• Title/Summary/Keyword: Adsorption Time

검색결과 1,215건 처리시간 0.029초

수액제에 유입되는 실내 유기오염물질의 거동 (Behavior of Indoor Organic Pollutants Dissolved into the Ringer's Solution)

  • 김만구;정영림
    • 한국대기환경학회지
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    • 제12권3호
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    • pp.315-322
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    • 1996
  • Recently, hospital acquired infections have an increase interest as a public problems, which are caused of indoor pollutants in hospital. Microorganisms, ethylene oxide, formaldehyde, and anesthetic gases are main hazardous pollutants in hospital. The possible pathways of the infection are a respiratory channel as well as a blood channel. The blood channel is concerned since these pollutants might be dissolved into the Ringer's solution. The objective of this research was to evaluate the removal efficiencies of adsorption trap for formaldehyde and microorganisms as indoor pollutants which permeated into the Ringer's solution. Dissolved formaldehyde in the solution was increased with the injection dose time. The amount of dissolved formaldehyde was 67.5 $\pm$ 9.5% in Ringer's solution when injection dose time was controlled about 7hrs. An adsorption trap was designed for preventing formaldehyde and microorganisms to be permeated into Ringer's solution. The adsorption trap was packed with 0.4g of active carbon (60/80 mesh) in a sterilized plastic tube (7.79 cm length, 0.46 cm i.d.) and both ends were packed with glass wool. Devised infusion set equipped with the adsorption trap showed 99.9% of removal efficiency for formaldehyde. Microorganism numbers detected on sterilized water for injection and 5% dextrose infusion used in the hospital were 2,695 $\times 10^3$ cells/l and 4,190 $\times 10^3$ cells/l, respectively. Removal efficiency by the adsorption trap was 92.3 $\pm$ 8.5% as for microorgnisms.

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습식공법으로 제조한 목탄-목재섬유복합재료의 에틸렌가스 흡착력과 과일 신선도 유지 효과 (Ethylene gas adsorption capacity and preserving effect of fruit freshness of Charcoal-fiberboard by wet forming process)

  • 이화형;김관의
    • 한국가구학회지
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    • 제14권1호
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    • pp.1-9
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    • 2003
  • This research was carried out for packing materials and building materials to examine thylene gas adsorption and effect of keeping fruit fresh of wet formed charcoal-fiber mposite made from defibrated fiber of Pinus densiflora Sieb. et Zucc. and white charcoal from uercus variabilis Bl.(wood fiber: charcoal=8:2, 6:4, 4:6, 2:8), with/without phenol formaldehyde resin(PF, Non volatile content:$52\%$, resin content $1,3,5\%$). The results are summarized as follows: 1. The higher the charcoal content, the more the ethylene gas adsorption. At the same mixing ratio of fiber to charcoal, $\#100-200$ of charcoal particle size gave the better reslts than $\#60-100$. 2. Adding PF into the charcoal fiber composite decreased the capacity of ethylene gas adsorption but there was no significant difference until $5\%$ adding amount of PF. 3. For keeping fruit fresh for a long time, Charcoal fiber composite was $66\%$ longer than control. The higher the white charcoal content, the longer fresh time.

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Surface and Adsorption Properties of Activated Carbon Fabric Prepared from Cellulosic Polymer: Mixed Activation Method

  • Bhati, Surendra;Mahur, J.S.;Dixit, Savita;Choubey, O.N.
    • Bulletin of the Korean Chemical Society
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    • 제34권2호
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    • pp.569-573
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    • 2013
  • In this study, activated carbon fabric was prepared from a cellulose-based polymer (viscose rayon) via a combination of physical and chemical activation (mixed activation) processes by means of $CO_2$ as a gasifying agent and surface and adsorption properties were evaluated. Experiments were performed to investigate the consequence of activation temperature (750, 800, 850 and $925^{\circ}C$), activation time (15, 30, 45 and 60 minutes) and $CO_2$ flow rate (100, 200, 300 and 400 mL/min) on the surface and adsorption properties of ACF. The nitrogen adsorption isotherm at 77 K was measured and used for the determination of surface area, total pore volume, micropore volume, mesopore volume and pore size distribution using BET, t-plot, DR, BJH and DFT methods, respectively. It was observed that BET surface area and TPV increase with rising activation temperature and time due to the formation of new pores and the alteration of micropores into mesopores. It was also found that activation temperature dominantly affects the surface properties of ACF. The adsorption of iodine and $CCl_4$ onto ACF was investigated and both were found to correlate with surface area.

키토산비드를 이용한 양이온/음이온의 흡착모델 적용 (Applicability of adsorption kinetic model for cation/anion for chitosan hydrogel bead)

  • 안병렬
    • 상하수도학회지
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    • 제33권3호
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    • pp.205-213
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    • 2019
  • Batch adsorption tests were performed to evaluate the applicability of adsorption kinetic model by using hydrogel chitosan bead crosslinked with glutaraldehyde (HCB-G) for Cu(II) as cation and/or phosphate as anion. Pseudo first and second order model were applied to determine the sorption kinetic property and intraparticle and Boyd equation were used to predict the diffusion of Cu(II) and phosphate at pore and boundary-layer, respectively. According to the value of theoretical and experimental uptake of Cu(II) and phosphate, pseudo second order is more suitable. On comparison with the value of adsorption rate constant (k), phosphate kinetic was 2-4 times faster than that of Cu(II) at any experimental condition indicating the electrostatic interaction between ${NH_3}^+$ and phosphate is dominated at the presence of single component. However, when Cu(II) and phosphate simultaneously exist, the value of k for phosphate was sharply decreased and then the difference was not significant. Both diffusion models confirmed that the sorption rate was controlled by film mass transfer at the beginning time (t < 3 hr) and pore diffusion at next time section (t > 6 hr).

Selective adsorption of Ba2+ using chemically modified alginate beads with enhanced Ba2+ affinity and its application to 131Cs production

  • Kim, Jin-Hee;Lee, Seung-Kon
    • Nuclear Engineering and Technology
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    • 제54권8호
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    • pp.3017-3026
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    • 2022
  • The 131Cs radioisotope with a short half-life time and high average radiation energy can treat the cancer effectively in prostate brachytherapy. The typical 131Cs production processes have a separation step of the cesium from 131Ba to obtain a high specific radioactivity. Herein, we suggested a novel 131Cs separation method based on the Ba2+ adsorption of alginate beads. It is necessary to reduce the affinity of alginate beads to cesium ions for a high production yield. The carboxyl group of the alginate beads was replaced by a sulfonate group to reduce the cesium affinity while reinforcing their affinity to barium ions. The modified beads exhibited superior Ba2+ adsorption performances to native beads. In the fixed-bed column tests, the saturation time and adsorption capacity could be estimated with the Yoon-Nelson model in various injection flow rates and initial concentrations. In terms of the Cs elution, the modified alginate showed better performance (i.e., an elution over 88%) than the native alginate (i.e., an elution below 10%), indicating that the functional group modification was effective in reducing the affinity to cesium ions. Therefore, the separation of cesium from the barium using the modified alginate is expected to be an additional option to produce 131Cs.

Evaluation of Design of Experiments to Develop MOF-5 Adsorbent for Acetylene Capture

  • Min Hyung Lee;Sangmin Lee;Kye Sang Yoo
    • Korean Chemical Engineering Research
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    • 제61권2호
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    • pp.322-327
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    • 2023
  • A design of experiments was evaluated in optimizing MOF-5 synthesis for acetylene adsorption. At first, mixture design was used to optimize precursor concentration, terephthalic acid, zinc acetate dihydrate and N,N-dimethylformamide. More specifically, 13 conditions with various molar ratios were designed by extreme vertices design method. After preparing the samples, XRD, N2 physisorption and SEM analysis were performed for their characterization. Moreover, acetylene adsorption experiments were carried out over the samples under identical conditions. The optimal precursor composition for MOF-5 synthesis was predicted on a molar basis as follows: terephthalic acid : acetate dihydrate : dimethylformamide = 0.1 : 0.4 : 0.5. Thereafter, multi-level factorial design was designated to investigate the effect of synthesis reaction conditions such as temperature, time and stirring speed. By the statistical analysis of 18 samples designed, 4 reaction parameters were determined for additional adsorption experiments. Therefore, MOF-5 prepared under the synthesis time and temperature of 100 ℃ and 12 h, respectively, showed the maximum adsorption capacity of 15.1 mmol/g.

에너지 효율 향상을 위한 열전소자를 이용한 흡·탈착 시스템 개발 연구 (A Study on the Development of Adsorption-Desorption Systems Using Thermoelectric Devices for Improved Energy Efficiency)

  • 유직수
    • 한국산업융합학회 논문집
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    • 제27권4_2호
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    • pp.981-989
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    • 2024
  • In recent years, there has been a growing focus on preserving the global environment and utilizing resources efficiently. The significance of energy conservation has led to the development of systems that recycle waste heat from factories and use eco-friendly refrigerants. This study aims to enhance the performance of adsorption-desorption systems using thermoelectric devices, which are known for their ability to convert temperature differences into electrical energy. The research focuses on improving the efficiency of these systems by integrating thermoelectric modules to cool the adsorption side and heat the desorption side, thus enhancing overall system performance. The experiments utilized a typical thermoelectric device and silica gel as the adsorbent. Key experimental parameters included varying the inlet air temperature and relative humidity on the desorption side. The results indicated that increasing the relative humidity of the inlet air on the desorption side significantly enhanced the overall mass transfer coefficient while reducing the completion time of the process. Similarly, higher inlet air temperatures led to an increase in the mass transfer coefficient and a decrease in process completion time. These findings suggest that optimizing the operational conditions of thermoelectric devices can substantially improve the performance of adsorption-desorption systems, offering potential benefits for applications in ventilation systems and other related fields.

소수성 다공성 평막의 표면 친수화를 통한 막성능 향상 (Enhancement of Membrane Performance through Surface Hydrophilization of Hydrophobic Porous Flat-sheet Membranes)

  • 김백암;이학민;이보성;김성표;정성일;임지원
    • 폴리머
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    • 제35권5호
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    • pp.438-443
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    • 2011
  • 소수성 막의 파울링 현상 개선, 젖음성 향상을 통한 투과도 증가 등을 위하여 poly(vinyl amine), poly(styrene sulfonic acid), poly(vinyl sulfonic acid), 그리고 poly(acrylamide-co-acrylic acid) 등의 다양한 흡착소재를 polyethylene(PE) 다공성막 표면에 흡착용액 농도, 흡착시간, 염의 종류, 이온세기 등을 변화시키면서 순수 투과도를 측정하였다. 일반적으로 흡착용액의 농도, 흡착시간, 그리고 이온세기가 증가하면 투과도는 초기에 증가하다가 감소하는 경향을 보였다. Poly(vinyl sulfonic acid) 1000 ppm, $Mg(NO_3)_2$의 이온세기 0.1, 그리고 흡착시간 150초 조건에서 순수투과도가 35% 향상된 375 $L/m^2h$(LMH)를 얻었으며, poly(styrene sulfonic acid) 1000 ppm, NaCl의 이온세기 0.1과 0.2, 그리고 흡착시간 60초에서 각각 50%(411 LMH), 35%(374 LMH)의 순수 투과도 증가율을 보였다.

수용액 중 극미량 니켈(II)과 아연(II)의 흡착농축 및 ICP-AES 정량에 관한 연구 (Adsorptive Preconcentration and ICP-AES Determination for Trace Amount of Ni(II) and Zn(II) in Aqueous Solution)

  • 최종문;최선도
    • 한국환경보건학회지
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    • 제31권1호
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    • pp.73-78
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    • 2005
  • A determination method of trace Ni(II) and Zn(II) in aqueous solution was studied and developed by adsorbing on titanium dioxide. For this purpose, several conditions were optimized such as the pH of sample solution, adsorption time, the types and concentration acid, and desorption time. The titanium dioxide was added in sample solution which was pH adjusted. Then, the sample solution was stirred for 5 minutes. This mixture was stored in room temperature for 30 minutes to allow adsorption. After filtering and washing the titanium dioxide, the analytes were dissolved from the titanium dioxide on membrane filter by an ultrasonic vibration for 10 minutes in 1.0 M $HNO_3$ solution. Then, this sample solution was analysed using ICP-AES. The adsorption equilibrium was achieved in 30 minutes. The desorption was the most of effective with 1.0 M(mol/l) nitric acid solution, and desorption time was 10 minutes. This procedure was applied for the analysis of two real samples, i.e., brown seaweed and tangle. The recoveries of Ni(II) and Zn(II) in spiked samples were 89.4${\sim}$98.9% for analytes.

NMO를 이용한 이동층반응기에서의 $SO_2$ 흡착특성에 관하 연구 (A Study on $SO_2$ Adsorption Characteristics by NMO in a Moving Bed Reactor)

  • 조기철
    • 한국대기환경학회지
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    • 제16권4호
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    • pp.399-408
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    • 2000
  • This study evaluated the SO2 adsorption characteristics using a continous moving bed system. Natural manganese oxide (NMO) reaction condition such as L/D the starting time of the NMO feed, feed rate, and flow rate of simulated flue gas, and NMO size were tested. The results showed that optimum L/D was 1.0 in this moving bed system. The higher the feeding rate was the higher the SO2 removal efficiency was and the higher the flow rate of simulated flue gas was the shorter the time to reach the euqilibirum concentration was. The final SO2 con-centration when it reaches the equilibrium concentration was not affected by the starting time of the NMO feed.

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