Sodium Chloroacetate Modified Polyethyleneimine/Trimesic Acid Nanofiltration Membrane to Improve Antifouling Performance

Nanofiltration (NF) is a separation technology with broad application prospects. Membrane fouling is an important bottleneck-restricting technology development. In the past, we prepared a positively charged polyethyleneimine/trimesic acid (PEI/TMA) NF membrane with excellent performance. Inevitably, it also faces poor resistance to protein contamination. Improving the antifouling ability of the PEI/TMA membrane can be achieved by considering the hydrophilicity and chargeability of the membrane surface. In this work, sodium chloroacetate (ClCH2COONa) is used as a modifier and is grafted onto the membrane surface. Additionally, 0.5% ClCH2COONa and 10 h modification time are the best conditions. Compared with the original membrane (M0, 17.2 L m−2 h−1), the initial flux of the modified membrane (M0-e, 30 L m−2 h−1) was effectively increased. After filtering the bovine albumin (BSA) solution, the original membrane flux dropped by 47% and the modified membrane dropped by 6.2%. The modification greatly improved the antipollution performance of the PEI/TMA membrane.

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Water Permeates in Ceramic Membrane Modified with Nano Inorganic Coating

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.239-242.27 ◽

2011 ◽

Vol 239-242 ◽

pp. 27-30

Author(s):

Jian Er Zhou ◽

Qi Bing Chang ◽

Ying Chao Dong ◽

Xue Bing Hu ◽

Yong Qing Wang ◽

...

Keyword(s):

Membrane Fouling ◽

Ceramic Membrane ◽

Membrane Surface ◽

Molecular Layer ◽

Pore Wall ◽

Boundary Slip ◽

Membrane Pore ◽

Nano Coating ◽

Inorganic Coating ◽

Modified Membrane

Membrane surface modification is the important method to decrease membrane fouling. The hydrophilic modification of ceramic membrane with nano-sized inorganic coating is prepared by the wet chemical methods. The thin nano coating is not a separating top layer but distributes uniformly on the surface of the membrane pore wall. The coating does not change the structure of the membrane pores. Therefore, water flows on not the pore wall but the nano coating surface. The results show that the water flux of the modified membrane is higher than that of the unmodified membrane despite that the mean pore size of the modified membrane decreases. The “boundary slip” is used to explain this special phenomenon. What generates the slippage? The slippage is relative with the molecular layer adhered tightly on the hydrophilic pore wall, the roughness and the surface charge of the nano coating, the interaction between the ions in water and the nano coating, et al.

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Study on Membrane Fouling Experiment of Stacked AGMD Module in Low Temperature

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.396-398.458 ◽

2011 ◽

Vol 396-398 ◽

pp. 458-462

Author(s):

Xiao Hong Yang ◽

Rui Tian ◽

Shu Juan Ma ◽

Hai Li Lv

Keyword(s):

Membrane Fouling ◽

Tap Water ◽

Membrane Surface ◽

Membrane Distillation ◽

Thermal Mass ◽

Initial Value ◽

Air Gap Membrane Distillation ◽

Membrane Flux ◽

Before And After ◽

New Type

In this paper, it has studied membrane fouling experiments at a certain temperature conditions and with untreated tap water as thermal mass, which applied unique multi-layered stacked air-gap membrane distillation module. It has analyzed the original membrane flux and conductivity changes in the experiments, and carried out SEM and EDS analysis before and after acid washed fouling membrane. The results show that: New type membrane module will produce fouling even at lower temperatures. Membrane surface was covered by a lot of uneven accumulation granular pollutants and cuboid crystals, so the mass flux reduced. Fouling membrane washed with 5 % hydrochloric acid solution was removed inorganic scale. The flux recovered to the initial value.

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Recycling of spent filter backwash water using coagulation-assisted membrane filtration: effects of submicrometre particles on membrane flux

Water Science & Technology ◽

10.2166/wst.2010.146 ◽

2010 ◽

Vol 61 (8) ◽

pp. 1923-1929 ◽

Cited By ~ 7

Author(s):

Chihpin Huang ◽

Jr-Lin Lin ◽

C. L. Wu ◽

C. P. Chu

Keyword(s):

Particle Size ◽

Fractal Dimension ◽

Zeta Potential ◽

Pore Size ◽

Membrane Fouling ◽

Membrane Filtration ◽

Membrane Surface ◽

Treatment Plant ◽

Membrane Flux ◽

Filter Backwash Water

Membrane separation technology has been widely used for recycling of spent filter backwash water (SFBW) in water treatment plant. Membrane filtration performance is subject to characteristics of the particles in the SFBW. A bench-scale microfiltration (MF) coupled with pre-coagulation was set up to evaluate the recovery efficiency of SFBW. Effect of particle size distribution and zeta potential of the coagulated SFBW on the membrane filtration as well as the coagulation strategies were investigated. Pore clogging was more severe on the membrane with 1.0 μm pore size than on the membrane with 0.5 μm pore size due to the fact that submicrometre particles are dominant and their diameters are exactly closed to the pore size of the MF membrane. Pre-settling induced more severe irreversible fouling because only the submicrometre particles in the water become predominant after settling, resulting in the occurrence of more acute pore blocking of membrane. By contrast, pre-coagulation mitigates membrane fouling and improves membrane flux via enlarging particle size on membrane surface. The variations of zeta potential in response to coagulant dosing as well as fractal dimension were also compared with the performance of the subsequent filtration. The result showed that pre-coagulation induced by charge neutralization at the optimum dosage where the zeta potential is around zero leads to the optimal performance of the subsequent membrane filtration for SFBW recycling. At such condition, the fractal dimension of coagulated flocs reached minimum.

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Study of Backwashing Process for Ceramic Micro-Filtration Membranes Used in Pretreatment of DMF Wastewater

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.418-420.1980 ◽

2011 ◽

Vol 418-420 ◽

pp. 1980-1983

Author(s):

Peng Wei Xu ◽

Wei Qiu Huang ◽

Qi Zhang ◽

Bao Zhu Yang ◽

Jing Zhong

Keyword(s):

Membrane Fouling ◽

Reverse Flow ◽

Average Pore Size ◽

Membrane Surface ◽

Permeate Flux ◽

Average Pore ◽

Filtration Membranes ◽

Membrane Flux ◽

In Series ◽

Flow Through

DMF wastewater from the PU synthetic leather industries was filtrated by ZrO2 micro-filtration membranes with an average pore size of 0.2μm. The membrane fouling mechanism was analyzed by resistance-in series model. The results indicated that the resistance from the particles sedimentation on membrane surface accounting for 76% of the total resistances. The technology of backwashing was a stable, valid and reusable method to recover the membrane flux in the micro-filtration. During backwashing, the reverse flow through the membrane removes the concentration polarization and cake or gel layers from the membrane surface. The effect of the backwashing conditions on the flux was studied. The obtained optimization conditions were as follows: backwashing pressure 0.6 MPa, backwashing time 5s and the backwashing interval 20min. The permeate flux could be raised about 50% compared with that without backwashing.

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The Effect of Different Pretreatment Methods on the Membrane Fouling in the Process of Reverse Osmosis Seawater Desalination

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.821-822.1102 ◽

2013 ◽

Vol 821-822 ◽

pp. 1102-1109 ◽

Cited By ~ 1

Author(s):

Jian Gao Cheng ◽

Jing Huan Ma ◽

Zhi Wen Lin ◽

Wei Xing Li ◽

Zhan Sheng Ma ◽

...

Keyword(s):

Reverse Osmosis ◽

Membrane Fouling ◽

Membrane Surface ◽

Reverse Osmosis Membrane ◽

Seawater Desalination ◽

Membrane Flux ◽

Attenuation Rate ◽

Ultra Filtration ◽

The One

One new pretreatment method was developed for solving the formed fouling on the equipments in the process of reverse osmosis seawater desalination, and the effect of different pretreatment methods on the membrane fouling was investigated. The experiment results showed that the flux attenuation rate of reverse osmosis membrane used in hardness-removed seawater was slower than the one of direct ultrafiltration seawater, and the salt reject rate and conductivity of output water from reverse osmosis membrane were not obviously affected by these two different pretreatment methods respectively. By according to the characterization of SEM, EDX and IR, the rapid attenuation of membrane flux was caused by the piled inorganic crystals on the membrane surface in direct ultra-filtration process, and the hardness-removed pretreatment process can effectively decrease the membrane fouling.

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Nano-Sized Metal Oxide Modification Applied in Microfiltration Membrane Technology

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.68.145 ◽

2010 ◽

Vol 68 ◽

pp. 145-152 ◽

Cited By ~ 1

Author(s):

Jian Er Zhou ◽

Qi Bing Chang ◽

Yong Qing Wang

Keyword(s):

Metal Oxide ◽

Membrane Fouling ◽

Ceramic Membrane ◽

Membrane Surface ◽

Membrane Technology ◽

Future Research ◽

Membrane Pore ◽

Nano Coating ◽

Inorganic Coating ◽

Modified Membrane

Membrane surface modification is the important method to decrease membrane fouling. Recent efforts have been made to develop the hydrophilic modified ceramic membrane with nano-sized inorganic coating in our research group. In the modified membrane, the nano coating does not form a separating layer, just distributes uniformly on the surface of the membrane pore wall. It results in that: (1) if the feed is water, the water flux of the modified membrane is higher than that of the unmodified one despite the fact that the mean membrane pore size decreases after the modification; (2) if the feed is oily emulsion, the steady flux is obtained in a short time and keeps in the following time. The flux is far higher than that of the unmodified one because the hydrophilic nano coating prevents the cake from forming on the membrane surface. The nano-sized metal oxide modification application in the membrane technology not only expands the newly research area of the membrane technology but also makes the modified ceramic membrane have a good perspective application in the industry. This paper will introduce the development of the modified membrane with nano inorganic coating and give a clear future research direction.

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Coagulation/flocculation/ultrafiltration for natural organic matter removal in drinking water production

Water Science & Technology Water Supply ◽

10.2166/ws.2004.0111 ◽

2004 ◽

Vol 4 (5-6) ◽

pp. 215-222 ◽

Cited By ~ 2

Author(s):

A.R. Costa ◽

M.N. de Pinho

Keyword(s):

Drinking Water ◽

Organic Matter ◽

Natural Organic Matter ◽

Membrane Fouling ◽

Membrane Filtration ◽

Membrane Surface ◽

Water Production ◽

Cellulose Acetate Membranes ◽

Wide Range ◽

Drinking Water Production

Membrane fouling by natural organic matter (NOM), namely by humic substances (HS), is a major problem in water treatment for drinking water production using membrane processes. Membrane fouling is dependent on membrane morphology like pore size and on water characteristics namely NOM nature. This work addresses the evaluation of the efficiency of ultrafiltration (UF) and Coagulation/Flocculation/UF performance in terms of permeation fluxes and HS removal, of the water from Tagus River (Valada). The operation of coagulation with chitosan was evaluated as a pretreatment for minimization of membrane fouling. UF experiments were carried out in flat cells of 13.2×10−4 m2 of membrane surface area and at transmembrane pressures from 1 to 4 bar. Five cellulose acetate membranes were laboratory made to cover a wide range of molecular weight cut-off (MWCO): 2,300, 11,000, 28,000, 60,000 and 75,000 Da. Severe fouling is observed for the membranes with the highest cut-off. In the permeation experiments of raw water, coagulation prior to membrane filtration led to a significant improvement of the permeation performance of the membranes with the highest MWCO due to the particles and colloidal matter removal.

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Engineered Nanoparticles with Decoupled Photocatalysis and Wettability for Membrane-Based Desalination and Separation of Oil-Saline Water Mixtures

Nanomaterials ◽

10.3390/nano11061397 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1397

Author(s):

Bishwash Shrestha ◽

Mohammadamin Ezazi ◽

Gibum Kwon

Keyword(s):

Membrane Fouling ◽

Municipal Wastewater ◽

Uv Light ◽

Saline Water ◽

Membrane Surface ◽

Sio2 Nanoparticles ◽

Engineered Nanoparticles ◽

Water Mixture ◽

Organic Substances ◽

Suspended Substances

Membrane-based separation technologies are the cornerstone of remediating unconventional water sources, including brackish and industrial or municipal wastewater, as they are relatively energy-efficient and versatile. However, membrane fouling by dissolved and suspended substances in the feed stream remains a primary challenge that currently prevents these membranes from being used in real practices. Thus, we directly address this challenge by applying a superhydrophilic and oleophobic coating to a commercial membrane surface which can be utilized to separate and desalinate an oil and saline water mixture, in addition to photocatalytically degrading the organic substances. We fabricated the photocatalytic membrane by coating a commercial membrane with an ultraviolet (UV) light-curable adhesive. Then, we sprayed it with a mixture of photocatalytic nitrogen-doped titania (N-TiO2) and perfluoro silane-grafted silica (F-SiO2) nanoparticles. The membrane was placed under a UV light, which resulted in a chemically heterogeneous surface with intercalating high and low surface energy regions (i.e., N-TiO2 and F-SiO2, respectively) that were securely bound to the commercial membrane surface. We demonstrated that the coated membrane could be utilized for continuous separation and desalination of an oil–saline water mixture and for simultaneous photocatalytic degradation of the organic substances adsorbed on the membrane surface upon visible light irradiation.

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Pilot Study on the Combination of Different Pre-Treatments with Nanofiltration for Efficiently Restraining Membrane Fouling While Providing High-Quality Drinking Water

Membranes ◽

10.3390/membranes11060380 ◽

2021 ◽

Vol 11 (6) ◽

pp. 380

Author(s):

Yan Chen ◽

Huiping Li ◽

Weihai Pang ◽

Baiqin Zhou ◽

Tian Li ◽

...

Keyword(s):

Drinking Water ◽

Activated Carbon ◽

Membrane Fouling ◽

Membrane Surface ◽

Post Treatment ◽

Size Exclusion ◽

Transmembrane Pressure ◽

Feed Water ◽

High Quality ◽

Treated Water

Nanofiltration (NF) is a promising post-treatment technology for providing high-quality drinking water. However, membrane fouling remains a challenge to long-term NF in providing high-quality drinking water. Herein, we found that coupling pre-treatments (sand filtration (SF) and ozone–biological activated carbon (O3-BAC)) and NF is a potent tactic against membrane fouling while achieving high-quality drinking water. The pilot results showed that using SF+O3-BAC pre-treated water as the feed water resulted in a lower but a slowly rising transmembrane pressure (TMP) in NF post-treatment, whereas an opposite observation was found when using SF pre-treated water as the feed water. High-performance size-exclusion chromatography (HPSEC) and three-dimensional excitation–emission matrix (3D-EEM) fluorescence spectroscopy determined that the O3-BAC process changed the characteristic of dissolved organic matter (DOM), probably by removing the DOM of lower apparent molecular weight (LMW) and decreasing the biodegradability of water. Moreover, amino acids and tyrosine-like substances which were significantly related to medium and small molecule organics were found as the key foulants to membrane fouling. In addition, the accumulation of powdered activated carbon in O3-BAC pre-treated water on the membrane surface could be the key reason protecting the NF membrane from fouling.

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ZnO Microfiltration Membranes for Desalination by a Vacuum Flow-Through Evaporation Method

Membranes ◽

10.3390/membranes9120156 ◽

2019 ◽

Vol 9 (12) ◽

pp. 156 ◽

Cited By ~ 1

Author(s):

Shailesh Dangwal ◽

Ruochen Liu ◽

Lyndon D. Bastatas ◽

Elena Echeverria ◽

Chengqian Huang ◽

...

Keyword(s):

Membrane Fouling ◽

Membrane Surface ◽

Water Flux ◽

Atomic Layer ◽

Rejection Rate ◽

Contact Angles ◽

Transfer Resistance ◽

Membrane Pore ◽

Evaporation Method ◽

Flow Through

ZnO was deposited on macroporous α-alumina membranes via atomic layer deposition (ALD) to improve water flux by increasing their hydrophilicity and reducing mass transfer resistance through membrane pore channels. The deposition of ZnO was systemically performed for 4–128 cycles of ALD at 170 °C. Analysis of membrane surface by contact angles (CA) measurements revealed that the hydrophilicity of the ZnO ALD membrane was enhanced with increasing the number of ALD cycles. It was observed that a vacuum-assisted ‘flow-through’ evaporation method had significantly higher efficacy in comparison to conventional desalination methods. By using the vacuum-assisted ‘flow-through’ technique, the water flux of the ZnO ALD membrane (~170 L m−2 h−1) was obtained, which is higher than uncoated pristine membranes (92 L m−2 h−1). It was also found that ZnO ALD membranes substantially improved water flux while keeping excellent salt rejection rate (>99.9%). Ultrasonic membrane cleaning had considerable effect on reducing the membrane fouling.

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