• Journal of Wetlands Research
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• v.20 no.3
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• pp.263-271
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• 2018

In this study, we analyzed the removal efficiency of ammonia nitrogen and phosphate dependant on the column depths using various absorbents such as zeolite silica sand, and activated carbon through the column test. In addition, we analyzed electrochemical adsorption behaviors of ammonia nitrogen and phosphate through the quantum mechanical calculation based on density functional theory calculation. Experimental results represent the removal efficiency of ammonia nitrogen and phosphate are zeolite > activated carbon > silica sand, and activated carbon > zeolite > silica sand, respectively. Zeolite shows high adsorption property for ammonia nitrogen over 90%, regardless of the column depth, while activated carbon exhibits high adsorption property for both ammonia nitrogen and phosphate as the column depth for filter media increases. Theoretical findings using DFT calculation for the adsorption behaviors of adsorbents (activated carbon and silica sand) and nutrients ($PO_4{^{3-}}$, $NH_4{^{+}}$) show that activated carbon represented narrower HOMO-LUMO band gap with high adsorption energy, and even more favorable environment for electron adsorption than silica sand, which leads to the effective removal of nutrients.

• Journal of Soil and Groundwater Environment
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• v.13 no.1
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• pp.101-109
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• 2008

The adsorption characteristics of cationic metals such as copper, cadmium, and lead onto the amorphous aluminum oxide, AMA-L, which was mineralized from raw sanding powder at $550^{\circ}C$ were investigated. Additionally, surface complexation reaction of cationic heavy metals onto AMA-L was simulated with MINEQL + software employing a diffuse layer model. From the batch adsorption tests in a single element system, the adsorption affinity of each metal ion onto AMA-L was following order: lead > copper > cadmium. In a binary system composed with copper and cadmium, quite a similar adsorption affinity was observed in each metal ion compared to the single element system. When the surface complexation constants obtained in the single system were used in the prediction of experimental adsorption results, model predictions were well fitted with experimental results of both single and binary systems.

• Journal of the Mineralogical Society of Korea
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• v.15 no.4
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• pp.315-327
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• 2002

Al-pillared clay was synthesized by constructing pillars of aluminum oxides at the interlayer of montmorillonite in bentonite. XRD, DTA and chemical analyses of Al-pillared clay were performed to examine mineralogical properties. Batch adsorption experiments were also conducted to determine the adsorption properties of this synthesized clay for phosphate ions. XRD analyses showed that the interlayer space of Al-pillared clay expanded to 18.03 $\AA$ at room temperature and shifted to $17 \AA$ after heating to $550^{\circ}C$. A small change in interlayer space after heating indicates high thermal stability. The interlayer expansion by glycerol was also very small. From DTA analyses, pillared clay showed the characteristic endothermic peaks at 270 and $420^{\circ}C$ , which might be caused by dehydration in framework of pillars between interlayers. Adsorption experiment revealed that Al-pillared clay had an excellent adsorption capacity to the phosphate ions, whereas montmorillonite had very low adsorption capacity to phosphate ions. In phosphate solution concentration up to 300 mg/L, 2 g of pillared clay could uptake almost 100% of phosphate ions from 20 mL of solution. After heat treatment of the phosphate adsorbed pillared clay at 50$0^{\circ}C$ to remove phosphate, the calcined pillared clay could adsorb phosphate ions with a little decreased adsorption efficiency. This fact indicates that Al-pillared clay can be recycled for the adsorption of phosphate ions.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.10
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• pp.1861-1867
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• 2000

Granular activated carbon(GAC) adsorption is one of the best available technology to remove synthetic organic chemicals(SOCs) from water supplies and wastewater. In order to satisfy enviromental criteria and reduce GAC treatment cost, optimal study of reverse stratified tapered adsorber(RSTA) has been conducted. The RSTA was found to provide on increase in breakthrough time when compared to a conventional cylindrical adsorber(CA). Through the RSTA optimal experiment, optimal mean bed velocity was decided 19.10cm/min and optimal angle was decided RSTA($3.0^{\circ}$). Adsorption efficiency was increased with increasing activated carbon doses and the number of activated carbon layers.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.113-113
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• 2016

반도체 산업이 발전하고 기술이 향상됨에 따라 미세화되고 복잡한 구조의 소자가 개발되고 있으며, 2차원 소재 등 다양하고 새로운 소재들이 발견 및 연구되고 있다. 새로운 소재 또는 기술을 이용한 고품질 소자를 개발하기 위해서는 우수한 특성(높은 순도, 우수한 분해 및 반응 특성)을 지닌 증착소재의 개발 및 평가가 선행되어야 한다. 기존의 증착소재의 기본 물성을 측정하는 방법인 단순 기상 Fourier transform infrared spectroscopy(FT-IR) 분석법은 실제 공정에서의 증착경향을 대변하기 어렵다는 단점이 있다. 이러한 단점을 보완하기 위해 개조된 attenuated total reflection (ATR) 액세서리를 이용하여 실제 공정에서의 증착경향을 대변하고자 하였다. 본 연구에서는 반도체 증착소재의 분해 및 표면 흡착 특성을 분석하기 위해 ATR-FTIR 분석법을 이용하여 수행하였으며, 분산안정도에 따른 nanoparticle을 ATR의 크리스탈 표면에 분포시켜 hexamethyldisilazane(HMDS) source의 흡착 효율을 향상시키는 연구를 수행하였다. Nanoparticle의 분산안정도를 높이기 위하여 suspension 상태에서 pH, sonication, 분산제를 이용하였으며, nanoparticle을 ATR crystal 표면에 분포하여 분석한 결과, 분산안정도에 따라 HMDS의 흡착효율이 달라짐을 확인하였다.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.158-161
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• 2003

To develop an effective adsorbent for radio active Carbon Dioxide, $^14CO_2$, which is discharged to nearby atmosphere from nuclear power plants of CANDU type, we made some preliminary adsorbents and tested their abilities of $CO_2$ removal. The chemical agents used was LiOH and we supported or impregnated it on the surface or the internal volume of activated Carbon(GW-H). The physical and chemical properties of various adsorbents were measured using methods such as XRD, BET. SEM images were taken to investigate the change of surface morphology of the adsorbents. Finally, amount of $CO_2$ adsorption of them were verified under specific conditions. We found that mechanical mixing of LiOH and activated Carbon showed the maximum $CO_2$ removal ability, while surface activation of activated Carbon by Nitric Acid-treatment enhanced its $CO_2$ removal efficiency to some degree.

• Applied Biological Chemistry
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• v.38 no.5
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• pp.452-454
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• 1995

Chitin and chitosan from red crab and squid pen were applied as adsorbents for trapping the dyes in wastewater from dyeworks. We found that the chitin and chitosan were effective adsorbents for the dyes discarded from dyeworks. Chitosan was more effective in dye adsorption than chitin. In a continuous elution column experiment, 1 kg of chitosan could be used for treatment of upto 120 L of wastewater containing 0.05% dye wasted from dyeworks at 75% efficacy, that means 45g dye was adsorbed per kg chitosan.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1994.11a
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• pp.90-96
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• 1994

본 연구는 에너지를 집중적으로 사용하는 발전소와 대규모 공장 단지에서 발생하는 배기가스 중에 포함된 황산화물의 제거 방법에 관한 것으로서, 활성탄의 적절한 전처리를 통해 이산화황 흡착능을 향상시켜 머지 않은 장래에 엄격히 적용될 대기오염 기준을 만족시킴과 동시에, 오염 물질의 제거 효율이 높고 폐기물 매립의 부담이 없는 건식 탈황 공정의 효율향상에 기여하는 것을 목적으로 하고 있다. Activated Char나 활성탄을 이용하여 황산화물과 질소산화물을 동시에 제거하기 위해서는 Carbon 표면을 적절하게 처리함으로써 활성탄의 촉매활성을 향상시키는 것이 필요하다. 따라서 본 연구에서는 활성탄을 열 및 $O_2$-NH$_3$ 혼합가스로 전처리하여 표면의 특성 변화와 SO$_2$ 흡착능에 미치는 영향을 살펴보았다. Coconut Shell로부터 제조한 활성탄을 NH$_3$의 농도를 변화시켜가며 $O_2$와의 혼합가스로 973~1173K에서 열처리하는 방법에 의해 전처리하여, 이률 고정층 반응기에서 SO$_2$흡착 및 반응실험을 수행하였고, 이 과정 중의 활성탄 표면의 특성변화를 원소분석, TPD(Temperature Programmed Desorption), FTIR(Fourier Transform Infrared Spectroscopy), Acid-Base Titration, SEM(Scanning Electrolic Microscopy)등의 분석 방법을 통해서 알아보았다. 그 결과, 활성탄을 열 및 $O_2$-NH$_3$혼합가스로 처리하여 환원성 분위기 하에서 표면 활성점을 증가시킴으로써 황산화물 흡착제거율이 향상됨을 얻었다.

• Journal of Wetlands Research
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• v.20 no.4
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• pp.410-416
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• 2018

This experiment was carried out with the purpose of testing nickel and copper adsorption abilities of multi wall carbon nanotube (MWCNT) and activated carbon. In the acidic condition, only MWCNT was effective for removing nickel and copper ion in the aqueous phase while activated carbon rarely remove them. The MWCNT and heavy metals adsorption reaction followed pseudo-first order kinetic. When the initial pH value was neutral (pH=7), nickel was rapidly removed by MWCNT and activated carbon in 4 hr (99.02 %, 80.30 %). Also, copper ion was rapidly removed by both adsorbents in 4 hr when the initial pH was 7 (100 %, 99.73 %). Increasing of adsorbent dosages affect the pH evolution and heavy metal ions removal (0 ~ 99%). Also, oxidation pretreatment enhanced the adsorption efficiency of MWCNT.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2001.11a
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• pp.21-21
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• 2001

자원재활용과 원가절감를 위해 고지재활용율이 크게 상승하고 있으며, 이와 아울러 고 지원료로부터 고품질의 제품을 생산할 수 있는 기술에 대한 관심이 증대되고 있는 실 정이다. 저급 고지로부터 고품질의 탈묵펄프를 얻기 위해서는 고지재활용공정의 핵심 공정인 부유부상 공정의 효율화가 가장 중요하다고 믿어진다. 이를 위해서는 부유부상 공정에 가장 큰 영향을 미치는 고형입자의 표면 화학적 특성에 따른 공정의 분리효율 평가와 이에 근거한 공정해석과 개선이 요청된다. 이러한 부유부상 공정을 표면화학적 측면에서 구명하기 위해 마이크로 크리스탈린 셀룰로오스(Microcrystalline cellulose: M MCC)를 모댈 물질로 사용하여 표면화학적 특성은 다르나 입자의 크기와 형태는 동일 한 시료를 준비하였다. 친수성의 표면 특성을 나타내는 MCC의 표면 특성을 바꾸기 위 하여 AKD(alkyl ketene dimer)로 처리비율을 달리하여 솔벤트 사이징 처리를 실시하 였다. 이렇게 준비된 MCC의 표면화학적 특성을 IGC를 이용하여 평가하였다 .. IGC는 G GC를 응용한 표면분석 기술로 고체의 물리화학적 특성과 흡착성을 분석하기 위해서 사용되며 이로부터 흡착제의 표면특성을 평가할 수 있다. 본 실험에서는 AKD로 소수화 정도가 다르도록 소수화시킨 MCC 시료를 이용하여 I IGC 칼럼을 준비하고 n-알칸과 몇가지 극성 용매률 이용하여 이들의 칼럼 내 체류시 간을 측정함으로써 흡착특성을 평가하고 이로부터 흡착현상을 열역학적으로 분석하였다. IGC 분석 시에는 칼럼의 온도를 $30^{\circ}C$, $35^{\circ}C$, $40^{\circ}C$의 3수준으로 변화시켰다. 측정결 과로부터 MCC 표면의 흡착자유에너지와 엔탈피, 엔트로피의 변화량을 평가하였으며, 또한 MCC 표면의 극성에너지와 산염기적 성질을 평가하였다. 실험결과 MCC의 소수화도에 따른 열역학적 흡착현상의 차이가 명백하였다. 이는 소 수화 수준에 따라 소수성 및 친수성 물질의 흡착성이 변화된다는 것을 보여준다. 따라서 탈묵 시 진행되는 기포에의 부착현상을 평가할 수 있는 기초자료로 활용될 수 있다 고 사료되었다.