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41.
Tomohito Kameda Kazuya Horikoshi Shogo Kumagai Yuko Saito Toshiaki Yoshioka 《中国化学工程学报》2021,28(12):2993-3001
In this paper, we propose that the urinary toxins from the wastewater be adsorbed on an adsorbent such as spherical activated carbon and the latter be regenerated by subjecting it to high temperatures to recycle activated carbon and also to recycle the water used in dialysis. We studied the adsorption of artificial waste dialysate, which is a mixed solution of urea, creatinine, and uric acid, and the separate solutions for each of these and found that their extents of adsorption onto the spherical activated carbon material were nearly identical. The amount of adsorption was approximately 1.4 mg·g-1 for urea, 18 mg·g-1 for creatinine, and 20 mg·g-1 for uric acid. The urea, creatinine, and uric acid adsorbed onto the spherical activated carbon decomposed on heat treatment at 500℃, and the adsorption capacity of the spherical activated carbon was regenerated. Our study successfully demonstrated that the spherical activated carbon can be recycled in the waste dialysate treatment process. 相似文献
42.
Sn-incorporated folded sheets mesoporous materials (Sn-FSM-16) with various contents of Sn were synthesized by using a mixture of water glass, SnCl4 and NaOH as starting materials. Hexadecyltrimethyl-ammonium chloride (surfactant) was used to intercalate into the layered silicate. The reaction process was followed by measurements of XRD patterns of intermediates. The Sn-FSM-16 was formed via the following mechanism: (1) layered silicates such as - - and -Na2Si2O5 were formed as intermediates by the calcination of the mixture of the starting materials; (2) the surfactant was intercalated into the layered silicates; (3) the surfactant-silicate complex with hexagonal structure was obtained as a precursor of Sn-FSM-16; (4) the precursor was calcined to decompose the surfactant in the interlayer and was changed to Sn-FSM-16. The structural aspect of Sn in Sn-FSM-16 was studied by XPS profiles of Sn 3d
5/2 and Si2p, 29 Si MAS NMR and FTIR. The content of Sn in Sn-FSM increased with increasing concentrations of both Sn and NaOH in the starting materials. The surface area of Sn-FSM-16 decreased with an increase of Sn content in Sn-FSM (1160–620 m2/g). 相似文献
43.
Kazuhiko Takeuchi Taka-aki Hanaoka Takehiko Matsuzaki Yoshihiro Sugi Shigeto Ogasawara Yoshimoto Abe Takahisa Misono 《Catalysis Today》1994,20(3):423-435
An in situ diffuse reflectance FT-IR technique was employed to investigate the active surface species and the reaction mechanism of the oxygenate formation in the vapor phase hydroformylation of ethene on Co/SiO2 promoted with various noble metals such as Ir, Rh, Pt, Re, Ru, and Pd. Co(A)/SiO2 and Ir(CO)/SiO2 which were derived from cobalt(II) acetate and Ir4(CO)12, respectively, were quite inactive in the reaction, and showed only quite small peaks of adsorbed CO under the conditions of 1.1 MPa of C2H4/CO/H2 at 298 K. In contrast, Co(A)-Ir(CO)/SiO2, which were very active in the reaction, exhibited strong absorption bands of linear and bridged CO species. At 423–463 K, propanal adsorbed on the catalyst and acyl species which is suggested as the intermediate for the formation of propanal were also observed on this catalyst. By exposing CO preadsorbed on this catalyst to C2H4/H2 at 289 K and 0.1 MPa, the intensity of the linear CO band decreased, and the bands of propanal and acyl species emerged simultaneously, whereas that of the bridged CO band remained constant after the initial drop. These results suggested that the oxygenates are formed via the CO insertion into adsorbed ethyl species, and linear CO species plays a major role in the CO insertion on these noble metal-promoted cobalt catalysts. 相似文献
44.
Masayuki Nogami Yoshihiro Abe Ayako Kato 《Journal of the American Ceramic Society》1995,78(4):1066-1070
Silica glasses doped with small-sized CdSx -Se1-x crystals were prepared by the sol-gel method. Gels synthesized by the hydrolysis of Si(OC2 H5 )4 , in the presence of CdSeO4 with NH4 SCN dissolved in HNO3 or NH4 OH, were heated in H2 -N2 atmosphere. The pH value of solutions for CdSeO4 and NH4 SCN primarily determined the fraction of anions in CdSx Se1-x crystals. The anion content in crystals was dependent on the pH value of the solvent and/or heat-treatment temperature, and the sulfur fraction changed from 0.1 to 0.6. The optical absorption spectra were red-shifted as the selenium content and the crystal size increased, and the emission spectra showed a sharp band near the absorption edge position and a broad tail extending into the long wavelength. The optical band gap energies increased reciprocally proportional to the square of the crystal size. 相似文献
45.
N,N'- Unsymmetrical dialkyl-3,4:9,10-perylenebis(dicarboximide)s (in which alkyl = methyl, ethyl, propyl, butyl, isobutyl, pentyl, hexyl and octyl) were prepared by the condensation of N-alkyl-3,4:9,10-perylene-tetracarboxylic monoanhydride monoimide with the appropriate alkyl-amines. The properties of these derivatives as pigments were tested and their thermal stability measured. 相似文献
46.
A high-performance liquid chromatographic method, using post-column detection with diphenyl-1-pyrenyl-phosphine (DPPP), was
developed for the quantitative and qualitative determination of isomeric lipid hydroperoxides (OOH). The OOH eluted from a
normal-phase column were passed through a photodiode array detector and then mixed with DPPP solution in a reaction coil heated
at 80°C. DPPP oxide formed by the reaction with OOH was determined by monitoring the fluorescence intensity at 380 nm and
excitation at 352 nm. The conjugated diene OOH (13-cis, trans- and 9-cis, trans-OOH) and nonconjugated OOH (12-cis-trans- and 10-cis, trans-OOH) from photosensitized oxidation of methyl linoleate were determined in a molar ratio of 31∶29∶19∶21, respectively. However,
only the two conjugated hydroperoxides were detected by ultraviolet absorption at 234 nm. Further applications were carried
out for the determination of OOH of methyl oleate and methyl linolenate. This method proved to be useful for the determination
of the OOH containing both conjugated and nonconjugated diene structures. 相似文献
47.
Ken Shimomai Noboru Higashida Toshiaki Ougizawa Takashi Inoue Bernd Rudolf Jörg Kressler 《Polymer》1996,37(26):5877-5882
The miscibility of poly(methyl methacrylate) (PMMA) and styrene-acrylonitrile random copolymers (SAN) blends was investigated on the basis of the Flory—Orwoll—Vrij equation of state theory. To obtain the equation of state parameters (P*, V*sp, T*: characteristic parameters), the pressure—volume—temperature (PVT) behaviour was measured for PMMA and a series of SANs with various acrylonitrile contents. The exchange energy parameter Xij was also calculated by fitting the theory to some phase diagrams of PMMA/SAN blends. The Flory—Huggins interaction parameter χ was separated into two contributions based on the equation of state theory for mixtures: the exchange energy term χinter and the free volume term χfree. Both the temperature and copolymer composition dependences of χinter and χfree were estimated by calculations using the equation of state parameters. There exists a region in which χinter is negative, leading to a miscibility window in PMMA/SAN blends. However, the immiscibility at high temperatures in the blends cannot be explained only by χinter; it is caused by the free volume contribution, χfree. The miscibility window behaviour in PMMA/SAN blends may be explained within the framework of the equation of state theory. 相似文献
48.
Tsugio Sato Kenji Dosaka Toshiaki Yoshioka Akitsugu Okuwaki Kazuo Torii Yoshiro Onodera 《Journal of the American Ceramic Society》1992,75(3):552-556
Amorphous CeO2 –ZrO2 gels were prepared by coprecipitation in ammonia solutions. The onset of crystallization of the gels, from calcining in air, was 420°C, while 200° to 250°C in the presence of water and organic solvents such as methanol and ethanol. The sintering behaviors of CeO2 –ZrO2 powders were sensitive to the crystallizing conditions, since hard agglomerates formed when the precipitated gels were crystallized by normal calcination in air, whereas soft agglomerates formed when they were crystallized in water or organic solvents. CeO2 –ZrO2 powders crystallized in methanol and water at 250°C were sintered to full theoretical density at 1150° and 1400°C, respectively, whereas that crystallized by calcination in air at 450°C was sintered to only 95.2% of theoretical density, even at 1500°C. 相似文献
49.
A new Ag/Al2O3 catalyst for removing NOx in lean exhaust gas was developed. Oxidized Ag/Al2O3 catalyst is highly active for reduction of NOx with ethanol and propene, whereas reduced Ag/Al2O3 catalyst is less active for these reactions. Selectivity to N2 is also high on the oxidized Ag/Al2O3 compared to that on the reduced Ag/Al2O3. XRD and SEM studies of these two types of Ag catalysts suggest that oxidation induces an interaction between Ag and the
support, where the particles are grown in large size. In contrast, the metallic Ag particles are finely dispersed by the reduction
process. Although dispersion of Ag particles is decreased by the oxidation process, the catalytic activity is increased. This
suggests that the Ag-alumina sites created in the high temperature oxidizing environment are active in catalytic reduction
of NOx.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
50.
Carbon materials are often used as catalyst supports, and for catalysts in electrodes of a polymer electrolyte fuel cell, carbon black has been used. Recently, it was found, however, that activated carbon could replace carbon black and besides, significantly improve the activity of the electrode catalyst layer for oxygen reduction. In the present study, to optimize the pore structure of activated carbon for further activity improvement, the influence of the pore structure on the activity was investigated using activated carbon of various specific surface areas and mean pore diameters. A catalyst layer was formed from activated carbon loaded with platinum and a polymer electrolyte. The activity of the layer was measured in an oxygen-saturated perchloric acid solution, supporting the layer on a rotating glassy carbon disk electrode. We found that increases in the specific surface area and mean pore diameter increased the activity and that the latter was more effective than the former mainly due to the enhanced mass-transfer in the pores; the catalyst layer formed from activated carbon with the largest mean pore diameter was the most active. Unless pores excessively develop and lose connections between particles, a large pore diameter is therefore desired for the fuel cell electrodes. 相似文献