title: Enhanced desorption of RDX from granular activated carbon.
abstract: Several methods (cosolvents, surfactants, and cyclodextrins) were compared for improving desorption of a high explosive, RDX, from granular activated carbon (GAC). In batch desorption tests, 3% of the adsorbed RDX (initially 71.1 mg RDX/g GAC) was desorbed by water over 11 days, compared to 92.6% desorption by 100% ethanol. Solutions of ethanol or methanol in water also effectively desorbed RDX, although methanol was somewhat less effective than ethanol. Sodium dodecyl sulfate desorbed as much as 70% of the adsorbed RDX, while the non-ionic surfactants Tween 80, Triton X-100, and Brij 30 desorbed as much as 42 to 51% of the RDX. In continuous flow column tests, GAC was partially regenerated. One-half of the adsorbed RDX was desorbed by 2100 bed volumes (BV) of 10% ethanol, compared to the 22 500 BV of buffered water. Column modeling indicated that competitive adsorption and altered equilibrium conditions combined to enhance RDX desorption.
authors.affiliation: Department of Civil Engineering, University of Nebraska Lincoln, 68588-0531, USA. mmorley2@unl.edu
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Morley
authors.forename: Gerald E
authors.initials: GE
authors.lastname: Speitel
authors.forename: Mostafa
authors.initials: M
authors.lastname: Fatemi
mesh_terms: D000327:Adsorption; D002606:Charcoal / Q000737:chemistry*; D003505:Cyclodextrins / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry; D000432:Methanol / Q000737:chemistry; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D012997:Solvents / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*; D014227:Triazines / Q000737:chemistry / Q000302:isolation & purification*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D003505:Cyclodextrins; D012997:Solvents; D013501:Surface-Active Agents; D014227:Triazines; D014874:Water Pollutants, Chemical; D002606:Charcoal; D012967:Sodium Dodecyl Sulfate; D000431:Ethanol; C009160:cyclonite; D000432:Methanol