Influence of Support Media Characteristics on Biofilm Activity in Graywater Treatment Systems for Advanced Life Support

Advanced life support systems for long-duration space missions will require efficient recycling of water and air. Biological treatment systems may be used as the initial process in a multistep recycling system. Biofilm reactors (or biotrickling filters) have been shown to be effective for treatment of air and water. A major design consideration for these reactors is the selection of biofilm support media. The main objective of this research was to evaluate the effect of three commercially available support media on biofilm activity. Biofilm activity was quantified in terms of microbial respiration, or specifically, carbon dioxide production. Results indicate that carbon mineralization did not differ significantly between media types when data were evaluated based on media volume. However, there was a significant difference in microbial activity when assessed with media surface area as an input value. The results suggest that suspended microorganisms may have contributed significantly to the carbon mineralization in the reactor. Therefore, when predicting performance of submerged biofilm reactors, liquid or media volume should be used as a key model parameter rather than media surface area. This information could prove to be useful when selecting support media and reactor volume for biofilm graywater treatment reactors." Description:5 pages