• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Factors influencing the microbial mineralization of polycyclic aromatic hydrocarbons in coastal marine sediments.
【24h】

Factors influencing the microbial mineralization of polycyclic aromatic hydrocarbons in coastal marine sediments.

机译：影响沿海海洋沉积物中多环芳烃微生物矿化的因素。

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

Microbial mineralization of polycylic aromatic hydrocarbons (PAHs) in Long Island Sound sediments was examined to better understand how environmental processes that cause changes in redox conditions will influence mineralization rates.; Sediment resuspension into overlying oxic water increased both the rate and the total fraction of PAH mineralized for 3 PAHs measured in experimental sediment water microcosms. Subsequent desorption experiments indicated that slower than predicted mineralization of naphthalene may be due to greater resistance to desorption of naphthalene from sediment matrices and may result in sub-equilibrium porewater concentrations. First order rate constants normalized to either aqueous concentrations in whole microcosms and those predicted for porewaters were within the same order of magnitude for all three compounds, suggesting that availability is an important control on mineralization and that all three PAHs may be similarly labile in the aqueous phase.; In thin sediment plugs, microbial mineralization of both 14C-phenanthrene and 14C-naphthalene again Strongly correlated with exposure to oxygen. First order rate constants under continuously oxic conditions were 0.049 d−1 for phenanthrene and 0.24 d−1 for naphthalene. Modeled rate constants based upon total fraction of time under oxic and anoxic conditions and rates taken from end-member sediment plugs correlated well with measured rate constants for oscillating treatments.; Partitioning of phenanthrene and naphthalene between sediments and porewater in plug experiments varied under different redox conditions. For both compounds, increased exposure to anoxic conditions decreased the fraction of PAHs found in porewater, which could be partially responsible for lower mineralization rates under anaerobic conditions since porewater PAH is generally accepted to be the bioavailable pool. Partitioning of phenanthrene was typically within the range predicted by equililibrium partitioning whereas partitioning of naphthalene into the sediment porewater was less than what would be predicted by equilibrium partitioning.; Addition of freshly killed phytoplankton stimulated overall bacterial activity in sediment seawater slurries this increased enzymatic activity correlated With increased mineralization of 14C-phenanthrene in carbon amended sediments compared to non-amended sediments. Calculations indicate that inputs of labile carbon resulting from redox oscillation could be quantitatively similar to those associated with phytoplankton blooms and were on the same order as amendments in these experiments. (Abstract shortened by UMI.)
机译：检验了长岛海湾沉积物中多环芳烃的微生物矿化作用，以更好地理解引起氧化还原条件变化的环境过程如何影响矿化速率。在实验性沉积物水的微观世界中测得，沉积物重悬到上层含氧水中可以提高3种PAH矿化的PAH的速率和总比例。随后的解吸实验表明，萘的矿化速度比预期的慢，可能是由于对沉积物基体中的萘解吸附的抵抗力增强，并且可能导致亚平衡孔隙水浓度升高。一阶速率常数已标准化为整个微观环境中的任一水溶液浓度，而对于孔隙水所预测的那些速率常数，在所有三种化合物中均处于同一数量级，这表明可用性是矿化的重要控制因素，并且所有三种PAH在水溶液中的稳定性均相似相。;在稀薄的沉积物堵塞物中， 14 C-菲和 14 C-萘的微生物矿化再次与暴露于氧气密切相关。在连续含氧条件下，菲的一阶速率常数对菲为0.049 d -1 ，对萘为0.24 d -1 。基于在有氧和无氧条件下的总时间比例以及从端部成员沉积物塞中获取的速率，所建模的速率常数与用于振动处理的测得速率常数相关性很好。在堵塞实验中，菲和萘在沉积物和孔隙水之间的分配在不同的氧化还原条件下有所不同。对于这两种化合物，增加的缺氧条件暴露会减少在孔隙水中发现的PAHs的比例，这可能是造成厌氧条件下矿化速率降低的部分原因，因为孔隙水PAH通常被认为是生物可利用的池。菲的分配通常在平衡分配所预测的范围内，而萘在沉积物孔隙水中的分配要小于平衡分配所预测的范围。与未修正的沉积物相比，新近杀死的浮游植物的添加刺激了沉积物海水浆液中的总体细菌活性，这种酶活性的增加与碳修正沉积物中 14 C菲的矿化增加有关。计算表明，氧化还原振荡产生的不稳定碳的输入量在数量上与浮游植物水华相关，并且与这些实验中的修正量相同。 （摘要由UMI缩短。）

著录项

  • 作者

    Gulnick, Jeanne Debra.;

  • 作者单位

    State University of New York at Stony Brook.;

  • 授予单位 State University of New York at Stony Brook.;
  • 学科 Biology Oceanography.; Geochemistry.
  • 学位 Ph.D.
  • 年度 2000
  • 页码 188 p.
  • 总页数 188
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 海洋生物;地质学;
  • 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