• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Chemically catalyzed phytoremediation of 2,4,6-trinitrotoluene (TNT) contaminated soil by vetiver grass (Chrysopogon zizanioides L.).
【24h】

Chemically catalyzed phytoremediation of 2,4,6-trinitrotoluene (TNT) contaminated soil by vetiver grass (Chrysopogon zizanioides L.).

机译：香根草（Chrysopogon zizanioides L.）对2,4,6-三硝基甲苯（TNT）污染的土壤进行化学催化的植物修复。

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

Urban sprawl in big cities often encroaches on military land, where residual toxic explosive compounds like 2, 4, 6-trinitrotoluene (TNT) in soil could pose a serious health risk. Additionally, in demilitarized areas, lack of sustainable remediation techniques hinder the much needed residential development. Phytoremediation is an environmentally safe and cost effective solution; however, the characterized low aqueous solubility of nitroaromatic compounds resulting in limited availability of TNT for plant uptake is a major constraint. To overcome this limitation, we propose a new innovative phytoremediation technique using urea, a common nitrogen fertilizer, as a chaotropic agent, to enhance the solubility of TNT in the soil solutions and thus enhancing the TNT uptake by plant. A multi-process approach was used which included (1) sorption studies to understand the retention/release of TNT in soil solutions in the presence and absence of urea, followed by (2) a greenhouse study to fully characterize the urea catalyzed uptake of TNT using vetiver grass from TNT contaminated soils. This study also aimed to investigate the enzyme-mediated plant detoxification activities and changes in the plant-proteomic profile, to provide important clues to the mechanism of stress response and the TNT-tolerance in vetiver grass. Results showed that the extent of TNT sorption and chaotropic effectiveness of urea varies with the soil properties, predominately with the soil organic matter. Urea significantly (p<0.0001) catalyzed TNT extraction from all soils, suggesting that it mobilizes soil-TNT by increasing its solubility at the solid/liquid interface. Vetiver grass showed high uptake (73%) and significant root-to-shoot translocation (38%) of TNT. Urea significantly enhanced (p<0.0001) the vetiver-TNT uptake and translocation. Within the limits of agronomic fertilizer N application rates, 125 mg kg-1 of urea was considered optimum for TNT uptake by vetiver grass (82%). However, increasing the urea rate to 1000 mg kg-1 further increased the TNT removal (91%). Major TNT metabolites, such as 2-ADNT, 4-ADNT and 1,3,5-TNB were detected in plant tissues. The enhanced nitroreductase (NR) enzyme activity in TNT treated vetiver grass suggests the role of NR mediated biochemical mechanism in transforming TNT. The optimum kinetic parameters of the NR enzymes were determined. To the best of our knowledge, this study is the first attempt to investigate the proteomic profiling of a plant under TNT stress. Root proteins showed a significant (p<0.0001) negative correlation (r=-0.97) with TNT. Proteomics technique with integrated bioinformatics approach revealed downregulation of growth-related proteins and key functional proteins involved in important cellular mechanisms like transcription, translation, ribosome biogenesis, nucleocytoplasmic transport, and protein glycosylation. Plant defense related proteins were upregulated at lower TNT treatments suggesting vetiver's innate defense mechanism against TNT stress. The highly encouraging results of the current study showed the potential of using chaotropically enhanced phytoremediation of TNT contaminated soils using vetiver grass.
机译：大城市的城市蔓延经常侵占军用土地，在土壤中残留的有毒爆炸性化合物（如土壤中的2、4、6-三硝基甲苯（TNT））可能构成严重的健康风险。此外，在非军事区，缺乏可持续的修复技术阻碍了急需的住宅开发。植物修复是一种环境安全且具有成本效益的解决方案；但是，硝基芳香族化合物的特征性低水溶性导致导致植物摄取TNT的有限性是主要限制因素。为克服此限制，我们提出了一种新的创新植物修复技术，该技术使用尿素（一种常见的氮肥）作为离液剂来增强TNT在土壤溶液中的溶解度，从而提高植物对TNT的吸收。使用了一种多过程方法，其中包括（1）吸附研究以了解存在和不存在尿素的情况下土壤溶液中TNT的保留/释放，然后（2）进行温室研究以全面表征尿素催化的TNT吸收使用来自TNT污染土壤的香根草。这项研究还旨在研究酶介导的植物排毒活性和植物蛋白质组学特征的变化，为香根草的胁迫响应和TNT耐受机制提供重要线索。结果表明，尿素对TNT的吸附程度和离液有效性随土壤性质而变化，主要随土壤有机质而变化。尿素显着（p <0.0001）催化了从所有土壤中提取TNT，表明它通过增加其在固/液界面的溶解度来动员土壤TNT。香根草显示出高的TNT吸收率（73％）和根到茎的易位（38％）。尿素显着增强了香根草TNT的吸收和转运（p <0.0001）。在农艺氮肥施用量的限制内，认为香根草对TNT的吸收最佳量为125 mg kg-1尿素（82％）。但是，将尿素比率提高到1000 mg kg-1会进一步提高TNT去除率（91％）。在植物组织中检测到主要的TNT代谢物，例如2-ADNT，4-ADNT和1,3,5-TNB。 TNT处理的香根草中增强的硝基还原酶（NR）酶活性表明NR介导的生化机制在转化TNT中的作用。确定了NR酶的最佳动力学参数。据我们所知，这项研究是研究TNT胁迫下植物蛋白质组学分析的首次尝试。根蛋白与TNT显着（p <0.0001）负相关（r = -0.97）。蛋白质组学技术与整合的生物信息学方法相结合，揭示了与生长相关的蛋白和关键功能蛋白的下调，这些蛋白与重要的细胞机制有关，如转录，翻译，核糖体生物发生，核质运输和蛋白糖基化。在较低的TNT处理下，植物防御相关蛋白上调，表明香根草对TNT胁迫的先天防御机制。当前研究的令人鼓舞的结果表明，使用香根草可以对离地层被TNT污染的土壤进行离液增强的植物修复。

著录项

  • 作者

    Das, Padmini.;

  • 作者单位

    Montclair State University.;

  • 授予单位 Montclair State University.;
  • 学科 Environmental Management.;Agriculture Plant Culture.
  • 学位 Ph.D.
  • 年度 2014
  • 页码 237 p.
  • 总页数 237
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 等离子体物理学;
  • 关键词

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