表面脲、西弗碱官能化凹凸棒土对氟离子的检测、吸附及其机理研究

It is very important to develop materials which can treat fluoride contained drinking water in a low cost, simple operation and environmental -friendly way because the high concentration (more than 1.0mg/L)of fluoride in water is a serious threat to human health. According to the characteristics of natural attapulgite (ATP)clay itself from Linze (a county of Zhangye in China central hexi corridor of Gansu province)and targeting at detecting ,adsorbing and seperating F- . this research project will firstly study the preparation of two series of new surfactant functionalized attapulgite (SFA) organic-inorganic composite material SFA-1 and SFA-2, which sepetately contain urea(thiourea) and schiff base(hydrazone) organic structural units prepared after being modified with silane coupling agent, and characterized through IR, XRD, TG/TGA, XPS, SEM so as to confirm the structure of the SFA materials. Then, The influencing factors such as temperatures, mass ratios of attapulgite, time and pH will be investigated to receive the optimum adsorption conditions of fluoride adsorption onto each SFA materials, in which the detection, adsorption and separation of fluoride onto SFAs in water and its mechanism will be studied. At last, 3-5 kinds of SFAs which have good adsorption capability to fluoride ion will be choosen to treat fluoridated water samples, the practical application of the SFA materials will be systematically investigated to filter out 1-2 kinds of materials with practical value for fluorine-containing drinking water purification. By doing this, it is expected to offer a possible solution and reference for the treatment of fluorinated water.

高氟水危害众多，开发花费少、效果好、环境友好的饮用水除氟材料具有重要的科学研究意义和社会效益。本课题基于地域(甘肃省张掖市临泽县，河西走廊中段)优势资源凹凸棒土本身结构特征，以含氟水体系中氟离子检测、吸附及分离为目标，在甘肃临泽凹凸棒石酸处理及热活化的基础上通过硅烷偶联剂首先合成两个系列的分别含（硫）脲及西弗碱（腙）结构单元的有机改性凹凸棒土新材料SFA-1和SFA-2，通过常规表征确证其结构特征；在此基础上研究这两个系列的有机改性凹凸棒土材料对氟离子的选择性检测及吸附能力，筛选出3-5种合格的改性材料，并对其检测和吸附分离机理进行探讨；最后采取实际生活中的含氟水样，对改性材料的实际应用性进行系统考察，筛选出1-2种具有实际应用价值的含氟饮用水净化处理材料，为含氟水处理提供可能的方案及参考。

高氟水危害众多，开发低价、高效、环境友好的除氟材料具有重要的科学研究意义和社会效益。本项目基于地域(甘肃省张掖市临泽县，河西走廊中段)优势资源凹凸棒石本身结构特征，以含氟水体系中氟离子检测、吸附及分离为目标。对临泽县3个矿点样品进行了取样表征，普遍棒晶粗短，颜色较深，含铁量2-5%左右，伴生二维层状黏土，有利于吸附功能发挥，高值化利用须关注低成本转白及混维特性两个方面。在凹凸棒石常规活化处理基础上制备了系列Zr/Al基M-ATP及MOFs@ATP功能材料并确证了吸附前后结构变化，通过氟离子选择电极法（GB/T5750-2006）系统研究了其F-吸附去除性能，其中Zr-ATP和Al-ATP吸附容量可达45mg/g以上，低浓度下(10mg/g)可达到国标饮用水标准（1.0mg/g），吸附过程通过表面-OH置换与氢键协同实现，吸附过程对pH敏感，可在碱体系脱附再生，5次后仍保持较高吸附性能，表明Zr/Al负载凹凸棒石策略可有效用于水体氟离子吸附去除。进一步设计合成了系列高吸附容量的Zr/Al基MOFs@ATP功能材料，UiO-66-NH2@ATP吸附容量86mg/g，以凹凸棒石酸溶出液构筑的Mg-Al-Zr三组分LDHs体系吸附容量可达247mg/g, UiO-66(Zr)@ LDHs吸附容量可达372mg/g，有效实现了高浓度氟离子的去除。F-检测方面，设计并制备了2个系列含脲/西弗碱结构氟离子检测主体，通过UV-Vis或荧光光谱系统研究了其阴离子检测性能，测定了各主体与阴离子的结合能力，检出限及线性范围等，结合理论计算和核磁滴定探讨了检测机理，结果表明该类主体通过-OH/NH氢键及高浓度脱质子过程实现F-的结合，芳环上的官能团调控可有效调控其选择性检测能力，普遍具有抗干扰能力强，检出限低等优点，可实现对特定阴离子的裸眼检测和光谱响应，有望作为F-检测试剂。同时还研究了相关材料对刚果红，Cr(Ⅵ)，CN-等污染物的吸附及检测性能，拓展了其应用范围。. 总的来说，金属负载及MOFs负载凹凸棒石功能材料可有效用于水体氟离子的清除，脲/西弗碱官能化主体化合物可用于高效氟离子检测，项目实施为氟离子检测与去除提供了科学依据和实践案例。