scholarly journals Engineered polyethersulfone membrane for well-dispersed silver nanoparticle impregnation at high loading: high water permeate flux and biofouling prevention

Author(s):  
Mohana Mukherjee ◽  
Rajdip Bandyopadhyaya

Abstract We present a new method for impregnation of silver nanoparticles (Ag NPs) at high loading on PES membrane's external surface, simultaneously retaining native membrane's porosity – to achieve a high water permeate flux without biofouling. This was possible by PES membrane's surface modification with acrylic acid (AA), finally leading to AA-Ag-PES membrane. AA-Ag-PES had a high (9.04%) Ag-NP loading selectively on membrane surface, as discrete, smaller (mean size: 20 nm) NPs. In nonfunctionalized Ag-PES, aggregated (mean size: 70 nm) NPs, with lower Ag loading (0.73 wt.%) was obtained, with NP being present both on membrane surface and inside pores. Consequently, AA-Ag-PES could maintain similar water permeability and porosity (10,153.05 Lm−2 h−1bar−1 and 69.98%, respectively), as in native PES (11,368.74 Lm−2 h−1bar−1 and 68.86%, respectively); whereas both parameters dropped significantly for Ag-PES (4,869.66 Lm−2 h−1bar−1 and 49.02%, respectively). AA-Ag-PES also showed least flux reduction (7.7%) due to its anti-biofouling property and high flux recovery after usage and cleaning, compared to native PES and Ag-PES membrane's much higher flux reduction (54.29% and 36.7%, respectively). Hence, discrete NP impregnation, avoiding pore blockage, is key for achieving high water flux and anti-biofouling properties (in AA-Ag-PES), compared to non-functionalized Ag-PES, due to aggregated Ag-NPs inside its pores.

Author(s):  
N. Chin ◽  
S. O. Lai ◽  
K. C. Chong ◽  
S. S. Lee ◽  
C. H. Koo ◽  
...  

The study was concerned with the treatment of tank dewatering produced water using hybrid microfiltration (MF) and ultrafiltration (UF) processes. The pre-treatment MF membrane was fabricated with polyethersulfone (PES), n-methyl-2-pyrrolidone (NMP) and polyvinylpyrrolidone (PVP). The UF membranes meanwhile contained additional component, i.e., titanium dioxide (TiO2) nanoparticles in the range of zero to 1.0 wt.%. The membrane performances were analysed with respect to permeate flux, oil removal and flux recovery ratio. An increase in TiO2 nanoparticles enhanced the pore formation, porosity and pure water permeability due to improved hydrophilicity. The permeate flux of UF membranes increased with the increase of TiO2 nanoparticles and pressure. The oil removal rate by MF process was only 52.35%, whereas the oil rejection efficiency was between 82.34% and 95.71% for UF process. It should be highlighted that the overall oil removal rate could achieve as high as 97.96%. Based on the results, the PES membrane incorporated with 1.0 wt.% TiO2 was proved to be the most promising membrane at a transmembrane pressure of 3 bar. Although 1.0 M NaOH solution could be used as cleaning agent to recover membrane water flux, it is not capable of achieving good results as only 52.18% recovery rate was obtained.


2018 ◽  
Vol 65 ◽  
pp. 05023 ◽  
Author(s):  
Kok Poh Wai ◽  
Chai Hoon Koo ◽  
Yean Ling Pang ◽  
Woon Chan Chong ◽  
Woei Jye Lau

Silver nanoparticles (NP) was successfully immobilized on polydopamine (PDA) supported polyethersulfone (PES) membrane via a redox reaction. Polyvinylpyrrolidone (PVP) was added into membrane dope solution as a pore-forming agent. Four pieces of membranes (M1, M2, M3 and M4) were fabricated with different active layer coatings to compare their morphological and performance properties. The differences between each sample were highlighted as follow: M1 (pristine PES), M2 (PES+PVP), M3 (PDA/PES+PVP) and M4 (Ag/PDA/PES+PVP). All membranes were characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction and contact angle analysis. The membrane performance was examined using pure water permeability (PWP) test, antibacterial test and humic acid (HA) rejection test. Pristine M1 membrane showed that PWP of 27.16 LMH/bar and HA rejection of 84 %. In this study, it was found that the addition of PVP as a pore agent into the membrane M2 increased water flux but slightly deteriorated HA rejection. Coating of PDA on M3 and immobilizing silver NP on M4 membrane surface have improved HA rejection but compromised PWP. The results showed that membrane M4 carried excellent antibacterial property and highest HA rejection among all fabricated membranes.


2021 ◽  
Vol 45 (1) ◽  
pp. 1-10
Author(s):  
Davood Ghanbari ◽  
Samaneh BandehAli ◽  
Abdolreza Moghadassi

Abstract In this study, three types of ferrites nanoparticles including CoFe2O4, NiFe2O4, and ZnFe2O4 were synthesized by microwave-assisted hydrothermal method. The X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FESEM) were employed to analyze synthesized nanoparticles and fabricated membranes. The morphology of membrane surface was investigated by surface images. The ability of ferrite nanoparticles was evaluated to the separation of sodium salt and heavy metals such as Cr2+, Pb2+, and Cu2+ from aqueous solutions. The modified membrane showed the enhancement of membrane surface hydrophilicity, porosity, and mean pore size. The results revealed a significant increase in pure water flux: 152.27, 178, and 172.68 L·m−2·h−1 for PES/0.001 wt% of CoFe2O4, PES/0.001 wt% NiFe2O4, and PES/0.001 wt% ZnFe2O4 NPs, respectively. Moreover, Na2SO4 rejection was reached 78% at 0.1 wt% of CoFe2O4 NPs. The highest Cr (II) rejection obtained 72% for PES/0.001 wt% of NiFe2O4 NPs while it was 46% for the neat PES membrane. The Pb(II) rejection reached above 75% at 0.1 wt% of CoFe2O4 NPs. The Cu(II) rejection was obtained 75% at 0.1 wt% of CoFe2O4 NPs. The ferrite NPs revealed the high potential of heavy metal removal in the filtration membranes.


Author(s):  
I. N. H. M. Amin ◽  
A. W. Mohammad

Studies were conducted to investigate the blocking mechanism and flux decline behavior while treating organic solutes contained in glycerin-water solutions (triglycerides, TG and fatty acid, FA). Two ultrafiltration membranes were tested, polyethersulphone (PES 25 kDa) and polyvinylidenfluoride (PVDF 30 kDa) membranes. Influence of TG and its combination (TG-FA mixtures) as foulant models, pH of feed solutions (3–10) and membrane surface chemistry were investigated. Combined blocking model was applied and the fitting were discriminate that the flux decline of PES membrane was dominated by pore blockage at the early stage and later by cake resistance during the entire filtration time. However, for PVDF membrane, cake formation mechanism was acknowledged as the major contributor to the fouling mechanism for all the parameters tested. On the other hand, the model predicts there are two stages of filtration appeared to occur, involving pore blockage at the early stage followed by cake formation.


2013 ◽  
Vol 594-595 ◽  
pp. 877-881 ◽  
Author(s):  
Siti Hawa Mohamad ◽  
M.I. Idris ◽  
Hasan Zuhudi Abdullah

This paper focuses on performance of polyethersulfone (PES) ultrafiltration membrane coated with titanium dioxide (TiO2) nanoparticles and irradiated with UV light. The flat sheet membrane was prepared via phase inversion method, with two types of membrane; TiO2 coated PES membrane and UV irradiated TiO2 coated PES membrane. TiO2 suspension with concentration of 0.01, 0.03 and 0.05 wt.% were prepared and coated on the PES surface via dip coating. Membrane was immersed in all suspension for 15 minutes and 30 minutes. Then, prepared coated membranes were irradiated by 184 Watts UV lamp for 15 minutes. The performance of membranes was examined by permeation of humic acid. The morphology of membranes was analyzed by scanning electron microscopy (SEM). It was revealed that the pure water flux and humic acid permeation of UV irradiated TiO2 coated membrane was higher than TiO2 coated membrane. It can be concluded that TiO2 coated with 0.03 wt.% of suspension, 30 minutes and 15 minutes UV irradiation with 184 Watt light were determined as the optimum conditions for preparation ultrafiltration PES membrane.


Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 216
Author(s):  
Hazel Lynn C. Maganto ◽  
Micah Belle Marie Yap Ang ◽  
Gian Vincent C. Dizon ◽  
Alvin R. Caparanga ◽  
Ruth R. Aquino ◽  
...  

The advancement in membrane science and technology, particularly in nanofiltration applications, involves the blending of functional nanocomposites into the membranes to improve the membrane property. In this study, Ag-polydopamine (Ag-PDA) particles were synthesized through in situ PDA-mediated reduction of AgNO3 to silver. Infusing Ag-PDA particles into polyethersulfone (PES) matrix affects the membrane property and performance. X-ray photoelectron spectroscopy (XPS) analyses confirmed the presence of Ag-PDA particles on the membrane surface. Field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) describe the morphology of the membranes. At an optimum concentration of Ag-PDA particles (0.3 wt % based on the concentration of PES), the modified membrane exhibited high water flux 13.33 L∙m−2∙h−1 at 4 bar with high rejection for various dyes of >99%. The PESAg-PDA0.3 membrane had a pure water flux more than 5.4 times higher than that of a pristine membrane. Furthermore, in bacterial attachment using Escherichia coli, the modified membrane displayed less bacterial attachment compared with the pristine membrane. Therefore, immobilizing Ag-PDA particles into the PES matrix enhanced the membrane performance and antibacterial property.


Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 141 ◽  
Author(s):  
Hiroki Miyakawa ◽  
Mohammed Maghram Al Shaiae ◽  
Troy N. Green ◽  
Yohito Ito ◽  
Yuichi Sugawara ◽  
...  

For providing advanced desalination the combination of the improvement of water recovery ratio in the reverse osmosis (RO) process and the No-Chlorine/No-Sodium Bisulfite (SBS) Dosing process was studied. In order to prevent membrane fouling even in high recovery water operations, an advanced two-stage design was implemented to (1) control the permeate flux through the RO membrane module, (2) optimize the system to reduce contaminant build-up and (3) eliminate the use of chlorine and SBS, which can accelerate membrane fouling. The system was evaluated by monitoring the biofouling and the microorganisms proliferation on the membrane surface based on membrane biofilm formation rate (mBFR). The pilot plant was operated in the condition of a water recovery rate of 55%. As a result, the system was operated for longer than four months without membrane cleaning (clean in place; CIP) and the possibility of operation for seven months without CIP was confirmed by the extrapolation of the pressure values. In addition, the mBFR is a reliable tool for water quality assessment, based on a comparison between the fouling tendency estimated from the mBFR and the actual membrane surface condition from autopsy study and the effectiveness No-Chlorine/No-SBS Dosing process was verified from mBFR of pretreated seawater.


Membranes ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 21 ◽  
Author(s):  
Chunyan Ma ◽  
Chao Yi ◽  
Fang Li ◽  
Chensi Shen ◽  
Zhiwei Wang ◽  
...  

Membrane fouling is the bottleneck limiting the wide application of membrane processes. Herein, we adopted an electroactive polyether sulfone (PES) membrane capable of mitigating fouling by various negatively charged foulants. To evaluate anti-fouling performance and the underlying mechanism of this electroactive PES membrane, three types of model foulants were selected rationally (e.g., bovine serum albumin (BSA) and sodium alginate (SA) as non-migratory foulants, yeast as a proliferative foulant and emulsified oil as a spreadable foulant). Water flux and total organic carbon (TOC) removal efficiency in the filtering process of various foulants were tested under an electric field. Results suggest that under electrochemical assistance, the electroactive PES membrane has an enhanced anti-fouling efficacy. Furthermore, a low electrical field was also effective in mitigating the membrane fouling caused by a mixture of various foulants (containing BSA, SA, yeast and emulsified oil). This result can be attributed to the presence of electrostatic repulsion, which keeps foulants away from the membrane surface. Thereby it hinders the formation of a cake layer and mitigates membrane pore blocking. This work implies that an electrochemical control might provide a promising way to mitigate membrane fouling.


2020 ◽  
Vol 10 (3) ◽  
pp. 187-199
Author(s):  
Mohd Azwan Ahmad ◽  
Bidattul Syirat Zainal ◽  
Nashrah Hani Jamadon ◽  
Thomas Choong Shean Yaw ◽  
Luqman Chuah Abdullah

Abstract Palm oil mill effluent (POME) is a hazardous wastewater which contains high organic constituents and salt concentrations. The ultrafiltration (UF) process is a promising treatment design used for secondary treatment such as POME. However, membrane fouling is the major problem which limits the performance of the UF. This paper describes a detailed investigation of polyvinylidiene fluoride (PVDF) membrane for the treatment of POME. The fouling behavior was analyzed by water flux, fouling mechanism, scanning electron microscopy (SEM), particle size distribution (PSD) and Energy Dispersive X-ray (EDX). It was found that a significant reduction in the permeate flux was caused by the build up of a fouling layer. Study on the fouling mechanism shows that cake filtration dominated the fouling activities on the membrane surface, compared to standard blocking, intermediate blocking, and complete blocking. This result is supported by membrane autopsy through SEM, PSD and EDX.


2014 ◽  
Vol 69 (9) ◽  
Author(s):  
C. S. Ong ◽  
W. J. Lau ◽  
P. S. Goh ◽  
A. F. Ismail Ismail

Polyvinylidene fluoride (PVDF) hollow fiber ultrafiltration (UF) membranes consisted of TiO2 and different molecular weight (Mw) of polyvinylpyrrolidone (PVP) (i.e. 10, 24, 40 and 360 kDa) were prepared to treat synthesized oily wastewater. The membrane performances were characterized in terms of pure water flux, permeate flux and oil rejection while the membrane morphological properties were studied using SEM and AFM. PVDF-TiO2 composite membrane prepared from PVP40k was found as the optimum membrane due to its high flux and high rejection during filtration process, recording      45 L/m2.h and 80% respectively, when tested using 250 ppm oily solution under submerged condition. The experimental results demonstrated that with increasing Mw of PVP, PVDF-TiO2 membrane had higher protein rejection, smaller porosity and smoother surface layer. With increasing oil concentration from 250 to 1000 ppm, the permeate flux of the PVDF-PVP40k was obviously decreased while the oil rejection was gradually increased due to the additional selective layer formed on the membrane surface.  Based on the findings, the PVDF-TiO2 membrane with PVP40k can be considered as a potential membrane for oily wastewater industry due to the high permeate flux and oil rejection. 


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