title: Rapid and complete destruction of perchlorate in water and ion-exchange brine using stabilized zero-valent iron nanoparticles.
abstract: Perchlorate has emerged as a widespread contaminant in groundwater and surface water. Because of the unique chemistry of perchlorate, it has been challenging to destroy perchlorate. This study tested the feasibility of using a new class of stabilized zero-valent iron (ZVI) nanoparticles for complete transformation of perchlorate in water or ion-exchange brine. Batch kinetic tests showed that at an iron dosage of 1.8 g L(-1) and at moderately elevated temperatures (90-95 degrees C), approximately 90% of perchlorate in both fresh water and a simulated ion-exchange brine (NaCl=6% (w/w)) was destroyed within 7h. An activation energy (Ea) of 52.59+/-8.41 kJ mol(-1) was determined for the reaction. Kinetic tests suggested that Cl(VII) in perchlorate was rapidly reduced to chloride without accumulation of any intermediate products. Based on the surface-area-normalized rate constant k(SA), starch- and CMC-stabilized ZVI nanoparticles degraded perchlorate 1.8 and 3.3 times, respectively, faster than non-stabilized ZVI particles. Addition of a metal catalyst (Al, Cu, Co, Ni, Pd, or Re) did not show any reaction improvement. This technology provides an effective method for complete destruction of perchlorate in both contaminated water and brine.
authors.affiliation: Environmental Engineering Program, Department of Civil Engineering, 238 Harbert Engineering Center, Auburn University, Auburn, AL 36849, USA.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Xiong
authors.forename: Dongye
authors.initials: D
authors.lastname: Zhao
authors.forename: Gang
authors.initials: G
authors.lastname: Pan
mesh_terms: D002712:Chlorides / Q000737:chemistry; D005618:Fresh Water; D006863:Hydrogen-Ion Concentration; D007474:Ion Exchange; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D053758:Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D010472:Perchlorates / Q000737:chemistry*; D012492:Salts; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D002712:Chlorides; D010472:Perchlorates; D012492:Salts; D014874:Water Pollutants, Chemical; C017082:brine; D007501:Iron; C494474:perchlorate