# 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 Ozone 2.14 kg/m3 Molecular Weight of Ozone 48 Density of Oxygen 1.43 kg/m3 Molecular Weight of Oxygen 32 Density of Air 1.29 kg/m3 Density of Water 1000 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

### – 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