DOM对有机氯农药在土壤—地下水中的迁移影响研究

发布时间：2018-06-13 20:56

本文选题：有机氯农药 + 溶解性有机质　；参考：《武汉科技大学》2015年硕士论文

【摘要】：有机氯农药在土壤包气带中随土壤间隙水不断向下运移是其造成地下水污染的主要途径。溶解性有机质(DOM)通过影响有机氯农药在土壤中的溶解、吸附等环境行为，进而影响其迁移性。本文旨在研究溶解性有机质对有机氯农药在土壤-地下水间迁移的影响，通过等温吸附实验和土柱淋溶实验来完成这项研究。不同来源的DOM因具有不同的组分，性质各异，对有机氯农药的迁移影响不同。为深入揭示其影响机制，采用紫外-可见光谱技术和三维荧光光谱技术联合使用的方法对其化学结构进行了表征，并推测其可能表现的性质。结果表明，在等温吸附实验中，土壤内源DOM会抑制有机氯农药在土壤中的吸附，而添加20mg·L-1外源DOM却可明显促进有机氯农药在S5号土壤中的吸附，其中，淤泥DOM对有机氯农药的吸附促进作用更为强烈。在一定范围内，有机氯农药在土壤中的吸附量不随外源DOM浓度的改变而改变。所有的吸附曲线均可用线性模型很好的拟合，有机氯农药受DOM影响在土壤中的吸附表现为在土壤和水溶液之间的分配。在土柱淋溶实验中，总体来看，HCHs类有机氯农药相比DDTs类在土壤中表现出更强的迁移性。受蒸馏水和淤泥DOM溶液淋溶的土柱，渗滤液中有机氯农药的含量很低，均不超过3ng·L-1，而受营养土DOM溶液淋溶的土柱，渗滤液中HCHs类有机氯农药的含量较高，变化范围为3.79ng·L-1~102.36ng·L-1。另外，和采用蒸馏水淋溶的土柱相比，使用淤泥DOM和营养土DOM淋溶后，可促进有机氯农药向土壤深处迁移，其中，营养土DOM对其促进作用更大。
[Abstract]:The migration of organochlorine pesticides (OCPs) in soil aeration zone with soil interstitial water is the main way to cause groundwater pollution. Dissolved organic matter (DOM) affects the migration of organochlorine pesticides (OCPs) by affecting the environmental behaviors such as dissolution and adsorption of organochlorine pesticides in soil. The purpose of this paper is to study the effect of dissolved organic matter on the migration of organochlorine pesticides between soil and groundwater. Due to their different components and properties, Dom from different sources has different effects on the migration of organochlorine pesticides (OCPs). In order to reveal its influence mechanism, the chemical structure was characterized by the combination of UV-Vis spectroscopy and three-dimensional fluorescence spectroscopy, and its possible properties were speculated. The results showed that, in the isothermal adsorption experiment, the adsorption of organochlorine pesticides in soil was inhibited by internal Dom, but the adsorption of organochlorine pesticides in S5 soil was promoted by adding exogenous Dom of 20mg L-1. Dom enhanced the adsorption of organochlorine pesticides more strongly. In a certain range, the adsorption amount of organochlorine pesticides in soil does not change with the change of exogenous Dom concentration. All the adsorption curves can be fitted well by linear model. The adsorption of organochlorine pesticides under the influence of Dom in soil shows the distribution between soil and aqueous solution. In the soil column leaching experiment, HCHs organochlorine pesticides showed stronger migration in soil than DDTs. The content of organochlorine pesticides (OCPs) in leachate of distilled water and mud Dom solution was very low, which was not higher than that of 3ng L -1, while the content of HCHS organochlorine pesticides in leachate was higher than that in soil column eluted by Dom solution of nutritious soil. The range of variation was 102.36 ng / L of 3.79ng L-1. In addition, compared with soil column eluted by distilled water, Dom from silt and nutrient soil can promote the migration of organochlorine pesticides to the deep soil, and Dom of nutrient soil can promote the migration of organochlorine pesticides to the deep soil.
【学位授予单位】：武汉科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X592

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