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Partitioning of Inorganic Elements Consumed by Humans Between the Various Fractions of Human Wastes: A Review and Analysis of Existing LiteratureThe nutritional requirements of humans and astronauts are well defined and show consistency, but the same cannot be said of human wastes. Nutrients taken up by humans can be considered to fall into two major categories - organic and inorganic fractions. Carbon, hydrogen, oxygen, nitrogen and sulfur are elements that are associated with the organic fraction. These elements are taken up in large amounts by humans and when metabolized released in wastes often in gaseous forms or as water. On the other hand, a large number of the elements are simply exchanged and can be accounted for in the liquid and solid wastes of humans. These elements fall into three major categories - cationic macroelements (e.g. Ca, K, Na, Mg and Si), anionic macroelements (e.g P, S and Cl), 17 essential microelements, (e.g. Fe, Mn, Cr, Co, Cu, Zn, Se and Sr). When provided in the recommended concentrations to an adult human, these elements should not normally accumulate in humans, but will be excreted in the different human wastes. Knowledge of the partitioning of these elements between the different human waste fractions is fundamental to understanding (a) how these elements can be recovered for reuse in space habitats, and (b) to developing the processors for waste management. The current literature is exhaustive but sometimes also conflicting. We have used the existing knowledge of nutrition and waste from medical literature and NASA documentation to develop a consensus to typify and chemically characterize the various human wastes. The partitioning of these elements has been developed into a functional model.
Document ID
20040021354
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Wignarajah, K.
(Lockheed Martin Space Operations Moffett Field, CA, United States)
Fisher, John W.
(NASA Ames Research Center Moffett Field, CA, United States)
Pisharody, Suresh A.
(Lockheed Martin Space Operations Moffett Field, CA, United States)
Date Acquired
August 21, 2013
Publication Date
January 1, 2003
Subject Category
Inorganic, Organic And Physical Chemistry
Meeting Information
Meeting: 33nd International Conference on Environmental Systems
Location: Vancouver, British Columbia
Country: Canada
Start Date: July 7, 2003
End Date: July 10, 2003
Funding Number(s)
CONTRACT_GRANT: NAS2-14263
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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