• Title/Summary/Keyword: reverse osmosis membrane

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Pretreatment of Acrylic Wastewater and Application of UF/RO Processes (Acrylic 폐수의 전처리 및 UF/RO공정의 적용)

  • 이광현
    • Membrane Journal
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    • v.11 no.4
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    • pp.152-160
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    • 2001
  • The pretreatment for COD removal of acrylic wastewater and separation characteristics of ultrafiltration hollow fiber type module and reverse osmosis spiral wound type module with the variation of applied pressure and temperature were discussed. Thc optimum washing time of membranes was decided with long team operation and the degree of fouling was discussed with operating time. Permeate flux was decreased rapidly at 14 hrs and that of reverse osmosis membrane was indicated similarly. CaO find sand filter for the first step, neutralization process with treated acrylic wastewater as the second step, UF/RO processes were used as final strep. It was shown treat COD and TDS were below allowable discharge value with the result.

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Separation of Zinc Ion from Metal Plating Wastewaters by Reverse Osmosis Membrane (Membrane을 이용한 도금폐수 중 아연이온의 분리에 관한 연구)

  • 장자순;이효숙;정헌생;이원권
    • Membrane Journal
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    • v.4 no.2
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    • pp.106-112
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    • 1994
  • The ultrafiltration(UF) and reverse osmosis(RO) tests for a model metal plating wastewater prepared with zinc sulfate, showed the zinc ion rejection coefficient of over 99% and the permeate flux of $1.49 {\times} 10^{-3}cm/sec$ at pH = 8.3. The effect of cyanide on the zinc removal was investigated. When the amount of cyanide addition was same the zinc content, the zinc was removed over 99% and the cyanide was excluded about 93%. The addition of the surfactants such a LAS-Na and EDTA-Na was found to reduce the permeate flux down to $0.76 {\times} 10^{-3}cm/sec$ at the RO membrane.

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Two Dimensional (2D) Nanomaterials based Composite Membrane for Desalination (2차원 나노재료 기반 복합막을 이용한 해수담수화)

  • Lee, Yu Kyung;Patel, Rajkumar
    • Membrane Journal
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    • v.30 no.2
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    • pp.111-123
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    • 2020
  • Growing industrialization and climate change lead to the huge demand for clean drinking water. Desalination of sea water by membrane separation process is one of the alternative and economically viable methods to fulfil the demand for water. In the membrane separation process, the presence of 2D materials enhances the performance of membrane by facilitating the water permeation, salt rejection, flux rate, and selectivity compared to the traditional reverse osmosis thin-film-composite membranes. In this review, composite membranes with different kinds of 2D materials are discussed on the basis of materials synthesis, characterization and desalination process.

A novel approach to bind graphene oxide to polyamide for making high performance Reverse Osmosis membrane

  • Raval, Hiren D.;Das, Ravi Kiran
    • Membrane and Water Treatment
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    • v.8 no.6
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    • pp.613-623
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    • 2017
  • We report the novel thin film composite RO membrane modified by graphene oxide. The thin film composite RO membrane was exposed to 2000 mg/l sodium hypochloride; thereafter it was subjected to different graphene oxide concentration ranging from 50 mg/l to 1000 mg/l in water. The resultant membrane was crosslinked with 5000 mg/l N-hydroxysuccinimide. The performance of different membranes were analysed by solute rejection and water-flux measurement. It was found that 100 mg/l graphene oxide exposure followed by 5000 mg/l N-hydroxysuccinimide treatment resulted in the membrane with the highest solute rejection of 97.78% and water-flux of 4.64 Liter per sqm per hour per bar g. The membranes were characterized by contact angle for hydrophilicity, scanning electron micrographs for surface morphology, energy dispersive X-Ray for chemical composition of the surface, Atomic force microscope for surface roughness, ATR-FTIR for chemical structure identification. It was found that the graphene oxide modified membrane increases the salt rejection performance after exposure to high-fouling water containing albumin. Highly hydrophilic, antifouling surface formation with the nanomaterial led to the improved membrane performance. Moreover, the protocol of incorporating nanomaterial by this post-treatment is simple and can be applied to any RO membrane after it is manufactured.

Evaluation on Chemical Cleaning Efficiency of Organic-fouled SWRO Membrane in Seawater Desalination Process (해수담수화 공정에서 역삼투막의 유기 막오염에 대한 SWRO 막의 화학세정 효율 평가)

  • Park, Jun-Young;Hong, Sung-Ho;Kim, Ji-Hoon;Jeong, Woo-Won;Nam, Jong-Woo;Kim, Young-Hoon;Jeon, Min-Jung;Kim, Hyung-Soo
    • Journal of Korean Society of Water and Wastewater
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    • v.25 no.2
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    • pp.177-184
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    • 2011
  • Membrane fouling is an unavoidable phenomenon in operation of seawater reverse osmosis (SWRO) and major obstacle for economic and efficient operation. When fouling occurs on the membrane surface, the permeate flux is decreased, on the contrary, the trans-membrane pressure (TMP) is increased, therefore operation and maintaining costs and potential damage of membranes are able to the pivotal risks of the process. Chemical cleaning process is essential to prevent interruptions for effective RO membrane filtration process. This study focused on proper chemical cleaning condition for polyamide RO membranes of 4 companies. Several chemical agents were applied for chemical cleaning under numbers of operating conditions. Additionally, a monitoring tool of FEEM as autopsy analysis method is adapted for the prediction of organic bio-fouling.

Feasibility of a two step microfiltration and reverse osmosis membrane system for reuse of tunnel wastewater (터널폐수 재이용을 위한 통합형 멤브레인 시스템의 적용)

  • Lee, Jae-Hyun;Jeong, Se-Uk;Kim, Young Mo
    • Journal of Korean Society of Water and Wastewater
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    • v.27 no.6
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    • pp.779-785
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    • 2013
  • This study investigated the applicability of a two step microfiltration(MF) and reverse osmosis(RO) membrane system for reuse of tunnel wastewater. In this two step process, the MF system first treated only micropollutants in tunnel wastewater such as suspended solids(SS) and heavy metals, achieving less than 0.2 NTU turbidity, less than 1.1 mg/L chemical oxygen demand($COD_{Mn}$) and less than 0.8 mg/L total manganese(Mn). The RO system then removed over 95 % of the remaining pollutnats and particles, resulting in less than 0.02 NTU turbidity, less than 0.5 mg/L chemical oxygen demand($COD_{Mn}$), less than 0.04 mg/L total nitrogen(T-N) and less than 0.01 mg/L total phosphorus(T-P). In particular, addition of an RO system could lead to markedly reduced high salt concentrations in tunnel wastewater, approaching almost zero. Thus, reclaimed water using the combined membrane system could satisfy current South Korean regulations concerning wastewater reuse(turbidity ${\leq}2.0$ NTU; T-N ${\leq}10mg/L$; T-P ${\leq}0.5mg/L$; Salinity ${\leq}250mg{\cdot}Cl/L$).

The removal of nitrogen & phoshorus for the swine wastewater by VSEP membrane system (진동막 분리장치를 이용한 축산폐수의 질소.인 제거에 관한 연구)

  • 지은상;김재우;신대윤
    • Journal of environmental and Sanitary engineering
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    • v.15 no.3
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    • pp.31-36
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    • 2000
  • Conventional membrane systems was difficults to treatment for the swine waste water. Technological advances in membrane filtration systems have created opportunity for the swine wastewater to treat effluent streams in order to meet stricter environmental constraints. "Vibratory Shear Enhanced Processing(VSEP)" developed by new logic international makes it possible to filter effluent streams without the fouling problem exhibited by conventional membrane systems. Various kinds of waste water occurred to and swine wastewater experiment with "VSEP" set up conventional reverse osmosis membrane (ACM-4, ESPA, BW-30). The results were as followes : Treatment efficiency for the input COD(From $332mg/{\ell}$ to $4,968mg/{\ell}$) was 98%. Treatment efficiency for the input SS(From $140mg/{\ell}$ to $4,040mg/{\ell}$) was 100%(All together). Treatment efficiency for the input T-N(From $155mg/{\ell}$ to $934mg/{\ell}$) was 97%~99.8%. Treatment efficiency for the input T-P(From $28.6mg/{\ell}$ to $132mg/{\ell}$) was 99.7% and up. ESPA membrane excels three types of reverse osmosis membranes applied VSEP in removal efficiency.

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Chemical cleaning effects on properties and separation efficiency of an RO membrane

  • Tu, Kha L.;Chivas, Allan R.;Nghiem, Long D.
    • Membrane and Water Treatment
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    • v.6 no.2
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    • pp.141-160
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    • 2015
  • This study aims to investigate the impacts of chemical cleaning on the performance of a reverse osmosis membrane. Chemicals used for simulating membrane cleaning include a surfactant (sodium dodecyl sulfate, SDS), a chelating agent (ethylenediaminetetraacetic acid, EDTA), and two proprietary cleaning formulations namely MC3 and MC11. The impact of sequential exposure to multiple membrane cleaning solutions was also examined. Water permeability and the rejection of boron and sodium were investigated under various water fluxes, temperatures and feedwater pH. Changes in the membrane performance were systematically explained based on the changes in the charge density, hydrophobicity and chemical structure of the membrane surface. The experimental results show that membrane cleaning can significantly alter the hydrophobicity and water permeability of the membrane; however, its impacts on the rejections of boron and sodium are marginal. Although the presence of surfactant or chelating agent may cause decreases in the rejection, solution pH is the key factor responsible for the loss of membrane separation and changes in the surface properties. The impact of solution pH on the water permeability can be reversed by applying a subsequent cleaning with the opposite pH condition. Nevertheless, the impacts of solution pH on boron and sodium rejections are irreversible in most cases.

Evaulation of Developing New-Fusion Eco-Friendly Biocide on the Reverse Osmosis Membranes (살균에 박리 및 분산 기능이 추가된 친환경살균제에 대한 역삼투(RO)막에서의 효과 검증 연구)

  • Park, Duk Joon;Oh, Eun Jung;Kim, Sung Han;Ahn, Kwang Taek
    • Journal of Korean Society of Environmental Engineers
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    • v.38 no.9
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    • pp.497-503
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    • 2016
  • Eco-friendly biocide that do not have noxious chemicals, have a role of disinfection adding of dispersion and strengthening peer power on RO membranes surfaces. Eco-friendly biocide show an 93% improvement of differential pressures arrival time. Also, eco-friendly biocide's Autopsy result show less the percentage of organic pollutants than currently in using biocide. Adding dispersion & peeling strength power to remove the microorganisms is upgrading. Eco-friendly biocide that have a dispersion and peering power is non-toxicant chemicals and is safe for user.

RECENT DEVELOPMENTS OF MEMBRANE TECHNOLOGY IN JAPAN

  • Kimura, Shoji
    • Membrane Journal
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    • v.1 no.1
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    • pp.5-12
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    • 1991
  • Since the discovery of the Loeb-Sourirajan reverse osmosis membrane, thirty years have passed and many membrane technologies and new membranes for applications have been developed in the world. In the early stage of these developments Japan has not contributed much, but from the middle of 70ties Japan has started its own R&D projects starting from the desalination technology, and now various private industries and government ministries are actively engaging in R & D of membrane technologies in Japan. In Table 1 the chronological developments of important events of developments and projects relating membrane technologies inside and outside of Japan are introduced and their details will be explained. The first membrane technology applied in the Japanese industry was a electrodialysis(ED) process using ion-exchange membranes. These membranes were first developed in early 50ties and the Japanese government decided to use this method for concentration of sea-water to produce salt, which was then produced by solar evaporation. This development program started from 1960 by the Japan Monopoly Corp.(at that time). To apply ED process for sea-water concentration it was necessary to develop ion-exchange membranes having very low electric resistance to avoid energy loss due to Joule heat, and those having selectivity to permeate single valent ions only to avoid scale formation in the ED stacks. Three Japanese companies, Asahi Glass, Asahi Chemical and Tokuyama Soda, have succeeded to develop such membranes, and until 1971 all of the seven salt manufacturing companies had adopted ED for production of food salt.

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