Industrial Odor Control System

General Information About Odor Control

A serious problem for sewage plant operations is the generation of foul-smelling odors, especially in a residential area. Studies have shown that air pollution from odors is the greatest problem that these installations must deal with and for which they receive the most complaints from the local population.

The substances responsible for the odors near treatment plants are generally gaseous inorganic products or highly volatile organic compounds. The inorganic substances are mainly the result of biological activity in the sewage treatment process, the latter are often caused by the presence of industrial wastes in the sewer.

Compounds such as mercaptans, skatoles, aldehydes, ketones, and inorganic acids are recognized as being among the causes of bad-smelling odors at the outlet of sewer lines and in treatment plants. In general, these compounds contain nitrogen or sulfur atoms. Ammonia and hydrogen sulfide are considered to be the main causes of foul odors. Hydrogen sulfide is considered to be the main cause when sewage comes mainly from households. Its presence is related to the onset of putrefaction in reducing environments characterized by low values of the oxidation-reduction potential.

Industrial Odor Control Process Diagram

The carrier gas (air) is washed with an oxidizing reagent to eliminate the micro-pollutants in the air. The process is called “chemical scrubbing”. The DESOZONE process uses ozone as the oxidizer because it is much more efficient than the other chemical oxidants.

The optimum system involves a basic (sometimes acid) absorption process and oxidizer. The contact system is critical to ensure the correct gas-liquid transfer and chemical reactions. A poor gas-liquid transfer process will prevent the complete elimination of the odors. The plant configuration uses horizontal scrubbers that are well-suited for most environments.

In the scrubber, a diluted caustic soda solution is the washing fluid. This eliminates bad-smelling acid molecules such as hydrogen sulfide and mercaptans. Adding an oxidizer to the scrubbing liquid will also make it possible to simultaneously oxidize the other odor-causing compounds. The ozone-containing solution is uniformly distributed in the scrubber using spray nozzles. Ozone gas at the pressure of the ozone generator is introduced into the scrubber using a static mixer. A special static mixer mixes the oxidizer with the liquid to be oxidized.

The plant is equipped with level controllers (on the scrubbing liquid containment tank and the basic solution storage tank) that permit the addition of make-up water and prevent the system from running dry. The pH of the liquid system is controlled through the pH probe, and its signal is transmitted to the dosing pump, which maintains the pH at the desired control point.

With experience in many industrial deodorization projects already successfully completed, Spartan and its partner, De Nora, can ensure safe and effective designs for the most complicated systems. Contact Spartan Environmental Technologies with questions about industrial odor control solutions or request a quote.