Design and Operation of Laboratory-Scale Aerobic Composters

Regenerative life support systems are under development to reduce the need for resupply of essential commodities during long duration space missions. If higher plants are used to supply food, oxygen, and potable water, composters could be used to stabilize solid wastes, provide CO₂ and nutrients to the plants, and achieve pathogen reduction. Small-scale aerobic composting was used successfully to degrade organic compounds in inedible potato biomass. Soluble nutrients were extracted from the compost at concentrations that supported seed germination. Further work is indicated to understand the inhibitory effects of some leachates. Future composter designs should allow improved performance through better instrumentation and process control.