氟在土—水系统中的迁移机理与含氟水的处理研究

【作者】 董岁明；

【导师】 李佩成；

【作者基本信息】 长安大学 ， 地质工程， 2004， 博士

【摘要】 本文以对环境和人类健康产生巨大影响的物质之一氟为主要研究对象，选择人类赖以生存的土—水系统为研究环境，采用静态和动态相结合的实验方法，理论分析和实验验证相统一的技术路线，从实验和理论两个方面系统地研究了氟在土—水系统中迁移转化、形态变化、固液相之间物质交换模式、分布特征等规律，揭示了氟在土壤剖面上的分布特征；发现了亚粘土和粉质亚砂土的氟吸附量、形态变化和吸附模式变化之间的关系和变化规律，以及环境体系的pH和Eh与固液相物质交换量之间的关系。探讨了控制氟迁移转化的主要物理化学作用及其影响因素，研究表明，溶解与沉淀的相间转移和吸附是氟在土—水系统中迁移转化的主要模式，在非饱和状态下，CaF₂和CaCO₃的溶解与沉淀反应是制约氟在土水系统中迁移和转化的重要作用，氟与铁铝等的络合反应、含氟矿物的性质和种类（含氟量、溶解性等）、溶液的pH等对氟的迁移转化也会产生重要影响，并初步确定了土壤中吸附与沉淀反应的主导控制溶液氟浓度的界限（液相氟的浓度），约为10^-6（pH=8.5）至10^-2mol／L（pH=4.5）。提出并从理论上分析和论证了基于离子交换与吸附原理的配体交换固液分离的饮水脱氟方法，并基此原理制备了两种高效脱氟剂，脱氟剂的条件实验结果表明：Fe（Ⅲ）-Y沸石脱氟剂的脱氟容量可达29mg／g以上，Fe（Ⅲ）-R树脂的脱氟容量可达14mg/g以上，两种脱氟剂对氟有很高的选择性且不产生二次污染，可重复再生利用。综合实验结果提出了两种脱氟剂可能的脱氟、洗脱和再生机理，建立并验证了离子交换与吸附脱氟过程的动力学模型，研究结果为深化脱氟研究奠定了一定的理论基础。更多还原

【Abstract】 Behavior characteristics of the fluorin, which is one of the substances caused great affect for environment and human health in the soil and water system, togather with its controling factors are studied with combining a methodolody the static state experiments with dynamic state experiments, the fluorine ion of the soil and water system moves and changes the transforms , the form changes, the substance interchanges pattern and feature and mechanism between the liquid phase and solid phase are researched. Mechanism of distribution characteristics of fluorine in soil profile and in the crops are revealed. The relationship between soil fluorine content or speciation variation of fluorine or adsorption forms in the soil and water system, and between variations of pH and Eh of soil solution and the unsaturated character of soil moisture along soil adsorbing fluorine from soil solution, are found by the writer. the relationship between the dissolution and the precipitation of CaCO3 or CaF2 controlls the concentration of fluorine in soil, but the relationship between the adsorption and pH of soil solution controlls the concentration under that the soil solution concentration of fluorine less than its critical concentration of the precipitation , The dominantly control the concentration of soil solution, are preliminarily established, that is about 10-6 (pH=8.5) ~10-2mol/L (Ph=4.5). The methods of Removing fluorine ion are put forward based on ion exchange and adsorption principle , separated the liquid and solid phase, Moreover two kinds of new defluoridation material are prepared, the Experiment shows that both of the defluoridation material have a high defluoridation capability, with activated Fe(III)-R resin being 14mg/g and Fe(III)-Y zeolite molecular sieve being more than 29mg/g , The two kind of new defluoridation materials have high choice for fluorine, their defluoridation effect are good by more eluting and regenerating. combining experiment results, mechanism of the two kind of new defluoridation material is discussed. Established and validated the mathematical former of defluoridation process of two kinds of defluoridation materials , the resultes settled theoretic fundation for embedded defluoridation reseach.更多还原