Do Cation Exchange Systems Affect the Chlorination Process? Presented By: Jeffrey W. Freeman, P.E., CFM, LEED AP Engineering Enterprises, Inc. March 22, 2016
Presentation Overview Ebony-Ammonia & Ammonium- Ivory Gimme A Breakpoint Holy # of Test Methods Cation Exchange Treatment Exposed
Presentation Overview (Cont.) Evidence More Evidence Take That, Variable Ammonia! Acknowledgements and Q&A
Ebony-Ammonia & Ammonium-Ivory
Ebony-Ammonia & Ammonium-Ivory Ammonia Dissolution In Water pK a = 9.25 + + OH - NH 3 + H 2 O NH 4 Ammonia Ammonium Total Ammonia NH 3 + NH 4 + Free Ammonia NH 3 Only
Ebony-Ammonia & Ammonium-Ivory Ammonia & Ammonium Dissolution pH = 9.25; Temperature = 20 O C 9.25 Source: Manual for Bosanska Krupa Nov. 2009
Ebony-Ammonia & Ammonium-Ivory Ammonia & Ammonium Dissolution pH = 9.25; Temperature = 20 O C 7.5 Source: Manual for Bosanska Krupa Nov. 2009
Ebony-Ammonia & Ammonium-Ivory Chloramine Chemistry Monochloramine Development NH 3 + HOCl NH 2 Cl + H 2 O Dichloramine Development NH 2 Cl + HOCl NHCl 2 + H 2 O Nitrogen Trichloride Development NH 2 Cl + HOCl NCl 3 + H 2 O
Gimme a Breakpoint
Gimme a Breakpoint Breakpoint Chlorination Overview Hump Total Chlorine Residual Breakpoint Chlorine Added
Gimme a Breakpoint Breakpoint Chlorination Overview (Cont.) Monochloramine Monochloramine Dichloramine To Dichloramine Development To N ‐ Trichloride Total Chlorine Residual Total & Free Ammonia Total Total Free Ammonia Chlorine Chlorine Total Chlorine Nitrogen Free Trichloride Ammonia Chlorine Added
Gimme a Breakpoint Breakpoint Chlorination Overview (Cont.) Cl 2 :NH 3 ‐ N<5:1 Cl 2 :NH 3 –N>5:1 Cl 2 :NH 3 –N>7.6 ‐ 9:1 Monochloramine Monochloramine Dichloramine To Dichloramine To N ‐ Trichloride Total Chlorine Residual Total & Free Ammonia Total Total Free Ammonia Chlorine Chlorine Total Chlorine NItrogen Free Trichloride Ammonia Cl 2 :NH 3 –N = 5:1 Cl 2 :NH 3 –N = 7.6 ‐ 9:1 Chlorine Added
Gimme a Breakpoint Five (5) Recommended Parameters To Confirm Breakpoint Has Been Achieved: Free Ammonia Total Ammonia Monochloramine Total Chlorine Free Chlorine
Holy # of Test Methods
Holy # of Test Methods Typical Ammonia Test Methods Nessler Method: No Longer Standard Method Approved Salicylate Method: Recommend For Total Ammonia Indophenol Method: Recommend For Free Ammonia & Monochloramine Ion Selective Electrode: Ideal Method For Precision, But Higher Capital & O&M Costs
Holy # of Test Methods Typical Chlorine Test Methods DPD (N,N Diethyl-1,4 Phenylendediamine Sulfate) Recommended For Total Chlorine and Free Chlorine, If Breakpoint Achievement Has Been Confirmed Used With Many Test Kits/Analyzers Free Chlorine Must Be Read Within a Minute of Sample Preparation Total Chlorine To Be Read Within 3 – 5 Minutes After Sample Prepared Indophenol Recommended For Free Chlorine Confirmation It Is Not An IEPA Approved Method For Free Chlorine Measurement
Holy # of Test Methods DPD Free Chlorine Test Method Additional Comments Chloramines Are Known To Interfere With the Free Chlorine DPD Method The Longer The Sample Sits, the Greater the Amount of Interference Occurs DPD Method Is Accurate When Chloramines Are Not Present Excerpts From Hach DPD Free Chlorine Test Method Instructions
Holy # of Test Methods Indophenol Free Chlorine Test Method Additional Comments It Is Not An IEPA Approved Test Method Chloramines Do Not Interfere With Method It Is a Good Check To Confirm Past Breakpoint Excerpts From Hach Indophenol Free Chlorine Test Method Instructions
Cation Exchange Treatment Exposed
Cation Exchange Treatment Exposed Cation Exchange Treatment Summary General Definition of Ion Exchange Treatment (Source: New Hampshire Department of Environmental Services): Ion exchange (IE) is a water treatment method where one or more undesirable contaminants are removed from water by exchange with another non- objectionable, or less objectionable substance. Both the contaminant and the exchanged substance must be dissolved and have the same type (+,-) of electrical charge. Cation Exchange (CE) Treatment Targets Cations Ions With + Charge Typical Regenerant is Sodium Chloride (NaCl)
Cation Exchange Treatment Exposed Typical Target Cations In NE IL +1 +2 Sodium Hardness Copper 2+ Cations Iron 2+ Zinc 2+ Barium & Radium Lead 2+ Source: http://science notes.org/use ‐ periodic ‐ table/
Cation Exchange Treatment Exposed Affinity ( / əˈ fin ə dē/ ) : [Biochemistry] the degree to which a substance tends to combine with another. (Source: www.google.com) Source: Water Quality & Treatment, AWWA
Cation Exchange Treatment Exposed Ion Exchange General Exchange Process HARDNESS CATIONS Ca 2+ Ca 2+ Ca 2+ Mg 2+ Mg 2+ Mg 2+ Ra 2+ Radium Na + Na + Na + Na + Na + Na + Barium Ba 2+ Na + Na + Na + Na + Schematic Calcium Ca 2+ Na + Cation Na + Exchange Na + Na + Magnesium Mg 2+ Resin Bead Na + Na + + Ammonium Na + NH 4 Na + Na + Na + Na + Na + Na + Sodium Na +
Cation Exchange Treatment Exposed Ion Exchange General Exchange Process RADIUM & BARIUM CATIONS Ra 2+ Ra 2+ Ba 2+ Ba 2+ Ra 2+ Radium Na + Na + Mg 2+ Ca 2+ Barium Ba 2+ Mg 2+ Ca 2+ Schematic Calcium Ca 2+ Cation Mg 2+ Ca 2+ Exchange Resin Bead Magnesium Mg 2+ Na + Na + + Ammonium Na + NH 4 Na + Na + Na + Na + Na + Na + Sodium Na +
Cation Exchange Treatment Exposed Ion Exchange General Exchange Process AMMONIUM CATIONS + NH 4 + NH 4 Ra 2+ Radium Ra 2+ Mg 2+ Ca 2+ Barium Ba 2+ Ba 2+ Ra 2+ Schematic Calcium Ca 2+ Cation Mg 2+ Ca 2+ Exchange Resin Bead Magnesium Mg 2+ Na + Ba 2+ + Ammonium NH 4 Na + Na + Na + Na + Na + Na + Sodium Na +
Cation Exchange Treatment Exposed Ion Exchange General Exchange Process MORE HARDNESS CATIONS Mg 2+ Ca 2+ Ra 2+ Radium Ra 2+ Mg 2+ Ca 2+ Barium Ba 2+ Ba 2+ Ra 2+ Schematic Calcium Ca 2+ Cation Mg 2+ Ca 2+ Exchange Resin Bead Magnesium Mg 2+ + NH 4 Ba 2+ + Ammonium NH 4 Na + Na + NH 4 + Na + Na + Na + Sodium Na +
Cation Exchange Treatment Exposed Ion Exchange General Exchange Process REGENERATION Na + Na + Na + Na + Na + Na + Na + Na + Na + Ra 2+ Radium Ra 2+ Na + Na + Na + Na + Mg 2+ Ca 2+ Na + Na + Na + Na + Barium Ba 2+ Ba 2+ Ra 2+ Na + Na + Na + Na + Schematic Calcium Ca 2+ Cation Mg 2+ Ca 2+ Exchange Resin Bead Magnesium Mg 2+ + NH 4 Ba 2+ + Ammonium NH 4 Na + Mg 2+ Ca 2+ Na + Sodium Na +
Cation Exchange Treatment Exposed Ion Exchange WTP Process Flow Schematic Well Fl PO 4 Cl 2 Flow Control No. 1 Valve Bypass Meter Meter Meter Cation Exchange Water Distribution Meter Units System Well No. 2 Meter Sanitary Sewer NaCl System Backwash Surge Regeneration Tank System
Evidence
Evidence Theory Confirmation No. 1 Village of Montgomery Wells No. 14 & 15 WTP Background Well No. 14 Ironton Galesville DSS Well Raw Water Hardness = 235 mg/l as CaCO 3 Combined Radium = 6.6 pCi/l WTP Contains Five (5) CE Units With Bypass Flouride, Polyphosphate and Chlorine Gas Added After CE Units Treated Water Distributed Directly Into System
Evidence Theory Confirmation No. 1 (Cont.) Sampling & Testing Summary Occurred Every 30 Minutes From 8:00 AM – 2:00 PM on April 3, 2013 Testing Locations Raw Water Post CE/Pre-Chlorination Composite Finished Tested For Five (5) Test Parameters – Free & Total Ammonia, Chloramine, Free & Total Chlorine Note: Chlorine Dose = 1.9 mg/l
Evidence Wells No. 14 & 15 WTP Sample Locations Well Raw Fl PO 4 Cl 2 Finished Flow Control No. 14 Meter Valve Bypass Meter Meter Post CE / Well No. 15 Pre ‐ Chlor (Composite) Meter Cation Exchange Units
Evidence Raw Water Ammonia Levels W ELL N O . 14 AND W ELLS N O . 14 & 15 WTP
Evidence Raw & Post CE / Pre-Chlor Ammonia Levels W ELL N O . 14 AND W ELLS N O . 14 & 15 WTP
Evidence Finished Ammonia & Chloramine Levels W ELL N O . 14 AND W ELLS N O . 14 & 15 WTP Mono To Di Mono To Di Near BP
Evidence Finished Ammonia & Chlorine Levels W ELL N O . 14 AND W ELLS N O . 14 & 15 WTP Mono To Di Mono To Di Past BP
Evidence Raw & Finished Ammonia & Chlorine Levels W ELL N O . 14 AND W ELLS N O . 14 & 15 WTP
Evidence Finished Chlorine Residuals W ELL N O . 14 AND W ELLS N O . 14 & 15 WTP
More Evidence
More Evidence Theory Confirmation No. 2 Village of Montgomery Well No. 8 WTP Background Well No. 8 Ironton Galesville DSS Well Raw Water Hardness = 210 mg/l as CaCO 3 Combined Radium = 11.5 pCi/l WTP Contains Three (3) CE Units With Bypass Flouride, Polyphosphate and Chlorine Gas Added After CE Units Treated Water Distributed Directly Into System
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