功能性有机粘土强化去除水体中有毒有害污染物的研究

The adsorption research onto organoclay is a challengeable subject in sewage treatment. It has been an urgent task to find out how to effectively design of modifier and conduct the adsorption of novel organoclay. This work is aimed to reveal the important chemical problems and the scientific essence of contaminant adsorption onto novel organoclays. A series of novel bisquaternary ammonium salts and bipyridinium salts will be designed, synthsized and charaterized. They are used to modify several minerals with different layer charge for preparing functional organoclays. The microstructure and wettability of the organoclays before and after adsorption are characterzied by FT-IR, XRD, and Contact Angle Measuring Device, and so on. The influences that the structure of modifer and the properties of clay have on the structures and sorption characteristics of organoclays will be investigated. A deep understanding about the structure-adsorptive capacity relationship of the pollutants adsorption by organoclays is studied systematically. Additionally, the kinetic model, adsorption isotherms and adsorption mechanism of one-component or multicomponent contanmiants are conducted on the novel organoclays. A batch of experiments will be carried out to optimize the adsorption conditions and obtain organoclays adsorbents that match the contaminants. The approach of molecular design is first proposed by establishing the correlation among layer charge, organic modifier and contaminant. The problems on regeneration of organoclays and recyle of available resources in the waste water are also addressed. This work will provide scientific basis and theoretical guidance for further design of highly efficient modifiers and high-performance organoclay adsorbents.

有机粘土矿物的吸附研究是目前污水处理领域中极富挑战性的课题之一，有效地开展新型改性剂分子设计和有机粘土的吸附性能研究已成为一项迫在眉睫的工作。本课题旨在揭示新型有机粘土吸附各种污染物中的重要基础化学问题和科学本质。拟设计和合成新型系列双季铵盐和双吡啶盐改性剂，以不同层电荷的几种粘土矿物为原料，制备功能性有机粘土。通过FT-IR、XRD和接触角测量仪等方法表征有机粘土吸附污染物前后的微观结构和润湿性变化，系统研究改性剂结构及矿物性质对有机粘土结构与性能的影响，揭示有机粘土对污染物吸附的构-效关系。阐明单一或多组分污染物在有机粘土上的吸附热力学、动力学及吸附机理，优化吸附条件，得出与污染物相匹配的有机粘土吸附剂，建立不同层电荷粘土-有机改性剂-污染物三者之间相互关联的分子设计方法，并着眼于有机粘土再生及可利用资源的回收，为进一步设计高效有机改性剂和高性能有机粘土吸附剂提供科学依据和理论指导。

有机粘土矿物的吸附研究是目前污水处理领域中极富挑战性的课题之一，有效地开展新型改性剂分子设计和有机粘土的吸附性能研究已成为一项迫在眉睫的工作。本课题设计和合成了新型系列具有特殊结构（如不同链长、间隔基、官能团和头部基团等）的对称/不对称双季铵盐、双吡啶盐和双咪唑季铵盐，以不同层电荷的几种粘土矿物（如蛭石、纳米二氧化硅及蒙脱土）为前驱体，制备了多种功能性有机粘土吸附剂。通过N2吸附-脱附、FT-IR、元素分析、X-射线衍射（XRD）、扫描电镜（SEM）、透射电镜（TEM）、热重分析（TG-DTG）、晶畴计算（谢乐方程）和接触角测量仪等方法表征了有机粘土吸附单一/多元污染物前后的微观结构、形貌特征和润湿性变化规律，研究了反应温度、反应时间、溶液pH、吸附剂用量、污染物初始浓度等因素对有机粘土吸附性能的影响，从而优化了吸附条件。考察了新型系列有机粘土吸附剂与污染物之间的相互作用（如氢键作用、XH-π、π-π效应）以及官能团之间特殊相互作用（cation-π，n-π相互作用）对有机粘土微观吸附性能的影响。系统研究了改性剂结构及矿物性质对有机粘土结构与性能的影响，揭示了有机粘土对污染物吸附的构-效关系，阐明了单一或多组分污染物在有机粘土上的吸附热力学、等温线、动力学及其吸附机理。此外，通过统计物理模型的拟合，理论计算，吸附后吸附剂的表征，正辛醇-水分配系数（Kow）和有机物校正吸附系数（Kom）的对比，深入探明了有机粘土的吸附构-效关系及其吸附机理。最后，得到了与特点污染物相匹配的多种高效有机粘土吸附剂，建立了不同层电荷粘土-有机改性剂-污染物三者之间相互关联的分子设计方法，确立了适合已用有机粘土的简便的溶剂（如水、盐酸稀溶液或乙醇溶液）淋洗再生方法及其循环利用，为进一步研制高性能吸附剂提供了科学依据和理论指导，这对促进廉价粘土矿物资源的高效利用具有重大实际意义。项目执行期间，在Chem. Eng. J., Adv. Colloid Interfac., J. Hazard. Mater. 等期刊上发表论文22篇；申请中国发明专利4项；项目组成员参加国内外学术会议7人次。