• 상하수도학회지
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• 제28권5호
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• pp.549-554
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• 2014

This study was evaluated the applicability of the membrane filtration process (Micro Filtration (MF), nanofiltration membranes (NF), reverse osmosis (RO)) on the major radioactive substances, iodine ($I^-$) and cesium ($Cs^+$) using membranes produced in Korea and domestic raw water. Iodine ($I^-$) or cesium ($Cs^+$) in the microfiltration membrane (MF) process could not be expected removal efficiency by eliminating marginally at the combined state with colloidal and turbidity material. At the domestic raw water (lake water, turbidity 1.2 NTU, DOC 1.3 mg/L) conditions, nanofiltration membrane (NF) and reverse osmosis (RO) showed a high removal rate of about 88 ~ 99% for iodine ($I^-$) and cesium ($Cs^+$) and likely to be an alternative process for the removal of radioactive material.

• 멤브레인
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• 제19권2호
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• pp.145-149
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• 2009

본 연구의 목적은 나노복합막을 제조하여 가수분해된 세리신 용액에 함유되어 있는 염의 제거 거동을 살펴보는 것이다. 계면중합법으로 나노복합막을 제조하고 상용화되어 있는 나노복합막과 탈염 거동을 비교하였다. 세리신 용액은 단백질 분해효소에 의해서 분해하여 저분자화하였고 전기영동에 의해 분자량 분포를 살펴보았다. 상대투과유량을 조사하여 나노복합막의 막오염 정도를 살펴보았다. 기공크기가 큰 나노복합막이 탈염에 효율적인 것을 확인하였다.

• 한국수소및신에너지학회논문집
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• 제18권2호
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• pp.151-156
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• 2007

Solar cell and nanofiltration membrane were utilized in a system of enzymatic hydrogen production through light-sensitized photoanode, which resembles photoelectrochemical(PEC) configuration. Solar cell uses no additional light energy to increase energy for electrons to reduce protons and for holes to oxidize water to oxygen, and nanofiltration membrane replaces a salt bridge successfully with increased ion transport capability. With this system configuration, optimized amount of enzyme(10.98 unit), and an anodized tubular $TiO_2$ electrode($5^{\circ}C$/1 hr in 0.5 wt% HF-$650^{\circ}C$/5 hr) hydrogen evolved at a rate of ca. $43\;{\mu}mol/(cm^2{\times}hr)$ in a cathodic compartment and oxygen generated at a rate of ca. $20\;{\mu}mol/(cm^2{\times}hr)$ in an anodic compartment. The stoichiometric evolution of gases indicated that water was splitted in the system.

• 멤브레인
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• 제12권3호
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• pp.165-170
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• 2002

씻어나온 쌀(무세미) 생산공정 중 발생하는 쌀뜨물 중 함유된 유효성분, 특히 단백질 회수를 위한 분리막 공정에 관하여 검토하였다. 먼저 dead-end형 Amicon 여과셀을 이용하여 단백질 농축에 적절한 분리막을 선정하였으며 이를 토대로 중공사형 한외여과 모듈 또는 가정용 정수기에 사용되는 나권형 나노여과 및 역삼투 모듈을 이용한 투과실험을 행하였다. 그 결과, 분획분자량이 10,000 dalton인 한외여과막은 쌀뜨물내 유효성분 내지는 단백q질을 농축하기에 적절하지 않았다. 그러나 역삼투 또는 나노여과 모듈에 9% 가량의 단백질이 함유된 원료용액을 250%까지 농축할 경우, 역삼투 모듈 농축액중에 단백질의 농도는 22%로서 약 2.4배가 농축되었으며 나노여과 모듈의 경우는 약 2배까지 단백질을 농축할 수 있었다.

• 상하수도학회지
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• 제18권2호
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• pp.165-173
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• 2004

Behavior of hazardous organic compounds including bisphenol A, phtalic acid, and phosphoric acid in low pressure nanofiltration process were investigated. In the case of NTR729HF, rejection of all target organic compounds except 2-H-Benzothiazol and 2-isopropyl phenol was more than 90%. The lowest rejection for 2-H-Benzothiazol was observed in another membranes. The UTC60 and UTC20 showed similar rejection characteristics of hazardous organic compounds. Although the rejection of Bisphenol A, n-buthyl benzenesulfoneamide, N-ethyl-p-toluensulfonamide, 2-H-benzothiazol, p-t-butylphenol and 2-isopropyl phenol was less than 30%, the rejection of tributyl phosphate, triethyl phosphate, camphor, 2,2,4 trimethyl 1,3 pentandiol and diphenyl amine was more than 90% in the case of UTC60 and UTC20. The rejection characteristics of various hazardous organic compounds were converted into one parameter Ks, which was proposed in the diffusion-convection model. The Ks of hazardous organic compounds were discussed by comparing with their solute size represented by Stokes radius. The diffusion convection model considering Ks was successful to interpret rejection characteristics of hazardous organic compounds by low-pressure nanofiltration membranes.

• Membrane and Water Treatment
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• 제6권3호
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• pp.173-187
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• 2015

The goal of present work is the preparation of a novel positively charged nanofiltration (NF) membrane and its development for the cation removal of aqueous solutions. This NF membrane was fabricated by the surface modification of polysulfone (PSf) ultrafiltration support. The active top-layer was formed by interfacial cross-linking polymerization of poly(ethyleneimine) (PEI) with p-xylylene dichloride (XDC) and then quaternized with methyl iodide to form a perpetually positively charged layer. In order to improve the efficiency of nanofiltration membrane, the concentration of PEI, XDC and methyl iodide solutions, PEI coating and cross-linking time have been optimized. As a result, a high water flux and high $CaCl_2$ rejection (1,000 ppm) was obtained for the composite membrane with values of $18.29L/m^2.h$ and 93.62% at 4 bar and $25^{\circ}C$, respectively. The rejections of NF membrane for different salt solutions followed the order of $Na_2SO_4$ < $MgSO_4$ < NaCl < $CaCl_2$. Molecular weight of cut off (MWCO) was calculated via retaining of PEG solutions with different molecular weights that finally, it revealed the Stokes and hydrodynamic radius of 1.457 and 2.507 nm on the membrane selective layer, respectively. The most efficient positively charged nanofiltration membrane exhibited a $Ni^{2+}$ rejection of 96.26% for industrial wastewater from Shamse Hadaf Co. (Kashan, Iran).

• Membrane and Water Treatment
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• 제10권3호
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• pp.239-244
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• 2019

Plating wastewater containing various heavy metals can be produced by several industries. Specifically, we focused on the removal of copper (Cu2+) and nickel (Ni+) ions from the plating wastewater because all these ions are strictly regulated when discharged into watershed in Korea. The application of both nanofiltration (NF) and reverse osmosis (RO) technologies for the treatment of wastewater containing copper and nickel ions to reduce fresh water consumption and environmental degradation was investigated. In this work, the removal of copper (Cu2+) and nickel (Ni+) ions from synthetic water was studied on pilot scale remove by before using two commercial nanofiltration (NF) and reverse osmosis(RO) spiral-wound membrane modules (NE2521-90 and RE2521-FEN by Toray Chemical). The influence of main operating parameters such as feed concentration on the heavy metals rejection and permeate flux of both membranes, was investigated. Synthetic plating wastewater samples containing copper ($Cu^{2+}$) and nickel ($Ni^{2+}$) ions at various concentrations(1, 20, 100, 400 mg/L) were prepared and subjected to treatment by NF and RO in the pilot plant. The results showed that NF, RO process, with 98% and 99% removal for copper and nickel, respectively, could achieve high removal efficiency of the heavy metals.

• Membrane and Water Treatment
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• 제13권2호
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• pp.105-110
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• 2022

Al₂O₃ positively charged nanofiltration composite membrane was successfully prepared with aluminate coupling agent (ACA) as modifier, sodium bisulfite (NaHSO₃) and potassium persulfate (K₂S₂O₈) as initiator and methacryloyloxyethyl trimethylammonium chloride (DMC) as crosslinking monomer. The surface of the membrane before grafting and after polymerization were characterized by SEM and FT-IR. Three factor and three-level orthogonal experiments were designed to explore the optimal conditions for membrane preparation, and the optimal group was successfully prepared. The filtration experiments of different salt solutions were carried out, and the retention molecular weight was determined by polyethylene glycol (PEG). The results showed that the polymerization temperature had the greatest effect on the rejection rate, followed by the reaction time, and the concentration of DMC had the least effect on the rejection rate. The rejection rates of CaCl₂, MgSO₄, NaCl and Na₂SO₄ in the optimal group were 83.8%, 81.3%, 28.1% and 23.6% (average value), respectively. The molecule weight cut-off of 90% (MWCO) of the optimal group was about 460, which belongs to nanofiltration membrane.

• Membrane and Water Treatment
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• 제7권4호
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• pp.327-339
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• 2016

Nanofiltration is useful to concentrate propolis extract. During the selection of membrane, both compound rejection and permeate flux are important indicators of process economy. Brazilian green propolis extract was studied to evaluate the separation performance of Startmen 122 and NF270 membranes. Compared to Starmen 122, NF270 membrane showed better rejection of bioactive compounds. The flux decline patterns were further studied using Hermia's model. Cake formation is the major fouling mechanism on the hydrophobic surface of Starmen 122. While the fouling mechanism for NF270 is pore blocking. The fouled membranes were further characterized using SEM and FT-IR to confirm on the predicted fouling mechanisms.

• Membrane and Water Treatment
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• 제2권1호
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• pp.63-74
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• 2011

A spiral wound nanofiltration (NF) membrane (GE Osmonics, DK 4040F) was used to remove pesticides from water. Several solutions of single pesticides and their mixtures were prepared. The pesticides initial concentration ranged from ca. 50 ng/L (single pesticide) to ca. 700 ng/L (as sum of 14 pesticides) and progressively increased with time since the NF experiments were carried out in a concentration mode up to a Volume Concentration Ratio, VCR = 10. Permeate flux and pesticides retention were evaluated as a function of the Volume Concentration Ratio. The permeate flux did not practically change by varying VCR. Pesticide retention was found to be around 97-98% both in the cases of single pesticide solutions and different mixtures of pollutants, and was not affected by the VCR. Pesticides concentration in permeate samples was found to be lower than the maximum concentration level fixed in European directive.