• Title/Summary/Keyword: Polysulfone

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Study on the elution of biostimulant for in-situ bioremediation of contaminated coastal sediment (오염된 연안저질의 현장생물정화를 위한 미생물활성촉진제의 용출특성 연구)

  • Woo, Jung-Hui;Song, Young-Chae;Senthilkumar, Palaninaicker
    • Journal of Navigation and Port Research
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    • v.38 no.3
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    • pp.239-246
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    • 2014
  • A study on the elution characteristics of biostimulating agents (sulfate and nitrate) from biostimulants which are used for in-situ bioremediation for the coastal sediment contaminated with organic matter was performed. The biostimulating agents were mixed with the coastal sediment, and then massed the mixture into ball. Two kinds of ball type biostimulant were prepared by coating the ball surface with two different polymers, cellulose acetate and polysulfone. A granular type biostimulant (GTB) was also prepared by impregnating a granular activated carbon in the biostimulating agent solution. The image of scanning electron microscopy for the biostimulant coated with cellulose acetate (CAB) showed that the inner side of the coating layer consisted of irregular and bigger size of pores, and the surface layer had tight structure like beehive. For the biostimulant coated with polyfulfone (PSB), the whole coating layer had a fine structure without pore. The elution rate of the biostimulating agents for the CAB was higher than that for the PSB, and the elution rate for the GTB was considerably higher than that for the PSB in distilled water as well as in sea water. The elution rate of the biostimulating agents in turbulent water flow was about 3 times higher than that in standing water, and the elution rate of nitrate was higher than that of sulfate from the stimulating agents.

Simulation on Concentration of CH4 Using Hollow Fiber Membrane Permeator with Countercurrent Flow (향류 흐름 중공사 분리막의 메탄 농축 수치해석)

  • Seo, Yeonhee;Lee, Seungmin;Park, Sungeun;Jung, Woojin;Kim, Jeonghoon;Lee, Yongtaek
    • Membrane Journal
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    • v.24 no.3
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    • pp.223-230
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    • 2014
  • A numerical analysis was performed for concentration of methane from the biogas using a polysulfone hollow fiber membrane permeator. Governing equations were derived for the countercurrent flow and numerically solved by using the Compaq Visual Fortran 6.6 software. When the methane mole fraction of feed was 0.5, the mole fraction of retentate increased from 0.5 to 0.8; the normalized retentate flow rate to the feed flow rate decreased from 1.0 to 0.57 at the given typical operating condition as the feed gas flowed from the inlet to the outlet of the membrane. As the methane mole fraction of feed was changed to 0.9, the methane mole fraction of retentate became 0.93 and the normalized retentate flow rate was changed to 0.91. When the pressure ratio of the permeate to the feed was varied from 0.33 to 0.17, there was a little difference in the methane mole fraction of retentate for the low stage cut of 0.1, whereas there was an significant increment for the high stage cut of 0.3. The retentate methane mole fraction remained relatively high despite the change of a stage cut as the area of the membrane increased from $1.14m^2$ to $2.57m^2$.

Characteristics of Membrane Filtration as a Post Treatment to Anaerobic Digestion (혐기성 소화의 후처리로서 분리막의 여과특성 연구)

  • Choo, Kwang-Ho;Lee, Chung-Hak;Pek, Un-Hwa;Koh, Ui-Chan;Kim, Sang-Won;Koh, Jong-Ho
    • Applied Chemistry for Engineering
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    • v.3 no.4
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    • pp.730-738
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    • 1992
  • Filtration characteristics according to membrane materials were studied In the ultrafiltration of anaerobic digestion broth as a post treatment method. A series of resistances for different membranes were quantitatively assessed on the basis of the resistance-in-series model. Flux behavior observed with the digestion broth was irrelevant to initial water permeabilities of each membrane. The fluoro polymer membrane showed the most significant improvement of flux with increase of cross-flow velocity, which suggests that the cake layer formed on this membrane is more weakly attached to the membrane surface than those on the other membranes. Flux reduction during longtime running was attrib-used to the polarization layer resistance ($R_p$) as well as the fouling layer resistance($R_f$). Continuous increase of $R_p$ may reflect the variation in the characteristics of cake layers, which could result from size, shape, and structure changes due to lysis and growth of biomass. Hydrophilic cellulosic membrane had a much lower fouling tendency than hydrophobic polysulfone membrane. The depressurization method induced a small increase in flux of $5-10L/m^2/h$. During washing and cleaning, filtrability of each membrane was rapidly recovered within 15 minutes until a stationary value was reached.

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Clarification of Apple Vinegar by Ultrafiltration and Flux Charcateristics (한외여과를 이용한 사과식초의 청징화와 투과특성)

  • Kim, Soon-Dong;Chung, Ho-Duck;Choi, Yong-Hee;Youn, Kwang-Sup
    • Applied Biological Chemistry
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    • v.43 no.1
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    • pp.24-28
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    • 2000
  • This study was conducted to evaluate the effect of ultrafiltration (UF) process variables on permeate flux and membrane resistance and to clarify apple vinegar for quality improvement. Apple vinegar was clarified in a laboratory ultrafiltration system with hollow fiber membrane made of polysulfone and MWCO 30,000 and 10,000. The permeate flux increased with the increase of flow rate and the optimum pressure was $1.5\;kgf/cm^2$ in this system. The turbidity of clarified apple vinegar treated UF largely decreased. pH and acidity of treated samples showed the same level as those of untreated apple vinegar. The permeate flux continuously declined while the fouling material accumulated on the membrane as the operation time increased. Resistance decreased with lower pressure, which could be explained by expansion of pore size at lower pressure and minor compaction of the polarized layer at lower pressure.

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Separation of Highly Purified Antimicrobial Lysozyme Using Ultrafiltration and Characteristics of Membrane Fouling (한외여과 공정을 이용한 고순도 향균 Lysozyme 의 분리 및 막 침착 특성)

  • Lee, Eun-Young;Woo, Gun-Jo
    • Korean Journal of Food Science and Technology
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    • v.31 no.2
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    • pp.458-464
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    • 1999
  • The value of lysozyme as a natural food preservative is continuously increased due to its unique antimicrobial activity. To determine the optimum separation concentration among the various hen egg white protein (HEWP) concentrations (0.25, 0.5, 1.0, w/v), protein concentrations, lysozyme concentrations, specific activities (SA), and purification factors of prefiltered solution (PFS) and PM30 permeate solution (PMS) were compared. The purity of lysozyme separated at each step was analyzed and confirmed by gel permeation chromatography and electrophoresis. The fouling deposits on membrane were observed by SEM. The non-enzymatic proteins were removed over 99% by ultrafiltration (UF). The increased feed concentration did not contribute to the increase of SA. SA of PMS was 18 to 31 times higher than that of PFS. The optimum feed concentration was decided as 0.25% based on SA and purification factor. The non-enzymatic region of gel chromatogram was proved to be ovalbumin. The thickness of deposit on the UF membrane was approximately $0.9{\mu}m$ and removed by cleaning with 0.1 N NaOH. Therefore, UF using PM30 membrane was very effective to separate the antimicrobial lysozyme from various HEWPs.

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Preparation and Characterization of Crosslinked Copolymer Membrane Containing Sulfonated Poly(ether sulfone) and p-Phenylene Terephthalamide Segments (Sulfonated Poly(ether sulfone)과 p-Phenylene Terephthalamide 세그먼트를 포함하는 가교 공중합체 멤브레인의 제조 및 특성 연구)

  • Kim, Jung-Min;Hwang, Seung-Sik;Cho, Chang-Gi
    • Polymer(Korea)
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    • v.35 no.2
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    • pp.106-112
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    • 2011
  • Aromatic copolyamides were prepared and their applicability to proton exchange membrane was studied. The copolymers contain two segments; thermally stable and mechanically strong poly (p-phenylene terephthalamide) (PPTA), and easily processable and good film-forming polysulfone. For the copolymers, different ratios of amine-terminated sulfonated ether sulfone monomer, terephthaloyl chloride, and p-phenylene diamine were sequentially reacted. The obtained copolymers were mixed with trimethylolpropane triglycidyl ether (TMPTGE), thermally cured, and converted into proton exchange membranes for fuel cell application. The reactions at each step and the molecular characteristics of precursor copolymers were confirmed by $^1H$ NMR, FTIR, and titration. The performance of the membranes was measured in terms of water uptake and proton conductivity. The water uptake, ion exchange capacity (IEC), and proton conductivity of the membranes increased with the increase of sulfonated ether sulfone segment content. Membrane containing 60 mol% sulfonic acid sulfone segment showed 1.88 meq/g IEC value. Water uptake was limited less than 110 wt% and the highest proton conductivity was up to $7.4{\times}10^{-2}$ S/cm ($25^{\circ}C$, RH=100%).

An Ultrafiltration Study for the Recycling of Synthetic Water-Based Cutting Oil (수용성 합성 절삭유의 재사용을 위한 한외여과 연구)

  • Kim, Jong-Pyo;Kim, Jae-Jin;Ryu, Jong-Hoon
    • Clean Technology
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    • v.8 no.3
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    • pp.119-128
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    • 2002
  • In the present study the membrane filtration characteristics of a commercially available synthetic water-based cutting oil through two kinds of ultrafiltration membranes (HF1-45-CM50 and HF1-43-CM100) with molecular weight cut-offs of 50,000 and 100,000, respectively, have been investigated in detail. Among these membranes, the hydrophilic one (HF1-45-CM50) was found to show a satisfactory result for both the permeate flux and the permeability of oil components, whereas the permeate flux obtained with the hydrophobic membrane (HF1-43-CM100) appears to be significantly low, indicating that synthetic cutting oil was easily wetted on the hydrophobic membrane surface and induced more membrane fouling. The effect of material characteristics of the membrane on the filtration characteristics was found to be much more significant compared with the mean pore size of the membrane. Backflushing by nitrogen gas was applied to reduce the formation of a gel layer and membrane fouling. With the hydrophilic membrane, the backflushing was found to increase the permeate flux, whereas the backflushing resulted in a decrease in flux for the hydrophobic membrane. The flux recovery was observed to be highest when the membranes fouled with waste synthetic cutting oil were immersed into a cleaning solution for more than 72 hours and then backflushed by nitrogen gas.

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Characteristic of the Permeation Flux of Hollow Fiber Membranes by Process Pressures Change (공정압 변화에 따른 중공사막의 투과플럭스 특성)

  • Lee, Yong-Taek;Kim, Nam-Su;Shin, Dong-Ho
    • Membrane Journal
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    • v.17 no.4
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    • pp.318-328
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    • 2007
  • This study was carried out to evaluate the performance of the separate membrane (HF; hollow fiber membrane with polysulfone) process applied with the external membrane types, internal pressure membrane types and external-internal types according to the variations of pressure and membrane pore size in the purification treatment process of the lake water. The maximum permeate flux was average values of 282 LMH and 234 LMH with the pore size of 0.3 and 0.05 ${\mu}m$ respectively in the external pressure membrane process, and 443 LMH and 522 LMH with the pore size of 0.3 and $0.05{\mu}m$ respectively in the internal pressure membrane process. In addition, the maximum permeate flux of the process that was applied with external and internal membrane pressure simultaneously showed the average values of 674 LMH with the pore size of $0.3{\mu}m$, and 648 LMH with the pore size of $0.05{\mu}m$. Therefore, maximum yield per unit area is supposed when the separate membrane that was applied with external and internal pressure simultaneously are used to treat the lake water.

Synthesis, Morphology and Permeation Properties of poly(dimethyl siloxane)-poly(1-vinyl-2-pyrrolidinone) Comb Copolymer (폴리디메틸실록산-폴리비닐피롤리돈 빗살 공중합체 합성, 모폴로지 및 투과성질)

  • Patel, Rajkumar;Park, Jung Tae;Park, Min Su;Kim, Jong Hak
    • Membrane Journal
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    • v.27 no.6
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    • pp.499-505
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    • 2017
  • The increasing number of natural disasters resulting from anthropogenic greenhouse gas emissions has prompted the development of a gas separation membrane. Carbon dioxide ($CO_2$) is the main cause of global warming. Organic polymeric membranes with inherent flexibility are good candidates for use in gas separation membranes and poly(dimethyl siloxane)(PDMS) specifically is a promising material due to its inherently high $CO_2$ diffusivity. In addition, poly(vinyl pyrrolidine)(PVP) is a polymer with high $CO_2$ solubility that could be incorporated into a gas separation membrane. In this study, poly(dimethyl siloxane)-poly(vinyl pyrrolidine)(PDMS-PVP) comb copolymers with different compositions were synthesized under mild conditions via a simple one step free radical polymerization. The copolymerization of PDMS and PVP was characterized by FTIR. The morphology and thermal behavior of the produced polymers were characterized by transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Composite membranes composed of PDMS-PVP on a microporous polysulfone substrate layer were prepared and their $CO_2$ separation properties were subsequently studied. The $CO_2$ permeance and $CO_2/N_2$ selectivity through the PDMS-PVP composite membrane reached 140.6 GPU and 12.0, respectively.

Selective Permeate Transport Characteristics of Iodine ion at Cell Membrane Model of Thyroid which Irradiated by High Energy X-Ray (고에너지 엑스선을 조사한 갑상선의 세포막모델에서 요오드이온의 선택적 투과성 전달 특성)

  • Ko, In-Ho;Yeo, Jin-Dong
    • Journal of the Korean Society of Radiology
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    • v.15 no.2
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    • pp.229-238
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    • 2021
  • The selective permeate transport characteristics of iodine ion at follicle cell membrane model in thyroid which irradiated by high energy x-ray(linac 6 MV) was investigated. The follicle cell membrane model used in this experiment was a polysulfonated copolymerized membrane of poly(4-vinylpyridine-co-acrylonitrile:VP-AN). The difference of membrane thickness [2 mole AN%(w/w)], fixed carrier concentration[VP-AN%(w/w)], OH- concentration were occurred at difference of I- concentration and quantity of thyroid hormone, respectively. The tensile strength in fixed carrier concentration[VP-AN% (w/w): 0-62 %] of irradiated membrane was found to be decreased about 1.2-1.8 times than non-irradiated membrane. The I- selective permeate initial flux with increase of membrane thickness [2mole AN%(w/w)], fixed carrier concentration[VP-AN%(w/ w)], OH- concentration in irradiated membrane were found to be decreased about 2.1-4.5 times, about 2.2-2.5 times, about 2.1-2.67 times than non-irradiated membrane, respectively. As a result, the quantity of thyroid hormone was decreased at irradiated membrane than non-irradiated membrane. The decrease of thyroid hormone was occurred at hypothyroidism and hyperthyroidism, thyroid cancer, and so on. As the thyroid hormone in cell membrane model were abnormal, cell damages were appeared at cell.