A. Yavich, Ph.D., P.E. Optimization Solutions Environmental, LLC Grand Rapids, MI

Transcription

1 A. Yavich, Ph.D., P.E. Optimization Solutions Environmental, LLC Grand Rapids, MI

2 The SMART Approach to Effective Treatment Operation Specific Management And Relationship Tools

3 The Three Pillars Of Effective Treatment Operation Process Management Operational Relationships Decision Tools

4 Process Management Process Management Water utilities need to adopt a concept of managing the entire treatment operation, not only the individual processes.

5 Operational Relationships Operational Relationships Effective process management is only possible if there is a clear understanding of cause-andeffect relationships between unit processes and operations.

6 Decision Tools Decision Tools Water treatment plants need specific process assessment/decision tools to effectively manage plant operation.

7 Operational Perspective of the Flint Case Ferric chloride Polymer anionic and Lime cationic Carbon dioxide Chlorine Chlorine Ozonation Coagulation Flocculation Sedimentation Lime Softening Recarbonation Filtration

8 Corrosion Control Using CaCO 3 Protective Scale Treatment Coagulation Lime-softening Disinfection Effluent Quality ph Alkalinity Ca Corrosion Indices LSI CCPP Formation of CaCO 3 protective scale

9 Raw Water Quality at Flint Parameter Flint WTP Hardness, mg/l as CaCO Alkalinity, mg/l as CaCO noncarb Hardness, mg/l as CaCO Mg 2+, mg/l 5-20 The Flint River water quality was capable of providing corrosion protection in the plant distribution system without additional corrosion control treatment.

10 Coagulation at Flint Parameter Flint WTP TRFP* Source water Flint River St. Joseph River Turbidity, NTU Coagulation Ferric Chloride Ferric Sulfate Avg. coagulant dose, mg/l 53 9 Avg. cationic polymer, mg/l Avg. anionic polymer, mg/l Filter effluent turbidity, NTU * Three Rivers Filtration Plant, Fort Wayne, IN With excessive use of ferric chloride and polymers, coagulation at Flint was extremely ineffective.

11 Effect of Coagulation on Corrosion Control Water Quality Parameters 2FeCl 3 + 3Ca(HCO 3 ) 2 2Fe(OH) 3 + 3CaCl 2 + 6CO 2 alkalinity Alkalinity Lime usage Carbonate Ca Excessive use of ferric chloride had dramatic negative effect on corrosion control conditions in the Flint distribution system.

12 Other Corrosion Control Underlying Problems at Flint Lime-softening process x Split treatment w/excess lime not warranted DBP control/disinfection x x x Increased ferric chloride doses not warranted Activated carbon filters used incorrectly Ozonation used incorrectly

13 Corrosion Protection at Flint Parameter Finished Water Average LSI -0.2 Average CCPP, mg/l -1.5 Ineffective treatment operation at Flint rendered the water to dissolve rather than to form protective calcium carbonate scale in the distribution system.

14 Why Flint Operation Was Ineffective? Process x Management Operations were managed without consideration of how a change in one part of the operational process affected other parts of the process.

15 Why Flint Operation Was Ineffective? Operational x Relationships Lack of understanding of sitespecific relationships between unit processes and operations.

16 Why Flint Operation Was Ineffective? Decision x Tools The plant did not have necessary operational tools to effectively address various operational challenges.

17 Three Rivers Filtration Plant (TRFP) Fort Wayne, IN Plant capacity: 72 MGD Source water: St. Joseph River

18 Raw Turbidity at TRFP

19 Raw Hardness at TRFP

20 Raw UV 254 at TRFP

21 Process Optimization at TRFP TRFP was one of the first U.S. water treatment plants to employ computer models for management and optimization of its treatment processes.

22 Filter Effluent Turbidity

23 Corrosion Control Challenge In 2010, extremely challenging raw water conditions developed: o low alkalinity o high noncarbonate hardness o high magnesium concentrations In the summer/fall of 2010, the plant exceeded action level for lead.

24 Operational Actions Considered x Orthophosphate Chemical feed adjustments

25 Operational Measures Implemented Operational guideline for chemical feed adjustments Corrosion control model Cationic polymer

26 Lead Concentration in Customers Tap

27 Chemical Costs Over the course of the project, TRFP realized a chemical cost saving of nearly $3.5M.

28 Computer Models at TRFP Chemical feed control Process analysis and optimization Operational Guidelines

29 Operational Guideline at TRFP Cause-and-Effect Diagrams Decision-Making Diagrams

30 Cause-and-Effect Diagrams Coagulation

31 Decision-Making Diagrams Filter Effluent Turbidity

32 What is Behind Effective Operation at TRFP? Process Management Any operational change is analyzed for its impact on the entire treatment process. The plant performance is routinely analyzed for potential challenges.

33 What is Behind Effective Operation at TRFP? Operational Relationships Clear understanding of cause-andeffect relationships between unit processes and operations.

34 What is Behind Effective Operation at TRFP? Decision Tools TRFP employs a range of operational tools to effectively manage plant operation and address various operational issues.

35 Summary

36 When facing water quality challenges, WTPs often focus on symptomatic treatment.

37 WTPs often try to mitigate problems without consideration of how a change in one part of the operational process would affect other parts of the process.

38 Effective operation requires identifying and resolving the problems root causes, and not merely mitigating the effects of these problems after they arise.

39 Effective operation also requires understanding of site-specific relationships between unit processes and operations.

40 The SMART approach provides operational tools that enable WTPs to improve the quality of finished water, reduce costs, and successfully resolve operational challenges.

41 Alex Yavich Optimization Solutions Environmental, LLC