表面羟基化的碳羟基磷灰石在高氟水处理中的应用研究

According to the Chinese national sanitary standards for the limit of fluoride concentration in drinking water (1.0 mg/L), nearly 260 million people are consuming excess fluoride-containing water in China. So it is necessary to control the amount of fluoride in drinking water. Eggshell has developed porosity, high reactivity and pure CaCO3 as an important constituent. Low molecular weight organic acids(LMWOAs) possessing one or more carboxyl and hydroxyl groups can complexes with adsorbents in soultion or soil; Moreover, the formation of complexes between organic acids/anions and metal ions of the adsorbents surface could decrease the activation energy of surface reaction and enhance the materials adsorption ability and reactivity. However little knowledge is available about the adsorption of fluoride on eggshell. Information concerning the adsorption mechanisms of LMWOAs onto carbonate hydroxyapatite which from eggshell is even more deficient. Carbonate hydroxyapatite (CHAP) synthesized from eggshell waste was used for removing fluoride ion from aqueous solutions. The project intends to prepare a new fluoride removal materials using eggshell, which is modified by LMWOAs, in order to improve the fluoride removal capacity. The main research contents include: (1)Adsorption behavior and mechanism of LMWOAs by CHAP, as well as the effects of LMWOAs on the release of phosphorus from CHAP; (2) A simplified system of high fluoride water was simulated to evaluate the defluoridation capacity of eggshells promoted by LMWOAs; (3) In the presence of three kinds LMWOAs, the difference in mechanism of defluoridation by CHAP; (4) Summerize the benefis of eggshell-CHAP, by comparing CHAP with other adsorbents, which is both hithly effective and environmentally friendly material for the removal of fluoride from wastewater.This work has important signification in the protection of human health from drinking water and reuse of waste resources.

依照我国饮用水中氟的含量标准（＜1.0 mg/L），国内受氟威胁的人群高达 2.6 亿，所以控制和减少饮用水中的氟含量是十分必要的。蛋壳作为一种含钙多孔固体废物，具有较大的比表面积和良好的吸附性能而表现出巨大的去氟潜力。考虑到蛋壳直接利用时的局限，本项目拟用蛋壳制备碳羟基磷灰石（CHAP），从外源添加低分子量有机酸（LMWOAs）的角度探索羟基基团对"蛋壳源碳羟基磷灰石"去氟性能的影响。阐明表面羟基化的CHAP的去氟机理。具体包括：（1）CHAP与LMWOAs相互作用机理研究；2） LMWOAs羧基上的羟基基团如何影响CHAP的去氟性能；（3）不同LMWOAs对CHAP去氟机理的影响；（4）总结研究成果，并与其它去氟材料详细比较，为蛋壳的环境应用提供依据。本项目对于解决高氟地区饮水问题和开发废弃物资源化具有重要的理论与实践意义。

依照我国饮用水中氟的含量标准（＜1.0 mg/L），我国因饮用水中氟浓度过高而受氟威胁的人群高达2.6亿，因此控制和减少饮用水中的含氟量是十分必要的。本项目以固体废弃物—蛋壳为钙源，制备出碳羟基磷灰石（CHAP），研究“蛋壳源羟基磷灰石”与低分子量有机酸的相互作用及表面羟基化的碳羟基磷灰石的去氟性能。项目按预期计划进行，完成了预定的试验研究并进行了相关理论分析。.本项目通过条件优化有针对性的合成了不同类型的纯度高和比表面积大的纳米碳羟基磷灰石，并对合成的样品的形态、结晶度、粒度、孔隙度和溶解度等进行了系统表征和测定，并将制得的“蛋壳源碳羟基磷灰石”应用于处理水体中的氟物质等；探索了碳羟基磷灰石与低分子量有机酸相互作用机理；研究了低分子量有机酸羧基上的羟基基团如何影响碳羟基磷灰石的去氟性能以及不同低分子量有机酸对碳羟基磷灰石去氟机理的影响。本项目对于解决高氟地区饮水问题和开发废弃物资源化具有重要的理论与实践意义。.项目研究既涉及学科前沿，也结合水环境安全战略需求。在完成预定的研究任务的同时，研究内容还有所扩充和延展。在项目资助下，已在学术期刊上发表了标注有国家自然科学基金本项目编号的研究论文8篇（其中：国外英文SCI 7 篇，国内期刊1篇），另有一些论文正在撰写或审稿中。项目研究期间资助或部分资助了7位本科生完成学位论文。