Papers by Keyword: Organophilic Bentonite

Abstract: The adsorption of organic pollutants from the waste water in the Beijing Shougang Coking Plant has been studied using bentonite modified by cetyl trimethyl ammonium bromide (CTMAB) in this experiment. The factors that affected the adsorbing capacity are amount of modifier, amount of sorbent, reaction time and grain size of organobentonite through a series of dynamic experiments. The experimental results show that under the conditions: the grain size of organobentonite 150µm, amount of organobentonite 10g•L^-1, modifier 5g and the adsorption time 60min, the removal efficiency of group components and polycyclic aromatic hydrocarbons (PAHs) from the waste water can reach 90% above.

Abstract: We selecte two bentonite products: activated clay and organo-bentonite, and introduce the related content of them like industrial applications, technology and raw materials of producting at the same time. After that, we choose the preparation processes of activated clay and organo-bentonite. Choose conditions of the prepared samples, arranging test methods by orthogonal test program, and preparing of the activated clay and organo-bentonite samples in accordance with the different test conditions. Finally, we draw this conclusion according to the test analysis and demonstration results. We propose the recommendations of the development of activated clay and organo-bentonite by Hongquan bentonite, pointing out that the shortcomings of this study and proposing pilot study of future.

Abstract: A new modified organo-bentonite using dithizone(D-O-bentonite) was used for preconcentration, separation and determination of silver(I) in natural water by flame atomic absorption spectrometry (FAAS). The experimental conditions for effective adsorption and elution of trace levels of silver (I) were optimized with respect to different experimental parameters. The influences of some common coexisting ions were also examined. The results show that the silver ion could be adsorbed on the D-O-bentonite. The adsorbed quantitively was affected by the pH value of medium and contact time. In the medium of pH 4-8, the contact time was 15 min, and capacity of the sorbent was 19.7 mg·g^-1. The silver(I) adsorbed on the sorbent could be completely eluated by using 1 mol·L^-1 HNO₃. The preconcentration factor is 100. The detection limit of the method for silver was 0.02 µg·L^-1. The method was applied to the pre-concentration/separation of silver in the environmental water with satisfactory results.

Abstract: Organophilic Bentonite / Paraffin composite phase change energy storage materials (OB/P PCM composite) were prepared by melting intercalation method. Under high temperature, no melt paraffin seep out from the PCM of organophilic bentonite/paraffin (OB/P) mass ratio is 2:1, which paraffin content is largest. Samples were tested by X ray diffraction (XRD), Scanning Electron Microscope (SEM), Differential scanning calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FTIR). Paraffin was well intercalated into layerd bentonite. Melting point and fussion heat of composite PCM with mass ratio2:1 are 45.7 °C and 68.7 kJ/kg, it can be added to solar energy.

Abstract: A new method for the determination of traces of mercury in environmental and biological samples is described. The present methodology combines determined using a hydride generation-atomic absorption spectrometry (HG-AAS) with pre-concentration/separation of the analyte on dithizone-anchored organobentonite (D-O-bentonite). Optimal experimental conditions for the adsorption of the Hg, including pH, contact time, eluent concentration and volume and co-existing ions have been studied. The result showed that the mercury could be adsorbed on the D-O-bentonite. The adsorbed quantitively was affected by the pH value of medium and contact time. In the medium of pH 5.0, the adsorption time was 15 min, and capacity of adsorption was 23.2 mg·g^-1. The mercury adsorbed on the sorbent could be completely eluated by using 3 mol·L^-1 HCl. The adsorption agent has been applied to the pre-concentration/separation of mercury in surface water and human hair samples with satisfied results.

Abstract: In this paper, a new method for the determination of bismuth in urine and tap water is described. The methodology combines determined using a hydride generation-atomic absorption spectrometry (HG-AAS) with pre-concentration of the bismuth on the modified organobentonite by dithizone (D-O-bentonite). Optimal experimental conditions for the adsorption and elution of the bismuth, including pH, contact time, eluent concentration, eluent volume and co-existing ions have been investigated. The result showed that the bismuth ion could be adsorbed on the D-O-bentonite. The adsorbed quantitive was affected by the pH value and contact time. In the medium of pH 5.0, the shaking time was 10 min, the adsorption capacity was 15.2 mg·g^-1. The bismuth adsorbed on the modified organobentonite by dithizone could be completely eluated by using 2 mol·L^-1 HNO₃. The method has been applied to the pre-concentration/separation of bismuth in the human urine and tap water samples with satisfied results.

Abstract: Composite photocatalysts, prepared by mechanical grinding TiO₂ with bentonite/ organobentonite, were applied in the dynamic photodegradation of gaseous toluene. A substrate enriched environment surround the loaded TiO₂ was formed by the adsorption of the added sorbents, leading to an increase in the degradation rate. The performance of composite catalysts was quite different in the initial and the long-term period of photocatalysis. The differences could be attributed to the adsorption properties of added sorbents related to adsorbility, hydrophilicity and diffusion feasibility, etc. The longer alkyl-chain of organobentonite formed a better partition phase resulting in an ideal adsorption capacity. However, as the alkyl-chain length increased, the diffusion path was segmentally clogged which seriously hindered the photocatalysis in the initial period. Although the adsorption capacity of original bentonite was quite small, the facility of diffusion changed it into the best performer in the initial period. Organobentonite with relatively short alkyl-chain conceived a little smaller adsorption capacity than the longer one. Moreover, the former one showed much more trending to diffuse the adsorbed toluene to catalyst. The long-term period of photocatalysis was also affected by the hydrophilicity of catalyst. Hence, the performance of organobentonites added composite catalyst mended a lot in the final degradation rate. Thus, organobentonite as 20DTAB with the advantage of large adsorption capacity and good diffusion feasibility is believed to be a promising carrier of photocatalys.

Abstract: Organophilic Bentonities clays are widely used for industrial purposes, as components of petroleum drilling fluids as well as in cosmetics, lubricants adhesives and paints. Most recent they have been used as fillers in polymer nanocomposites. In this work, three organophilic bentonitic clays from the distric of Boa Vista and one from Campina Grande, PB, Brazil, were synthesized and characterized. The four clays were treated with a quaternary chloride ammonium salt- dimethyl benzyl ammonium alkyl chloride (Dodigen 1611) provided by Chemco. The cation exchange and swelling capacities of the modified clays were determined and the clays were characterized by FTIR, Thermal Analysis (DTA, TGA) and X-ray diffraction. The results showed the modification of all four clays by the quaternary ammonium salt to be successful.