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 2013 NYC Watershed/Tifft Science and Technical Symposium PA Effective Use of Filter Pilot Testing and Chlorine Dioxide Demonstration Testing to Optimize.

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Presentation on theme: " 2013 NYC Watershed/Tifft Science and Technical Symposium PA Effective Use of Filter Pilot Testing and Chlorine Dioxide Demonstration Testing to Optimize."— Presentation transcript:

1  2013 NYC Watershed/Tifft Science and Technical Symposium PA Effective Use of Filter Pilot Testing and Chlorine Dioxide Demonstration Testing to Optimize Treatment Plant Performance John Civardi, PE – Hatch Mott MacDonald September 19, 2013

2  2013 NYC Watershed/Tifft Science and Technical Symposium PA Outline  Background of Aqua Shenango Water Treatment Plant  Operational Issues and Treatability Study  UV Peroxide at Shenango  DAF Pilot Testing  Filter Testing Phases 1, 2, and 3  Chlorine Dioxide Testing, bench and demonstration  Where We Are Now

3  2013 NYC Watershed/Tifft Science and Technical Symposium PA Plant Background Capacity 16 MGD Raw water from the Shenango River in Sharon, PA. Treatment: ballasted flocculation and dual media filtration, chlorine for primary disinfection and chloramines for secondary disinfection Plant commissioned in early 2000.

4  2013 NYC Watershed/Tifft Science and Technical Symposium PA Plant Schematic Pilot Area Shenango River Raw Water Pump Filters KMnO4 Clearwell ACTIFLO Chlorine Alum Lime Soda Ash PAC Chlorine Caustic Soda Filter Aid Polymer Chlorine Corrosion Inhibitor PAC Ammonia To Distribution Caustic SodaSoda Ash Fluoride

5  2013 NYC Watershed/Tifft Science and Technical Symposium PA Plant Operational Issues  Disinfection By-Products Range HAAs ( ppb) Range TTHMs ( ppb)  UFRVs< 10,000 gal/sf, – Short Filter Runs  Algae  T&O Geosmin and MIB at 160 ng/L  Manganese

6  2013 NYC Watershed/Tifft Science and Technical Symposium PA Water Quality Raw & Treated (Average Conditions) Turbidity (NTU) TOC (mg/l) Algae (Counts/ml) Manganese (ppm) Raw Filter Influent Treated ND Shown Data collected from Pilot Study from 9/15/11 to 1/23/2012 Water Quality/Performance Issues (Maximum Conditions) Turbidity (NTU) TOC (mg/l) Algae (Counts/ml) Manganese (ppm) Raw Filter Influent Treated

7  2013 NYC Watershed/Tifft Science and Technical Symposium PA Treatability Study Options Matrix River4 MG Pre Sed Basin Replace Filter Media Option 1: PAC KMnO4 UV-H 2 O 2 Clearwell Several variations were also considered Option 2: RiverACTIFLO OzoneReplace Filter Media CLO 2 UV-H 2 O 2 Clearwell Option 3: RiverACTIFLO DAFReplace Filter Media CLO 2 UV-H 2 O 2 Clearwell ACTIFLO

8  2013 NYC Watershed/Tifft Science and Technical Symposium PA Historical T&O Treatment and Problems  Powdered Activated Carbon  Residuals Generation  PAC provided limited removal especially with Actiflo  Competitive effects of alum  Could PAC be optimized and is AOP a suitable option?

9  2013 NYC Watershed/Tifft Science and Technical Symposium PA Bench Testing at Aqua’s Neshaminy WTP  Removal of up to 90% Geosmin & MIB is desired at maximum plant capacity  Aqua and Carbon Supplier performed jar tests with Geosmin to assess : – Potential competitive effects of alum on carbon usage – literature contained limited data – Optimum type of PAC – Optimum dose and detention time

10  2013 NYC Watershed/Tifft Science and Technical Symposium PA PAC Testing Results  Dosing PAC together with alum results in significantly lower MIB removal (28% removal Alum/PAC vs 55% PAC then alum)  Testing found that PAC should be added prior to alum  Minimum PAC detention time is 45 minutes  Min./Max. PAC dosage is 30 mg/L - 60 mg/L

11  2013 NYC Watershed/Tifft Science and Technical Symposium PA Plant Impacts of Testing  45 Minutes of Detention Time at 15 MGD requires at 500,000 gallon pre-carbon contact tank with mixers  30 mg/L dosage results in an additional 3,800 ppd of Dry Solids  This would double the plant solids production and require additional residuals treatment equipment

12  2013 NYC Watershed/Tifft Science and Technical Symposium PA Cost Comparison AOP vs PAC UV – H2O2PAC Capital$2.5 Million$2.2 Million O&M$200,000$310,000 Equivalent Uniform Annual Cost $384,000$475,000

13  2013 NYC Watershed/Tifft Science and Technical Symposium PA A Bit About Carbon Footprint

14  2013 NYC Watershed/Tifft Science and Technical Symposium PA Comparison with PAC  No additional sludge handling is needed whereas the PAC process will generate approx 1.5 tons per day of dry solids (100% increase in solids production)  Ability to provide 1 log and higher removal of MIB and Geosmin  Ability to achieve additional microbial disinfection  Smaller footprint than the PAC option  Produces less than 25% CO 2 compared to UV/Peroxide  Aqua Selected UV-Peroxide

15  2013 NYC Watershed/Tifft Science and Technical Symposium PA

16  2013 NYC Watershed/Tifft Science and Technical Symposium PA UV Process Layout Shenango WTP

17  2013 NYC Watershed/Tifft Science and Technical Symposium PA UV Process Layout Shenango WTP Hydrogen Peroxide UV Reactor Flow Meter Chlorine Cooling Water Return Cooling Water Supply NC

18  2013 NYC Watershed/Tifft Science and Technical Symposium PA

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20  2013 NYC Watershed/Tifft Science and Technical Symposium PA

21  2013 NYC Watershed/Tifft Science and Technical Symposium PA Treatability Study to Optimize Filtration  Technical Experts  Workshops  Selected DAF, Filters, and Chlorine Dioxide – DAF minimizes residuals, low polymer use, algae performance ACTIFLO

22  2013 NYC Watershed/Tifft Science and Technical Symposium PA Recommended Option Schematic Shenango River Raw Water Pump Filters KMnO4 Clearwell ACTIFLO Chlorine Alum Lime Soda Ash PAC Chlorine Caustic Soda Filter Aid Polymer Chlorine Corrosion Inhibitor PAC Ammonia To Distribution Caustic SodaSoda Ash Fluoride Pilot: Dissolved Air Flotation Pilot: Filter Optimization To Waste Integration of DAF into the Plant

23  2013 NYC Watershed/Tifft Science and Technical Symposium PA Pilot Testing  Control/Baseline  Components  Coordination with Regulators  Vendors  Why Pilot Test? – Proof of Design Concept

24  2013 NYC Watershed/Tifft Science and Technical Symposium PA Pilot Testing Continued  The Team – Owner: Aqua, PA Plant Staff and Main Office Water Quality, Engineering, and Laboratory in Bryn Mawr, PA – Engineer: HMM Pilot Engineer (Pittsburgh, PA), Data Review & Coordination (Millburn, NJ) – Vendors: DAF Supplier (IDI), Filter Constructor – PADEP – Protocol Approval  Cost – New Filter Columns, DAF Rental, Power, Chemicals  Data Management  Communication: Weekly Conference Calls

25  2013 NYC Watershed/Tifft Science and Technical Symposium PA Pilot Testing Continued Backwash Controls Filter Columns Online Analyzers

26  2013 NYC Watershed/Tifft Science and Technical Symposium PA Protocol  Three seasons: (1) High Algae (2) Cold Water (3) High Turbidity – Phase 1: Filter Optimization (9/27/ /13/11) – Phase 2: DAF and Filters at Control Steady State (10/20/ /23/11) – Phase 3: Filter Optimization for Ballast Flocculation (12/6/11 – 1/24/2012) – Phase 4: Chlorine Dioxide Addition  Control Column with Same Media as Existing Plant Filters  High Turbidity Modifications with Pre-Sedimentation Tank  Integrated Chlorine Dioxide & Sulfuric Acid

27  2013 NYC Watershed/Tifft Science and Technical Symposium PA Pilot Testing Schematic pH Adjustment Raw Water Coagulant Flocculation Chambers Sample Point Polymer (if needed) Air Compressor & Saturator DAF Tank Clarified Water Sludge Scraper Recycle Pump To Filters To Waste Filter Column 60 Filter Column GAC Filter Column 47 Filter Column 72 To Waste From ACTIFLO Same Configuration as Plant

28  2013 NYC Watershed/Tifft Science and Technical Symposium PA Testing Matrix & Lab Coordination

29  2013 NYC Watershed/Tifft Science and Technical Symposium PA Testing Schedule Optimizing: pH, Acid & CLO 2 Dosage, Flow Rates. Filter Optimization with Chlorinated ACTIFLO Water Chlorine Dioxide Optimize Filter DAF Running at Steady State

30  2013 NYC Watershed/Tifft Science and Technical Symposium PA Phase 1: Optimize Filter using Treated ACTIFLO Water Filter Media Configuration Pilot Filter Column SandMedia Depth (in) Effective Size (mm) Uniformity Coefficient Type Depth (in) Effective Size (mm) Uniformity Coefficient Total Media Depth (in) Anthracite Anthracite Anthracite GAC GAC Column 47 Represents the Configuration of the Plant’s Filter Initial Filter Testing Results

31  2013 NYC Watershed/Tifft Science and Technical Symposium PA  Phase 1 Conclusion: Filter GAC had Lower Run Times than Existing Plant Filter Configuration.  Filter 72 had the Longest Run Times Compared to All Columns  Replace Filter GAC with Filter 72 Configuration Under ACTIFLO Treated Water for Benchmark Comparison to DAF  Continue to Phase NYC Watershed/Tifft Science and Technical Symposium Initial Filter Testing Results

32  2013 NYC Watershed/Tifft Science and Technical Symposium PA DAF & Filter Testing Filter Media Configuration Pilot Filter Column SandAnthracite Depth (in) Effective Size (mm) Uniformity Coefficient Depth (in) Effective Size (mm) Total Media Depth (in) Phase 2: Dissolved Air Flotation Under Steady State Conditions Column 72 is the Optimal Configuration from Phase 1 using ACTIFLO Treated Water Column 47 is the Existing Plant Configuration using DAF Treated Water Column 47 Represents the Configuration of the Plant’s Filter

33  2013 NYC Watershed/Tifft Science and Technical Symposium PA DAF Testing

34  2013 NYC Watershed/Tifft Science and Technical Symposium PA DAF & Filters During High Turbidity Events PA  Raw Water (Primary Axis) & Filter Influent (Secondary Axis) Turbidity Spike

35  2013 NYC Watershed/Tifft Science and Technical Symposium PA DAF & Filters During High Turbidity Events PA  Phase 2: Effluent Turbidity with DAF Treated Water Turbidity Spike Filter 1: 35” Anthracite Filter 2: 48” Anthracite Filter 3: 60” Anthracite Filter 4: 60” Anthracite (ACTIFLO) ACTIFLO

36  2013 NYC Watershed/Tifft Science and Technical Symposium PA DAF & Filters During High Turbidity Events Phase 2: Effluent Turbidity with DAF Treated Water Turbidity Spike ACTIFLO Date

37  2013 NYC Watershed/Tifft Science and Technical Symposium PA Initial Conclusions Filter ACTIFLO Treated WaterDAF Treated Water Comparison DAF/ACTIFLO Phase (No.) Average UFRV (gals/sf) Phase (No.) Average UFRV (gals/sf) UFRV (Ratio) 4714,542211, ,211215, ,670215,  DAF Improved Filter Runs (UFRV)  DAF Could Not Handle High Turbidity Events and the Addition of Pre-sedimentation was not Cost Effective  Next Step – Optimize Filters for ACTIFLO

38  2013 NYC Watershed/Tifft Science and Technical Symposium PA Additional Filter Testing  Phase 3: Filter Optimization with Chlorinated ACTIFLO Treated Water Under Cold Temperature Conditions – Column 47: Existing Plant’s Configuration – Column 60 & 72: Optimal Configurations from Phases 1 & 2 Filter Media Configuration Pilot Filter Column No. SandAnthracite Depth (in) Effective Size (mm) Uniformity Coefficient Depth (in) Effective Size (mm) Uniformity Coefficient Total Media Depth (in) Column 47 Represents the Configuration of the Plant’s Filter

39  2013 NYC Watershed/Tifft Science and Technical Symposium PA Filter Data #1 Phase 3: Turbidity Under Protocol Threshold Date

40  2013 NYC Watershed/Tifft Science and Technical Symposium PA Phase 3: Head-Loss with ACTIFLO Treated Water Backwash Occurs when Head-Loss Reaches 120 Inches Filter Data #2 Filter’s 60 & 72 Have Longer Run Times Compared to Filter 47 (Existing Plant) Date

41  2013 NYC Watershed/Tifft Science and Technical Symposium PA Evaluation of Filter Data & Selection of Media * A “ ” indicates that the evaluation criteria goal was achieved. A “+” indicates that the filter media performed better than the existing plant’s filter media.

42  2013 NYC Watershed/Tifft Science and Technical Symposium PA Evaluation of Filter Data & Selection of Media  Summary of PADEP Requirements: Effective Size, Length/Depth Ratios – Min. 12 in of Media in Effective Size Range No Greater than 0.45 to 0.55 mm – Ratio Depth (in) to Media Effective Size (mm) Greater than 40 – Anthracite Effective Size 0.8 mm to 1.2 mm, Uniformity Coefficient No Greater than 1.7 – Sand at Least 85% Siliceous Material with an Effective Size of 0.45 to 0.55 mm and a Uniformity Coefficient No Greater than 1.65  Cost  Availability of Media

43  2013 NYC Watershed/Tifft Science and Technical Symposium PA Evaluation of Filter Data & Selection of Media  Selection of Filter Media: Column 60 – Improved UFRV by 40%, Meaning Longer Filter Runs – Complies with PADEP Standards – Deeper Anthracite Layer with Larger Effective Size – Additional 2 Inches of Sand for Pathogen Barrier – Achieves Water Quality Similar to Existing Filters Optimal Filter Media Configuration Selected Pilot Filter Column No. SandMedia Dept h (in) Effective Size (mm) Uniformity Coefficient Type Depth (in) Effective Size (mm) Uniformity Coefficient Total Media Depth (in) Anthracite

44  2013 NYC Watershed/Tifft Science and Technical Symposium PA Chlorine Dioxide

45  2013 NYC Watershed/Tifft Science and Technical Symposium PA Benefits of Chlorine Dioxide at the Shenango Plant 1. Oxidation of manganese before flocculation allows the manganese to be removed during the clarification process (ACTIFLO) and allows the chlorine dosage applied to the filter influent to be reduced or eliminated. 2. Reduction of the chlorine dosage at the filter influent results in reductions in DBP formation in the Shenango distribution system. 3. Chloramination can increase biofilm and cause nitrification in the distribution system. Chlorine dioxide normally breaks down to form chlorite ion. Studies have shown that the presence of chlorite ion in finished water results in better control of organisms in the distribution system, especially those which cause nitrification

46  2013 NYC Watershed/Tifft Science and Technical Symposium PA Approach at Shenango  Bench Testing  Pilot Testing with DAF  Demonstration Testing  Procurement

47  2013 NYC Watershed/Tifft Science and Technical Symposium PA Bench testing with ClO2

48  2013 NYC Watershed/Tifft Science and Technical Symposium PA Bench Testing Chlorine Dioxide

49  2013 NYC Watershed/Tifft Science and Technical Symposium PA Bench Testing Ozone

50  2013 NYC Watershed/Tifft Science and Technical Symposium PA How is CLO2 Delivered?  ClO2 is best supplied via On-Site Generation Systems – ClO2 gas is too energetic to package and ship - heat, light, pressure, shock sensitive – Road transport of ClO2 gas or solutions is not allowed – Bulk Shipment of CDG 3000 (0.3%) contains 6 lbs chlorine dioxide  Which are then either oxidized or reduced to obtain chlorine dioxide: – ClO3- chlorate ion – ClO2chlorine dioxide – ClO2-chlorite ion

51  2013 NYC Watershed/Tifft Science and Technical Symposium PA Demonstration Testing The purpose of this full scale test was to evaluate the effectiveness of chlorine dioxide as a pre-oxidant to improve the following: 1. Manganese removal in the ballasted flocculation system. 2. Reduction in filter top chlorine dose while still achieving similar pathogen inactivation. Pre-oxidation with chlorine dioxide was expected to reduce the chlorine demand and allow a reduction in the applied disinfection chlorine dose while still maintaining the same effluent chlorine residual. 3. Reduction in formation of DBPs in the combined filter effluent.

52  2013 NYC Watershed/Tifft Science and Technical Symposium PA Demonstration Test  The CLO2 system delivered 15 to 150 pounds per day (ppd) of chlorine dioxide. At an average plant flowrate of 9.5 MGD and a dose of 1.0 mg/L, approximately 80 ppd of chlorine dioxide was used. At a maximum plant flowrate of 16.0 MGD and a dose of 1.0 mg/L, approximately 135 ppd of chlorine dioxide was used.  The chlorine dioxide system was furnished by Siemens and was a Millennium III™ C-150 Auto two chemical flow-pacing chlorine gas/sodium chlorite chlorine dioxide generator capable of producing up to a maximum of 150 lbs/ day of chlorine dioxide with a 10:1 turn-down and automatic flow-pacing capability. Chlorine gas was supplied using the plant’s existing pre-chlorinator. Sodium chlorite at a strength of 25% was used and was delivered in 250 gallon totes. At the maximum chlorine dioxide usage of 150 ppd, 84 gallons of sodium chlorite was used and 79 pounds of chlorine was used.  As this was a demonstration test treating the entire plant flow, design standards from the Pennsylvania Department of Environmental Protection’s Public Water Supply Manual Section IV.B.2 were followed.

53  2013 NYC Watershed/Tifft Science and Technical Symposium PA Findings

54  2013 NYC Watershed/Tifft Science and Technical Symposium PA Chlorite Levels

55  2013 NYC Watershed/Tifft Science and Technical Symposium PA Summary  UV-Hydrogen Peroxide is feasible and cost effective for Geosmin and MIB reduction  DAF provided significant improvement to UFRV but raw water turbidities above 20 NTU were problematic  Chlorine Dioxide can be purchased and used for 100 gpm pilot studies for feasibility studies  Chlorine Dioxide can be cost effectively tested at plant flowrates on the order of 20 MGD

56  2013 NYC Watershed/Tifft Science and Technical Symposium PA Acknowledgements  Aqua, PA American Water – Pete Kusky, Plant Supervisor – Bill Young, Plant Chemist – Larry Wehr, Process Controls – Marc Lucca, VP of Production – Craig Lutz, Water Quality Specialist – Doug Crawshaw, Production Engineer – Bill McGinty, Manager of Treatment/QC – Jack Walter, Division Manager  Infilco (IDI), Siemens  Hatch Mott MacDonald (HMM) – Josef Argenio, EIT – Mark Tompeck, PE Thank You

57  2013 NYC Watershed/Tifft Science and Technical Symposium PA Phase 1: Head-Loss with ACTIFLO Treated Water Backwash Occurs when Head-Loss Reaches 120 Inches Filter’s 60 & 72 Have the Longest Run Times Existing Plant Filter Date GAC Initial Filter Testing Results

58  2013 NYC Watershed/Tifft Science and Technical Symposium PA  At room temperature, chlorine dioxide (ClO 2 ) is a light sensitive gas denser than air, yellow/greenish in color, highly soluble in water, with a chlorine like odor. Cl OO ClO 2 Molecular Structure Technical Overview

59  2013 NYC Watershed/Tifft Science and Technical Symposium PA Technical Overview Chlorine Dioxide belongs to the family of chemicals known as Oxidizers. CLO2 is also a powerful disinfectant.  Ozone  Hydrogen Peroxide  Chlorine  Chlorine Dioxide Measured by ORP potential

60  2013 NYC Watershed/Tifft Science and Technical Symposium PA Why Chlorine Dioxide?  Cost effective disinfectant for regulatory compliance – declining surface water quality favors CLO2 – pH 2-10 – enhanced CxT’s for crypto and giardia – reduces THM’s, THAA’s and AOX – EPA approved for primary and residual disinfection  Selective oxidant – reduces Mn / Fe, assists on particle count reduction and enhances filter runs – Improves taste and odor, oxidizes / destroys sulfides, certain humics / fluvics / phenols  Superior DBP control: – residuals measurable, well studied – does not oxidize bromide to bromate; no reaction with ammonia – does not chlorinate organics

61  2013 NYC Watershed/Tifft Science and Technical Symposium PA Disinfection with ClO2  Broad spectrum biocide – bacteria, viruses, fungi, algae, mollusks and biofilm – Provides CxT credits effective for Giardia and Cryptosporidium in multiple barrier approach – lower “CxT” values versus Cl2 and chloramines – Synergy with UV (pre or post UV for wastewater and reclaim water)  Effective pH 2 to 10 – does not oxidize bromide to bromate – does not react with ammonia – is often more effective and less costly than permanganate in reducing manganese and iron concentrations  Points of Application – ahead of chlorination or chloramination to reduce THM’s – following UV for residual and enhanced disinfection – ahead of ozone to reduce ozone demand and minimize bromate – compatible with chloramines - controls nitrification

62  2013 NYC Watershed/Tifft Science and Technical Symposium PA Auto Flow-Pacing “Chlorine Free” Chlorine Dioxide Generators (1 to 110 kg/hr) 12% Sodium Hypochlorite 15% Hydrochloric Acid 25% Sodium Chlorite Chlorine in-situ on demand

63  2013 NYC Watershed/Tifft Science and Technical Symposium PA Auto Batch Generator – 3 Chemical

64  2013 NYC Watershed/Tifft Science and Technical Symposium PA THM Formation Naock & Doerr 1978 “No THMs with ClO 2 ”

65  2013 NYC Watershed/Tifft Science and Technical Symposium PA Biofilm Control  CLO2 penetrates and kills biofilm  Does not react with ammonia  Retains disinfection capability with no need to overcome ammonia demand  Shown to reduce planktonic population by 98.72% and biofilm population by 99.88%  Additional benefits due the chlorite ion disinfection by-product: – retards nitrification issues – extends life of chloramines Walker, J.T. and M. Morales Evaluation of Chlorine dioxide For The Control of Biofilms. Jour. Water. Sci. Tech.. 35:11 ( ) McGuire, M.J., N. I Lieu and M. S. Pearthree Using chlorite ion to control nitrification. Jour. AWWA. 91:10 (52-61) Gates, D Chlorine Dioxide Handbook, Water Disinfection Series. Denver,CO: AWWA. Pp

66  2013 NYC Watershed/Tifft Science and Technical Symposium PA Point of Addition  To eliminate prechlorination (thereby reducing DBP formation)  Head of treatment train – Low demand waters  Entry to treatment plant (in combination with coagulation) – High demand waters  Intake (sufficient time to react) – Turbid waters – Will not remove TOC, but improves coagulation & particle counts  After sedimentation (reduced demand)  Before ozonation to reduce demand on ozone and to help reduce bromate formation by ozone


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