硝酸改性凹凸棒石粘土及吸附Cu2+的工艺研究

将凹凸棒石粘土用硝酸进行改性处理,然后用于对含铜废水中铜离子的吸附,研究了硝酸浓度、改性凹凸棒石粘土用量、吸附时间、pH值等因素对吸附性能的影响。结果表明:经4mol/LHNO3改性处理后的凹凸棒石粘土吸附能力最好,凹凸棒石粘土加入量为30g/L,水样pH值为4,超声搅拌20min,废水中Cu2+的吸附率接近99%,同时吸附剂的再生实验表明,复用时吸附量下降平缓,可以重复使用。     

不同矿石类型凹凸棒石黏土热处理后对磷的吸附性能

从明光官山采集灰白色、粉红色凹凸棒石、蒙脱凹凸石棒石、蛋白石凹凸棒石和白云凹凸石凹凸棒石黏土样品,在400~800℃对各种类型矿石样品进行热处理改性,通过X射线衍射分析表征热处理前后样品的物相组成和结构,通过静态吸附实验考察了各种类型矿石样品煅烧前后对低浓度磷的吸附效果。结果表明:白云石凹凸棒石矿石煅烧后具有较好的吸附除磷效果,吸附除磷最佳热处理温度为600~700℃,这是由于白云石凹凸棒石中的纳米凹凸棒石和亚微米多孔状的白云石在600~700℃热处理过程当中发生了热分解和化合反应,新形成的物相方镁石、石灰、斜硅钙石和灰硅钙石对磷的沉淀和吸附起到重要作用。     

用稀土改性凹凸棒石粘土净化柴油机尾气

在喷射鼓泡反应器中用凹凸棒石粘土溶液吸收脱除柴油机尾气中的碳烟颗粒物、NOx及其它污染物质而使之净化。凹凸棒石粘土吸收液具有胶体特性,可改善碳烟颗粒的润湿性能,并对NO,SO2的氧化具有催化作用,因而对尾气中的碳烟颗粒物、NOx和SO2等污染物具有良好的脱除效果。粘土经稀土改性,可提高NOx的脱除率。在实验条件下,尾气中的碳烟脱除率达71．3％,NOx的脱除率为90．6％,HC和SO2等有害气体的脱除率均高于90％。对改性凹凸棒石粘土的净化机理进行了探讨。     

凹凸棒石粘土及在水处理中的应用

凹凸棒石粘土是一种以凹凸棒石为主要成分的天然非金属粘土矿物，它是一种具有独特层链状结构的晶质水合镁铝硅酸盐矿物，具有比表面积大、化学稳定性好、吸附能力强等特征。作者对国内外有关凹凸棒石粘土的文章进行了综述，详细叙述了凹凸棒石粘土的组成和结构以及相应的改性方法，分类讨论了凹凸棒石粘土在水处理中的应用，分析了我国在研究开发过程中存在的问题，并提出了相应的意见和建议。     

壳聚糖碳化改性凹凸棒石对Cr(Ⅵ)的吸附性能

以壳聚糖为生物质碳源,通过一步水热碳化法对凹凸棒石进行亲有机改性,对改性凹凸棒石进行表征,研究了其对Cr(Ⅵ)的静态和动态吸附性能,对其除Cr(Ⅵ)机制进行了初步探讨.结果表明,改性凹凸棒石表面有丰富的羟基、氨基和羧基等有机官能团,壳聚糖碳化产物成功负载于凹凸棒石表面.在实验的pH值范围内,总铬去除率随pH值增加先增大后减小,pH为1和2时总铬去除率分别为11.7%和80.8%,pH为3时总铬去除率降至10.2%.总铬吸附量随Na~+浓度增加而降低.对总铬的吸附等温线符合Langmuir模型,最大吸附量高达204.1 mg/g.改性凹凸棒石对总铬的动态吸附主要受颗粒内扩散控制,在强酸性条件下(pH=2),去除Cr(Ⅵ)是吸附-还原-再吸附的耦合过程.     

漆酚改性凹凸棒石载铜抗菌剂制备及在TPU中应用

以酸活化凹凸棒石为载体,漆酚为表面修饰剂,CuCl₂为铜离子源,制备了凹凸棒石载铜抗菌剂,并通过熔融共混挤出制备了抗菌热塑性弹性体(TPU)材料。着重研究了漆酚改性对凹凸棒石Cu²⁺载量的提升作用,以及漆酚改性前后凹凸棒石负载Cu²⁺抗菌剂对TPU物理性能和抗菌性能的影响。结果表明,漆酚的配位作用有效提升了凹凸棒石载铜能力,漆酚改性后凹凸棒石载铜负载量从13.7 mg/g提升至45.6 mg/g。漆酚与TPU基体有良好的相容性,漆酚改性的凹凸棒石载铜抗菌剂在TPU基体中呈良好分散性,在赋予TPU优异抗菌性能的同时可以有效提升材料的拉伸强度。添加1%漆酚改性凹凸棒石载铜抗菌剂时,对大肠杆菌和金黄色葡萄球菌的抑菌率均为100%,材料的拉伸强度从34.14 MPa提升至43.27 MPa。     

改性凹凸棒石粘土吸附工艺的研究

凹凸棒石粘土（凹土）是一种具有独特纤维状或棒状晶体形态的含水富镁铝硅酸盐矿物，由于其特殊的晶体结构，使其具有优异的吸附性能，在含重金属离子的废水处理中已有广泛应用。本文利用硝酸改性后的凹土作为吸附剂，用于废水中Cu^2＋的吸附处理研究，从理论上对其吸附性能的改变进行了探讨，为其工业化提供了工艺参数和理论依据。采用不同浓度硝酸活化改性凹凸棒石粘土吸附剂处理含铜废水，     

凹凸棒石改性方法及研究进展

凹凸棒石具有广泛的工业应用价值,但是天然凹凸棒石含有大量杂质,吸附能力不高、吸附选择性差,因此需要进行改性以提高凹凸棒石的性能。本文简述了凹凸棒石的表面改性技术。总结了现阶段对改性凹凸棒石的相关研究进展。     

凹凸棒石粘土对阳离子染料吸附性能的研究

1 前言 凹凸棒石是一种含水富镁硅酸盐矿物,其理想的化学分子式为Mg_5Si_8O_2。(OH)_2(OH_2)_4·4H_2O。凹凸棒石具有层链状的结构特性,带有与沸石类似的孔道。由于其独特的晶体结构,因而具有很好的吸附脱色性能。本文采用我省皖东地区凹凸棒石粘上,经过高温焙烧活化处理,制成凹凸棒石粘土吸附剂,用于阳离子染料溶液的吸附脱色试验。试验考察了吸附剂的静态吸附容量、阳离子染料溶液的初始浓度、吸附剂颗粒的粒径、吸附剂加入量和吸附温度等因素对吸附过程的影响。     

天然青海湖水浸泡凹凸棒石对胶体性能的影响

利用天然青海湖水浸泡凹凸棒石黏土,考察了浸泡时间对其胶体性能的影响.红外光谱(FTIR)、X-射线衍射(XRD)、扫描电镜(SEM)和Zeta电位分析以及胶体性能测试结果表明,湖水浸泡未改变凹凸棒石的晶体结构和棒晶形态,湖水中的金属离子与凹凸棒石棒晶表面的离子发生了交换反应.浸泡90 d后凹凸棒石的表面电荷增加,浸泡180 d后样品旋转黏度从1188 mPa·s提高到2376 mPa·s,胶体稳定性也最好.     

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。     

Synthesis of magnetically modified palygorskite composite for immobilization of Candida sp. 99–125 lipase via adsorption

Magnetically modified palygorskite composites were synthesized withγ-Fe2O3 dispersing on the external surface of clay mineral. The magnetic clay was characterized with Fourier transform infrared, X-ray diffrac-tion, transmission electron microscopy, and vibrating sample magnetometer. Candida sp. 99–125 lipase was immobilized on magnetic palygorskite composites by physical adsorption with enzyme loading of 41.5 mg·g-1 support and enzyme activity of 2631.6 U·(g support)-1. The immobilized lipase exhibit better thermal and broader pH stability and excellent reusability compared with free lipase.     

PAM和粘土矿物的相互作用试验研究

选用不同电性、电量及分子量的PAM、两种典型的纯净粘土矿物样本,就PAM对分散的粘土颗粒的絮凝能力和机制、粘土矿物对PAM的吸附及解吸附进行了研究。结果表明,在没有阳离子桥的情况下,3种PAM对粘土矿物的絮凝能力依次为：阳离子PAM〉非离子PAM〉阴离子PAM,阳离子PAM为有效的絮凝剂,而阴离子PAM则为分散剂;粘土矿物对PAM的吸附量除与PAM的电性关系非常密切外,也受到粘土矿物本身特性的影响,尤其是所带电荷的性质与数量及比表面积的大小;PAM一旦被粘土颗粒所吸附,解吸附几乎是不可能的。PAM与粘土间复杂错综的了互作用姜系拘威了PAM在￡壤政虞、混水净化中应用的理论基础。     

Acid treatment of south Tunisian palygorskite: Removal of Cd(II) from aqueous and phosphoric acid solutions

The object of this work is to study the modifications of Tunisian palygorskite upon HCl treatment and to investigate the ability of natural and acid treated palygorskite to adsorb heavy metal ions. Chemical analysis, X ray diffraction, infrared spectra, MAS-NMR methods, BET surface and surface charge of HCl treated palygorskite have been reported. It was established that acid leaching at reflux temperature resulted in an increase in the amount of Mg, Fe and Al extracted and in surface area from 59.7 to 437 m² g^− 1 for 2 M HCl samples and from 59.7 to 360 m² g^− 1 for 4 M HCl samples, due to a dissolution of the octahedral sheet and the creation of mesoporosity. ²⁹Si-MAS-NMR studies yield information on changes occurring in the structure of the mineral. During acid treatment the clay structure is progressively transformed into amorphous silica (essentially for samples treated by HCl 4 M for 10 h and HCl 2 M for 35 h).Natural palygorskite and the activated samples were applied as adsorbents for the removal of Cd(II) from aqueous solutions. The effects of various experimental parameters were investigated. The adsorption isotherms of activated palygorskites for Cd(II) could be described by the Freundlich model. The acid activated sample showed a higher adsorption capacity for Cd(II) than the natural palygorskite. The retention of Cd(II) ions by palygorskite occurs dominantly by specific adsorption. A different behaviour was observed in the phosphoric acid medium. Despite increases in the surface areas upon acid activation, improvements in the adsorption were not observed, as a result of the decreasing number of negative surface sites, as main centers for specific adsorption.     

Vapor Adsorption of Volatile Organic Compounds Using Organically Modified Clay

Abstract

Organically modified clay was used to adsorb volatile organic compounds from a gaseous phase. The organoclay was prepared by adsorbing hexadecyltrimethylammonium (HDTMA) on the surface of montmorillonite particles. Two volatile organic compounds (VOCs), chlorobenzene and trichloroethylene, were adsorbed to the organoclay using a fixed adsorption bed. The adsorption was carried out at various inlet concentrations of gaseous VOCs in a carrier gas (nitrogen). The adsorption behavior of VOCs was investigated using natural clay and two types of organoclays, which had different HDTMA loadings. Adsorption breakthrough curves were obtained, and the adsorption data were modeled with two adsorption isotherms. Desorption of VOCs was also conducted using pure nitrogen, and the desorption profiles were fitted with two different theoretical models. It was found that the organoclay possesses significant adsorption capacity towards VOCs and the uptake depends on the degree of HDTMA loading on clay surface.     

阴-阳离子有机坡缕石对对苯二酚的吸附行为

采用微波辅助法制备了一系列阴-阳离子表面活性剂改性坡缕石,研究了改性坡缕石对水中对苯二酚的吸附.结果表明,经阴-阳离子表面活性剂改性后的坡缕石对对苯二酚的吸附能力远大于坡缕石原土及阳离子表面活性剂改性的坡缕石.改性坡缕石对对苯二酚的最大吸附量为137.5 mg/g.等温吸附过程可以用Langmuir方程进行较好拟合,热力学函数计算表明,吸附剂对对苯二酚的吸附是自发的放热过程,吸附热和熵变分别为-93.582 kJ/mol和-299.32 J/mol·K,吸附自由能随温度的升高而增加.     

坡缕石吸附材料的研究进展

简述了近几年来国内外对坡缕石吸附理论的研究进展,列举了坡缕石在阴离子、阳离子和有机物吸附方面的研究成果,并提出了开发高附加值坡缕石吸附产品的研究方向。     

膨润土的改性及其对染料的吸附性能的试验研究

探讨了膨润土的改性机理、改性方法及其改性后对染料的吸附性能。以钙基膨润土为原料,系统地研究了pH值、活化时间及活化温度对膨润土改性的影响。通过对染料进行吸附试验确定出最佳改性条件,再将改性膨润土用于吸附染料实验,判断出pH值、活性白土用量以及吸附时间对染料吸附的影响。     

水热法改性凹凸棒石及其吸附性能的研究

分别以葡萄糖和淀粉为碳前驱体,凹凸棒石为原料,水热法制备有机改性凹凸棒石。通过扫描电镜(SEM)、红外吸收光谱(FTIR)、X射线衍射(XRD)以及吸附性能,考察葡萄糖和淀粉对凹凸棒石的形貌和性能的影响。结果表明,在制备改性凹凸棒石的过程中,碳前驱体对产物形貌和吸附性能有着明显的影响。葡萄糖分子在水热条件下碳化为直径50 nm碳颗粒,均匀负载在凹凸棒石表面,复合材料中含有─CH有机官能团;淀粉碳化为直径40~80 nm的碳球,不均匀的负载在凹凸棒石的表面,且表面含有─CH有机官能团。采用葡萄糖和淀粉为碳源的有机改性凹凸棒石对苯酚的去除率分别为70%和46%,分别是纯凹凸棒石对苯酚去除率的4倍和2.5倍。     

A sensitive and selective pyrosine sensor based on palygorskite–graphene modified electrode

Palygorskite–graphene composite was obtained by the electrochemical reduction of palygorskite–graphene oxide (GO), and the resulted palygorskite–graphene modified glassy carbon electrode (GCE) was used as the amperometric sensor for pyrosine determination. Compared to the graphene modified GCE, the detecting sensitivity of pyrosine was greatly improved at the palygorskite–graphene modified GCE. This was mainly attributed to the high adsorption capability of palygorskite. The effect of the mass ratio of GO to palygorskite was investigated, and the optimum mass ratio of GO to palygorskite was chosen as 2:1. The calibration curve was linear for pyrosine concentration from 21 to 598 μM, and the detection limit was as low as 5.98 nM (signal-to-noise ratio of 3). The palygorskite–graphene modified GCE also had satisfactory fabrication reproducibility, good determination precision and high detecting selectivity for pyrosine.