Papers by Keyword: Smectite

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Authors: Junichi Matsushita, Seong Ho Yang, Geum Chan Hwang
Abstract: The Na-bentonite with contained smectite was fabricated in order to observe their absorption and preservation about water. Absorption of fabricated specimens in the water and preservation of absorbed samples in the drying machine at 323 K was measured. It was obtained that absorption had been decreasing with increasing smectite. Absorption of As-received Na-bentonite was higher than absorption of As-received smectite. The preservation has been also decreased with increasing smectite was obtained. Na-bentonite with contained smectite were investigated the good absorption and preservation when the Na-bentonite containing smectite 5 mass %.
241
Authors: Junichi Matsushita, Seong Ho Yang, Geum Chan Hwang
Abstract: The Na-bentonite compact with absorbent polymer was fabricated in order to observe their absorption and preservation about water. Absorption of fabricated specimens in the water and preservation of absorbed samples in the drying machine at 323 K was measured. It was obtained that the absorption had been increasing with inhancing absorbent polymer. Absorption of As-received Na-bentonite was lower than absorption of As-received absorbent polymer. The preservation had been also increased with absorbent polymer was obtained. Na-bentonite compact with absorbent polymer ware investigated the good absorption and preservation when the Na-bentonite compact with absorbent polymer 40 mass %.
245
Authors: Zhen Wang, Ze Sheng Cheng, Yu Liu, Na Na Bo, Shu Ping Li
Abstract: The hydroxy-aluminum pillared bentonite(OH-Al-bent) and aluminum pillared bentonite(Al-bent) were synthesized and characterized by XRD and SEM analysis. The yield of products and the adsorbent capabilities for Cr(Ⅵ) from aqueous solution were investigated, and the optimal experimental conditions including adsorption time, reagent dosage, the initial concentration of Cr(Ⅵ) and PH that might influent the adsorption performance were also investigated. It was observed that the adsorption capabilities of OH-Al-bent was better than Al-bent. The efficiency of Cr(Ⅵ) removal were better when the dosage of the sorbent was higher. And a reagent dosage of 7g/L, adsorption time of 60min, PH of 4 were selected as an optimum conditions.
1037
Authors: C.L.V. José, Francisco Rolando Valenzuela-Díaz, Pedro M. Büchler
550
Authors: Wellington Siqueira Lima, André Luiz Fiquene de Brito, Meiry Glaúcia Freire Rodrigues, Mariaugusta Ferreira Mota, Marcílio Máximo Silva
Abstract: The clay types, kaolinite and smectite, are the most used industrially, mainly due to its sorption characteristics. There have been several attempts to improve the quality and characteristics of the clays, modifying them with different techniques. Two of the common techniques are thermal activation and acid activation. For acid activation, hydrochloric acid was used with a reaction time of 1 hour while the thermal activation the samples calcined at 300oC for 24 hours. This work aims to characterize the gray clay (supplied by Süd-Chemie LTDA) and Brasgel (provided by Bentonit), both in its natural form, as well as in the acid and thermal activation form (300°C). Natural and treated clays were characterized by X-ray Spectroscopy Energy Dispersive (EDX), X-ray diffraction (XRD) and nitrogen adsorption (BET). The results showed a reduction of impurities in the samples and did not comprise changes in the structure of the constituent minerals.
662
Authors: Bing Tao Liu, Guang Yu Zhu, Jia Yi Pu
Abstract: Due to its influence on iron corrosion and involvement in dechlorination reaction, the concentration of H+ is crucial to the reactivity and efficiency of nanosized Pd /Fe. In this study, PCP dechlorination by smectite-templated Pd/Fe was studied and the effect of pH on PCP dechlorination was investigated in detail. The reaction rate constant is critically dependant on the reaction pH over the range 6.0~10.0. The dechlorination rate increases rapidly with decreasing the reaction pH value when the pH is 6.0~8.0. The rate change is up to 3.346 folds with decreasing of per pH unit while it decreases down to 0.3338 when pH is in the range 8.0~10.0. The reductive efficiency of zero-valent iron (ZVI) was further investigated by spiking excess PCP in the reaction system. The maximal reaction efficiency of ZVI for PCP dechlorination attains to 78% when pH is 9.0. The difference between the dechlorination rate and reductive efficiency with respect to reaction pH suggest that ZVI could not be effectively utilized to reduce PCP under acidic condition.
3071
Authors: Jun Li Han, Han Zhong Jia, Cun Yi Song
Abstract: Due to its influence on iron corrosion and involvement in dechlorination reaction, the concentration of H+ (i.e. reaction pH) is crucial to the reactivity and efficiency of nanosized Pd0/Fe0. In this study, PCP dechlorination by smectite-templated Pd0/Fe0 was studied and the effect of pH on PCP dechlorination was investigated in detail. The reaction rate constant is critically dependant on the reaction pH over the range 6.0~10.0. When the pH is 6.0~8.0, the dechlorination rate constant () increases rapidly with decreasing the reaction pH value; the rate change is up to 3.346 folds with decreasing of per pH unit; while it decreases down to 0.3338 when pH is in the range 8.0~10.0. The reductive efficiency of zero-valent iron (ZVI) was further investigated by spiking excess PCP in the reaction system. The maximal reaction efficiency of ZVI for PCP dechlorination attains to 78% when pH is 9.0. The difference between the dechlorination rate and reductive efficiency with respect to reaction pH suggest that ZVI could not be effectively utilized to reduce PCP under acidic condition.
1490
Authors: Jill Manapat, Ivyleen Arugay, Johanna Michelle Ambait, Mitch Irene Galvan, Leslie Joy Diaz
Abstract: A novel technique that makes use of electrophoretic deposition (EPD) in upgrading the quality of Philippine clay, specifically for smectite recovery, was explored in this study. Focus was given on understanding the electrophoretic behavior of smectite and kaolinite to effectively control colloidal stability during EPD. Zeta potential measurements showed that pH has negligible effect on the electrophoretic mobility of smectite, but has an appreciable effect on the mobility of kaolinite with the isoelectric point (IEP) of kaolinite recorded around pH 5. Knowing this behavior, EPD of a 3.5wt% smectite-kaolinite slurry was carried out at pH 5 and pH 10. Separation of clay minerals was expected only at pH 5 where kaolinite is almost immobile. However, analysis of deposits using XRD showed some degree of separation (~60% smectite recovery) for both pH values when EPD was performed using stainless steel electrodes at a specific applied voltage and electrode gap, for twenty minutes, without stirring. Further investigation of EPD design is needed to improve smectite recovery.
280
Authors: Hideo Watanabe, Hideki Matsushima, Masayoshi Fuji, Minoru Takahashi
Abstract: Layered clay has been of great interest because of their nano-sized layer structure and hence intercalation and ion-exchange capacity to be used as a host material of composite with polymers and/or metals. In this study, smectite as a silicate-layered clay was easily exfoliated and dispersed into purified water, and was deposited onto a cupper plate for which dc voltage ranging from + 1.0 V to + 6.0 V was applied with respect to a counter platinum plate electrode. The cupper plate was pre-treated by chemical and chemical mechanical polishing (CP and CMP) prior to the electrophoretic deposition (EPD). The surface roughness of the substrate as well as the smectite film formed was characterized by an atomic force microscope (AFM). The thickness of smectite layer was estimated using an X-ray fluorescence (XRF) analysis as well as a scanning electron microscope (SEM) observation. The layer thickness can be described as a function of operational parameters such as applied voltage and operating time. Smooth smectite film with thickness ranging from 100 nm to 10 μm has been successfully fabricated onto the CMP cupper plate by the EPD method in this study.
195
Authors: Takanori Watari, Gosuke Shiraishi, Kohei Nagata, Toshio Torikai, Sachiko Furuta
2017
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