated carbon) are negative interferences.
Light absorbing materials (i.e. carbon) block light well and thus are counted. They do not interfere
Accuracy of measurement is influenced by particle size
Accuracy of measurement is influenced by particle size
Accuracy of measurement is influenced by particle shape
Accuracy of measurement is influenced by particle shape
Accuracy of measurement is influenced by a particle’s refractive index
Accuracy of measurement is influenced by particle’s refractive index
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Particle Particle Sizes Sizes
Practical Practical MeasurementMeasurement
Siz
e in
Me
ters
100
10-10
10-6
1 Meter-Boulders
1 AngstromIons
Bacteria/Silt & Clay
Viruses/Colloids
Sand
Multicell Organisms
Visible
Microscope
Electron Microscope
TurbidityParticle Counting
10-3
10-8
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Turbidity vs. Particle CounterTurbidity vs. Particle Counter
• What follows are examples of how they What follows are examples of how they compliment each othercompliment each other
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1720C and PCX-10 Response to Fluoride and Carbon1720C and PCX-10 Response to Fluoride and Carbon
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Date/Time
Pa
rtic
les/
mL
PC
X-1
0 S
en
sor:
>1
µm
an
d >
2µ
m
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Effluent PCX-10:>1µm Effluent PCX-10:>2 µm Effluent Turbidity, NTU
Tu
rbid
ity, NT
U
1µ PCX-10 Sensor >2µm, left axis
Turbidity, NTU, right axis
1µ PCX-10 Sensor >2µm, left axis
By 17:00 Filters 3 and 6 in service 100 hrs and 72 hrs, respectively.
Filter 4 in service
75
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Effluent PCX-10:>1µm Effluent PCX-10:>2 µm Effluent Turbidity, NTU
Tu
rbid
ity, NT
U
1µ PCX-10 Sensor >2µm, left axis
Turbidity, NTU, right axis
1µ PCX-10 Sensor >2µm, left axis
By 17:00 Filters 3 and 6 in service 100 hrs and 72 hrs, respectively.
Filter 4 in service
• About 9:21 AM both PCX and 1720C showed a deviationAbout 9:21 AM both PCX and 1720C showed a deviation
• Turb from 0.04 to 0.06 NTUTurb from 0.04 to 0.06 NTU
• PCX jumped over a decade on both channelsPCX jumped over a decade on both channels
• Delta in turb readings seem insignificant but did respondDelta in turb readings seem insignificant but did respond
• PCX definitely saw somethingPCX definitely saw something
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4:21
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9:21
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0:11
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rtic
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X-1
0 S
en
sor:
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µm
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d >
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m
0.00
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0.06
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Effluent PCX-10:>1µm Effluent PCX-10:>2 µm Effluent Turbidity, NTU
Tu
rbid
ity, NT
U
1µ PCX-10 Sensor >2µm, left axis
Turbidity, NTU, right axis
1µ PCX-10 Sensor >2µm, left axis
By 17:00 Filters 3 and 6 in service 100 hrs and 72 hrs, respectively.
Filter 4 in service
• What happened?What happened?
• Out of spec sodium silicofluoride (large particle size) was also contaminated with Out of spec sodium silicofluoride (large particle size) was also contaminated with activated carbon, hit the system at about 9:20 AMactivated carbon, hit the system at about 9:20 AM
• PC responded strongly to both the fluoride particles and carbon particlesPC responded strongly to both the fluoride particles and carbon particles
• Turb saw the fluoride particles as turbidity, but carbon particles are a negative Turb saw the fluoride particles as turbidity, but carbon particles are a negative interference. That made the response much less in intensity. interference. That made the response much less in intensity. MostMost turbs do not turbs do not have the low range resolution to show a significant response.have the low range resolution to show a significant response.
77
Particle Counter vs. Laser TurbParticle Counter vs. Laser Turb
• Laser Turb particle size sensitivity down to 0.01 Laser Turb particle size sensitivity down to 0.01 µmµm
• Resolution in mNTU (1.0 mNTU = 0.001 NTU)Resolution in mNTU (1.0 mNTU = 0.001 NTU)
• Particle counter size sensitivity at > 2 µmParticle counter size sensitivity at > 2 µm
78
Particle Counter vs. Laser TurbParticle Counter vs. Laser Turb
• Both track fairly well togetherBoth track fairly well together
• The FT660 show longer time to ripen after filter run. FT660 is still The FT660 show longer time to ripen after filter run. FT660 is still seeing the particles < 2 µmseeing the particles < 2 µm
• Particle counter does not respond to particles < 2 µmParticle counter does not respond to particles < 2 µm
• FT660 definitely responds to an anomaly that the Particle counter FT660 definitely responds to an anomaly that the Particle counter does not. Again probably because of particle size.does not. Again probably because of particle size.
79
Particle Counter vs. Laser TurbParticle Counter vs. Laser Turb
• Notice that the change in the FT660 at the event is from about 24 to Notice that the change in the FT660 at the event is from about 24 to 31 (7) mNTU’s. That is a significant number.31 (7) mNTU’s. That is a significant number.
• If it were a 1720E (or C or D) that would be a change of 0.007 NTU. If it were a 1720E (or C or D) that would be a change of 0.007 NTU. You probably would not even see it, let alone think it was significant.You probably would not even see it, let alone think it was significant.
80
81
Particle Counter DataParticle Counter Data• A particle counter is an excellent tool to A particle counter is an excellent tool to
judge filter performancejudge filter performance
• BUT, you must be willing to analyze the BUT, you must be willing to analyze the data…and there is a lot of it!data…and there is a lot of it!
• Data Data acquisitionacquisition is inadequate, it must is inadequate, it must become data become data analysisanalysis..
• Data acquired without a plan for, or Data acquired without a plan for, or means of use, is not of much value.means of use, is not of much value.
82
Monitoring Filter TurbidityMonitoring Filter Turbidity
• Three points of turbidity monitoring Three points of turbidity monitoring • Filter effluentFilter effluent
• Filter to wasteFilter to waste
• BackwashBackwash
83
Filter To WasteFilter To Waste• After backwash each filter’s water is run to waste After backwash each filter’s water is run to waste
until the filter ripens enough to bring it back on lineuntil the filter ripens enough to bring it back on line• Measuring the FTW turbidity is the best method of Measuring the FTW turbidity is the best method of
controlling when to bring the filter on linecontrolling when to bring the filter on line• If the FTW turbidity is less than the raw water but If the FTW turbidity is less than the raw water but
more than the allowed filter effluent, the water could more than the allowed filter effluent, the water could be recycled until the turbidity is low enough to bring be recycled until the turbidity is low enough to bring the filter on line.the filter on line.
• Difficult to do with grab samplesDifficult to do with grab samples• Must be done with a process turbMust be done with a process turb
84
Monitoring Filter TurbidityMonitoring Filter Turbidity
• Three points of turbidity monitoring Three points of turbidity monitoring • Filter effluentFilter effluent
• Filter to WasteFilter to Waste
• BackwashBackwash
85
The Importance of Backwash The Importance of Backwash Monitoring for TurbidityMonitoring for Turbidity
• Backwashing requires a significant Backwashing requires a significant volume of (already treated) water (3 - volume of (already treated) water (3 - 5% or more).5% or more).
• The most common problem is excessive The most common problem is excessive backwash.backwash.
• This can have a dramatic impact on This can have a dramatic impact on • filter performancefilter performance• plant operating costsplant operating costs
86
The Importance of Backwash The Importance of Backwash Monitoring for TurbidityMonitoring for Turbidity
• Excessive backwash can lead toExcessive backwash can lead to• Loss of filter mediaLoss of filter media
• A negative effect on the ripening phaseA negative effect on the ripening phase
• Shortened filter runsShortened filter runs
• Higher potential for filter break throughsHigher potential for filter break throughs
• Degraded filter performanceDegraded filter performance
87
The Importance of Backwash The Importance of Backwash Monitoring for TurbidityMonitoring for Turbidity
• To optimize filter performance:To optimize filter performance:
REDUCE BACKWASHING!REDUCE BACKWASHING!
88
The Importance of Backwash The Importance of Backwash Monitoring for TurbidityMonitoring for Turbidity
• Methods used for determining Methods used for determining termination of the backwash cycle termination of the backwash cycle include:include:• Timed cycleTimed cycle
• Backwash volume Backwash volume
• Operator judgementOperator judgement
• TurbidityTurbidity
89
Methods for Backwash Methods for Backwash Termination: Timed CycleTermination: Timed Cycle
• Backwash cycle is just timedBackwash cycle is just timed• Not a true indicator of filter cleaningNot a true indicator of filter cleaning
• Does not take into account:Does not take into account:• Solids loadingSolids loading• Changes in the mediaChanges in the media• Variations in flowVariations in flow
• Typically, excess water is used to Typically, excess water is used to ensure the filter is clean.ensure the filter is clean.
90
Methods for Backwash Methods for Backwash Termination: Backwash VolumeTermination: Backwash Volume• A specific amount of water is used to A specific amount of water is used to
backwash the filterbackwash the filter
• Same problems as with the timed cycleSame problems as with the timed cycle
• Typically, excess water is used to ensure Typically, excess water is used to ensure the filter is clean.the filter is clean.
91
Methods for Backwash Methods for Backwash Termination:Operator Termination:Operator
JudgementJudgement• Operator “eye-balls” the top of the filter to Operator “eye-balls” the top of the filter to
determine when the backwash is done.determine when the backwash is done.
• The obvious:The obvious:• Un-scientific Un-scientific
• InconsistentInconsistent
• Often results in over-washing the filter.Often results in over-washing the filter.
92
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Methods for Backwash Methods for Backwash Termination: TurbidityTermination: Turbidity
• Turbidimetric measurements are made Turbidimetric measurements are made throughout the cyclethroughout the cycle
• Determination of the end-point is:Determination of the end-point is:• Based on good scienceBased on good science
• RepeatableRepeatable
• Independent of filter loading and variationsIndependent of filter loading and variations
• Un-biasedUn-biased
94
Methods for Backwash Methods for Backwash Termination:TurbidityTermination:Turbidity
• Studies have shown that the final Studies have shown that the final turbidity at the termination of a turbidity at the termination of a backwash cycle directly correlates backwash cycle directly correlates to subsequent filter performance to subsequent filter performance and run time.and run time.
95
Methods for Backwash Methods for Backwash Termination: TurbidityTermination: Turbidity
• AWWA recommends backwash be AWWA recommends backwash be terminated when the turbidity is in the terminated when the turbidity is in the range of 10 - 15 NTUrange of 10 - 15 NTU
• When done so, sufficient particulate When done so, sufficient particulate material remains above the filter to material remains above the filter to create the proper environment for an create the proper environment for an effective ripening period, which results effective ripening period, which results in longer and more effective filter runs.in longer and more effective filter runs.
96
AWWA Recommended Backwash Limit (10 - 15 NTU)
97
0
5
10
15
20
25
3:0
2
3:0
2
3:0
3
3:0
4
3:0
4
3:0
5
3:0
5
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6
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1
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5
Start
End
A 3:13
B 3:15
Large Filter with aLarge Filter with a17,000 gpm BW Rate17,000 gpm BW Rate
98
Methods for Backwash Methods for Backwash Termination:TurbidityTermination:Turbidity
• Methods for measuring backwash Methods for measuring backwash turbidityturbidity• Grab sampleGrab sample
• Must be representative sampleMust be representative sample• Time and labor intensiveTime and labor intensive• Requires many samples per filter runRequires many samples per filter run
• On-lineOn-line• Slip-stream (traditional)Slip-stream (traditional)• In situIn situ
99
In situIn situ Analysis for Backwash Analysis for Backwash TurbidityTurbidity
• Use a probe designUse a probe design• The probe is placed in backwash The probe is placed in backwash
troughtrough• Extremely rapid response to changes Extremely rapid response to changes
in backwash turbidityin backwash turbidity• Measurements are taken at frequent Measurements are taken at frequent
intervalsintervals
100
Instrumental MonitoringInstrumental Monitoring• AdvantagesAdvantages
• Consistent Consistent operationoperation
• Automated Automated monitoringmonitoring
• All operators “see” All operators “see” the same thingthe same thing
• Better overall Better overall process control to process control to lower costslower costs
• DisadvantagesDisadvantages• Initial instrument Initial instrument
purchasepurchase
• Installation costsInstallation costs
• Operators may feel Operators may feel threatenedthreatened
101
Instrumental MonitoringInstrumental Monitoring
• Nearly every utility implementing Nearly every utility implementing instrumental backwash monitoring can instrumental backwash monitoring can achieve cost savings equal to the achieve cost savings equal to the installed cost of the instruments in a year installed cost of the instruments in a year or lessor less
102
Location – Time is Money!Location – Time is Money!• Analysis needs to be taken as close to the Analysis needs to be taken as close to the
backwash as practical – seconds are backwash as practical – seconds are importantimportant
• If possible mount in the BW trough If possible mount in the BW trough
• CAUTION:CAUTION: Poor response and little or no Poor response and little or no savings may result if mounted as follows:savings may result if mounted as follows:• Manifolding multiple filters to a single Manifolding multiple filters to a single
monitoring sensor or point monitoring sensor or point
• Sampling the common drain line of drain galley Sampling the common drain line of drain galley or gulletor gullet
103
Typical Installation Typical Installation ConfigurationConfiguration
• Many Many controllers controllers accept inputs accept inputs from two from two probesprobesOne Sensor in
Backwash Trough
104
105
Monitor Uniformity of BackwashMonitor Uniformity of Backwash
• Use a second Use a second sensor mounted sensor mounted on a pole (1/2-on a pole (1/2-3/4” pipe or rigid 3/4” pipe or rigid conduit) to move conduit) to move around the filter around the filter to check to check uniformity of uniformity of washingwashing
106
Sensor Mounted in Filter BedSensor Mounted in Filter Bed
• Use pipe-mounted Use pipe-mounted sensor to move sensor to move around filteraround filter
Sensor
Sensor Mounting
107
Sensor Mounted in TroughSensor Mounted in Trough• Sensor mounted Sensor mounted
in backwash in backwash trough – more trough – more representativerepresentative
• Sensor points Sensor points upstream, into upstream, into the flowthe flow
• Mount near Mount near bottom of troughbottom of trough
108
Self-cleaning WiperSelf-cleaning Wiper
• Self-cleaning Self-cleaning • Adjustable wiping Adjustable wiping
frequencyfrequency
• Long wiper blade Long wiper blade lifelife
109
Typical Data From BW Typical Data From BW MonitoringMonitoring
110
Noisy ResponseNoisy Response
• Some samples may be noisy and require Some samples may be noisy and require sample conditioning with a stilling chambersample conditioning with a stilling chamber
111
Stilling Chamber to Quiet NoiseStilling Chamber to Quiet Noise
• Black PVC pipeBlack PVC pipe
• 6 feet long, 8 6 feet long, 8 inch diameterinch diameter
• Used to ‘quiet’ Used to ‘quiet’ the samplethe sample
112
After Installation of Stilling After Installation of Stilling ChamberChamber
113
Large FiltersLarge FiltersFilter Side A Filter Side B
BW Trough/Launderer BW Trough/Launderer
BW Trough/Launderer BW Trough/Launderer
BW Trough/LaundererBW Trough/Launderer
Flo
w
Common Drain Gullet Mount Permanent Probe here to look into the stream
Use second probe to move around the filter to assess uniformity of backwash
114
Manifold/Drain Header Mounting Manifold/Drain Header Mounting
• Avoid where possibleAvoid where possible• Unacceptable delayUnacceptable delay
• Non-representative samplingNon-representative sampling
Sensor
Filter 1 Filter 2 Filter 3 Filter 4 Filter 5 Filter 6
Manifold/Drain Header
115
Summary of Backwash Summary of Backwash MonitoringMonitoring
• Consistent Filter BackwashConsistent Filter Backwash• Filter to FilterFilter to Filter• Operator to OperatorOperator to Operator
• Reduced Power CostReduced Power Cost• Reduced Water ConsumptionReduced Water Consumption• More Saleable WaterMore Saleable Water• Lower Re-treatment CostLower Re-treatment Cost• Lower Filter to Waste Cost and VolumeLower Filter to Waste Cost and Volume• Lower Backwash Recovery CostsLower Backwash Recovery Costs
116
Case Study: Backwash Profiling Case Study: Backwash Profiling at a Colorado Water Treatment at a Colorado Water Treatment
PlantPlant• 38 MGD38 MGD• 12 Filter beds12 Filter beds• Coagulation, sedimentation and filtrationCoagulation, sedimentation and filtration• Conventional dual-media filter designConventional dual-media filter design• Filter run averages 24 hoursFilter run averages 24 hours• Raw water 10 - 20 NTURaw water 10 - 20 NTU• Settled water 1 - 2 NTUSettled water 1 - 2 NTU• Final effluent rarely exceeds 0.030 NTUFinal effluent rarely exceeds 0.030 NTU
117
Case Study: Backwash Profiling Case Study: Backwash Profiling at a Colorado Water Treatment at a Colorado Water Treatment
PlantPlant
• The plant is a member of the Partnership The plant is a member of the Partnership for Safe Drinking Water and consistently for Safe Drinking Water and consistently exceeds their membership requirements.exceeds their membership requirements.
118
Case Study: Backwash Profiling Case Study: Backwash Profiling at a Colorado Water Treatment at a Colorado Water Treatment
PlantPlant• To profile the filters, the probeTo profile the filters, the probe
• was mounted 4 feet below the water linewas mounted 4 feet below the water line
• 18 inches above the filter media18 inches above the filter media
• facing away from the filter wallfacing away from the filter wall
• in a horizontal positionin a horizontal position
119
Case Study: Backwash Profiling Case Study: Backwash Profiling at a Colorado Water Treatment at a Colorado Water Treatment
PlantPlant
• Data collection at 5 second intervalsData collection at 5 second intervals
• 30 second signal averaging to reduce 30 second signal averaging to reduce noise levels due to turbulence above the noise levels due to turbulence above the filter mediafilter media
120
121
Surface Wash On
4,000 gpm
6,000 gpm
Surface Wash Off
Surface Wash On 3,900 gpm
Surface Wash Off 6,000gpm
5,300 gpm
2,000 gpm
122
Case Study: Backwash Profiling Case Study: Backwash Profiling at a Colorado Water Treatment at a Colorado Water Treatment
PlantPlant• The profile shows two distinct peaksThe profile shows two distinct peaks
• Cycle begins with surface washCycle begins with surface wash
• Max turbidity (55 NTU) at 6000 gpm (1Max turbidity (55 NTU) at 6000 gpm (1OO))
• Within 6 minutes turbidity drops below 5 Within 6 minutes turbidity drops below 5 NTUNTU
• Second SW brings it up to 15 NTU (2Second SW brings it up to 15 NTU (2OO))
• Backwash flow rate is then slowly reducedBackwash flow rate is then slowly reduced
123
Case Study: Backwash Profiling Case Study: Backwash Profiling at a Colorado Water Treatment at a Colorado Water Treatment
PlantPlant• At nine minutes turbidity is between 1 At nine minutes turbidity is between 1
- 2 NTU- 2 NTU• Same as settled water prior to filtrationSame as settled water prior to filtration
• After almost 14 minutes final turbidity After almost 14 minutes final turbidity is 0.081 NTUis 0.081 NTU
124
Case Study: Backwash Profiling Case Study: Backwash Profiling at a Colorado Water Treatment at a Colorado Water Treatment
PlantPlant• ConclusionsConclusions
• The filter was over-washed (0.081 vs 10 - 15 The filter was over-washed (0.081 vs 10 - 15 NTU)NTU)
• AWWA would recommend terminating BW during AWWA would recommend terminating BW during second Surface Wash peak (15 NTU at 7 min)second Surface Wash peak (15 NTU at 7 min)
• If longer runs are desired, could terminate BW at If longer runs are desired, could terminate BW at about 9 minutes when turbidity was equal to that about 9 minutes when turbidity was equal to that of settled water.of settled water.
125
Case Study: Backwash Profiling Case Study: Backwash Profiling at a Colorado Water Treatment at a Colorado Water Treatment
PlantPlant• Conclusions (continued)Conclusions (continued)
• In either case a substantial amount of BW water In either case a substantial amount of BW water could be saved. (30% – 45%) = $$$$$$could be saved. (30% – 45%) = $$$$$$
• Although subsequent filter runs were not Although subsequent filter runs were not documented in this case, other studies have documented in this case, other studies have shown an increase in filter runs and quicker shown an increase in filter runs and quicker ripening of the filter.ripening of the filter.
• Process optimization is the ultimate goalProcess optimization is the ultimate goal
126
Will I Always Save?Will I Always Save?• WaterWater
• No. Under washing and over washing No. Under washing and over washing are both problems. If under washing has are both problems. If under washing has been a problem for very long, it will take been a problem for very long, it will take a while to clean the filter(s) up. a while to clean the filter(s) up. THEN THEN water savings will start.water savings will start.
• Operation ExpenseOperation Expense• Yes. Savings in power, re-treatment Yes. Savings in power, re-treatment
costs of water, labor, filter media, will costs of water, labor, filter media, will yield net savings.yield net savings.
127
Sample Calculations of Sample Calculations of SavingsSavings
128
Calculate BW Costs (Savings)Calculate BW Costs (Savings)• Calculate Cost of Backwash:Calculate Cost of Backwash:
• The Cost of OperationsThe Cost of Operations(A)(A) = =
$ Cost of Operation(A) X 1000 Gallons Saved(B) = $ Saved1000 Gallons Backwash Cycle Backwash Cycle
Total Annual Budget $* = $ Cost of Operation1000 Gallons Produced Annually 1000 Gallons
*All costs – debit service, salaries, benefits, utilities, chemicals, maintenance, depreciation, capital expenses, consulting fees
129
Calculate BW Costs (Savings)Calculate BW Costs (Savings)
• Example Cost of Operation Example Cost of Operation (A)(A)::
• The Cost of OperationsThe Cost of Operations(A)(A) = =
$ Total annual budget = $ Cost of Operation1000 Gallons annually 1000 gallons
$18,000,000 Annual Budget = $ 3.654,900,000,000 Gallons Produced Annually 1000 gallons
130
Calculate BW Costs (Savings)Calculate BW Costs (Savings)
• Calculate Dollars saved per Backwash:Calculate Dollars saved per Backwash:
• So,in1000 gallons saved/backwash cycle So,in1000 gallons saved/backwash cycle (B(B)=)=
$ 3.65 (A) X 1000 Gallons saved (B) = $ Saved1000 Gallons Backwash Cycle Backwash Cycle
1000 gallons (max rate) X Minutes Saved Minute Backwash Gallons
131
Calculate BW Costs (Savings)Calculate BW Costs (Savings)
• Savings per backwash Savings per backwash (B):(B):
• So, assume 4,000 gal/minute rate, 1.5 minutes So, assume 4,000 gal/minute rate, 1.5 minutes saved/backwash cost of water will be:saved/backwash cost of water will be:
$ 3.65 (A) X 1000 Gallons saved (B) = $ Saved 1000 Gallons Backwash Cycle Backwash Cycle
4,000 gallons X 1.5 Minutes Saved X $3.65 (A) = $21.90Minute Wash 1000 Gal Wash
132
Calculate BW Costs (Savings)Calculate BW Costs (Savings)
• Savings in Wash water Savings in Wash water (B):(B):
• So, assume 4 filters, 60 hr runtimes; 8,760 hours in So, assume 4 filters, 60 hr runtimes; 8,760 hours in a year so each filter will be washed 146 timesa year so each filter will be washed 146 times
$ 3.65 (A) X 6000 Gallons saved (B) = $ 21.901000 Gallons Backwash Cycle Backwash Cycle
$21.90 X 146 washes X 4 filters = $12,789.60 Wash Filter Year
133
Calculate Savings and Calculate Savings and Revenue in BWRevenue in BW
• Savings from saved water:Savings from saved water:
• Savings from treating or retreating replacement Savings from treating or retreating replacement water – water – Numerically the same as above = $Numerically the same as above = $12,789.60
$21.90 X 146 washes X 4 filters = $12,789.60 Wash Filter Year
134
Calculate Savings and Calculate Savings and Revenue in BWRevenue in BW
• Savings from saved water per year:Savings from saved water per year:• figured already = $12,789.60figured already = $12,789.60
• Savings from treating or retreating Savings from treating or retreating replacement water – $ 12,789.60 same replacement water – $ 12,789.60 same as aboveas above
• Total savings from saved and Total savings from saved and retreating water = retreating water = $25,579.20$25,579.20
135
Calculate Savings and Calculate Savings and Revenue in BWRevenue in BW
Revenue Value of Water Saved:Revenue Value of Water Saved:
$Price$Price X 1000 Gallons Saved = $ Revenue X 1000 Gallons Saved = $ Revenue 1000 Gallons1000 Gallons
1.5 mintues x 4000 gal/min = 6, 000 gallons/wash1.5 mintues x 4000 gal/min = 6, 000 gallons/washor or 3,504,000 gallons per year3,504,000 gallons per year (6000x146x4) (6000x146x4)
Water Water raterate = $3.75/1000 = = $3.75/1000 = $13,140 Revenue $13,140 Revenue valuevalue
136
Calculate Savings in Power for Calculate Savings in Power for Pumps and BlowersPumps and Blowers
• Calculate power use for pump or blower Calculate power use for pump or blower (air wash or air scour)(air wash or air scour)KW* Used X Hours of Pumping X Dollars = Dollars
Backwash KWH* Backwash
*KW = Kilowatt; KWH = Kilowatt Hour. Calculate KW from motor name plate from - KVolts X rated Amps of motor.
137
Calculate Savings in Power for Calculate Savings in Power for Pumps and BlowersPumps and Blowers
• Calculate power use for pump or blower Calculate power use for pump or blower (air wash or air scour)(air wash or air scour)
• Example of 1.5 minutes/backwash savingsExample of 1.5 minutes/backwash savings• 60 HP PUMP AT 24kw ONLY PUMP USED60 HP PUMP AT 24kw ONLY PUMP USED
• Utility pays $0.07 per KWHUtility pays $0.07 per KWH
• 1.5/60 = hours of pumping1.5/60 = hours of pumping
24 KW X 0.025 Hours of Pumping X $0.07 = $0.042 Backwash KWH Backwash
138
Calculate Savings in Power for Calculate Savings in Power for Pumps and BlowersPumps and Blowers
• Calculate power use for pump or blower Calculate power use for pump or blower (air wash or air scour)(air wash or air scour)
• Example of $.042 /backwash savingsExample of $.042 /backwash savings• $0.042 x 146 backwashes/filter/year = $6.13 / Filter$0.042 x 146 backwashes/filter/year = $6.13 / Filter
• $6.13 / Filter x 4 = $24.52 per year$6.13 / Filter x 4 = $24.52 per year
24 KW X 0.025 Hours of Pumping X $0.07 = $0.042 Backwash KWH Backwash
139
Summary of SavingsSummary of Savings• Savings from using less waterSavings from using less water
• Washwater savedWashwater saved $ 12,789.60$ 12,789.60• Retreatment savedRetreatment saved $ 12,789.60 $ 12,789.60
• Savings in Power CostSavings in Power Cost• Backwash pumpBackwash pump $25 $25• Surface wash $10Surface wash $10• Waste return $ 5Waste return $ 5• Other pumpsOther pumps
• Savings in laborSavings in labor• Reduced by the percent reductionReduced by the percent reduction
of pump usage (eg 15 hrs) X labor costof pump usage (eg 15 hrs) X labor cost• TOTAL DIRECT ANNUAL SAVINGSTOTAL DIRECT ANNUAL SAVINGS > >$25,619.20$25,619.20
140
Summary of SavingsSummary of Savings• Total Direct Annual Savings Total Direct Annual Savings $25,604.20$25,604.20
• Indirect Annual savingsIndirect Annual savings• Revenue from water savedRevenue from water saved $13,140$13,140
• Water saved/yearWater saved/year3,504,0003,504,000 gal gal
141
1 Calculate cost per thousand gallons Notes:
a Total Annual BudgetInclude salaries, benefits, debt service, capital expenses, maintenance - the bottom line.
Average daily production in gallonsb 1000's of gallons produced annually 0
Cost of Operation per 1000 gallons = #DIV/0!
2 Calculate water savings per backwasha Backwash flow rate in 1000's/min 0 5,500 gal/min = 5.5 K gal/minb Enter minutes saved in backwash 0
1000's of Gallons saved per backwash 0
3 Calculate dollar savings per backwash1000's of gallons saved (line B10 above) 0Cost of Operation per 1000 gallons (line C5 above) #DIV/0!
Dollars saved per backwash #DIV/0!
4 Calculate annual savings in backwashNumber of FiltersAverage Filter run in hoursAverage number of backwashes per year #DIV/0!
Cost savings per year #DIV/0!Water savings per year in gallons #DIV/0!
Calculate annual savings in retreatment/replacement water treatment costs #DIV/0!
Equal to line C22
5 Calculate Pumping Cost for each pump
Backwash PumpKVA (KW) From motor name plateMinutes of pumping saved per backwash 0.00Hours of pumping saved per year #DIV/0!Cost in $ per KWHDollars saved per backwash $0.000Dollars saved per year #DIV/0!
Surface Wash PumpKVA (KW) From motor name plateMinutes of pumping saved per backwashHours of pumping saved per year #DIV/0!Cost in $ per KWH $0.000Dollars saved per backwash $0.000Dollars saved per year #DIV/0!
Backwash Return PumpKVA (KW) From motor name plateMinutes of pumping saved per backwashHours of pumping saved per year #DIV/0!Cost in $ per KWH $0.000Dollars saved per backwash $0.000Dollars saved per year #DIV/0!
Calculate Potential Savings in Backwash All gray-shaded cells are self-calculating and locked to protect them from inadvertent change. Enter the proper values for your treatment plant in the
yellow cells (column B). Enter notes as needed in white notes
142
Disinfection ControlDisinfection Control
143
Disinfection ControlDisinfection Control
• OzoneOzone
• Chlorine DioxideChlorine Dioxide
• ChloraminationChloramination
144
OzoneOzone
• Typically use ozone analyzer or ORP for Typically use ozone analyzer or ORP for feedback controlfeedback control
• Feed forward control usually done by Feed forward control usually done by measuring organic loadingmeasuring organic loading• TOCTOC
• UV-254UV-254
145
OzoneOzone
• Ozone is aggressive, volatile, and has a Ozone is aggressive, volatile, and has a short half-lifeshort half-life
• Very important to sample properlyVery important to sample properly• Correct sample tubing materialCorrect sample tubing material
• Shortest line possibleShortest line possible
• High velocity with proper volume to High velocity with proper volume to instrument instrument
146
OzoneOzone
““A short detention time is critical when ozone decay is A short detention time is critical when ozone decay is very rapid (i.e. ozone half-life is short). Sample very rapid (i.e. ozone half-life is short). Sample detention time is considered adequate if total ozone detention time is considered adequate if total ozone decay within the sample line is <10% for the worst-decay within the sample line is <10% for the worst-case condition, which is the most rapid ozone decay case condition, which is the most rapid ozone decay rate.” rate.”
(Rakness, (Rakness, Ozone in Drinking Water Treatment: Ozone in Drinking Water Treatment: Process Design, Operation and Optimization,Process Design, Operation and Optimization, AWWA 2005).AWWA 2005).
147
Ozone Residual Loss in Sample LineOzone Residual Loss in Sample Line
0
10
20
30
40
50
60
70
80
90
100
0 10 20 30 40 50 60 70 80 90 100 110 120
Detention Time in Sample Line, sec
% o
f A
ctua
l Ozo
ne R
esid
ual
HL = 0.5 min
HL = 1 min
HL = 2 min
HL = 4 min
Ozone Half-Life
0
10
20
30
40
50
60
70
80
90
100
0 10 20 30 40 50 60 70 80 90 100 110 120
Detention Time in Sample Line, sec
% o
f A
ctua
l Ozo
ne R
esid
ual
HL = 0.5 min
HL = 1 min
HL = 2 min
HL = 4 min
Ozone Half-Life
148
Chlorine DioxideChlorine Dioxide• Requires amperometric titration in lab for Requires amperometric titration in lab for
regulatory purposesregulatory purposes
• CLOCLO22
• ChloriteChlorite
• ChlorateChlorate
• Generator performanceGenerator performance
• On-line instruments provide the On-line instruments provide the monitoring necessary to assure CLOmonitoring necessary to assure CLO22
stays within limitsstays within limits
149
ChloraminationChloramination
• Must use the correct instrument for the Must use the correct instrument for the jobjob
• If you are making monochloramine then If you are making monochloramine then measure monochloraminemeasure monochloramine
• You cannot use a total chlorine test to You cannot use a total chlorine test to measure monochloraminemeasure monochloramine
• WHY?WHY?
150
ChloraminationChloramination
• Back to some basicsBack to some basics
• DefinitionsDefinitions• Total Chlorine = Free + CombinedTotal Chlorine = Free + Combined
• Combined Chlorine = (mostly) mono-, di- Combined Chlorine = (mostly) mono-, di- and trichloramineand trichloramine
• Free Chlorine = Hypochlorous acid (HOCL) Free Chlorine = Hypochlorous acid (HOCL) + hypochlorite ion (OCL+ hypochlorite ion (OCL--))
151
Chloramination CurveChloramination Curve
• Begin adding chlorine to water Begin adding chlorine to water containing ammoniacontaining ammonia• Initial addition of chlorine reacts to exhaust Initial addition of chlorine reacts to exhaust
any chlorine demand present in the waterany chlorine demand present in the water
152
Chlorination CurveChlorination Curve
Chlorine Added
Chl
orin
e M
easu
red
153
Chloramination CurveChloramination Curve
• Continue to add chlorine to the waterContinue to add chlorine to the water• After chlorine demand is exhausted, After chlorine demand is exhausted,
chlorine reacts with ammonia to form chlorine reacts with ammonia to form monochloraminemonochloramine
HOCl + NH3 NH2Cl + H2O
154
Chlorination CurveChlorination Curve
Chlorine Added
Chl
orin
e M
easu
red
ChloraminationChloramination
II
5:1 Cl2:N Ratio
155
Chloramination CurveChloramination Curve
• Continue to add chlorine to the waterContinue to add chlorine to the water• After complete formation of After complete formation of
monochloramine, monochloramine reacts monochloramine, monochloramine reacts with additional chlorine to form dichloramine with additional chlorine to form dichloramine and nitrogen trichloride.and nitrogen trichloride.
HOCl + NH2Cl NHCl2 + H2O
156
Chloramination CurveChloramination Curve
• Continue to add chlorine to the waterContinue to add chlorine to the water• As dichloramine and nitrogen trichloride As dichloramine and nitrogen trichloride
form, the addition of chlorine continues to form, the addition of chlorine continues to oxidize these compounds to nitrogen gasoxidize these compounds to nitrogen gas
• The point at which all dichloramine is The point at which all dichloramine is converted to nitrogen gas is the converted to nitrogen gas is the breakpointbreakpoint..
157
Chlorination CurveChlorination Curve
Chlorine Added
Chl
orin
e M
easu
red
ChloraminationChloramination
II
Breakpoint 9:1 Cl2:N Ratio
IIII
5:1 Cl2:N Ratio
158
Chloramination CurveChloramination Curve
• Continue to add chlorine to the waterContinue to add chlorine to the water• After the breakpoint, all chlorine added to After the breakpoint, all chlorine added to
the water remains as free chlorinethe water remains as free chlorine
• Breakpoint chlorinationBreakpoint chlorination
Cl2 + H2O HOCl + OCl-
159
Chlorination CurveChlorination Curve
Chlorine Added
Chl
orin
e M
easu
red
ChloraminationChloramination
II
Breakpoint 9:1 Cl2:N Ratio
IIII
5:1 Cl2:N Ratio
Free ChlorinationFree Chlorination
IIIIII
160
Chloramination GoalsChloramination Goals
• Complete formation of monochloramine Complete formation of monochloramine (stay in section I)(stay in section I)
• 3-5:1 Cl3-5:1 Cl22:N optimal feed ratio:N optimal feed ratio
• Avoid dichloramine formationAvoid dichloramine formation• Avoid taste and odor problemsAvoid taste and odor problems
• Minimize un-reacted ammoniaMinimize un-reacted ammonia• Control biofilm and nitrificationControl biofilm and nitrification
161
Chloramination SpeciesChloramination Species
• Curve we have been looking at is total Curve we have been looking at is total chlorinechlorine
• What other species are involved in What other species are involved in chloramination and what happens to chloramination and what happens to their concentrations?their concentrations?
162
Free AmmoniaFree Ammonia
• Free ammonia reacts with chlorine to Free ammonia reacts with chlorine to form monochloramine until ammonia has form monochloramine until ammonia has been consumedbeen consumed
163
Chloramination SpeciesChloramination Species
Chlorine Added
Chl
orin
e M
easu
red
ChloraminationChloramination
II IIII
Free ChlorinationFree Chlorination
IIIIII
Total Chlorine
Free Ammonia
164
MonochloramineMonochloramine
• Monochloramine is equivalent to total Monochloramine is equivalent to total chlorine until Section II where it reacts chlorine until Section II where it reacts with chlorine to form new compounds.with chlorine to form new compounds.
• No monochloramine remains at the No monochloramine remains at the breakpoint.breakpoint.
165
Chloramination SpeciesChloramination Species
Chlorine Added
Chl
orin
e M
easu
red
ChloraminationChloramination
II IIII
Free ChlorinationFree Chlorination
IIIIII
Total Chlorine
Free Ammonia
Monochloramine
166
Free ChlorineFree Chlorine
• Free chlorine does not exist until after Free chlorine does not exist until after the breakpoint.the breakpoint.
• After the breakpoint, all chlorine added to After the breakpoint, all chlorine added to the system exists as free chlorine.the system exists as free chlorine.
167
Chloramination SpeciesChloramination Species
Chlorine Added
Chl
orin
e M
easu
red
ChloraminationChloramination
II IIII
Free ChlorinationFree Chlorination
IIIIII
Total Chlorine
Free Ammonia
Monochloramine
Free Chlorine
168
ChloraminationChloramination
• So why can’t I use total chlorine to run So why can’t I use total chlorine to run my chloramination process?my chloramination process?
• Let’s look at the results of a total chlorine Let’s look at the results of a total chlorine test on the curve.test on the curve.
169
Where Am I When Where Am I When Total Chlorine = 3mg/L?Total Chlorine = 3mg/L?
Chlorine Added
Chl
orin
e M
easu
red
ChloraminationChloramination
II IIII
Free ChlorinationFree Chlorination
IIIIII
170
I Am Here!I Am Here!
Chlorine Added
Chl
orin
e M
easu
red
ChloraminationChloramination
II IIII
Free ChlorinationFree Chlorination
IIIIII
NHNH22Cl = t-DPDCl = t-DPD
f-NHf-NH33N > 0N > 0
NHNH22Cl < t-DPDCl < t-DPD
f-NHf-NH33N = 0N = 0
t-DPD > 0t-DPD > 0
NHNH22Cl = 0Cl = 0
f-NHf-NH33N = 0N = 0
171
ChloraminationChloramination
• Chose the right instrument for the jobChose the right instrument for the job
• Both lab and on-line instruments are Both lab and on-line instruments are available to measure and/or calculate:available to measure and/or calculate:• MonochloramineMonochloramine
• Total ChlorineTotal Chlorine
• Free ChlorineFree Chlorine
• Total AmmoniaTotal Ammonia
• Free AmmoniaFree Ammonia
172
ChloraminationChloramination
• Using the right instrument to measure Using the right instrument to measure these parameters will keep your process these parameters will keep your process in controlin control
• Upset conditions can be dealt with in a Upset conditions can be dealt with in a timely manner to minimize any negative timely manner to minimize any negative impactimpact
173
DistributionDistribution
174
DistributionDistribution
• Distribution monitoring is critical not only Distribution monitoring is critical not only for security, but also for performance for security, but also for performance reasons.reasons.
• The distribution system is a part of the The distribution system is a part of the process that has been overlooked.process that has been overlooked.
• The water leaving your plant may meet The water leaving your plant may meet all regulated requirements, but can all regulated requirements, but can change dramatically in distribution.change dramatically in distribution.
175
DistributionDistribution• There are many parameters that can There are many parameters that can
be monitored.be monitored.
• Through many studies, those deemed Through many studies, those deemed most important are:most important are:• pHpH
• ConductivityConductivity
• Chlorine (colorimetric)Chlorine (colorimetric)
• TurbidityTurbidity
• TOCTOC
176
DistributionDistribution• Several manufactures have developed Several manufactures have developed
“panels” that include these and other “panels” that include these and other parameters.parameters.
• You can build your own with discrete You can build your own with discrete instrumentsinstruments
• EPA suggests that at least 10 sampling points EPA suggests that at least 10 sampling points are needed throughout a system to be are needed throughout a system to be effectiveeffective
• The difficult part is interpreting all the dataThe difficult part is interpreting all the data
177
Guardian BlueGuardian Blue™™
• Off the shelf “hardware” and Off the shelf “hardware” and communicationscommunications
• Raw data available to SCADA systemRaw data available to SCADA system
• Contains a software algorithm that can Contains a software algorithm that can interpret,interpret, identifyidentify and and namename anomalies anomalies in the systemin the system
178
Guardian BlueGuardian Blue™™
• Hach Laboratory testing and verification.Hach Laboratory testing and verification.• EPA/Battelle Environmental Testing EPA/Battelle Environmental Testing
Verification (ETV) program testing and Verification (ETV) program testing and certification.certification.
• Army Edgewood Chemical and Biological Army Edgewood Chemical and Biological Command (ECBC) and Army Corps of Command (ECBC) and Army Corps of Engineers Engineer Research and Engineers Engineer Research and Development Center-Construction Engineering Development Center-Construction Engineering Research Laboratory(ERDC-CERL) Testing.Research Laboratory(ERDC-CERL) Testing.
• Real world deployment testing.Real world deployment testing.
179
All of this Led to DHS Safety Act All of this Led to DHS Safety Act ApprovalApproval
• The SAFETY act is part of the 2002 Homeland The SAFETY act is part of the 2002 Homeland Security Act. Security Act. SSupport upport AAnti-terrorism by nti-terrorism by FFostering ostering EEffective ffective TTechnologies Actechnologies Act
• Provides litigation protection for manufacturers Provides litigation protection for manufacturers and end users of designated anti-terror and end users of designated anti-terror technologies.technologies.
• All testing data was submitted to DHS for All testing data was submitted to DHS for review and approval.review and approval.
This is currently the ONLY DHS Designated and Certified on-line water anti-terror technology protecting you from
system disruption and potential litigation
180
Dual Use CapabilitiesDual Use Capabilities
• The security aspects of the system The security aspects of the system derive from the event detection software derive from the event detection software and the agent library compiled by Hach.and the agent library compiled by Hach.
• The everyday utility derives from the The everyday utility derives from the event detection software and the plant event detection software and the plant library that is learned on site.library that is learned on site.
181
Plant LibraryPlant Library
• The learning ability and plant library can The learning ability and plant library can be used to correlate problems to be used to correlate problems to changes in water quality.changes in water quality.
• System can be programmed to alert System can be programmed to alert operators when such changes recur so operators when such changes recur so that corrective action can be taken and that corrective action can be taken and the water supply is not compromised.the water supply is not compromised.
182
How the Algorithm Works
BaselineEstimator
GainMatrix A
DistanceMeasure
Unit VectorFormation using Y(t)
VectorSearch
X(t)
Five Parameter Signal Vector Baseline
Deviation Y(t)
+-
Resultant Vector
Report Best Match
Vector Libraries( Agent, Plant )
A two-step process is used: Trigger when deviations indicate agentClassify agent in response to Trigger
Is Threshold exceeded?
No
Yes
Trigger Signal
Threshold Level
Trigger
183
Plant Chlorine Upsets
00.5
11.5
22.5
0 500 1000 1500 2000 2500 3000
Minutes
PP
M C
hlor
ine
Plant Event DefinedPlant Event DefinedName: Pump Shut Off, Type: Name: Pump Shut Off, Type: NORMALNORMAL
184
Trigger Signal - Caustic Feed Event
0
1
2
3
4
0 2 4 6 8 10
Hours
Trig.
Thres .
The plant uses caustic feed to control water pH and experienced an operational problem that resulted in the feed of excess caustic. That affected the pH and the conductivity of the water, causing the Event Monitor to alarm.The Event Monitor learned this Plant Event and can identify a recurrence of the event.
185
Road work near a distribution line dislodged biomass and other particulate matter from the lining of the pipe. There was a massive increase in turbidity, which not only showed up on the turbidimeter, but also showed up as an interference in the chlorine measurement ( optical ). As expected, the conductivity and pH also showed minor changes. The increase in biomass in the water was indicated by the TOC analyzer. This event illustrates the ability of the Event Monitor to detect and alarm on unanticipated events. This event also provides a signature for the materials adhering to the walls of the pipes in this location.
Trigger Signal - Road Work Event
0
10
20
30
40
0 10 20 30 40
Time
Trig.
Thres .
186
Trigger Signal - Pressure Event
0
1
2
3
4
0 5 10 15 20
Hours
Trig.
Thres .
The Event Monitor is located in a building which experiences a daily variation in water pressure. The sample variation is associated with a turbidity increase that causes a Trigger. There is also a small pH decrease at that time, possible because of increased solubility of CO2 in the water, dropping the pH slightly. This pattern is recognized by the Event Monitor as a "Normal" event, rather than an alarm condition.
187
Effects of Variable DemandEffects of Variable DemandDaily events influencing turbidity, chlorine, pH and possibly conductivity are not completely Daily events influencing turbidity, chlorine, pH and possibly conductivity are not completely
understood but suspected to be caused by water demand fluctuations in the area.understood but suspected to be caused by water demand fluctuations in the area. May indicate need for flushing and chlorine booster. May indicate need for flushing and chlorine booster.
Turbidity, Cl2, pH, TOC, Conductivity, Pressure
0
0.5
1
1.5
2
2.5
3
3/15/20060:00
3/16/20060:00
3/17/20060:00
3/18/20060:00
3/19/20060:00
3/20/20060:00
3/21/20060:00
3/22/20060:00
Time
Tu
rbid
ity
, C
l2, p
H, T
OC
-20
-10
0
10
20
30
40
50
60
70
80
Co
nd
ucti
vit
y, P
SI
Turbidity
Chlorine
pH
Conductivity
PSI
188
Ammonia Overfeed EventAmmonia Overfeed Event
• On March 26On March 26thth, 2007, maintenance was performed at the , 2007, maintenance was performed at the Plant. After maintenance was completed, the plant was Plant. After maintenance was completed, the plant was restarted and the system that feeds the ammonia overfed the restarted and the system that feeds the ammonia overfed the chemical. The operator noticed an increase in pH and chemical. The operator noticed an increase in pH and contacted operations at 16:25. Operations reported a contacted operations at 16:25. Operations reported a problem with the ammonia feed pumps. The problem was problem with the ammonia feed pumps. The problem was temporarily fixed but a slug of ammonia was sent into the temporarily fixed but a slug of ammonia was sent into the distribution system. Several customers called, complaining distribution system. Several customers called, complaining about an ammonia smell and taste coming from the tap. The about an ammonia smell and taste coming from the tap. The exact amount of ammonia released was unknown, but was exact amount of ammonia released was unknown, but was believed to be less than 10 ppm. The facility continued believed to be less than 10 ppm. The facility continued operation but temporarily utilizing free chlorine as a operation but temporarily utilizing free chlorine as a disinfectant until July 2disinfectant until July 2ndnd..
189
Ammonia Event
Ammonia Event. Scott Powers noticed the pH spike
and contacted operations at 16:25
0
10
20
30
40
50
60
70
80
3/25/0719:12
3/26/07 0:00 3/26/07 4:48 3/26/07 9:36 3/26/0714:24
3/26/0719:12
3/27/07 0:00 3/27/07 4:48
Time
0
100
200
300
400
500
600
µS
/cm
Trigger
Turbidity
Chlorine
pH
TOC
Temperature
PSI
Conductivity
190
Possible Chlorine Feed EventPossible Chlorine Feed EventOn April 3, 2007 there was a turbidity and pH increase and a decrease in chlorine and On April 3, 2007 there was a turbidity and pH increase and a decrease in chlorine and conductivity. Operator believes that there might have been a problem with the chlorine conductivity. Operator believes that there might have been a problem with the chlorine
feed at the plant. However, this cannot be confirmed. The plant was using free chlorine feed at the plant. However, this cannot be confirmed. The plant was using free chlorine instead of chloramines at the time which rules out the ammonia feed problem.instead of chloramines at the time which rules out the ammonia feed problem.
0
5
10
15
20
25
4/2/0721:36
4/3/070:00
4/3/072:24
4/3/074:48
4/3/077:12
4/3/079:36
4/3/0712:00
Time
200
210
220
230
240
250
260
270
280
290
300
Co
nd
uc
tiv
ity
TriggerTurbidityChlorinepHTOCTemperaturePSIConductivity
191
Air Bubble EventAir Bubble Event
• In one Northern Midwest system, every Friday, the sensors In one Northern Midwest system, every Friday, the sensors would behave extremely erratically resulting in multiple would behave extremely erratically resulting in multiple alarm signals being generated. Investigations led to the alarm signals being generated. Investigations led to the discovery of extreme amounts of entrained air bubbles being discovery of extreme amounts of entrained air bubbles being present in the systems water on Friday afternoons and present in the systems water on Friday afternoons and evenings. evenings.
• Further investigation revealed that school buildings that Further investigation revealed that school buildings that were to be vacant over the weekend had a policy of using air were to be vacant over the weekend had a policy of using air to blow out their water lines to prevent freezing so that the to blow out their water lines to prevent freezing so that the heat could be turned off over the weekend. A faulty check heat could be turned off over the weekend. A faulty check valve at one of the schools allowed the air to bleed into the valve at one of the schools allowed the air to bleed into the distribution system. The valve was replaced, thus closing a distribution system. The valve was replaced, thus closing a possible backflow route into the system. After this the possible backflow route into the system. After this the erratic readings ceased.erratic readings ceased.
192
Main Break #1Main Break #1The break occurred on July 30The break occurred on July 30thth, 2006. The line was a 36” water main located 1.0 , 2006. The line was a 36” water main located 1.0
miles from the WDMP. Conductivity, turbidity, and chlorine spiked. There appears to miles from the WDMP. Conductivity, turbidity, and chlorine spiked. There appears to be two water flow interruptions to the WDMP the night before but it’s unclear if they be two water flow interruptions to the WDMP the night before but it’s unclear if they
are related to the break on the 30are related to the break on the 30thth..
Break
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
7/27/0612:00
7/28/060:00
7/28/0612:00
7/29/060:00
7/29/0612:00
7/30/060:00
7/30/0612:00
7/31/060:00
7/31/0612:00
8/1/060:00
8/1/0612:00
Time
Cl2
, p
H,
TO
C,
Tu
rbid
ity
250.00
255.00
260.00
265.00
270.00
275.00
280.00
285.00
290.00
295.00
Co
nd
uc
tiv
ity
(u
S/c
m)
Cl2
pH
TOC
TURB
COND
193
Main Break #2Main Break #2The break occurred at night on September 20The break occurred at night on September 20thth, 2006. The exact time of the break is , 2006. The exact time of the break is currently unknown, although there appears to be a flow interruption to the WDMP the currently unknown, although there appears to be a flow interruption to the WDMP the
previous morning. The line involved was a 12” water main which is 0.4 miles from previous morning. The line involved was a 12” water main which is 0.4 miles from the WDMP. the WDMP.
September 20th Break, 12" Main, 0.4 Miles From Sensors, Time Unknown
0.00
5.00
10.00
15.00
20.00
25.00
30.00
9/18/06 0:00
9/18/06
12:00
9/19/06 0:00
9/19/06
12:00
9/20/06 0:00
9/20/06
12:00
9/21/06 0:00
9/21/06
12:00
9/22/06 0:00
9/22/06
12:00
9/23/06 0:00
9/23/06
12:00Time
Cl2
, p
H,
TO
C,
Tu
rbid
ity
250.00
255.00
260.00
265.00
270.00
275.00
280.00
285.00
290.00
Co
nd
uc
tiv
ity
(u
S/c
m)
Cl2
pH
TOC
TURB
COND
194
Main Break Event #3August 17 at 10:30 AM
Pittsburgh, PA
0
2
4
6
8
10
12
14
16
18
18:0
0
17:1
0
16:2
0
15:3
0
14:4
0
13:5
0
13:0
0
12:1
0
11:2
0
10:3
0
9:4
0
8:5
0
8:0
0
7:1
0
Time
0
100
200
300
400
500
600
Trigger Turbidity Chlorine pH Temperature Conductivity TOC PSI
195
TurbidityTurbidity
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00
18.00
12
:00
AM
1:2
0 A
M
2:4
0 A
M
4:0
0 A
M
5:2
0 A
M
6:4
0 A
M
8:0
0 A
M
9:2
0 A
M
10
:40
AM
12
:00
PM
1:2
0 P
M
2:4
0 P
M
4:0
0 P
M
5:2
0 P
M
6:4
0 P
M
8:0
0 P
M
9:2
0 P
M
10
:40
PM
Turbidity
196
ChlorineChlorine
0
0.5
1
1.5
2
2.5
0:0
0
1:1
7
2:3
4
3:5
1
5:0
8
6:2
5
7:4
2
8:5
9
10
:16
11
:33
12
:50
14
:07
15
:24
16
:41
17
:58
19
:15
20
:32
21
:49
23
:06
Chlorine
197
ConductivityConductivity
465
470
475
480
485
490
7:0
0
7:2
0
7:4
0
8:0
0
8:2
0
8:4
0
9:0
0
9:2
0
9:4
0
10
:00
10
:20
10
:40
11
:00
11
:20
11
:40
12
:00
12
:20
12
:40
13
:00
13
:20
13
:40
14
:00
14
:20
14
:40
15
:00
15
:20
15
:40
16
:00
16
:20
16
:40
17
:00
17
:20
17
:40
18
:00
Conductivity
198
ConductivityConductivity
Conductivity
400420440460480500520540560
8/8/2005 0:00
8/10/2005 0:00
8/12/2005 0:00
8/14/2005 0:00
8/16/2005 0:00
8/18/2005 0:00
8/20/2005 0:00
8/22/2005 0:00
8/24/2005 0:00
8/26/2005 0:00
Main BreakMain Break48 Hours48 Hours
BeforeBefore
199
36 Inch Main Break
• A geyser caused by a severed 36-inch water line erupts 10:30 a.m., August 17th. One of the largest water main breaks in the city's modern history.
200
A driver who was able to rescue a vehicle follows a man on foot out of a flooded parking garage, following a water main break
201
More than 20 million gallons of water poured out and into nearby parking garages and other low-lying areas Downtown.
202
Workers move a section of new pipe into position as the broken 36-inch water main can be seen in the background.
203
DistributionDistribution
Distribution monitoring can be an effective Distribution monitoring can be an effective means for protecting your customers means for protecting your customers from not only a security threat, but also from not only a security threat, but also from a plant or distribution system upset.from a plant or distribution system upset.
204
Questions?Questions?
205
Process InstrumentsProcess InstrumentsHands-On/DemoHands-On/Demo
• Variety of instruments set up on an Variety of instruments set up on an isolated city water supplyisolated city water supply
• ““Challenge” the instruments withChallenge” the instruments with• CausticCaustic
• AcidAcid
• ChlorineChlorine
• TurbidityTurbidity
206
Summary and ConclusionsSummary and Conclusions
207
Summary and ConclusionsSummary and Conclusions
• Representative sample taps are a critical Representative sample taps are a critical component of any testing protocolcomponent of any testing protocol
• Knowledge and understanding of your Knowledge and understanding of your process is key to running it properlyprocess is key to running it properly
• Data collection is only good if you Data collection is only good if you analyze itanalyze it
• From source to tap, on-line analysis is From source to tap, on-line analysis is essential for safe, secure and high essential for safe, secure and high quality waterquality water
208
Summary and ConclusionsSummary and Conclusions
• Lab instruments are essential for Lab instruments are essential for reporting and verification of process reporting and verification of process instrumentsinstruments
• On-line instrumentation is the most On-line instrumentation is the most effective way to keep your process in effective way to keep your process in controlcontrol
• Significant cost/energy savings can be Significant cost/energy savings can be achieved using on-line instrumentationachieved using on-line instrumentation
209
Questions?Questions?
210
AcknowledgementsAcknowledgements
• Terry Engelhardt, Hach CompanyTerry Engelhardt, Hach Company
• Mike Sadar, Hach CompanyMike Sadar, Hach Company
• Chuck Scholpp, Hach CompanyChuck Scholpp, Hach Company
• Carl Byron, ChemtracCarl Byron, Chemtrac
• Trina Picardi, Hach CompanyTrina Picardi, Hach Company