• 대한치과기공학회지
• /
• 제31권2호
• /
• pp.9-14
• /
• 2009

In this study, to improve the flexure strength of Zirconia, on the Zirconia pellet surface measure the flexure strength to melt or permeate the Alumina (Vita Zahnfabrik, Bad Sachkingen, Germany) of private used In-Cream and observe by Scanning election microscope. In the control group(3Y-TZP group), the average of flexure strength was 1623.7MPa, and in the experimental group(Glass-infiltrated 3Y-TZP group) was 1800.2MPa. As a result of observing the interface between glass and zirconia with a scanning election microscope, it was showed that the glass dissolves to permeate into the surface of zirconia, so filled the zirconia with particles.

• 상하수도학회지
• /
• 제18권1호
• /
• pp.73-80
• /
• 2004

This study investigated the phenomena of membrane fouling by NOM and the effect of the fouling on removal of micro-pollutants. NOM has a great effect on decline of permeate flux. Permeate flow rate was reduced by 88% in RO and 34.8% in NF for 323hr operation period. Removal rate of $UV_{254}$, is 87.4% in RO and 78.5% in NF and removal rate of DOC is 42.7% in RO and 32.9% in NF for 2mg/l humic acid. Removal efficiency of the micro-pollutants by the RO and NF membranes fouled by humic acid was mostly lower than that by the new membrane. The concentration polarization which affects the flux and the rejection was thought to occur in the active layer of the membrane, as the membrane was getting fouled.

• Membrane and Water Treatment
• /
• 제5권1호
• /
• pp.57-71
• /
• 2014

In this study, a theoretical model for the transport phenomena in an Air Gap Membrane Distillation used for desalination was developed. The model is based on the conservation equations for the mass, momentum, energy and species within the feed water solution as well as on the mass and energy balances on the membrane sides. The rarefaction impacts are taken into consideration showing their effects on process parameters particularly permeate flow and thermal efficiency. The theoretical model was validated with available data and was found in good agreement especially when the slip condition is introduced. The rarefaction impact was found considerable inducing an increase in the permeate flux and the thermal efficiency.

• 한국막학회:학술대회논문집
• /
• 한국막학회 1996년도 추계 총회 및 학술발표회
• /
• pp.88-89
• /
• 1996

투과증발 시스템은 막 분리 기술의 일종으로 액체 혼합물 중의 한 성분에 대해 친화적인 비다공성 막을 사용하여 그 성분을 선택적으로 투과시켜 혼합물을 분리하는 기술이다. 투과증발 시스템에서는 Feed가 비교적 높은 온도에서 액상 형태로 막의 Feed side에 공급되어 막을 투과한 물질(Permeate)은 Permeate side에서 기화된 후 냉각기로부터 공급되는 Cold brine에 의하여 응축되며, 이는 투과증발막 투과 구동력이 각 성분의 증기압 차이기 때문에 이를 크게 유지하기 위함이다. 현재 투과증발 시스템이 상업적으로 적용되고 있는 공정은 유기물 탈수 공정으로, 이 공정에서는 물에 대한 용해도 및 투과 속도가 우수한 친수성 막을 이용하여 유기물과 물의 혼합물로부터 물을 제거하여 유기물을 농축하며, 대표적인 유기물은 에탄올, Isopropyl alcohol(IPA), 아세톤, MIBK, Ethyl acetate, THF 등의 중성 유기물이다.

• Journal of Dairy Science and Biotechnology
• /
• 제33권2호
• /
• pp.153-157
• /
• 2015

Milk mineral, which is also called milk calcium, was recovered from concentrated skim milk ultrafiltration permeate (CUFP). Lactose, the major constituent of CUFP, was crystallized by the addition of ethanol; lactose precipitation was observed to increase as the ratio of CUFP to ethanol increased. The calcium content of CUFP remained constant at a CUFP to ethanol ratio of 1:2, while it significantly decreased at a CUFP to ethanol ratio of 1:4. When ethanol (95%, v/v) was reused to precipitate lactose out of CUFP, 85% of the initial lactose precipitated out, while 82% of calcium remained soluble in the CUFP after storage for 24 h.

• Membrane and Water Treatment
• /
• 제9권4호
• /
• pp.233-243
• /
• 2018

In this manuscript, $35m^3/d$ NF unit was designed and applied for surface water treatment of the River Nile water. Intake of Embaba drinking water treatment plant was selected to install that unit at since; it has the lowest water quality index value through the examined 6 sites in greater Cairo area. The optimized operating conditions were feed and permeate flow, 40 and $7m^3/d$, feed pressure 2.68 bar and flux rate $37.7l/m^2h$. The permeate water was drinkable according to Egyptian Ministerial decree 458/2007 for the tested parameters (physic-chemical, heavy metals, organic, algal, bacteriological and parasitological). Single and double sand filters were used as pretreatment for NF membranes but continuous clogging for sand filters moved us to use UF membrane as pretreatment for NF membrane.

• KSBB Journal
• /
• 제6권2호
• /
• pp.215-222
• /
• 1991

한외여과막을 이용하여 알부민 용액을 회분식 혼합분리기에서 분리하는 현상들을 연구하였다. 본 연구는 작업시간과 작업압력에 따라 변하는 투과플럭스에 대한 것이다. 또한 실험은 pH 4.8에서 수행되었다. 알부민의 정량은 광학적으로 측정하였으며, Lowry법을 사용하였다. 본 연구 결과는 희박 알부민 용액의 한외여과는 작업시간에 따라 투과량 플럭스가 완만하게 감소되며, 제한된 사용압력에서 알부민 용액의 농도분극 현상은 자석교반에 의해 제기 되었다.

• 멤브레인
• /
• 제7권2호
• /
• pp.84-94
• /
• 1997

Hollow fiber의 diameter와 curvature 및 turn수 등의 변화에 따른 첫번째 모듈 set와 두번째 모듈 set 사이의 성능비교가 이루어졌다. 모든 실험들은 같은 transmembrane pressure와 막면적당 에너지 소모하에서 수행되었다. 첫번째 모듈 set에 대해서 Dean vortices에 의한 농도분극과 막오염현상의 감소시키는 효과가 매우 작음을 알 수 있었다. 두번째 모듈 set에 대해서 115%의 투과 flux 향상값 (투과 flux 증분 ${\times}100$/선형 모듈의 투과 flux)을 보였다. 이로부터 두번째 모듈 set가 yeast suspension에 의한 농도분극과 막오염현상의 감소에 훨씬 효과적임을 알 수 있었다.

• Korean Membrane Journal
• /
• 제11권1호
• /
• pp.21-28
• /
• 2009

We investigated the effect of organic materials on membrane fouling in advanced drinking water treatment by a hybrid module packed with granular activated carbon (GAC) outside multi-channel ceramic microfiltration membrane. Synthetic water was prepared with humic acid and kaolin to simulate natural water resouces consisting of natural organic matter and inorganic particles. Kaolin concentration was fixed at 30 mg/L and humic acid was changed as 2~10 mg/L to inspect the effect of organic matters. Periodic back-flushing using permeate water was performed for 10 sec per filtration of 10 min. As a result, both resistance of membrane fouling (Rf) and permeate flux (J) were influenced highly by concentration of humic acid. It proved that NOM like humic acid could be an important factor on membrane fouling in drinking water treatment. Turbidity and UV254 absorbance were removed up to above 97.4% and 59.2% respectively.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2003년도 생물공학의 동향(XIII)
• /
• pp.175-175
• /
• 2003