Biotreatment of Organic and Inorganic Odors
Air emissions from manufacturing operations and waste treatment plants often consist of a combination of odors and volatile chemicals. Odors are inorganic or organic compounds, which are present in low concentrations, typically 20 ppmv or less, which have an unpleasant odor. Volatile chemicals are often present at higher concentrations than odors, but may or may not have any odors associated with them. The major problem with emission of volatile chemicals is the detrimental impact on the environment and adverse human health effects. While several U.S. EPA and OSHA regulations govern the emission of hazardous volatile chemicals in the ambient air and in the workplace, odor emissions are often a major nuisance to the plant workers and surrounding communities. In recent years, biological treatment has emerged as a major contender for in-process or end-of-pipe treatment, as compared with other treatment technologies, such as chemical oxidation, adsorption, gas absorption, or thermal oxidation. Major advantages of biological treatment are ambient temperature and pressure operation, no generation of toxic by-products requiring disposal or further treatment, and favorable economics. Disadvantages associated with biological treatment are upsets due to inactivation of active microbial cultures, and lack of adequate knowledge to operate the process at peak capacity and performance level. In this paper, the application of biotreatment for controlling emissions of odors and volatile organics will be addressed.