• 한국수산과학회지
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• 제32권4호
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• pp.399-403
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• 1999

우리나라 인근 해역에서 가장 쉽게 채취할 수 있는 해조류 중의 하나인 S. sagamianum을 이용한 Pb 및 Cr의 생체흡착 실험을 수행하였다. Pb 및 Cr은 15분 안에 흡착 평형에 도달하였으며, 평형흡착량은 각각 224.5mg Pb/g biomass 및 77.5mg Cr/g bio-mass로서 Pb의 흡착량이 Cr보다 약 3배정도 높았다. 또한 pH가 감소할수록 Pb 및 Cr의 홉착량은 감소하였으나 Pb가 상대적으로 많은 영향을 받는 것으로 나타났다. Pb, Cr, Cu 및 Cd 혼합용액에서는 Pb>Cu>Cr>Cd 순으로 흡착하였으며, Pb 및 Cr 이온이동량 존재하는 용액에서의 흡착은 거의 1 : 1로 흡착이 이루어졌다. Pb 및 Cr흡착 후에 0.1 M HCl, 0.1 M $HNO_3$ 및 0.1 M EDTA으로 탈착 실험을 수행하니, Pb는 의 경우에는 $95\%$이상 탈착되었으나 Cr의 경우 S. sagamianum와의 결합력이 상대적으로 강하여 탈착율이 $51\%$이하로 낮았다.

• Carbon letters
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• 제20권
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• pp.10-18
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• 2016

Nanoporous carbon structures were synthesized by pyrolysis of grass as carbon precursor. The synthesized carbon has high surface area and pore volume. The carbon products were acid functionalized and characterized by Fourier transform infrared spectroscopy, X-ray diffraction, Brunauer–Emmett–Teller, transmission electron microscopy, and Energy Dispersive X-ray microanalysis. Acid functionalized nanoporous carbon was explored for use in removal of toxic Cr(VI) ions from aqueous media. An adsorption study was done as a function of initial concentration, pH, contact time, temperature, and interfering ions. The experimental equilibrium data fits well to Langmuir isotherm model with maximum monolayer adsorption capacity of 35.335 mg/g. The results indicated that removal obeys a pseudo-second-order kinetic model, and that equilibrium was reached in 10 min. A desorption study was done using NaOH. The results of the present study imply that acid functionalized nanoporous carbon synthesized from grass is an efficient, renewable, cost-effective adsorbent material for removal of hexavalent chromium due to its faster removal rate and reusability.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.332-332
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• 2011

The adsorption and desoprtion properties on Pt(111) of chiral molecules, propylene oxide (PO) and 1,3-dimethyl butylamine (DMBA), have be characterized in utrahigh vacuum. Precision-doses of PO and DMBA onto a Pt(111) surface at 90 K have been achieved with a directed tubular molecular doser controlled by a micron-sized orifice and the reservoir gas pressure. Temperature-programmed desorption (TPD) mass spectra have been employed together with low-energy electron diffraction (LEED) analyses. In addition to the separate adsorption behaviors of PO and DMBA, the enantioselective adsorption of R- and S-PO on Pt(111) precovered with R- or S-DMBA have been investigated thoroughly, and the results will be presented.

• 한국환경보건학회지
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• 제27권2호
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• pp.138-144
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• 2001

This study was carried out to investigate characteristics and Pb(II) removal effect of natural clays in the batch mode test. The effect of parameters such as temperature, adsorption time and coexisting cations on the sorption ability and characteristics was investigated to find out whether the clays could be used as adsorbents. Several natural clays from domestic have been investigated to have high specific surface area and have minerals such as SiO$_2$ and $Al_2$O$_3$. As a result, removal effects of Pb(II) on clays were reached at equilibrium in aqueous solutions by stirring about 20 minutes. The removal effect of Pb(II) was best for Kang Jin clay than other clays in terms of fixed time. Adsorption efficiency was not influenced by the possibility of continuous treatment system of wastewater which contain heavy metals by using natural clays from domestic.

• Nuclear Engineering and Technology
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• 제54권6호
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• pp.1991-2003
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• 2022

The problem of water contamination by long-living cesium and strontium radionuclides is an urgent environmental issue. The development of facile and efficient technologies based on nanostructured adsorbents is a perspective for selective radionuclides removal. In this regard, current work aimed to obtain the nanostructured magnetic zeolite composites with high adsorption performance to cesium and strontium ions. The optimal conditions of hydrothermal synthesis were established based on XRD, SEM-EDX, N₂ adsorption-desorption, VSM, and batch adsorption experiment data. The role of chemical composition, textural characteristics, and surface morphology was demonstrated. The monolayer ionexchange mechanism was proposed based on adsorption isotherm modeling. The highest Langmuir adsorption capacity of 229.6 and 105.1 mg/g towards cesium and strontium ions was reached for composite obtained at 90 ℃ hydrothermal treatment. It was shown that magnetic characteristics of zeolite composites allowing to separate spent adsorbents by a magnet from aqueous solutions.

• Carbon letters
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• 제9권1호
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• pp.23-27
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• 2008

The adsorption and reduction of Cr (VI) to Cr (III) by surface modified activated carbon (AC) in an aqueous solution was studied. The effects of surface modifications on the properties of the carbons were investigated by the analysis of specific surface area, carbon surface pH, acid/base surface values and functional groups. In order to understand the Cr(VI) adsorption and reduction ratio from Cr(VI) to Cr(III), the Cr adsorption capacity of AC was also measured and discussed by using inductively coupled plasma and UV spectrophotometer. The modifications bring about substantial variation in the chemical properties whereas the physical properties such as specific surface area, pore volume and pore size distribution nearly were not changed. Total Cr adsorption efficiency of as-received activated carbon (R-AC) and nitric acid treated activated carbon (N1-AC and N2-AC) were recorded on 98.2, 99.7 and 100%. Cr(III) reduction efficiency of R-AC increased largely from 0.4% to 28.3% compared to N1-AC and N2-AC.

• Korea-Australia Rheology Journal
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• 제15권4호
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• pp.179-185
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• 2003

Associating polymers act as flocculants in colloidal suspensions, because the hydrophobic groups (hydrophobes) can adsorb onto particle surfaces and create intermolecular cross-linking. The steady-shear viscosity and dynamic viscoelasticity were measured for suspensions flocculated by multichain bridging of associating polymers. The effects of surfactant on the suspension rheology are studied in relation to the bridging conformation. The surfactant molecule behaves as a displacer and the polymer chains are forced to desorb from the particle surfaces. The overall effect of surfactant is the reduction of suspension viscosity. However, the additions of a small amount of surfactant to suspensions, in which the degree of bridging is low, cause a viscosity increase, although the number of chains forming one bridge is decreased by the forced desorption of associating polymer. Since the polymer chains desorbed from one bridge can form another bridge between bare particles, the bridging density over the system is increased. Therefore, the surfactant adsorption leads to a viscosity increase. The surfactant influences the viscosity in two opposing ways depending on the degree of bridging.

• 한국진공학회지
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• 제14권2호
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• pp.69-77
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• 2005

중성입자빔 가열장치의 이온원과 빔라인 부품들을 개발하고 시험하기 위해 제작한 부피 $60m^3$의 시험설비에는 특성 비교를 위해 몇 가지 다른 방식으로 제작된 대용량 크라이오 흡착펌프를 장착하여 사용하고 있다. 크라이오 펌프의 활성탄 패널을 냉각시키면서 수소를 적절한 간격으로 도입하여 수소 분압을 측정하고 그 시간적인 변화를 통해 온도에 따른 수소흡착과 방출특성을 분석해 보았으며 관련 파라미터 사이의 상호 영향에 대해 알아보기 위해 시뮬레이션을 수행했다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.642-645
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• 2007

석탄, 폐기물 등 다양한 시료의 가스화 반응을 통해서 발생되는 합성가스는 CO, $H_2$, $CO_2$가 주성분으로 가스엔진, 가스터빈 등의 연료로 사용하여 발전하거나 합성반응을 통해 다양한 화학원료로의 전환이 가능하다. 합성가스를 가스엔진, 가스터빈, 연료전지등의 연료로 사용하는 경우는 고효율 발전이 가능하여 기존 연소방식의 발전과 비교하여 단위 전력 생산량 당 $CO_2$의 배출량이 감소 되며, 여기에 $CO_2$ 분리공정을 적용하면 $CO_2$ 배출량 감소효과를 극대화 할 수 있다. 화석연료의 연소 및 가스화 반응을 통해서 발생하는 이산화탄소의 분리에 대한 많은 연구가 진행되고 있으나, 본 연구에서는 흡착방식을 이용한 합성가스 내의 이산화탄소 분리를 위하여 흡착제를 이용한 이산화탄소의 흡착, 탈착 성능 분석 연구를 수행하였다. 합성가스내의 이산화탄소를 분리하기 위한 흡착제로는 NaX 계열의 zeolite를 이용하였으며, 가스화 반응을 통해 발생한 합성가스를 흡착제에 통과시켜 이산화탄소의 선택적 흡착 여부를 확인하였다. 또한 TPD(Temperature Programmed Desorption)방법을 이용하여 흡착제의 이산화탄소 흡착 성능을 분석하였다.

• 대한환경공학회지
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• 제31권8호
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• pp.663-672
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• 2009

본 연구는 조류 Chlorella pyrenoidosa에 의한 Pb 흡착시 고정화 방법이 흡착특성에 미치는 영향에 관한 것으로, 고정화는 Ca-alginate, K-carrageenan, and polyacrylamide를 이용하여 실시하였다. 연구결과, 고정화에 따라 흡착평형 도달시간의 지연이 나타났으며, Pb의 최대 흡착능(mg/g)은 중금속 농도와 pH가 높을수록, 고정체 투입량이 적을수록 높게 나타났다. 고정화 방법별 흡착능은 Ca-alginate로 고정화한 경우 가장 높은 흡착능을 나타낸 반면, 흡착량이 pH에 가장 민감하게 영향을 받았다. Pb 흡착현상은 Freundlich 등온흡착식에 의해 잘 해석되었고, 흡착속도는 2차 모형식을 따르는 것으로 나타났다. FT-IR분석으로 Chlorella pyrenoidosa에 의한 Pb의 생물흡착 메커니즘이 주로 carbo-acid와 amide 그룹에 Pb가 결합되어 일어남을 알 수 있었다. 흡착된 Pb의 탈착은 탈착제 농도가 높을수록 탈착 효율도 높았다. 실험에 사용되어진 여러 탈착제(NTA, HCl, EDTA, $H_2SO_4,\;Na_2CO_3$)중 Ca-alginate과 K-carrageenan로 고정화한 경우 NTA가 가장 높게 나타났으며, polyacrylamide로 고정한 경우 EDTA를 사용한 경우 가장 효과적인 것으로 나타났다. 고정화 방법별 최대 탈착효율은 각각 90.0, 83.0, 80.0% 이었다.