水溶液中氟的吸附平衡模型研究进展

Equilibrium Model Studies in Adsorption of Fluoride in Aqueous Solution:A Summary of Recent Researches

氟是人体必需的微量元素,但高浓度含氟废水对人体和环境会造成很大危害。吸附法是目前最常用的除氟方法,新型吸附材料也成为世界研究热点。吸附平衡模型广泛地应用于水中氟的吸附过程表征,研究这些模型对揭示吸附机理、设计除氟工艺和选择合适的吸附材料具有重要意义。对国内外水中氟吸附的平衡模型及其应用实例综述,其中最常用的是Langmuir和Freundlich平衡模型。由于各种模型都有其各自的优缺点和适用范围,单独使用某一种吸附模型不能精确地表征吸附剂对溶液中氟的吸附作用。今后应从具体的吸附作用机理角度改进氟的吸附平衡模型,或综合采用多种模型来分阶段表征氟的吸附过程,并且建立模型参数之间的联系,提高模型在实际应用中对选择合适吸附材料和最佳吸附工艺条件的指导作用。

Fluoride is the essential element of human,but large amount of fluoride in wastewater will result in huge damage to human and environment.Adsorptive methods are the most common means to remove fluoride from wastewater,and new adsorptive materials have become hot spots of defluoridation research.Various equilibrium models are of extensive use in characterization of aqueous fluoride adsorption,intending to discover the adsorption mechanism,design the defluoride technique and select proper material.The purpose of this paper is to summarize fluoride adsorption equilibrium models and practical examples,among which Langmuir and Freundlich models are the most widely used.Due to advantages,disadvantages and application scope inherent in each equilibrium model,single model cannot precisely characterize fluoride adsorption.And the improvement of adsorption models in terms of specific adsorptive mechanisms,the comprehensive use of adsorption models characterizing fluoride adsorption process in stages,the establishment of relations between model parameters,and the practical application of adsorption models in the selection of proper materials and optimal operation parameters are the trends of later researches.