Spartan Environmental Technologies supplies ozone generators for ozone disinfection applications including drinking
water, cooling water, process water, aquaculture, marine parks among many other applications.
Below you will find technical information on how ozone disinfects and how it compares to other commonly used disinfectants. If you are interested in specific organisms inactivated by ozone you can follow the link: micro organisms inactivated by ozone. We also have a link to fish pathogens inactivated by ozone.
Ozone functions as both an oxidant and disinfectant in the treatment of drinking (potable) water and wastewater. This is
similar to chlorine. Chlorine and Ozone, however, operate by different mechanisms when disinfecting water. As a result,
ozone and chlorine can act synergistically.
Ozone's germicidal properties are associated with its high oxidation potential. Disinfection by ozone is a direct result of bacterial cell wall disintegration, also known as lysis. This mechanism is different than that by chlorine. Although the exact chemical action of chlorine is not clear, it is believed that the chlorine residual in aqueous solution diffuses through the cell wall of the microorganisms and attacks the enzyme group which results in the destruction of the microorganism.
The graphics below illustrate the process while the photomicrograph show actual bacteria before and after ozonation:
To demonstrate the disinfection power of ozone and compare it with other oxidizing agents, Morris developed the lethality
Lethality Coefficient= 4.6/(Ct99) where:
C = residual concentration in mg/L t99 = time in minutes for 99 percent microorganism destruction (2-log destruction)
Morris, J.C., "Aspects of the Quantitative Assessment of Germicidal Efficiency," in Chap. 1, J.D. Johnson (ED.), Disinfection, Water and Wastewater, Ann Arbor Science, Ann Arbor, MI 1975.
The table below lists parameters for disinfection by ozone for different organisms:
|Parameters for Disinfection by Ozone (pH 7; 10-15 degrees C):|
|Organism||Lethality Coefficient (a)||C 99:10 (b)|
|Lethality Coefficient at 5 degrees C [(mg/liter)-1(min.)-1]|
|Agent||Enteric Bacteria||Amoebic cysts||Viruses||Spores|
|HOCl as Chlorine||20||0.05||>1||0.05|
|OCl- as Chlorine||0.2||0.0005||<0.02||<0.0005|
|NH2Cl as Chlorine||0.1||0.02||0.005||0.001|