Civil Engineering - Water Supply Engineering - Discussion

The correct answer is A.

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Option A is correct.

There are several disinfection methods which can be applied to high water flows. They can be divided.

Into three main groups:

βUV radiation.
β Ozone.
βChlorine.

The first two groups do not generate significant Disinfection By-Products (DBP\'s) nor interact.

Significantly with the water, they are supposed to disinfect. Despite their efficient disinfecting.

Qualities, they do not guarantee a long-term disinfection, up until the water reaches the consumer Chlorine disinfection, on the other hand, presents the advantages of efficiency and durability.

The concept of Residual Concentration of Disinfectant is associated with disinfection durability. In fact, so as to guarantee the water supply system's disinfection, we need a residual concentration disinfectant to prevent recontamination by pathogenic or indicator micro-organisms, which can Originate in the biofilm formed inside the system, as well as in negative pressure areas (created by Pipe cracks, fissures, etc).

Ozone is 12 times less soluble in water than chlorine, so the maximum disinfectant concentrations you can reach are much lower when you use ozone. Moreover, ozone breaks down very rapidly, and the higher the temperature or the pH, the more rapidly it decays. If the water is rich in organic compounds or suspended solids, a lot of the ozone may be consumed through reactions with these other contaminants, leaving an insufficient amount available to destroy germs. That's why ozone is not an economical option for wastewater with very high amounts of suspended solids or total organic compounds.

Please explain the correct answer.

The Answer should A.

The correct Answer is A.

Ozone method is very costly, that's why we use chlorination.

Ozone treatment isn't widely used for municipal water supplies because it disappears too quickly, making it unreliable for maintaining water safety over long distances.