• 제목/요약/키워드: MF(Microfiltration)/UF(Ultrafiltration)

검색결과 39건 처리시간 0.019초

Effect of $N_2$-backflushing Time in Carbon Ceramic UF & MF System for Paper Wastewater Treatment

  • Park, Jin-Yong
    • Korean Membrane Journal
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    • 제7권1호
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    • pp.34-41
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    • 2005
  • The wastewater discharged from a paper plant was filtrated by 3 kinds of tubular carbon ceramic UF and MF membranes with $N_2$-backflushing. The filtration time (FT) was fixed at 8 min or 16 min, and $N_2$-backflushing time (BT) was changed in 0${\~}$60 sec. The optimal condition was discussed in the viewpoints of total permeate volume ($V_T$), dimensionless permeate flux (J/Jo) and resistance of membrane fouling ($R_f$). In the viewpoints of $V_T$, J/Jo and $R_f$, the optimal $N_2$-BT was 40 sec at both FT for M9 (MWCO: 300,000 Daltons) and C005 ($0.05{\mu}m$) membranes. However, for C010 ($0.1{\mu}m$) it was 10 sec at FT=8 min, and 20 sec at FT=16 min in the viewpoints of J/Jo and $R_f$, and 5 sec at both FT in the viewpoints of $V_T$. It means that the short $N_2$-BT could reduce the membrane fouling and recover the permeate flux sufficiently for MF membrane having a large pore size as C010. Average rejection rates of pollutants were higher than $99.0\%$ for turbidity and $22.8{\~}59.6\%$ for $COD_{cr}$, but rejection rates of total dissolved solid (TDS) were lower than $8.9\%$. Therefore, the low turbidity water purified in our system could be reused for paper process.

초음파를 이용한 침출수 처리를 위한 막분리 공정의 막힘현상 개선(II) : 막의 재질, 용질과 복합초음파의 효과 분석 (Improvement of Fouling in Membrane Separation Process for Leachate Treatment using Ultrasound(II) : Analysis of Membrane Materials, Solutes and Multi-ultrasonic Effect)

  • 김석완;임재림;이준걸
    • 대한환경공학회지
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    • 제28권2호
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    • pp.207-215
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    • 2006
  • 본 연구에서는 화학적 1차 처리 침출수(시료 I)와 생물학적 처리 침출수(시료 II)를 대상으로 한 막 분리 공정에서 막의 막힘현상을 개선하기 위한 기술로서 초음파 조사방법을 도입하여 그에 대한 영향을 평가하였다. 초음파의 투과속도 개선효과에 관한 실험은 주기적으로 초음파를 조사할 수 있는 초음파막 분리장치를 제작하여 막의 재질(PS과 PVDF)과 막의 종류(MF와 UF), 초음파의 단일주파수(40 kHz와 120 kHz), 초음파의 세기(200 W와 400 W)에 따라 실시하였으며. 아울러 40 kHz와 120 kHz를 동시에 사용하는 복합초음파 조사 실험을 실시하였다. 주기적인 초음파 조사에 관한 시나리오 실험을 통해 UF막과 MF막을 비교한 결과 MF계열의 막에서 더 높은 투과속도의 개선효과를 나타냈으며, 두 가지 PS와 PVDF재질로 만들어진 MF막의 경우 PVDF재질의 MF막이 더 높은 개선효과를 지속적으로 나타내었다. 또한 용액(폐수)의 특성에 따라 초음파 조사에 의한 투과속도의 개선효과가 다르게 나타났으며, 두 가지 초음파주파수(40 kHz과 120 kHz)를 동시에 활용한 복합초음파를 주기적으로 조사한 경우에 투과속도의 상승률은 세정효과가 큰 낮은 주파수(40 kHz)의 단일초음파를 이용하는 경우보다 작았으나, 재막힘 현상은 복합초음파를 사용하는 경우가 더 크게 억제되어 막의 투과속도 개선효과가 지속적으로 유지되었다.

Pretreatment in Reverse Osmosis Seawater Desalination: A Short Review

  • Valavala, Ramesh;Sohn, Jin-Sik;Han, Ji-Hee;Her, Nam-Guk;Yoon, Yeo-Min
    • Environmental Engineering Research
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    • 제16권4호
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    • pp.205-212
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    • 2011
  • Reverse osmosis (RO) technology has developed over the past 40 years to control a 44% market share in the world desalting production capacity and an 80% share in the total number of desalination plants installed worldwide. The application of conventional and low-pressure membrane pretreatment processes to seawater RO (SWRO) desalination has undergone accelerated development over the past decade. Reliable pretreatment techniques are required for the successful operation of SWRO processes, since a major issue is membrane fouling associated with particulate matter/colloids, organic/inorganic compounds, and biological growth. While conventional pretreatment processes such as coagulation and granular media filtration have been widely used for SWRO, there has been an increased tendency toward the use of ultrafiltration/microfiltration (UF/MF) instead of conventional treatment techniques. The literature shows that both the conventional and the UF/MF membrane pretreatment processes have different advantages and disadvantages. This review suggests that, depending on the feed water quality conditions, the suitable integration of multiple pretreatment processes may be considered valid since this would utilize the benefits of each separate pretreatment.

Roles of polypropylene beads and pH in hybrid water treatment of carbon fiber membrane and PP beads with water back-flushing

  • Song, Sungwon;Park, Yungsik;Park, Jin Yong
    • Membrane and Water Treatment
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    • 제10권2호
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    • pp.155-163
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    • 2019
  • The roles of polypropylene (PP) beads and pH on membrane fouling and treatment efficiency were investigated in a hybrid advanced water treatment process of tubular carbon fiber membranes (ultrafiltration (UF) or microfiltration (MF)) and PP beads. The synthetic feed including humic acid and kaolin flowed inside the membrane, and the permeated contacted the PP beads fluidized in the space between the membrane and the module with UV irradiation and periodic water back-flushing. In the hybrid process of UF ($0.05{\mu}m$) and PP beads, final resistance of membrane fouling ($R_f$) after 180 min increased as PP beads increased. The turbidity treatment efficiency was the maximum at 30 g/L; however, that of dissolved organic matters (DOM) showed the highest at PP beads 50 g/L. The $R_f$ strengthened as pH of feed increased. It means that the membrane fouling could be inhibited at low alkali condition. The treatment efficiency of turbidity was almost constant independent of pH; however, that of DOM showed the maximum at pH 5. For MF ($0.1{\mu}m$), the final $R_f$ was the minimum at PP beads 40 g/L. The treatment efficiencies of turbidity and DOM were the maximum at PP beads 10 g/L.

Effect of growth phase of cyanobacterium on release of intracellular geosmin from cells during microfiltration process

  • Matsushita, Taku;Nakamura, Keisuke;Matsui, Yoshihiko;Shirasaki, Nobutaka
    • Membrane and Water Treatment
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    • 제6권3호
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    • pp.225-235
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    • 2015
  • During low-pressure membrane treatments of cyanobacterial cells, including microfiltration (MF) and ultrafiltration (UF), there have reportedly been releases of intracellular compounds including cyanotoxins and compounds with an earthy-musty odor into the water, probably owing to cyanobacterial cell breakage retained on the membrane. However, to our knowledge, no information was reported regarding the effect of growth phase of cyanobacterial cells on the release of the intracellular compounds. In the present study, we used a geosmin-producing cyanobacterium, Anabaena smithii, to investigate the effect of the growth phase of the cyanobacterium on the release of intracellular geosmin during laboratory-scale MF experiments with the cells in either the logarithmic growth or stationary phase. Separate detection of damaged and intact cells revealed that the extent of cell breakage on the MF membrane was almost the same for logarithmic growth and stationary phase cells. However, whereas the geosmin concentration in the MF permeate increased after 3 h of filtration with cells in the logarithmic growth phase, it did not increase during filtration with cells in the stationary phase: the trend in the geosmin concentration in the MF permeate with time was much different between the logarithmic growth and stationary phases. Adsorption of geosmin to algogenic organic matter (AOM) retained on the MF membrane and/or pore blocking with the AOM were greater when the cells were in the stationary phase versus the logarithmic growth phase, the result being a decrease in the apparent release of intracellular geosmin from the stationary phase cells. In actual drinking water treatment plants employing membrane processes, more attention should be paid to the cyanobacterial cells in logarithmic growth phase than in stationary phase from a viewpoint of preventing the leakage of intracellular earthy-musty odor compounds to finished water.

염색폐수의 처리를 위한 세라믹 분리막에 대한 고찰 (A Review on Ceramic Based Membranes for Textile Wastewater Treatment)

  • 곽연수;라즈쿠마 파텔
    • 멤브레인
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    • 제32권2호
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    • pp.100-108
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    • 2022
  • 다양한 산업 중에서 섬유 산업은 섬유 염색을 위해 가장 많은 양의 물을 사용하는데, 이는 여러 종류의 염료를 포함한 폐수의 방대한 배출로 이어진다. 염료의 제거를 위한 방법에는 오존 처리, 흡착 등의 다양한 처리 방법이 존재한다. 하지만 이러한 처리 방법은 폐수 재사용의 문제로 인해 처리 가격이 상승하기 때문에 성공적이지 못하다. 이에 대한 대안으로 막분리 공정이 폐수의 염료 처리를 위한 가장 적절한 기술로 보고되고 있다. 이때 사용되는 분리막은 고분자 분리막과 세라믹 분리막으로 나눌 수 있다. 세라믹 분리막의 장점에는 세척의 용이함, 긴 수명, 내열성, 내화학성, 그리고 기계적 안정성이 있다. 세라믹 분리막은 다양한 원료로 만들 수 있으며, 점토, 제올라이트, 플라이 애시와 같은 천연 재료는 저렴하고 구하기 용이하다. 본 리뷰에서 폐수처리는 크게 한외여과(ultrafiltration), 정밀여과(microfiltration), 그리고 나노여과(nanofiltration) 세가지 공정으로 나누어져 있다.

초음파를 이용한 침출수 처리를 위한 막분리 공정의 막힘현상 개선(I) : 초음파의 영향인자 평가 (Improvement of Fouling in Membrane Separation Process for Leachate Treatment using Ultrasound(I) : Analysis of Ultrasonic Parameters)

  • 김석완;임재림;이준걸
    • 대한환경공학회지
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    • 제28권2호
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    • pp.197-206
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    • 2006
  • 본 연구에서는 최근 매립지 침출수 처리를 위해 많이 활용되고 있는 막분리 공정에 초음파를 적용하여 투과속도와 막의 세정효율 향상에 미치는 영향인자와 효과에 대하여 살펴보았다. 즉, 중공사 형태의 MF막과 관형의 UF막을 대상으로 초음파의 주파수($40{\sim}120$ kHz), 초음파의 세기($200{\sim}500$ W), 운전압력($0.1{\sim}2.3kg/cm^2$), 초음파 조사시간 등을 변화시키며 투과속도 향상에 미치는 영향을 평가하였다. 1차 처리된 침출수를 이용하여 초기 50 min 동안 막을 오염시킨 다음 70 min 동안 초음파를 조사하여 조사기간과 투과속도의 변화를 관찰하였다. 순수의 투과속도에 대한 투과속도의 회복률(recovery ratio)과 세정직전의 투과속도에 대한 초음파 조사 후 투과속도의 상승률(enhancement ratio)을 이용하여 영향인자를 분석하였다. 동일한 조건에서 막의 초음파 세정에 의한 투과속도 개선 효과는 주파수에 반비례적이며. 초음파의 조사강도에 비례적으로 나타났고, 막의 운전압력이 높으면 세정효과가 지연되며 투과속도의 개선효과도 감소하였다. 또한 10,000과 100,000 MWCO의 UF막에서의 회복율과 상승률은 각각 최대 75-98%와 40-50% 이었으나, $0.1{\mu}m$ MF막에서는 각각 10%와 500%였다. 1차 처리 침출수를 이용한 실험결과로부터 초음파에 의해 발생되는 기계적 진동을 활용한 막세정이 기존의 수세정과 약품세정 대신에 활용가능성이 확인되었다.

오존산화/응집 혼성공정에 의한 UF 분리막의 막오염 저감에 관한 연구 (A study on mitigation of membrane fouling by ozonation/coagulation in ultrafiltration)

  • 김건엽;김민규;이창하;김형수;김지훈;이경일
    • 상하수도학회지
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    • 제31권2호
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    • pp.161-168
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    • 2017
  • Microfiltration (MF) and Ultrafiltration (UF) membrane processes capable of producing highly purified water have been extensively applied as a pretreatment process in the wastewater reuse field with the improvement of membrane properties and resistance, development of operating protocols, and improvement of technologies of backwashing and physicochemical cleaning, and improvement of scale and antifoulants. However, despite of the development of membrane production and process technologies, fouling still remains unresolved. This study confirmed that foulants such as polysaccharides, proteins and humic substances existed in final treated effluent (secondary effluent) by fluorescence excitation emission matrix (FEEM) and fourier transform infrared spectroscopy (FTIR) analysis. In addition, when constructing ozone oxidation and coagulation processes as a hybrid process, the removal efficiency was 5.8%, 6.9%, 5.9%, and 28.2% higher than that of the single process using coagulation in turbidity, color, dissolved organic carbon (DOC), and UV254, respectively. The reversible and irreversible resistances in applying the hybrid process consisting of ozone oxidation and coagulation processes were lower than those in applying ozone oxidation and coagulation processes separately in UF membrane process. Therefore, it is considered possible to apply ozonation/coagulation as a pretreatment process for stable wastewater reuse by and then contributing to the reduction of fouling when calculating the optimal conditions for ozone oxidation and coagulation and then to applying them to membrane processes.

Progresses in membrane and advanced oxidation processes for water treatment

  • Khulbe, K.C.;Feng, C.Y.;Matsuura, T.;Ismail, A.F.
    • Membrane and Water Treatment
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    • 제3권3호
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    • pp.181-200
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    • 2012
  • At present water crisis is not an issue of scarcity, but of access. There is a growing recognition of the need for increased access to clean water (drinkable, agricultural, industrial use). An encouraging number of innovative technologies, systems, components, processes are emerging for water-treatment, including new filtration and disinfectant technologies, and removal of organics from water. In the past decade many methods have been developed. The most important membrane-based water technologies include reverse osmosis (RO), ultrafiltration (UF), microfiltration (MF), and nanofiltration. Beside membrane based water-treatment processes, other techniques such as advanced oxidation process (AOP) have also been developed. Some unconventional water treatment technology such as magnetic treatment is also being developed.

수처리용 분리막 모듈 설계 및 오염 방지

  • 정건용
    • 한국막학회:학술대회논문집
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    • 한국막학회 1997년도 심포지움시리즈 Jan-97 수처리용 분리막 기술 및 응용
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    • pp.87-109
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    • 1997
  • Reverse osmosis(R/O), ultrafiltration(UF) and microfiltration (MF) processes are widely used for water treatment. In the seminar, characteristics of typical membrane modules including tubular, hollow fiber, plate and frame and spiral wound types will be discussed in detail. The design methods based on hydrodynamics for hollow fiber and spiral wound modules will be introduced analytically. Concentration polarization (CP) and membrane fouling mechnism as well as the techniques for CP reduction will be handled. The CP control techniques contain chemically modified membrane surface, pretreatment of feed water, operation of low trans-membrane pressure, chemical or physical cleaning methods and artificial production of various fluid turbulences near the membrane surface, etc. In especially, the recent commercial membrane modules for CP control including module rotation, vibration and Taylor or Dean vortex system will be introduced and discussed in detail.

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