• Journal of the Korean Society of Industry Convergence
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• v.25 no.5
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• pp.835-842
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• 2022

In this study, the membrane degassing process of the sweep gas - vacuum combination type was proposed for ammonia wastewater treatment. The effect of pH, initial ammonia concentration and scale-up on ammonia degassing performance was investigated. As a result, as the pH and the initial ammonia concentration increased, the degassing permeate flux was improved. On the other hand, the ammonia mass transfer coefficient increased as the initial ammonia reduced, which seems to be due to the driving force of the sweep gas-vacuum combination type membrane degassing system proposed in this study. In addition, 80 mg NH₃/min of the ammonia degassing rate was achieved using a 6×28 inch size module. Better degassing performance is expected if consideration for maintaining vacuum pressure is involved in the scale-up design.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_2
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• pp.1171-1181
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• 2023

In this study, a sweep gas - vacuum hybrid type membrane degassing process was proposed for ammonia wastewater treatment. In addition, the ammonia selective recovery of the hybrid type membrane degassing process was also investigated. As a result, the hybrid type membrane degassing process showed better degassing performance (54.9 mg NH₃/m²min for 360 min) than the sweep gas type (32.3 mg NH₃/m²min) or vacuum type (22 mg NH₃/m²min). Additionally, the hybrid type membrane degassing process showed an excellent ammonia selectivity (103 times compared to Na+ Na⁺, 133 times compared to Ca²⁺). The ammonia selectivity was appeared to be due to the conversion characteristics of ammonium ion / dissolved ammonia depending on pH. The results in this study are expected to be used in the development of ammonia wastewater treatment and ammonia recovery in the future.

• Proceedings of the Membrane Society of Korea Conference
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• 2001.10a
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• pp.113-138
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• 2001

• Fibers and Polymers
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• v.7 no.2
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• pp.186-190
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• 2006

The application of a degassing system to mercerization process was investigated. It was found that the physical properties of cotton fabrics mercerized in the degassed NaOH solution were superior to those mercerized in NaOH solution. The degree of penetration of the degassed water was examined by measuring wicking height. The wicking height in the degassed water without the wetting agent is higher than that of the saturated water with 0.1 % of wetting agent.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.185-186
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• 2003

막을 이용한 분리기술은 다양한 종류의 혼합물에서 원하는 물질을 분리 정제하는 기술로 여기에는 고-액, 액-액, 기-액분리가 모두 포함된다 현재까지 분리공정은 주로 여과, 증류, 추출, 흡착등 방법이 있으나 에너지소비가 많고, 설비투자비가 많이 들며 효율이 낮아 비경제적이라는 문제점을 가지고 있고 이와 같은 문제점을 해결하기 위하여 최근 주목받고 있는 기술이 막을 이용한 분리기술이다. 막을 이용한 분리기술의 장점은 앞서 언급한 바와 같이 에너지소비와 설비비를 최소화하면서도 고효율의 분리효과를 얻을 수 있다는 점에 있다. (중략)

• Proceedings of the Membrane Society of Korea Conference
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• 2003.07a
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• pp.133-135
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• 2003

The removal of dissolved oxygen(DO) from water was studied using a poly(vinyliene fluoride)(PVDF) hollow fiber membrane contactor(HFMC) with the vacuum degassing process(VDP), Asymmetric porous PVDF hollow fiber membranes (HFM) for membrane contactor were prepared by a wet phase inversion method. In spinning of these PVDF hollow fibers, dimethy lacetamide (DMAc), LiCl and pure water were used as a solvent, a pore-forming additive and internal/external coagulant, respectively. The characteristics of the structure(pore size, porosity etc.) of the prepared PVDF HFMs as a function of concentration of pore-forming additive in polymer dope solution were studied. Also, the removal efficiency of DO from water according to flow rates of water, using PVDF HFMC with VDP, was studied. The performance of the asymmetric porous PVDF HFMC and a symmetric porous PP HFMC commercialized were compared. As a result, the asymmetric porous PVDF HFMC showed higher removal efficiency of DO than that of a symmetric porous PP HFMC.

• Membrane Journal
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• v.30 no.5
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• pp.326-332
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• 2020

In this study, polymer-fluorinated silica composite hollow fiber membranes were fabricated and applied to a membrane contactor for the recovery of methane dissolved in the anaerobic effluent. To prepare the composite membranes, porous hollow fiber substrates were fabricated with Ultem^®, a commercial polyetherimide (PEI). Subsequently, fluorinated silica particles were synthesized and coated on the surface via strong covalent bonding. Due to the high porosity, our membrane showed a CH₄ flux of 8.25 × 10^-5 ㎤ (STP)/㎠·s at the liquid velocity of 0.03 m/s which is much higher that that of commercial polypropylene membrane designed for degassing processes. This is attributed to our membrane's high porosity as well as a superior surface hydrophobicity (120~122°) resulted from the coating with fluorinated silica nanoparticles.