The organic and inorganic compounds emitted from various food processing operations may become nuisances in the surroundings when they carry objectionable odors as perceived by the general public. Increased sensitivity and demand of the general public for a clean and pleasant environment and reduced land areas available for isolation of industrial operations from the public areas have forced all types of industries including the food processing industry to control odor emissions as well as toxic air pollutants.

There are two basic principles for controlling odors at a food processing plant: reduction of odors at the generation sources and removal of odors from collection air-streams before the odors are discharged into the atmosphere. Source control is always the first choice for odor control and can be effected by using low-emission processing and good housekeeping techniques. In most cases, however, removal of odors from the discharge ducts or dispensed ventilation air is necessary to remediate the odor problems.

Odors generated from the food processing & pharmaceutical plants are usually a mixture of various organic and inorganic compounds in low concentrations. Most of these compounds are reduced carbon, nitrogen and / or sulfur compounds which are not toxic and easily biodegradable. Typical odorous compounds encountered in food processing and pharmaceutical operations include aldehydes, ketones, alcohols, acids, ammonia, amines, sulfides, mercaptans and hydrogen sulfide. In some cases, the odors may also be caused by volatile organic compounds (VOCs) which are less biodegradable. The physical and chemical characteristics of specific odors are largely affected by the types of odor sources. Effective application-specific air cleaning technologies are needed to help food processors make their operations environmentally friendly.

Depending on the type of odors, a range of chemical media can be used, either acting alone or in combination for total removal of most of the undesirable smells. Dry Air Scrubbers holding virgin Activated carbon, impregnated Activated carbons and impregnated Activated alumina find extensive use in odor removal in these industries.