What is the difference between ozone and ultraviolet disinfection?
Ozone is produced by an ozone generator.
It treats microorganisms, oxidizes organic matter, bleaches water containing humic substances, transforms the organic compounds responsible for tastes and odours.
Ultraviolet rays are generated by a UV lamp, they inactivate microorganisms.
Is it for a drinking water application?
Thank you for answering.
It is for surface water after coagulation, flocculation, decantation or filtration process; the disinfection is done by chemical oxidants like chlorine or ozone or by physical process, ultraviolet irradiation. My question is what is the difference between disinfection by ozone vs. UV light? And which oxidizer is the most effective? I think it's ozone no?
Ozone is indeed a much more powerful oxidizer than UV.
UV will disinfect the water by killing bacteria and viruses and other living microorganisms (if properly sized with sufficient contact time). For drinking water, it is used only at the end of the process, on treated water without turbidity. Ozone, on the other hand, can be used at different stages of the process (pre-ozonation or post-ozonation) because, in addition to having a bactericidal power greater than chlorine, it can address other organic parameters, eliminate odours, and break down many organic molecules (including some pesticides that can then be captured more effectively by activated carbon). But using ozone increases the risk of creating certain by-products. Ozone has many advantages but a few drawbacks (investment and real costs, presence of certain by-products, depending on raw water quality).
The choice will depend on the quality of the raw water
Be careful, neither solution has any residual effect in the water. You will have to inject chlorine (gas, bleach) into the distributed water to avoid bacteriological regrowth in the distribution network.
Thank you very much for the comprehensive answer
Just to add to what WWSteev mentioned, the benefits of UV versus ozone are: no by-products (bromates), no chemicals, operator safety (compared to possible ozone leaks) ), no toxic effect on the environment, ease of operation, no dependence on pH level, more effective action on Cryptosporidium parasites, lower energy consumption, reduced maintenance, etc.
Some disadvantages: less effective on viruses, no residual disinfection at all (a little with ozone), requires good upstream treatment (no turbidity, iron or manganese).
The choice has to be made on a case-by-case basis according to the local context: refurbished system or new plant, space available to set up 1 or more UV reactors, aging of the ozone tanks (engineering considerations), condition of ozonation equipment (air treatment, ozone production, diffusion, etc.), energy comparison of the two solutions, etc.
Completely agree with CL: ozone is a toxic product, so you need to provide for an ozone destroyer at the ventilation outlet.