• Title/Summary/Keyword: Sorption

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Radionuclide Sorption in the Geosphere: Role of Single Minerals (지하매질에서의 방사성핵종흡착: 단일광물의 역할)

  • Cho, Young-Hwan;Hyun, Sung-Pil;Hahn, Pilsoo
    • Proceedings of the Mineralogical Society of Korea Conference
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    • 2001.06a
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    • pp.40-40
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    • 2001
  • The sorption behavior of Cs(I), Sr(II), and U(VI) on representative single minerals(oxide and clay) and rocks were comparatively studied by using batch type sorption experiment. The effects of pH, ionic strength and the sorption mechanism were also discussed. It was found that mineral structure played as a main factor governing the sorption characteristics of Cs(I), Sr(II). The sorption of Cs(I) and Sr(II) on minerals showed ionic strength-dependency, which is a indirect sign of weak binding between metal cation and mineral surfaces. However, the sorption behavior of U(VI) was quite different compared with that of Cs(I), and Sr(II). Fe-oxide minerals showed strong tendency for U(VI) sorption, dominating the sorption in the composite/mixture systems. The surface characteristics which arise from mineral structure, and the affinity of metal ions to the sorption sites of minerals are the key to understand the role of minerals in the radionuclide sorption.

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Sorption of Organic Penetrants by Amorphous Polyamide (비결정 폴리아마이드에 대한 유기화합물의 흡착 특성 연구)

  • Lee, Myung-Hoon
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.4 no.1
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    • pp.11-16
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    • 1997
  • Sorption studies involving the sorption of n-propanol by an Amorphous Nylon(Nylon 6I/6T) were carried out as a function of sorbate vapor activity at $23^{\circ}C$. Vapor activity levels from 0.035 to 0.91 were investigated to evaluate the concentration dependency of sorption mechanism. Sorption behavior of propanol by Nylon 6I/6T showed distinctive two mode sorption phenomena as a function of Vapor activity. At Vapor activity levels below a=0.11, equilibrium sorption was achieved within a short period of time(less than 20hrs), which can be interpreted as following a Fickian diffusion model. A Langmuir-Flory-Muggins Dual Mode Sorption model can also be applied at these concentration levels. However, for Vapor activities above a=0.11, the sorption process appeared to be non-Fickian and resulted in a lack of equilibrium being attained.

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A Study on Adsorption of Lead(II) in Wastewater Using Natural Kaolinite (천연 고령토의 폐수 중 납 흡착에 관한 연구)

  • 이종은
    • Journal of Environmental Health Sciences
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    • v.21 no.3
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    • pp.77-86
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    • 1995
  • Lead(II) removal efficiency by natural kaolinite was investigated through laboratory experiments. This study was conducted in two phases-sorption and desorption. In the adsorption study, the influence of sorption kinetics and sorption isotherm and various parameters such as pH, temperature, coexisting other heavy metal ions on the lead adsorption was investigated. And desorption study was carried out in order to find the re-usability of kaolinite as an adsorbent. The results of the study are as follows. 1. Sorption kinetics was investigated under the condition of 2.5 mg/l adsorbent concentration, pH 6.5$\pm$0.05, temperature $30\pm 0.5\circ$C, initial lead(II) concentration 25 mg/l. Adsorption rate was initially rapid and the extent of adsorption arrived at adsorption equilibrium with 73% adsorption efficiency in an hour. 2. The sorption isotherm experiment was made with different initial lead(II) concentration. A linearized Freundlich equation was used to fit the acquired experimental data. As a result, Freundlich constants, the sorption intensity (1/n) was 0.47 and the measure of sorption (k) was 2.44. So, it was concluded that sorption of lead(II) by kaolinite is effective. 3. The effect of pH on lead(II) sorption by kaolinite shows that at a pH of 3, only 6% of the total lead(II) was adsorbed and at a pH 9, 97% of the lead(II) was removed. And the effect of temperature on lead(II) sorption by kaolinite shows that as the temperature increased, the amount of lead(II) sorption per unit weight of kaolinite increased. But the effect was minor (p<0.05). 4. Sorption isotherm of lead coexisting cadmium (II) or zinc (II) was lower than that of lead itself. It was caused by the result of competitive sorption to adsorption site. And there was no difference between the sorption isotherm of cadmium and zinc. 5. In desorption studies, only 5.12% desorption took place in distilled water, while 52.08% in 0.1 N hydrochloric acid. Consequently used kaolinite could be regenerated by hydrochoric acid.

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Assessment of Sorption Behavior on Slag Against Heavy Metals (카드뮴, 납, 구리에 대한 슬래그의 흡착특성평가)

  • Lee, Gwang-Hun;Choi, Sung-Dae;Chung, Jae-Shik;Park, Jun-Boum;Nam, Kyoung-Phile
    • Journal of the Korean Geotechnical Society
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    • v.24 no.6
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    • pp.17-25
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    • 2008
  • Permeable reactive barriers (PRBs) technology can be applied to contaminated groundwater remediation. It is necessary to select adequate reactive material according to contaminant characterization. In groundwater. In this research, the reaction between reactive material and heavy metal contaminants was estimated through batch test. Reactive material was slag, which has been produced in Gwangyang power plant, and heavy metal contaminants were cadmium, lead and copper. Batch test consisted of two testes: 1) sorption equilibrium test and 2) sorption kinetic test. Sorption equilibrium test was performed for estimating slag sorption capacity against contaminants. And sorption kinetic test was performed for slag sorption rate with contaminants species, contaminants initial concentration and sulfate. Sorption capacity and sorption rate were affected by contaminant species. Sorption rate increased with increasing initial concentration in lead and copper but decreased with increasing initial concentration in cadmium. Sorption rate increased in existing sulfate. In low concentration, film diffusion was domain mechanism, and in high concentration, particle diffusion was domain mechanism.

Potential Application of Environmental Tracer in Hydrogeochemistry Using Sorption Properties (환경 추적자의 흡착 특성을 이용한 수리지화학적 활용 가능성 고찰)

  • Choung, Sungwook;Chang, Seeun;Kim, Minkyung;Kim, Sungpyo;Um, Wooyong
    • Journal of Soil and Groundwater Environment
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    • v.17 no.6
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    • pp.59-68
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    • 2012
  • This study provided sorption properties of chlorofluorocarbons (CFCs), and elucidated potential application of CFC sorption data in hydrogeochemistry. Prior sorption studies were reviewed for hydrophobic organic compounds similar to the CFCs, because there were only few CFC sorption studies. The CFCs are regarded as relatively conservative chemicals in groundwater environments based on their moderate hydrophobicity. However, thermally altered carbonaceous matter (TACM) can significantly increase sorption capacity and nonlinearity for hydrophobic organic compounds such as CFCs, compared to general soil organic matter. CFC sorption behavior are close to the sorption for reviewed organic chemicals. Therefore, the CFC sorption data can be used for determining hydrogeochemical properties and predicting transport of organic contaminants in TACM-containing aquifer environments.

Sorption Isotherms and KocS Estimation of Pyrethroids in Sediments

  • Lee, Sang-Jin;Shin, Hyun-Moo
    • Journal of Environmental Science International
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    • v.12 no.11
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    • pp.1173-1179
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    • 2003
  • Laboratory sorption isotherm batch studies have been attempted to elucidate interaction of synthetic pyrethroids (bifenthrin and permethrin) with sediments and their fractions. As a nonlinear isothermal model, the Freundlich equation was applied to sorption results obtained from sediments to investigate the relationship between synthetic pyrethroids and sediments containing different amounts of organic carbon. Results demonstrated that the sorption capabilities of bifenthrin and cis- and trans-permethrin was in the order of bifenthrin, cis-permethrin and trans-permethrin, respectively, indicating that adsorbed bifenthrin was the most stable followed by cis- and trans-permethrin in all sediments. Their sorption capability was closely related to organic carbon contents in sediments. Higher sorption was observed in sediments containing higher organic carbon contents. Sorption study extended into the fractions, clay and humic acids, extracted from a sediment, indicated that higher sorption capacity in humic acids occurred than in the clay of both examined bifenthrin and permethrin. This study demonstrates the sorption of synthetic pyrethroids with sediments, and will help in the understanding of the transport and fate of synthetic pyrethroids existing in field sediments.

Prediction model of 4.5 K sorption cooler for integrating with adiabatic demagnetization refrigerator (ADR)

  • Kwon, Dohoon;Kim, Jinwook;Jeong, Sangkwon
    • Progress in Superconductivity and Cryogenics
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    • v.24 no.1
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    • pp.23-28
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    • 2022
  • A sorption cooler, which utilizes helium-4 as a working fluid, was previously developed and tested in KAIST. The cooler consists of a sorption pump and a thermosyphon. The developed sorption cooler aims to pre-cool a certain amount of the magnetic refrigerant of an adiabatic demagnetization refrigerator (ADR) from 4.5 K to 2.5 K. To simulate the high heat capacitance of the magnetic refrigerant, liquid helium was utilized not only as a refrigerant for the sorption cooling but also as a thermal capacitor. The previous experiment, however, showed that the lowest temperature of 2.7 K which was slightly higher than the target temperature (2.5 K) was achieved due to the radiation heat leak. This excessive heat leak would not occur when the sorption cooler is completely integrated with the ADR. Thus, based on the experimentally obtained pumping speed, the prediction model for the sorption cooler is developed in this study. The presented model in this paper assumes the sorption cooler is integrated with the ADR and the heat leak is negligible. The model predicts the amount of the liquid helium and the required time for the sorption cooling process. Furthermore, it is confirmed that the performance of the sorption cooler is enhanced by reducing the volume of the thermosiphon. The detailed results and discussions are summarized.

Sorption of Se(-II) on illite, MX-80 bentonite, shale, and limestone in Na-Ca-Cl solutions

  • Walker, Andrew;Racette, Joshua;Saito, Takumi;Yang, Tammy (Tianxiao);Nagasaki, Shinya
    • Nuclear Engineering and Technology
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    • v.54 no.5
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    • pp.1616-1622
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    • 2022
  • Selenium has been identified as an element of interest for the safety assessment of a deep geological repository (DGR) for used nuclear fuel. In Canada, groundwaters at DGR depths in sedimentary rocks have been observed to have a high ionic strength. This paper examines the sorption behavior of Se(-II) onto illite, MX-80 bentonite, Queenston shale, and argillaceous limestone in Na-Ca-Cl solutions of varying ionic strength (0.1-6 mol/kgw (m)) and across a pH range of 4-9. Little ionic strength dependence for Se(-II) sorption onto all solids was observed except that sorption at high ionic strength (6 m) was generally slightly lower than sorption at low ionic strength (0.1 m). Illite and MX-80 exhibited the expected results for anion sorption, while shale and limestone exhibited more constant sorption across the pH range tested. A non-electrostatic surface complexation model successfully predicted sorption of Se(-II) onto illite and MX-80 using the formation of an inner-sphere surface complex and an outer-sphere surface complex. Optimized values for the formation reactions of these surface species were proposed.

Evaluation of Antifungal Performance of Wallpapers According to Sorption Properties (벽지의 흡.방습 특성에 따른 항곰팡이 성능 평가)

  • Moon, Hyeun-Jun;Kim, Kyeong-Min;Ryu, Seung-Ho
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.29 no.7
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    • pp.247-254
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    • 2013
  • The hygric properties of building materials are related to condensation phenomena and biological contaminants such as fungi infestations, especially in building environments. If the relationship between mould growth and hygric properties is identified and the appropriate building materials are used indoor, it can protect indoor environment from infection of mould. The purpose of this study is to find the relationships between sorption properties and mould germination/growth on wallpapers. An experimental study was conducted to characterize the sorption properties of the selected wallpapers. The sorption properties of the selected wallpapers were obtained at various relative humidity conditions. Then, the selected wallpapers were inoculated with three fungi species and mould germination/growth rates were observed. The correlations between sorption properties and mould germination/growth rate were analyzed. The results showed that the wallpapers that had high sorption properties, which resulted in higher antifungal performance compared to the wallpapers with lower sorption properties.

Theoretical Analysis on the Heat and Mass Transfer in a Sorption Cool Pad (흡습 냉각 패드에서의 열 및 물질전달에 관한 연구)

  • 황용신;이대영;박봉철
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.2
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    • pp.167-174
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    • 2004
  • A sorption cool pad brings cooling effect without any pre-cooling, nor any external energy supply. It uses evaporative cooling effect stimulated by the desiccative sorption. In this paper, heat and mass transfer in the sorption cool pad are investigated theoretically. The evaporative cooling process caused by the desiccant is modeled and analyzed considering the sorption characteristics of the desiccant. Two nondimensional parameters are found to dominate the cooling process: one is related to the psychrometric characteristics and the other is to the sorption capacity of the desiccant. The former decides the time to reach the lowest temperature and the later controls the time duration of the cooling effect being sustained.