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首页> 外文学位 >Particle-related biogeochemical cycles of hydrophobic organic contaminants in estuarine waters.
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Particle-related biogeochemical cycles of hydrophobic organic contaminants in estuarine waters.

机译：河口水域中疏水性有机污染物的颗粒相关生物地球化学循环。

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摘要

The distributions of hydrophobic organic contaminants (HOCs), including polycyclic aromatic hydrocarbon (PAHs) and polychlorinated biphenyls (PCBs), in different sizes of suspended particles, in settling particles, in sediments, and in the dissolved phase were studied in the Chesapeake Bay. Samples were collected from the water column at a depth of 3 m and from 2 m above the bottom at the HI buoy station in the mesohaline Chesapeake Bay from October 1990 to August 1992. Since PCBs and PAHs strongly associate with natural particles, estuarine particle dynamics resulting in especially high concentrations of suspended particles play a critically important role in the transport of HOCs.;Elevated concentrations of HOCs (up to 500 ng/g of total PCB and ;In the Chesapeake Bay, particulate HOCs are mainly transported by settling of suspended particles and by resuspension of surficial sediments. Resuspension fluxes of HOCs, up to 5 ;The sorption kinetics of PCBs to the Chrysophyte Isochrysis galbana and a model submicron particle were found to follow a two-step mechanism in a laboratory study. The overall extent of PCB sorption was determined by the second step of the sorption, since the rapid first step reached "pseudo-equilibrium" in a few minutes. The second step mass transfer coefficients of PCB congeners to cultured phytoplankton were constant (0.02 cm/hr) after 15 minutes and about 5 times lower than those to submicron particles. By using the laboratory measured mass transfer coefficients of PCBs, the phytoplankton in the mesohaline Chesapeake Bay were estimated to have been exposed to PCB congeners for 6-15 days. Sorption of PCBs to suspended particles in the water column of the Chesapeake Bay are far away from a simple linear two-phase sorptive equilibrium. The high variation in PCB distribution coefficients in phytoplankton of the Chesapeake Bay may be adequately interpreted by a kinetic three-phase sorption model.
机译：在切萨皮克湾研究了不同大小的悬浮颗粒，沉降颗粒，沉积物和溶解相中包括多环芳烃（PAHs）和多氯联苯（PCBs）在内的疏水性有机污染物（HOC）的分布。从1990年10月至1992年8月，在中盐水切萨皮克湾HI浮标站的水柱深度3 m和底部上方2 m处采集样品。由于PCBs和PAHs与天然颗粒强烈相关，因此河口颗粒动力学导致特别高浓度的悬浮颗粒在HOC的运输中起着至关重要的作用。; HOC的浓度升高（高达500 ng / g的PCB总量;在切萨皮克湾，颗粒状的HOC主要通过沉降悬浮物来运输在实验室研究中，HOCs的重悬通量高达5；多氯联苯对金眼鱼等离子和模型亚微米颗粒的吸附动力学遵循两步机理。 PCB的吸附是由吸附的第二步确定的，因为快速的第一步在几分钟内就达到了“伪平衡”。 15分钟后，PCB同源物对浮游植物的系数保持恒定（0.02 cm / hr），比亚微米微粒的系数低约5倍。通过使用实验室测量的多氯联苯的传质系数，估计中卤化切萨皮克湾的浮游植物已暴露于多氯联苯同源物6-15天。切萨皮克湾水柱中多氯联苯对悬浮颗粒的吸附远离简单的线性两相吸附平衡。切萨皮克湾浮游植物中PCB分布系数的高变化可以通过动力学三相吸附模型充分解释。

著录项

  • 作者

    Ko, Fung-Chi.;

  • 作者单位

    University of Maryland, College Park.;

  • 授予单位 University of Maryland, College Park.;
  • 学科 Biogeochemistry.;Environmental science.;Ocean engineering.
  • 学位 Ph.D.
  • 年度 1994
  • 页码 217 p.
  • 总页数 217
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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