• Membrane Journal
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• v.26 no.5
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• pp.401-406
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• 2016

In this study, we have investigated the removal of the low level radioactive ions of Cs and I in water by the reverse osmosis (RO) process. The two RO modules produced in domestic region and the waste RO module after the cleaning process were selected. Then we compared removal performance of both Cs and I. The experiments are conducted by varying the concentration of feed, the pressure. As a results, it was confirmed that all three modules are higher I decontamination factor than Cs. And particularly, for the cleaned RO module, its decontamination factor of I was 1140. Since the results at low pressure condition were better than that at high pressure conditions, the use of the direct installation of RO modules on the tap water might be possible. In addition, it was confirmed that the waste RO module after cleaning process using EDTA, SBS and NaOH, increased the decontamination performance better than before cleaning, in particular, the recovery ratio after cleaning was 6.3% higher.

• Membrane Journal
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• v.3 no.2
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• pp.41-50
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• 1993

최근 산업의 고도화 및 다변화호 인한 고순도, 고품위의 제품이 요구됨에 따라 분리공정은 대단히 중요한 공정으로 인정되고 있어 화학공업, 식품공업, 약품공업 등의 공업분야뿐만 아니라 의료, 생화학 및 환경분야에 이르기까지 중요한 연구과제가 되고 있다. 분리공정은 열역학적 상평형 원리에 기인한 분리방법과 물질이동 즉, 이동속도 원리에 기인한 분리방법과 물질이도 즉, 이동속도 원리에 기인한 분리방법으로 구별할 수 있는데 이는 혼합물의 동적 성질, 특히 확산성이나 침투속도가 서로 다른 것을 이용한 것이다. 막을 이용한 분리공정은 막의형태, 조작원리 및 적용분야에 다라 정밀여과, 한외여과, 역삼투, 기체분리 및 투과증발 등으로 분류되며 이는 고분자막에 존재하는 Pore의 크기, 막의 균일성, 대칭성 및 막의 하전형태에 따라 구분한다.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.4
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• pp.459-469
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• 2016

Gas hydrate desalination process is based on a liquid to solid (Gas Hydrate, GH) phase change followed by a physical process to separate the GH from the remaining salty water. The GH based desalination process show 60.5-90% of salt rejection, post treatment like reverse osmosis (RO) process is needed to finally meet the product water quality. In this study, the energy consumption of the GH and RO hybrid system was investigated. The energy consumption of the GH process is based on the cooling and heating of seawater and the heat of GH formation reaction while RO energy consumption is calculated using the product of pressure and flow rate of high pressure pumps used in the process. The relation between minimum energy consumption of RO process and RO recovery depending on GH salt rejection, and (2) energy consumption of electric based GH process can be calculated from the simulation. As a result, energy consumption of GH-RO hybrid system and conventional seawater RO process (with/without enregy recovery device) is compared. Since the energy consumption of GH process is too high, other solution used seawater heat and heat exchanger instead of electric energy is suggested.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2015.10a
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• pp.437-438
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• 2015

• Journal of Korean Society of Water and Wastewater
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• v.25 no.2
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• pp.171-176
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• 2011

Organic matters that comprise a tiny part of seawater generally occur over 50% of membrane fouling in Reverse Osmosis Process. This study evaluates Foundation efficiency of reverse osmosis membranes under brackish and seawater conditions and resistance of organic fouling. Moreover, analyzing the membrane surface through roughness, contact angle and zeta potential results in roughness and contact angle are proportional to flux decline rate (FDR), yet FDR has high value when zeta potential is low level. Furthermore, with various membrane fouling of different raw water conditions, the flux tends to improve when pH value is high and raw water which is complex with organic and cation pollutes membrane faster than organic separated raw water condition.

• Membrane Journal
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• v.2 no.1
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• pp.33-48
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• 1992

OSRO process was developed and it was confirmed more effective in ethanol concentrating process comparing to reverse osmosis process. It may be industrialized if more effective membrane for OSRO and reverse osmosis, which indicate the value greater than zero, it was shown that OSRO process was more effective than reverse osmosis for the ethanol concentration process. The decrease of feed concentration and flow rate and the increase of applied pressure made more effective operating conditions in OSRO process to concentrate ethanol. From the numerical esults for the multi-plates, theoretical DC values of reverse osmosis and OSRO process was increased as the umber of stages increased. DC values were increased with the increase of applied pressure in same number of stages. The theoretical values of DC by numerical calculation were corresponded to the experimental values within 15% tolerance. DC value was increased proportional to applied pressure and osmotic sink solution flow rate but it was decreased proportional to feed concentration and flow rate. The numerical calculation over the wide ranges inclading experimental condition was proposed in this study.

• 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%.

• Korean Chemical Engineering Research
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• v.56 no.5
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• pp.679-686
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• 2018

Reverse osmosis (RO) concentration of sodium chloride, sodium acetate, and sodium citrate solutions has been performed by polyamide RO membrane. Concentration polarization phenomena was also studied by changing pressure, solute kinds, and initial solution concentration. Pressure effect on permeation flux was that the increase of flux was accompanied by the increase of pressure. Flux increase was observed by the decrease of initial solution concentration. Surface concentration on the RO membrane increases and so flux declines due to the concentration polarization. In the later phase of concentration, concentration polarization effect was decreased by the back diffusion of solute from the polariztion layer. In case of sodium citrate, its large ion size and charge density resulted in the discrepancy between theory and experimental data of concentration polarization. It may be due to electric repulsion on the membrane surface.

• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.17-24
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• 2000

Reverse osmosis (RO) system was applied to improve wine quality. General wine (GEN) and wines containing different sugar levels $24^{\circ}Brix$ (RO-24) and $24^{\circ}Brix$ (RO-28) by removing pure water using RO system without sugar addition on brewing method. And they were compared by wine aroma analysis. The preparing method of analysis was LLCE (liquid-liquid continuous extraction). And volatile aroma compounds of different wines were prepared for raw, and diluted materials in same proportion. The wine aromas were described by trained twelve panelists for QDA (quantitative descriptive analysis) and showed for FD (flavor dilution)-chromatogram. Consequently, overall acceptability of RO-28 showed better than that of other treatments. Aromas of RO-28 also were represented the high contents of positive aroma compounds such as ethanol and ethyl acetate, which were identified by GC-O and GC-MS.

• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.272-273
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• 2005

분리막 기술은 탁월한 처리효율뿐 아니라 안정적으로 용수를 생산할 수 있는 장점이 있기 때문에 용수의 생산을 전통적인 수처리 (Conventional water treatment) 공정에서 역삼투 공정(Reverse Osmosis) 및 나노여과 (Nanofiltration)와 같은 분리막 기술을 활용하는 공정으로 변환하는 추세에 있다. 그러나 분리막 공정은 항상 막오염 현상이 문제점으로 지목되고 있기 때문에 막오염 제어 기술의 확보가 시급한 실정이다. 따라서 본 연구에서는 화학물질의 사용에 따른 2차 환경오염 문제가 발생하는 화학약품이나 물리적인 세정이 아닌 고전압 임펄스 (HVI, High Voltage Impulse) 장치를 이용하여 막오염의 근본적인 문제를 제어하려 한다.