1. Ozone Applications By
Ed Knueve
ClearWater Tech, LLC.

2. Topics of Discussion What ozone does not do What ozone does well
Mass transfer basics
Applications:
Commercial well water treatment
Residential wells
Bottling plants
Water stores

3. What Ozone Does Not Do

4. What Ozone Does Not Do
Ozone is incapable of oxidizing radon, methane, and nitrates
Below pH of 9, ozone is incapable of oxidizing ammonia at any practical rate
Ozone can not practically oxidize any of the trihalomethanes except very slowly

5. What Ozone Does Not Do
Ozone can not oxidize chloride ion to produce free chlorine at any practical rate
Ozone cannot oxidize calcium, magnesium, carbonate, or bicarbonate ions; consequently, ozone can not treat hardness or alkalinity

6. What Ozone Does Do Well

7. What Ozone Does Well Disinfection
Ozone kills bacteria, viruses, spores and cysts through a process called cellular lysis - an oxidation process in which ozone ruptures the cellular membrane of the micro-organisms and disperses the cytoplasm into solution.
With bacteria such as E. Coli, streptococcus fecalis, and legionella pneumophila relatively low doses of ozone are required and inactivation occurs up to 3,125 times faster than chlorine.

8. What Ozone Does Well Disinfection:
A 3-log (99.9%) reduction of viruses can be easily achieved with significantly lower CT values than for chlorine.
Spores and cysts such as Giardia and Cryptosporidium can be inactivated with relatively high dosages of ozone. Crypto requires increasingly higher dosages of ozone for inactivation, currently with CT values 5 times that of Giardia. There is no established CT value for Cryptosporidium inactivation with chlorine.

9. What Ozone Does Well Taste and Odor Control Algae Control
Ozone oxidizes the organics such as tannins, unsaturated aldehydes, humic and fulvic acids, etc. responsible for 90% of taste and odor problems.
Algae Control
Ozone effectively kills plankton by oxidizing essential organic compounds that are part of the metabollic process.

10. What Ozone Does Well Oxidation Pre-oxidation
Ozone’s powerful oxidation potential can remove a variety of man-made organic compounds including pesticides, VOCs, SOCs, and other micro pollutants.
Pre-oxidation
Ozone’s powerful oxidation potential can precipitate dissolved iron, manganese, and sulfide faster than any other commonly used oxidants, aiding removal by direct filtration

11. Benefits of Ozone Generated on site More powerful than chlorine
No transportation or storage required.
More powerful than chlorine
100 times the oxidizing power of chlorine without the handling problems
Reverts to oxygen leaving no telltale taste or odor to be removed
Greatly simplifies water chemistry and control.

12. Mass Transfer Basics

13. Mass Transfer Basics
Mass transfer is the movement of molecules of a substance to and across an interface from one phase to another.
i.e.: the amount of ozone that transfers from air, across the air-water interface and into water.

14. Mass Transfer Basics Factors affecting transfer of gas into liquid:
Pressure: as pressure increases, more gas is forced into liquid.
Temperature of the water/gas mixture: at lower temperatures, ozone gas is more easily absorbed into liquid. At higher temperatures, water tries to release gas rather than absorb it.

15. Mass Transfer Basics:
Factors affecting the transfer of gas into liquid:
Bubble size: as a gas is broken down into more and more smaller bubbles, the total surface area of the bubbles increase, thus increasing the surface area for interaction of ozone and water.
Concentration of ozone in the carrier gas: at higher ozone concentration in the carrier gas, higher amounts of ozone are absorbed into the water.

16. Mass Transfer Basics Concentration of ozone in the carrier gas:
Ultra violet ozone generators
- 0.01% to 0.10% concentration by weight (0.10% concentration = 1,000 ppm)
Corona discharge ozone generators
- 1.0% to 6.0% concentration by weight (1.0% concentration = 10,000 ppm)
The concentration of ozone gas is determined at a standard temperature of 68º F (20º C) and standard pressure of 1 atmosphere (14.7 psi).

17. Mass Transfer Basics Concentration of ozone in the carrier gas:
At the same percentage of mass transfer efficiency, a CD ozone generator will deliver more ozone to the water than an UV ozone generator.
Ozone concentration directly affects it’s ability to become soluble in water.

18. Mass Transfer Basics
Concentration of ozone in the carrier gas:

19. Aeration vs. Venturi Injection
Bubble diffusion
Pressure in the system created by water column - relatively low pressures
Taller tanks will increase system pressure.
Large bubble size - smaller total surface area for ozone and water interface to occur
Diffusion devices with smaller pore sizes are more likely to clog.
Mass transfer efficiencies up to 75%, typically around 50%.

20. Aeration vs. Venturi Injection
Differential pressure venturi injector technology utilizes water flow to create a vacuum to pull ozone gas into water.
A turbulent interaction of the ozone gas and water occurs at the throat of the injector as the gas/water stream compresses, expands, and recompresses rapidly creating cavitation.
Very fine bubbles are created allowing more total surface area for ozone and water interface to occur.

21. Aeration vs. Venturi Injection
The back pressure at the outlet of the injector allows higher levels of ozone to dissolve into solution.
Typically requires a 20 psi pressure differential.
When properly sized, up to 99% mass transfer efficiencies can be achieved.
Mazzei venturi sizing?

22. Applications

26. Commercial Water Treatment

27. Commercial Water Treatment
Water source
Well water - generally very good quality; ozone used for pre-oxidation of dissolved metals including iron, manganese, and sulfides into filterable precipitate
Wells with surface water intrusion - generally very good quality; ozone used for pre-oxidation of dissolved metals into filterable precipitate and disinfection, typically coliform bacteria
Surface water - varying water quality; ozone used for primary disinfection, color, taste, and odor removal

28. Commercial Water Treatment
Disinfection
Independent of pH.
Spores and cysts including Giardia, Cryptosporidium, etc. - sizing based on CT values, typically requires high dosages
Currently, the EPA recognizes ozone as the only oxidant capable of Cryptosporidium inactivation - CT values 5 times that of Giardia
Bacteria and viruses including coliform bacteria, E. Coli, Legionella, etc. - applied dosage of 1.5 mg/l recommended

29. Commercial Water Treatment
Disinfection: the C.T. value concept
C = the residual concentration of the disinfectant in mg/L measured at or before the first point of consumption
T = the contact time required (in minutes) for water to travel from the point of injection to the point where C is measured the residual
For example: A 0.4 disinfection residual after a 4 minute contact time (.4 x 4 = 1.6) will yield a CT value of 1.6.

30. CT Values for Giardia Cyst Inactivation by Ozone:
At various water temperatures - pH can be anywhere between 6 and 8 (Source: EPA, SWTR Guidance
Manual,October, 1990)
Removal 0.5°C 5°C 10°C 15°C 20°C 25°C 33°F 41°F 50°F 59°F 68°F 77°F
0.5 log
1.0 log
1.5 log
2.0 log
2.5 log
3.0 log
CT Values for Giardia Cyst Inactivation by Free Chlorine:
Water temperature at 20˚C (68˚F) at various pH readings
Removal < <9.0
0.6 log
1.0 log
1.6 log
2.0 log
2.6 log
3.0 log

31. Commercial Water Oxidation Best at pH over 7.
Man-made organic compounds including pesticides, VOCs, SOCs, and other micro pollutants - applied dosage of 0.5 to 5.0 mg/l recommended
Tannins, unsaturated aldehydes, humic and fulvic acids, etc. responsible for 90% of taste and odor problems - applied dosage of 1.5 mg/l recommended

32. Commercial Water Treatment
Pre-oxidation: Iron
Divalent ferrous iron (Fe2+) oxidizes to trivalent ferric iron (Fe3+), which precipitates as ferric hydroxide.
Rapid reaction.
Best at pH over 7, preferably over 7.5.
Theoretical applied ozone dosage to oxidize 1 mg/l of iron is 0.43 mg/l
If complexed with organics, recommend doubling the applied ozone dosage and increasing contact time.

33. Commercial Water Treatment
Pre-oxidation: Sulfide
Hydrogen sulfide ion is oxidized to soluble sulfate ion and in-soluble elemental sulfur.
Rapid reaction.
Independent of pH.
Theoretical applied ozone dosage to oxidize 1 mg/l of sulfide ion is 1.5 mg/l
If complexed with organics, recommend doubling the applied ozone dosage and increasing contact time.

34. Commercial Water Treatment
Pre-oxidation: Manganese
Divalent manganese (Mn2+) oxidizes to tetravalent manganese (Mn4+), hydrolyzing to insoluble managanese oxyhydroxide.
Optimum between pH range of
Theoretical applied ozone dosage to oxidize 1 mg/l of manganese is 0.88 mg/l.
Over oxidation will produce soluble permanganate ion indicated by pink water.

35. Commercial Water Treatment
Sizing an ozone system
Based upon the amount of ozone required to completely react with the contaminants being treated in the water.
Disinfection: spores and cysts - sizing based on CT values
Disinfection: bacteria and viruses mg/l applied ozone dosage
Oxidation: VOCs and SOCs to 5.0 mg/l applied dosage
Oxidation: tannins mg/l applied dosage
Pre-oxidation: iron mg/l applied dosage
Pre-oxidation: sulfide mg/l applied dosage
Pre-oxidation: manganese mg/l applied dosage

36. Commercial Water Treatment
Sizing an ozone system
Ozone systems are sized based on the principle of exact demand. To correctly size an ozone system, each contaminant and contaminant level must be accounted for.
An accurate total ozone demand is important for sizing an ozone system.
Ozone production is measured in grams per hour.
The total ozone demand and water flow rate is needed to calculate for required ozone production.

37. Commercial Water Treatment
Sizing an ozone system
Ozone demand for each contaminant is calculated by multiplying the contaminant level by the applied dosage appropriate for that contaminant.
By adding up the ozone demand for each contaminant, the total ozone demand can be found.
A safety factor of 25% should be added to the total ozone demand.

38. Commercial Water Treatment
Sizing an ozone system
With the total ozone demand and water flow rate, the following equation is used to calculate for required ozone production:
total ozone dosage X flow rate X X 19 =
grams per hour required ozone production
Where is the constant for conversion from gallons per minute to pounds per day, while 19 is the number of grams per hour in a pound per day.

40. Typical Commercial Ozone System

41. Commercial Water Treatment
Design considerations
Recommend single pass ozone injection systems for all commercial water treatment applications - larger systems will use sidetream injection
Sizing of sidestream pump is critical - oversize and take into consideration the presssure drop across the injector
Minimum +5 psi required in the sidestream after injection and contacting to re-enter the main stream

42. Commercial Water Treatment
Design considerations: contact vessels
Contact vessels are an integral part of any ozone system.
Allows time for chemical reaction to occur.
Allows time for disinfection to occur.
Allows for ozone dissolution.
Allows for off-gassing of any carrier gas and ozone not dissolved into water

43. Commercial Water Treatment
Design considerations for pre-oxidation and oxidation systems
Importance of an accurate lab analysis.
Recommend minimum 5 minutes contact time for pre-oxidation systems.
Recommend minutes contact time for oxidation systems.
Pre-filtration may be required.

44. Commercial Water Treatment
Design considerations for pre-oxidation and oxidation systems
Ozone is not a stand alone water treatment tool, post filtration is required. Recommend activated carbon or multi-media filtration for pre-oxidation systems. Activated carbon filtration for oxidation systems.
Residual sanitizer must be added for storage and delivery.

45. Commercial Water Treatment
Design considerations for disinfection:
Ozone is not a stand alone water treatment tool, pre and post filtration is required. Recommend multi-stage filtration levels down to 5 micron for pre-filtration and activated carbon for post filtration.
Always exceed EPA recommended C.T. values.
When meeting C.T. values, use lower ozone concentrations and higher contact times.

46. Commercial Water Treatment
Design considerations for disinfection:
When calculating for contact time, follow EPA guidelines for time credit - plug flow
If oxidation or pre-oxidation is required in conjunction with disinfection, two complete ozone systems with two injection points and contact/de-gas systems is recommended.
Residual sanitizer must be added for storage and delivery.

47. Commercial Water Treatment
Design considerations for disinfection:
Carcinogenic disinfection by-products may form when ozone is used in the presence of bromide ions - bromate and bromoform ions
Difficult to treat after ozonation - some forms of activated carbon may have effective adsorption or chemical reduction capacities
Low levels of ozone applied over long periods will minimize the formation of bromate ions.

48. Residential Well Water Treatment

49. Residential Wells
Ozone is typically used when more than one contaminant is present.
Typically used for pre-oxidation and oxidation.
Maybe used for disinfection of bacteria and viruses that may be found in wells with surface water intrusion.

50. Typical Residential Well Water Treatment System

51. Typical Single Pass Ozone System
Ozone Generator
Off-gas Destruct
Off-gas Vent
Vacuum Break
Pressure Tank
120V Signal from Pressure Switch
OZD
Pressure Switch
Well Pump
Water from Well Pump
Contact Tank
Injection Manifold & Check Valve Assembly
Multi-Media, Activated Carbon or Catalytic Carbon Filter Tank
Well Pump Controlled by Pressure Switch

52. Alpha Series
Complete integrated component ozone systems - single pass treatment.
Ozone Generator
Off-gas Destruct
Off-gas Vent
Vacuum Break
Pressure Tank
120V Signal from Pressure Switch
OZD
Pressure Switch
Well Pump
Water from Well Pump
Contact Tank
Injection Manifold & Check Valve Assembly
Multi-Media, Activated Carbon or Catalytic Carbon Filter Tank
Well Pump Controlled by Pressure Switch

53. Complete integrated skid mounted ozone systems - recirculated multi-pass treatment.
POE Series
Filter (optional)
Pressure Tank
Water Source (Well)
Pressure Switch
To Use

54. CWT Problem Water Ozone Demand Sizing Guideline Alpha Series
PPM Contaminant Level (from water analysis)
Ozone Dosage Required per PPM of Contaminant
Ozone Dosage Required
PPM
Contaminants
Iron (FE 2+)
Manganese (Mn 2+)
Sulfide (S 2-)
Tannins
PPM
PPM X
0.43 =
0.88 =
2.20 =
1.50 =
Ozone Dosage Required
Safety Factor For Unknown Demand
Total Ozone Dosage Required =
PPM X
1.25 =
PPM
Recommended CWT Ozone Treatment Systems (based on dosage and flow rate):
Alpha !
Alpha II
Alpha III
Dosage Rate PPM PPM PPM
Flow Rate 10 GPM max 10 GPM max 10 GPM max

55. CWT Problem Water Ozone Demand Sizing Guideline POE Series
PPM Contaminant Level (from water analysis)
Ozone Dosage Required per PPM of Contaminant
Ozone Dosage Required
PPM
Contaminants
Iron (FE 2+)
Manganese (Mn 2+)
Sulfide (S 2-)
Tannins
PPM
PPM X
0.43 =
0.88 =
2.20 =
1.50 =
Ozone Dosage Required
Safety Factor For Unknown Demand
Total Ozone Dosage Required =
PPM X
1.25 =
PPM
Recommended CWT Ozone Treatment Systems (based on dosage and flow rate):
POE10
POE15
POE20
Dosage Rate PPM PPM PPM
Flow Rate 10 GPM max 15 GPM max 15 GPM max

56. Residential Wells ALPHA and POE series sizing notes
Sizing based on dosage, residential applications only
Maximum 10 gpm flow rate for ALPHA series and 15 gpm maximum flow rate for POE series
Oxygen as an oxidizer
Long contact times
Assisted by media filtration
Residual build-up through recirculation for POE systems
Guidelines only - additional factors such as pH, temp, ORP, organic load, and other water impurities will affect ozone consumption

57. Residential Wells
Design considerations for residential well treatment systems
Importance of an accurate water analysis
Draw down test required to get exact flow rate.
Add 1.5 mg/l applied ozone dosage for disinfection of bacteria and viruses.
Ozone is not a stand alone water treatment tool, post filtration is required. Recommend activated carbon or multi-media filtration for pre-oxidation systems. Activated carbon filtration for oxidation systems.

58. Water Bottling

59. Water Bottling Thee types of water bottling systems Batch processing
Pressurized recirculation systems
Single pass system

62. Water Stores

63. Water Stores
Ozone is used to maintain water quality in post reverse osmosis storage tanks.
Inhibit growth of infectants
Oxidation and disinfection of airborne pathogens
Algae growth maintenance

66. Miscellaneous Ramblings

67. Miscellaneous Ramblings
Factors that affect system performance
Water temperature fluctuations
Changes in water contaminant parameters
Changes in flow rate
Atmospheric conditions

68. Miscellaneous Ramblings
Off-gas destruction
Off-gas monitors
Importance of monitoring for water quality using ORP or residual ozone monitors
Automation capabilities

69. Miscellaneous Ramblings
Importance of air prep
The air we breath is composed of 78% nitrogen gas, 21% oxygen gas, and 1% other gases.
When air is fed into the ozone reaction chamber, the oxygen and nitrogen molecules are split into atoms.
The air we breath is humid (H2O is present).
In a highly charged corona field, all molecules are split into atoms.

70. Miscellaneous Ramblings
Importance of air prep
The oxygen atoms combine into ozone molecules.
The nitrogen, hydrogen, and oxygen atoms combine to form nitric acid.
Nitric acid will destroy the reaction chamber from the inside out.
Nitric acid will be introduced into the water.

71. Miscellaneous Ramblings
Importance of air prep: air dryers
Air is dried to -60 degrees F dewpoint using a molecular sieve material, most commonly silica gel.
Nitrogen and oxygen atoms are still present but with the removal of moisture, the hydrogen atom is not introduced into the corona field.
Ozone concentration: 1% by weight

72. Miscellaneous Ramblings
Importance of air prep: oxygen concentrators
High volumes of compressed air is pushed through a molecular sieve which removes nitrogen and water.
Oxygen concentrations up to 95% are attainable.
Minimum -100 degrees F dewpoint.
Ozone outputs are tripled. Ozone concentration: minimum 3% by weight.

73. Thank You