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首页> 外文学位 >Thermodynamics and kinetics of complexation of copper with natural humic substances and suspended particulate matter.
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Thermodynamics and kinetics of complexation of copper with natural humic substances and suspended particulate matter.

机译：铜与天然腐殖质和悬浮颗粒物络合的热力学和动力学。

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摘要

Thermodynamics and kinetics of copper complexation by Aldrich humic acid (HA) and dissolved organic matter (DOM) from several natural waters were studied. Toxicity tests used HA and Suwannee River DOM. Fractionated dissolved organic matter (DOM) from natural waters and the effluent of wastewater were characterized.; A two-site-discrete-ligand model describing copper complexation by HA or DOM is first-order in dissolved organic carbon (DOC) for 5–15 mg C/L. Increasing ionic strength or decreasing pH greatly increases Cu 2+ activity. Hardness has little effect at low concentration. Alkaline earth and copper compete for some binding sites. Cu-humate complex formation is rapid only in Ca-free solutions. A two-site kinetic model with pseudo-first-order rate constants was developed. Surface complexation of Cu by suspended solids was also modeled. Copper's reaction with suspended particles is faster than with the filtrate.; Copper toxicity to Ceriodaphnia dubia was determined in flow-through bioassays to investigate the effect of reaction kinetics. Cu toxicity decreases with increasing reaction time and humate concentration. Toxicity and Cu2+ concentration correlated, independent of humate concentration and reaction time, consistent with the free-ion activity model (FIAM). The chemical kinetic model, combined with bioassay system hydraulics, predicted Cu toxicity in the presence of HA or DOM. In the presence of solids, toxicity is the same for 6 and 24-h reaction times, indicating rapid equilibration. Correlation between survival and [Cu2+] also supports the FIAM, but deviation from results for bioassays of DOC is probably due to other effects of particles on the organisms.; Isolated humic acid (HA), fulvic acid (FA) and the hydrophilic fraction (HyI) were characterized by elemental analysis, 1H NMR spectrometry, proton and copper binding, and copper complexation kinetics. HA and FA from the four wetland waters have similar NMR spectra, total acidity and H/C ratios, corresponding to those in the literature. Aliphatic functional group contents follow HA FA HyI. Copper binding ability follows the carboxyl content: HyI FA HA. Copper complexation kinetics of HA and FA fractions of Suwannee River DOM are similar, but the rate with HyI is faster, implying that Cu reacts with weaker ligands faster than with stronger Cu-binding ligands.
机译：研究了几种天然水中Aldrich腐殖酸（HA）和可溶性有机物（DOM）络合铜的热力学和动力学。毒性测试使用HA和Suwannee河DOM。表征了自然水中分馏的溶解有机物（DOM）和废水的排放。描述HA或DOM引起的铜络合的两点离散配体模型在溶解有机碳（DOC）中浓度为5-15 mg C / L时是一阶的。离子强度的增加或pH值的降低都大大增加了Cu 2 + 的活性。在低浓度下硬度几乎没有影响。碱土和铜竞争一些结合位点。仅在无钙溶液中，腐殖酸铜络合物的形成迅速。建立了具有伪一阶速率常数的两点动力学模型。还模拟了铜通过悬浮固体的表面络合。铜与悬浮颗粒的反应比与滤液的反应快。在流通式生物测定中确定了铜对 dubia 的毒性，以研究反应动力学的影响。铜的毒性随着反应时间和腐殖酸盐浓度的增加而降低。毒性与Cu 2 + 浓度相关，与腐殖酸盐浓度和反应时间无关，与自由离子活性模型（FIAM）一致。化学动力学模型与生物测定系统的液压系统相结合，可预测在HA或DOM存在下的Cu毒性。在固体存在下，毒性在6和24小时的反应时间内是相同的，表明迅速达到平衡。存活率与[Cu 2 + ]之间的相关性也支持FIAM，但是DOC生物学检测结果的偏离可能是由于颗粒对生物的其他影响。通过元素分析， 1 H NMR光谱，质子与铜的结合以及铜的络合动力学，对分离出的腐殖酸（HA），富里酸（FA）和亲水级分（HyI）进行了表征。来自四个湿地水域的HA和FA具有相似的NMR谱，总酸度和H / C比，与文献中的相对应。脂肪族官能团含量遵循HA

著录项

  • 作者

    Ma, Huizhong.;

  • 作者单位

    University of Delaware.;

  • 授予单位 University of Delaware.;
  • 学科 Engineering Environmental.; Environmental Sciences.
  • 学位 Ph.D.
  • 年度 1999
  • 页码 327 p.
  • 总页数 327
  • 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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