Influence of carbon and metal oxide nanomaterials on aqueous concentrations of the munition constituents cyclotrimethylenetrinitramine (RDX) and tungsten.
There is an increasing likelihood of interactions between nanomaterials and munitions constituents in the environment resulting from the use of nanomaterials as additives to energetic formulations and potential contact in waste streams from production facilities and runoff from training ranges. The purpose of the present research was to determine the ability of nano-aluminum oxide (Al(2)O(3)) and multiwalled carbon nanotubes (MWCNTs) to adsorb the munitions constituents cyclotrimethylenetrinitramine (RDX) and tungsten (W) from aqueous solution as a first step in determining the long-term exposure, transport, and bioavailability implications of such interactions. The results indicate significant adsorption of RDX by MWCNTs and of W by nano-Al(2)O(3) (but not between W and MWCNT or RDX and nano-Al(2)O(3)). Kinetic sorption and desorption investigations indicated that the most sorption occurs nearly instantaneously (<5 min), with a relatively slower, secondary binding leading to statistically significant but relatively smaller increases in adsorption over 30 d. The RDX sorption that occurred during the initial interaction was irreversible, with long-term, reversible sorption likely the result of a secondary interaction; as interaction time increased, however, the portion of W irreversibly sorbed onto nano-Al(2)O(3) also increased. The present study shows that strong interactions between some munitions constituents and nanomaterials following environmental release are likely. Time-dependent binding has implications for the bioavailability, migration, transport, and fate of munitions constituents in the environment.
US Army Engineer Research and Development Center, Environmental Laboratory, Vicksburg, Mississippi, USA; Rice University, Houston, Texas, USA.
Jonathon A
JA
Brame
Alan J
AJ
Kennedy
Christopher D
CD
Lounds
Anthony J
AJ
Bednar
Pedro J J
PJ
Alvarez
Andrea M
AM
Scott
Jacob K
JK
Stanley
D000327:Adsorption; D000537:Aluminum Oxide / Q000737:chemistry*; D004785:Environmental Pollutants / Q000032:analysis / Q000737:chemistry*; D053834:Explosive Agents / Q000032:analysis / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D014227:Triazines / Q000032:analysis / Q000737:chemistry*; D014414:Tungsten / Q000032:analysis / Q000737:chemistry*; D014867:Water / Q000737:chemistry
D004785:Environmental Pollutants; D053834:Explosive Agents; D037742:Nanotubes, Carbon; D014227:Triazines; D014867:Water; D000537:Aluminum Oxide; D014414:Tungsten; C009160:cyclonite
Adsorption; Environmental fate; Military; Munitions constituent; Nanomaterial