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.

Beyond RO : Future of Seawater Desalination

Seungkwan HONG,Chanhee BOO,DaAe KIM,Yoontaek OH 한국생물공학회 2012 한국생물공학회 학술대회 Vol.2012 No.4

NH₂Cl 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.

해수담수화 농축수 발생 저감을 위한 분리막 고농축 기술 동향 및 에너지 효율 분석

홍승관(Hong, Seungkwan),김정빈(Kim, Jungbin),박기호(Park, Kiho) 대한토목학회 2021 대한토목학회 학술대회 Vol.2021 No.10

중동 시장 진출을 위한 현지맞춤형 저에너지 해수담수화 기술 개발

홍승관(Seungkwan Hong),황문현(Moon-Hyun Hwang),임상규(Sang Kyu Lim),주경훈(Kyoung Hoon Chu),김나영(Nayoung Kim ),박기호(Kiho Park),김정빈(Jungbin Kim) 대한토목학회 2019 대한토목학회지 Vol.67 No.2

고도정수처리공정이 관망의 수질 및 부식에 미치는 영향 : 미 플로리다사례연구

홍승관(Hong Seungkwan),James Taylor,Zhijian Tang,Weizhong Xiao 대한토목학회 2005 대한토목학회논문집 B Vol.25 No.3B

국내·외 해수담수화 적용사례 분석을 통한 미래 시장 및 기술 동향

홍승관 ( Hong Seungkwan ),김정빈 ( Kim Jungbin ) 한국물환경학회 2023 공동춘계 학술발표회 논문집 Vol.2023 No.0

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

New approach for scaling control in forward osmosis (FO) by using an antiscalant-blended draw solution

Gwak, Gimun,Hong, Seungkwan Elsevier 2017 Journal of membrane science Vol.530 No.-

<P><B>Abstract</B></P> <P>In this study, a novel strategy for scaling control in forward osmosis (FO) by employing an antiscalant-blended draw solution is newly suggested. To evaluate its validity, an antiscalant-blended draw solution containing a mixture of NaCl and poly (aspartic acid sodium salt) (PAspNa) was examined by conducting FO experiments under gypsum scaling at various operating modes. Compared with a draw solution composed only of NaCl, the PAspNa-blended draw solution exhibited comparable water flux but significantly lower reverse solute flux. Gypsum fouling tests demonstrated that reversely flowed polymeric anions from the blended draw solution could effectively control membrane scaling, with a scaling inhibition efficiency comparable to that of the direct addition of PAspNa to the feed solution. Sodium hexametaphosphate (SHMP) was also assessed as another scale inhibiting chemical to verify this novel concept. Similar advantages were clearly observed with the SHMP-blended draw solution. The overall results demonstrated that this new scaling control strategy in FO could be extended to various antiscalants that are optimized for specific mineral scales, and thus potentially commercialized in real-world industrial applications, which is vulnerable to membrane scaling.</P> <P><B>Highlights</B></P> <P> <UL> <LI> New strategy using antiscalant-blended draw was proposed for FO scaling control. </LI> <LI> Draw solution was prepared by adopting PAspNa and SHMP with NaCl. </LI> <LI> Reverse solute flux was reduced by employing antiscalant-blended draw solution. </LI> <LI> Membrane scaling in FO was efficiently controlled by reversely flowed antiscalant. </LI> <LI> Scale control by draw-fed antiscalnts is comparable with dosing to feed water. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Fundamentals of Particle Fouling in Membrane Processes

Bhattacharjee Subir,Hong Seungkwan The Membrane Society of Korea 2005 Korean Membrane Journal Vol.7 No.1

The permeate flux decline due to membrane fouling can be addressed using a variety of theoretical stand-points. Judicious selection of an appropriate theory is a key toward successful prediction of the permeate flux. The essential criterion f3r such a decision appears to be a detailed characterization of the feed solution and membrane properties. Modem theories are capable of accurately predicting several properties of colloidal systems that are important in membrane separation processes from fundamental information pertaining to the particle size, charge, and solution ionic strength. Based on such information, it is relatively straight-forward to determine the properties of the concentrated colloidal dispersion in a polarized layer or the cake layer properties. Incorporation of such information in the framework of the standard theories of membrane filtration, namely, the convective diffusion equation coupled with an appropriate permeate transport model, can lead to reasonably accurate prediction of the permeate flux due to colloidal fouling. The schematic of the essential approach has been delineated in Figure 5. The modern approaches based on appropriate cell models appear to predict the permeate flux behavior in crossflow membrane filtration processes quite accurately without invoking novel theoretical descriptions of particle back transport mechanisms or depending on adjust-able parameters. Such agreements have been observed for a wide range of particle size ranging from small proteins like BSA (diameter ${\~}$6 nm) to latex suspensions (diameter ${\~}1\;{\mu}m$). There we, however, several areas that need further exploration. Some of these include: 1) A clear mechanistic description of the cake formation mechanisms that clearly identifies the disorder to order transition point in different colloidal systems. 2) Determining the structure of a cake layer based on the interparticle and hydrodynamic interactions instead of assuming a fixed geometrical structure on the basis of cell models. 3) Performing well controlled experiments where the cake deposition mechanism can be observed for small colloidal particles (< $1\;{\mu}m$). 4) A clear mechanistic description of the critical operating conditions (for instance, critical pressure) which can minimize the propensity of colloidal membrane fluting. 5) Developing theoretical approaches to account for polydisperse systems that can render the models capable of handing realistic feed solutions typically encountered in diverse applications of membrane filtration.