ABSTRACT:
Odor control has been an important component of the operation of the Montgomery County Regional Composting Facility. After several facility improvements, which greatly reduced off‐site odors, the discharge of compost process air remained the greatest source of odor impacts on the surrounding community. Thus, the WSSC assembled a research team to investigate methods of improving odor control treatment for the process air. The research team developed bench‐scale tests and gas chromatographic methods that provided a better understanding of the chemical basis for odor control. Organic sulfur‐containing compounds, especially dimethyl disulfide, were identified as the primary odorants in the process air. Effective removal of the reduced organic sulfides requires oxidation by sodium hypochlorite at a neutral pH. Ammonia interferes with this oxidation process and must be removed to allow effective and reliable oxidation. Hydrogen peroxide has also been used to improve oxidation and reduce chlorine odors. The removal of organic compounds has been enhanced by the use of surfactants. These findings have resulted in further full‐scale improvements to the existing compost process air scrubbing system.