Essay On Disinfection By Ozone

4.4 Disinfection by ozone

The atmospheric oxygen is in molecular form containing two atoms of oxygen. But when a high-tension electric current is passed through a stream of air in a closed chamber, triatomic molecules of oxygen are formed as shown by the following equation: O2 + O  O3

Such oxygen is called ozone. The third atom is very loosely bound and the ozone easily breaks down into oxygen and releases nascent oxygen which is very powerful in killing bacteria. The ozone also unites with organic matter and it is thus effective in the removal of organic matter also. The advantage of ozone treatment is that ozone is unstable and it does not remain in the water when it reaches the consumer. Ozone as such is a powerful agent, bleaching agent and bactericide.

4.4.1 Process details

Ozone (O3) is generated on-site at water treatment facilities by passing dry oxygen or air through a system of high-voltage electrodes. Ozone is one of the strongest oxidants and disinfectants available. Its high reactivity and low solubility, however, make it difficult to

Extensive studies on various factors affecting Giardia muriscyst inactiva-tion by ozone are reported. These encompass factors like temperature, turbidity, pH, ozone dose, and contact time. It was found that residual and utilised ozone both had important influences in G. muriscyst inactivation. Encephalitozoon intestinalis, a microsporidian pathogen for humans and animals that is detected in surface water, has been listed as a major potential emerging waterborne pathogen by the USEPA. Ozone has been very effective in rendering these spores inactive, and its CXT values were an order of magnitude lower than the CXT values of chlorine in a comparative study (John et al., 2005).Ozone has several advantages, such as being one of the strongest oxidants, not producing chlorinated THMs or HAAs, and being effective against Cryptosporidium, to name