Anyone who lives in a food processing town knows which way the wind is blowing by the smells.
Odors are difficult to control but several methods can be used.
Recently we have been designing and developing biological filters to control volatile organic carbons in fumes from paint shops and other sources. I understand that biofilters are also effective for odor control. There are several suppliers. We are designing systems with capacities from 250 cfm to modules of 10,000 cfm. Several modules can be used for higher loads from process industries like particle board and fermentation plants.