• Title/Summary/Keyword: Permeate quality

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The Study of Biofouling Control and Cause Material in Hybrid Process of Pure Oxygen and Submerged Membrane Bio-reactor (순산소 고율포기시스템 및 침지식 MBR융합공정에서 Biofouling 제어 및 원인물질 규명에 관한 연구)

  • Lee, Sang-Min;Kim, Mi-Hyung
    • Journal of Korean Society on Water Environment
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    • v.27 no.1
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    • pp.44-53
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    • 2011
  • Membrane bio-reactor (MBR) has several advantages over the conventional activated sludge process, including a high biomass, low sludge production, and better permeate quality. Therefore, the MBR have gained popularity for municipal and industrial wastewater treatment. However the MBR usually were used for sewage and low streng th wastewater treatment because of membrane fouling problem and limitation of oxygen transfer into biomass. In this study, the hybrid process combining MBR and pure oxygen was tested for high strength organic wastewater treatment in the COD loading range from 2 to $10kgCOD/m^3{\cdot}day$. The hybrid process, membrane coupled pure oxygen high compact reactor (MPHCR), had been operated for one year and operation parameters, the effect of COD loading, MLSS concentration and the location of membrane module were studied for membrane fouling characteristic. Also membrane resistance test and the component of foulant was analyzed to investigate what is specific foulant in the MBR.

Development of a portable system for monitoring indoor particulate matter concentration (휴대용 실내 미세먼지 농도 측정 장치 개발)

  • Kim, Yoo Jin;Choi, Hyun Seul;Go, Taesik
    • Journal of the Korean Society of Visualization
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    • v.20 no.1
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    • pp.45-51
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    • 2022
  • Airborne particulate matter(PM) has been a global environmental problem. PM whose diameter is smaller than 10 ㎛ can permeate respiratory organs and has harmful effects on human health. Therefore, PM monitoring systems are necessary for management of PM and prevention of PM-induced negative effects. Conventional PM monitoring techniques are expensive and cumbersome to handle. In the present study, two types of PM monitoring devices were designed for measuring indoor PM concentration, portably. We experimentally investigated the performance of three commercial PM concentration measurement sensors in a closed test chamber. As a result, PM2008 sensor showed the best PM concentration measurement accuracy. Linear regression method was applied to convert PM concentration value acquired from PM2008 sensor into ground truth value. A mobile application(app.) was also created for users to check the PM concentration, easily. The mobile app. also provides safety alarm when the PM10 concentration exceeds 81 ㎛/m3. The developed hand-held system enables the facile monitoring of surrounding air quality.

Probabilistic Modeling of Fish Growth in Smart Aquaculture Systems

  • Jongwon Kim;Eunbi Park;Sungyoon Cho;Kiwon Kwon;Young Myoung Ko
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.8
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    • pp.2259-2277
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    • 2023
  • We propose a probabilistic fish growth model for smart aquaculture systems equipped with IoT sensors that monitor the ecological environment. As IoT sensors permeate into smart aquaculture systems, environmental data such as oxygen level and temperature are collected frequently and automatically. However, there still exists data on fish weight, tank allocation, and other factors that are collected less frequently and manually by human workers due to technological limitations. Unlike sensor data, human-collected data are hard to obtain and are prone to poor quality due to missing data and reading errors. In a situation where different types of data are mixed, it becomes challenging to develop an effective fish growth model. This study explores the unique characteristics of such a combined environmental and weight dataset. To address these characteristics, we develop a preprocessing method and a probabilistic fish growth model using mixed data sampling (MIDAS) and overlapping mixtures of Gaussian processes (OMGP). We modify the OMGP to be applicable to prediction by setting a proper prior distribution that utilizes the characteristic that the ratio of fish groups does not significantly change as they grow. We conduct a numerical study using the eel dataset collected from a real smart aquaculture system, which reveals the promising performance of our model.

Hybrid Water Treatment of Tubular Alumina MF and Polypropylene Beads Coated with Photocatalyst: Effect of Nitrogen Back-flushing Period and Time (관형 알루미나 정밀여과와 광촉매 코팅 폴리프로필렌 구의 혼성 수처리: 질소 역세척 주기와 시간의 영향)

  • Park, Jin Yong;Choi, Min Jee;Ma, Jun Gyu
    • Membrane Journal
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    • v.23 no.3
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    • pp.226-236
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    • 2013
  • The effect of $N_2$ back-flushing period (FT) and time (BT) was compared with the previous result used PES (polyethersulfone) beads loaded with titanium dioxide photocatalyst in hybrid process of alumina microfiltration and PP (polypropylene) beads coated with photocatalyst in viewpoints of membrane fouling resistance ($R_f$), permeate flux (J), and total permeate volume ($V_T$). The reason of nitrogen back-washing instead of the general air back-washing method is to minimize the possible effect of oxygen included in air on water quality analysis. As decreasing FT, $R_f$ decreased and J and $V_T$ increased. Treatment efficiency of dissolved organic matters (DOM) was 82.0%, which was the higher than 78.0% of the PES beads result. This means that PP beads coated with photocatalyst was the more effective than PES beads loaded with photo-catalyst in the DOM removal. As increasing BT, the final $R_f$ decreased and the final J increased, but $V_T$ was the maximum at BT 15 sec. The average treatment efficiency of turbidity did not have any trend as changing BT. As BT increasing from 6 sec to 30 sec, the treatment efficiency of DOM increased 11.8%, which was a little higher than the result of PES beads.

Application in Membrane Hybrid System with Acrylic Wastewater Pretreated by $TiO_2$ ($TiO_2$로 전처리한 아크릴 폐수의 Membrane Hybrid System에의 적용)

  • Lee, Kwang-Hyun;Kang, Byung-Chul;Lee, Jong-Baek;Lee, Gang-Choon
    • Membrane Journal
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    • v.19 no.3
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    • pp.183-188
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    • 2009
  • After membrane fouling factors in acrylic wastewater were minimized by pretreatment process accompanied with $TiO_2$, it was utilized in MF/UF/RO process. After composing of ultrafiltration/reverse osmosis or microfiltration/reverseosmosiss module set according to types and kinds of membrane, the separation characteristics were examined with the variation temperature and pressure using pretreated acrylic wastewater by membrane module sets. The permeate of ultrafiltration or microfiltration module was sent to reverse osmosis module. It was found that final permeate flux of reverse osmosis module in module set 2 (MWCO 200,000 UF+RO) was excellent. It was shown that the removal efficiency of TDS, T-N and COD was very low and was not dependent on the variation of temperature and pressure in UF and MF modules. From the above result, the removal efficiency of TDS, T-N and COD was very excellent in RO module. The removal efficiency of turbidity in UF and MF module was very high (> 99% removal efficiency). Final water quality of acrylic wastewater treated by the membrane module set was satisfied with effluent allowances limit and membrane module sets were ascertained to reuse wastewater.

Effects of Membrane Size and Organic Matter on Membrane Fouling (천연유기물질의 특성과 막의 종류에 따른 막오염 메카니즘 분석)

  • Jung, Chul-Woo;Son, Hee-Jong
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.10
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    • pp.1046-1054
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    • 2006
  • The raw water DOC contained 39.3% of hydrophilics, 42.9% of hydriophobic, and 17.8% of transphilic. The hydrophobic fraction in this raw water was mostly fulvic acid. Fulvic acid comprised of 62% and the rest was humic acid(38%). There was more carboxylic acid functional group(64%) than phenolic group(36%). HPI-N and HPI-C comprised of 17% and 22% in the hydrophilic portion, respectively. The fouling mechanisms on the membrane surface and into its porous structure were analyzed in terms of several kinetic models. In order to analyze the fouling kinetics, the various kinetic models described in this paper were used to fit the experimental results. The kinetic models and kinetic constants obtained for each operation condition. The permeate flux was rapidly declined by simultaneous pore blocking and cake formation. Also, the permeate flux declined with decreasing internal pore size resulted from organic deposition into the membrane pore. The results of the membrane fouling test using UF membrane according to NOM fractions. HPI-N caused more fouling than HPI-C. Humic acid caused more fouling than fulvic acid probably due to higher adsorption capacity. Since humic acid has higher adsorption capacity than fulvic acid, it would be more adsorbed onto the membrane pores.

Evaluation of RO Process Feasibility and Membrane Fouling for Wastewater Reuse (하수처리수 재이용을 위한 RO 공정의 타당성 및 막오염 평가)

  • Hong, Keewoong;Lee, Sangyoup;Kim, Changwoo;Boo, Chanhee;Park, Myunggyun;An, Hochul;Hong, Seungkwan
    • Journal of Korean Society on Water Environment
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    • v.26 no.2
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    • pp.289-296
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    • 2010
  • The purpose of this study is to evaluate various pre-treatment methods and proprieties of water quality for wastewater reuse using reverse osmosis (RO) processes. Secondary effluents were sampled from wastewater treatment plants and lab scale pre-treatments and RO filtration test were conducted systematically. Specifically, different types of pre-treatments, such as coagulation, microfiltration and ultrafiltration, were employed to evaluate the removal efficiency of particle and organic matters which may affect the membrane fouling rate. RO process was later added to eliminate trace amounts of remaining organic matters and salt from the raw water for wastewater reclamation. The permeate through the RO process satisfied water quality regulations for industrial water uses. The experimental results showed that the initial fouling tendency differed not only by the feed water properties but also by the membrane characteristics. Membrane fouling was greater for the membranes with large surface roughness, regardless of the hydrophobicity and zeta potentials. Thus both careful consideration of pre-treatment options and proper selection of RO membrane are of paramount importance for an efficient operation of wastewater treatment.

Submerged Type Water Purification System using Hollow Fiber Microfiltration Membrane (중공사 정밀여과막을 이용한 상수처리용 일체형 시스템 개발)

  • Jeong, Gyu-Yeong;Kim, Hyeong-Su;Im, Jong-Seong
    • Journal of Korea Water Resources Association
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    • v.32 no.3
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    • pp.311-319
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    • 1999
  • Membrane separation process is considered as an alternative of conventional water purification system using coagulationㆍsedimentation+sand filtration. In this study, it was examined that the application possibility of Hollowfiber Microfiltration membrane for water purification process. A $20m^3/day$ scale pilot plant was used for studying the possibility of long-term operation and the stability of water quality under the optimum conditions, 0.03m/h permeate flux, filtration for 10 minutes, pause for 2 minutes(including air-scrubbing for 30 seconds), obtained by lab-scale experiment. As a result, it was proved stability of pilot plant over one year and filtrate quality(Turbidity. SS etc). Therefore, it was proved that membrane separation process using Hollowfiber Microfiltration membrane can be applied for water purification system

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Solid-Liquid Separation Characteristics with Bio-filter Media Reactor (여과분리형 생물반응조의 고액분리 특성)

  • Park, Young Bae;Jung, Yong Jun
    • Journal of Wetlands Research
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    • v.16 no.3
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    • pp.347-353
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    • 2014
  • This work was performed to find the effect of operation parameters on the permeate flux through the activated sludge dynamic layer, and to indicate the relationship between the water quality of supernatant and flux based on the results. Since the effluent can be obtained through steady and stable formation of cake layer in the bio-filter media system, it is an important subject to keep and control microbes with activated state in the bio-reactor. Filtration resistance was drastically increased at more than 18000mg/L of MLSS. With filtration time continued, the flux was gradually decreased and the water qualities of supernatant monitored by turbidity and TOC were also deteriorated. This phenomenon indicated that the organic materials generated by microbes and accumulated in the reactor might affect the flux in the system. In addition, the decrease of flux was simultaneously observed in the sludge volume index. When SVI was controlled from 150 to 250, the flux was also decreased. The proper aeration time was recommended to 30 to 60 seconds in this system. In order to operate this system steadily, therefore, the control of water quality of supernatant and SVI should be proceeded.

Characteristics of Membrane Permeability on the Separation of Solid in a Liquid Livestock Manure (축분액비의 고액분리에 있어서 분리막의 투과특성)

  • 황명구;차기철;이명규
    • Journal of Animal Environmental Science
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    • v.6 no.3
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    • pp.175-184
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    • 2000
  • A lab-scale MF membrane reactor was installed to investigate the membrane permeability, characteristics of membrane fouling at each conditions, and quality of permeate (liquid livestock manure) in the separation of solid-matters using membrane. Experiment was divided three filtration type such as follows; continuous filtration, gravity filtration, and intermittent filtration. As a result of experiment, flux 1 LMH was maintained for 7days, and trans-membrane pressure(TMP) was increased gradually under 10cmHg, but it was increased immediately after 10cmHg, respectively. However, the flux was increased, the Tmax was decreased exponential more and more. During the pure-flux test, most of the fouling of membrane was reversible. At the gravity filtration, permeate could be obtained as 1.75 LMH for 3.5days without any other electronic pressure. As an investigation of membrane surface, this study could be decided that the reason of fouling at the lower flux (Run 1 and 2) was attached matters in membrane surface, but at the higher flux (Run 4-6) was concentration polarization.

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