Most of our discussions regarding ozone have been focused on water treatment. Ozone is also used in air treatment to reduce or eliminate odors. Many consumers may be familiar with ozone based systems for cleaning air in the homes, but municipal and industrial applications have also benefited from the use of ozone based odor control systems. In this post we will briefly discuss the application of ozone and ozone generators for this purpose.
Odor tends to be a nuisance issue for industrial and municipal facilities. While the facilities may have initially been isolated from the population, the expansion of residential areas may have brought people closer to the plants. Odors which may initially have gone unnoticed are not a problem with the local population. Odor control systems become necessary to maintain good relations with the neighboring population. There are a wide variety of odor control systems for these situations. We will focus on ozone based systems in this blog.
As we have mentioned before, ozone is powerful oxidizer. Many odor compounds can be oxidized to a non odorous state. These compounds include hydrogen sulfide (H2S) and other sulfur containing compounds such as mercaptans that produce the smell of rotten eggs. Other organic compounds such as amines can also be treated with ozone to reduce or eliminate odors.
Ozone is employed for odor control in two basic ways: First, ozonated air can mixed with the contaminated air in a contact chamber for a gas phase reaction. The contact chamber will have a packing that will provide surface area for the reaction as well as enough volume to reduce the gas velocity to allow the reaction to take place. The second approach is to use a wet chemical scrubber. In this approach a scrubbing liquid is used to capture the contaminant. Ozone is added to the scrubbing liquid to allow for a liquid phase reaction with the contaminant. For hydrogen sulfide, the scrubbing liquid would be an alkaline liquid to capture the acidic gas. The reaction with ozone would convert the sulfide into an odorless sulfate.
The choice of which approach is best depends on the flow rate of the air and the concentration of the contaminant. Lower flow rates and lower concentrations favor the gas phase treatment method. Higher concentration of odor compounds favor wet scrubbers. Ozone based odor control systems offer the following advantages over other systems:
- Small footprint
- Low initial capital investment
- Do not produce any toxic byproducts, ozone breaks down into oxygen
- Quick start-up
Spartan Environmental Technologies supplies both dry and wet ozone based odor control systems.