NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Biological removal of gaseous ammonia in biofilters: space travel and earth-based applicationsGaseous NH3 removal was studied in laboratory-scale biofilters (14-L reactor volume) containing perlite inoculated with a nitrifying enrichment culture. These biofilters received 6 L/min of airflow with inlet NH3 concentrations of 20 or 50 ppm, and removed more than 99.99% of the NH3 for the period of operation (101, 102 days). Comparison between an active reactor and an autoclaved control indicated that NH3 removal resulted from nitrification directly, as well as from enhanced absorption resulting from acidity produced by nitrification. Spatial distribution studies (20 ppm only) after 8 days of operation showed that nearly 95% of the NH3 could be accounted for in the lower 25% of the biofilter matrix, proximate to the port of entry. Periodic analysis of the biofilter material (20 and 50 ppm) showed accumulation of the nitrification product NO3- early in the operation, but later both NO2- and NO3- accumulated. Additionally, the N-mass balance accountability dropped from near 100% early in the experiments to approximately 95 and 75% for the 20- and 50-ppm biofilters, respectively. A partial contributing factor to this drop in mass balance accountability was the production of NO and N2O, which were detected in the biofilter exhaust.
Document ID
20040112694
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Joshi, J. A.
(NASA Headquarters Washington, DC United States)
Hogan, J. A.
Cowan, R. M.
Strom, P. F.
Finstein, M. S.
Janes, H. W.
Date Acquired
August 21, 2013
Publication Date
September 1, 2000
Publication Information
Publication: Journal of the Air & Waste Management Association (1995)
Volume: 50
Issue: 9
ISSN: 1096-2247
Subject Category
Environment Pollution
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Life Support Systems
Non-NASA Center

Available Downloads

There are no available downloads for this record.
No Preview Available