Maine Water UtilitiesPortland ME Session 22 Wednesday February 7 2018 Number 1 Thank you Presentation is a Tribute to Small Package Plant in Eastern NY Superintendent who had major concerns ID: 1048143
Download Presentation The PPT/PDF document "Monitoring Basic Parameters Can Optimize..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
1. Monitoring Basic Parameters Can Optimize Package Plant Operation Maine Water Utilities-Portland, MESession 22Wednesday, February 7, 2018
2. Number 1Thank you!
3. Presentation is a Tribute to:Small Package Plant in Eastern NYSuperintendent who had major concerns:What is this system supposed to do?What is it doing now?How is it doing?What does it need?
4. Today’s Backwash PracticesMany package plants use inefficient backwash methods.Backwash too soonBackwash too lateImproper chemistryResulting inIncreased wasteVariable effluent water qualityInefficient operation
5. Wasteful BackwashingAssume 7,000 gal/flush 14,000 gal/bw 2 flushes/backwashTrident TR-420 AIdeally, 28,000 gal/cyclePrematurely, could do double ~56,000 gal/cycleTo minimize waste go to terminal headloss w/o turbidity breakthrough.TIMEHEADLOSS
6. Preferred Backwash PracticesMethods can be improved by monitoring basic parameters to initiate a clarifier flush to initiate a filter backwash Based upon:set time intervals, head-loss across the media, and effluent turbidity.
7. Benefits of Optimized Backwash PracticesThe best results rely upon calibrated instrumentationthat accurately monitors these parametersTurbidityheadlossAt the same time produce high quality effluent, minimize waste and increase net production.save time and money
8. Basic Process ComponentsFiltering ModeTankCLARIFIERMEDIAFILTER MEDIARAWFinishedWashtroughChemistryRaw Water headerUnderdrains
9. Typical Package PlantCleaning stepCLARIFIERMEDIAFILTER MEDIAWashtroughUnderdrainsAir distributionsBackwashWasteRAW
10. Backwashing Filter on TimeTypically this set-time is measured in minutes or hours by the PLC program. Works well when water quality stays consistent or if it is fairly stable, flush, backwash, and downtime; occur while the demand is low.
11. Backwashing on Time-ConcernsNot effective when source water is variable Increases in solids loading and can shorten clarifier and filter run times. Flushing and backwashing based on a set-time can be costly. If too often, more waste is produced and fill the waste storage basins or lagoons to frequently. If too infrequently, excessive solids can spill over onto the filter.Future flushes or backwashes limited as lagoons are too full cleaning the lagoon is lost time and may even prevent the plant from producing usable water
12. Infrequent Flushing/Backwashing ConcernsExcessive solids collect in the clarifier and spill over onto the filter. Headloss increases.Breakthrough occurs when the solids holding capacity of the clarifier media or filter media is exceeded and solids pass through the media. In some cases, excessive headloss developed in clarifiers can damage the equipment and creating unnecessary downtime and expense for repairs. With the filter there is the risk that effluent water quality could be impaired.
13. Package Plant NuancesFast processNeed to keep instrumentation operativeChemistry must respond accordinglyValves and actuators to respond quickly
14. Basic Monitoring ParametersShow how well the process is working and Help optimizing the overall package plantInfluent turbidity settled water turbidity or inter-stage turbidityfiltered effluent water turbidity Headloss across the clarifier and filterParameters recorded either on a log sheet or continuously with a plant SCADA system
15. Clarifier and Filter HeadlossEach includes a snap switch and gauge.Could be a pressure transducer.Clarifier on left includes hi-hi alarm/shut-down
16. Sample data table
17. SuggestionOne manufacturer suggests:For the best characterization of the performance of the clarifier, make turbidity readings on the influent and effluent at least once per hour throughout a run. It is important to do this frequently since, under certain conditions, the removal across the clarifier can change significantly throughout a run.The filter effluent turbidity (if not recorded continuously) should be checked frequently; as often as once every half-hour for an in-depth characterization.
18. Computing Solids RemovalFor example for the Clarifier at hour 3: (7.2- - 0.7) / 7.2 = 0.903 or 90.3% And for the filter (0.7 – 0.06) / 0.7 = 0.914 or 91.4%
19. Ideal OperationBy reviewing the current operation of an existing water treatment plant using the parameters as noted, the best time to flush the clarifier or backwash the filter can be determined based on minimizing breakthrough.
20. BreakthroughRapid headloss build-up due to high solids loadingItems to reviewRaw quality PretreatmentReview process
21. Monitoring Headloss DevelopmentClarifier and Filter Headloss Profile
22. Dual Clarifier Package PlantClarifier EffluentRaw WaterFilter Effluent Clarifier and Filter Turbidity ProfileClarifier Influent
23. How long to flush or backwash?During a flush or backwashOnce process startedTake a grab sample from the waste trough every minuteGo to lab and measure turbidityMake a graph turbidity versus time
24. Lincoln, NH
25. Clifton, TN
26. Waste Washout CurveBe aware solids loading changes with changing influent water quality.Use as a seasonal referenceCan save you waste producedCan improve clarifier and or filter run timeImprovements in clarification and extend filter run time.Basic Parameter measured…… Turbidity!
27. OptimizationConsider adjusting the time between clarifier flushes and filter backwashes. This can be done in most of the PLC programs.In conjunction with the time adjustments, adjust the headloss switches used to initiate the clarifier flush and filter backwash. This can be done by adjusting the switch settings.Review the percent solids removed in both the clarifier and filter that can uncover which process has more room for adjustment.
28. Optimization (continued)Consider modifying the dosage or type of coagulant or polymer being used. Consult with your chemical supplier who can conduct on site jar testing of various options.Consider cleaning or replacing the media. Media analysis can be conducted by the manufacture or media supplier to determine if the media is worn or contaminated.Keep various turbidity and headloss profiles based on seasonal operations to check the impact of changing coagulant or polymer dosages.In all cases, before making any major change to your full scale operations, contact your local regulators or rural water association..
29. Fort Bragg, CAHeath Daniels Lead Treatment Plant Operator – Water of Fort Bragg, CA . Heath adjusted the filter pressure settings and was able to extend his filter run length from 1924 minutes to 2632 minutes. (11.8 hrs)That’s a 37% increase in filter run time for Fort Bragg. For California, especially during drought conditions, this is a major improvement.
30. Baldwin WTP, GA
31. ConclusionsOptimizing operations will save days of potential backwash time and money on an annual basis.Operators must be focused on calibrating the instrumentation, properly operating the equipment, and periodically checking performance to ensure optimized operation. Changing water quality or chemistry can upset the process and system may need to run a performance test. The breakthrough point can be directly associated with clarifier and filter headloss. The goal is to get as close to the breakthrough point as possible without exceeding it.
32. ConclusionsMaximizing solids holding capacity is paramount to understanding the optimal performance of the package plant. Optimizing the process to operate with less frequent clarifier flushing and filter backwashing can reduce waste water production Keeping, and reviewing, results of multiple tests are useful to optimizing the system’s performance on a long term basis. This test is independent of clarifier types, filter media types, underdrains system, or backwashing techniques. Consult with the manufacturer for additional thoughts and suggestions on how to further optimize the process.
33. Food for thought:What do you do for a living?
34. For Additional InformationLocal Contact:David F. Sullivan & Associates, Inc.Phone (603) 474-2484 email: info@davidfsullivan.comBrochureWesTech Engineering, Inc:Matt Williams-RSM -Richard Ross-RPMPhone: 801-803-4912 -Phone: 443-255-5973Email: mwilliams@westech-inc.com -Email: rross@westech-inc.com
35. Monitoring Basic Parameters Can Optimize Package Plant Operation Maine Water Utilities-Portland, MESession 22Wednesday February 7, 2018