Testing Bioregenerative Waste Processing Approaches in BIO-Plex 1999-01-2189

The goal of the Advanced Life Support (ALS) Program’ss effort at Kennedy Space Center (KSC) is to conduct research and technology development leading to biore-generative approaches suitable for integrated human testing in the Bioregenerative Planetary Life Support Systems Test Complex (BIO-Plex) at the Johnson Space Center (JSC). One of the major elements of the KSC effort has been testing the feasibility of linking waste processing and biomass production. Research to date indicates that two approaches are viable candidates for further integrated testing. The first, direct recycling of graywater (i.e, shower and wash water) into hydroponic plant production systems, requires minimal additional costs since it utilizes processes within the plant production system (i.e., high microbial activity associated with the plant roots and plant evapotranspiration) to process and purify the hygiene water. Preliminary studies indicate that the growing area of wheat projected for the Biomass Production Chamber will be sufficient to convert the gray-water production from a crew of 4. Further studies are necessary to define the processing necessary before safe use of the condensate as potable, wash, or flush water. The second approach deals with inedible plant material which represents a potential sink of carbon and inorganic nutrients unless processed. Preliminary studies have indicated that biological processing of inedible plant residues with subsequent extraction and recycling of water soluble plant nutrients is a viable means for recovering the majority of plant nutrients and producing a stabilized, low volume solid waste suitable for storage or subsequent physical-chemical oxidation. Storage of stabilized organic waste would be of benefit if stored food is used since complete oxidation of wastes would produce excess CO₂ at the expense of available O₂. ALS program members at KSC and JSC are defining the research and engineering efforts necessary to integrate these technologies in upcoming human tests at JSC.