Dynamic and equilibrium studies of the RDX removal from soil using CMC-coated zerovalent iron nanoparticles

Environ Pollut. 2009 Aug-Sep;157(8-9):2405-12. doi: 10.1016/j.envpol.2009.03.019. Epub 2009 Apr 5.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carboxymethylcellulose Sodium / chemistry*
  • Environmental Restoration and Remediation / methods*
  • Explosive Agents / analysis
  • Explosive Agents / chemistry
  • Iron / chemistry*
  • Metal Nanoparticles / chemistry*
  • Soil / chemistry
  • Soil Pollutants / analysis
  • Soil Pollutants / chemistry*
  • Triazines / analysis
  • Triazines / chemistry*

Substances

  • Explosive Agents
  • Soil
  • Soil Pollutants
  • Triazines
  • Iron
  • Carboxymethylcellulose Sodium
  • cyclonite