Gas Purification Technology Suitable for Space Mice Cultured in Sealed Box

A stable atmosphere is very important for long-term life science experiments with small mammals in sealed habitats. In this study, we constructed a multi-stage, solid-state purification system to regulate and control the supply of oxygen and remove carbon dioxide, humidity, and trace contaminants in a sealed metal box. Lithium hydroxide was used as the material to absorb CO2; molecular sieves and humidity-indicating silica gel were used as dehumidification material; and activated carbon-based sorbent was used to remove ammonia and hydrogen sulfide. We evaluated the performance of the system by implementing a sealed culture test with mice for 7 days. The pressure, relative humidity, oxygen concentration, carbon dioxide concentration, and ammonia/hydrogen sulfide concentration in the sealed box were maintained at 101–103 kPa, 30–36%, 19–21%, <1000 ppm, and the main goal of this study was to test for single gas absorption. In the future, we will investigate the competitive effect of multi-gas mixtures.