• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>Water Pollution IX : Modelling, Monitoring and Management >Degradation of chlorinated butenes and butadienes by granular iron
【24h】

Degradation of chlorinated butenes and butadienes by granular iron

机译：粒状铁降解氯化丁烯和丁二烯

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

Sites where chlorobutyl rubber is produced have the potential to release a mixture of chlorinated butenes and butadienes, which are known to be toxic and persistent, into the groundwater environment. The potential contaminants include trans-1,4-dichlorobutene-2 (1.4-DCB-2), 3,4-dichlorobutene-1 (3,4-DCB-1), 2,3,4-trichlorobutene-1 (2,3,4-TCB-1), 2-chlorobutadiene-l,3 (chloroprene) and 2,3-dichlorobutadiene-1,3 (DCBD). Granular iron has been shown to reductively dechlorinate a number of compounds and has been used in permeable reactive barriers (PRBs) for in-situ groundwater remediation. To evaluate the possibility of using granular iron for the remediation of the above contaminants, a series of batch experiments were conducted. Results show that dechlorination reactions for chlorinated butenes closely followed pseudo-first-order kinetics with normalized half-lives ranging from 5.1 to 7.5 h. Chlorinated butadienes degraded much slower in batch tests with normalized half-lives ranging from 38.8 to 128 h. Chlorine mass balance calculations showed that 1,4-DCB-2, 3,4-DCB-1 and chloroprene were fully dechlorinated by granular iron. 2,3,4-TCB-1 was transformed to chloroprene as an intermediate via a reductive P-elimination pathway. Neither the presence of CaCO_3 nor temperature affected degradation rates suggesting that mass transport to iron surfaces was limiting degradation in batch tests. A column experiment was conducted on 3,4-DCB-1 and a normalized half-life of 1.6 min was found. Faster degradation in the column was thought to be due to enhanced mixing effects. 3,4-DCB-1 was converted to 1,3-butadiene via reductive p-elimination, which was then converted to a mixture of 1-butene, cis-2-butene and trans-2-butene via catalytic hydrogenation.
机译：生产氯丁橡胶的场所有可能将已知有毒且持久的氯化丁烯和丁二烯的混合物释放到地下水环境中。潜在的污染物包括反式1,4-二氯丁烯-2（1.4-DCB-2），3,4-二氯丁烯-1（3,4-DCB-1），2,3,4-三氯丁烯-1（2， 3，4-TCB-1），2-氯丁二烯-1，3（氯丁二烯）和2，3-二氯丁二烯-1，3（DCBD）。粒状铁已被证明可对多种化合物进行还原脱氯，并已用于渗透性反应性屏障（PRB）中，用于原位修复地下水。为了评估使用粒状铁修复上述污染物的可能性，进行了一系列分批实验。结果表明，氯化丁烯的脱氯反应紧密遵循拟一级反应动力学，标准半衰期为5.1至7.5 h。在分批测试中，氯化丁二烯的降解慢得多，归一化半衰期为38.8至128小时。氯气质量平衡计算表明，1,4-DCB-2、3,4-DCB-1和氯丁二烯已被粒状铁完全脱氯。 2,3,4-TCB-1通过还原性P消除途径转化为氯丁二烯作为中间体。 CaCO_3的存在和温度都不会影响降解速率，这表明在批测试中向铁表面的传质没有限制降解。在3,4-DCB-1上进行了柱实验，发现标准化的半衰期为1.6分钟。认为柱中更快的降解归因于增强的混合效果。 3,4-DCB-1通过还原性p-消除反应转化为1,3-丁二烯，然后通过催化氢化反应将其转化为1-丁烯，顺式-2-丁烯和反式-2-丁烯的混合物。

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