• Proceedings of the Membrane Society of Korea Conference
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• 2004.05b
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• pp.144-146
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• 2004

Various polymeric hollow fiber membranes have been prepared and been used widely due to their high surface area per unit volume and high permselectivity. However, the organic materials are only limited to mild operating conditions because of their weak thermal stability and ease of fouling.(omitted)

• Clean Technology
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• v.5 no.2
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• pp.69-78
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• 1999

Separation characteristics of cutting oil-in-water emulsions were studied experimentally by using various kinds of flat-type microfiltration and ultrafiltration membranes. For ultrafiltration membranes the permeation behavior of cutting oil emulsions obeys the film model, whereas a significant deviation from the model was observed for ASYPOR microfiltration membranes. The experimental data obtained for all the membranes showed that the effect of operating pressure on the permeation flux of oil-in-water emulsions is not very significant. At low transmembrane pressures the permeation flux decreased gradually with increasing filtration time, whereas the permeation flux at high transmembrane pressures decreased steeply for early filtration time. However, every flux eventually reached a constant value that depends only on the applied transmembrane pressure. For the hydrophobic polycarbonate microfiltration membrane the permeation flux increased with the filtration time. The critical permeation pressures were also determined from the data obtained from unstirred cell experiments.

• Membrane Journal
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• v.32 no.2
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• pp.100-108
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• 2022

Among various industries, the textile industry uses the largest amount of water for coloring textiles which leads to a large amount of wastewater containing various kinds of dye. There are various methods for the removal of dye such as flocculation, ozone treatment, adsorption, etc. But these processes are not much successful due to the issue of recycling which enhances the cost. Alternatively, the membrane separation process for the treatment of dye in wastewater is already documented as the best available technique. Polymeric membrane and ceramic membrane are two separate groups of separation membranes. Advantages of ceramic membranes include the ease of cleaning, long lifetime, good chemical and thermal resistance, and mechanical stability. Ceramic membranes can be prepared from various sources and natural materials like clay, zeolite, and fly ash are very cheap and easily available. In this review separation of wastewater is classified into mainly three groups: ultrafiltration (UF), microfiltration (MF), and nanofiltration (NF) process.

• Proceedings of the Membrane Society of Korea Conference
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• 2003.05a
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• pp.31-38
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• 2003

A pilot scale biofilter pretreatment-microfiltration system (BF-MF) was operated to investigate the effect of biofilter treatment in fouling reduction of microfiltration. Biofiltration was expected to reduce the membrane fouling by removal of turbidity and metal oxides. The hollow-fiber MF module with a nominal pore size of 0.1$\mu$m and a surface area of 8m$^2$ was submerged in a filtration tank and microfiltration was operated at a constant flux of 0.5 m/d. Biofiltration using polypropylene pellets was performed at a high filtration velocity of 320 m/d. Two experimental setups composed of MF and BF/MF, i.e., without and with biofilter pretreatment, were compared. Throughout the experimental period of 9 months, biofilter pretreatment was effective to reduce the membrane fouling, which was proved by the result of time variations of trans-membrane pressure and backwash conditions. The turbidity removal rate by biofiltration varied between 40% to 80% due to the periodic washing for biofilter contactor and raw water turbidity. In addition to turbidity, metals, especially Mn, Fe and Al were removed effectively with average removal rates of 89.2%, 67.8% and 64.9%, respectively. Further analysis of foulants on the used membranes revealed that turbidity and metal removal by biofiltration was the major effect of biofiltration pretreatment against microfiltration fouling.

• Membrane Journal
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• v.23 no.3
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• pp.211-219
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• 2013

Effect of water back-flushing period (FT) was investigated in hybrid water treatment process of carbon ultrafiltration and polypropylene (PP) beads coated with photocatalyst, and membrane effect was studied by comparing the previous studies with carbon microfiltration or alumina ultrafiltration, microfiltration membranes. FT 6 min was the most effective to control initial membrane fouling and optimal condition because the membrane fouling resistance was low until initial 60 min and the maximum total permeate volume was acquired at this FT. The turbidity treatment efficiency was high beyond 98.6%, and did not depend on FT, which was same with the previous result of carbon or alumina microfiltration. The organic matters treatment efficiency was the highest value of 98.2% at FT 6 min, which was almost same trend with the previous result of alumina microfiltration. Then the organic matters treatment efficiency of carbon microfiltration was the minimum at no back-flushing (NBF) and increased as decreasing FT, but that of alumina ultrafiltration was the maximum at NBF and also increased as decreasing FT. Therefore it means that water back-flushing effect on the organic matters treatment efficiency had a different mechanism depending on pore size in spite of the same material membranes.

• Membrane and Water Treatment
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• v.1 no.3
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• pp.193-206
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• 2010

Organic fouling and biofouling pose a significant challenge to the membrane filtration process. Photocatalysis-membrane hybrid system is a novel idea for reducing these membranes fouling however, when $TiO_2 photocatalyst nanoparticles are used in suspension, catalyst recovery is not only imposes an extra step on the process but also significantly contributes to increased membrane resistance and reduced permeate flux. In this study, $TiO_2$ photocatalyst has been immobilized by coating on the microfiltration (MF) membrane surface to minimize organic and microbial fouling. Nano-sized $TiO_2$ was first synthesized by a sol-gel method. The synthesized $TiO_2$ was coated on a Poly Vinyl Difluoride (PVDF) membrane (MF) surface using spray coating and dip coating techniques to obtain hybrid functional composite membrane. The characteristics of the synthesized photocatalyst and a functional composite membrane were studied using numerous instruments in terms of physical, chemical and electrical properties. In comparison to the clean PVDF membrane, the $TiO_2$ coated MF membrane was found more effective in removing methylene blue (20%) and E-coli (99%).

• 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.

• Environmental Engineering Research
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• v.24 no.3
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• pp.418-426
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• 2019

Current available commercial membranes are not robust and are therefore destroyed if left to dry out or handled roughly. Woven fibre microfiltration (WFMF) membranes have advantages over its competitors with respect to durability, thus, favourable for the developing economies and operation during rough conditions. Evaluation of the effects of aeration and brushing as a flux enhancement strategies for WFMF membrane was the purpose of this study. The WFMF membrane was found to be susceptible to pore plugging by colloidal material and adsorption/attachment by microbiological contaminants. This led to a 50% loss in flux. Aeration as a single flux enhancement strategy proved insufficient to maintain high flux successfully. Therefore combined flux enhancement strategies yielded the best results.

• Proceedings of the Membrane Society of Korea Conference
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• 2003.07a
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• pp.95-97
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• 2003

The main purpose of this work is to investigate the performance of membranes for treatment of dyeing wastewater. The microfiltration (MF) membranes (titania-blended polysulfone & alumina) were prepared. The nanofiltration (NF) and reverse osmosis (RO) membranes were kindly supplied by the Sae-Han. In order to reuse the wastewater for dyeing, the effluents were treated by the high flux RO and the fouling resistant RO (FRM) membranes. Also, the NF membrane was used for water reuse in rinsing.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.325.1-325.1
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• 2007