• Membrane Journal
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• v.4 no.3
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• pp.142-151
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• 1994

Counter-current type reverse osmosis spiral wound module was manufactured for the separation and concentration of salf solution. The ratio of permeate volumetric flow rate vs. brine volumetric flow rate was effective parameter between rejection and degree of cocentration. The reflection coefficient was correspondent to the relation between rejection and degree of cocentration by Spiegler-Kedem model. Counter-current reverse osmosis process had more osmotic pressure drop effect and more degree of concentration than general reverse osmosis process. As a result of computer calculation, the extension of module length than module diameter was more effective for the increase of degree of concentration.

• Journal of Korean Society on Water Environment
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• v.18 no.4
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• pp.387-394
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• 2002

The efficiency variation of UF(tubular)/RO(spiral wound) process using acrylic wastewater treated by photo-catalyst pretreatment and coagulant-filter-neutralization pretreatment processes were discussed wit the variation of appled pressure and temperature. Ultrafiltration tubular module using acrylic wastewater treated by photo-catalyst pretreatment and coagulant-filter-neutralization pretreatment processes was shown that COD and T-N were not highly affected with the variation of appled pressure and temperature. It was shown that removal efficiency of COD and T-N was low. Removal efficiency of TDS and turbidity with ultrafiltration tubular module was better with the acrylic wastewater by photo-catalyst pretreatment than acrylic wastewater by coagulant-filter-neutralization pretreatment. T-N and TDS were shown high removal efficiency in reverse osmosis membrane process.

• Membrane Journal
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• v.10 no.4
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• pp.220-229
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• 2000

Deionized water and wastewater flux were discussed using module set 1-7 composed of ultrafiltration hollow fiber type modules and reverse osmosis spiral wound type modules. The separation characteristics of ultrafiltration and reverse osmosis membranes were discussed with the variation of applied pressure and temperature. Turbidity and SS were removed effectively from ultrafiltration mem¬brane, and removal efficiency of COD, T-N, and TDS using reverse osmosis membrane was very efficient. Permeate flux increased linearly with the increase of applied pressures and temperature. It was shown that ultrafiltration and reverse osmosis membranes were suitable Lo the advanced treatment and reuse of oil refinery process effluent.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.9
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• pp.476-481
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• 2016

Pressure retarded osmosis (PRO) is a quite new technique for power generation using an osmotically driven membrane process. In the PRO process, water permeates through a semipermeable membrane from a low concentration feed solution to a high concentration draw solution due to osmotic pressure. This study carried out to evaluate the performance of the 8 in spiral wound membrane module using reverse osmosis concentrate for a draw solution and reverse osmosis permeate for a feed solution. Three different flowrates of draw and feed solution, such as 2.4 L/min, 5.0 L/min, and 10.0 L/min were used to estimate the power density and water flux under various range of hydraulic pressure differences between 5 bar and 30 bar. In addition, the effects of feed and draw solution concentration, flowrate, and mixing ratio on 8 in spiral wound PRO membrane module performance were investigated in this study. As major results, increases of the draw solution concentration lead to the improvement of power denstiy, and water flux. Also, increase of flowrate resulted in the improvement of power density and water flux. In addition, optimal mixing ratio of draw and feed solution inlet flowrate was found to be 1:1 to attain a maximum power denstiy.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.4
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• pp.303-310
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• 2017

Pressure retarded osmosis(PRO) has attracted much attention as potential technology to reduce the overall energy consumption for reverse osmosis(RO) desalination. The RO/PRO hybrid process is considered as the most logical next step for future desalination. The PRO process aims to harness the osmotic energy difference of two aqueous solutions separated by a semipermeable membrane. By using the concentrated water(RO brine) discharged from existing RO plants, the PRO process can effectively exploit a greater salinity gradient to reduce the energy cost of processing concentrated water. However, in order to use RO brine as the draw solution, PRO membrane must have high water flux and enough mechanical strength to withstand the high operational pressure. This study investigates the development of a thin film composite PRO membrane and spiral wound module for high power density. Also, the influence of membrane backing layer on the overall power density was studied using the characteristic factors of PRO membranes. Finally, the performance test of an 8-inch spiral wound module was carried out under various operating conditions(i.e. hydraulic pressure, flow rate, temperature). As the flow rate and temperature increased under the same hydraulic pressure, the PRO performance increased due to the growth of water permeability coefficient and osmotic pressure. For a high performance PRO system, in order to optimize the operating conditions, it is highly recommended that the flow pressure be minimized while the flow rate is maintained at a high level.

• Membrane Journal
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• v.12 no.3
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• pp.165-170
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• 2002

Membrane process was investigated to recover useful components, such as protein from rice-washing water generated in the production of the washed-rice. The filtration experiments were carried out using not only a dead-end Amicon cell to determine suitable membranes but also a hollow fiber ultrafiltration, spiral wound nanofiltration and reverse osmosis modules for home water purification. Ultrafiltration module(molecular weight cut-off : 10,000 dalton) was not suitable for recovery of useful components or protein in the rice-washing water, but nanofiltration and reverse osmosis modules showed a good performance. in the case of 250% concentration of the rice-washing water contained about 9% protein the proteins in concentrates of nanofiltration and reverse osmosis were 18% and 22%, which were about 2 and 2.4 times higher protein concentrations than those of feed, respectively.

• Applied Chemistry for Engineering
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• v.10 no.4
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• pp.563-567
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• 1999

Reverse osmosis concentration for cephalosproin C was studied using a polyamide composite membrane, FT-30 in spiral wound type with high solute rejection. The experiments were carried out in the aqueous solution of cephalosporin C for water flux, solute rejection and mass transfer coefficient under applied pressure of $4{\sim}20kg/cm^2$, feed concentration of 100~1000 mg/L and feed velocity of 2.8 and 5.6 L/min at room temperature. The effect of operating pressure on the separation of cephalosporin C showed that permeate flux increased with increasing operation pressure. These results are consistent with those predicted by Kedem-Katchalsky model. Solute rejection was nearly 1. The increase of feed concentration caused the reduction of cephalosporin C rejection, which was higher at low concentration than at high concentration, but degree of reduction was small.

• Proceedings of the Membrane Society of Korea Conference
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• 1997.04a
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• pp.87-109
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• 1997

Reverse osmosis(R/O), ultrafiltration(UF) and microfiltration (MF) processes are widely used for water treatment. In the seminar, characteristics of typical membrane modules including tubular, hollow fiber, plate and frame and spiral wound types will be discussed in detail. The design methods based on hydrodynamics for hollow fiber and spiral wound modules will be introduced analytically. Concentration polarization (CP) and membrane fouling mechnism as well as the techniques for CP reduction will be handled. The CP control techniques contain chemically modified membrane surface, pretreatment of feed water, operation of low trans-membrane pressure, chemical or physical cleaning methods and artificial production of various fluid turbulences near the membrane surface, etc. In especially, the recent commercial membrane modules for CP control including module rotation, vibration and Taylor or Dean vortex system will be introduced and discussed in detail.

• Membrane Journal
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• v.11 no.4
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• pp.152-160
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• 2001

The pretreatment for COD removal of acrylic wastewater and separation characteristics of ultrafiltration hollow fiber type module and reverse osmosis spiral wound type module with the variation of applied pressure and temperature were discussed. Thc optimum washing time of membranes was decided with long team operation and the degree of fouling was discussed with operating time. Permeate flux was decreased rapidly at 14 hrs and that of reverse osmosis membrane was indicated similarly. CaO find sand filter for the first step, neutralization process with treated acrylic wastewater as the second step, UF/RO processes were used as final strep. It was shown treat COD and TDS were below allowable discharge value with the result.

• Membrane Journal
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• v.8 no.1
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• pp.29-41
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• 1998

Thin-film composite reverse osmosis membranes of aromatic polyamides were prepared by the interfacial polymerization. Aromatic polyamides as active skin layer were made from the interfacial polymerization of MPD(m-phenylene diamine) in the aqueous and TMC(trimesoyl chloride) in HCFC(1,1-dichloro-1-fluoroethane) organic solvent. The performances of the various reverse osmosis composite membranes prepared by changing processing variables were examined. The performance of membrane manufactured by batch system was varied with organic solvent, monomer concentration, dipping time, heat treatment temperature, acid acceptor, ethanol post treatment, and acid post treatment. Ethanol post treatment was the most dominant factors in increasing permeate amount, while the monomer concentration and dipping time were the main factors in increasing selectivity. The spiral-wound module was produced with the membrane prepared at optimum condition of the continuous process. Comparing the performance of this membrane module made here with that of commercial membrane module, the permeate flux was increased by 33% while the rejection was decreased by 5%.