Joseph Roccaro Water Quality Engineer Suffolk County Water Authority LI Water Conference Legislative Breakfast March 9, 2018

Transcription

1 Joseph Roccaro Water Quality Engineer Suffolk County Water Authority LI Water Conference Legislative Breakfast March 9, 2018

2 Outline 1,4-dioxane properties 1,4-dioxane treatment AOP s Review SCWA work pilot and full-scale Full-scale costs

3 Contaminant Characteristics Selected GW Contaminants Contaminant Freundlich Henry's Log K H* K OW tetrachloroethylene trichloroethylene ,2,3-trichloropropane carbon tetrachloride ,2-dichloropropane Cis-1,2-DCE ,2-dichloroethane ,4- Dioxane 1,1-dichloroethane ,4-dioxane dichloromethane

4 Breakthrough in GAC Filter

5 Why AOP? Contaminant Breakthrough in GAC C/C ,000 10,000 15,000 20,000 25,000 30,000 35,000 Bed Volumes 1-4 dioxane 1,1-dichloroethane (1,1-DCA) 1,1,2-trichlorotrifluoroethane (TCTFA) 1,2 dichloroethane (1,2-DCA) 1,1,1-trichloroethane (1,1,1-TCA) cis-1,2-dichloroethene (cis-1,2-dce) 1,1-dichloroethene (1,1-DCE) carbon tetrachloride (CT)

6 Advanced Oxidation Process (AOP) UV light systems: commonly used for DW disinfection UV AOP: UV + oxidant OH highly reactive OH radical formed. Common oxidants: H 2 O 2 ; O 3; Cl 2 Effective for oxidation of many organic contaminants Most common AOP uses: - indirect potable reuse - GW remediation Process transforms, does not remove.

7 AOP Types Light systems UV-H 2 O 2 UV-Chlorine (HOCl / OCl - ) UV-O 3 TiO 2 / hv / O 2 (photocatalytic) Dark systems O 3 -H 2 O 2 H 2 O 2 / Fe (Fenton)

8 Oxidant Potentials Common Oxidants Oxidant Oxidation Potential (ev) OH 2.80 O H 2 O Permanganate 1.67 Hypochlorite 1.49 Chlorine 1.36 O Sharma, 2011

9 Important AOP Terms & Concepts Transmissivity Ability of light to penetrate through water Scavenging OH reacts with many background contaminants NOM, DOC, alkalinity, chloride, sulfate and nitrate. Inhibits destruction of target contaminants

10 Important AOP Terms & Concepts cont d. Quenching Conversion from oxidant OH << % Residual oxidant (H 2 O 2 ; Cl 2 ; O 3 ) persists in AOP Effluent Can get >75% carry-over of H 2 O 2 Full-scale AOP - Quench excess H 2 O 2 with Cl 2 or GAC By-Products Goal for oxidation of organic contaminants: CO 2 + H 2 O + mineral salts Incomplete oxidation can yield intermediate breakdown products

11 SCWA COMMERCIAL BLVD. AOP PILOT STUDY

12 AOP Pilot Description Objective: Evaluate H 2 O 2 -UV AOP for GW treatment SCWA Commercial Blvd PS 1,4-dioxane; 1,1-DCA; 1,1-DCE; TCE Existing GAC Adsorbers: dia. vessels 40K lb. GAC AOP System: Trojan UVPhox 8AL3 8 low-pressure (LP) lamps; 2 kw 135 L (36 Gal.) reactor volume Q = gpm Calgon FloSorb w/ 165# GAC

13 AOP Pilot Description AOP System cont d. Control Panel Adjustable UV Power UV Transmissivity Analyzer 35% H 2 O 2; adjustable dose Pilot Trials Conducted: Varied Flow rate; UV Intensity; Oxidant type/dose Determined contaminant destruction by-product formation estimate of treatment costs

14 % Removal vs. Peroxide Dose gpm Percent Removal % 90.00% 80.00% 70.00% 60.00% 50.00% 40.00% 30.00% 20.00% 10.00% 0.00% H 2 O 2 ppm 100% UV 1,4 Dioxane 80% UV 1,4 Dioxane 60% UV 1,4 Dioxane 100% UV 1,1 DCA 80% UV 1,1 DCA 60% UV 1,1 DCA

15 AOP Full-Scale System Objectives - SCWA: Performance Design / Operational Concerns Process reliability Ability to fit in existing treatment scheme System I & C / SCADA Integration Effect on downstream GAC H 2 O 2 storage / handling issues & requirements Regulatory requirements Actual Cost full-scale; operational system

16 AOP Full-Scale System Design Review Phase SCDHS / NYSDOH Concerns General Design Comments System Reliability Assuring performance On-line analyzers Alarms / interlocks Ability to BTW By-Product Formation Effects on GAC

17 Current Process Flow Diagram Cl 2 Lime GAC Adsorbers VOC s Well Pump Removal of Low-level VOC s Distribution System

18 Proposed Process Flow Diagram H 2 O 2 H 2 O 2 Analyzer GAC Adsorbers H 2 O 2 Analyzer Cl 2 Lime AOP System H 2 O 2 Carryover Well Pump Destruction of 1,4-Dioxane; VOC s Trace VOC s Removal of H 2 O 2 ; Trace VOC s, and AOP by-products Distribution System

19 AOP Construction 150 gpm 1,100 gpm Pilot Study

20 AOP - Accessibility

21 AOP BTW Capacity

22 AOP Construction

23 GAC Modifications

24 GAC Modifications

25 AOP Construction

26 AOP Construction

27 AOP Analytical Methods UV Transmissivity Peroxide Field Methods Not EPA Approved On-Line Analyzers Test Kits - Field Verification

28 Peroxide 50% Peroxide Oxidant Concerns Design SS & contained piping Handling Regulatory Operations

29 Specified AOP Sampling Parameter AOP Inf AOP Eff GAC Eff 1,4 - Dioxane X X X H 2 O 2 X X X VOCs X X X Carboxylic Acids X X X Aldehydes X X X

30 AOP Start-Up Trials SCWA Conducts initial 3 day BTW trials Confirm system operation Determine: Contaminant destruction By-Product formation Completed Summer 2017

31 AOP Lamp Sleeves

32 Start-Up / BTW Matrix Peroxide Dose UV Intensity 0 mg/l 4 mg/l 7 mg/l 10 mg/l Lamp Power 100% Lamp Power 80% Lamp Power 60% Lamp Power 0% 1 2 = By-product sampling included

33 1,4-DIOXANE DESTRUCTION RESULTS FROM BTW MATRIX TRIALS UV Intensity BPL - 100% BPL - 80% BPL = 60% BPL = 0% Peroxide Dose Aug. 8, 2017 revision 0 mg/l 4 mg/l 7 mg/l 10 mg/l Trial 6 Trial 3 Trial 9 1,4-D Inf / Eff = 10.3 / <0.07 1,4-D Inf / Eff = 11.8 / < ,4-D Inf / Eff = 11.2 / <0.07 >2.2 LRV > 2.2 LRV > 2.2 LRV Trial 7 Trial 4 Trial 10 1,4-D Inf / Eff = 1,4-D Inf / Eff = 1,4-D Inf / Eff = 12.2 / / / LRV 2.2 LRV 2.2 LRV Trial 8 Trial 5 Trial 11 1,4-D Inf / Eff = 1,4-D Inf / Eff = 1,4-D Inf / Eff = 10.7 / / / LRV 1.6 LRV 1.4 LRV Trial 1 Trial 2 1,4-D Inf / Eff = 1,4-D Inf / Eff = 10.7 / / LRV 0.0 LRV Trial # 1,4-D Inf / Eff LRV

34 UV Intensity BPL - 100% BPL - 80% BPL = 60% BPL = 0% Aldehyde RESULTS FROM BTW MATRIX TRIALS Aug. 8, 2017 revision Peroxide Dose 0 mg/l 4 mg/l 7 mg/l 10 mg/l Trial 6 Trial 3 Trial 9 HOP: 0 / 0 HOP: 0 / 0 HOP: 0 / 0 AOP Eff: 2.7 / 4.8 AOP Eff: 0 / 7.9 AOP Eff: 0 / 12.0 GAC Eff: 0 / 0 GAC Eff: 0 / 0 GAC Eff: 0 / 0 Trial 7 Trial 4 Trial 10 HOP: 0 / 0 AOP Eff: 2.8 / 7.9 GAC Eff: 0 / 0 Trial 8 Trial 5 Trial 11 HOP: 0 / 0 AOP Eff: 3.0 / 8.5 GAC Eff: 0 / 0 Trial 1 Trial 2 HOP: 0 / 0 AOP Eff: 0 / 0 GAC Eff: 0 / 0 NOTES: 1. Table shows formaldehyde concentrations in ppb, noted as: Trial # AOP Inf - w/ bovine catalyse; w/o bovine AOP Eff - w/ bovine catalyse; w/o bovine GAC Eff - w/ bovine catalyse; w/o bovine

35 UV Intensity BPL - 100% BPL - 80% BPL = 60% BPL = 0% Carboxylic Acid RESULTS FROM BTW MATRIX TRIALS Aug. 8, 2017 revision Peroxide Dose 0 mg/l 4 mg/l 7 mg/l 10 mg/l Trial 6 Trial 3 Trial 9 HOP: 12.5 / 10.4 / < HOP: 15.6 / < / < HOP: 7.8 / < / < AOP Eff: 15.1 / 10.7 / 6.6 AOP Eff: 18.8 / 13.7 / 7.7 AOP Eff: 16.1 / 13.1 / 7.7 GAC Eff: 12.6 / < / < GAC Eff: < / < / < GAC Eff: < / < / < Trial 7 Trial 4 Trial 10 HOP: 11.1 / < / < AOP Eff: 29.5 / 20.8 / 6.3 GAC Eff: 14.5 / < / < Trial 8 Trial 5 Trial 11 HOP: 5.3 / < / < AOP Eff: 17.1 / 10.9 / < GAC Eff: 5.9 / < / < Trial 1 Trial 2 HOP: 15.5 / 10.3 / < AOP Eff: 12.0 / < / < GAC Eff: 11.7 / < / < NOTES: 1. Table shows organic acid concentrations in ppb, noted as: Trial # AOP Inf - Acetate / Formate / Oxalate AOP Eff - Acetate / Formate / Oxalate GAC Eff - Acetate / Formate / Oxalate

36 AOP Costs Overview of cost model Predicted costs w/ various target value scenarios Capital O&M (fixed and variable) Power, peroxide, parts and maintenance, carbon changeouts, sampling (lab), in-house labor

37 Capital Costs for Commercial Blvd Full-Scale AOP Project Construction of project (AOP, piping, electrical, etc): $910,000 Initial Laboratory Sampling costs (non-recurring): $28,564 Total: $938,564

38 1,4-dioxane occurrence Detected in approx. 40% of all SCWA wells.35 ppb - 94 wells. ppb 28 wells 3.5 ppb 5 wells

39 SCWA COSTS SYSTEM-WIDE BASED ON A GIVEN PROPOSED 1,4 DIOXANE TARGET LEVEL Proposed target value (in ug/l) : 0 System-wide Capital Costs: $ 458,506, System-wide Fixed Annual O&M Costs: $ 24,305, *System-wide Annual Variable O&M costs: $ 11,877, Total Expected Annual O&M costs: $ 36,182, *(Annual variable costs are based on actual 2016 pumpage)

40 SCWA COSTS SYSTEM-WIDE BASED ON A GIVEN PROPOSED 1,4 DIOXANE TARGET VALUE Proposed target value (in ug/l) : 0.35 System-wide Capital Costs: $ 154,844, System-wide Fixed Annual O&M Costs: $ 9,702, *System-wide Annual Variable O&M costs: $ 4,394, Total Expected Annual O&M costs: $ 14,097, *(Annual variable costs are based on actual 2016 pumpage)

41 SCWA COSTS SYSTEM-WIDE BASED ON A GIVEN PROPOSED 1,4 DIOXANE TARGET VALUE Proposed target value (in ug/l) : 1 System-wide Capital Costs: $ 40,295, System-wide Fixed Annual O&M Costs: $ 2,978, *System-wide Annual Variable O&M costs: $ 1,210, Total Expected Annual O&M costs: $ 4,188, *(Annual variable costs are based on actual 2016 pumpage)

42 SCWA COSTS SYSTEM-WIDE BASED ON A GIVEN PROPOSED 1,4 DIOXANE TARGET VALUE Proposed target value (in ug/l) : 3.5 System-wide Capital Costs: $ 6,854, System-wide Fixed Annual O&M Costs: $ 384, *System-wide Annual Variable O&M costs: $ 139, Total Expected Annual O&M costs: $ 523, *(Annual variable costs are based on actual 2016 pumpage)

43 SCWA System-wide Costs Based on 1,4 Dioxane Target Value $1,000,000,000 $800,000,000 $600,000,000 $400,000,000 $200,000,000 $ ,4 Dioxane Target Value Total O&M costs over 20-year period Annual O&M Costs (O&M costs over 20 year period assumes 3% per year cost increase) Annual O&M Costs Capital Costs Total O&M costs over 20-year period

44 Questions?