Control of Odors in the Brewing &
Food Processing Industries
Hydrogen sulfide (H₂S), easily recognized by its rotten egg odor, is usually responsible for most of the odor problems associated with brewery and food processing wastewater treatment. Colorless, corrosive, heavier than air, and extremely toxic, its presence raises serious workplace health and safety concerns. Below, we review the chemical treatment systems available to treat H₂S and some other non-sulfide odors.
These include nitrates and inhibitors that prevent bacteria from producing sulfides, masking agents that replace one odor with another, organic scavengers that react with reduced sulfur compounds, neutralizers that eliminate an odor’s objectionable characteristics, and metal salts that remove sulfides as metallic precipitates.
Problematic Odors for Brewing & Food Processing
Public complaints about odors can affect a brewer’s image in the surrounding community. Ultimately, these complaints may affect public relations in the greater marketplace where its products compete. Indeed, since the Clean Air Act Amendment (CAAA) went into effect, the onus has been placed on industry to reduce its odor emissions.
Within the brewery itself, the effect of odors can be observed in several definite ways:
- Safety concerns may arise about people being overcome by odors in the workplace.
- Productivity may be affected when odors or odor-producing conditions cause employees to avoid an area or neglect their duties.
- Productivity can also be affected by odors that taint food products, rendering them unsaleable.
- Equipment integrity can be threatened by the presence of many odoriferous substances that are corrosive in nature.
It should be noted that not all manufacturing facilities produce odors or experience these problems, nor are all odors noxious or toxic in nature. However, one very large segment of the odor control market does fit this description and dictate immediate and complete attention, and that involves the control of hydrogen sulfide (H2S) generation and evolution. Other non-reduced odors, such as those formed by certain compounds containing amines and other groups, also contribute to odor emissions and need to be controlled.
Odor Control in the Brewing & Food Processing Industry
Potential for odor control exists in many locations:
- Holding basins
- Waste storage tanks
- Air stripping units
- Wastewater treatment systems
- Land applications
In the brewing industry, areas such as biological air filter units and plant effluent wastewater areas generate odors that may become fugitive emissions. The use of chemical neutralizers to control these odors is regarded as an acceptable treatment option because of the minimal amount of capital investment required. Other acceptable technologies, including combustion, oxidation, and stripping, are also very efficient but require considerable capital equipment investment.
In many industrial applications outside of the brewing and food processing industries, odor control methods such as incineration, carbon adsorption, wet scrubbing, source modifications, and odor masking may be found. A chemical program will normally have a lower impact on the bottom line than immediate up-front capital expenditures. In addition, the time-lapse between odor control conception and installation is shorter. Oftentimes, a chemical program can begin within days of inception.