• Title/Summary/Keyword: 이온교환막

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Effect of Current Density and pH of Electrolyte on Anion-Exchange Membrane Fouling (전류밀도와 전해질의 pH가 음이온교환막의 막 오염에 미치는 영향)

  • Choi, Jae-Hwan
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.9
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    • pp.965-969
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    • 2005
  • Current density is an important operating parameter in the ion-exchange membrane process. We observed the effects of fouling of a Neosepta AMX anion-exchange membrane(Tokuyama Soda, Japan) in 0.02 M NaCl solution containing 100 mg/L sodium humate. Membrane fouling was analyzed by measuring the change in the electrical resistance in the under- and over-limiting current density regions. The experimental results found that membrane fouling was negligible at under-limiting current densities, but was increased significantly when an over-limiting current was supplied. After the fouling experiments, the current-voltage curves for the fouled membranes were measured. From the curves, we observed increased electric resistance and reduced limiting current density(LCD), caused by the accumulation of humic acid on the membrane surface. Furthermore, membrane fouling increased as the acidity of the electrolyte solution containing humic acid increased. This occurred because the fouling of an anion-exchange membrane is affected more by the physicochemical properties of the humic substance than by the surface charge of the humate.

Performance Study of Membrane Capacitive Deionization Installed with Sulfonated Poly(ether ether ketone) and Poly(vinyl amine)/poly(vinyl alcohol) Membranes (Sulfonated Poly(ether ether ketone) 및 Poly(vinyl amine)/poly(vinyl alcohol) 혼합막이 장착된 막결합형 축전식 탈염공정의 성능 연구)

  • Kim, Ka young;Rhim, Ji Won
    • Membrane Journal
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    • v.26 no.1
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    • pp.62-69
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    • 2016
  • In this study, sulfonated poly(ether ether ketone) (SPEEK) as cation exchange membrane and blended and crosslinked poly(vinyl amine) (PVAm) with poly(vinyl alcohol) (PVA) membrane as anion exchange membrane were used and then the performance experiments of the membrane capacitive deionization (MCDI) installed with both membranes were carried out. The newly prepared anion exchange membrane were characterized through water content, ion exchange capacity and FT-IR. The crosslinking time of 3 h to 5 h indicated that the salt removal was reduced from 81.3, 65.7% to 53.8%. The effect of PVAm contents from 40, 60, to 80% on the salt removal was shown 81.3, 75.2 and 37.7%, respectively. As a result, it was concluded that the crosslinking time and the content of PVAm had an influence on the salt removal efficiency.

The Preparation and Electrochemical Properties of Pore-filled and Polystyrene-based Anion-exchange Membranes Using Poly(ethylene glycol)methyl Ether Methacrylate (Poly(ethylene glycol)methyl Ether Methacrylate를 이용한 세공충전 폴리스티렌계 음이온 교환막의 제조 및 전기화학적 특성)

  • Mun, Hye Jin;Choi, Jae Hak;Hong, Young Taik;Chang, Bong Jun
    • Membrane Journal
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    • v.25 no.6
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    • pp.515-523
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    • 2015
  • While commercial polystyrene-based ion exchange membranes have simple manufacturing processes, they also possess poor durability due to their brittleness. Poly(ethylene glycol)methyl ether methacrylate with hydrophilic side chains of poly(ethylene glycol) was used as a co-monomer to make the membranes have improved flexibility. Hydrophilicity/hydrophobicity of the anion exchange membranes were able to be adjusted by varying the chain lengths of the poly(ethylene glycol). For the preparation of the anion exchange membranes, a porous PE substrate was immersed into monomer solutions and thermally polymerized. The prepared membranes were subsequently reacted with trimethylamine to produce anion exchange functional groups, Quaternary ammonium salts. The prepared pore-filled anion exchange membranes were evaluated in terms of ion exchange capacity, electric resistance, elongation at break and water uptake.

Performance of Membrane Capacitive Deionization Process Using Polyvinylidene Fluoride Heterogeneous Ion Exchange Membranes Part I : Preparation and Characterization of Heterogeneous Ion Exchange Membranes (폴리비닐플루오라이드 불균질 이온교환막을 이용한 막 결합형 축전식탈염공정의 탈염 성능 Part I : 불균질 이온교환막의 제조 및 특성)

  • Park, Cheol Oh;Rhim, Ji Won
    • Membrane Journal
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    • v.27 no.1
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    • pp.84-91
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    • 2017
  • In this study, heterogeneous ion exchange membranes were prepared by mixing cation or anion exchange resins and commercial polyvinylidene fluoride (PVDF) for MCDI process. The mixing ratios of PVDF and ion exchange resins were 1 : 1, 1.4 : 1, 2 : 1, and 3 : 1. We characterized SEM, water content, ion exchange capacity, methanol permeability, and ion conductivity. In the viewpoint of membrane characterization, the blending ratio of 2 : 1 showed the best. For the blending ratio of 2 : 1, heterogeneous cation exchange membrane showed the water content 34%, ion exchange capacity 1.54 meq/g, ion conductivity 0.019 S/cm, and methanol permeability $2.28{\times}10^{-7}{\sim}8.86{\times}10^{-7}cm^2/s$ while In the case of heterogeneous anion exchange membrane, the result showed 37%, 2.18 meq/g, and 0.034 S/cm and $1.46{\times}10^{-7}{\sim}8.66{\times}10^{-7}cm^2/s$.

A Study on Transport Characteristics of Hydrochloric Acid in an Anion Exchange Membrane (음이온 교환막에서 염산의 이동특성 연구)

  • 강문성;오석중;문승현
    • Membrane Journal
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    • v.8 no.3
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    • pp.148-156
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    • 1998
  • Diffusion dialysis is a membrane process driven by concentration difference using ion-exchange membranes and has been employed for many years for the acid recovery from acidic waste generated in steel, metal-refining and dectro-plating industries. Theoretically acid flux increases in propomon to the acid concentration difference. At acid concentrations higher than 3 N HCl, however, the acid flux had not increased linearly with the concentration difference. In this paper the effects of acid concentrations on diffusion dialysis for hydrochloric acid recovery and the acid transport mechanism in an anion exchange membrane were studied by membrane sorption tests and diffusion clialysis cell tests. The experimental results showed that the molecular diffusion was a major transport mechanism in a low acid concentration range and the proton leakage through an anion exchange membrane played an important role at higher acid concentrations. Also osmotic water transport and membrane dehydration retarded the transport of protons and caused the permeate flux to decrease.

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