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首页> 外文学位 >Bioavailability and bioaccumulation of sediment-associated, desorption-resistant fraction of polycyclic aromatic hydrocarbon contaminants.
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Bioavailability and bioaccumulation of sediment-associated, desorption-resistant fraction of polycyclic aromatic hydrocarbon contaminants.

机译：多环芳烃污染物的沉积物相关的，抗解吸组分的生物利用度和生物富集。

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摘要

This study is directed toward identifying and characterizing the bioavailability of both reversibly sorbed and desorption-resistant fraction of hydrophobic organic contaminants in natural biologically active sediments and the corresponding consequences to prediction, control and regulation of these contaminants. The focus is on polycyclic aromatic hydrocarbons (PAHs) with particular emphasis on phenanthrene and benzo[a]pyrene. A quantity of well-characterized and extensively desorbed sediments was prepared by desorbing the lab-inoculated sediment with an isopropanol and electrolyte solution. This procedure was proved to be a very effective method to prepare sediments containing contaminants largely limited to a desorption-resistant compartment. Accumulation of contaminants in the tubificid, Ilyodrilus templetoni, was measured after exposure to the prepared sediments. The uptake route of sediment-associated phenanthrene and benzo[a]pyrene and the effect of sediment ingestion and digestion by deposit feeders on the release of the contaminants from ingested sediment particles was also investigated.; Desorption-resistant or sequestered fraction of phenanthrene was available to Ilyodrilus templetoni but with reduced availability compared to reversibly sorbed phenanthrene. The reduction in bioavailability was approximately proportional to the increase in sediment-water partition coefficient. Strong correlation of bioavailability with effective partition coefficient was also observed for benzo[a]pyrene. The results of this study demonstrated that sediment pore water concentration defines steady state accumulation of PAHs in the deposit-feeding oligochaete, regardless of the route of uptake (via sediment ingestion or absorption from water). Therefore, bioavailability of desorption-resistant fraction of contaminant is reduced in direct proportion to the reduction in pore water concentration as measured by physico-chemical means (i.e. abiotic). Since steady state accumulation for these compounds in the deposit feeders is controlled by pore water concentration, extraction by gut fluids as proposed by some authors does not indicate bioavailability for the contaminants and organisms employed in this study. These conclusions would be complicated by metabolic processes that might occur with other compounds or in other organisms that would introduce fate processes other than simple partitioning.
机译：这项研究旨在鉴定和表征天然生物活性沉积物中疏水性有机污染物的可逆吸附和抗解吸组分的生物利用度，以及对这些污染物的预测，控制和调节的相应后果。重点是多环芳烃（PAHs），特别是菲和苯并[a] re。通过用异丙醇和电解质溶液解吸实验室接种的沉积物，可以制备出大量具有良好特征的且大量解吸的沉积物。事实证明，该程序是制备含污染物的沉积物的非常有效的方法，该污染物在很大程度上仅限于抗脱附室。暴露于准备好的沉积物中后，测量微管虫（Ilyodrilus templetoni）中污染物的积累。还研究了与沉积物有关的菲和苯并[a]的吸收途径，以及沉积物进料器对沉积物的摄取和消化对从被摄取的沉积物颗粒中释放污染物的影响。耐解吸或隔离的菲部分可用于坦波利斯伊利诺德（Ilyodrilus templetoni），但与可逆吸附的菲相比，其可用性降低。生物利用度的降低大约与沉积物-水分配系数的增加成正比。苯并[a] py也观察到了生物利用度与有效分配系数的强烈相关性。这项研究的结果表明，沉积物的孔隙水浓度决定了沉积物中的低聚多环芳烃的稳态积累，而与吸收途径无关（通过沉积物的摄入或从水中吸收）。因此，污染物的抗解吸部分的生物利用度与通过理化手段（即非生物）测量的孔隙水浓度的降低成正比地降低。由于这些化合物在沉积物进料器中的稳态积累受孔隙水浓度的控制，因此一些作者提出的通过肠液进行提取并不表明该研究中所采用的污染物和生物的生物利用度。这些结论可能会因其他化合物或其他生物体内可能发生的代谢过程而变得复杂，这些代谢过程会引入除简单分配以外的命运过程。

著录项

  • 作者

    Lu, Xiaoxia.;

  • 作者单位

    Louisiana State University and Agricultural & Mechanical College.;

  • 授予单位 Louisiana State University and Agricultural & Mechanical College.;
  • 学科 Engineering Chemical.; Engineering Environmental.
  • 学位 Ph.D.
  • 年度 2003
  • 页码 162 p.
  • 总页数 162
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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