title: Reduction of dinitrotoluene sulfonates in TNT red water using nanoscale zerovalent iron particles.
abstract: OBJECTIVE
  This research was designed to investigate the feasibility of converting the dinitrotoluene sulfonates (DNTS) in TNT red water into the corresponding aromatic amino compounds using nanoscale zerovalent iron (NZVI).
  
  
  METHODS
  NZVI particles were simultaneously synthesized and stabilized by sodium borohydride reduction in a nondeoxygenated system. The morphology, elemental content, specific surface area, and crystal properties of the NZVI were characterized before and after the reaction by environmental scanning electron microscope; energy dispersive X-ray; Brunauer, Emmett, and Teller; and X-ray diffraction, respectively. The reduction process was conducted at pH = 6.3 at ambient temperature. The efficiency of the NZVI-mediated DNTS reduction process was monitored by HPLC, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy analyses.
  
  
  RESULTS
  The properties of the NZVI particles prepared were found to be similar to those obtained through oxygen-free preparation and inert stabilization processes. Both 2,4-DNT-3-sulfonate (2,220 mg L(-1)) and 2,4-DNT-5-sulfonate (3,270 mg L(-1)) in TNT red water underwent a pseudo-first-order transformation when mixed with NZVI at room temperature and near-neutral pH. Their observed rate constants were 0.11 and 0.30 min(-1), respectively. Within 1 h of processing, more than 99% of DNTS was converted by NZVI-mediated reduction into the corresponding diaminotoluene sulfonates.
  
  
  CONCLUSIONS
  NZVI can be simultaneously prepared and stabilized in a nondeoxygenated system. NZVI reduction is a highly efficient method for the conversion of DNTS into the corresponding diaminotoluene sulfonates under near-neutral pH conditions. Therefore, NZVI reduction may be useful in the treatment of TNT red water and subsequent recovery of diaminotoluene from explosive wastewater.
authors.affiliation: Department of Environmental Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871, China.
authors.forename: Shi-Ni
authors.initials: SN
authors.lastname: Zhu
authors.forename: Guo-Hua
authors.initials: GH
authors.lastname: Liu
authors.forename: Zhengfang
authors.initials: Z
authors.lastname: Ye
authors.forename: Quanlin
authors.initials: Q
authors.lastname: Zhao
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
mesh_terms: D020240:Apraxia, Ideomotor; D004136:Dinitrobenzenes / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D010084:Oxidation-Reduction; D013451:Sulfonic Acids / Q000737:chemistry; D014303:Trinitrotoluene / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D004136:Dinitrobenzenes; D013451:Sulfonic Acids; D014874:Water Pollutants, Chemical; D014303:Trinitrotoluene; C016403:2,4-dinitrotoluene; D007501:Iron