ABSTRACT By

Due to the worlds growing energy concerns, biodigesters are becoming a popular alternative to oil. These digesters are turning a variety of organic wastes such as trees, plants, and food wastes into fuel by use of microorganisms. The microorganisms eventually break down the organic waste into methane or ethane, but can also produce harmful by-products during the process. This study characterized the harmful emission by-products, specifically VOCs, carbon monoxide, hydrogen sulfide, and furfural, created by the degradation of sorghum into methane to determine if the concentration emitted from the different digesters was above the occupational exposure limits. The first digester utilized a Bacillus stearothermophilus culture, Tryptic Soy Broth (TSB), and sorghum; the second digester consisted of TSB broth and sorghum; and the third digester consisted of distilled water and sorghum. The digesters were kept at 37 °C under anaerobic conditions. Two of the three digesters monitored had levels over the exposure limits for all of the by-products sampled excluding furfural. Furfural was not found as a by-product of any of the digestion processes monitored in this study