蒙脱石有机改性对邻苯二甲酸二丁酯吸附的影响

以钠蒙脱石和十六烷基三甲基溴化铵(CTAB)有机改性蒙脱石为吸附剂对水溶液中的邻苯二甲酸二丁酯(DBP)进行了静态吸附对比。考察吸附时间、溶液初始p H等因素对吸附效果的影响,研究了DBP在蒙脱石有机改性前后的两种吸附剂上的吸附机制。结果表明,有机改性后的蒙脱石吸附效果更好,吸附的主要机制是表面吸附,有机改性蒙脱石还存在分配吸附作用。     

不同粘土矿物与聚羧酸减水剂相互作用机理研究

通过X射线衍射(XRD)、红外光谱(IR)、有机碳吸附(TOC)、饱和吸水率以及净浆流动性等试验方法,研究了不同粘土矿物与聚羧酸减水剂的相互作用机理.结果表明:聚羧酸减水剂的侧链可进入粘土矿物蒙脱石的层间,发生插层反应,即层间吸附,而其侧链结构不进入伊利石、高岭土、海泡石等粘土矿物的层间,仅发生表面吸附,且吸附量大小为蒙脱石>高岭土>海泡石>伊利石;饱和吸水率试验显示,粘土矿物的饱和吸水率大小为蒙脱石>高岭土>海泡石>伊利石;流动度试验表明,粘土矿物对水泥-减水剂体系净浆流动度均有不同程度的影响,且蒙脱石影响程度最大.由此可知,粘土矿物对自由水和聚羧酸减水剂的吸附是造成流动度损失的主要原因.     

改性蒙脱石在污水处理中的应用现状及进展

综述了近年来各种改性蒙脱石对于污染物(包括重金属离子、阳离子染料、阴离子染料、疏水性有机物等)在污水处理中的应用以及研究进展。从酸改性、热改性、有机改性、无机改性和有机-无机改性几个改性方法出发,介绍了各种吸附材料的开发以及研究,并系统地分析了其吸附机理和吸附特性,最后对基于蒙脱石改性材料的进展提出展望,简要讨论了其开发前景和研究方向,以期为后续的新型蒙脱石吸附材料的开发提供参考。     

改性膨润土在废水处理中的应用

膨润土是一种由蒙脱石构成的粘土矿物，广泛地应用于工业、农业和其他领域。目前膨润土已开始应用于废水处理中，但是未经改性的膨润土对去除废水中有机物和脱色效果较差，故一般用于废水处理的膨润土都要经过改性，增大其比表面积，提高吸附能力。对国内外膨润土在废水处理领域的应用及研究现状、改性方法、活化方法等做了概述，并展望了其应用前景。     

粘土矿物成分对聚羧酸减水剂吸附性能的研究

劣质砂石料中的含泥对聚羧酸减水剂的性能具有强烈的抑制作用,表现为混凝土坍落度损失快,工作性能变差等.通过对粘土中蒙脱石、伊利石、高岭石等粘土矿物成分的砂浆流动度和吸附量随时间变化规律的研究,表明蒙脱石对聚羧酸减水剂的吸附能力最强.从分析矿物的晶体结构上探讨了粘土矿物成分对聚羧酸减水剂吸附的作用机理.     

钠基蒙脱石和叶蜡石吸附水溶液中的铜离子研究

选用钠基蒙脱石和叶蜡石两种粘土矿物吸附水中的铜离子,研究了pH值、铜离子初始浓度和时间对吸附效果的影响。所得的热力学数据与等温线方程模拟,发现这两种矿物吸附铜离子的模型均较符合朗缪尔模型,说明在粘土矿物的表面吸附位点基本上是相同的。将动力学数据与几种动力学方程进行模拟,发现粘土矿物吸附铜离子的动力学更好的符合二级动力学模型,说明吸附速率不仅跟吸附质的浓度有关,也跟吸附剂的浓度有关。     

蒙脱石及其衍生物吸附水体中二价镉的研究进展

含Cd2+废水危害人类健康,通过蒙脱石类吸附剂处理Cd2+的研究受到广泛关注.文中对相关报告进行归纳总结,从蒙脱石的理化特性、无机改性、有机改性、复合改性、吸附性能和竞争吸附等方面的阐述表明了蒙脱石及其衍生物去除水体中Cd2+具备的良好可行性.然而,对于吸附的微观机理、多组分重金属废水的吸附和有关蒙脱石改性、再生成本等经济可行性方面还需要进一步深入研究.     

羧甲基田菁胶对高岭石,蒙脱石吸附机理的研究

运用红外光谱、差热分析、Ｘ射线衍射分析及化学分析方法，比较详细地研究了一种典型的有机大分子－羧甲基田菁胶对高岭石、蒙脱石这两种粘土矿物的吸附机理，确定了吸附性质、吸附方式及试样的相对吸附量。结果表明：羧甲基田菁胶与高岭石蒙脱石的吸附主要呈化学键，但对这两种矿物的化学结合方式是不同的。     

改性粘土矿物吸附处理硝酸盐的研究进展

综述了现有的粘土矿物材料吸附处理水中硝酸盐的相关研究,并按照热改性、酸活化、表面活性剂改性、其他有机基团接枝改性这4类改性方法进行了分类与总结。对4类改性方法存在的问题进行了初步分析,并据此提出了未来应用改性粘土矿物吸附硝酸盐面临的挑战和研究方向。     

复合改性蒙脱石的制备及对甲基橙吸附性能的研究

本实验分别用CTAB(十六烷基三甲基溴化铵)和三氯化铁对蒙脱石进行有机改性和无机改性,并探究了其对甲基橙吸附能力的研究。通过实验得出复合改性后的蒙脱石对甲基橙的最佳吸附条件为:吸附时间为75 min,甲基橙的浓度为32 mg/L,复合改性蒙脱石与32 mg/L的甲基橙溶液的最佳固液比为6. 4∶1,在最佳吸附条件下有机-无机复合改性后的蒙脱石对甲基橙的吸附率可达到97. 96%,未改性的蒙脱石吸附率只有57. 41%,复合改性后的蒙脱石对甲基橙的吸附率有显著的提高。     

改性蒙脱土去除水中重金属离子研究新进展

重金属离子污染具有非降解性、持续存在和累积的性质,影响着人类的生命安全。如何从水中去除重金属离子已经成为治理水污染的核心问题之一,其方法之一就是采用改性蒙脱土进行吸附处理。本文介绍了近年来重金属离子吸附用改性蒙脱土的研究新进展,重点回顾了无机改性蒙脱土、有机改性蒙脱土和无机有机复合改性蒙脱土的改性方法及其对重金属离子的去除能力及机理。提出今后改性蒙脱土研究的主要方向是合成多功能高吸附性的蒙脱土高分子复合微球、蒙脱土高分子凝胶和滤膜材料等,为今后改性蒙脱土作为重金属离子优良吸附剂的研究有一定的指导意义。     

Preparation and characterization of novel organo-clay minerals for Hg(II) ions adsorption from aqueous solution

Novel organo-clay minerals for adsorption of Hg(II) ions were prepared. The clay minerals were grafted with 2-(3-(2-aminoethylthio)propylthio)ethanamine (AEPE). AEPE-montmorillonite and AEPE-hectorite were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA), CHN element analysis (EA) and surface area analysis. The XRD patterns indicated that the chelating agents (AEPE) were mainly grafted on the external surface of montmorillonite while AEPE was grafted on both the external and interlayer surfaces of hectorite. The results from IR, TGA and EA showed a difference in chemical composition of the unmodified and modified clay minerals. The results confirmed that montmorillonite and hectorite were modified with the desired organic groups. The extent of ligand loading depended on the nature of the clay mineral. The AEPE-modified clay minerals were good chelating materials for Hg(II) ions, compared to the unmodified clay minerals. The adsorption capacity for Hg(II) of AEPE-montmorillonite and AEPE-hectorite was 46.1 and 54.7 mg g^− 1, respectively, for solution containing 140 mg L^− 1 Hg(II) ions (pH 4).     

膨润土改性及其在钻井液方面的应用

膨润土(Bentonite),主要成分粘土矿物-蒙脱石,以两层Si-O四面体中夹一层Al-(O,OH)八面体作为构造单元构成的层状硅酸盐矿物。膨润土是调整钻井液流变性和滤失性的重要天然矿物材料。通过改善天然膨润土水化性和吸附性,使得膨润土滤失效果增强,与其他处理剂的协同能力得到提高,从而显著改善钻井液性能。主要介绍了膨润土的有机改性工艺在钻井液方面的应用,并探究了改性后的膨润土在超深井的高温高压条件下的作用效果,以期为相关研究提供参考。     

以天然硅铝质黏土矿物为原料制备沸石分子筛及其应用

沸石分子筛是一种具有规则孔道结构的硅铝酸盐晶体,在气体吸附分离、工业催化、重金属离子污染治理等领域被广泛应用.传统沸石分子筛的水热合成常以含硅、铝的化工产品以及有机模板剂为原料,不仅价格昂贵,且污染环境.因此,开展以天然黏土为原料绿色合成沸石分子筛的相关研究,将廉价的天然黏土资源转化成高附加值的化工产品,具有重要的研究...     

蛭石在重金属离子废水处理中的应用

蛭石是黏土矿物的一种,具有较大的比表面积和较强的阳离子交换容量,能有效去除废水中的重金属。文章总结了近年来蛭石吸附Cu2+、Cd2+、Ni2+、Pb2+等重金属离子的研究状况,发现其去除重金属离子的机理主要是离子交换和表面络合作用。分析了溶液pH值、吸附时间、蛭石粒径、蛭石投加量、溶液浓度对吸附效果的影响。指出应进一步加深对蛭石吸附机理和吸附后处置技术的研究,以及蛭石在实际工程上的应用推广。     

Interaction of metal ions with montmorillonite and vermiculite

The behaviour of montmorillonite and vermiculite toward adsorption of Cd²⁺, Pb²⁺, Zn²⁺, Mn²⁺, Cu²⁺ and Zn²⁺ was compared. In general, the uptake of metal ions on both clay minerals decreased with decreasing of pH and in the presence of ligands forming stable complexes. Metal ion retention on montmorillonite was less affected by the competition of sodium ions at high ionic strengths with respect to vermiculite. On the other hand, the total capacity of vermiculite with respect to the investigated metal ions was found to be much higher than that of montmorillonite, whereas the order of affinity of the metal ions for the two clay minerals was similar, i.e.: Pb²⁺ = Cd²⁺ < Cu²⁺ < Zn²⁺ < Mn²⁺ < Ni²⁺ for montmorillonite and Pb²⁺ < Cu²⁺ < Cd²⁺ < Zn²⁺ < Ni²⁺ < Mn²⁺ for vermiculite.The similarities and differences between the two clay minerals were also investigated by principal component analysis and hierarchical cluster analysis.The results of this study may be used to predict the uptake efficiency of these adsorbents in view of their application for the removal of metal ions from contaminated effluents. The choice of vermiculite or montmorillonite for the uptake of metal ions or other elements will depend on the composition of the effluent to be treated.     

Efficiency of different clay minerals modified with a cationic surfactant in the adsorption of pesticides: Influence of clay type and pesticide hydrophobicity

In the present work we studied the efficiency of a series of clay minerals (montmorillonite, illite, muscovite, sepiolite and palygorskite) modified with the cationic surfactant octadecyltrimetylammonium bromide (ODTMA) in the adsorption of the pesticides penconazole, linuron, alachlor, atrazine and metalaxyl. A study was also carried out on the effect of the structure (expansible and non-expansible layered, and non-layered), the surface area and charge density of the clay minerals, and the hydrophobicity of the pesticides (K_ow) on the adsorption process. Adsorption–desorption isotherms of the pesticides by clay minerals were obtained and the constants of the Freundlich model (K_f and K_fd) (natural clays) and of the linear model (K and K_des) (ODTMA-clays) were determined. Correlation coefficient values (r²) found between K and K_des, and organic matter (OM) content of ODTMA-clays indicate a more effective partitioning of the pesticides in the organic phase of ODTMA after desorption. Furthermore the positive significant correlation found between the K_desom values and the charge density of different ODTMA-clays indicates that a higher density of ODTMA in the clay gives rise to the formation of an organic phase more effective for the partition of the pesticides. This correlation explained that the highest K_desom value obtained was for kaolinite and the lowest K_desom value was for montmorillonite in the adsorption of all pesticides by the different organo clays. Simple correlations between adsorption constants and K_ow values, and multiple correlations between these constants and clay OM contents and K_ow values were also calculated. The results obtained indicate the interest of ODTMA-clays in the adsorption of hydrophobic pesticides. Non-expandible layered and fibrous clay minerals may also be of interest as adsorbents derived from their density charge, and these minerals, when modified with ODTMA, and used in appropriate amounts, higher than that of montmorillonite, or when present in soils with high clay contents, even in the absence of montmorillonite, may be good adsorbents for hydrophobic pesticides. According to the results of the study, ODTMA-clays and ODTMA-soils could be used as barriers to prevent the mobility of certain hydrophobic pesticides from a point source of pollution.     

页岩中黏土矿物吸附特性分子模拟

页岩的吸附解吸特性对页岩气资源开发具有重要意义。为深入了解页岩中黏土矿物微观吸附机理, 利用Material Studio 分子模拟软件构建了伊利石、蒙脱石和高岭石3种黏土矿物分子模型, 采用巨正则Monte Carlo(GCMC)方法对3种模型的等温吸附量和吸附热进行了模拟计算。研究表明, 在相同温度和压力条件下3种黏土矿物对CH₄分子的吸附量大小顺序是伊利石>蒙脱石>高岭石;随压力增大3种黏土矿物对CH₄分子的吸附量均有所增加, 而且伊利石和蒙脱石对CH₄分子的吸附量对压力变化更为敏感;3种黏土矿物的等量吸附热均小于42 kJ·mol^-1, 对CH₄的吸附为物理吸附;随着温度的升高, CH₄分子的吸附热和吸附量均减小。     

凹凸棒石粘土的分离性能及其在离子色谱固定相研究中的应用前景

凹凸棒石粘土具有独特的空间结构和较大的比表面积,具有较强的离子交换性质和吸附性质,应用广泛。其对金属离子和有机污染物的吸附研究报道较多。利用其对不同组分的吸附作用的差异和选择合适的流动相,凹凸棒石粘土可用作离子色谱固定相。本文总结了凹凸棒石粘土对金属离子和有机污染物的吸附作用研究,分析了其作为离子色谱固定相的巨大潜力。