NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Dissolution kinetics of iron-, manganese-, and copper-containing synthetic hydroxyapatitesMicronutrient-substituted synthetic hydroxyapatite (SHA) is being evaluated by the National Aeronautics and Space Administration's (NASA) Advanced Life Support (ALS) Program for crop production on long-duration human missions to the International Space Station or for future Lunar or Martian outposts. The stirred-flow technique was utilized to characterize Ca, P, Fe, Mn, and Cu release characteristics from Fe-, Mn-, and Cu-containing SHA in deionized (DI) water, citric acid, and diethylene-triamine-pentaacetic acid (DTPA). Initially, Ca and P release rates decreased rapidly with time and were controlled by a non-SHA calcium phosphate phase(s) with low Ca/P solution molar ratios (0.91-1.51) relative to solid SHA ratios (1.56-1.64). At later times, Ca/P solution molar ratios (1.47-1.79) were near solid SHA ratios and release rates decreased slowly indicating that SHA controlled Ca and P release. Substituted SHA materials had faster dissolution rates relative to unsubstituted SHA. The initial metal release rate order was Mn >> Cu > Fe which followed metal-oxide/phosphate solubility suggesting that poorly crystalline metal-oxides/phosphates were dominating metal release. Similar metal release rates for all substituted SHA (approximately 0.01 cmol kg-1 min-1) at the end of the DTPA experiment indicated that SHA dissolution was supplying the metals into solution and that poorly crystalline metal-oxide/phosphates were not controlling metal release. Results indicate that non-SHA Ca-phosphate phases and poorly crystalline metal-oxide/phosphates will contribute Ca, P, and metals. After these phases have dissolved, substituted SHA will be the source of Ca, P, and metals for plants.
Document ID
20050206441
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Sutter, B.
(College Station TX 77843, United States)
Hossner, L. R.
Ming, D. W.
Date Acquired
August 23, 2013
Publication Date
March 1, 2005
Publication Information
Publication: Soil Science Society of America journal. Soil Science Society of America
Volume: 69
Issue: 2
ISSN: 0361-5995
Subject Category
Man/System Technology And Life Support
Funding Number(s)
CONTRACT_GRANT: NGT5-1229
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Life Support Systems
NASA Center JSC

Available Downloads

There are no available downloads for this record.
No Preview Available