Fundamental Pool Water Chemistry Chapter 5 8 6/27/2011 Disinfection: (book definition on page 49)

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CHAPTER 5: THE CHEMISTRY OF CHLORINATION WATER CHEMISTRY: DISINFECTION CHAPTER 6: TYPE OF CHLORINE CHAPTER 7: PROTECTING CHLORINE FROM SUNLIGHT CHAPTER 8: CHLORINE GENERATORS, BROMINE, AND

vs. Shocking Elemental Inorganic Organic Chapter 7 Protecting Chlorine from Sunlight, Bromine and Ozone 2011 2 Disinfection: (book definition on page 49) Killing pathogenic

1 CHAPTER 5: THE CHEMISTRY OF CHLORINATION WATER CHEMISTRY: DISINFECTION CHAPTER 6: TYPE OF CHLORINE CHAPTER 7: PROTECTING CHLORINE FROM SUNLIGHT CHAPTER 8: CHLORINE GENERATORS, BROMINE, AND OZONE POOL WATER CHEMISRY Chapters 5 thru 8 Disinfection Pages Chlorine Disinfection Oxidation Residual How it works: HOCl and OCl ph effect on HOCl and OCl Super Chlorination vs. Shocking Elemental Inorganic Organic Chapter 7 Protecting Chlorine from Sunlight, Bromine and Ozone Disinfection: (book definition on page 49) Killing pathogenic (disease-causing) organisms, such as bacteria, parasites, viruses and other organisms such as algae, mold, mildew and spores. It just means that we need to KILL the bad bugs in the water

2 Oxidation: The process of changing the chemical structure of contaminants so they are more readily removed from the water The conversion of the contaminants to simple gases so they will off-gas What contaminates? Oxidation The dead bugs --- Man Made Stuff: Sweat Natural Creams Urine Suntan Lotions Saliva Soap Oils Mucous Deodorants All other body fluids Makeup Lipstick And all the other stuff listed on page The Residual After Chlorine kills the bugs (disinfects) After Chlorine oxidizes the contaminates from the water The Chlorine Demand will be met And a Chlorine Residual will be left in the water This is what we measure

Disinfect Oxidize Residual Disinfection 15% Oxidation 85% 2011 7 The Chlorine in

hydrochloric acid It s the Hypochlorous acid that is important here: HOCl is the

occurs with the Hypochlorous Acid: HOCl Dissociates into HOCl hydrogen ion H + ion

3 Disinfect Oxidize Residual Disinfection 15% Oxidation 85% The Chlorine in Water Reactions Cl 2 H 2 O HOCl HCl Chlorine (gas) + water > hypochlorous acid + hydrochloric acid It s the Hypochlorous acid that is important here: HOCl is the Killing form of Chlorine The Chlorine in Water Reactions A second reaction occurs with the Hypochlorous Acid: HOCl Dissociates into HOCl hydrogen ion H + ion OClẖypochlorite This whole thing is the Free Available Chlorine that we measure

4 The Chlorine in Water Reactions HOCl H + OCl ph % HOCl The chart on page 52 At a ph of 7.5 HOCl is about 55% The Chlorine in Water Reactions HOCl H + OCl - ph % HOCl %OCl Lets Look at the Residual a bit closer (HOCl H + + OCl - ) TAC Total Available Chlorine minus FAC Free Available Chlorine equals CC Combined Chlorine Recommended Chlorine levels on page 56 Chlorine that is combined with ammonia or organic material in the water Chloramines

5 The Best way to rid the Combined Chlorine (Chloramines) Add more chlorine to the pool Equal to 10 times the measured amount of Combined Chlorine For example: If you measured.5 ppm of Combined Chlorine Simply add 5 ppm of Chlorine Elemental Cl 2 Inorganic -- is a Gas We Classify 3 types: Sodium Hypochlorite -- a liquid (Bleach) Calcium Hypochlorite -- a solid Lithium Hypochlorite -- a solid Organic DiChlor -- a solid TriChlor -- a solid Chlorine Gas ( Cl 2 ) Elemental Chlorine An element of nature Number 17 Group 17 on The Periodical Chart of the Elements Greenish yellow gas 2.5 time heavier than air Never found uncombined in nature It is dangerous An irritant at only 3ppm in air

Inorganic Chlorine Liquid Chlorine Sodium Hypochlorite ( NaOCl ) One Gallon of 12 % Trade Grade contain 1 pound of Cl 2 It will degrade quickly (days) as the temperature rises (p.

6 Inorganic Chlorine Liquid Chlorine Sodium Hypochlorite ( NaOCl ) One Gallon of 12 % Trade Grade contain 1 pound of Cl 2 It will degrade quickly (days) as the temperature rises (p.66) Must be packaged with a vented cap It will raise the ph acid needs to be added to the pool after using Getting it your eyes will cause permanent damage in 15 seconds Inorganic Chlorine Cal Hypo Calcium Hypochlorite ( Ca[OCl] 2 ) Granules but can be pre dissolved, then added as a liquid (p.66) A Class 3 Oxidizer will catch on fire easily Will raise ph Will raise calcium level for 10ppm Chlorine added, will raise calcium 7ppm Will explode if mixed with TriChlor Calcium Hypochlorite and a bit of Coca Cola

7 Inorganic Chlorine Lithium Hypochlorite ( LiOCl ) White powder or Granules Dissolves very quickly Relatively higher cost Will raise ph Is Non Flammable and dust free Organic Chlorine ( Stabilized Chlorine Chlorine, by definition which contains cyanuric acid ) DiChlor ( NaCl 2 C 3 N 3 O 3 ) White Granules Fast Dissolving ph Neutral Only about 40% chlorine by weight 50% cyanuric acid, 10% sodium Will raise Cyanuric Acid level for 10ppm Chlorine added, will raise CYA 9ppm Organic Chlorine ( Stabilized Chlorine Chlorine, by definition which contains cyanuric acid ) TriChlor ( Cl 3 C 3 N 3 O 3 ) Tablets or Granular Very Slow Dissolving Low ph 2.8 to 3.0 Only about 45% chlorine by weight, 55% Cyanuric Acid Will raise Cyanuric Acid level for 10ppm Chlorine added, will raise CYA 6 ppm Do NOT put them in the skimmer

8 Available Chlorine ph in 1% Solution ph Effect On Water Physical Form Elemental Inorganic Organic Sodium Calcium Lithium Cl 2 Dichlor Trichlor Hypochlorite Hypochlorite Hypochlorite 100 % % 65, 70 or 75% 28 or 35 % 56 or 62 % 90 % Lowers Raises Raises Raises Gas Liquid Granules Tablets Granules No change Granules Available Chlorine Content (ACC) is the relative amount of oxidizing chlorine as compared to chlorine gas as it is released into water Chlorine manufacturers are Required by the EPA to list the ingredients as well as the Available Chlorine Content Lowers Tablets Granules Chlorine Type Amount to Add for 1ppm Increase In a 10,000 Gallon Pool Gas 1.3oz. 1 pound Equivalents Liquid 12% 10.6 fl. oz. 1 gallon TriChlor 1.5 oz. 1.1 pounds About 2 tabs DiChlor 56% 2.38 oz. 1.8 pounds About.5 of 1 lb. DE Scoop Cal Hypo 65% 2.0 oz. 1.5 pounds About.5 of 1 lb. DE Scoop Lithium 35% 3.8 oz. 2.8 pounds So How Much Chlorine to I add? Given: A 20,000 gallon pool Put in 6ppm using Liquid Chlorine 12% Step 1: Write in the PPM increase you want to add to the pool 6 ppm Step 2: Divide the gallons in the pool by 10,000 20,000 / 10,000 = 2 Step 3: Use Table 6 2 on page 91 Find the Chlorine Type Add write in the 1ppm amount 10.6 fl. oz. Step 4: Multiply Box 1 X Box 2 X Box fl. oz. Divide by 128 to convert to gallons / 128 = about 1 gallon

9 Protecting Chlorine from Sunlight Chapter 7 Pages The Sun s Ultra Violet (UV) rays degrades the chlorine in swimming pools But we can protect tthe chlorine by using the Chemical Cyanuric Acid (CYA) It is sold as: Chlorine Stabilizer Pool Water Conditioner Protecting Chlorine from Sunlight Chapter 7 Pages There is a controversy in our industry over Cyanuric Acid (CYA) It centers around two facts: 1. Cyanuric Acid DOES protect chlorine from the Sun But HOW MUCH does it protect and HOW MUCH is needed is the debate. 2. Cyanuric Acid DOES slow down the kill time of Free Chlorine But HOW MUCH does it slow the kill time of Free Chlorine is the debate Protecting Chlorine from Sunlight Chapter 7 Pages Fortunately we do have a few guidelines You should only use about 10 times (ppm) of CYA For every 1 ppm of Free Chlorine you want to protect The APSP Recommendations: Minimum Ideal Maximum Cyanuric Acid 10 ppm ppm 100 ppm

10 Protecting Chlorine from Sunlight Chapter 7 Pages CYA is good but only when used within the Recommended Guidelines Without CYA the intense summer time sunlight will degrade chlorine 90 95% 95% in just 2 hours CYA will hold the Free Chlorine in the water 6 to 10 times longer (p95) or 4 to 8 times longer (p96) depending on what you read Protecting Chlorine from Sunlight Chapter 7 Pages Adding more CYA than the recommended Guidelines will NOT protect it any more from the sun Its just a waste of money AND It will continue to slow down the kill time of Chlorine CYA will not LOCK UP chlorine (that s a myth) Protecting Chlorine from Sunlight Chapter 7 Pages A couple of other notes about Cyanuric Acid You can always add more But the only practical way to lower it is by Diluting or Drain/Refill Bromine is NOT protected by Cyanuric Acid

Protecting Chlorine from Sunlight Chapter 7 Pages 95 104 Cyanuric Acid C 3 N 3 O 3 Cyanuric Acid C 3 N 3 O 3 Cl 3 With 3 chlorines Attached to

Three things are produced: 1. Hydrogen gas ( H 2 ) at the negative electrode 2. Sodium hydroxide ( caustic soda ) at the positive electrode 3.

11 Protecting Chlorine from Sunlight Chapter 7 Pages Cyanuric Acid C 3 N 3 O 3 Cyanuric Acid C 3 N 3 O 3 Cl 3 With 3 chlorines Attached to the Nitrogen is TriChlor Chlorine can be produced by passing a electrical current through water that has salt in it. Three things are produced: 1. Hydrogen gas ( H 2 ) at the negative electrode 2. Sodium hydroxide ( caustic soda ) at the positive electrode 3. Chlorine gas ( Cl 2 ) also at the positive electrode There are two types of : 1. In Line salt directly in the pool 2. Brine salt in a separate tank

12 Chlorine Generation the In line system Add the salt ( adding Cl ) 2. Pass the salt water ( Cl ) through an electrical current This changes Cl to Cl 2 3. Cl 2 dissolves to make HOCl HOCl disinfects and oxidizes Reducing it to Cl Chlorine Generation the Brine System With the brine system this re cycling does not happen There are two cambers in the tank: a positive charged camber the anode and a negative charged camber the cathode Cl 2 ( Chlorine Gas ) is produced in the anode (Positive) camber. Chlorine Gas is then injected into the water With the brine system you must replenish the salt in the anode camber Chlorine Generation Most residential chlorine generators produce about 1 pound of Cl 2 (pure chlorine) per 24 hours How much salt is needed? Most systems require about 3000 to 3500ppm One pound of salt in a 10,000 gallon pool is about 12ppm

13 Bromine Bromine is an Element just like Chlorine But it s a liquid not a gas It s in the Periodic Table Number 35 In the Halogen Group (Group 17) Bromine Br 2 H 2 O HOBr HBr Bromine + water > hypobromous acid + hydrobromic acid It s the Hypobromous acid that is important here: HOBr is the Killing form of Bromine Bromine The Elemental Liquid is not used in swimming pools Two types of bromine compounds are used: 1. Two part bromine 2. Bromine Tablets

14 Bromine Like Chlorine once it has done its job it is reduced to negative ions Br But unlike Chlorine Bromine can be recycled or reactivated by adding an oxidizer: Chlorine or Potassium Monopersulphate Bromine HOBr H + OBr - The chart on page 177 At a ph of 7.5 HOBr is about 94% ph % HOBr %OBr Bromine Like Chlorine Is destroyed/degraded by the sun s UV rays It will degrade at a lesser rate than Chlorine: About 65% in 2 hours. (Chlorine degrades about 90 95% in 2 hours) Unlike Chlorine Bromine is not protected from the sun with Cyanuric Acid

15 Ozone (O 3 ) It is a Gas It is a great Disinfectant and Oxidizer It is 25 times faster at killing than Chlorine (HOCl) There are two methods of making Ozone: 1: UV 2: Corona Discharge Ozone (O 3 ) Ozone must be dissolved in the water to work It is usually injected into the return plumbing after all the equipment via a Venturi system Ozone (O 3 ) Even though Ozone is a great disinfectant and oxidizer there is little to no residual Consequently A Chlorine residual must be maintained AND CERTIANLY NO Un dissolved should ever enter the pool

16 Any Questions?

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