Subcolloidal Fe/Ag Particles for Reductive Dehalogenation of Chlorinated Benzenes

Abstract

Subcolloidal (<0.1 μm) iron−silver (1% Ag) particles were synthesized for the transformation of chlorinated benzenes in aqueous solution. Hexachlorobenzene (HCB) (4 mg/L) was dechlorinated to tetra-, tri-, and dichlorobenzenes (TeCB, TCB, and DCB, respectively) within 24 h at a metal loading of 25 g/L. Principal degradation products included 1,2,4,5-TeCB, 1,2,4-TCB, and 1,4-DCB. Continuous dechlorination was observed during a 57-day experiment. The rate of dechlorination was positively correlated to the silver loading of the bimetallic particles. The bimetallic particles also effectively degraded penta- and tetrachlorobenzenes (PCB and TeCB, respectively). The Fe/Ag particles could become a cost-effective alternative to the previously reported Pd/Fe particles. The subcolloidal bimetallic particles may be applied in slurry reactors, in situ applications, and in combination with biological treatment for the complete degradation of chlorinated benzenes and PCBs.

Self‐assembly formation of the magic ion of (H2O)20O+: observation of nanoscale cages of oxygenated water clusters induced from iron nanoparticles

“…[26][27][28] The average size of the Fe NPs is 25 nm with diameter ranging from 5-60 nm and a surface to weight ratio of 40-60 m 2 /g. The packing density is 0.10-0.25 g/cm 3 .…”

“…[15] Nanoparticles (NPs) have been extensively investigated and applied to biochemical applications due to their large surface area to volume ratios and high surface reactivity. [26][27][28] The Fe NPs exhibit tens to hundreds times more surface reactivity than that of micro-or milli-scale Fe particles. [26][27][28] In this study, we first observed the (H 2 O) 20 O þ oxygenated water cluster ions (m/z 376) by introducing a suspension of Fe NPs in solution into an electrospray ionization mass spectrometry (ESI-MS) system.…”

“…[26][27][28] The Fe NPs exhibit tens to hundreds times more surface reactivity than that of micro-or milli-scale Fe particles. [26][27][28] In this study, we first observed the (H 2 O) 20 O þ oxygenated water cluster ions (m/z 376) by introducing a suspension of Fe NPs in solution into an electrospray ionization mass spectrometry (ESI-MS) system. Tandem mass spectrometry (MS/MS and MS/MS/MS) experiments were applied to confirm the assignments of fragment ions in order to explore the formation processes and possible structures for the m/z 376 ion.…”

In-Situ Combination of Bio and Abio Remediation of Chlorinated Ethenes

“…nZVI easily reduce organic compounds such as chlorinated ethenes [4][5][6][7][8], chlorinated ethanes [9], chlorobenzenes [10], pesticides [3], PCB [11,12]. Inorganic substances include several anions such as nitrate, phosphate and sulphate [3] and in particular heavy metals such as Cr, As, Pb and U [13][14][15] can be also stabilized by nZVI.…”

Effects of solvent, pH, salts and resin fatty acids on the dechlorination of pentachlorophenol using magnesium–silver and magnesium–palladium bimetallic systems

“…On the other hand smaller proportions of organic polar solvents have been used in aqueous reaction phase for lab scale studies. For example, Liu et al [30], Roy et al [31], Kim and Carraway [16], Xu and Zhang [32], and Doong and Rai [33,34] used acetone and methanol in various proportions (1, 0.2, 0.5, 0.05% v/v) to prepare solutions of chlorinated compounds such as, chlorophenols, PCP, chlorobenzenes, and trichloroethylene (TCE). However, the fore-mentioned publications do not provide any justification for the selection of a co-solvent or its concentration.…”