• 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.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.12
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• pp.2205-2213
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• 2000

To investigate removal efficiency of dissolved matter by NF and RO, a pilot plant was operated for six months using groundwater treated by UF membrane. After the pilot plant operation, we performed autopsy test to identify characteristics of foulant attached on the membrane surface applying the used NF and RO in the pilot plant test. In autopsy test, we measured permeate flux and recovery rate of flux by chemical cleaning in each membrane. We also analyzed chemical cleaning disposal to examine component of foulant. Permeate flux of NF and RO1 showed rapid decline after 100 days of operation. Especially, reduction of specific flux in RO1 was more serious than in NF. Specific flux of RO2 with a low recovery rate resulted in gradual flux decline. Removal efficiencies of dissolved inorganic matters as a conductivity were 76.3%, 88.2% and 95.3% respectively for NF, RO1 and RO2, and RO2 presented the highest removal efficiency. And those of dissolved organic matters as TOC were about 80% for both NF and RO. The specific flux of membranes declined gradually from the feed water inlet to outlet of the membrane module and it showed that membrane fouling increased along the feed flow direction. Namely, concentration of pollutants became higher and volume of feed water was less as the feed flow approached to the outlet. It seemed that major foul ants were Ca consolidated into inorganic material and Si consolidated into organic material on the membrane surface. Fe was a great contribution to irreversible fouling. The SEM results indicated that the organic matter was attached to the first layer, closer to the membrane, and then inorganic matter with tetragonal shape layered over them. We could not observe biofouling because microorganism, which was cause of biofouling, was almost pretreated in UF membrane.

• Journal of Environmental Impact Assessment
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• v.21 no.5
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• pp.707-713
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• 2012

There are a lot of parameters affecting microbial acclimation/cultivation characteristics such as dynamic conditions, F/M ratio and substrate affinity. From the process control point of view, the effect of high salinity on the removal efficiencies of BOD and SS have been documented by few researchers. In this research, lab-scale CAS(Conventional Activated Sludge) process and modified $A_2O$(Anaerobic/Anoxic/Oxic) process were operated and monitored to evaluate the characteristics of microbial acclimation and cultivation under high salinity wastewater during the period of three weeks. As a result of acute microbial activity test(6hr) at various $Cl^-$ concentration, the appropriate $Cl^-$ concentration for microbial growth and acclimation ranged under 3,100 mg/l. As a result of acclimation/cultivation test, the trend of COD removal efficiency reduced gradually as time elapsed. It is considered that $NH_4$-N removal phenomenon of the conventional pollutants removal mechanisms gave little effect to the microbial acclimation/cultivation under high salinity wastewater.

• Proceedings of the Membrane Society of Korea Conference
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• 1993.10a
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• pp.65-67
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• 1993

도금공업은 공업기반기술의 하나로서 기계 및 소재산업의 최종 마무리 공정으로 중요시 되고 있으나 운전중 기술의 특성에 의하여 중금속이 함유된 도금폐수를 방출하게 되어 인체 및 생태계에 매우 유해한 산업중의 하나이다. 기존의 도금폐수처리 방븝으로 침전 응집법이 있으나 이는 사용되는 약품의 양이 많고, 슬러지를 배출하여 2차 공해를 유발하므로 완전한 처리 방법이라 할 수 없다. 본 연구에서는 이러한 국내 도금폐수의 현황을 조사한바 도금폐수중 배출양이 가장 많은 아연계폐수를 대상으로 RO Membrane를 사용하여 실험하였다. RO Membrane으로 실험하였을때 아연이온은 Retentate로 분리 농축되고 Permeate는 재생수로 순환 사용할 수 있는 도금폐수의 무배출 처리공정(Zero-Discharge System) 개발을 존 연구의 목적으로 하였다.

• Membrane Journal
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• v.32 no.4
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• pp.209-217
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• 2022

Ion exchange membrane (IEM) is an important class of membrane applied in batteries, fuel cells, chloride-alkali processes, etc to separate various mono and multivalent ions. The membrane process is based on the electrically driven force, green separation method, which is an emerging area in desalination of seawater and water treatment. Electrodialysis (ED) is a technique in which cations and anions move selectively along the IEM. Anion exchange membrane (AEM) is one of the important components of the ED process which is critical to enhancing the process efficiency. The introduction of cross-linking in the IEM improves the ion-selective separation performance due to the reduction of free volume. During the desalination of seawater by reverse osmosis (RO) process, there is a lot of dissolved salt present in the concentrate of RO. So, the ED process consisting of a monovalent cation-selective membrane reduces fouling and improves membrane flux. This review is divided into three sections such as electrodialysis (ED), anion exchange membrane (AEM), and cation exchange membrane (CEM).

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.361-364
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• 2004

EPA and DHA extracted from methyl esterified squid oil were purified by silver exchanged resin, silver nitrate-impregnated silica gel, silver exchanged zeolite, and silica gel column chromatography, among which column chromatography using mixture of silver exchanged resin and silica gel (10% by weight) showed the best result. By this simple purification method, EPA and DHA were concentrated from 12.5 to 27.9% (yield, 86,0%) and from 21.7 to 49.5% (yield, 87.3%), respectively. Silver exchanged resin had additional advantages of outstanding reusability and simple recovery of silver.

• Membrane Journal
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• v.19 no.4
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• pp.277-284
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• 2009

In order to select the most suitable membrane to the concentration of vanadium and silica in groundwater, two different commercial NF membrane modules (NE2540-90 and NF90-2540) and three different commercial RO membrane modules (BW30-2540, RE2540-TE, and XLE-2540) were tested. The membrane characteristics test results showed that NE2540-90 module was the most efficient because of higher permeate flux and similar rejection coefficient. Using NE2540-90 module at the transmembrane pressure of $8\;kgf/cm^2$, it was found that the rejection coefficients of vanadium, silica, aluminium, chromium, iron, boron, strontium, and barium were 98.2%, 99.0%, 92.0%, 83.6%, 96.0%, 45.1%, 98.6%, and 69.5%, respectively. It was possible that vanadium and silica contents of groundwater were concentrated into $148.9\;{\mu}g/L$ and 85.8 mg/L respectively by six-stages NF process at the recovery ratio of 15%. The waters produced by NF, which are enriched in vanadium and silica content, are expected to be commercialized the various functional mineral waters.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.10a
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• pp.140-142
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• 1998

돈사에서 발생하는 폐수는 주로 돈뇨와 음용수의 누수 및 세척수 등으로 구성되어 있는데, 생물학적인 축산폐수처리법과 퇴비화법 등으로 처리를 하고 있다. 그러나 일반적인 돈사폐수에는 분의 함량이 많아 부유물질의 양이 많고 유기물 등 오염성분의 농도가 높은 특성을 가지고 있어서 기존의 생물학적 축산폐수 처리법으로는 과부하 운전으로 인한 어려움이 있고, 퇴비화법으로는 수분조절제의 소요량이 많은 문제점을 가지고 있다. 대부분의 현지 양돈농가에서는 돈뇨 등 폐수처리의 어려움으로 인하여 분뇨 분리 시설이 있어도 분뇨를 혼합한 슬러리 형태로 퇴비화하고 있다. 따라서 퇴비화 공정에서 수분조절제로 쓰이는 톱밥의 소요량이 돈분만 퇴비화할 때보다 훨씬 많고 기존의 퇴비화 시설도 과부화 상태로 운전하고 있는 실정이다.

• Membrane Journal
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• v.8 no.2
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• pp.77-85
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• 1998

To treat effectively EDIR (electrodeposition ion removal) wastewater in terms of CO$_{Mn}$ 1,500~2,000 ppm generated from aluminum painting process, a RO (reverse osmosis) process was designed and installed to recover and reuse the concentrated solvent sent back to the electrocodeposition tank while the permeate reused as rinse water. A RO system in which three polyamide-spiral wound modules ($102\Phi \times 1,016L$ mm) connnected in series had been running to treat 20 m$^3$ in waste volume in 3 days batch operation at the condition of system recovery of 30 %, applied pressure 11.5 $kg_f/cm^2$ and room temperature. During 42 hours continuous operation leading to 5-fold decrease in waste volume, nearly constant permeation flux of 390 l/m$^2$-hr was maintained and the permeate with average CO$_{Mn}$, 300 ppm was obtained which could be used for washing the remaining paint solution in ion-exchange tower instead of demineralized water. Also COD$_{Mn}$ rejection as a function of running time was observed to be in the range of 78~87 % and the observed solvent rejections for ethyl cellusolve, buthyl cellusolve and n-butanol were 79 %, 87 % and 70 %, respectively.

• Membrane Journal
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• v.12 no.3
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• pp.182-191
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• 2002

Polyamide reverse osmosis (RO) membrane with thin film composite structure was commercialized for seawater desalination process. Recently, it has been reported that some RO processes for high pressure and recovery leads to reducing in energy cost and pretreatment scale compared with earlier process. The development of energy recovery, pumping device and RO elements with high pressure and rejection made high pressure and recovery process possible. In this study, permeation properties of commercialized seawater RO membrane were investigated under the condition of high pressure and recovery. In the RO sheet membrane test 3.5% NaCl of synthetic seawater was used. The synthetic seawater contained only sodium chloride. In the RO module test, natural seawater was used at Happo Bay, Masan city. As the results, RO membrane with high durability of pressure was better than that with high rejection of seawater for high pressure and recovery process. Seawater rejection of high concentrate tends to be improved by high pressure operation.