Biofilm Formation and Control in a Simulated Spacecraft Water System: Three Year Results 921310
Two simulated spacecraft water systems are being used to evaluate the effectiveness of iodine for controlling microbial contamination within such systems. An iodine concentration of about 2.0 mg/L is maintained in one system by passing ultrapure water through an iodinated ion exchange resin. Stainless steel coupons with electropolished and mechanically-polished sides are being used to monitor biofilm formation. Results after three years of operation show a single episode of significant bacterial growth in the iodinated system when the iodine level dropped to 1.9 mg/L. This growth was apparently controlled by replacing the iodinated ion exchange resin, thereby increasing the iodine level. The second batch of resin has remained effective in controlling microbial growth down to an iodine level of 1.0 mg/L. Scanning electron microscopy indicates that the iodine has impeded but may have not completely eliminated the formation of biofilm. Metals analyses reveal some corrosion in the iodinated system after 3 years of continuous exposure. Significant microbial contamination has been present continuously in a parallel noniodinated system since the third week of operation. Although coupon scrapings show that fewer bacteria were recovered from the electropolished coupon sides, scanning electron microscopy shows that electropolishing does not offer a significant advantage.
Citation: Schultz, J., Flanagan, D., Bruce, R., Mudgett, P. et al., "Biofilm Formation and Control in a Simulated Spacecraft Water System: Three Year Results," SAE Technical Paper 921310, 1992, https://doi.org/10.4271/921310. Download Citation
John R. Schultz, David T. Flanagan, Rebekah J. Bruce, Paul D. Mudgett, Sandra E. Carr, Jeffrey A. Rutz, M. Helen Huls, Richard L. Sauer, Duane L. Pierson
KRUG Life Sciences, NASA Johnson Space Center
International Conference On Environmental Systems
SAE 1992 Transactions: Journal of Aerospace-V101-1