...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Environmental Science & Technology >Rapid Metal-Catalyzed Hydrodehalogenation of lodinated X-Ray Contrast Media
【24h】

Rapid Metal-Catalyzed Hydrodehalogenation of lodinated X-Ray Contrast Media

机译：X射线造影剂的快速金属催化加氢脱卤

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

lodinated X-ray contrast media (ICM) are detected in natural waters at high concentrations relative to other Pharmaceuticals due to extensive use in medical diagnostics and high recalcitrance during conventional wastewater treatment. This study examines, for the first time, reductive treatment of ICM in water with hydrogen gas in combination with supported palladium and porous nickel catalysts. Kinetic experiments demonstrate rapid and complete hydrodehalogenation of both ionic (diatrizoate) and neutral (iopromide) ICM. Reaction rates in batch systems (continuous mixing, P_(H_2) = 0.1 = 0.1 MPa, 25 ℃) appear to be surface-reaction controlled and are dependent upon catalyst identity (e.g., 5 wt % versus 1 wt % Pd/ Al_2O_3) as well as the concentration of ICM and catalyst. Reaction rates are not markedly affected by ICM structure, pH, or by the presence of many common ions (Na~+, Ca~(2+), Mg~(2+), F~-, Cl~-, Br~-, ClO_4~-, SO_4~2--, HCO_3~-, and NO_3~-). In contrast, elevated concentrations of iodide, (bi)sulfide, and dissolved organic matter inhibit hydrodehalogenation of ICM. However, catalyst activity can be regained by washing the catalyst (e.g., with water, NaOCI, or alkaline solution). Catalytic reduction of ICM present in treated wastewater effluent is slower than in deionized water, but similar reaction rates are observed when the effluent is pretreated to reduce the level of dissolved organic matter. The high selectivity of reductive catalytic treatment processes suggest that this is a promising strategy for targeted treatment of ICM present in mixed waste streams and natural water matrices containing much higher concentrations of nontarget constituents.
机译：由于在医学诊断中的广泛使用以及常规废水处理过程中的高抗拒性，相对于其他药物，在天然水中检测到高浓度的X射线造影剂（ICM）。这项研究首次考察了氢气与负载型钯和多孔镍催化剂的结合对水中ICM的还原处理。动力学实验表明，离子型（泛影酸盐）和中性（碘化丙啶）ICM均可快速，完全加氢脱卤。间歇系统中的反应速率（连续混合，P_（H_2）= 0.1 = 0.1 MPa，25℃）似乎是表面反应控制的，并且取决于催化剂的同一性（例如5 wt％对1 wt％Pd / Al_2O_3），以及ICM和催化剂的浓度。反应速率不受ICM结构，pH或许多常见离子（Na〜+，Ca〜（2 +），Mg〜（2 +），F〜-，Cl〜-，Br〜- ，ClO_4〜-，SO_4〜2-，HCO_3〜-和NO_3〜-）。相反，高浓度的碘化物，（双）硫化物和溶解的有机物会抑制ICM的加氢脱卤作用。但是，可以通过洗涤催化剂（例如用水，NaOCl或碱性溶液）来恢复催化剂活性。处理过的废水中ICM的催化还原速度要比去离子水中的慢，但是当对废水进行预处理以降低溶解的有机物含量时，观察到相似的反应速率。还原催化处理过程的高选择性表明，这是一种有针对性的策略，可用于处理包含大量非目标成分的混合废物流和天然水基质中存在的ICM。

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