Odor issues are a common problem in production facilities. Unfortunately, this issue affects not only the manufacturer, but its neighboring residents and businesses as well. Odor complaints can often overshadow the otherwise solid reputation of a company.
Odors are caused by airborne chemicals. The types of wastes and treatment technologies used to deal with those wastes will determine what odors are emitted from the plant. The first step in odor prevention is to perform a survey of production and waste treatment facilities to determine which locations are potential odor sources.
Once these sources have been isolated, the odorous air will need to be treated to remove the odor-causing contaminants prior to discharge to the environment. The most effective treatment method will depend upon the volume of odorous air and the type of chemical contaminant contained in the odorous air stream. Following are the most commonly used odor control technologies.
A scented chemical is sprayed into the air to mask the smell of the odorous air. This method is often utilized near garbage dumpsters or in small open tanks. It does not eliminate odors, but instead attempts to make the odor smell better.
The odorous air is forced through a container filled with some type of adsorption media, such as activated carbon. The adsorption media allows the air to flow through, but traps the larger odor-causing chemical compounds, thus removing them from the air stream.
A tank is filled with some type of rock or plastic media. A liquid stream is pumped into the tank from the top and the odorous gas stream is pumped in at the bottom. The gradient interface between the liquid and gas strips the odor-causing compounds from the gas stream.
Organic odor-causing compounds are destroyed through combustion. The system uses either a catalytic or thermal combustion unit and reduces the odor-causing compounds to carbon dioxide, water vapor, and other non-odor causing compounds.
This oxidation system uses ozone as an oxidant instead of chlorine or other chemicals. Ozone is injected into the odorous air stream and oxidizes organic odor causing compounds, converting them to carbon dioxide, water vapor, and non odor-causing substances.
Microorganisms are used to degrade organic odor-causing compounds, thus removing them from the odorous air stream. Biofilters can be either a canister-type or a soil bed. Both systems typically use wood chips as a medium to support bacteria growth.
In general, if an odor is caused by organic compounds and space is readily available, the biofilter is the best option for low maintenance, dependability, and cost. Other systems should be considered for more extensive odor problems.
|Masking||Small||$||Combined smell may be worse than original odor|
|Adsorption||All sizes||$$$||Medium needs to be replaced regularly|
|Wet Scrubbing||All sizes||$$$||Increased water/chemical usage|
|Incineration||Medium-Large||$$$||High energy usage|
|Ozonation||Small-Medium||$$||Health and safety issues|
|Biofilters||All sizes||$||Require minimal maintenance|