• Title/Summary/Keyword: Membrane

Search Result 13,879, Processing Time 0.116 seconds

Effects of membrane orientation on permeate flux performance in a submerged membrane bioreactor

  • Lee, Tsun Ho;Young, Stephanie
    • Membrane and Water Treatment
    • /
    • v.3 no.3
    • /
    • pp.141-149
    • /
    • 2012
  • The aeration provided in a Submerged Membrane Bioreactor (SMBR) improves membrane filtration by creating turbulence on the membrane surface and reducing membrane resistance. However, conventional hollow fiber membrane modules are generally packed in a vertical orientation which limits membrane scouring efficiency, especially when aeration is provided in the axial direction. In the present research, 3 innovative hollow-fiber membrane modules, each with a different membrane orientation, were developed to improve membrane scouring efficiency and enhance permeate flux. Pilot testing was performed to investigate the permeate flux versus time relationship over a 7-day period under different intermittent modes. The results indicated that the best module experienced an overall permeate flux decline of 3.3% after 7 days; the other two modules declined by 13.3% and 18.3%. The lower percentage of permeate flux decline indicated that permeate productivity could be sustained for a longer period of time. As a result, the operational costs associated with membrane cleaning and membrane replacement could be reduced over the lifespan of the module.

Thermo-responsive antifouling study of commercial PolyCera® membranes for POME treatment

  • Haan, Teow Yeit;Chean, Loh Wei;Mohammad, Abdul Wahab
    • Membrane and Water Treatment
    • /
    • v.11 no.2
    • /
    • pp.97-109
    • /
    • 2020
  • Membrane fouling is the main drawback of membrane technology. Frequent membrane cleaning and membrane replacement are, therefore, required to reduce membrane fouling that causes permeate flux reduction, lower rejection, or higher operating pressure. Studies have proved that the alteration of membrane properties is the key controlling factor in lessening membrane fouling. Among stimuli-responsive membranes, thermo-responsive membrane is the most popular, with a drastic phase transition and swelling-shrinking behavior caused by the temperature change. In this study, the thermo-responsive ability of two commercial membranes, PolyCera® Titan membrane and PolyCera® Hydro membrane, at different temperatures was studied on the antifouling function of the membrane in palm oil mill effluent (POME) treatment. The evaluation of the membrane's thermo-responsive ability was done through three cycles of adsorption (fouling) and desorption (defouling) processes in a membrane filtration process. The experimental result depicted that PolyCera® Hydro membrane had a higher membrane permeability of 67.869 L/㎡.h.bar than PolyCera® Titan membrane at 46.011 L/㎡.h.bar. However, the high membrane permeability of PolyCera® Hydro membrane was compensated with low removal efficiency. PolyCera® Titan membrane with a smaller mean pore size had better rejection performance than PolyCera® Hydro membrane for all tested parameters. On the other hand, PolyCera® Titan membrane had a better hydrodynamic cleaning efficiency than PolyCera® Hydro membrane regardless of the hydrodynamic cleaning temperature. The best hydrodynamic cleaning performed by PolyCera® Titan membrane was at 35℃ with the flux recovery ratio (FRR) of 99.17 ± 1.43%. The excellent thermo-responsive properties of the PolyCera® Titan membrane could eventually reduce the frequency of membrane replacement and lessen the use of chemicals for membrane cleaning. This outstanding exploration helps to provide a solution to the chemical industry and membrane technology bottleneck, which is the membrane fouling, thus reducing the operating cost incurred by the membrane fouling.

Membrane Processes for Energy Saving in Japan

  • Nakao, Shin-ichi
    • Proceedings of the Membrane Society of Korea Conference
    • /
    • /
    • pp.45-58
    • /
    • 1994
  • Over the last 20 years, membrane separation processes, such as reverse osmosis, ultrafiltration and microfiltration, have been widely adopted by different industries. Commercial uses of membrane have displaced conventional separation processes, such as distillation, evaporation, precoat filter and so on. Membrane separation processes are often more capital and energy efficient when compared with conventional separation processes. Membrane devices and systems are almost always compact and modular. These are the well-known advantages of membrane separation processes. The disadvantage of the membrane process is that the process does not have scale merit and thus the membrane process is suitable for the small and middle size applications. Energy saving is, of course, the biggest advantage of the membrane process, and in many industries the membrane processes are employed because of this reason. Membrane process has other big advantage. In many applications membrane processes provide much higher quality of product than conventional processes. The example is ultrapure water production by membrane processes in semiconductor industry. Conventional technologies never offer such good quality of pure water. If you can obtain both energy saving and higher quality of product at the same time by membrane processes, this is the best application of membrane processes. One example is the concentration of orange juice by membrane, which has already been commercialized in Japan. Comparing with the conventional vacuum evaporation process, juice concentrated by the membrane process has much better taste and flavor and the energy consumption in the membrane process is much less than the evaporation process. In this paper, first membrane separation technology will be classified and then Japanese membrane manufacturers and new modules and devices under development in Japan will be introduced. Fourth energy saving in membrane process will be discussed and finally practical applications of membrane processes in Japan will be shown.

  • PDF

Study on the Preparation of Polyvinyl Chloride Anion Exchange Membrane as a Separator in the Alkaline Water Electrolysis (알칼리 수전해용 격막으로서 폴리염화비닐(polyvinyl chloride) 음이온교환막의 제조에 관한 연구)

  • Park, Jong-Ho;Bong, Soo-Yeon;Ryu, Cheol-Hwi;Hwang, Gab-Jin
    • Membrane Journal
    • /
    • v.23 no.6
    • /
    • pp.469-474
    • /
    • 2013
  • An anion exchange membrane was prepared for a separator in the alkaline water electrolysis. An anion exchange membrane was prepared by the chloromethylation and amination of polyvinyl chloride (PVC) used as a base polymer. The membrane properties of the prepared anion exchange membrane such as the membrane resistance and ion exchange capacity were measured. The minimum membrane resistance of the prepared anion exchange membrane was $2.9{\Omega}{\cdot}cm^2$ in 1M NaOH aq. solution. This membrane had 2.17 meq./g-dry-membrane and 43.4% for the ion exchange capacity and water content, respectively. The membrane properties of the prepared anion exchange membrane was compared with that of the commercial anion exchange membrane. The membrane resistance decreased in the order; AHT>IOMAC> Homemade membrane> AHA>APS=AFN. The ion exchange capacity decreased in the order; Homemade membrane>AFN>APS>AHT>AHA>IOMAC.

Porous gelatin-based membrane as supports for impregnation of cells (세포함유용 지지체로서 다공성 젤라틴계 막)

  • 이영무;홍성란
    • Membrane Journal
    • /
    • v.11 no.1
    • /
    • pp.29-37
    • /
    • 2001
  • 본 논문은 인공 진피와 조직공학용 scaffold로 이용하기 위해 다공성 membrane로서 gelatin-based sponge의 효율성을 연구하였다. 불용성의 다공성 membrane은 1-ethyl-(3-3dimethylaminopropyl)carbodiimide(EDC)로 가교하여 제조하였다. Fourier-transformed infrared (FT-IR) spectroscopy, scanning electron microscopy(SEM) 그리고 Instron analysis로 다공성 membrane의 특성을 조사하였다. 다공성 membrane은 용적당 큰 표면적을 제공하는 micro porous한 구조를 가지고 있다. Gelatin/hyaluronic acid (HA) membrane의 공경크기는 40~200$\mu\textrm{m}$이다. HA의 첨가는 다공성 membrane의 기계적 강도와 세포부착능력에 영향을 미쳤다. Gelatin/HA 다공성 membrane의 압축강도는 collagen과 비슷하며, 세포배양과 인공진피 transplantation에 있어서의 충분한 기계적 강도를 가지고 있다. Fibroblasts를 함유한 진피기질을 제조하기 위해 직경 8mm의 다공성 membran에 4$\times$10(sup)5cells/membrane의 세포밀도로 fibroblast를 배양하였다. GH91 porous membrane에서의 fibroblast 부착성은 GH55 porous membrane에서보다 우수하였다. 삼차원 구조의 gelatin/HA membrane matrix에서의 fibroblast의 배양은 생체내 조건과 유사한 생리적 환경을 제공하였다.

  • PDF

Modified membrane with antibacterial properties

  • Aryanti, P.T.P.;Sianipar, M.;Zunita, M.;Wenten, I.G.
    • Membrane and Water Treatment
    • /
    • v.8 no.5
    • /
    • pp.463-481
    • /
    • 2017
  • Bacteria have been considered as a major foulant that initiates the formation of biofilm on the polymeric membrane surface. Some polymeric membranes are naturally antibacterial and have low fouling properties, however, numerous efforts have been devoted to improve their antibacterial performance. These modifications are mostly carried out through blending the membrane with an antibacterial agent or introducing the antibacterial agent on the membrane surface by chemical grafting. Currently, a significant number of researches have reported nanocomposite membrane as a new approach to fabricate an excellent antibacterial membrane. The antibacterial nanoparticles are dispersed homogenously in membrane structure by blending method or coating onto the membrane surface. Aim of the modifications is to prevent the initial attachment of bacteria to membrane surface and kill bacteria when attached on the membrane surface. In this paper, several studies on antibacterial modified membranes, particularly for water treatment, will be reviewed comprehensively. Special attention will be given on polymeric membrane modifications by introducing antibacterial agents through different methods, such as blending, grafting, and coating.

Preparation and Application of Functional Carbon Whisker Membrane for Separation Process

  • Bae, Sang-Dae;Son, Hee-Jong;Jung, Chul-Woo
    • Journal of Environmental Science International
    • /
    • v.17 no.11
    • /
    • pp.1235-1241
    • /
    • 2008
  • Membrane separation is extensively used for water/wastewater treatment because of its efficiency separation processes. However, particles in the feed water can deposit and accumulate on the membrane surface to created cake layer. As a consequence, the selectivity of the membrane and flux through the membrane are decreased, which is called fouling/blocking phenomenon. In order to solve fouling problem, we developed a novel membrane named Carbon Whisker Membrane (CWM) which contains vapor-grown carbon fibers/whiskers on the surface of the membrane and a layer of carbon film coated on the ceramic substrate. We firstly employed polymethyl methacrylate (PMMA) as a testing material to investigate the fouling mechanism. The results suggested that Carbon Whiskers on the surface of the membrane can prevent the directly contact between the membrane body and particles so that the fouling/blocking could not occurred easily compared to the membrane without carbon whiskers. We also researched the relationship with the diameter, density of carbon whisker on the membrane surface and total flux of solutions. Finally, we will be able to control the diameter and density of carbon whiskers on the membrane and existence of carbon whiskers on the membrane, it is important factor, might be prevent fouling/blocking in the water treatment.

Tests of Fire and Flame Retardant Performance for Membrane Materials (막재료의 난연 및 방염성능 실험에 대한 연구)

  • Kim, Gee-Cheol;Choi, Kwang-Ho
    • Journal of Korean Association for Spatial Structures
    • /
    • v.16 no.2
    • /
    • pp.55-60
    • /
    • 2016
  • The Membrane structure has a number of problems in the application of a fireproof code based on general buildings codes. Thus, the fireproof code of membrane structure is necessary to activate the construction of the membrane structure. Because it requires a systematic classification of fire retardant and flame proof performance of membrane material. Fire retardant and flame proof tests are conducted on membrane materials mostly used in current construction to propose the fire and flame retardant performance criteria of membrane materials. Fire and flame retardant tests results, PTFE membrane material with the glass fiber fabric have a limit-combustible performance. PVDF membrane material with the polyester fabric does not ensure the fire retardant performance, but this membrane material has the flame retardant performance of a thick fabric. Also, ETFE does not ensure the fire retardant performance, but this membrane material has the flame retardant of a thin fabric.