共查询到19条相似文献，搜索用时 134 毫秒
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以溴化十六烷基三甲铵为改性剂，对天然钙基膨润土进行有机化改性，系统地研究了改性剂用量以及钠化，热活化和酸活化对有机膨润土吸附苯酚、苯胺、苯、甲苯和二甲苯的影响，并初步探讨了有机膨润土与有机物间的作用机理。实验结果表明，改进剂用量是影响有机膨润土对有机物吸附性能的主要因素；改性剂用量相同时，钠化土的吸附效果明显好于直接改性的6.0%土，而热活化和酸活化对于有机膨润土吸附不同的有机物时影响程度也不同。应用有机膨润土建造垃圾填埋场防渗衬层具有一定的可行性。 相似文献
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采用不同添加量(1~4 mmol/g)的聚合羟基铝离子(Al13)柱撑改性膨润土,制得系列铝柱撑膨润土(Al13-Bent)。采用X射线衍射、热分析、N2吸脱附比表面积分析等表征分析了其结构特点,比较了不同添加量Al13-Bent对水中磷酸根与结晶紫的吸附性能。结果显示,随着Al添加量增大,Al13-Bent的比表面积增大,柱撑产物的底面间距在添加量为2 mmol/g后达到最大,稳定于1.9 nm左右。Al13-Bent对水中磷酸根的吸附效果好于原始膨润土,且随着Al含量增加而提高。Al13-Bent在低Al添加量下对水中结晶紫虽有较好的吸附能力,但其吸附性能相比于膨润土原土却有所下降。就其吸附机理来看,层间域内Al13离子表面羟基与层间阴离子促进了对阴离子含氧酸根的吸附;由于Al13柱撑后,层间可交换阳离子减少,导致对阳离子型染料的吸附性能下降。 相似文献
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以过硫酸钾为引发剂,通过水溶液聚合法制得了丙烯酸和丙烯酰胺的聚合物A。用聚合物A作为有机改性剂,采用混炼挤压法制备得到样品。用X射线衍射(XRD)、红外光谱(FT-IR)、扫描电子显微镜(SEM)等方法对其结构形貌进行研究。结果表明,其晶面间距由原来的1.269 nm增大到1.322 nm,有机基团进入层间,并且仍保持层状结构,成功制备出了有机改性膨润土。用有机改性膨润土配制钻井液,当其质量分数为4%时,浆液的粘度为5.5 mPa.s,滤失量为13 mL,润滑系数为0.13。与普通钠基膨润土钻井液相比,有机改性膨润土钻井液的滤失量和润滑系数均有较大幅度降低,并且改善了钻井液的流变性。 相似文献
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壳聚糖和PDMDAAC改性膨润土用于处理含油废水的研究 总被引：1，自引：0，他引：1
含油废水污染范围广,对人类和生态环境危害大。采用常规方法(如浮选法、絮凝法、电化学法、膜分离法和生物法)处理的除油率不高于91%,成本较高,因此急需开发一种高效低廉的吸附剂。膨润土是一种优良的吸附剂,但用其直接处理含油废水的效果较低。本文选用壳聚糖和PDMDAAC两种有机物作为改性剂,对钠基膨润土改性,使膨润土能有效地处理含油废水。通过实验比较了两种有机改性膨润土处理含油废水的最佳去除条件,探讨了表征对其吸附性能的影响。去油效果结果表明:壳聚糖改性膨润土的除油率可达87.8%,PDMDAAC改性膨润土的除油率可达89.3%,处理所需时间少于15 min;除油效率和处理时间都优于常规方法。吸附性能表征结果显示,两种改性剂均以负载的方式和钠基膨润土颗粒结合,吸附性能良好;相比而言,PDMDAAC改性膨润土的处理效果比壳聚糖改性膨润土更好。PDMDAAC应用于含油废水的处理,具有成本低、效率高、操作简单的特点,在含油废水处理领域具有较好的应用前景。 相似文献
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γ辐照对改性钠基膨润土影响的初步研究 总被引：1，自引：0，他引：1
为了确认γ辐照对改性钠基膨润土的影响,拓展高放地质处置缓冲材料性能评价范围,以内蒙古高庙子改性钠基膨润土为研究对象,利用红外光谱分析仪、同步热分析仪和X射线衍射仪分析了不同γ辐照剂量(1000、2000、3000、4000和5000 k Gy)对改性钠基膨润土性能和微观结构的影响。结果表明:在5000 k Gy大剂量γ辐照后,高庙子改性钠基膨润土中某些官能团发生了少量的化学转变,耐热性能有所提高,但对钠基膨润土中的层间水和吸附水影响不大;另外其微观结构变化不明显,只是晶胞尺寸有所减小;总体而言,高庙子钠基膨润土在大剂量γ辐照环境中稳定性是良好的。 相似文献
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为了提高蒙脱石对大分子物质的吸附性,利用邻菲罗啉可与过渡金属离子形成配合物的性质,用两种方法对蒙脱石加以改性。通过测定改性蒙脱石对染料的脱色性及分析XRD图,研究邻菲罗啉的配合物的生成方式对蒙脱石层间结构及吸附性能的影响,并探讨了改性蒙脱石的热稳定性。结果表明,邻菲罗啉能够进一步撑开层间含有过渡金属离子的蒙脱石片层,使层间距明显增大到1.76nm以上;采用过渡金属离子为先驱体,先插入蒙脱石层间、再原位生成配合物的两步法能获得既增大层间距、又提高有序度的良好效果;改性蒙脱石在400℃以下具有很好的热稳定性。 相似文献
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Aref Alshameri Alkhafaji R.Abood Chunjie Yan Akhtar Malik Muhammad 《Arabian Journal of Geosciences》2014,7(3):841-853
The bentonite deposit of Lahij Province, Yemen, has very promising commercial applications due to its mineralogy and physical and chemical properties. It was examined to determine its mineralogical composition, chemical and physical properties of the bentonite deposit, purity and sodium-exchanged bentonite. Modified bentonite was synthesized by exchanging cetyltrimethylammonium cations for inorganic ions on the bentonite and its adsorption properties for ammonium were characterized in batch experiments. Analytical methods were carried out to study the bentonite comprising X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy, chemical analysis and kinetic and isotherm models were also tested. The results have shown that the purification of bentonite resulted in a bentonite fractions of the total sample composed of montmorillonite and <5 % quartz. The XRD data showed that the interlayer spacing (d 001) of bentonite decreased from 15.3 to 12.5 Å and then increased to 19.7 Å. Moreover, high cation exchange capacity, good water absorption and high swelling capacity were also obtained. The results have shown that the modified bentonite was more effective than the natural bentonite for ammonium removal. In addition to that, pseudo-second-order kinetic model, Freundlich and the Langmuir models described the adsorption kinetics and isotherm well. It was concluded that Yemen (Alaslef) bentonite can be potential adsorbents for ammonium removal. 相似文献
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改变了传统制备铝盐改性膨润土工艺中原料的添加顺序,增强了膨润土的膨胀性能。对制备的铝盐改性膨润土进行SEM、XRD、粒径分布以及红外光谱表征,并与原料-钠基膨润土进行了对比,得到了改性的机理。最后,利用钠基膨润土和铝盐改性膨润土吸附硅酸盐的现象以及性能对铝盐改性膨润土进行了评估。结果表明：铝盐改性膨润土的制备方法较为简单,省去了传统工艺中加碱调节pH值,采用先将水浴钠基膨润土混合,再加改性剂的添加顺序,得到的铝盐改性的膨润土有很好的除硅效果,最高可达99%。 相似文献
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Synthesis and Photocatalytic Activity of Ti-pillared Bentonite 总被引：1，自引：0，他引：1
Ti-pillared bentonite has been successfully prepared using a modified method that can induce the transformation of TiO2 pillar from amorphous to anatase phase at a low temperature （150℃）. The value of d0.01 =1.94 nm obtained by Ti-pillared bentonite is larger than that of corresponding raw clay （1.56 nm）. Due to large numbers of Ti-pillars formed, the Ti-pillared bentonite shows an excellent ability in adsorbing Rhodamine B （RB）. The photocatalytic activity and kinetic equation are investigated by decomposing RB solution under the UV irradiation. It is found that the Ti- pillared bentonite shows super photocatalytic activity for the degradation of RB solution compared with the untreated bentonite and pure TiO2, and the kinetic equation of the degradation of RB solution is a 1.5-oder equation. 相似文献
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有机化膨润土对水中金属离子的吸附及其表征 总被引：1，自引：0，他引：1
通过正交实验研究了有机膨润土对水溶液中金属离子吸附的主要影响因素;将原矿和有机土进行了IR和XRD表征;测定了溶液酸度和溶液中金属离子浓度对有机膨润土吸附效果的影响;考察了有机膨润土的粒径和吸附次数对吸附效果的影响,以此论证新疆夏子街钠基膨润土及有机化膨润土对水溶液中各金属离子的吸附能力。实验结果表明:有机化膨润土对水溶液中Cr6 、Hg2 、Cu2 和Zn2 金属离子的去除率都比原土有显著提高;溶液的pH值对吸附效果影响较大;有机膨润土吸附量对数与Cr6 、Hg2 、Cu2 金属离子平衡浓度对数的吸附等温线近似成直线,符合吸附等温方程;金属离子浓度对有机膨润土吸附效果的影响趋势是Cr6 >Hg2 >Cu2 ;有机膨润土对金属离子吸附能力大小是Hg2 >Cu2 >Cr6 ,吸附速率大小是Cr6 >Hg2 >Zn2 。有机膨润土的粒径对吸附效果影响较小。 相似文献
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I. K. Chandra Y.-H. Ju A. Ayucitra S. Ismadji 《International Journal of Environmental Science and Technology》2013,10(2):359-370
The feasibility of natural bentonite and rarasaponin–bentonite for Evans blue removal from aqueous solution was studied. Rarasaponin is a natural surfactant obtained from Sapindus rarak DC was used as modifying agent for natural bentonite modification. Adsorption experiments were conducted in a batch system at various temperatures. Several temperature-dependent isotherm models (Langmuir, Freundlich, Sips and Toth) were used to represent equilibrium data. It was found that Toth model represents the adsorption equilibrium data better than other models. Kinetic data were best represented by the pseudo-first order model. The controlling mechanism of the adsorption of Evans blue onto natural bentonite and rarasaponin–bentonite was physical adsorption. 相似文献
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M. Urík M.Sc. P. Littera J. >Sevc Ph.D. M. Kolen>cík S. >Cer>nanský M.Sc. 《International Journal of Environmental Science and Technology》2009,6(3):451-456
Arsenic is a ubiquitous element in the environment and occurs naturally in both organic and inorganic forms. Under aerobic condition, the dominant form of arsenic in waters is arsenate, which is highly mobile and toxic. Arsenic poisoning from drinking water remains a serious world health issue. There are various standard methods for arsenic removal from drinking waters (coagulation, sorption, ion-exchange reactions or methods of reverse osmosis) and alternative methods, such as biosorption. Biosorption of arsenic from natural and model waters by native or chemically modified (with urea or ferric oxyhydroxides) plant biomass prepared from sawdust of Picea abies was studied. The kinetic of the adsorption process fitted well the pseudo second order adsorption model and equilibrium was achieved after 2 h. The results showed that biosorption was well described by both Langmuir and Freundlich isotherms. The maximum biosorption capacity of the sawdust modified with ferric oxyhydroxides, evaluated by Langmuir adsorption model, was 9.259 mg/g, while the biosorption capacity of unmodified biosorbent or biosorbent modified with urea was negligible. The adsorption capacity is comparable to results published by other authors, suggesting that the prepared chemically modified biosorbent has potential in remediation of contaminated waters. 相似文献