What process is used to control odors in sewage systems?

The process of biofiltration is widely utilized to control odors in sewage systems. This method involves the use of biologically active materials to capture and degrade odorous compounds present in the air, thereby reducing unpleasant smells associated with sewage treatment. In biofiltration, contaminated air is passed through a filter medium that supports microbial growth, which in turn metabolizes the odorous substances. This method not only helps in odor control but also improves air quality around sewage treatment facilities.

Biofiltration is particularly effective because it capitalizes on the natural processes of microorganisms, allowing for a sustainable and efficient odor management system. The biological activity within the filter medium can continuously break down various volatile organic compounds and other odorous substances, making it a preferred choice for many treatment plants looking to mitigate odor emissions.

Other methods, such as odor neutralization, typically involve the application of chemicals to mask or eliminate odors, rather than removing the sources biologically. The activated sludge process, while critical for treating wastewater, primarily focuses on the removal of organic matter and nutrients and does not specifically target odor control. Similarly, settling tanks are designed for solid-liquid separation and do not have a role in controlling odors.