• Title/Summary/Keyword: reverse osmosis membrane

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Analysis of the Salt Separation and Concentration Using Counter-current Reverse Osmosis Spiral Wound Module (향류식 역삼투 나권형 모듈을 이용한 염분리농축 특성 해석)

  • 조한욱;민병렬;최광호
    • Membrane Journal
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    • v.4 no.3
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    • pp.142-151
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    • 1994
  • Counter-current type reverse osmosis spiral wound module was manufactured for the separation and concentration of salf solution. The ratio of permeate volumetric flow rate vs. brine volumetric flow rate was effective parameter between rejection and degree of cocentration. The reflection coefficient was correspondent to the relation between rejection and degree of cocentration by Spiegler-Kedem model. Counter-current reverse osmosis process had more osmotic pressure drop effect and more degree of concentration than general reverse osmosis process. As a result of computer calculation, the extension of module length than module diameter was more effective for the increase of degree of concentration.

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Pretreatment in Reverse Osmosis Seawater Desalination: A Short Review

  • Valavala, Ramesh;Sohn, Jin-Sik;Han, Ji-Hee;Her, Nam-Guk;Yoon, Yeo-Min
    • Environmental Engineering Research
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    • v.16 no.4
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    • pp.205-212
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    • 2011
  • Reverse osmosis (RO) technology has developed over the past 40 years to control a 44% market share in the world desalting production capacity and an 80% share in the total number of desalination plants installed worldwide. The application of conventional and low-pressure membrane pretreatment processes to seawater RO (SWRO) desalination has undergone accelerated development over the past decade. Reliable pretreatment techniques are required for the successful operation of SWRO processes, since a major issue is membrane fouling associated with particulate matter/colloids, organic/inorganic compounds, and biological growth. While conventional pretreatment processes such as coagulation and granular media filtration have been widely used for SWRO, there has been an increased tendency toward the use of ultrafiltration/microfiltration (UF/MF) instead of conventional treatment techniques. The literature shows that both the conventional and the UF/MF membrane pretreatment processes have different advantages and disadvantages. This review suggests that, depending on the feed water quality conditions, the suitable integration of multiple pretreatment processes may be considered valid since this would utilize the benefits of each separate pretreatment.

Removal of cesium(137Cs) and iodide(127I) by microfiltration·nanofiltration·reverese osmosis membranes (정밀여과·나노여과·역삼투 막에 의한 세슘과 요오드의 제거)

  • Chae, Seon-Ha;Kim, Chung-Hwan
    • Journal of Korean Society of Water and Wastewater
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    • v.28 no.5
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    • pp.549-554
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    • 2014
  • This study was evaluated the applicability of the membrane filtration process (Micro Filtration (MF), nanofiltration membranes (NF), reverse osmosis (RO)) on the major radioactive substances, iodine ($I^-$) and cesium ($Cs^+$) using membranes produced in Korea and domestic raw water. Iodine ($I^-$) or cesium ($Cs^+$) in the microfiltration membrane (MF) process could not be expected removal efficiency by eliminating marginally at the combined state with colloidal and turbidity material. At the domestic raw water (lake water, turbidity 1.2 NTU, DOC 1.3 mg/L) conditions, nanofiltration membrane (NF) and reverse osmosis (RO) showed a high removal rate of about 88 ~ 99% for iodine ($I^-$) and cesium ($Cs^+$) and likely to be an alternative process for the removal of radioactive material.