深海粘土沉积物组份环境矿物学属性的初步研究.doc

深海粘土沉积物组份环境矿物学属性的初步研究 利用X射线衍射仪XRD、透射电子显微镜TEM、高分辨率透射电子显微镜HRTEM、X射线能谱仪EDS、选区电子衍射SAED、傅立叶红外变换光谱仪FTIR、比表面及孔径分析仪SAA, N2-BET等手段对来自北太平洋的深海粘土沉积物组份及其CTMAB/DTAB有机复合体进行表征,并对照研究了其对苯胺、苯酚及对氨基苯磺酸溶液的吸附行为。研究结果表明,CTMAB/DTAB有机阳离子随机进入可膨胀类矿物层间并使其有效层间域增大。XRD、HRTEM及FTIR可提供有机分子进入层间的直接证据。HRTEM及SAED研究显示,有机复合体的晶体结构未发生改变,但出现了更多的活性中心。在不同密度堆积状态下,有机阳离子在层间的排列方式存在差异。N2-BET的相关研究表明有机粘土复合体的外比表面积较原土有不同程度的减小,但介孔比表面积和总体积较原土有所增加,且孔径有集中分布的趋势。等温吸附脱附曲线上的B类滞后回环揭示深海粘土及其有机复合体含有丰富的介孔,且具平行壁狭缝状结构。吸附实验表明,有机复合体的吸附性能较原土有很大提高。在不大于5倍CEC的条件下,深海粘土复合体对实验浓度范围内的有机污染物的去除能力随有机阳离子负载量的增大而加强,且对极性溶液的吸附能力远大于非极性溶液。有机深海粘土沉积物组份对目标污染物吸附性能的提高可归结为因有机相的加入而增强的线性分配作用和大于有效孔径的孔隙的增多而加强的对目标污染物的截留效应。0.34nm可以视为吸附剂深海粘土截留具有单个苯环的有机污染物的最小有效孔径。相比较,硅质粘土型有机粘土复合体的环境属性优于含硅质粘土型有机粘土复合体 X-ray diffractionXRD, transition electronic microscopeTEM, high resolution transition electronic microscopeHRTEM, X-ray energy dispersive systemEDS, selected area electronic diffractionSAED, Fourier trans infrared spectroscopy FTIR and surface area applianceSAA were employed to characterize the clay sediment fraction from the North Pacific and its organo-complex modified by CTMAB/DTAB. Their adsorption behavior on phenol, aniline and P-aminobengene sulponite acid anhydrous were also comparatively studied. All the study indicated that the organic ions intercalated into the layers randomly and make them expanded. The crystal structures of the organo-clay had not been changed, but more active centers occurred by such modification. The arrangement of the organic ions differed with their different stack density in the layer. Compared with the unmodified clay fraction, the external surface area of organo-complex decreased, but the quantity of mesopores and total volume of pore increased. Pore diameter seemed to distribute in narrower scope after modified by organic ions. From the adsorption-desorption isotherms, we could conclude that the deep-sea clay fraction and its organo-clay complex showed hysteresis loopType B, indicating the pore of flat plate slit shape, with large quantities of mesopores. Results from the adsorption experiments showed that the organo-complex had higher ability to absorb object pollutants. Within five times of loadings of CEC, the adsorption ability of organo-clay increased with more organic ions exchanged. The organo-complex showed much better adsorptive ability in polar solvent than in nonpolar solvent. The better adsorption perance of the organo-clay could be attributed to the increased partition caused by the intercalated CTMAB and higher retention ability of the object organic pollutants by the increased efficient pore diameter after organic modification. Diameter of 0.34nm could be considered as the minimum effective pore diameter to hold back the organic pollutant with one single benzene ring. As a whole, typical siliceous clay showed better environmental properties than siliceous-bearing clay.;