• 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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    • 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 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.

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.

Mechanisms of Cu(II) Sorption at Several Mineral/Water Interfaces: An EPR Study

  • Cho, Young-Hwan;Hyun, Sung-Pil;Pilsoo Hahn
    • Proceedings of the Korean Magnetic Resonance Society Conference
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    • pp.72-72
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    • 2002
  • In most traditional sorption study in environmental conditions, experimental sorption data have been measured and interpreted by empirical ways such as partition coefficient and sorption isotherms. A mechanistic understanding of heavy metal interactions with various minerals (metal oxides, clay minerals) in aqueous medium is required to describe the behavior of radioactive metal ions in the environment. Various spectroscopic methods provide direct or indirect information on sorption mechanisms involved. We applied EPR (Electron Paramagnetic Resonance) spectroscopy to investigate the nature of metal ion sorption at water/mineral interfaces using Cu(II) as a spin probe. The major sorbed species and their motional state was identified by their EPR spectra. They showed distinct signals due to their strength of binding, local structure and motional state. The EPR results together with macroscopic sorption data show that sorption involved at least three different mechanisms depending on chemical environments (1).

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Experimental Study on Uranium Sorption onto Silica Colloids: Effects of Geochemical Parameters

  • Baik, Min-Hoon;Hahn, Pil-Soo
    • Nuclear Engineering and Technology
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    • v.33 no.3
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    • pp.261-269
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    • 2001
  • In this study, sorption experiments of uranium onto silica colloids were carried out and the effects of important geochemical parameters such as pH, ionic strength, carbonate concentration, colloid concentration, and total concentration of uranium were investigated. The sorption coefficients of uranium for silica colloids named as pseudo-colloid formation constants were about 10$^4$~ 10$^{5}$ mL/g depending on the experimental conditions. The effects of the geochemical parameters were found to be important in the sorption of uranium onto silica colloids. A Langmuir type sorption isotherm of uranium between silica colloids and the solution phase was also presented. The sorption mechanisms were explained by analyzing the effects of the geochemical parameters.

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Effects of solution, sorbate, and sorbent chemistries on polycyclic aromatic hydrocarbon sorption to hydrated mineral surfaces

  • Yim, Soobin
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • pp.132-135
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    • 2003
  • Solution chemistry, sorbate chemistry, and sorbent chemistry were widely investigated to find important factors that affect PAH sorption on mineral surfaces and to elucidate its microscopic mechanism. The solution chemistry, pH and ionic strength caused measurable change of HOC sorption reaction to minerals. The detectable change of Ka occurred at a pH region crossing the PZC (Point of Zero Charge) of each mineral. The PAH hydrophobicity, one of sorbate chemistry, was observed to have a strong correlation with PAM sorption to mineral. Mineral surface area was not found to be a predominant factor controlling PAH sorption. The mineral type might be more likely to play a crucial role in controlling the PAH sorption behavior. The CEC (Cation Exchange Capacity) of mineral, representing surface charge density, has meaningful correlation with regression slope of sorption coefficients (log $K_{d}$) versus aqueous activity coefficients (log Υ$_{w}$).).).

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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.