• Proceedings of the Membrane Society of Korea Conference
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• 1997.04a
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• pp.63-84
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• 1997

산업발전에 따라 발생하는 각종 오염물질에 의한 양질의 물 부족현간을 해결하거나 산업적으로 특정물질을 분리하기 위하여 새로운 분리기술이 개발되고 있으며 앞으로 인류에 대한 가장 절실한 기술로 떠오를 것이다. 이러한 측면에서 분리막은 가장 효율적인 분리기술로 여겨져 지난 30년간 눈부신 발전을 해왔고 최근 국내에서도 소재개발과 함께 이를 응용한 분리막 System개발이 활발히 이루어지고 있다. 분리막에 의한 공정은 상변화가 없는 분리공정이므로 에너지 측면에서 효율적이며 공정자체가 간단하여 점차 보편적인 기술로 자리를 잡아가고 그 기본원료가 부직포, 종공사나 장,단섬유이므로 주로 화섬회사위주로 소재개발이 주로 되고 있다. 본 발표에서는 최근에 국내에서 생산되기 시작한 역삼투막의 제조방법과 이를 이용한 System설계기술에 대하여 총괄적으로 소개하고자 한다.

• Proceedings of the Membrane Society of Korea Conference
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• 1997.06a
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• pp.183-205
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• 1997

산업발전에 따라 발생하는 각종 오염물질에 의한 양질의 물 부족현상을 해결하거나 산업적으로 특정물질을 분리하기 위하여 새로운 분리기술이 개발되고 있으며 이는 앞으로 인류에 대한 가장 절실한 기술로 떠오를 것이다. 이러한 측면에서 분리막은 가장 효율절인 분리기술로 여겨져 지난 30년간 눈부신 발전을 해왔고 최근 국내에서도 소재개발과 함께 이를 응용한 분리막 System개발이 활발히 이루어지고 있다. 분리막에 의한 공정은 상변화가 없는 분리공정이므로 에너지 측면에서 효율적이며 공정자체가 간단하여 점차 보편적인 기술로 자리를 잡아가고 그 기본원료가 부직포, 중공사나 장단섬유이므로 주로 화섬회사 위주로 소재개발이 주로 되고 있다. 본 발표에서는 최근에 국내에서 생산되기 시작한 역삼투막의 제조 방법과 특성 및 개발동향을 총괄적으로 소개하고자 한다.

• Clean Technology
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• v.23 no.1
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• pp.1-14
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• 2017

At high nitrate concentrations, water must be treated to meet regulated concentrations because it results in threat to human health and eutrophication of natural water. However, it is almost impossible to remove nitrate by conventional water treatment methods such as coagulation, filtration and precipitation, due to its high water solubility. Therefore, other technologies including adsorption, ion exchange, reverse osmosis, denitrification, and electrodialysis are required to effectively remove nitrate. Each of these technologies has their own strengths and drawbacks and their feasibility is weighted against factors such as cost, water quality improvement, residuals handling, and pre-treatment requirements. An adsorption technique is the most popular and common process because of its cost effectiveness, ease of operation, and simplicity of design. Surface modifications of adsorbents have been enhanced their adsorption of nitrate. The nitrate-selective membrane process of electrodialysis reversal and reverse osmosis have proven over time and at many locations to be highly effective in removing nitrate contaminating problems in aqueous solutions. Both electrodiaysis and reverse osmosis methods generate highly concentrated wastes and need careful consideration with respect to disposal.

• Korean Chemical Engineering Research
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• v.55 no.6
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• pp.762-766
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• 2017

Energy recovery device (ERD) is used to save energy consumption in seawater reverse osmosis processes. However, small-scale ERDs (<$100m^3/d$) are hardly observed in seawater desalination market. In South Korea, most of seawater desalination plants for drinking water production are small-scaled and have been operated in island areas or on ships. Thus, the effect of ERDs for these small-scale SWRO processes should not be neglected. In this work, the small-scale SWRO processes are designed and analyzed in terms of energy consumption with/without ERD. The realistic efficiencies of high pressure pumps are considered for the energy analyses. The unit cost of electricity depending on the application place (e.g., inland and island areas, on ships) is investigated to calculate the energy cost for unit water production in various SWRO applications classified by plant capacity, application place, and the installation of ERD. As a result, the energy cost can be saved up to $1,640.4KRW/m^3$ when ERD is applied, and the saving effect increases at smaller plants on ships. In conclusion, the development of small-scale ERDs are necessary because small-scale SWRO processes are dominant in Korean seawater desalination market, and the electricity saving effect becomes higher at smaller-scaled system.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.10a
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• pp.29-30
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• 1995

산업폐수는 종종 희석용액 내에 많은 유독성 물질을 함유하고 있다. 산업폐수를 처리하는 분리공정으로 역삼투막과 한외여과와 같은 막분리 기술은 분리 공정이 간단하고 상변화없이 폐수용량을 크게 감소시킬 수 있고 에너지 소모가 작은 장점을 가지고 있어 그 적용이 확산되고 있다. 계면활성제의 흡착성을 이용한 한외여과 막분리는 높은 막투과속도와 계면활성제의 높은 선택성이 결합된 것인데, Sodium Dodecyl Sulfate(SDS)와 같은 계면활성제를 이용하여 폐수로부터 불용성 중금속 이온과 독성의 유기물질을 분리하는 데에 적용할 수 있다. 임계미셀농도(CMC) 이상에서의 농도에서, 60~200 계면활성제 분자들이 거대분자나 미셀을 형성하면서 서로 응집된다. 그러므로 음으로 하전된 미셀과 결합된 금속 음이온은 2,000에서 10,000 범위의 분자량을 가지는데 역삼투막(RO)보다 작은 압력에서 상당히 큰 막투과속도를 가진 한외여과막에 의해 선택적으로 제거될 수 있다 본 연구의 목적은 중공사 한외여과막의 막투과속도에 미치는 인자들의 영향과, 계면활성제의 흡착성을 이용한 중공사 한외여과 막분리계 성능에 미치는 금속의 형태, S/M 몰비등의 효과를 결정하는데 있다.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.4
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• pp.573-579
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• 2011

As rapid advances in technologies continue, seawater reverse osmosis (SWRO) desalination systems are now more energy-efficient than conventional thermal processes. Some SWRO desalination plants can achieve the specific energy consumption (SEC) below 2 kWh/$m^3$. Along with the development of new membranes and high-performance pumps, energy recovery devices (ERD), which recover the hydraulic energy of brine, have been developed to enhance energy efficiency. In this work, we reviewed general aspects of ERD technologies and their market trends. The advantages and disadvantages of various EDR technologies were compared to explore the future directions of ERD development.

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.319-319
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• 1999

• Proceedings of the Membrane Society of Korea Conference
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• 1999.04a
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• pp.65-68
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• 1999

• Journal of Korean Society of Water and Wastewater
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• v.28 no.4
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• pp.391-396
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• 2014

Ultrapure water (UPW) is water containing nothing but water molecule ($H_2O$). The use of UPW is increasing in many industries such as the thermal and nuclear power plants, petrochemical plants, and semiconductor manufacturers. In order to produce UPW, several unit processes such as ion exchange, reverse osmosis (RO), ultraviolet (UV) oxidation should be efficiently arranged. In particular, RO process should remove not only ions but also low molecular weight (LMW) organic matters in UPW production system. But, the LMW organic matter removal data of RO membranes provided by manufacturers does not seem to be reasonable because they tested the removal in high concentration conditions like 1,000 ppm of isopropyl alcohol (IPA, MW=60.1). In this study, bench-scale experiments were carried out using 4-inches RO modules. IPA was used as a model LMW organic matter with low concentration conditions less than 1 ppm as total organic carbon (TOC). As a result, the IPA removal data by manufacturers turned out to be trustable because the effect of feed concentration on the IPA removal was negligble while the IPA removal efficiency became higher at higher permeate flux.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.4
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• pp.489-495
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• 2011

Silt Density Index (SDI) has been used as a fouling index for reverse osmosis (RO) processes for decades. In order to decrease RO fouling, feed water should meet SDI standard, which was used to select a proper pretreatment system for RO processes. However, SDI is supposed to be sensitive only to particles larger than 0.45 ${\mu}m$ in terms of diameters while nanoparticles and dissolved organic matter can be potent foulants for RO processes. Our study started from the suspected performance of SDI as a RO fouling index. SDI data from pilot plants located world wide including South Korea were collected and analyzed. Suspended partcle concentration (i.e., turbidity and particle counts), and dissolved organic matter concentration (i.e., dissolved orgnaic carbon (DOC) concentration) data were also collected and compared to SDI values of same water samples. We found that SDI values were not only affected by suspended particle concentration but also by dissolved organic matter concentration. Therefore SDI can be used as a reasonable fouling index for RO feed water because the main foulants for RO processes are suspended particle and dissolved organic matter.