Palladium-catalyzed reductive dehalogenation of dissolved chlorinated aliphatics using electrolytically-generated hydrogen
Palladium-catalyzed reductive dehalogenation of dissolved chlorinated aliphatics using electrolytically-generated hydrogen
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DOI：
10.1016/s0045-6535(98)00095-2
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发表时间：
1998-08-01
期刊：
影响因子：
8.8
通讯作者：
Ruiz, R
中科院分区：
文献类型：
--
作者：
McNab, WW;Ruiz, R
最近的研究表明，在钯催化剂存在下，氯代烃被氢气还原脱卤反应迅速发生。这些反应的速度和完整性可能为地下水修复提供优势。一个实际的设计挑战是需要迅速用氢气饱和水相。为了解决这个问题，已经开发了两级处理塔（氢气发生器和催化反应器）。第一阶段由一个未分隔的电解槽组成，通过电解流入的水来产生氢气。第二阶段包含负载在氧化铝珠上的钯金属的催化剂床。该反应器已经用含有各种氯化物的地下水进行了测试。使用300 ml/min的流速和4安培的电流，在8伏的电势下，对于PCE、TCE、1，1-DCE和四氯化碳，在停留时间为2分钟的情况下，实现了大于95%的去除效率。氯仿和1，2-DCA似乎不易于通过该方法脱卤。这些结果意味着溶液中存在的溶解氧不能完全抑制氯化烃在催化剂上的还原。（C）1998 Elsevier Science Ltd.保留所有权利。
Recent studies have shown that reductive dehalogenation of chlorinated hydrocarbons by hydrogen occurs rapidly in the presence of a palladium catalyst. The speed and completeness of these reactions may offer advantages for groundwater remediation. A practical design challenge arises with the need to expeditiously saturate the aqueous phase with hydrogen. To address this, a two-stage treatment column (hydrogen generator and catalytic reactor) has been developed. The first stage consists of an undivided electrolyzer cell which generates hydrogen by electrolyzing the influent water. The second stage contains a catalyst bed of palladium metal supported on alumina beads. This reactor has been tested with groundwater containing various chlorinated aliphatics. Using a flow rate of 300 ml/min and a current of 4 amps under a potential of 8 volts, removal efficiencies greater than 95% were achieved for PCE, TCE, 1,1-DCE, and carbon tetrachloride with residence times on the order of 2 minutes. Chloroform and 1,2-DCA appear less susceptible to dehalogenation by this process. These results imply that dissolved oxygen present in solution does not completely inhibit reduction of the chlorinated hydrocarbons on the catalyst. (C)1998 Elsevier Science Ltd. All rights reserved.