Debromination of Decabrominated Diphenyl Ether by Resin-Bound Iron Nanoparticles

Abstract

Nanoscale zerovalent iron, n-ZVI, was found to be highly effective in reductively debrominating decabromodiphenyl ether (BDE209) at ambient conditions and without the catalysis of noble metals. A method was developed to immobilize n-ZVI particles on a cation-exchange resin. The n-ZVI coated resin was then mixed with BDE209 in a water/ acetone (1:1) solution, and the reaction was allowed to proceed for up to 10 days. The first-order rate constant of BDE209 disappearance was estimated to be 0.28 - 0.04 h(-1). The debromination was found to be stepwise, and less-brominated congeners were produced with increasing reaction time. Dechlorination of decachlorobiphenyl (PCB209) was also investigated, but the reaction rate was much slower than the debromination of BDE209. Identification of the reaction products was highly challenging and was assisted by regression equations between experimental and reference gas chromatographic relative retention times, with confirmation by high-resolution mass spectrometry and reference to quantitative structure retention relationships. For randomly selected PBDE and PCB congeners, the net charges of individual atoms were calculated using the quantum chemical computation to explore the difference in relative vulnerability of halogens at different substitution positions between PBDEs and PCBs.

Zinc dust-mediated reductive degradation of decabromodiphenyl ether

“…However, initially, reaction times were very long (5Á40 days). Later, Li has forwarded the use of nanosized iron particles bound on cation-exchange resin (27). The reaction rate of the debromination was reported to be far superior to those using micrometersized Fe particles (26).…”

Removing polybrominated diphenyl ethers in pure water using Fe/Pd bimetallic nanoparticles

“…Unidentified PBDEs can be presumptively identified by comparing relative retention time and order with those reported in the retention studies of non-BDEs including BDE207 and BDE208 [9,23], and octa-BDEs [24][25][26][27]. For BDE209 quantitative analysis, the method detection limit (MDL) was 0.01 µg$L -1 and the method recovery was greater than 80%.…”

Thermal degradation of polybrominated diphenyl ethers over as-prepared Fe3O4 micro/nano-material and hypothesized mechanism

“…1). The debromination of BDE-209 in the presence of zerovalent iron microparticles (Zhuang et al 2010) and resin-bound iron nanoparticles (Li et al 2007) also followed pseudo-first-order kinetics, with rate constants of 9.79×10 −5 min −1 (0.14 day −1 ) and 4.7×10 (Su et al 2014). The degradation behaviors of different halogenated compounds might vary in ways that are strongly dependent on the halogen substituents and chemical properties of the compounds.…”

“…Five octa-BDE peaks were found, and they were identified as , again from the available standards. It has been reported that more than five major octa-BDE congeners are rarely detected by GC after BDE-209 has been degraded, regardless of which medium the reaction has been performed in (Li et al 2007). Indeed, the same conclusion could be drawn in the present study.…”

“…In contrast, only 14 of newly produced PBDE congeners were identified when BDE-209 was photocatalytically debrominated by TiO 2 (Sun et al 2009). Only 12 of newly produced PBDE congeners were identified when BDE-209 was debrominated by resin-bound iron nanoparticles (Li et al 2007).…”