• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1309-1314
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• 2011

People spend approximately 80 ~ 90 % of their time in various kinds of indoor spaces. And, in metropolitan area, most people spend more than 1 hour in public transportation everyday. For this reason, people's interest in the indoor air quality is drastically increasing. Among various indoor air pollutants, $CO_2$ is one of the most severe environmental concerns. Ventilation is commonly used to keep low $CO_2$ concentration in the passenger cabin. However, ventilation may worse the indoor air quality problem in case of subway because the tunnel is seriously polluted by particulate matters. In this study, an alternative way to remove $CO_2$ was suggested. The adsorption of $CO_2$ by $CO_2$ adsorbent was studied. Zeolite modified with base was prepared, and $CO_2$ removal performance was tested in $4m^3$ and $24m^3$ environmental chambers. It was found that $CO_2$ adsorbent could effectively remove $CO_2$ in the chambers.

• Bulletin of the Korean Chemical Society
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• v.29 no.6
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• pp.1115-1120
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• 2008

The adsorption of CO on W(110) surfaces was studied using thermal desorption spectroscopy (TDS), and core and valence level spectroscopy. At 120 K, CO forms a tilted structure at lower coverages ($\alpha$ 1), whereas it adsorbs normal to the surface at higher coverages ($\alpha$ 2). Tilted structures have been suggested to be precursors of dissociative chemisorption; however, experimental evidence is provided for the non-dissociative chemisorption of CO at temperatures above 900 K (which is referred to as the $\beta$ -state): TDS shows first order desorption kinetics. The core and valence level spectra of O/W(110) and those of $\beta$ -CO/W(110) are different. Most importantly, the 4$\sigma$ molecular orbital of CO can be identified in the valence level spectra of the $\beta$ -CO.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.172.1-172.1
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• 2011

본 연구에서는 매립지에서 발생하는 주요한 가스인 $CO_2$(47~55%)와 $CH_4$(47~55%)가스를 분리하기 위하여 여러 $CO_2$ capture 방법 중 Zeolite를 사용한 흡착법을 이용하였다. 국내에서 시판되고 있는 powder형 Zeolite 13X에 Inorganic binder와 organic binder를 최적의 비율로 혼합한 후 증류수를 이용하여 Pellet type 흡착제를 제조하였다. 또한 최종적으로 $CO_2$의 흡착능을 높이기 위하여 양이온(1M의 KCl, NaCl, $CaCl_2$, $LiCl_2$)으로 이온교환을 하였다. 매립지 모사가스($CO_2$:40%, $CH_4$:60%)를 이용하여 실시간 분석기(Delta1600S)를 이용 두 가스의 분리와 $CO_2$ 흡착성능(mg-CO2/g-흡착제)을 확인하였다. 개발된 흡착제(AjouEpl 13X)는 ICP, XRD, XRF, BET 분석으로 제올라이트의 구조와 성분을 분석하였다.

• Proceedings of the Korean Nuclear Society Conference
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• 2002.05a
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• pp.283.2-283
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• 2002

• Journal of Korean Society of Water and Wastewater
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• v.30 no.4
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• pp.409-415
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• 2016

Magnetite particles were synthesized by co-precipitation of water-soluble 밀 스케일-derived precursor by various concentrations of (0.5, 0.67, 1, 2 N) NaOH and (0.6, 0.8, 1.2, 2.4 N) $NH_4OH$. It is theoretically known that as the concentration of the alkaline additive used in iron oxide synthesis increases, the particle size distribution of that iron oxide decreases. This trend was observed in both kind of alkaline additive used, NaOH and $NH_4OH$. In addition, the magnetite synthesized in NaOH showed a relatively smaller particle size distribution than magnetite synthesized in $NH_4OH$. Crystalline phase of the synthesized magnetite were determined by X-ray diffraction spectroscopy(XRD). The particles were then used as an adsorbent for phosphate(P) removal. Phosphorus adsorption was found to be more efficient in NaOH-based synthesized magnetite than the $NH_4OH$-based magnetite.

• Journal of Environmental Science International
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• v.20 no.5
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• pp.667-672
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• 2011

The purpose of this work is to present the experiment results by a dynamic adsorption of water vapor on pelletized zeolites (ADZ300, ADZ400, and ADZ500) in fixed bed. The breakthrough curves of water vapor with several different concentrations and temperature in the range of 25~45 $^{\circ}C$ on zeolite bed were investigated. In the same conditions, the breakthrough time on ADZ400 and ADZ500 were little longer than ADZ300, and the equilibrium adsorption capacity on ADZ500 was highest. The higher the concentration of water vapor was, the faster the breakthrough time was, and the slope of breakthrough curves showed a tendency to increase. The faster the flow rate of water vapor was, the faster the breakthrough time was relatively, but variations between flow rate and breakthrough time did not have a proportional relationship. The breakthrough curve maintained constant gradient in spite of variation of flow rate in the same concentration. The temperature rise in zeolite bed by adsorption heat was occurred in the early stage of adsorption. After water molecule layers were formed on the surface of zeolite, the temperature was slowly cooled by water vapors continuously flowed in as constant temperature. The greater the concentration of water vapor and adsorption temperature were, the temperature difference in zeolite bed was increased.

• Journal of the Korean Applied Science and Technology
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• v.37 no.5
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• pp.1222-1228
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• 2020

The adsorption and ion exchange properties of tin phosphate were studied in an aqueous solution of KCl, varing the pH and metal ion concentration in the solution. The data were explained on the basis of chemical equilibrium. Tin phosphate behaved as an acidic ion exchanger and had an adsorption selectivity toward the bivalent transition metal ions in the following order : Cu⁺² > Co⁺² > Ni⁺². As in the case of a weekly acidic exchanger, the change in hydration of metal ions played the dominant role in determining the selectivity of tin phosphate. In all cases the extent of adsorption increased with an increase in temperature and concentration. The apperance of irregular kinks in the titration curves justified the presence of several exchangeable adsorption sites with different pKa values.

• Economic and Environmental Geology
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• v.39 no.2 s.177
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• pp.103-109
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• 2006

Batch adsorption experiments were performed to adsorb cadmium [Cd(II)], copper [Cu(II)], and lead [Pb(II)] onto sphagnum peat moss. According to the results, 10-50 mg/L of Cd(II), Cu(II), and Pb(II) were effectively adsorbed and removed within 1 h by 1.0 g/L of sphagnum peat moss. The amounts of Cd(II), Cu(II), and Pb(II) adsorbed on sphagnum peat moss increased with increasing the initial concentrations. The kinetics for the adsorption of Cd(II), Cu(II), and Pb(II) on sphagnum peat moss was described well using the pseudo-second order model at different initial concentrations. The maximum adsorption capacities calculated from the Langmuir isotherm for Cd(II), Cu(II), and Pb(III) were 33.90, 29.15, and 91.74 mg/g, respectively. Experimental results showed that sphagnum peat moss was a very effective adsorbent on the adsorption of Cd(II), Cu(II), and Pb(II).

• Analytical Science and Technology
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• v.9 no.4
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• pp.406-410
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• 1996

The adsorption behaviors of transition metal ions on the poly(N,N'-bispalmitoyl-1, 12-diaza-3, 4;9,10-dibenzo-5,8-cyclopentadecane) has been determined by adsorption process in aqueous solution. The order of concentration factor(CF) and the amount of adsorption were Cu(II)

• Journal of Korean Society of Water and Wastewater
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• v.33 no.2
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• pp.131-140
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• 2019

This study used a packed column reactor and a horizontal flow mesh reactor to examine the removal of copper ions from aqueous solutions using pine bark, a natural adsorbent prepared from Korean red pine (Pinus densiflora). Both equilibrium and nonequilibrium adsorption experiments were conducted on copper ion concentrations of 10mg/L, and the removals of copper ions at equilibrium were close to 95%. Adsorption of copper ions could be well described by both the Langmuir and Freundlich adsorption isotherms. The bark was treated with nitric acid to enhance efficiency of copper removal, and sorption capacity was improved by about 48% at equilibrium; mechanisms such as ion exchange and chelation may have been involved in the sorption process. A pseudo second-order kinetic model described the kinetic behavior of the copper ion adsorption onto the bark. Regeneration with nitric acid resulted in extended use of spent bark in the packed column. The horizontal flow mesh reactor allowed approximately 80% removal efficiency, demonstrating its operational flexibility and the potential for its practical use as a bark filter reactor.