Ozone Conversions and Equations

A web resource dedicated to explaining the science behind the main ozone conversion formulas and equations.

OZONE CONCENTRATION IN WATER:

1 mg/l = 1 PPM O3 = 1 g O3/m3 water {By weight}

1 ppm (One part per million) equals one unit for every one million units of the mixture. To put it in perspective, 1 g of ozone gas dissolved in 1 m3 of water will create a concentration of 1 ppm or 1 g/m3

OZONE CONCENTRATION IN AIR BY VOLUME:

1 g O3 / m3 = 467 PPMv O3 {By volume}

This means that a concentration of 1 gram of ozone per cubic meter equals 467 parts per million by volume of ozone in the air.

1 PPMv O3 = 2.14 mg O3/m3

This indicates that 1 part per million by volume of ozone equals a concentration of 2.14 milligrams of ozone per cubic meter.

100 pphm (parts per hundred million) = 1 ppm (parts per million)

OZONE CONCENTRATION IN AIR BY WEIGHT:

100 g O3/m3 = 7.8% O3 (Approximate)
1% O3 = 12.8 g O3/m3 (Approximate)
1% O3 = 7,284 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 = 6,520 PPM Ozone

Conversion Table for Ozone Gas Phase Concentration in Oxygen

Weight %	Volume %	Concentration g/m3	Productivity g/hr at 1 l/min Gas flow
1 %	0.7 %	14.3 g/m³	0.86 g/hr
2 %	1.3 %	28.7 g/m³	1.72 g/hr
3 %	2.0 %	43.3 g/m³	2.60 g/hr
4 %	2.7 %	57.9 g/m³	3.47 g/hr
5 %	3.4 %	72.6 g/m³	4.36 g/hr
6 %	4.1 %	87.4 g/m³	5.24 g/hr
8 %	5.5 %	117.3 g/m³	7.04 g/hr
9 %	6.2 %	132.5 g/m³	7.95 g/hr
10 %	6.9 %	147.70 g/m³	8.86 g/hr
12 %	8.3 %	178.5 g/m³	10.71 g/hr
14 %	9.8 %	209.7 g/m³	12.58 g/hr
16 %	11.3 %	241.3 g/m³	14.48 g/hr
18 %	12.8 %	273.4 g/m³	16.40 g/hr
20 %	14.3 %	305.9 g/m³	18.36 g/hr
22 %	15.8 %	338.9 g/m³	20.34 g/hr
24 %	16.8 %	343.2 g/m³	22.13 g/hr
25 %	17.87 %	382.38 g/m³	22.95 g/hr

DETERMINING OZONE DOSAGE IN WATER:

To determine the required ozone production for a given water flow rate and ozone dosage, we can use the following formula:

required ozone production = (water flow rate) x (ozone dosage)

However, it’s important to ensure that the units are consistent. If the water flow rate is given in gallons per minute (GPM) and the ozone dosage is given in milligrams per liter (mg/l), we can use the following formula:

required ozone production (mg/hr) = flow rate (GPM) x 3.78 l/gal x 60 min/hr x ozone dosage (mg/l)

For example, suppose we need to dose 2 parts per million (PPM) of ozone into 40 GPM of water. We can calculate the required ozone production as follows:

required ozone production (mg/hr) = 40 GPM x 3.78 L/gal x 60 min/hr x 2 PPM = 18144 mg/h

As milligrams per hour is not a common unit used in the field, let’s change it to g/h.

18144/1000 = 18.1 g/h

Note that the 18.1 g/h of ozone will permit dosing the water with 2 PPM of ozone, but the generator ozone production may be higher due to mass transfer efficiency losses and the water’s ozone demand.

Ozone Production needed based on your water flow rate and ozone dosage (ppm)

Note: The result shows the amount of ozone in g/h needed to dose the water with the selected PPM of ozone. However, the actual ozone generator production may need to be higher due to factors such as mass transfer efficiency, water temperature, and the ozone demand of the water.

DETERMINE THE OUTPUT OF AN OZONE GENERATOR:

To determine the output of an ozone generator, we can use the following formula:

ozone production = (feed flow rate) x (ozone concentration)

For example, suppose the ozone concentration leaving the generator is 120 g/m3 and the oxygen flow rate is 5 liters per minute. The output can be calculated as follows:

ozone production = 5 L/min x 120 g/m3 x (1 m3/1,000 L) = 0.6 g/min

Since g/min is not a standard unit in the ozone industry, we can convert it to g/hr by multiplying by 60 min/hr:

0.6 g/min x 60 min/hr = 36 g/hr

Therefore, the output of the ozone generator in this example is 36 g/hr.

SAMPLE CONVERSIONS:

Convert 140 g/m3 to wt% (oxygen feed gas).

based on the conversion above, 100 g/m3 = 6.99 wt. %

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

PHYSICAL PROPERTIES STANDARD CONDITIONS (P= 1013.25 MB, T = 273.3K)

Ozone density: 2.14 kg/m3.
Oxygen density: 1.43 kg/m3.
Air density: 1.29 kg/m3.
Water density: 1 kg/m3.
Ozone Molecular weight: 48 kg·mol−1.
Oxygen Molecular weight: 32 kg·mol−1.

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