The Experts below are selected from a list of 71250 Experts worldwide ranked by ideXlab platform

Masahiro Goto - One of the best experts on this subject based on the ideXlab platform.

  • emulsion Liquid Membrane extraction of silver from photographic waste using tetramethylthiuram disulfide tmtds as a mobile carrier
    Journal of Applied Membrane Science & Technology, 2017
    Co-Authors: N. Othman, Hanapi Mat, Chan Kit Hie, Chiong Tung, Masahiro Goto
    Abstract:

    The recovery of precious metals such as silver from photographic wastes is required in order to save raw materials and to protect the environment from dispersed compound, especially heavy metals. For that matter, several technologies have been used such as precipitation, electrolytic, and ion exchange processes which offer some advantages as well as drawbacks over others. Recently, emulsion Liquid Membrane extraction has been recognized to be a potential process for industrial wastes treatment and recovery of heavy metals. This process has the ability to selectively separate and rapidly concentrate metals through its very thin layer Liquid Membrane which has a large interfacial area. An attempt was made to recover silver from Liquid photographic wastes using tetramethylthiuram disulfide as a mobile carrier. The important variables affecting the emulsion Liquid Membrane (ELM) process including residence time, surfactant concentration, carrier concentration, level of agitation and phase ratio between emulsion and feed phase were investigated. The results showed that tetramethylthiuram disulfide is selective towards silver (>80%) compared to other metals in the photographic waste. The highest silver extraction is obtained using 0.05 M tetramethylthiuram disulfide, 3% (w/v) Span 80, 300 rpm stirring speed, 1.0 M thiourea in 0.1 M HCl stripping agent, 1:3 of treat ratio, and toluene as the diluent.

  • co2 separation facilitated by task specific ionic Liquids using a supported Liquid Membrane
    Journal of Membrane Science, 2008
    Co-Authors: Shoji Hanioka, Tatsuo Maruyama, Tomohiro Sotani, Masahiro Teramoto, Hideto Matsuyama, Kazunori Nakashima, Misa Hanaki, Fukiko Kubota, Masahiro Goto
    Abstract:

    Abstract We report a supported Liquid Membrane (SLM) based on a task-specific ionic Liquid to achieve the selective and facilitated CO2 transport through the Membrane. The prepared SLM facilitated by the amine-terminated ionic Liquid showed high selectivity and high stability (more than 260 days) for CO2 separation from the CO2/CH4 gas mixture.

  • enzyme facilitated enantioselective transport of s ibuprofen through a supported Liquid Membrane based on ionic Liquids
    Chemical Communications, 2003
    Co-Authors: Eijiro Miyako, Tatsuo Maruyama, Noriho Kamiya, Masahiro Goto
    Abstract:

    Coupling lipase reactions with a supported Liquid Membrane (SLM) based on ionic Liquids showed facilitative and selective permeation of (S)-ibuprofen through the SLM, indicating successful optical resolution of a racemic mixture using the enzyme-facilitative SLM.

  • Liquid Membrane transport of amino acids by a calix 6 arene carboxylic acid derivative
    Journal of Membrane Science, 2003
    Co-Authors: Tatsuya Oshima, Katsutoshi Inoue, Shintaro Furusaki, Masahiro Goto
    Abstract:

    Calix[6]arene hexacarboxylic acid was found to be a useful carrier for transporting amino acids through a Liquid Membrane. The calix[6]arene, which has a cyclic structure to include a guest molecule of the amino acid ester and bears six ionizable carboxylic acids to contribute electrostatic interaction, exhibited a high transport efficiency compared to its monomer analog and the other calix[n]arene derivatives. The novel carrier successfully transported hydrophobic amino acid esters from the feed phase to the receiving phase. The transport rate could be controlled by changing the pH gradient between the feed and receiving aqueous phases because the complexation proceeds by a proton-exchange mechanism. Furthermore, an optical resolution system was constructed by applying an enantioselective enzymatic reaction for a chiral separation of the amino acids. In the enzyme reaction, the l-form ester was selectively hydrolyzed to the free amino acid. The free amino acid hydrolyzed was not transported, while the unhydrolyzed d-form ester effectively moved to the receiving phase through the Liquid Membrane containing the calix[6]arene as a mobile carrier.

Kun Huang - One of the best experts on this subject based on the ideXlab platform.

  • instability behavior of bubble supported organic Liquid Membrane in extraction of low concentration rare earths from in situ leaching solutions of ion adsorption ores
    Minerals Engineering, 2020
    Co-Authors: Jie Liu, Kun Huang, Wenqian Liu, Zhenmin Zhao, Huizhou Liu
    Abstract:

    Abstract Gas bubble supported organic extractant Liquid Membrane exhibits a promising potential in enhanced extraction and separation of low-concentration rare earths from the in-situ leaching solutions of ion-adsorption ores. However, instability of organic Liquid Membrane on the surface of gas bubbles might result in dissolution loss of organic extractant in the flowing-out aqueous raffinates and bring serious organic pollution if the raffinates are recycled for re-leaching of rare-earth ores. The present work focuses on the mechanism of the instability of organic extractant P507 Liquid Membrane on the surface of bubbles during rare-earth extraction. Various effects, including volume flow rate of aqueous feed solution, initial aqueous pHs and concentrations of co-existing impurity ions, saponification degree of P507 and pre-loaded concentration of rare earths in organic phase, on the stability of organic Liquid Membrane are discussed. Experimental results reveal that the stability of organic Liquid Membrane depends on three kinds of forces exerting on the surface of bubbles, i.e., the shear force Fs, the interface tension Ft and the dispersion force Fd. The occurrence of Ft and Fd are benefit for the stability, but Fs is not. The competition of the two component forces of Fs respectively with Ft and Fd will result in instability of organic Liquid Membrane and an increase in the concentration of total organic phosphorus in the flowing-out raffinates. The present work provides a theoretical basis about how to control the stability of organic extractant Liquid Membrane on the surface of gas bubble. Based on the suggested new technique by bubble supported organic Liquid Membrane extraction, a green and environmentally friendly strategy is suggested for replacing the traditional ammonium bicarbonate precipitation to extract low-concentration rare earths from in-situ leaching solutions of ion-adsorption ores.

  • chemical reaction driven spreading of an organic extractant on the gas water interface insight into the controllable formation of a gas bubble supported organic extractant Liquid Membrane
    Langmuir, 2019
    Co-Authors: Kun Huang
    Abstract:

    The extraction and recovery of low-concentration valuable metals from various complex aqueous solutions or industrial waste waters have attracted extensive interests in recent years. In our previous works, we suggested a novel technique called bubbling organic Liquid Membrane extraction by spreading and covering an organic extractant with extremely small volume on the surface of gas bubbles to form a layer of the gas bubble-supported organic Liquid Membrane for selective extraction and enrichment of low-concentration targets from dilute aqueous solutions. It was found that for successfully performing the bubbling organic Liquid Membrane extraction, a prerequisite is knowing how to control the formation of a stable organic Liquid Membrane covered on the surface of gas bubbles. However, once the organic extractant starts to spread on the surface of gas bubbles, the extraction chemical reaction at the interface between the organic extractant Liquid Membrane and the rare-earth aqueous solution will occur. In ...

  • extraction of rare earths using bubbling organic Liquid Membrane with un saponified p507
    Hydrometallurgy, 2018
    Co-Authors: Jie Liu, Kun Huang, Wenqian Liu, Weiyuan Song, Huizhou Liu
    Abstract:

    Abstract Extraction and enrichment of low-concentration rare earths from the in-situ leaching solutions of ion-absorbing type rare-earth ores using bubbling organic Liquid Membrane with un-saponified P507 was investigated. Experimental results revealed that saponification of P507 extractant are unnecessary for extraction of rare earths using bubbling organic Liquid Membrane. The equilibrium pH of the aqueous solutions flowing out from the extraction column would not decrease obviously, because the total volume of un-saponified P507 contacting with the aqueous phase in the column was very small, and the aqueous-to-organic phase ratios could be very large. Therefore, the loading capacity of rare-earth ions in the organic phase have no obvious changes, compared to that using saponified P507. Scale-up experiments in the pilot-scale columns connected in cascade for continuous countercurrent extraction of low-concentration rare earths about 100 mg/L in the leaching solutions demonstrated that, the final residual concentrations of rare earths remained below 3.0 mg/L, while total recovery of rare earths after extraction and stripping processes could reach above 90%. Bubbling organic Liquid Membrane extraction is in fact an interfacial chemical reaction of rare-earth ions with un-saponified P507 adsorbing at the surface of organic Liquid Membrane. During countercurrent extraction processes, shearing interaction of the aqueous solutions with dispersed organic bubbles rising in the extraction column would result in continuous exposure of fresh surface of organic bubbles, which is a main driving force to promote the mass transferring and enrichment of rare-earth ions into the organic Liquid Membrane layer.

  • enrichment of low concentration rare earths from leach solutions of ion adsorption ores by bubbling organic Liquid Membrane extraction using n1923
    ACS Sustainable Chemistry & Engineering, 2017
    Co-Authors: Jie Liu, Kun Huang, Huizhou Liu
    Abstract:

    A new bubbling organic Liquid Membrane extraction using primary amine N1923 at large aqueous-to-oil phase ratios was suggested to extract and enrich extremely low concentration rare earths from the acidic sulfate leach solutions of ion-absorbing type rare-earth ores. It was revealed that bubbling organic Liquid Membrane extraction was in fact an interfacial chemical reaction of organic extractant molecules absorbing at the surface of the organic Liquid Membrane supported by gas bubbles with the target metal ions in the aqueous solutions. Rare earths with a concentration about 100 mg/L can be extracted selectively and enriched efficiently into the organic extractant Liquid Membrane layer covered on the surface of dispersed gas bubbles. However, Al in leach solutions was not extractable and remained in the raffinates, due to a kinetic nonequilibrium separation behavior of rare earths and Al on the surface of the organic Liquid Membrane. It was the differences in reaction rate of rare earths and Al with prim...

Katsutoshi Inoue - One of the best experts on this subject based on the ideXlab platform.

  • Liquid Membrane transport of cytochrome c using a calix 6 arene carboxylic acid derivative as a carrier
    Journal of Membrane Science, 2008
    Co-Authors: Tatsuya Oshima, Yuka Shikaze, Akinori Suetsugu, Yoshinari Baba, Keisuke Ohto, Katsutoshi Inoue
    Abstract:

    Abstract The present study examined the Liquid Membrane transport of the cationic protein cytochrome c , using the macrocyclic compound calix[6]arene, which is a carboxylic acid derivative, as a carrier. The transport rate was governed by carrier concentration and the pH gradient between the feed and the receiving phases, as well as the salt concentration in the aqueous phases. Transport of cytochrome c was examined using a series of calix[ n ]arene carboxylic acid derivatives ( n  = 4, 6 and 8). Cytochrome c successfully permeated Membranes in the presence of the calix[6]arene derivative. Liquid Membrane separation of cytochrome c from a mixture of cationic proteins was demonstrated under optimal conditions. Cytochrome c was selectively extracted by the calix[6]arene carboxylic acid derivative and 77% of the extracted cytochrome c was recovered into the receiving phase. In this Liquid Membrane system, which discriminates between the number of lysine residues on the surface of proteins, cationic proteins with similar molecular weights and p I s were separated with macrocyclic compounds.

  • Liquid Membrane transport of amino acids by a calix 6 arene carboxylic acid derivative
    Journal of Membrane Science, 2003
    Co-Authors: Tatsuya Oshima, Katsutoshi Inoue, Shintaro Furusaki, Masahiro Goto
    Abstract:

    Calix[6]arene hexacarboxylic acid was found to be a useful carrier for transporting amino acids through a Liquid Membrane. The calix[6]arene, which has a cyclic structure to include a guest molecule of the amino acid ester and bears six ionizable carboxylic acids to contribute electrostatic interaction, exhibited a high transport efficiency compared to its monomer analog and the other calix[n]arene derivatives. The novel carrier successfully transported hydrophobic amino acid esters from the feed phase to the receiving phase. The transport rate could be controlled by changing the pH gradient between the feed and receiving aqueous phases because the complexation proceeds by a proton-exchange mechanism. Furthermore, an optical resolution system was constructed by applying an enantioselective enzymatic reaction for a chiral separation of the amino acids. In the enzyme reaction, the l-form ester was selectively hydrolyzed to the free amino acid. The free amino acid hydrolyzed was not transported, while the unhydrolyzed d-form ester effectively moved to the receiving phase through the Liquid Membrane containing the calix[6]arene as a mobile carrier.

Tatsuya Oshima - One of the best experts on this subject based on the ideXlab platform.

  • Liquid Membrane transport of cytochrome c using a calix 6 arene carboxylic acid derivative as a carrier
    Journal of Membrane Science, 2008
    Co-Authors: Tatsuya Oshima, Yuka Shikaze, Akinori Suetsugu, Yoshinari Baba, Keisuke Ohto, Katsutoshi Inoue
    Abstract:

    Abstract The present study examined the Liquid Membrane transport of the cationic protein cytochrome c , using the macrocyclic compound calix[6]arene, which is a carboxylic acid derivative, as a carrier. The transport rate was governed by carrier concentration and the pH gradient between the feed and the receiving phases, as well as the salt concentration in the aqueous phases. Transport of cytochrome c was examined using a series of calix[ n ]arene carboxylic acid derivatives ( n  = 4, 6 and 8). Cytochrome c successfully permeated Membranes in the presence of the calix[6]arene derivative. Liquid Membrane separation of cytochrome c from a mixture of cationic proteins was demonstrated under optimal conditions. Cytochrome c was selectively extracted by the calix[6]arene carboxylic acid derivative and 77% of the extracted cytochrome c was recovered into the receiving phase. In this Liquid Membrane system, which discriminates between the number of lysine residues on the surface of proteins, cationic proteins with similar molecular weights and p I s were separated with macrocyclic compounds.

  • Liquid Membrane transport of amino acids by a calix 6 arene carboxylic acid derivative
    Journal of Membrane Science, 2003
    Co-Authors: Tatsuya Oshima, Katsutoshi Inoue, Shintaro Furusaki, Masahiro Goto
    Abstract:

    Calix[6]arene hexacarboxylic acid was found to be a useful carrier for transporting amino acids through a Liquid Membrane. The calix[6]arene, which has a cyclic structure to include a guest molecule of the amino acid ester and bears six ionizable carboxylic acids to contribute electrostatic interaction, exhibited a high transport efficiency compared to its monomer analog and the other calix[n]arene derivatives. The novel carrier successfully transported hydrophobic amino acid esters from the feed phase to the receiving phase. The transport rate could be controlled by changing the pH gradient between the feed and receiving aqueous phases because the complexation proceeds by a proton-exchange mechanism. Furthermore, an optical resolution system was constructed by applying an enantioselective enzymatic reaction for a chiral separation of the amino acids. In the enzyme reaction, the l-form ester was selectively hydrolyzed to the free amino acid. The free amino acid hydrolyzed was not transported, while the unhydrolyzed d-form ester effectively moved to the receiving phase through the Liquid Membrane containing the calix[6]arene as a mobile carrier.

Guibin Jiang - One of the best experts on this subject based on the ideXlab platform.

  • continuous flow Liquid Membrane extraction a novel automatic trace enrichment technique based on continuous flow Liquid Liquid extraction combined with supported Liquid Membrane
    Analytica Chimica Acta, 2002
    Co-Authors: Jingfu Liu, Jingbo Chao, Guibin Jiang
    Abstract:

    Combining the continuous flow Liquid-Liquid extraction (CFLLE) and supported Liquid Membrane (SLM) extraction, a novel aqueous-aqueous extraction technique that we termed continuous flow Liquid Membrane extraction (CFLME) is developed for trace-enrichment. The analyte was firstly extracted into the organic phase in the CFLLE step, then transported onto the organic Liquid Membrane that formed on the surface of the micro porous Membrane of the SLM equipment. Finally, it passed through the Liquid Membrane and was trapped by the acceptor. Aspects related to CFLME were studied by using dichloromethane as Liquid Membrane, and sulfonylurea herbicides as model compounds. An enrichment factor of over 1000 was obtained when 10 mug l(-1) of MSM was enriched for 120 min by this technique. The drawbacks of only a few organic solvents can be selected as Liquid Membrane with a limited lifetime in SLM operation was overcome. In this CFLME method, almost all solvents that used in the conventional Liquid-Liquid extraction (LLE) can be adopted and the lifetime of Liquid Membrane is no longer a problem. (C) 2002 Elsevier Science B.V. All rights reserved.

  • automatic trace enrichment of bisphenol a by a novel continuous flow Liquid Membrane extraction technique
    Journal of Separation Science, 2001
    Co-Authors: Jingfu Liu, Jingbo Chao, Meijuan Wen, Guibin Jiang
    Abstract:

    Bisphenol A was enriched by a novel continuous flow Liquid Membrane extraction technique, which is based on the combination of continuous flow Liquid-Liquid extraction and a supported Liquid Membrane. Related parameters such as flow rates, Liquid Membrane solvents, and pH of donor and acceptor were optimized. Using dichloromethane as Liquid Membrane, over 200-fold enrichment of 50 mug L-1 BPA was obtained after a 40-min enrichment time. The major advantages of this technique are that it provides a relatively high enrichment factor, freedom of choice and long term stability of the Liquid Membrane, much lower consumption of organic phase, typically 0.05 mL min(-1), scope for full automation, and easy on-line coupling to various detectors.