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정밀여과(MF)막 미생물 제거율 모니터링을 위한 막 완전성시험
Hong, Seungkwan,Miller, Frank,Taylor, James 대한상하수도학회 2004 상하수도학회지 Vol.18 No.6
The pilot study was conducted to (i) investigate the ability of various membrane integrity monitoring methods to detect changes in membrane integrity during operation, and (ii) determine the impact of membrane damage on microbial removal by microfiltration. Two variations of air pressure hold tests were investigated for direct integrity monitoring: pressure decay (PD) and diffusive air flow (DAF) tests which are most commonly used integrity tests for microfiltration (MF) membranes. Both PD and DAF tests were sensitive enough to detect one damaged fiber out of 66,000 under field operaing conditions. Indirect integrity monitoring such as turbidity and particle counting, however, responded poorly to defects in membrane systems. Microbial challenge study was performed using both new and deliberately damaged membranes, as well as varying the state of fouling of the membrane. This study demonstrated that MF membrane with nominal pore size $0.2{\mu}m$ was capable of removing various pathogens including coliform, spore, and cryptosporidium, at the level required by drinking water regulations, even when high operating pressures were applied. A sharp decrease in average log reduction value (LRV) was observed when one fiber was damaged, emphasizing the importance of membrane integrity in control of microbial contamination.
NH<sub>2</sub>Cl 사용으로 인한 RO 막의 성능 향상
Hong, Seungkwan,Reiss, Robert,Taylor, James S.,Beverly, Sharon 대한상하수도학회 2005 상하수도학회지 Vol.19 No.3
The 15 month pilot study was performed to investigate the effect of pretreatment by monochloramine ($NH_2Cl$) on the performance of RO membranes made of cellulose acetate (CA) and polyamide (PA). Both RO membranes experienced severe biological fouling without any pretreatment during the treatment of highly organic surface water in Florida, USA. Feed monochloramination at 5 mg/L significantly minimized productivity loss by effective control of biofouling. The CA membrane did not show any structural damages by monochloramine, while the PA membrane suffered from a gradual loss of membrane integrity by chlorine oxidation, which was characterized as an increase in productivity and a decrease in selectivity. The degradation of PA membrane increased with increasing monochloramine dose.
Measurements of assimilable organic carbon (AOC) in high saline conditions using P17
Mun, Eunjeong,Lee, Sangyoup,Kim, Inhyuk,Kwon, Boksoon,Park, Heedueng,Hong, Seungkwan IWA Publishing 2013 WATER SCIENCE AND TECHNOLOGY -WATER SUPPLY- Vol.13 No.2
sion='1.0' encoding='utf-8'?><!DOCTYPE article PUBLIC '-//NLM//DTD Journal Publishing DTD v2.3 20070202//EN' 'journalpublishing.dtd'><article article-type='research-article' xmlns:xlink='http://www.w3.org/1999/xlink'><front><journal-meta><journal-id journal-id-type='pmc'>ws</journal-id><journal-id journal-id-type='pubmed'>WS</journal-id><journal-id journal-id-type='publisher'>Water Science & Technology: Water Supply</journal-id><issn pub-type='ppub'>1606-9749</issn><publisher><publisher-name>IWA Publishing</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type='doi'>10.2166/ws.2013.019</article-id><article-id pub-id-type='other'>jWSTWS.v13.i2.pg265</article-id><article-categories><subj-group><subject>Research Article</subject></subj-group></article-categories><title-group><article-title>Measurements of assimilable organic carbon (AOC) in high saline conditions using P17</article-title></title-group><contrib-group><contrib contrib-type='author' rid='aff1'><name><surname>Mun</surname><given-names>Eunjeong</given-names></name><xref ref-type='aff' rid='aff1'></xref></contrib><contrib contrib-type='author' rid='aff1'><name><surname>Lee</surname><given-names>Sangyoup</given-names></name><xref ref-type='aff' rid='aff1'></xref></contrib><contrib contrib-type='author' rid='aff1'><name><surname>Kim</surname><given-names>Inhyuk</given-names></name><xref ref-type='aff' rid='aff1'></xref></contrib><contrib contrib-type='author' rid='aff2'><name><surname>Kwon</surname><given-names>Boksoon</given-names></name><xref ref-type='aff' rid='aff2'></xref></contrib><contrib contrib-type='author' rid='aff1'><name><surname>Park</surname><given-names>Heedueng</given-names></name><xref ref-type='aff' rid='aff1'></xref></contrib><contrib contrib-type='author' rid='aff1'><name><surname>Hong</surname><given-names>Seungkwan</given-names></name><xref ref-type='aff' rid='aff1'></xref></contrib><aff id='aff1'>School of Civil, Environmental & Architectural Engineering, Korea University, 1, 5-ga, Anam-Dong, Sungbuk-Gu, Seoul, 136-713, Korea E-mail: <email>skhong21@korea.ac.kr</email></aff><aff id='aff2'>Environment G. Emerging Tech, Center/SAIT Samsung Electronics, Korea</aff></contrib-group><volume>13</volume><issue>2</issue><fpage>265</fpage><lpage>272</lpage><history><date date-type='received'><day>30</day><month>4</month><year>2012</year></date><date date-type='accepted'><day>6</day><month>9</month><year>2012</year></date></history><permissions><copyright-statement>© IWA Publishing 2013</copyright-statement><copyright-year>2013</copyright-year></permissions><abstract ><P>Biofouling caused by the deposition or growth of microorganisms on the membrane surface is one of the major concerns in nanofiltration (NF) and reverse osmosis (RO) processes. Assimilable organic carbon (AOC) has been a useful index to assess the growth potential of bacteria. In the case of drinking water, the AOC assay method has been widely applied to estimate growth or regrowth potential of bacteria in distribution and storage systems. However, studies on AOC measurement for high salinity water samples such as brackish water and seawater are rather scarce. The objective of this research is to investigate the influence of water salinity on the conventional AOC assay method. AOC samples with different salt concentrations were prepared by varying NaCl concentration from 0 to 35,000 mg/L, while the acetate concentration was held at 100 μg/L. The number of cells produced in water samples was measured by the heterotrophic plate count (HPC) method using R2A agar. The result showed that the cell production of <I>Pseudomonas fluorescens</I> strain P17 and <I>Spirillum</I> strain NOX decreased with increasing salinity. Especially, the growth of <I>Spirillum</I> strain NOX was noticeably influenced by water salinity. To further observe the relation between acetate concentration and cell production in high salinity water, organic-free saline water
Kim, Jungbin,Hong, Seungkwan Elsevier Scientific Pub. Co 2018 Desalination Vol. No.
<P><B>Abstract</B></P> <P>Seawater reverse osmosis (SWRO) desalination is required to produce high-quality water to meet stricter water standards, which could be satisfied with single-pass RO through the advancement of reverse osmosis (RO) membranes. In this study, a novel single-pass RO configuration was proposed to further improve permeate quality. Split partial single-pass (SSP) RO is a design in which the permeate from the rear RO element(s) in a pressure vessel is blended with the RO feed. This blending resulted in the dilution of the feed, leading to the production of high-quality permeate with lower energy demand. Modeling of the RO process demonstrates that SSP RO had the highest energy efficiency when the permeate from the 7th element (i.e., the last one in the single pass RO configuration) was circulated back and mixed with the feed. For typical SWRO operating conditions, SSP RO was effectively able to improve permeate quality. In fact, SSP RO produced an approximately 15% purer permeate compared to conventional single-pass RO. SSP RO was also always more energy-efficient than the two-pass RO configurations. The economic feasibility of the design was assessed further and the possibility of its practical application explored.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new single-pass RO configuration was proposed for high-purity permeate production. </LI> <LI> SSP RO required low hydraulic pressure and can mitigate fouling due to feed dilution. </LI> <LI> A purer permeate was obtained without the need for second-pass RO. </LI> <LI> The SSP RO was energy-efficient compared to the two-pass RO systems. </LI> <LI> The SSP RO was the most economical RO design that still met TDS standards. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>