• 환경위생공학
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• 제23권1호
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• pp.57-65
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• 2008

Resins were synthesized with 1-aza-15-crown-5 macrocyclic ligand attached to styrene(dangerous matter) divinylbenzene(DVB) copolymer with crosslink of 1, 2, 6 and 15% by substitution reaction. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time and crosslink on adsorption of metal ion　from water fire extinguishing agent by the synthetic resin adsorbent were investigated. The metal ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in water was in increasing order of $Mg^{2+}>Al^{3+}>Pb^{2+}$. The adsorption was in the order of 1, 2, 6, and 15% crosslink resin.

• 대한기계학회논문집B
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• 제31권2호
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• pp.116-124
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• 2007

An adsorption chiller is expected to have high energy-efficiency in utilizing the waste heat exhausted from a process. The objective of this paper is to investigate the performance of silica gel-water adsorption chiller from the cycle simulation and to provide a guideline for design of the adsorption chiller. The effect of cycle time, inlet temperature and water flow rate on the cooling capacity and COP is quantified during the cycle operation. It is found that the performance of adsorption chiller is more sensitive to the change of inlet water temperature rather than the water flow rate. It is concluded that the COP is 0.57 in the standard conditions(hot water $80^{\circ}C$, cooling water $30^{\circ}C$, chilled water inlet temperatures $14^{\circ}C$ and cycle time 420sec).

• 환경위생공학
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• 제22권3호
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• pp.77-87
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• 2007

The ion exchange resins have been synthesized from chlormethyl styrene - 1,4 - divinylbenzene(DVB) with 1%, 3%, and 5%-crosslinking and macro cyclic ligand of OenNen-$H_4$ by copolymerization method and the adsorption characteristics of uranium(VI), iron(II) and samarium(III) metallic ions have been investigated in various experimental conditions. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time, dielectric constant of solvent and crosslink on adsorption of metallic ions were investigated. The uranium ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium ${UO_2}^{2+}>Fe^{2+}>Sm^{3+}$ ion. The adsorption was in order of 1%, 3%, and 5% crosslink resin and adsorption of resin decreased in proportion to order of dielectric constant of solvent.

• 환경위생공학
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• 제20권3호
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• pp.27-35
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• 2005

The ion exchange resins have been synthesized from chlormethyl styrene - 1,4 -divinyl-benzene(DVB) with $1\%,\;4\%,\;and\;10\%$-crosslinking and macrocyclic ligand of cryptand type by copolymerization method and the adsorption characteristics of uranium(VI), calcium(II) and lutetium(III) metallic ions have been investigated in various experimental conditions. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time, dielectric constant of solvent and crosslink on adsorption of metallic ions were investigated. The uranium ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium $(UO_2^{2+})>calcium(Ca^{2+})>lutetium(Lu^{3+})$ ion. The adsorption was order of $1\%,\;4\%,\;and\;10\%$ crosslink resin and adsorption of resin decreased in proportion to order of dielectric constant of solvents.

• 환경위생공학
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• 제21권3호
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• pp.52-60
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• 2006

The ion exchange resins have been synthesized from chlormethyl styrene-1,4-divinylbenzene(DVB) with 1%, 2%, and 20%-crosslinking and macrocyclic ligand of cryptand 21 by copolymerization method and the adsorption characteristics of uranium(VI), copper(II) and dysprosium(III) metallic ions have been investigated in various experimental conditions. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, equilibrium time, dielectric constant of solvent and crosslink on adsorption of metallic ions were investigated. The metal ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium$(UO^{2+}_2)\;>\;copper(Cu^{2+})\;>\;dysprosium(Dy^{3+})$ ion. The adsorption was in order of 1%, 2%, and 20% crosslink resin and adsorption of resin decreased in proportion to order of dielectric constant of solvents.

• Carbon letters
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• 제8권3호
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• pp.199-206
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• 2007

The activated carbon produced from rubber wood sawdust by chemical activation using phosphoric acid have been utilized as an adsorbent for the removal of Cu(II) from aqueous solution in the concentration range 5-40 mg/l. Adsorption experiments were carried out in a batch process and various experimental parameters such as effect of contact time, initial copper ion concentration, carbon dosage, and pH on percentage removal have been studied. Adsorption results obtained for activated carbon from rubber wood sawdust were compared with the results of commercial activated carbon (CAC). The adsorption on activated carbon samples increased with contact time and attained maximum value at 3 h for CAC and 4 h for PAC. The adsorption results show that the copper uptake increased with increasing pH, the optimum efficiency being attained at pH 6. The precipitation of copper hydroxide occurred when pH of the adsorbate solution was greater than 6. The equilibrium data were fitted using Langmuir and Freundlich adsorption isotherm equation. The kinetics of sorption of the copper ion has been analyzed by two kinetic models, namely, the pseudo first order and pseudo second order kinetic model. The adsorption constants and rate constants for the models have been determined. The process follows pseudo second order kinetics and the results indicated that the Langmuir model gave a better fit to the experimental data than the Freundlich model. It was concluded that activated carbon produced using phosphoric acid has higher adsorption capacity when compared to CAC.

• 한국수처리학회지
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• 제26권6호
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• pp.143-152
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• 2018

The process parameters of ethyl violet from aqueous solution by activated carbon adsorption were carried out as a function of pH, temperature, contact time, initial concentration and temperature. The adsorption equilibrium data can be described well by the Langmuir and Freundlich isotherm models. Base on Langmuir constant ($R_L=0.0343{\sim}0.0523$) and Freundlich constant (1/n=0.1633~0.1974), This process could be employed as effective treatment for adsorption of ethyl violet. The kinetic experimental results showed that the adsorption process can be well described with the pseudo second order model. Based on the positive enthalpy (6.505 kJ/mol), the adsorption of ethyl violet onto granular activated carbon is endothermic. The negative Gibbs free energy (-1.169~-1.681 kJ/mol) obtained indicates that the adsorption process is spontaneous and physisorption.

• 대한환경공학회지
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• 제22권7호
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• pp.1213-1223
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• 2000

CDQ 분진을 흡착제로 사용하여 페놀의 흡착제거 양상을 검토하였다. CDQ 분진의 흡착능은 300 ppm의 페놀 용액에 대해 흡착평형시간 60분에서 약 42%의 흡착율을 보이는 것으로 나타났다. 페놀의 초기농도를 달리하여 흡착실험한 결과, 실험조건범위에서 농도가 증가함에 따라 흡착제거율이 증가하였으며 흡착양상은 Freundlich 등온흡착식에 잘 적용되었다. 흡착의 속도론적 해석시, 시간에 따른 속도식의 차수는 1차, 1.5차, 그리고 2차로 변화하는 것으로 파악되었다. 온도에 따른 흡착에서는 온도가 상승함에 따라 흡착제거량이 증가하여 흡열임을 보였으며, 이의 결과를 바탕으로 흡착에 대한 열역학적 데이터를 도출하였다. pH변화에 따른 페놀의 흡착량은 거의 변화가 없는 것으로 관찰되었으나, pH 11 이상의 영역에서는 다소 감소하는 것으로 나타났다.

• 한국환경보건학회지
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• 제34권3호
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• pp.240-246
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• 2008

The purpose of this study was to gain basic information on the characteristics of $CO_2$ adsorption in relation to $Na_2CO_3$, $K_2CO_3$, $Li_2CO_3$-impregnated activated carbon in a Fixed Bed Reactor. From the results of this study the following conclusions were made: $Na_2CO_3$, $K_2CO_3$, $Li_2CO_3$-impregnated activated carbon had a longer breakthrough time and more enhanced adsorption capacity than activated carbon alone. When tested with isothermal adsorption and tested for $CO_2$ adsorption the amount of $CO_2$ adsorbed varied with temperature, $CO_2$ inlet concentration, gas flow rate, aspect ratio, etc. Based on the results, when Langmuir, Freundlich and Dubinin-Polanyi adsorption isotherms were used for linear regression of isothermal adsorption data, Langmuir adsorption isotherm was the most suitable. And, the optimum condition for $Na_2CO_3$ and $K_2CO_3$ impregnated activated carbon make-up was 1N and $Li_2CO_3$ was 0.1N. It could be concluded that adsorption capacity was decreased with adsorption temperature and increased gas concentration. When the aspect ratio (L/D) was varied 0.5, 1.0 and 2.0, the significant drop of adsorption amount was observed below 1.0 and breakthrough time was shortened with gas flow rate.

• 자원리싸이클링
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• 제12권3호
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• pp.13-24
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• 2003

폐호도껍질을 원료로 활성탄을 제조하는 과정에서 활성화 온도, 활성화 시간, 활성화제의 양, 그리고 활성화제의 종류 등을 변수로 하여 활성화 특성을 조사하였다. 인산을 활성화제로 사용하여 제조된 활성탄은 그 흡착능이 온도가 증가함에 따라 증가하여 약 $550^{\circ}C$부근에서 최대 흡착능을 보였으며 그 수율은 온도 상승에 따라 지속적으로 감소하였다. 활성화 시간은 약 2시간 정도에서 최적의 조건을 보였으며 시간이 증가함에 따라 활성탄의 수율은 계속 감소하였다. 활성화제의 농도 증가에 따라 수율은 지속적으로 상승하였으며 흡착능 또한 증대되다가 약 1.5M $H_3PO_4$ 이상의 조건에서는 오히려 흡착능이 감소하였다. SEM으로 관찰한 조건에 따른 활성탄의 미세구조의 변화는 조건별 흡착능의 변화와 잘 일치되었으며 활성화제의 종류는 활성화 과정에서 중요한 영향을 미치는 것으로 조사되었다. 제조된 활성탄의 흡착특성을 파악하기 위해 $Cu^{2+}$ 이온을 흡착질로 하여 흡착반응을 조사한 결과, 흡착반응은 전체적으로 2차식을 따르는 것으로 관찰되었으며 흡착질의 초기 농도가 감소함에 따라 반응상수는 점차 증가하였다. 평형흡착량은 Freundlich Model 을 잘 따르는 것으로 나타났으며 온도별 흡착반응을 검토한 결과, 중금속 이온의 흡착은 흡열반응의 특성을 나타내었다. 흡착에 따른 Activation Energy는 약 13.07kcal/mol로 산출되었으며 van't Hoff Equation을 이용하여 흡착반응의 열역학적 인자들을 계산하였다.