疏水性有机污染物的非线性吸附过程及滞后现象的研究

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	疏水性有机污染物的非线性吸附过程及滞后现象的研究
其他题名	Sorption and desorption of hydrophobic organic contaminants: nonlinearity and hysteresis
	梁重山
	2002
学位授予单位	中国科学院地球化学研究所
学位授予地点	中国科学院地球化学研究所
学位名称	博士
学位专业	地球化学
关键词	疏水性有机污染物非线性吸附过程 Freundlich模型双区位反应模型
摘要	该论文测定了疏水性有机污染物在地质吸附剂上的吸附-解吸等温线,选用合适的模型拟合了这些等温线,并且研究了非线性吸附过程、解吸滞后现象与壤/沉积物异质性之间的关系;得到以下几点认识:1、利用红外光谱仪和核磁共振谱仪研究了土壤/沉积物有机质、土壤胡敏酸的组成.2、测定了菲、蔡、1,3,5-三氯苯在土壤/沉积物及处理样品上的吸附等温线.所有地质吸附剂上的吸附等温线表现出明显的非线性.Freundlic上模型能很好的拟合了有机物的吸附等温线,双区位反应模型(DRDM)能很好的拟合有机物在部分土壤/沉积物及处理样品上的吸附等温线,并且DRDM模型清楚的反映出有机物在低浓度和高浓度下不同的吸附特征.3、对相同土壤/沉积物样品,萘的吸附等温线要比菲的吸附等温线的线性要好些,这与它们的物化性质有关.4、对碱提取后残留土壤测定了菲、茶、1,3,5-三氯苯的吸附-解吸等温线.5、菲和萘在土壤/沉积物及处理样品上的吸附-解吸过程存在明显的滞后现象.
其他摘要	Sorption-desoprtion to natural soil/sediment is an underlying process affecting the transport, degradation, and biological activity of hydrophobic organic contaminants (HOCs) in the environment. Mineral fractions and natural organic matters (NOM) in soil/sediment play important roles in determining the sorption and desorpion patterns of hydrophobic organic contaminants. For these contaminants, the mineral fractions of soil/sediment play minor roles than NOM. Much recent work has revealed that content and nature of organic matter have a significant impact on sorption capacity and nonlinearity. This dissertation describes an experimental pursuit of a mechanistic model for interpreting and quantitatively describing nonlinear, slow, and hysteretic sorption phenomena associated with heterogeneous soils and sediment in subsurface systems. The main conclusions have been summarized as follows: 1 N The soil/sediment organic matter and humic acid were characterized using carbons types derived from IR and 13C CPMAS NMR spectroscopy. Studies have demonstrated that soil/sediment organic matters contain a large proportion of alkyl C ( -78% ) which appears to contribute more than aromatic C (-17%), and Carbonyl C (-4.5 %) contributed the smallest proportion to the soil/sediment organic matters. Humic acids contain a larger proportion of aromatic C (-28%) than soil/sediment organic matters. Humic acids contain a proportion of alkyl C varied 60 %, which were slightly enriched in Carbonyl C and O-alkyl C. 2. Completely mixed batch reactor systems were utilized to measure phenanthrene, naphthalene, 1, 3, 5 - trichlorobenzene sorption for 5 natural, soils and sediment, 10 oxidized samples, 6 base extracted samples, 6 humic acids. Sorption isotherms for all samples are nonlinear. All sets of equilibrium sorption data were fitted using three different sorption model: the linear model, the Freundlich model or its linearized form, and the dual reactive domain model (DRDM). The linear model was not appropriate for describing any of the experimental sorption data; only the Freundlich model was found to be adequate for all samples; the dual reactive domain model was adequate for partly samples. 3N In all soils and sediments, sorption isotherms for naphthalene are significantly more linear than those for phenanthrene, which is related to the property of two sorbates. Solubility for phenanthrene is 1.12 mg/L, and logi^olv is 4.57, 31.5 mg/L, 3.30 for naphthalene respectively, so phenanthrene is a more hydrophobic organic solute than naphthalene. As a result, the more hydrophobic is organic solutes, the more nonlinear is the sorption isotherm, and the greater is the sorption affinity of the soil and sediment hydrophobic solutes. 4 6 base extracted samples were measured phenanthrene, naphthalene, 1, 3, 5 -trichlorobenzene sorption isotherms. The base extracted samples exhibit significantly higher sorption capacities and more nonlinear than these untreated samples, wliich suggest that the presence of small amounts of humin and some special carbon materials may be responsible for the observed nonlinear sorption. 5. The apparent sorption-desorption hystersis was quantified for each samples. Sorption-desorption hystersis each vary from sample to sample, they also appear to correlate with the chemical characteristics of soil organic matter. The more condensed is the soil organic matter, the more geologically old is the soil organic matter, and the more apparent is the sorption-desoprtion hystersis. On the other hand, the pore structure of soils may be a critical factor in sorption-desorption hystersis of hydrophobic organic contaminants.
页数	125
语种	中文
文献类型	学位论文
条目标识符	http://ir.gyig.ac.cn/handle/352002/3622
专题	研究生_研究生_学位论文环境地球化学国家重点实验室
推荐引用方式 GB/T 7714	梁重山. 疏水性有机污染物的非线性吸附过程及滞后现象的研究[D]. 中国科学院地球化学研究所. 中国科学院地球化学研究所,2002.

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