• Title/Summary/Keyword: NF membrane

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MODIFIED COMPOSITE MEMBRANES FOR NANOFINTRATION

  • Jegal, Jong-Geon;Oh, Nam-Wun;Park, Duk-Soon;Lee, Kew-Ho
    • Proceedings of the Membrane Society of Korea Conference
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    • 1999.07a
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    • pp.35-38
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    • 1999
  • Nanofiltration (NF) composite membranes based of poly (vinyl alcohol) (PVA) and sodium alginate (SA) were prepared by coating PVA/SA (95/5 in wt %) mixture solutions on the microporous polysulfone (PS) supports, followed by the crosslinking with glutaraldehyed. The composite membranes prepared were characterized with a scanning electron microscopy (SEM), a fourier transform infrared spectroscopy(FTIR), an elecrtokinetic analyzer (EKA) and permeation tests.

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Prediction of Membrane Fouling Index by Using Happel Cell Model (Happel Cell 모델을 이용한 막오염 지수 예측)

  • Park, Chanhyuk;Kim, Hana;Hong, Seungkwan
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.5
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    • pp.632-638
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    • 2005
  • Membrane fouling index such as Silt Density Index (SDI) and Modified Fouling Index (MFI) is an important parameter in design of the integrated RO/NF membrane processes for drinking water treatment. In this study, the effect of particle, membrane and feed water characteristics on membrane fouling index were investigated systematically. Higher fouling index values were observed when filtering suspensions with smaller particle size and higher feed particle concentration. Larger membrane resistance due to smaller pore size resulted in an increased membrane fouling index. The variations of feed water hardness and TDS concentrations did not show any impact on fouling index, suggesting that there were no significant colloidal interactions among particles and thus the porosity of particle cake layer accumulated on the membrane surface could be assumed to be 0.36 according to random packing density. Based on the experimental observations, fundamental membrane fouling index model was developed using Happel Cell. The effect of primary model parameters including particle size ($a_p$), particle concentration ($C_o$), membrane resistance ($R_m$), were accurately assessed without any fitting parameters, and the prediction of membrane fouling index such as MFI exhibited very good agreement with the experimental results.

The Effect of Homnis Placenta Herbal Acupuncture on Reducing Expression of LPS-induced Arthritis Model as an Anti-inflammatory Agent (자하차약침(紫何車藥針)의 항염증능(亢炎症能)이 LPS 유발 관절염(關節炎) 치료(治療)에 미치는 영향(影響))

  • Park, Ki-Bum;Baek, Seung-Tae;Lee, Seung-Deok;Kim, Kyung-Ho;Kim, Kap-Sung
    • Journal of Acupuncture Research
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    • v.23 no.6
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    • pp.103-115
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    • 2006
  • Objectives : Rheumatoid arthritis(RA) is a systemic & a chronic inflammatory autoimmune disease . A chronic , locally destructive inflammmatory reaction in human is examplified by the synovitis present in some connective tissue disorder. The presence of a number of cytokines, $TNF-{\alpha}$, iNOS & expression of nitric oxide, NF-kB p65 activation implies an important role of cellular immune response in RA inflammatory reaction. This study was designed to evaluate on the effects of the Homnis Placenta herbal acupuncture on EX-LE201 & ST 35 reducing expression of LPS-induced arthritis model in mice. Materials and Methods : Homnis Placenta herbal acupuncture was inserted into 10 rats induced rheumatoid arthritis. The acupunctures were injected into the EX-LE201 and ST35 points. Such indexes were measured the inhibition of inducible nitric oxide synthase(iNOS) expression, nitric oxide(NO) production in vitro experiment and Tumor Necrosis $Factor-{\alpha}(TNF-{\alpha})$ & Nuclear Factor kappa $B(NF-{\kappa}B)$ p65 activation, synovial hyperplasia, angiogenesis and fibrosis in synovial membrane of knee joint of mice in vivo experiment. Results : 1.Homnis Placenta Herbal acupuncture inhibited iNOS mRNA and NO in RAW 264.7 cell of LPS-induced rheumatoid arthritis in a dose dependent manner. 2.Homnis Placenta Herbal acupuncture also showed significant inhibition of $TNF-{\alpha}$ & $NF-{\kappa}B$ p65, activation, synovial hyperplasia, angiogenesis and fibrosis in synovial membrane of knee joint of mice. Conclusion : These results suggest that Homnis Placenta Herbal acupuncture has an therapeutic effects on LPS induced-rheumatoid arthritis by inhibiting $TNF-{\alpha}$ activation.

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Prevention of membrane fouling by roughing filter for the stand-alone MD process (해수담수화 막 증류 공정에서 유입수 전처리 적용에 따른 막 오염 평가)

  • Yun, Taekgeun;Jeong, Seongpil;Kim, Hyewon;Hong, Seungkwan;Lee, Seockheon
    • Journal of Korean Society of Water and Wastewater
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    • v.32 no.4
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    • pp.301-307
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    • 2018
  • Membrane distillation (MD) is a thermally driven desalination process with a hydrophobic membrane. MD process has been known to have a lower fouling potential compared to other pressure-based membrane desalination process (NF, RO). However, membrane fouling also occurs in MD process. In this study, the membrane fouling was observed in MD process according to the pre-treatment processes. The filtration and precipitation processes were applied as the pre-treatment to prevent the membrane fouling. The pore sizes of roughing filters were 0.4, 5, 10, 30, and $60{\mu}m$. The concentration of the coagulant was 1.2 mg/L as $FeCl_3$. The membrane fouling on MD membrane was successfully removed with both pre-treatment processes.

Preparation and Characteristics of Fouling Resistant Nanofiltration Membranes (내오염성 나노여과막의 제조 및 특성)

  • Kim, No-Won
    • Membrane Journal
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    • v.17 no.1
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    • pp.44-53
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    • 2007
  • The primary objective of this study is to increase the extent of water flux and fouling resistance of nano-filtration or reverse osmosis membranes. This study was performed to investigate the effect of surface characteristics of silane coated membranes on modified fouling index. Commercial polyamide composite RO membrane (RE1812-LP) and NF membrane (ESNA4040-LF) were treated with silane coupling agents in ethanol at five different concentrations. The silane coupling reagent, aminopropylmethoxydiethoxysilane, contains one aminoalkyl and three alkoxy groups. The hydrophilic effect of aminoalkyl group of APMDES on the permeability and fouling resistance of the modified membrane was examined. The surfaces of the modified membranes were characterized by FE-SEM, contact angle analyzer, and zeta potentiometer in order to confirm successful sol-gel methods. The modified NF membranes showed significantly enhanced water flux and fouling resistance without a decrease in salt rejection in divalent ionic feed solution.

Treatment of natural rubber wastewater by membrane technologies for water reuse

  • Jiang, Shi-Kuan;Zhang, Gui-Mei;Yan, Li;Wu, Ying
    • Membrane and Water Treatment
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    • v.9 no.1
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    • pp.17-21
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    • 2018
  • A series of laboratory scale experiments were performed to investigate the feasibility of membrane separation technology for natural rubber (NR) wastewater treatment and reuse. Three types of spiral wound membranes were employed in the cross-flow experiments. The NR wastewater pretreated by sand filtration and cartridge filtration was forced to pass through the ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membranes successively. The UF retentate, which containing abundant proteins, can be used to produce fertilizer, while the NF retentate is rich in quebrachitol and can be used to extract quebrachitol. The permeate produced by the RO module was reused in the NR processing. Furthermore, about 0.1wt% quebrachitol was extracted from the NR wastewater. Besides, the effluent quality treated by the membrane processes was much better than that of the biological treatment. Especially for total dissolved solids (TDS) and total phosphorus (T-P), the removal efficiency improved 53.11% and 49.83% respectively. In addition, the removal efficiencies of biological oxygen demand (BOD) and chemical oxygen demand (COD) exceeded 99%. The total nitrogen (T-N) and ammonia nitrogen (NH4-N) had approximately similar removal efficiency (93%). It was also found that there was a significant decrease in the T-P concentration in the effluent, the T-P was reduced from 200 mg/L to 0.34 mg/L. Generally, it was considered to be a challenging problem to solve for the biological processes. In brief, highly resource utilization and zero discharge was obtained by membrane separation system in the NR wastewater treatment.

Membrane Technology for Water Treatment in Korea

  • Yoo, Je-Kang;Lee, Kyu-hyun
    • Proceedings of the Membrane Society of Korea Conference
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    • 1995.10a
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    • pp.94-100
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    • 1995
  • In recent years it has become necessary to design water management system to minimize water consumption as well as satisfy more stringent environmental requirements. This is mainly due to the seasonal water shortage and environmental problems on water pollution that have taken place at many industrialized regions in Korea. Accordingly, membrane technology in Korea is finding increasing application in the water industry because it has been found to be effective and economic treatment method compared with conventional technology. The membrane processes with the greatest potential for water and wastewater treatment are microfiltration(MF), ultrafiltration(UF), nanofiltration(NF) and reverse osmosis (RO), which utilize pressure differentials.

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Preparation and Characterization of PVA/SA Blend Nanofiltration membranes

  • Llee, Kew-Ho
    • Korean Membrane Journal
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    • v.1 no.1
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    • pp.86-92
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    • 1999
  • The nanofiltration (NF) membranes based on poly(vinyl alcohol) (PVA) and sodium alginate (SA) were prespared. Homogeneous PVA/SA blend membranes were prepared by casting a PVA/SA (95/5 in wi%) mixture solution on an acryl plate followed by drying at a room temperature and by cros-slinking with glutaraldehyde (GA) for 20 minutes PVA/SA blend composite membranes were also prepared by coating a PVA/SA (95/5 in wi%) mixture solution on microporous polysulfone(PSF) supports. The PVA/SA active layer of the composite membrane was crosslinked at room temperature by using an membranes were characterized with a scanning electron microscopy (SEM) a fourier transform infrared spectroscopy (FTIR) and permeation tests. The permeation properties of the composite membrane were as follows: 1.3{{{{ {m }^{2 } }}}}/{{{{ {m }^{2 } }}}}day of flux and >95% of rejection at 200 psi for a 1000 ppm PEG600 solution.

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Membrane Roles in Potable Water Treatment (먹는물에서 분리막의 역할)

  • Maeda, Yasushi
    • Proceedings of the Membrane Society of Korea Conference
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    • 1996.09a
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    • pp.121-145
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    • 1996
  • Due to more stringent regulations in drinking water, membrane separation has been playing an increasingly important role. Seawater desalination by reverse osmosis is a typical example and has been used world-wide. Although the existing technology based on coagulation and media filtration is well established and reliable technology, with the advance of industrial and agricultural activities it is difficult for this technology to remove contaminants such as nitrate and synthetic organic chemicals. To meet the drinking water standards and produce higher quality water, several membrane filtration research programs have been initiated which include Japanese MAC21 and New MAC21 projects. In this paper, potable water application of reverse osmosis (RO) and nanofiltration(NF) and their case histories will be explained in more detail.

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