• Title/Summary/Keyword: membrane processes

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Enantiospecific Membrane Processes

  • Giorno, Lidietta
    • Korean Membrane Journal
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    • v.1 no.1
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    • pp.38-42
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    • 1999
  • Membrane technology can be applied in two ways to produce pure enantiomers. In one case a membrane separation process can be cmbined with an enantiospecific reaction to obtain so-called 'en-antiospecific membrane reacto' These systems are useful to carry out asymmetric synthesis or kinetic resolution and simulatneously separate the produced enantiomer. As for general membrane reactors the result is a more compact system with a higher conversion: in fact removal of a product drives equilibrium-limited reactions towards completion. The other way to apply membrane technology to chiral production is the use of intrinsically enantioselective membranes that are able to distinguish between two isomers favouring preferential transport of only one isomer in absence of reaction. In this paper the current development of chiral membrane processes will be discussed.

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ENANTIOSPECIFIC MEMBRANE PROCESSES

  • Giorno, Lidietta
    • Proceedings of the Membrane Society of Korea Conference
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    • 1999.07a
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    • pp.31-34
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    • 1999
  • Membrane technology can be applied in two ways to produce pure enantiomers. In one case, a membrane separation process can be combined with an enantiospecific reaction to obtain so-called 'enantiospecific membrane reactor'. These systems are useful to carry out asymmetric synthesis or kinetic resolution and simultaneously separate the produced enantiomer. As for general membrane reactors, the result is a were compact system with a higher conversion; in fact, removal of a product drives equilibrium-limited reactions towards completion. The other way to apply membrane technology to chiral production is the use of intrinsically enantioselective membranes that are able to distinguish between two isomers favouring preperential transport of only one isomer in absence of reaction. In This paper, the current development of chiral membrane processes will be discussed.

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A study on mitigation of membrane fouling by ozonation/coagulation in ultrafiltration (오존산화/응집 혼성공정에 의한 UF 분리막의 막오염 저감에 관한 연구)

  • Kim, Geon-Youb;Kim, Min-Gue;Lee, Chang-Ha;Kim, Hyung-Soo;Kim, Ji-Hoon;Lee, Kyung-Il
    • Journal of Korean Society of Water and Wastewater
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    • v.31 no.2
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    • pp.161-168
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    • 2017
  • Microfiltration (MF) and Ultrafiltration (UF) membrane processes capable of producing highly purified water have been extensively applied as a pretreatment process in the wastewater reuse field with the improvement of membrane properties and resistance, development of operating protocols, and improvement of technologies of backwashing and physicochemical cleaning, and improvement of scale and antifoulants. However, despite of the development of membrane production and process technologies, fouling still remains unresolved. This study confirmed that foulants such as polysaccharides, proteins and humic substances existed in final treated effluent (secondary effluent) by fluorescence excitation emission matrix (FEEM) and fourier transform infrared spectroscopy (FTIR) analysis. In addition, when constructing ozone oxidation and coagulation processes as a hybrid process, the removal efficiency was 5.8%, 6.9%, 5.9%, and 28.2% higher than that of the single process using coagulation in turbidity, color, dissolved organic carbon (DOC), and UV254, respectively. The reversible and irreversible resistances in applying the hybrid process consisting of ozone oxidation and coagulation processes were lower than those in applying ozone oxidation and coagulation processes separately in UF membrane process. Therefore, it is considered possible to apply ozonation/coagulation as a pretreatment process for stable wastewater reuse by and then contributing to the reduction of fouling when calculating the optimal conditions for ozone oxidation and coagulation and then to applying them to membrane processes.

New Membrane Module Design Using Dean Vortex Instability

  • ;Brewster, Mary E.;Belfort, Georges
    • Proceedings of the Membrane Society of Korea Conference
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    • 1992.10a
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    • pp.34-35
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    • 1992
  • Synthetic membrane processes are widely used in many industrial applications for concentrating and fractionating various components in solutions and suspensions. Advantages for using these processes include no phase change, direct separation without the use of additives, exploitation of large property differences.

Membrane Concentrate Thickening by Hollow-fiber Microfilter in Drinkin Water Treatment Processes

  • Lee, Byung-Ho
    • Korean Membrane Journal
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    • v.1 no.1
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    • pp.100-105
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    • 1999
  • A novel system to thicken the concentrated colloidal solution from membrane water treat-ment processes was developed. A hollow-fiber microfilter(hydrophilic polyethylene nominal pore size 0.1 ${\mu}$m total surface area 0.42 m2) was installed in an acrylic housing that has an aeration port 5 cm below the membrane and a clarifier in the bottom. The concentrate was uniformly supplied from the top of the housing. Bacuum filtration caused downward flow of concentrate and as a result thickening interface. The addition of poly-aluminum chloride (PAC) resulted in rapid increase of trans-membrane pressure (TMP) and in no improvement of the filtered water turbidity and thickening process. Two types of con-centrate and concentrate turbidity had little effect on the increase of TMP and concentrate thickening. It was observed that for the same height of membrane housing membrane surface area to housing volume (A/V) ratio had significant effect on the increase of TMP. When the housing volume was increased ten times the increasing rate of TMP was three times faster as compared to the original housing. A hydraulic model successfully simulated the formation and sedimentation of thickening interface.

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Advanced Water Treatment by UF/MF Membranes (UF/MF막을 이용한 고도수처리)

  • 김기협
    • Proceedings of the Membrane Society of Korea Conference
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    • 1997.06a
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    • pp.105-142
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    • 1997
  • We know very well the importance of water. Recently, we perceive the truth that water influence the quality of products and we must pay for it. Besides, we recognize why the water treatment is indispensable for life as well as industries. The variation of environment changes the natural resources and threatens the human life. Now, we cannot get water freely from nature. We should find new processes which are effective and inexpensive. We believe that the membrane technology can suggest the new way of water treatment. I'd like to explain the situation of water resource and the membrane processes by UF/MF membranes. I'll also introduce several case studies in this lecture. Till now, about 10 MF/UF systems were established in Korea. Of course, the usage of MF/UF for water treatment is beginning stage in Korea. But the future prospect is very good. Korean government has been developed various kinds of membrane processes for the purpose of drinking water, water reuse, development of new water resources and water related technologies, etc. In near future, maybe we will meet serious water problems, water deficiency and contamination. Fortunetely, we can suggest the membrane process for solving those problems. Membrane technology will be the base of clean technology.

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Present State of Membrane Filtration for Water Treatment in Japan

  • Kiso, Yoshiaki
    • Membrane Journal
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    • v.13 no.1
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    • pp.1-8
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    • 2003
  • Membrane filtration systems have been focusing and increasing rapidly in the filed of drinking water treatment because of several reasons. We describe briefly the present state of membrane filtration processes for drinking water treatment in Japan: including background, objectives, membrane suppliers, and some cases of actual plants.