MBR 유출수 재활용을 위한 RO 막분리 공정에 대한 연구

윤현수(Yoon, Hyun-Soo),김종수(Kim, Jong-Soo) 한국산학기술학회 2010 한국산학기술학회논문지 Vol.11 No.4

S전자에서 발생되는 유기성 산업폐수의 생물학적 처리인 MBR 공정의 유출수를 LCD 제조공정의 용수로 재사용하기 위하여 32 m3/d 규모의 pilot-scale RO 막분리 공정을 구축하고 RO 막분리 공정의 운전압력과 투과유량 에 따른 막간차압 및 CIP 주기 그리고 TOC와 전기전도도의 용질분리에 대한 영향을 분석하였다. MBR 공정의 유출 수는 일반적인 처리수 재사용 수질기준을 만족하나 LCD 제조공정의 S전자 자체 재사용 용수 수질기준인 TOC<1mg/L와 전기전도도<100 μS/cm를 만족하지 못하므로 후속 처리가 불가피하다. RO 막분리 공정의 회수율을 85%로 일정하게 유지한 상태에서 투과유량을 12.5 LMH에서 22.0 LMH로 증가시키면서 운전한 결과 모든 투과유량 에서 RO 투과수는 자체 재활용 용수 수질기준을 만족하였다. 그러나 RO 막오염에 의한 막간차압이 상승되어 CIP 주기는 투과유량이 증가되면 짧아지는 효과가 나타났다. RO 막분리 공정의 최적 운전인자는 회수율 85%에서 투과 유량 16.5∼18.5 LMH이었으며 운전압력은 6.7∼12.4 kgf/cm2, CIP 주기는 투과생산량/운전비에 적절한 20일∼25일로 나타났다. Reuse feasibility of MBR effluent of S Electronic Company's organic wastewater as a LCD process water was investigated by a 32 ㎥/d pilot-scale RO membrane process. The effects of operating pressure and permeate flux at constant 85% recovery of RO membrane process using MBR effluent were analyzed for transmembrane pressure and period for CIP by membrane fouling as well as rejection of TOC and conductivity. MBR effluent requires additional treatment to meet the LCD process water quality criteria of TOC<1 mg/L and conductivity<100 μS/cm which is stringent as compared with those of conventional reuse water quality criteria. The RO process operated at 85% recovery with stepwise increasing of permeate fluxes from 12.5 LMH to 22.0 LMH was able to meet LCD process water quality criteria. However, the transmembrane pressure increased and the period of CIP decreased as increasing permeability fluxes due to fouling of RO membrane. The optimum operational conditions of RO membrane process were permeate fluxes of 16.5∼18.5 LMH with operating pressure of 6.7∼12.4 kgf/cm2 and CIP period of 20∼25 days at constant 85% recovery.

세라믹막을 이용한 Lactobacillus cell의 농축 공정의 특성

이용택,송민호 한국막학회 2004 멤브레인 Vol.14 No.3

본 연구에서는 유기질막에 비해 안정성이 우수하고 사용수명이 긴 세라믹 막을 이용하여 혐기성 Lactobacillus 균주의 농축에 관해서 연구하였다. Cell harvesting (CH)에 영향을 주는 인자로 막투과 압력, 온도, 선속도 등에 대해 조사하였으며 세라믹 막을 이용하여 농축율 변화에 따른 플럭스와 TMP (transmembrane pressure)의 변화, 일정 VCF(volumetric concentration factor)에서 TMP변화 등의 최적조건에 관해 알아보았다. 그 결과 플럭스는 TMP, 선속도, VCF가 증가함에 따라 투과수량도 증가함을 알 수 있었다. 온도가 증가할수록 점도에 의해 초기 플럭스도 증가하지만 시간이 경과함에 따라 막 표면의 겔층의 형성으로 온도의 영향은 미미하였다. 또한 농축비 이하의 일정한 VCF에서 운전할 경우 플럭스가 안정적임을 알 수 있었다. 선속도 5 m/s, 공급액의 온도 37^℃, TMP 1 bar에서 6∼8 h 운전할 경우 PS 406 원액의 생균수는 4.9x10^9으로 약 8배 농축됨을 알 수 있었다. It is an anaerobic germ that Lactobacillus cell concentrated using ceramic membrane has high stability and long lifetime as compared with polymeric membrane. The effects of operating pressure, temperature, crossflow velocity on cell harvesting have been studied. Also the variation of flux and transmembrane pressure (TMP) with increasing concentration ratio and the change of TMP at constant concentration ratio (volumetric concentration factor: VCF) regarding the optimization have been examined. It showed that the permeate flux increased gradually with the increasing of transmembrane pressure, crossflow velocity, and volumetric concentration factor. The higher initial flux was due to the reduction of viscosity at elevated temperature. However, as operating time progressed, the effect of temperature was negligible since the effect of viscosity became minor. As a result, that operate in a constant concentration ratio, decreased degree could know that become slowly although the flux decreases according as operating time progressed. The flux is a very stable in the condition of constant VCF range. The yield of Latobaciilus (PS 406) which was cultivated at 37^℃ was concentrated about 4.9x10^9 after operation.

응집-분리막시스템 여과시 혼탁수가 막오염에 미치는 영향

현길수 한국수처리학회 2024 한국수처리학회지 Vol.32 No.1

. Humic substances and turbid particles in water sources intended for drinking water can contribute to membrane fouling during membrane filtration processes. This study investigates the effects of filtration characteristics in a coagulation-membrane system on water treatment, particularly using synthetic water containing kaolin (< 60 mg/L) as a colloid and humic acid (< 5 mg/L) as organic matter. Coagulation was performed using a jar test with alum (< 10 gm/L) as a coagulant, followed by a membrane filtration process using a stirred dead-cell filter. The experiments involved increasing the driving pressure and stirring strength at an alum dose of 5 mg/L. The results demonstrated a significant reduction in kaolin levels with increased driving pressure and stirring strength, whereas humic acid remained unaffected. The remaining permeate flux (J/Jo) in the membrane process decreased with increasing driving pressure and decreasing stirring strength. Specifically, at a driving pressure of 30 kPa, J/Jo was 10% lower than that at 50 kPa, whereas at a stirring strength of 100 rpm, J/Jo was 10% higher than that at 50 rpm. Notably, water containing only kaolin exhibited a relatively lower remaining permeate flux than water containing both humic acid and alum with kaolin. The results indicate that both humic acid and alum contribute to particle aggregation in water, but residual alum increases membrane fouling. Therefore, optimal permeate flux can be achieved using lower driving pressure and higher stirring strength at an appropriate coagulant dosage.

Quantitative Analysis of Pulsatile Flow Contribution to Ultrafiltration

Lim, Ki Moo,Park, Joong Yull,Lee, Jung Chan,Kim, Jeong Chul,Min, Byoung Goo,Kang, Eung Taeck,Shim, Eun Bo Blackwell Publishing Inc 2009 Artificial Organs Vol.33 No.1

<P>Abstract</P><P>We evaluated the quantitative contribution of pulsatile flow to ultrafiltration (UF) in terms of fluid power, membrane stretch, and reduction of membrane layering. An in vitro comparison of the UF rate using pulsatile and roller pumps was performed with distilled water and bovine whole blood. The mean transmembrane pressure (TMPm) and UF rate were higher with the pulsatile pump for the same mean flow rate: 6.6 mm Hg and 21.1 mL/min higher on average for distilled water and 34.2 mm Hg and 31.4 mL/min higher on average for blood. The average UF rate was 8.4 mL/min higher with the pulsatile pump for the same TMPm with bovine blood. However, the relationship between the UF rate and the TMPm was independent of the flow configuration for distilled water. We showed that the higher UF rate in the pulsatile pump is mainly due to greater fluid power and reduction of membrane layering, while the membrane stretch was not an important factor.</P>

응집제를 이용한 MBR공정에서 침지형 막의 여과 특성

김경량 ( Kyumg Ryang Kim ),김선일 ( Sun Il Kim ) 조선대학교 공학기술연구원 2011 공학기술논문지 Vol.4 No.1

In the m membrane bioreactor (MBR) process membrane contamination is one of the major problem which leads to reducreduction of permeation flux efficiency by the increase of TMP (transmembrane pressure). The MBR processes using agglomeration compound were developed in order to reduce the TMP. Fhe aim of research is to investigate the charecteristics of membrane filteration in a submerged membrane bioreactor process by the addition of two coagulants such as Al2(SO4)3 and Fecil3. And their optimal coagulant doses were determined. In addition the e two coagulants showed the positive effects on controlling the TMP. Especially, Addition of Fecl3 coagulation could be a main impacts on nitrogen and phosphorus removal. Moreover, their removal efficiencies were higher than the ordinary MBR process.

Prediction Model for Transmembrane Pressure in a Submerged Hollow‐Fiber Microfiltration Membrane

Lee, Hwan‐,Mook,Lee, Chung‐,Hak,Chung, Kun,Lee, Sangho Taylor Francis 2005 Separation science and technology Vol.39 No.8

<P>In this study, a model equation was derived for a submerged, hollow‐fiber microfiltration (MF) membrane under constant flux. The validity of model equation was examined in two aspects: different feed water concentration and membrane pore size. When the concentration of starch solution (feed water) was varied from 1.5 to 9.0 g/L, the model equation predicted transmembrane pressure (TMP) variation at the precision of 99% within that range of concentration. In the cases of a different nominal membrane pore size (0.1 and 0.4 µm), it was capable of predicting TMP variation in a good manner. From experimental TMP data, it was ascertained that different pore sizes of membrane hardly affected filtration time. At the same time, TMP, flux, and total resistance distributions along the membrane length, which cannot be measured directly, could be calculated using the model equation.</P>

Optimization of cross flow filtration system for Dunaliella tertiolecta and Tetraselmis sp. microalgae harvest

Seongkyun Kang,김상우,이진원 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.7

We compared Dunaliella tertiolecta LB999 and Tetraselmis sp. KCTC12236BP harvesting efficiency using cross flow filtration (CFF) method. Filtration membranes with pore size of 0.45 μm and 0.2 μm were selected to determine the efficiency of membrane for harvesting. Cross flow filtration using Dunaliella tertiolecta LB999 with 0.45 μm membrane under transmembrane pressure 0.25 bar was the optimal condition for the laboratory system and the harvesting efficiency was 84.7%.

침지형 막모듈에서 중공사 분산에 따른 여과특성

신춘환,이재인 한국환경과학회 2000 한국환경과학회지 Vol.9 No.2

This study was carried out to investigate the filtration characteristics of membrane modules according to hollow fiber dispersion for direct solid-liquid separation of activated sludge. 2 bundle, 4 bundle, and 10 bundle module used in this experiment according to hollow fiber dispersion was manufactured at laboratory and permeate flux and transmembrane pressure(TMP) of each module were observed under a suction pressure of 0.5㎏_f/㎠. As the hollow fibers were dispersed, permeate flux was increased and TMP was decreased. Permeate flux and TMP of each module was 15.0 ℓ/㎡·h and 31.8 ㎝Hg for 2 bundle, 16.0 ℓ/㎡·h and 17.4 ㎝Hg for 4 bundle, and 20.4 ℓ/㎡·h and 13.8 ㎝Hg for 10 bundle. In conclusion, the membrane fouling is expected to be decrease by maintaining lower TMP with hollow fiber dispersion.

MBR공정의 여과속도가 기질저감과 막여과저항에 미치는 영향

현길수 ( Kil Soo Hyun ) 한국수처리학회 2016 한국수처리학회지 Vol.24 No.4

In this study, the performance of membrane bioreactor (MBR) using a dead-end stirrer cell was conducted to investigate the removal of solid and organic matters from real mixed liquor in aeration tank and membrane fouling. Influent water qualities were on average 30±2 NTU, 36±0.5 mgTOC/L, 22±0.1 mgT-N/L, and 5±0.05 mgT-P/L, 4500±20 mgMLSS/L, respectively. As a result, the membrane biofiltration achieved higher efficiency of more than 90% for solid and organic matters except T-N having lower efficiency less than 35% regardless of permeate flux. An increase in permeate flux resulted in a rise in transmembrane pressure (TMP) and total membrane filtration resistance. This suggests that both lower permeate flux and higher solid retention time are needed to improve membrane filtration resistance and to enhance the efficiency of nitrogen removal by providing nitrification and denitrification in the reactor.

Development of artificial neural networks to predict membrane fouling in an anoxic-aerobic membrane bioreactor treating domestic wastewater

Schmitt, Fé,lix,Banu, Rajesh,Yeom, Ick-Tae,Do, Khac-Uan Elsevier 2018 Biochemical engineering journal Vol.133 No.-

<P><B>Abstract</B></P> <P>An artificial neural network (ANN) was first developed to predict the transmembrane pressure in an anoxic-aerobic membrane bioreactor (AO-MBR) treating domestic wastewater. A few studies about prediction of membrane fouling in MBRs using ANNs have been published so far, even though our recent work indicates that ANNs show a great potential for this application. In this study, 10 parameters linked to wastewater treatment and measured in the different parts of the AO-MBR system were used as the input variables of the ANN. The goal was to select the most relevant input parameters to predict the evolution of the transmembrane pressure based on the performances of the ANN. An ANN model was selected for its satisfying performances (<I>R</I> <SUP>2</SUP> = 0.850). In conclusion, ANNs could be a valid method to predict membrane fouling in AO-MBR systems treating domestic wastewater.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A set of ANNs is first developed to predict membrane fouling in AO-MBR. </LI> <LI> An optimal set of parameters was identified to predict TMP using ANN efficiently. </LI> <LI> High performances were reached (R<SUP>2</SUP> = 0.850) for the developed ANN. </LI> <LI> ANN model have shown high potential to predict membrane fouling. </LI> </UL> </P>