• Journal of Environmental Science International
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• v.20 no.10
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• pp.1233-1241
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• 2011

The main objective of this experimental investigation was $CH_4$ recovery from biogas generated in municipal and wastewater treatment plant. The polysulfone hollow fiber membrane was prepared in order to investigate the permeation properties of $CH_4$ and $CO_2$. Permeability of $CO_2$ in Polysulfone membrane was 11-fold higher than of $CH_4$ gas. A membrane pilot plant for upgrading biogas was constructed and operated at a municipal wastewater treatment plant. The raw biogas contained 66 ~ 68 Vol % $CH_4$, the balance being mainly $CO_2$. The effect of the operating pressure of feed and permeate side and feed flowrate on $CH_4$ recovery concentration and efficiency were investigated with double stage membrane pilot plant. The $CH_4$ concentration in the retentate stream was raised in these tests to 93 Vol % $CH_4$.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.459-465
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• 2001

The work was initiated to investigate the electrokinetic properties of a MF membrane using streaming potential measurement when oil emulsion was separated. The original and the surface modified PP membrane were examined by using flux and streaming potentials for the characterization of fouling phenomena of the PP membrane. The membrane surface was modified by a radiation grafting technique. The streaming potentials of the PP membranes were varied the charge distribution modifying by changing the pH, ionic strength, and concentrations the surfactants in oil emulsion. The shiftness to the more positive values of isoelectric point of the PP membrane was significant especially in the presence of surfactants or the surface modification.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.10a
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• pp.14-16
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• 1994

Requirements for the hemodialysis membrane are excellent permeability for water and solute, mechanical strength and blood compatibility. Many synthetic polymer membranes have been invertigated to raise the efficiency of dialysis, however, 85% of the worldwide hemodialysis still uses cellulose membrane. Though the cellulose membrane has both good permeability and mechenical properties, its blood compatibility needs to be improved for hemodialysis. In this paper, 2-(methacryloyloxy)ethyl-2-(trimethyl ammonium) ethyl phosphate(MTP) and Glycidylmethacrylate(GMA) were grafted on the cellulose membranes to make blood compa- tible membranes.

• Membrane Journal
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• v.30 no.4
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• pp.205-212
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• 2020

This short review focuses on fouling by proteins and macromolecules in microfiltration/ultrafiltration. First, an experimental system that enables investigation of how the extent of the adsorption of proteins and macromolecules on membrane surfaces contributes to a decrease in filtrate flux in microfiltration/ultrafiltration is described. Using this system, a causal relationship - not a correlation - indicating that adsorption results in a decrease in filtrate flux could be clearly demonstrated in some cases. Second, a hydration structure at the membrane surface that can suppress adsorption is discussed, inspired by biomaterial research. In their hydrated states, polymers with low-fouling properties have water molecules with a particular structure. Finally, some successful examples of the development of low-fouling membranes via surface modification using low-fouling polymers are discussed.

• Membrane and Water Treatment
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• v.3 no.4
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• pp.231-242
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• 2012

The performance of a nanofiltration membrane for treatment of a low-level radioactive liquid waste was investigated through static and dynamic tests. The liquid waste ("carbonated water") was obtained during conversion of $UF_6$ to $UO_2$. In the static tests membrane samples were immersed in the waste for 24, 48 or 72 h. The transport properties of the samples (hydraulic permeability, permeate flow, selectivity) were evaluated before and after immersion in the waste. In the dynamic tests the waste was permeated in a permeation flow front system under 0.5 MPa, to determine the selectivity of NF membranes to uranium. The surface layer of the membrane was characterized by zeta potential, field emission microscopy, atomic force spectroscopy and infrared spectroscopy. The static test showed that the pore size distribution of the selective layer was altered, but the membrane surface charge was not significantly changed. 99% of uranium was rejected after the dynamic tests.

• Proceedings of the Membrane Society of Korea Conference
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• 1999.07a
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• pp.83-86
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• 1999

The imidization effect of a poly (amic acid) dope solution on membrane formation has been investigated. Poly (amic acid) solution in S-methyl-2-pyrrolidione hs been thermally imidized at $120^{\circ}C$ with different curing time and its degree of imidization was determined by infrared spectroscopy. The solution properties have been studied as a function of concentration and curing time by dynamic light scattering. The quality of a solvent was changed from good to poor with increasing imidization of poly(amic acid).The reduced polymer-solvent interaction diminishes the membrane formation time. The morphology of a membrane was able to be controlled by the characteristics of dope solution.

• Proceedings of the Membrane Society of Korea Conference
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• 2003.07a
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• pp.137-138
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• 2003

The worldwide annual production of polyolefins amounted to 60 million tons in 2000. During the process, 1-2 wt% of the olefin monomers have been emitted and flared into the air, causing the huge energy consumption and severe carbon dioxide emission. Recently, membrane process has been proved to be the most competitive among other separation processes in terms of cost of equipments, energy consumption and safety in this application. The performance of membrane process highly depends on the membrane properties and thus, it is very important to develop good membrane materials and composite membranes. We prepared PMDS dense and composite membranes and studied basic permeation behaviors of a series of olefins(ethylene, propylene, 1 -butylene), nitrogen and hydrogen as model gases.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.47-50
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• 2004

Since emulsion liquid membrane (ELM) was found by Li in the late 1960s$^{[1]}$ , a great amount of work has been conducted on the research and application of ELM$^{[2-8]}$ . Generally, during a process of ELM separation, three types of emulsions will be shown in turn. They are primary emulsion, multiple emulsion, namely ELM, and recovered emulsion respectively. Those three types of emulsions inevitably share some common properties, and at the same time, because those three types of emulsions emerge in different stages of ELM separation, some differences will be observed.(omitted)

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.166-169
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• 2004

Microfiltration membranes were prepared from aromatic polyethersulfone (PES) polymer, using aprotic solvent (N-methyl-2-pyrrolidone, NMP) and non-solvent additive (2-methoxy ethanol, 2-ME) by the phase inversion co-process of the vapor-induced phase inversion (VIPI) and the nonsolvent-induced phase inversion (NIPI). According to the change of the additive amount, the solvent amount and the relative humidity, membrane characterization was studied. The non-solvent additive in casting solution played an important role in membrane morphology. During the vapor-induced phase inversion, the relative humidity led to water sorption on the surface of casting dope at which pore formation was generated. The prepared membranes were characterized by scanning electron microscope observations, measurements of capillary flow porometer and pure water flux (PWP). Also the thermodynamic and kinetic properties of membrane-forming system were studied through coagulation value, light transmittance and viscosity.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.143-150
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• 1996

The membrane fatty acid composition of tumor cell can be modified either in cell by altering the lipid composition of the medium of during growth in animals by changing the dietaty fat composition. These modifications are associated with changes in membrane physical properties and certain cellular functions, including carrier-mediated transport and enzyme contained within the membrane. Such effects influence the transport of nutrients and chemotherapeutic agents in cancer cells .Fatty acid modification also can enhance the sensitivity of the neoplastic cell to chemotherapy. The alteration in plasma membrane composition will be affected through dietary supplementations and the potential value to cancer patients could be a better understanding of the effects of diet on responsiveness of neoplasms to chemotherapy, i.e. cancer patients' chances for a "cure" can be improved by diet changes prior to treatment.