Dynamic and equilibrium studies of the RDX removal from soil using CMC-coated zerovalent iron nanoparticles.
Rapid chemical degradation of toxic RDX explosive in soil can be accomplished using zerovalent nanoiron suspension stabilized in dilute carboxymethyl cellulose solution (CMC-ZVINs). The effect of operating conditions (redox-potential, Fe/RDX molar ratio) was studied on batchwise removal of RDX in contaminated soil. While anaerobic conditions resulted in 98% RDX removal in 3 h, only slightly over 60% RDX removal could be attained under aerobic conditions. The molar ratio did not have any influence on the intermediate and final RDX degradation products (methylenedinitramine, nitroso derivative, N(2), N(2)O, NO(2)(-)), however, their distribution changed. Dynamic studies were conducted using a flow-through short column packed with RDX-contaminated soil and fed with CMC-ZVINs. The column was operated at two interstitial velocities (2.2 and 1.6 cm min(-1)), resulting in the 76.6% and 95% removal of the initial RDX soil contamination load (60 mg kg(-1)), respectively. While the column operating conditions could be further optimized, 95% of the RDX initially present in the contaminated soil packed in the column was degraded when flushed with a CMC-ZVINs suspension in this work.
Naja
Ghinwa
G
Department of Chemical Engineering, Faculty of Engineering, McGill University, Montreal, Quebec, Canada.
Apiratikul
Ronbanchob
R
Pavasant
Prasert
P
Volesky
Bohumil
B
Hawari
Jalal
J
D002266:Carboxymethylcellulose Sodium / Q000737:chemistry*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D053834:Explosive Agents / Q000032:analysis / Q000737:chemistry; D007501:Iron / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry*; D014227:Triazines / Q000032:analysis / Q000737:chemistry*
D053834:Explosive Agents; D012987:Soil; D012989:Soil Pollutants; D014227:Triazines; D007501:Iron; D002266:Carboxymethylcellulose Sodium; C009160:cyclonite