• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.1 no.1
• /
• pp.43-48
• /
• 2000

Upon the Preparation of activated carbon fiber(ACF) using chemical activation method and vapour activation method, the fiber obtained from the vapour activation method shows excellent surface Properties. The preparation of antibacterial activated carbon fiber was tried to open the new areas in application of carbon materials. The BET specific surface area and the average pore radius of the antibacterial ACFs were in the range of 844.27~1575.6 $cm^2$/g and 10.6~12.9 (equation omitted), respectively. From the adsorption studies on the antibacterial ACFs, typical Type I isotherms were obtained. And, from the SEM morphology results, it was observed that the surface of ACFs was partially coated by antibacterial materials after the treatment. Finally, from the antibacterial effects of antibacteral ACFs against E. coli, excellent antibacterial activity was shown. Concerning the above results, antibacterial ACFs can have wide application in the areas of sterilization, anti-fragrant. anti-insects.

• Journal of Korean Society of Environmental Engineers
• /
• v.29 no.8
• /
• pp.950-955
• /
• 2007

Non-point source control system which had been designed only for oil-water separation in the fields of oil refinery and garage was upgraded in this research for the removal of runoff pollutants in impervious urban area. Pollutants including oil from driveway and bridge were eliminated by two types of pathway in the system. One is the coalescence mechanism that the oil droplets in the runoff come into contact with each other in the spiral buoyant media surface and form larger coalesced droplets of oil that are carried upstream to the oil layer. The other is the precipitation that solids in runoff were settled by gravity in the system. In this research, coalescing characteristics of oil and water separation were investigated through image analyses, and efficiencies of the non-point source control system were evaluated using dust in driveway and waste engine oil. Media made of high density and high molecular weight polyethylene was indeterminate helical shape and had sleek surface by analysing SEM photographs and BET. Surface area and specific gravity of media which were measured directly were 1,428 $mm^2$ and 45.3 $kg/m^3$ respectively. From the image analyses of the oil droplets photographs which were taken by using microscope, it was proved clearly that the coalescence was the main pathway in the removal of oil from the runoff. Finally, the performances of the non-point source control system filled up with the media were suspended solid $86.6\sim95.2%$, $COD_{Cr}$, $87.3\sim95.4%$, n-Hexane extractable materials $71.8\sim94.8%$ respectively.

• Membrane Journal
• /
• v.14 no.4
• /
• pp.312-319
• /
• 2004

The porous SiO$_2$-B$_2$O$_3$ membrane was prepared from Si(OC$_2$$H_5$)$_4$-($CH_3$O)$_3$B-C$_2$$H_5$OH-$H_2O$ system by sol-gel method. In order to investigate the characteristics of this membrane, we examined that using BET, IR spectrophotometer, X-ray diffractometer, SEM and TEM. At $700^{\circ}C$, the surface area of SiO$_2$-B$_2$O$_3$ membrane was 354.398 $m^2$/, the median pore diameter was 0.0048 ${\mu}{\textrm}{m}$, and the particle size of SiO$_2$-B$_2$O$_3$ membrane was 7 nm. The separation properties of the gas mixture ($H_2$/$N_2$) through the SiO$_2$-B$_2$O$_3$ membrane was studied as a function of pressure. The real separation factor($\alpha$) of SiO$_2$-B$_2$O$_3$ membrane for $H_2$/$N_2$ gas mixture was 4.68 at 155.15 cmHg and $25^{\circ}C$. The real separation factor($\alpha$), head separation factor($\beta$) and tail separation factor((equation omitted)) were increased as the pressure of permeation cell increased.

• Analytical Science and Technology
• /
• v.23 no.6
• /
• pp.566-571
• /
• 2010

This paper describes the sorption behaviors of aqueous uranium ions on the K-birnessite. K-birnessite was synthesized by adding a concentrated HCl to an aqueous solution of $KMnO_4$. Physicochemical characteristics of the K-birnessite, such as structure, specific surface area and surface charge, were investigated. K-birnessite is a layered material and the $K^+$ ions exist in the interlayer of layered K-birnessite. BET specific surface area of the K-birnessite was 38.30 m2/g. The surface charge of K-birnessite was $-1.65\;C/m^2$ at pH 5.00 and ionic strength of 0.010 M $NaClO_4$, at which the sorption experiments of uranium ions were carried out. Uranium ions were incorporated into the interlayer of the K-birnessite by cation-exchange reaction with $K^+$ ions, and the distribution coefficient is quite similar to those of common ion-exchange materials. The results might be applicable in the retardation of migration of radioactive materials from the underground disposal site of high-level radioactive waste.

• Korean Chemical Engineering Research
• /
• v.43 no.1
• /
• pp.140-145
• /
• 2005

The desulfurization abilities using GC/microreactor have been examined for $CuO-Fe_2O_3$ sorbents with respect to calcination temperatures of 700, 900 and $1,100^{\circ}C$. CuO was used as a main active component, $Fe_2O_3$ was used as an additive one and 25 wt% $SiO_2$ was used as a support. The desulfurization reaction temperature was $500^{\circ}C$ and the regeneration reaction temperature was $700^{\circ}C$. From the XRD results, the $CuFeO_2$ compound has been observed for the fresh sorbent calcined at $1,100^{\circ}C$ and the $CuFeS_2$ compound for the reacted sorbent calcined at $1,100^{\circ}C$. By the BET results, however any significant differences among sorbents calcined at the three different temperatures of 700, 900 and $1,100^{\circ}C$ haven't been observed. Especially CFS1 (CuO : $Fe_2O_3$ : $SiO_2$=67.5 wt% : 7.5 wt% : 25 wt%) sorbent calcined at $1,100^{\circ}C$ maintained about 10 g sulfur/100 g sorbent for 100 cycles by the cyclic test.

• Clean Technology
• /
• v.18 no.1
• /
• pp.95-101
• /
• 2012

The Co and Ni catalysts supported on $Al_2O_3$ for partial oxidation of methane producing hydrogen were synthesized using impregnation to incipient wetness. And the promotion effects of metals such as Mg, Ce, La and Sr in partial oxidation of methane over these $Co/Al_2O_3$ and $Ni/Al_2O_3$ were investigated. Reaction activity of these catalysts for the partial oxidation of methane was investigated in the temperature range of 450~$650^{\circ}C$ at 1 atm and $CH_2/O_2$ = 2.0. The catalysts were characterized by BET, XRD and SEM/EDX. The results indicated that the catalytic performance of these catalysts was improved with the addition of 0.2 wt% metal promoter. The Mg promoted $Co/Al_2O_3$ catalyst showed the highest $CH_4$ conversion and hydrogen selectivity at higher temperature than $500^{\circ}C$. The Ce and Sr promoted Ni catalysts superior to Co-based catalysts in the low temperature range. The addition of metal promoter to $Co/Al_2O_3$ and $Ni/Al_2O_3$ catalysts increased the surface area.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.30 no.3 s.47
• /
• pp.321-328
• /
• 2004

Nano silica ball and nano carbon ball are developed commercially by template synthesis method. Adsorption of unpleasant smelling substances such as ammonia, trimethylamine, acetaldehyde and methyl mercaptane onto nano carbon ball with hollow macroporous core/mesoporous shell structures, nano carbon ball, was investigated and compared with that onto odor adsorbent materials, activated carbon, commercially available. The adsorption and decomposition of malodor at nano carbon ball exhibited superior than those onto activated carbon. The physicochemical properties such as mesopore size distributions, large nitrogen BET specific surface area and large pore volume and decomposition of malodor were studied to interpret the predominant adsorption performance. The nano carbon ball is expected to be useful in many applications such as deodorizers, adsorbent of pollutants.

• Applied Chemistry for Engineering
• /
• v.29 no.4
• /
• pp.461-467
• /
• 2018

In this study, $(n-BuCp)_2ZrCl_2$, was supported on $SiO_2/MgCl_2$ binary support. Before supporting the catalyst, the $SiO_2/MgCl_2$ binary support was surface treated with three different alkyl aluminum compound, namely trimethylaluminum, triethylaluminum, and ethylaluminum sesquichloride. The synthesized surface-treated $SiO_2/MgCl_2$ supported metallocene catalysts were used for the copolymerization of ethylene and 1-hexene. Their catalytic properties and performances were analyzed through BET, XPS analysis, ICP-AES analysis, and FE-SEM. While the resulting copolymers were analyzed through DSC analysis, GPC analysis, 13C-NMR analysis, and FE-SEM. The analysis of synthesized surface-treated $SiO_2/MgCl_2$ supported metallocene catalysts showed that the Zr content of these catalysts is relatively lower compared to that of the catalyst supported on $SiO_2$. This could be attributed to the reduction in the surface area of $SiO_2$ due to the presence of recrystallized $MgCl_2$ and alkyl aluminum. Furthermore, they exhibited a better copolymerization activity compared to that of $SiO_2$ supported catalyst, particularly the EASC-surface treated binary support, which has the highest activity of 1.9 kg PE/($mmol-Zr^*hr$) because EASC acts as a strong Lewis acid. It could also be observed that the larger the ligand of alkyl aluminum used, the rougher the particle surface of the resulting polymer.

• Journal of the Korean Applied Science and Technology
• /
• v.36 no.2
• /
• pp.668-675
• /
• 2019

Fine dust in air pollutants is recognized as one of the most serious social environmental problems. Most of the NOx is generated in a combustion process such as that of a coal-fired power plant, and therefore efficient elimination of the NOx from the coal-fired power plants is needed. This study investigates the removal efficiency of using $TiO_2$, a photocatalyst, to remove NOx by Selective Catalytic Reduction (SCR). To evaluate the NOx removal efficiency, $TiO_2$ catalyst and phosphate binder were mixed on the surface of the $Al_2O_3$ substrate with the exothermic agent, and the substrate was heat-treated. The NOx removal efficiency of the catalysts was evaluated according to the temperature, and XRD, SEM, TG-DTA and BET analyzes were performed to investigate the physicochemical properties of the catalysts. NOx removal efficiency was 58.7%~65.9% at 20min, 63.7~66.0% at 30min with temperature change according to time($250^{\circ}C{\sim}500^{\circ}C$). The $TiO_2$ used in the SCR for NOx removal is judged to have the most efficient removal efficiency at $300^{\circ}C$.

• Applied Chemistry for Engineering
• /
• v.22 no.2
• /
• pp.173-177
• /
• 2011

In this study, the formation of $AlPO_4$-type porous materials from alum sludge was investigated. The materials were synthesized by the reaction of aluminum hydroxide and phosphoric acid with an organic template. Cationic surfactant, natural humic acid, and amino acids were used for the organic template. The residual organic templates were removed by calcination at $600^{\circ}C$ in the air. Powder X-ray diffraction patterns showed the charicteristic patterns of the $AlPO_4$-type porous materials. The morphology of the material was examined using a scanning electron microscopy. The coordination environment of $Al^{3+}$ ion was investigated by $^{27}Al$ MAS NMR technique. Both tetrahedrally and octahedrally coordinated$Al^{3+}$ ions were found in the as-synthesized samples while all $Al^{3+}$ ions were tetrahedrally coordinated in the calcined products. The development of mesopore in the solid material was confirmed by the measurement of BET specific surface area. Finally, they were used for removal of toxic formaldehyde from the air and the formaldehyde molecules were adsorbed on the surface of pores. In conclusion, $AlPO_4$-type porous materials from alum sludge might be applicable in the removal of toxic volatile organic compounds from the air.