Dehalogenation of polybrominated diphenyl ethers and polychlorinated biphenyl by bimetallic, impregnated, and nanoscale zerovalent iron.
Dehalogenation of polybrominated diphenyl ethers and polychlorinated biphenyl by bimetallic, impregnated, and nanoscale zerovalent iron.
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通过双金属，浸渍和纳米级的杂脂铁对多溴二苯基醚和多氯联苯的脱盐化。
DOI：
10.1021/es104312h
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发表时间：
2011-06-01
影响因子：
11.4
通讯作者：
Luthy, Richard G.
中科院分区：
文献类型：
--
作者：
Zhuang, Yuan;Ahn, Sungwoo;Seyfferth, Angelia L.;Masue-Slowey, Yoko;Fendorf, Scott;Luthy, Richard G.
合成了纳米级零价铁颗粒 (nZVI)、双金属纳米颗粒 (nZVI/Pd) 和 nZVI/Pd 浸渍活性炭 (nZVI/Pd-AC) 复合颗粒，并研究了它们去除多溴二苯醚 (PBDE) 和/或多氯联苯 (PCB) 的有效性。 nZVI 的钯化促进了单溴二苯醚至三溴二苯醚和 2,3,4-三氯联苯 (PCB 21) 的脱卤动力学。与 nZVI 相比，以二苯醚为主要反应产物的三、二和单 BDE 的 nZVI/Pd 的铁归一化速率常数分别高出约 2、3 和 4 个数量级。反应动力学和途径表明了氢原子转移机制。 nZVI/Pd 的反应途径有利于优先去除 PBDE 和 PCB 上的仲卤素。 nZVI/Pd-AC 的 X 射线荧光图谱表明，Pd 主要沉积在颗粒的外部，而 Fe 存在于整个活性炭颗粒中。虽然 BDE 21 被快速吸附到活性炭复合材料上，但与自由分散的 nZVI/Pd 的反应相比，脱溴速度较慢。我们的 XPS 和化学数据表明，活性炭中约 7% 的总铁是零价铁，这表明在微孔材料中原位合成大部分零价铁存在困难。可能阻碍与 nZVI/Pd-AC 反应的相关因素是 nZVI 和 Pd 在活性炭上的不均匀分布和/或疏水性有机污染物在吸附位点的固定，从而抑制与 nZVI 的接触。
Nanoscale zerovalent iron particles (nZVI), bimetallic nanoparticles (nZVI/Pd), and nZVI/Pd impregnated activated carbon (nZVI/Pd-AC) composite particles were synthesized and investigated for their effectiveness to remove polybrominated diphenyl ethers (PBDEs) and/or polychlorinated biphenyls (PCBs). Palladization of nZVI promoted the dehalogenation kinetics for mono- to tri-BDEs and 2,3,4-trichlorobiphenyl (PCB 21). Compared to nZVI, the iron-normalized rate constants for nZVI/Pd were about 2-, 3-, and 4-orders of magnitude greater for tri-, di-, and mono-BDEs, respectively, with diphenyl ether as a main reaction product. The reaction kinetics and pathways suggest an H-atom transfer mechanism. The reaction pathways with nZVI/Pd favor preferential removal of para-halogens on PBDEs and PCBs. X-ray fluorescence mapping of nZVI/Pd-AC showed that Pd mainly deposits on the outer part of particles, while Fe was present throughout the activated carbon particles. While BDE 21 was sorbed onto activated carbon composites quickly, debromination was slower compared to reaction with freely dispersed nZVI/Pd. Our XPS and chemical data suggest about 7% of the total iron within the activated carbon was zero-valent, which shows the difficulty with in-situ synthesis of a significant fraction of zero-valent iron in the micro-porous material. Related factors that likely hinder the reaction with nZVI/Pd-AC are the heterogenous distribution of nZVI and Pd on activated carbon and/or immobilization of hydrophobic organic contaminants at the adsorption sites thereby inhibiting contact with nZVI.
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影响因子：
4.1
作者：
Ciparis, S;Hale, RC
通讯作者：
Hale, RC
影响因子：
11.4
作者：
Li, An;Tai, Chao;Hu, Jingtian
通讯作者：
Hu, Jingtian
影响因子：
11.4
作者：
Ahn, S;Werner, D;Luthy, RG
通讯作者：
Luthy, RG
影响因子：
11.4
作者：
Choi, Hyeok;Al-Abed, Souhail R.;Agarwal, Shirish
通讯作者：
Agarwal, Shirish
影响因子：
11.4
作者：
Chun, Chan Lan;Baer, Donald R.;Penn, R. Lee
通讯作者：
Penn, R. Lee