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Sorption and biodegradation of ionizable polycyclic aromatic hydrocarbons (IPAHs) in estuarine sediment.

机译：河口沉积物中可电离的多环芳烃（IPAH）的吸附和生物降解。

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摘要

In the first part of this research, adsorption of quinoline (pK a = 4.92) and background electrolyte (CaCl2) onto specimen kaolinite and montmorillonite were measured as a function of pH (3-7.5) and ionic strength (1-10 mM), and as a function of quinoline concentration (0.02-1.55 mM) at fixed pH values of maximum adsorption. Maximum sorption of quinoline occurred at pH 3.5-4.0 for kaolinite, and pH 3.0-5.0 for montmorillonite. At their respective pH values of maximum adsorption, the sorption capacity for quinoline was 100 times greater with montmorillonite than kaolinite on mass basis. Selectivity coefficients, which were calculated from pH edge data, indicated selectivity for cationic quinoline (QH+) over Ca 2+ was greater with montmorillonite (Kexc = 27 at pH 4) compared to kaolinite (Kexc = 1.6 at pH 4), and Kexc was not affected by ionic strength for either clay. The results indicate the important role of charged siloxane sites in the adsorption of this N-heterocyclic contaminant.; In the second part of this research, sorption and biodegradation of structurally similar compounds of ionizable polycyclic aromatic hydrocarbons (IPAHs) in an estuarine sediment were studied. The sorption of 16 IPAHs to the sediment was measured in synthetic estuarine water as a function of IPAH concentration (1-100 muM) at fixed ionic strength (0.4 M), pH (7.6+/-0.2), and sediment concentration (0.371 g C kg-1 suspension) after a 24 h equilibration period.; Biodegradation experiments with 20 IPAHs (naphthalene-based and quinoline-based structures) were initially conducted with two pure cultures in order to select the most metabolically capable organism. The two cultures included Neptunomonas naphthovorans (ATCC 700638), isolated from PAH-contaminated sediment in Puget Sound, WA, and unidentified NP-1, isolated from municipal wastewater in State College, PA. The initial "screening" experiments revealed that N. naphthovorans could biodegrade 11 of the 20 IPAHs, while NP-1 could biodegrade 9 of the 20 IPAHs. Therefore, all further experiments were conducted with N. naphthovorans. Experiments were conducted in synthetic estuarine water in the absence and presence of estuarine sediment (0.371 g C kg-1 suspension) at a constant initial IPAH concentration of 32 muM, at fixed ionic strength (0.4 M) and pH (7.6+/-0.2). Biodegradation kinetics for all 11 IPAHs were not universally well fit to a simple reaction-order model (e.g., zero-order or first-order), therefore, the percent final extent of biodegradation after 5 days (%FE; where high %FE corresponds to greater degradation) was used to compare biodegradability among the IPAHs, and to develop predictive QSARs. The predictive QSARs showed that log %FE of IPAHs (naphthalene-based structure) exhibited poor positive correlations with log Sw and log Kow, negative correlation with pKa1 ; and no correlation with 1chi. The presence of sediment resulted in reduced final extent of 3-hydroxy-7-methyl-2-naphthoic acid, 4-fluoro-2-naphthoic acid, quinoline, and quinoxaline but no effects on the final extent of 1-hydroxy-2-naphthoic acid, 1,8-naphthaldehydic acid, and 6-amino-2-naphthoic acid. A log K oc' -log %FE (naphthalene-based structure) showed positive correlation. (Abstract shortened by UMI.)
机译：在这项研究的第一部分中，测量了喹啉（pKa = 4.92）和背景电解质（CaCl2）在标本高岭石和蒙脱石上的吸附随pH（3-7.5）和离子强度（1-10 mM）的变化，在最大吸附的固定pH值下，作为喹啉浓度（0.02-1.55 mM）的函数。高岭石的pH 3.5-4.0和蒙脱石的pH 3.0-5.0发生了喹啉的最大吸附。在它们各自的最大吸附pH值下，基于质量，蒙脱石对喹啉的吸附能力比高岭石大100倍。由pH边缘数据计算得出的选择性系数表明，与高岭石（Kexc = 1.6，pH 4）相比，蒙脱石（Kexc = 27，pH 4）对Ca 2+的阳离子喹啉（QH +）的选择性更大。不受任何一种粘土的离子强度的影响。结果表明带电荷的硅氧烷位点在该N-杂环污染物的吸附中起重要作用。在本研究的第二部分中，研究了在河口沉积物中对结构相似的可电离的多环芳烃（IPAH）化合物的吸附和生物降解。在固定的离子强度（0.4 M），pH（7.6 +/- 0.2）和沉淀物浓度（0.371 g）下，在合成河口水中测量了16种IPAHs对沉淀物的吸附与IPAH浓度（1-100μM）的关系。 24小时的平衡期后； C kg-1悬浮液。最初使用两种纯培养物进行了20种IPAH（萘基和喹啉基结构）的生物降解实验，以选择代谢能力最强的生物。两种文化分别是从华盛顿州普吉特海湾的受PAH污染的沉积物中分离出的纳豆单孢菌（ATCC 700638），以及从宾夕法尼亚州立大学的市政废水中分离出的未鉴定的NP-1。最初的“筛选”实验表明，萘甲丙酸奈瑟菌可以生物降解20个IPAH中的11个，而NP-1可以生物降解20个IPAH中的9个。因此，所有进一步的实验都是用萘甲酸猪笼草进行的。在固定的离子强度（0.4 M）和pH（7.6 +/- 0.2）下，在不存在和存在河口沉积物（0.371 g C kg-1悬浮液）的情况下，在合成河口水中进行实验，恒定IPAH初始浓度为32μM。 ）。并非所有11种IPAH的生物降解动力学都普遍适用于简单的反应阶模型（例如，零阶或一阶），因此，5天后的最终生物降解百分数（％FE；其中％FE高） （以更高的降解率）用来比较IPAH之间的生物降解能力，并建立预测性QSAR。预测性QSARs显示IPAHs（萘基结构）的log％FE与log Sw和log Kow呈弱正相关，与pKa1呈负相关。与1chi无关。沉积物的存在导致3-羟基-7-甲基-2-萘甲酸，4-氟-2-萘甲酸，喹啉和喹喔啉的最终程度降低，但对1-羟基-2-的最终程度没有影响萘甲酸，1,8-萘二甲酸和6-氨基-2-萘甲酸。 log K oc'-log％FE（基于萘的结构）显示正相关。 （摘要由UMI缩短。）

著录项

  • 作者

    Pisutpaisal, Nipon.;

  • 作者单位

    The Pennsylvania State University.;

  • 授予单位 The Pennsylvania State University.;
  • 学科 Engineering Environmental.; Environmental Sciences.
  • 学位 Ph.D.
  • 年度 2003
  • 页码 229 p.
  • 总页数 229
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 环境污染及其防治;环境科学基础理论;
  • 关键词

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