• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Environmental Science and Health. A, Toxic/Hazardous Substances & Environmental Engineering >Dechlorination of polychlorinated biphenyls, naphthalenes and dibenzo-p-dioxins by magnesium/palladium bimetallic particles
【24h】

Dechlorination of polychlorinated biphenyls, naphthalenes and dibenzo-p-dioxins by magnesium/palladium bimetallic particles

机译：镁/钯双金属颗粒对多氯联苯，萘和二苯并-对二恶英的脱氯

获取原文
获取原文并翻译 | 示例
       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The contamination of sediments with polychlorinated organics such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (Dioxins) and polychlorinated naphthalenes (PCNs) remains a significant problem in many rivers, harbors, and estuarine areas in the US and around the world. In this work, rapid dechlorination of PCBs, PCNs, and Dioxins by palladium—coated magnesium (0.01% by weight Pd) has been demonstrated in pure solvent systems (10% methanol in distilled water). This reaction was investigated with the goal of developing it as a future sediment treatment method. More than 90% of the initial single PCB congeners BZ 3 and 170 were removed in 1 to 10 minutes and about 58% of the total initial Arochlor 1260 was removed in 4 minutes. The removal of single Dioxin and PCN congeners also occurred rapidly resulting in a 69 to 95% reduction in 30 minutes. Rapid removal of biphenyl, the expected degradation end product for PCBs, was also observed (80% removal in 5 minutes). Experiments conducted with Arochlor 1260 and biphenyl did not identify significant volatile fractions. A significant amount of PCBs were extracted from the filtered Mg/Pd material suggesting that PCBs first adsorb to the surface of the bimetal and then dechlorination occurs; lesser chlorinated congeners and biphenyl were also found adsorbed to the Mg/Pd material. Experiments conducted with single PCB congeners BZ 194 and 204 demonstrated the formation of lower—chlorinated PCB congeners, indicating that dechlorination was occurring. A stepwise dechlorination process was suggested in which chlorines in the ortho position were removed last.
机译：在美国和世界各地的许多河流，港口和河口地区，多氯有机物（例如多氯联苯（PCB），多氯二苯并对二恶英（Dioxins）和多氯萘（PCN））对沉积物的污染仍然是一个重大问题。 。在这项工作中，已证明在纯溶剂系统（蒸馏水中含10％的甲醇）中，钯包覆的镁（0.01％重量的Pd）可将PCBs，PCNs和二恶英快速脱氯。对该反应进行了研究，目的是将其发展为未来的沉淀物处理方法。在1至10分钟内去除了90％以上的初始单一PCB同系物BZ 3和170，在4分钟内去除了约58％的初始Arochlor 1260。单个二恶英和PCN同系物的去除也很快发生，导致30分钟内减少69％至95％。还观察到了联苯的快速降解，这是预期的多氯联苯降解最终产物，（在5分钟内去除了80％）。用Arochlor 1260和联苯进行的实验未发现明显的挥发分。从过滤后的Mg / Pd材料中提取了大量的PCB，这表明PCB首先吸附到双金属表面，然后发生脱氯；最后，脱氯开始。还发现较少的氯化同类物和联苯吸附在Mg / Pd材料上。使用单个PCB同类品BZ 194和204进行的实验表明，形成了氯化度较低的PCB同类品，表明发生了脱氯。建议采用逐步除氯工艺，其中最后除去邻位的氯。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号