• Proceedings of the Membrane Society of Korea Conference
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• 2003.11a
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• pp.223-225
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• 2003

• Membrane Journal
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• v.2 no.1
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• pp.1-20
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• 1992

Classical membrane processes like microfiltration (MF), ultrafiltration (UF) and reverse osmosis (RO) are being applied in the last years more frequently in environmental and effluent process problems. Newer technologies and developments like pervaporation (PV) and gas sepaxation (GS) recently found commercial applications in the treatment of waste waters and gas streams. The incentive here is either the clean-up from organic components to comply with federal emission regulations or the recovery of the organics for economical reasons. Processes still in their development stage are combinations of chemical reactions with membrane processes to separate and treat $SO_x$ and $NO_x$ laden waste gas streams in the clean-up of stack-gases. In this paper we will first give a short overview of the more recent developments in MF, UF and RO. This is followed by a closer look on newer technologies applied in environmental problems. The applications looked at are the recovery of organic components from solvent laden gas streams and the separation of organic volatiles from aqueous waste waters via pervaporation. Technical solutions, the advantages and disadvantages of the processes and. where possible, cost estimations will be presented.

• Membrane and Water Treatment
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• v.5 no.2
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• pp.73-86
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• 2014

Membrane fouling is a major challenge limiting the use of membrane applications. In this study high induced shear rates were utilized at the membrane surface in order to reduce the organic and inorganic scaling by using the torsional vibration of flat sheet membranes. The performances of a vibratory shear-enhanced processing (VSEP) system for the ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) membrane filtration of industrial dairy wastewater were investigated. The vibration and non-vibration methods were compared with the same membrane and operational parameters during the purification of real dairy industrial process wastewater. In the initial experiments, short-term tests were carried out in which the effects of vibration amplitude, recirculation flow rate and transmembrane pressure were measured and compared. The permeate flux, turbidity, conductivity and chemical oxygen demand (COD) reduction of dairy wastewater were investigated by using UF, NF and RO membranes with vibration and non-vibration methods. In the subsequent experiments, concentration tests were also carried out. Finally, scanning electron microscopy (SEM) revealed that the vibration method gave a better performance, which can be attributed to the higher membrane shear rate, which reduces the concentration of solids at the membrane, and the transmission.

• Magazine of the Korean Society of Agricultural Engineers
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• v.57 no.4
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• pp.16-24
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• 2015

Desalination technology is a process to remove salt from water. There are three classified In accordance with the concentration of salt The concentration of sea water 15,000~50,000mg/l, brackish water 1,500~15,000mg/l, desalination less than 500mg/l.. In general, salt to remove for using a pre-treatment UF filter, but this study is new pre-treatment technology RO Membrane process technology Suspended particulate matter is said most were treated at the pre-treatment equipment, wheat affluent particulate material was removed from the MF filter. Influent SS 16.2mg /l The treatment was effective in treatment 0.05mg /l of 99% is removed. COD is reduced to 60% in the pre-treatment device, after treatment was reduced to 30% RO membrane. Influent COD 10.2mg/l treatment was removed 1.9mg/l. The removal rate is 81.9%. Desalination removes the ionic substances in the RO Membrane. Influent EC $978.8{\mu}s/cm$ and treatment showed a result of $18.7{\mu}s/cm$.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.06a
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• pp.177-189
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• 1996

Raverase osmosis or ultrafiltration systems have generally been regarded as hard to validate about WFI production. Though the Japanese and US Pharmacopoeias have allowed distillation and RO to be applied to WFI production process, only water stills, especially multiple effects have practically been employed for parenteral water production. On the other hand, the latest analysis has shown that even distillate contains such volatile organic matters as trihalomethanes and traces of heavy metals at a little higher concentration than supposed. The JP requires TOC to be monitored in WFI process based on RO or UF systems to control the concentration below 300ppb, but very few monographs or papers have so far been published about the concentrations of organic volatile matters in distillate. (See table 1-1) Therefore, this paper proposes a new applicable WFI systems based on the result of purified water analysis with some membranes used in the process. A well combined membrane system with other units could be expected to provide less amount of impurities in membrane-treated water than in distillate.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.12
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• pp.1273-1280
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• 2008

This study sought to establish the optimum operating condition for the recovery of caustic (NaOH) solution from mercerization in textile process. As main factors, the silt density index (SDI) evaluation of ceramic membrane for the application of nanofiltration/reverse osmosis (NF/RO) membrane, the recovery yield measurement of caustic solution for the application of polymeric membrane, the optimum condition of chemical cleaning for the membrane regeneration, the optimum removal condition of total organic carbon (TOC), turbidity, color, and the permeate flux of ceramic membrane/polymeric membrane combined process were investigated. As results, ceramic ultrafiltration (UF) in the first step and nanofiltration (NF) in the second step were found to be suitable for the removal of total suspended solid (TSS), residual organics, turbidity including color, and the recovery of caustic solution from caustic wastewater stream in mercerization process. When only the ceramic UF membrane was used, the rejection efficiency of both of TSS and turbidity was more than 99.0%, and the color and TOC were rejected about 74.7% and 49.2%, respectively. Meanwhile, the combined membrane precess of UF and NF membranes showed even more efficient removal abilities and thus more than 99.9% of TSS and turbidity, 87.7% of color, and 78.2% of TOC were removed. In particular, 91.3% of NaOH was successfully recovered with 83.7% of total volume in the combined membrane process. With this regard, a clean caustic solution was obtained in a high purity, which can be reused for mercerization process, expecting to offer economical benefits.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.1
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• pp.34-41
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• 2016

Using UF-SWRO hybrid process, pre-blending tests of seawater and brackish water were performed to investigate the effects on removal of boron and humic acid (HA). Feedwater pre-blending was set based on TDS concentration from 15,000 mg/L to 27,000 mg/L and analyzed for boron removal characteristics. Also organics rejection at same TDS concentration range was investigated by injecting HA. Boron concentration appeared to be high as TDS concentration was high ranging from 76.60% to 83.27%, but boron concentration in final produced water was increased up to 0.69 mg/L from 0.48 mg/L. In cases of HA tests at 10 mg/L, 22,500 mg/L TDS appeared to be higher removal rate of 17.59% than a very poor result of 8.43% in 27,000 mg/L. But high HA removal rate of 57.14% was obtained in produced water with 22,500 mg/L TDS containing 10 mg/L of HA and 27,000 mg/L TDS yielded lower boron removal rate of 54.49%. Meanwhile it was found that a relatively high flux and recovery rate were obtained following process when feedwater was injected with HA. It is considered that most of fouling substances were eliminated by binding between HA and $Ca^{2+}$. Thus, when desalination using UF-SWRO with respect to boron and HA, TDS concentration is determined to be advantageous as lower.

• Membrane and Water Treatment
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• v.9 no.5
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• pp.373-383
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• 2018

Fouling by solids and microorganisms is the major obstacle limiting the efficient use of membrane wastewater treatment. In our previous study, two stages microalgae/membrane filtration system was proposed to treat anaerobic digested palm oil mill effluent (AnPOME). This two stages microalgae/membrane filtration system had showed great potential for the treatment of AnPOME with high removal of COD, $NH_3-N$, $PO_4{^{3-}}$, TSS, turbidity, and colour. However, fouling behavior of the membrane in this two stages microalgae/membrane filtration system was still unknown. In this study, empirical models that describe permeate flux decline for dead-end filtration (pore blocking - complete, intermediate, and standard; and cake layer formation) presented by Hermia were used to fit the experimental results in identifying the fouling mechanism under different experimental conditions. Both centrifuged and non-centrifuged samples were taken from the medium with 3 days RT intervals, from day 0 to day 12 to study their influence on fouling mechanisms described by Hermia for ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) filtration mode. Besides, a more detailed study on the use of resistance-in-series model for deadend filtration was done to investigate the fouling mechanisms involved in membrane filtration of AnPOME collected after microalgae treatment. The results showed that fouling of UF and NF membrane was mainly caused by cake layer formation and it was also supported by the analysis for resistance-in-series model. Whereas, fouling of RO membrane was dominated by concentration polarization.

• Membrane Journal
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• v.33 no.3
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• pp.87-93
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• 2023

Electrodialysis (ED) is essential in separating ions through an ion exchange membrane. The disposal of brine generated from seawater desalination is a primary environmental concern, and its recycling through membrane separation technology is highly efficient. Alkali is produced by several chemical industries such as leather, electroplating, dyeing, and smelting, etc. A high concentration of alkali in the waste needs treatment before releasing into the environment as it is highly corrosive and has a chemical oxygen demand (COD) value. The concentration of calcium and magnesium is almost double in brine and is the perfect candidate for carbon dioxide adsorption, a major environmental pollutant. Sodium hydroxide is essential for the metal carbonation process which, is easily produced by the bipolar membrane electrodialysis process. Various strategies are available for its recovery, like reverse osmosis (RO), nanofiltration (NF), ultrafiltration (UF), and ED. This review discusses the ED process by ion exchange membrane for alkali recovery are discussed.

• Proceedings of the Membrane Society of Korea Conference
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• 1996.04a
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• pp.58-59
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• 1996

기체 막분리 공정은 상업적으로 많은 개발의 여지를 가지고 있지만 RO, UF, MF 등과 같은 수처리분야 정도로 공정의 개발 및 실제 응용분야는 매우 미약한 형편이다. 이와 같은 현실에서 최근 청정 에너지로 각광을 받고 있으며 화학공정의 주원료로 잠재적인 수요를 가지고 있는 수소 기체와 지구 온난화 물질 중 가장 대표적인 물질로 주목받고 있는 이산화탄소의 분리를 목적으로 공정 개발의 타당성 연구를 전산모사를 통해서 수행하였다. 본 전산모사의 목적은 공정 형태별 최적의 공정조건 선정을 위한 타당성 연구를 목적으로 하고 있다.