• 제목/요약/키워드: Adsorption Time

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실로퓨트에 대한 2-피콜린의 흡착 특성 평가 (Evaluation of Adsorption Characteristics of 2-Picoline onto Sylopute)

  • 양지원;김진현
    • Korean Chemical Engineering Research
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    • 제57권2호
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    • pp.210-218
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    • 2019
  • 실로퓨트를 이용한 식물세포 Taxus chinensis 유래 주요 타르성분인 2-피콜린 흡착 실험을 수행하였다. 2-피콜린 초기농도, 흡착 온도 및 시간을 달리한 회분식 흡착 평형 데이터를 Langmuir, Freundlich, Temkin, Dubinin-Radushkevich 등온흡착식에 적용하였다. 실로퓨트를 이용한 2-피콜린의 흡착은 Langmuir 흡착등온식에 가장 적합함을 알 수 있었다. 흡착온도가 증가함에 따라 흡착용량이 감소하는 경향을 보였으며 실로퓨트를 이용한 2-피콜린 흡착 공정이 적합함을 알 수 있었다. 동역학적 해석을 통하여 본 흡착 공정은 유사 이차 반응속도식에 잘 따름을 알 수 있었으며, 입자 내 확산과 경계층 확산이 율속 단계에 거의 영향을 미치지 않았다. 열역학적 해석을 통해 흡착 과정이 발열이며, 비가역적 비자발적으로 수행되었다. 흡착량이 증가함에 따라 등량흡착열은 감소하는 경향을 보여 흡착제의 표면 에너지가 불균일함을 알 수 있었다.

Enhanced Production of Digoxin by Digitoxin Biotransformation Using In Situ Adsorption in Digitalis lanata Cell Cultures

  • Hong, Hee-Jeon;Lee, Jong-Eun;Ahn, Ji-Eun;Kim, Dong-Il
    • Journal of Microbiology and Biotechnology
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    • 제8권5호
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    • pp.478-483
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    • 1998
  • For the enhanced production of a cardiac glycoside, digoxin, using in situ adsorption by biotransformation from digitoxin in plant cell suspension cultures, selection of proper resins was attempted and the culture conditions were optimized. Among various kinds of resins tested, Amberlite XAD-8 was found to be the best for digoxin production in considering adsorption characteristics as well as the effect on cell growth. Adequate time for resin addition was determined to be 36 h from the beginning of biotransformation and the presence of resins should be as short as possible to increase the productivity. In addition, to prevent the cells from direct contact with resin particles, immobilized systems were designed and examined. Immobilization further improved the advantages of in situ adsorption. It was confirmed that the increase of the contact area for mass transfer was an important factor in utilizing an immobilized system to enhance digoxin production.

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토양상에 의한 Trichloroethyene처리에 관한 연구 (A Study on Control of Trichloroethyene by Soil bed)

  • 이혜령;고경숙;임경택
    • 한국환경보건학회지
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    • 제24권3호
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    • pp.41-47
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    • 1998
  • The purpose of this research is evaluation of adsorption capacity of the cast for TCE comparing with the yellow clay. Furthermore, the experimental data was fitted with the Langmuir and Freundlich isotherm and was found to be apllicable to the adsorption isotherm equation. The soil bed reactor used in this study was made of glass(10 cm in diameter, 100 cm in depth). The cast and yellow clay used as adsorbents were screened with 8-20 mesh mecanically. Results from Equilibrium test with adsorbents showed that the equibrium time of the cast and yellow clay was 9min independent of the amount of the adsorbents. The adsorption efficiencys of the cast and yellow clay for TCE was 66.3% and 56.2%, respectively. In the application of Freundlich isotherm, 1/n of the cast and yellow clay were 0.786 and 0.704, respectively. These results showed that the cast was more available than the yellow clay as TCE adsorbent. The best adsorption capacity was showed at 0% moisture content, 70 ppm inlet concentration and 25$^{\circ}$C temperature.

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Adsorption of cationic dye (MB) and anionic dye (AG 25) by physically and chemically activated carbons developed from rice husk

  • Youssef, A.M.;Ahmed, A.I.;El-Bana, U.A.
    • Carbon letters
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    • 제13권2호
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    • pp.61-72
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    • 2012
  • Dye removal from waste water via adsorption by activated carbons (ACs) developed from agricultural wastes represents an ideal alternative to other expensive treatment options. Physical and chemical ACs were prepared from rice husks. The textural properties of the ACs were characterized by Brunauer-Emmett-Teller-$N_2$ adsorption and scanning electron microscopy. The chemistry of the carbon surface was investigated by Fourier transform infrared spectroscopy, base and acid neutralization capacities, pH of the active carbon slurry, and $pH_{pzc}$. The adsorption capacities of the ACs for the basic dye (methylene blue) and acid dye (acid green 25) were determined using parameters such as contact time, pH, and temperature. NaOH-ACs showed the highest surface area and total pore volume, whereas steam-ACs showed the lowest ones.

Adsorption of Uranium (VI) Ion on 1-Aza-12-Crown-4 Synthetic Resin with Styrene Hazardous Material

  • Kim, Joon-Tae
    • 통합자연과학논문집
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    • 제6권2호
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    • pp.104-110
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    • 2013
  • 1-Aza-12-crown-4 macrocyclic ligand was combined with styrene (2th petroleum in 4th class hazardous materials) divinylbenzene copolymer having 1%, 2%, 3%, and 6% crosslinks by a substitution reaction, in order to synthesize resin. These synthetic resins were confirmed by chlorine content, elementary analysis and IR-spectrum. As the results of the effects of pH, equilibrium arrival time, crosslink of synthetic resin, and dielectric constant of a solvent on uranium ion adsorption for resin adsorbent, the uranium ion showed high adsorption at pH 3 or over and adsorption equilibrium of uranium ion was about 2 hours. In addition, adsorption selectivity for the resin in methanol solvent was the order of uranium ($UO_2{^{2+}}$) > iron ($Fe^{3+}$) > lutetium ($Lu^{3+}$) ions, adsorbability of the uranium ion was in the crosslinks order of 1%, 2%, 3%, and 6% was increased with the lower dielectric constant.

반도체 제조공정의 폐수슬러지로 합성된 Hydroxyapatite를 이용한 인산이온의 흡착 (The Adsorption of Phosphate Son Using Hydroxyapatite synthesized by Wastewater Sludge of Semiconductor Fabrication Process)

  • 강전택;정기호;신학기
    • 한국환경과학회지
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    • 제11권3호
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    • pp.257-262
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    • 2002
  • The hydroxyapatite(HAp) for the present study was prepared with the wastewater sludge from semiconductor fabrication process and it was crystallized in an electric furnace for 30 min at 90$0^{\circ}C$. The adsorption characteristics of HAp for phosphate ion in aqueous solution has been investigated. The adsorbed ratio of phosphate ion for HAp were investigated according to the reaction time, amount of HAp, concentration of standard solution, pH of solution, and influence of concomitant ions. The amount of adsorbed phosphate ion decreased with the increase of pH due to the mutual electrostatic repulsion between adsorbed phosphate ions and competitive adsorption between phosphate ion and OH- ion in aqueous solution. The maxium amount of the adsorption equilibrium for phosphate ion was about 24 mg/g of HAp. The HAp would likely to be a possible adsorbent for the removal of phosphate ion in the waste water.

Low concentration cadmium removal using weathered sand of basalt

  • Park, Jae Hong;Lee, Jae Kwan;Shin, Dong Seok
    • Membrane and Water Treatment
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    • 제12권2호
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    • pp.51-58
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    • 2021
  • The natural weathered sand of basalt (WSB) has been used for the removal of cadmium from aqueous solution. The influence of various parameters i.e., contact time, pH, weathered sand of basalt dosage, particle size of the weathered sand of basalt, temperature and initial cadmium concentration were analyzed. Cadmium adsorption kinetics was well described by the pseudo second order model. Adsorption equilibrium for cadmium was properly well fitted to Langmuir isotherm model with maximum adsorption capacity 0.50 mg/g. Compared with the other experimental results using various kinds of adsorbents at a low concentration (1.0 mg/L or so) similar to that of this study, the cadmium removal efficiency using weathered sand of basalt was higher. It has been demonstrated that weathered sand of basalt has a available alternative adsorbent for cadmium when its initial concentration is low.

활성탄소섬유상에서 CH4/CO2 혼합가스의 흡착 특성 (Adsorption Characteristics of $CH_4/CO_2$ Mixed Gases on Activated Carbon Fibers)

  • 문승현;심재운
    • 한국대기환경학회지
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    • 제20권5호
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    • pp.655-662
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    • 2004
  • An adsorption process to recover the pure $CH_4\;and\;CO_2$ from its mixture was examined. In this study, activated carbon fibers were used as a selective adsorbent. The activated carbon fibers has 78~94% micropore volume and 10.5~20.3${\AA}$ narrow pore size, and showed high adsorption rate and the good selectivity for $CO_2$ under the ambient pressure. The ACF with high surface area showed short mass transfer zone and long breakthrough time and, its adsorption capacity depended on the microporosity. Compared with single component adsorption, the amount adsorbed $CO_2$ on ACF increased by the roll-up of $CH_4$ in mixed gases. The adsorption selectivity increased as now rate and $CO_2$ concentration of mixed gases increased, showing 5.2 selectivity for 75% $CO_2$ concentration.

토양중 Pendimethalin의 흡착 및 이동특성 (The Adsorption and Movement Characteristics of Pendimethalin in Soils)

  • 라덕관;김영규
    • 한국토양환경학회지
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    • 제5권3호
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    • pp.17-23
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    • 2001
  • 토양중 pendimethalin의 흡착과 이동특성을 파악하기 위하여 사양토, 미사질토 및 양토를 대상으로 회분식 및 칼럼식 실험을 통하여 얻어진 결과는 다음과 같다. Pendimethalin은 진탕 6시간에서 사양토의 경우 59.6%, 미사질토의 경우 77.3%, 양토의 경우 64.0%가 흡착되어 평형흡착에 근접하는 경향을 나타냈으며, 흡착등온식은 Freundlich식에 잘 일치하였으나, Langmuir식에는 적합하지 않았다. 사양토, 미사질토 및 양토에 대한 pendimethalin의 흡착계수는 각각 8.0, 16.1, 9.5로 나타났다. 흡착칼럼 배출구에서 pendimethalin이 처음 검출된 시간 및 유출량은 사양토의 경우 112min. 700ml, 미사질토의 경우 630min, 2100m1, 양토의 경우 189min, 900ml이었다. 0.05Co를 파과점으로 할 경우 각 토양의 파과점에 도달되는 시간은 각각 256min, 810min, 420min이었다.

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섬유상활성탄에 의한 THMs 및 THMs 전구물질의 흡착특성 (Adsorption of THMs and THM Precursors on Activated Carbon Fibers)

  • 한명호;이진식;윤이용
    • 상하수도학회지
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    • 제10권1호
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    • pp.121-130
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    • 1996
  • Adsorption isotherms of three trihalomethanes(THMs: $CHCl_3$, $CHBrCl_2$ and $CHBr_2Cl$) and the other organics(p-chlorophenol and sucrose)on activated carbon fibers(ACFs) were measured. Adsorption capacities of the ACFs for these THMs were found to be comparable with or slightly larger than those of granular activated car bons(GACs) which have been widely used for trihalomethanes control in drinking water. Also, the breakthrough curve prediction was successfully carried out using a mathematical model on basis of the assumption that the adsorption equilibrium is instantaneously established when a THM solution contacts the ACF. In practice, THM removal from drinking water was investigated at water works using benchscale ACF adsorptJOn columns. The volume of water treated at a space velocity(SV) of about $100h^{-1}$ was approximately 40 l/g-ACF. The practical adsorption capacities of PCP and sucrose in column adsorption were in good agreement with those of theoretically calculated results using the batch adsorption measurments. And the saturation time model of these substrates in the columns was also agreed succesfully with practical measurments.

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