• Membrane and Water Treatment
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• 제3권4호
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• pp.221-230
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• 2012

This study employed the modified fouling index (MFI) to determine the performance of a two-step recycling system - a membrane filtration integrated laminar flow water storage (LFWS) tank followed by an ion exchange process to reclaim ultrapure water (UPW) from the wastewater generated from semiconductor wafer backgrinding and sawing processes. The first step consisted of the utilization of either ultrafiltration (UF) or nanofiltration (NF) membranes to remove solids in the wastewater where the second step consisted of an ion exchanger to further purify the filtrate. The system was able to produce high purity water in a continuous operating mode. However, higher recycling cost could be incurred due to membrane fouling. The feed wastewater used for this study contained high concentration of fine particles with low organic and ionic contents, hence membrane fouling was mainly attributed to particulate deposition and cake formation. Based on the MFI results, a LFWS tank that was equipped with a turbulence reducer with a pair of auto-valves was developed and found effective in minimizing fouling by discharging concentrated wastewater prior to any membrane filtration. By comparing flux behaviors of the improved system with the conventional system, the former maintained a high flux than the latter at the end of the experiment.

• Membrane and Water Treatment
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• 제8권1호
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• pp.1-18
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• 2017

In this study, reuse of biologically treated wastewater of denim washing and dyeing industry has been evaluated by membrane technologies. After that experiments were carried out at laboratory scale in textile dyeing unit by using obtained permeate water samples on 100% cotton based raw fabric belonging to examined industry. During membrane experiments, two different UF (UC100 and UC030) and two different NF (NP010 and NP030) were evaluated under alternative membrane pressures. In permeate water obtained on selected samples, conductivity at the range of $1860-2205{\mu}S/cm$, hardness at the range of 60 to 80 mg/L, total color at the range of 2.4 to 7.6 m-1 and COD at the range of 25-32 mg/L was determined. The following analyzes were performed for the dyed fabrics: perspiration fastness, rub fastness, wash fastness, color fastness to water, color fastness to artificial light, color measurement through the fabric. According to analysis results, selected permeate water have no negative impact on dyeing quality. The study showed that membrane filtration gave good performance for biologically treated textile wastewater, and NF treatment with UF pre-treatment was suitable option for reuse of the effluents.

• Membrane and Water Treatment
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• 제7권4호
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• pp.277-296
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• 2016

The aim of this research was to investigate the ability of nanofiltration (NF) and ultrafiltration (UF) membranes as a filtration unit for groundwater treatment for drinking water resources. Commercial membranes denoted as TS40, TFC-SR3 and GHSP were used to study the performance based on rejections and fluxes. The investigation has been conducted using natural groundwater obtained from a deep tube well with initial concentration of iron (Fe) and manganese (Mn) at 7.15 mg/L and 0.87 mg/L, respectively. Experimental results showed that NF membranes exhibited higher fluxes than UF membrane with pure water permeability at 4.68, 3.99 and $3.15L.m^{-2}.h^{-1}.bar^{-1}$, respectively. For metal rejection, these membranes have performed higher removal on Fe with TS40, TFC-SR3 and GHSP membranes having more than 82%, 92% and 86% respectively. Whereas, removal on Mn only achieved up to 60%, 80% and 30%, for TS40, TFC-SR3 and GHSP membranes respectively. In order to achieve drinking water standard, the membranes were efficient in removing Fe ion at 1 and 2 bar in contrast with Mn ion at 4 and 5 bar. Higher rejection of Fe and Mn were achieved when pH of feed solution was increased to more than 7 as TFC-SR3 membrane was negatively charged in basic solution. This effect could be attributed to the electrostatic effect interaction between membrane material and rejected ions. In conclusion, this study proved that NF membrane especially the TFC-SR3 membrane successfully treated local groundwater sources for public drinking water supply in line with the WHO standard.

• 상하수도학회지
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• 제24권6호
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• pp.723-734
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• 2010

With a belief of high water quality production and less chemical usage, membrane technology including Microfiltration (MF), Ultrafiltration (UF), and Nanofiltration(NF) is being employed more and more in drinking water treatment process. However, due to higher energy consumption of UF and NF, MF is normally used for drinking water treatment especially in a plant of large scale. In this investigation, performance ofsand filtration and membrane filtration was compared regarding removal of various water quality parameters, such as TOC, DOC, KMnO4 consumption, THMFP, and HAAFP. Two lines of pilot plant have been operated, one of which line is a traditional advanced water treatment process which includes sedimentation, sand filtration, ozonation, and activated carbon, and the other line is an alternative treatment process which includes sedimentation with inclined plate, MF membrane, ozonation, and activated carbon. For the first about 4months of period, MF filtration showed similar or little bit higher performance than sand filtration. However, after about 4month later, sand filtration showed much higher performance in removing all parameters monitored in the investigation. It was found that sand filtration is a better option than MF filtration as far as microbial community is fully activated in sand filter bed.

• Korean Membrane Journal
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• 제2권1호
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• pp.56-59
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• 2000

The surface charge properties of a polymeric NF and a ceramic UF membranes were characterized in terms of zeta potential and acidity. Both the negative zeta potential and acidity values increased as pH increases due to ionizable acidic functional groups. Increased ionic strength reduced the acidity of the negatively-charged membrane surface as anticipated. Through these results, it can be envisioned are used to reject solutes with ionizable functional groups. Fouling of the negatively-charged membrane with natural organic matter (NOM) having a negative charge density was also investigated with respect to the surface charge. The surface charge of the NF membrane increased negatively when greater NOM adsorption onto the membrane surface occured.

• Membrane and Water Treatment
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• 제9권5호
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• pp.373-383
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• 2018

Fouling by solids and microorganisms is the major obstacle limiting the efficient use of membrane wastewater treatment. In our previous study, two stages microalgae/membrane filtration system was proposed to treat anaerobic digested palm oil mill effluent (AnPOME). This two stages microalgae/membrane filtration system had showed great potential for the treatment of AnPOME with high removal of COD, $NH_3-N$, $PO_4{^{3-}}$, TSS, turbidity, and colour. However, fouling behavior of the membrane in this two stages microalgae/membrane filtration system was still unknown. In this study, empirical models that describe permeate flux decline for dead-end filtration (pore blocking - complete, intermediate, and standard; and cake layer formation) presented by Hermia were used to fit the experimental results in identifying the fouling mechanism under different experimental conditions. Both centrifuged and non-centrifuged samples were taken from the medium with 3 days RT intervals, from day 0 to day 12 to study their influence on fouling mechanisms described by Hermia for ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) filtration mode. Besides, a more detailed study on the use of resistance-in-series model for deadend filtration was done to investigate the fouling mechanisms involved in membrane filtration of AnPOME collected after microalgae treatment. The results showed that fouling of UF and NF membrane was mainly caused by cake layer formation and it was also supported by the analysis for resistance-in-series model. Whereas, fouling of RO membrane was dominated by concentration polarization.

• 멤브레인
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• 제33권3호
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• pp.87-93
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• 2023

전기투석(ED)은 이온교환막을 통한 이온의 분리에서 중요한 과정이다. 해수담수화로 발생하는 염수 처리는 환경적으로 큰 문제이며 막분리 기술을 통한 재활용 효율이 높다. 마찬가지로 알칼리는 가죽, 전기도금, 염색, 제련 등과 같은 여러 화학 산업에서 생산된다. 폐기물의 고농도 알칼리는 부식성이 높고 화학적 산소 요구량(COD) 값이 높기 때문에 환경에 방출하기 전에 처리해야 합니다. 칼슘과 마그네슘의 농도는 염수의 거의 두 배이며 주요 환경 오염 물질인 이산화탄소의 흡착에 완벽한 후보입니다. 수산화나트륨은 양극성 막 전기투석 공정으로 쉽게 생산되는 금속 탄산화 공정에 필수적입니다. 역삼투압(RO), 나노여과(NF), 초여과(UF), ED 등 다양한 공정을 통해 회수가 가능하다. 본 검토에서는 알칼리 회수를 위한 이온교환막에 의한 ED 공정에 대해 논의한다.

• 멤브레인
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• 제31권6호
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• pp.384-392
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• 2021

현재 우리 산업의 가속화된 발전으로 인해 다양하고 많은 양의 오염이 만들어지기 시작하고 있다. 특히 폐수의 경우 석유, 금속 및 유기물로 오염되는 강과 바다가 늘고 있으며, 빠른 조치가 필요해 보인다. 이러한 오염에 대응하기 위해 폐수에서 분리막을 이용한 깨끗한 물의 여과가 비용적으로 유리하고 친환경적인 기술로 떠오르고 있다. 재생 자원으로 만들어진 막여과 기법들이 환경오염의 원인 중 하나인 합성고분자 분리막들을 대체하기 위해 많이 사용되고 있다. 박테리아 셀룰로오스(Bacterial Cellulose / BC)는 순수하고 뚜렷한 형태의 셀룰로오스 나노섬유(Cellulose nanofibrils / CNF)이다. CNF에서 제조된 나노페이퍼는 각기 다른 용도로 한외여과막과 나노여과막으로 사용된다. BC의 높은 결정성으로 인해 폐수 처리 막의 필수 기준인 우수한 기계적 성질을 가질 수 있다. 본 리뷰 논문에서는 염료, 오일 및 중금속 등 폐수의 오염물질들을 걸러내기 위해 사용될 수 있는 BC 기반 분리막들에 대해 논의한다.

• 한국막학회:학술대회논문집
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• 한국막학회 2004년도 추계 총회 및 학술발표회
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• pp.129-131
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• 2004

• Membrane and Water Treatment
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• 제3권2호
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• pp.99-111
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• 2012

The performance of ultrafiltration (UF) membranes with molecular weight cut off (MWCO) of 1000 and 3500 Da in clarifying sugar cane juice was investigated, as well as the performance of a nanofiltration (NF) membrane with MWCO of 200 Da and a reverse osmosis (RO) membrane in concentrating sugar cane juice. For both cases the sugar cane juice had been limed and partially clarified. The UF membranes were found to be effective at clarifying the sugar cane juice in terms of purity rise and reduction in turbidity, colour, starch and protein. A purity rise of approximately 6 was achieved by both UF membranes at trans-membrane pressures (TMP) from 15 to 25 bar. However, Brix reduction in the permeate was between 14.5 and 41.85% and 12.11 and 26.52% for 1000 Da and 3500 Da membranes respectively. For the 200 Da and RO membranes the Brix in the concentrate was increased from 7.65 to 12.3 after 3 hours of operation for the 200 Da membrane at a TMP of 10 bar, whilst the Brix in the concentrate was increased from 15.65 to 27.6 after 3 hours of operation for the RO membrane at a TMP of 35 bar. Overall, UF membranes were found to be unsuitable for clarification of sugar cane juice since significant amount of Brix is reduced in the permeate, whilst RO membranes were found to be effective for concentration of sugar cane juice.