• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >The impact of cadmium on a multi-species biofilm degrading naphthalene and the role of hydrogen peroxide in cadmium-biofilm interaction .
【24h】

The impact of cadmium on a multi-species biofilm degrading naphthalene and the role of hydrogen peroxide in cadmium-biofilm interaction .

机译：镉对多种降解萘的生物膜的影响以及过氧化氢在镉-生物膜相互作用中的作用。

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

Polycyclic aromatic hydrocarbons (PAHs) are of major concern because of their toxicity to human health and to natural ecology. The co-presence of heavy metal wastes may hinder or prevent the biodegradation of some of PAHs.; A macro-micro-molecular methodology was used to study the impact of cadmium on a multi-species biofilm degrading naphthalene and the role of hydrogen peroxide in the toxicity-resistance interaction between cadmium and the biofilm. The impact of cadmium and hydrogen peroxide on the biofilm was studied in batch experiments; cadmium transport and distribution and the micro-environmental profiles of dissolved oxygen and redox potential were investigated with microelectrodes; and microbial community changes in the biofilm were observed using CLSM combined with fluorescence probes.; Cd2+ sorption in the biofilms was a rapid and highly pH dependent process. Cd2+ started to transport into the biofilm once the contact started. Cd2+ penetrated the biofilm in less than one hour. Most sorption occurred during the first two hours. Naphthalene removal had good correlation with Cd2+ sorption. The biofilm behavior toward naphthalene removal could be divided into three phases. The minimum Cd2+ inhibitory capacity for the biofilms and the Cd 2+ inhibition range were defined as 5 mug Cd/mg VS and from 5 to 10 mug Cd/mg VS, respectively.; A multi-species biofilm was found to have the ability to resist external inhibitors such as Cd2+. Naphthalene removal and dissolved oxygen consumption were retarded by Cd2+ but were resumed after the retardation period. The dominant components of the microbial community switched from round/rod cells to filamentous microorganisms. However, hydrogen peroxide increased the vulnerability of the biofilm to Cd2+ toxicity. When H2O2 was present, naphthalene removal was significantly inhibited by Cd2+ and did not resume at the end of the experiment. Filamentous microorganisms, which were prolific when only Cd2+ was added, were not found to be dominant in the microbial community.; A multi-species biofilm developed a resistance upon external inhibition, by making the species that are more tolerant to Cd2+ the dominant ones. However, this resistance was prevented from developing due in the presence of H2O2 which may make the biofilm more vulnerable to Cd2+.; Key words: bioremediation, cadmium, confocal laser scanning microscopy, heavy metals, hydrogen peroxide, microelectrodes, multi-species biofilms, naphthalene, PAHs
机译：多环芳烃（PAHs）对人体健康和自然生态具有毒性，因此备受关注。重金属废物的共存可能会阻碍或阻止某些PAH的生物降解。宏观微分子方法用于研究镉对降解萘的多物种生物膜的影响以及过氧化氢在镉与生物膜之间的抗毒性相互作用中的作用。批量实验研究了镉和过氧化氢对生物膜的影响。用微电极研究了镉的迁移和分布以及溶解氧和氧化还原电势的微环境特征。 CLSM结合荧光探针观察生物膜中微生物群落的变化。生物膜中Cd2 +的吸附是一个快速且高度依赖pH值的过程。接触开始后，Cd2 +开始转运到生物膜中。 Cd2 +在不到一小时的时间内穿透了生物膜。大多数吸附发生在前两个小时内。萘的去除与Cd2 +的吸附具有良好的相关性。生物膜对萘的去除行为可以分为三个阶段。对生物膜的最小Cd2 +抑制能力和Cd 2+抑制范围分别定义为5大杯Cd / mg VS和5至10大杯Cd / mgVS。发现多种生物膜具有抵抗外部抑制剂（例如Cd2 +）的能力。萘的去除和溶解氧的消耗受Cd2 +的阻滞，但在阻滞期后恢复。微生物群落的主要成分从圆形/棒状细胞转变为丝状微生物。但是，过氧化氢增加了生物膜对Cd2 +毒性的脆弱性。当存在H2O2时，萘的去除被Cd2 +明显抑制，并且在实验结束时不再恢复。当仅添加Cd2 +时，丝状微生物多产，但在微生物群落中没有优势。通过使对Cd2 +更具耐受性的物种成为优势物种，多物种生物膜对外部抑制产生了抗性。然而，由于存在H 2 O 2而阻止了这种抗性的发展，这可能使生物膜更容易受到Cd 2+的影响。关键词：生物修复镉共聚焦激光扫描显微镜重金属过氧化氢微电极多种生物膜萘PAHs

著录项

  • 作者

    Jin, Peng.;

  • 作者单位

    University of Cincinnati.;

  • 授予单位 University of Cincinnati.;
  • 学科 Environmental Sciences.; Engineering Environmental.
  • 学位 Ph.D.
  • 年度 2007
  • 页码 165 p.
  • 总页数 165
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 环境科学基础理论;环境污染及其防治;
  • 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