Ozone is the most powerful oxidizing agent and disinfectant chemical that is offered for the treatment of water. OZONE is an allotropic variety of oxygen, its triatomic molecule (O3) is generated by activation of the diatonic molecule (O2) of oxygen.
Ozone issued in water treatment for over 100 years, and if its use in this field is not more widespread is due to its greater cost with respect to the other commonly used disinfectants, however, due to the increased demands in the various regulations, especially in the reduction of by-products of disinfection, is causing a greater interest in the application of fewer byproducts originating substances in water and further reducing the flavor and smell of the treated water.
Ozone is more powerful and faster acting than chlorine, chlorine dioxide and chloramines as disinfectant.
In water purification ozone can be applied in the different phases or stages of the process: As preozonization is performed at the beginning of treatment by incorporating this into the raw water, with which, in turn an initial disinfection can eliminate iron and manganese and also help the clotting process, especially in waters with high hardness. As intermediate ozonation may be applied before filtration and in this case in addition to oxidizing natural organic matter, it favors its biological elimination in sand filters. As postozonizacion is used in the final stage to the output of the plant. Sometimes could simultaneously be used in two phases of treatment, or on the three mentioned.
Ozone acts as a very effective way in the elimination of many substances that give smell and taste to the water, as well as other that originate mostly from alcohols, aromatic aldehydes, ketones and esters.
Ozone can be applied at several points in a water treatment plant
For waters with high content of iron, manganese, acid fulvic and humicacids, there is that ozone dosing in function of DOC (dissolved organic carbon), amounts of ozone above the stoichiometric values, will be required for the elimination of manganese.
On the other hand, the elimination of manganese in this kind of water is quite influenced by the alkalinity of the environment (mg CaCO3/L), as well, in the presence of high amounts of bicarbonate, the ozone requirement is lower. The bicarbonate ion stabilizes the dissolved ozone, hydroxyl ions change or humic substances break down in hydroxyl radicals, these being of greatest potential for oxidation but less selective than molecular ozone, which is why it will take more ozone to oxidize the same amount of manganese.
The contact times in preozonization for the elimination of iron and manganese are 2 + 3 minutes, only ozone dosing in the first bay of the contact chamber.
Advantages of Preozonization:
- Improves the coagulation and flocculation.
- Improves color
- Prevents the formation of THMS's
- Helps to eliminate algae
- Removes Iron and Manganese
- Improve the odor and flavor
The ozone prior to the active carbon filters CAG, power, among other things, a better elimination of organic matter. Part of the effect of adsorption, also on the Active Carbon there is a biological effect, which develops more or less depending on the quality of the organic matter in the water, as well, the bacteria of the coal can only assimilate that matter that is biodegradable and has a size best suited to become assimilated.
The ozone before the Active Carbon benefits for two reasons:
- Decreases the size of the particle => This ensures that the subject matter that you cannot access the microporous be able to do so, and thus to ensure that the active carbon increase its adsorption capacity.
- Increases the biological nature of coal => This point is also related to the previous one, because the decrease the size of the particle part of it is converted to equivalent, thus increasing the capacity of the activated charcoal to remove M. O., THMs, previously trained with precloraciones.
- Removes the micro-pollutants
- Increases the biodegradability organic matter
- Improve the odor and flavor
- Removes halogenated compounds
- Elimination of viruses and bacteria