Ozone Equations: Concentration and Dosage

UNITS OF MEASURE

Abbreviations For Ozone Equations

GPM Gallons per Minute
PPM Parts per Million
g/hr.Grams per Hour
SLPM Standard Liters Per Minute
% O3Percentage Ozone concentration
 g/m3Grams per Cubic Meter
CFM Cubic Feet per Minute
PPHMParts per Hundred Million

PHYSICAL PROPERTIES, STANDARD CONDITIONS: P = 101325 Pa, T = 273.3 K

Density Of Ozone2.14 kg/m3
Molecular Weight of Ozone48
Density of Oxygen1.43 kg/m3
Molecular Weight of Oxygen32
Density of Air1.29 kg/m3
Density of Water1000 kg/m3

USEFUL CONVERSION FACTORS (for water)

1000 liters  =1 m3    = 220 gallons
      1 gal     =4.546 liters = 4546 ml
      1 m3     = 35.3 ft3 = 220 gallons

OZONE CONCENTRATION IN WATER

1 mg/l =

1 ppm O3 

= 1 g O3/m3 water (by weight)

OZONE CONCENTRATION IN AIR BY VOLUME

1 g O3/m3 =

 467 ppm O3 

1 ppm O3 =

 2.14 mg O3/m3

100 pphm =

 1 ppm

OZONE CONCENTRATION IN AIR BY WEIGHT

100 g O3/m3 =

 7.8% O3 (approximate)

1% O3 =

 12.8 g O3/m3 (approximate)

1% O3 =

 7284 ppm ozone

OZONE CONCENTRATION IN OXYGEN BY WEIGHT

 100 g O3/m3 =

 6.99% O3 (approximate)

1% O3 =

 14.3 g O3/m3 (approximate)

1% O3 =

 6520 ppm ozone

ADJUST FLOW RATE CONVERSION

– DETERMINING OZONE DOSAGE IN WATER:

 Water Flow Rate x Ozone Dosage = Required Ozone Production

 
UNITS CONSISTENCY IS VERY IMPORTANT: 

Below is the formula for determining ozone generation requirements if you know the common water and ozone parameters (namely flow rate in GPM and ozone dosage in mg/l).

Flow rate (gpm) x 3.75 l/gal x 60 min/hr. x ozone dosage (mg/l) =  ozone production (mg/hr.)
 

Let’s work through an example:

How much ozone production is needed to dose 2 ppm into 20 GPM of water? (We will be using ppm throughout the rest of this example knowing that 1 mg/l = 1 ppm)

20 GPM x 3.75 l/gal x 60 min/hr. x 2 ppm = 9084 mg/hr. ( gm/hr.)

Remember that 9 mg/hr. will permit you to dose the water with 2 ppm of ozone. This does not mean that 2 ppm will be your final dissolved ozone concentration. Due to efficiency losses with injecting ozone and ozone demand of the water, your dissolved ozone concentration will be less.

– DETERMINE THE OUTPUT OF AN OZONE GENERATOR:

 Flow rate (lpm) x ozone concentration (g/m3) = ozone production (mg/hr.)

Let’s work through an example:

The ozone concentration exiting an ozone generator is 120 g/m3 at 5 l/min of oxygen flow. What is the output?


5 l/min x 120 g/m3 x (1 m3/1000 l) = 0.60 g/min


g/min are not normal units in the ozone industry so we simply convert minutes to hours to get g/hr.: 0.60 g/min x 60 min/hr. = 36 g/hr.

 

SAMPLE CONVERSIONS:

Convert 140 g/m3 / 100 g/m3 x 6.99 wt. % = 9.8 wt. %

Source: Ozone Solutions

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