Introduction

Life Support
  Air, Water, and Nutrition
  Waste Management
  Mental Health
  Suits
  Radiation and Zero-G

Habitat On Mars
  Power
  Structure
  Daily Routine

The Human Factor
Life Support: Waste Management

Waste Management


The structure of the waste management systems on the spacecraft will be based on generating an entrained airstream to draw wastes away from the crew member, without contaminating the air or the crew member, and the storing of the wastes in a collection unit until the wastes can be purified and then dumped overboard. 

Urine Collection

As in Spacelab, the urine collection system will be equipped with a blower, generating a .3m3/min airstream that will carry the urine through a liquid gas separator, where air will be separated from urine. The air will be returned to the cabin and the urine will continue into the urine collection unit. From there, the urine will be stabilized and will enter the water purification/reclamation unit, and undergo filtration, sorbtion, electrochemical processes, reverse osmosis, and distillation to yield pure water for the crew. 

Faeces Collection

Collection of faeces will be conducted by means of a form fitting commode. The faeces will be directed, by airstream, into a waste collection unit, where wastes will be stabilized and prepared for purification and water reclamation.

Waste Stabilization 

Chemical treatment of wastes must ensue collection because of the microbes and labile components found within them. For water reclamation purposes, urine should be decontaminated with a mix of sulfuric acid, chromium oxide, and copper sulfate, which stabilizes labile (reactive) ammonium salts. This process should be carefully controlled and monitored, as it is highly reactive. Solid wastes can be treated with alkyldimethylbenzylammonium chloride, as this quaterny ammonium compound has detergent and bactericidal properties due to a positive charge on the organic components of the molecule. This compound is of low toxicity to humans, which makes it practical to use as a solid waste stabilizer prior to water reclamation.

Vomit

Crew members often experience space motion sickness, causing them to vomit. Vomit is a breeding ground for bacteria and should be treated with food preservatives before storage and eventual disposal. 


 
 
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Comments and questions to mission2004-students@mit.edu Last updated: 10 December, 2000