As one of the best oxidants that doesn’t leave a chemical
residual, ozone has many uses in water dependent industries. From drinking water to wastewater, marine and
ballast water, pulp and paper bleaching and treatment to pharmaceuticals, ozone
provides excellent treatment.
As a disinfectant for drinking water supplies, it does not
produce the disinfection by-products associated with chlorine. In addition, ozone breaks down precursors of
disinfection by-products (DBPs), lowering chlorine demand and preventing DBP formation
with chlorine residuals in distribution lines.
Ozone is also effective in breaking down chemicals that cause taste and
Because ozone is generated on site and is used immediately,
it does not require transport or storage, making it an excellent disinfectant
for space constrained applications. It
has many uses in the marine industry, from disinfection of drinking water
supplies, boiler feed water treatment, and ballast water treatment. In the pulp and paper industry, ozone
bleaching improves production, providing exceptional brightness and superior
pulp strength with reduced chemical and energy costs. On the wastewater side, ozone can break down (cracking)
complex COD from paper processing, making them biodegradable, as well as
breaking down color components to help meet regulatory compliance
In the pharmaceutical industry, ozone disinfects without
leaving chemical residuals or forming harmful byproducts. It also breaks down pharmaceutical residuals
(APIs and EDCs) and personal care products (PCPs), to protect the environment
and downstream drinking water supplies. In
mining, it can oxidize difficult compounds like cyanide, making them easier to
remove from waste streams.
Dissolution in water is complex
Due to the highly reactive nature of ozone, its solubility in water is not predictable by Henry’s law alone. Ozone concentration and pressure in the feed stream are key factors. Using an oxygen feed vs. an air feed into the ozone generator produces a higher ozone concentration and pressure in the feed stream. Other factors affecting solubility are temperature and pH, with solubility increasing as temperature and pH decrease. In addition, excess UV light increases ozone solubility.
Of course, all mass transfer between phases (gas and water) improves with proper mixing. Proper ozone application may use a number of advanced mixing methods such as venturis, static mixers, sidestream injection, and plug flow reactors. In the wastewater industry, advanced ceramic fine bubble diffusers transfer ozone in suspended growth systems.
Better mixing methods produce better ozone dissolution, reducing reaction time and enhancing ozone efficiency resulting in a lower applied dose. Better mixing improves the hydraulic efficiency of ozone contactors.