scholarly journals Azo dye removal via surfactant-assisted polyvinylidene fluoride membrane

2021 ◽  
Vol 8 (1) ◽  
pp. 25-32
Author(s):  
Fatemeh Darbandi ◽  
Azadeh Mousavi ◽  
Tayebe Bagheri Lotfabad ◽  
Amir Heydarinasab ◽  
Soheila Yaghmaei
Keyword(s):  
Removal Efficiency ◽  
Azo Dye ◽  
Polyvinylidene Fluoride ◽  
Dye Removal ◽  
Tween 80 ◽  
Contact Angles ◽  
Synthetic Dyes ◽  
Permeate Flux ◽  
Pvdf Membrane ◽  
Tween 60

Background: Recently, concerns have been raised regarding the environmental and public health safety of azo dyes, the most widely used synthetic dyes. The membrane technique has been introduced as one of the efficient methods for dye removal treatments. Polyvinylidene fluoride (PVDF) membrane manipulated by surfactants was studied for removal of the azo dye, carmoisine. Methods: PVDF membrane was prepared via non-solvent-induced phase separation (NIPS) and used to remove the azo dye, carmoisine. Three nonionic surfactants including Tween 20, Tween 60, and Tween 80 were used individually as additives in casting solutions to improve PVDF membrane properties. Results: Fourier-transform infrared spectroscopy (FTIR) demonstrated the presence of functional groups of carbonyl (C=O) and hydroxyl (OH), assigned to Tween molecules, in the membrane chemical structure. All Tween species caused a decrease in the surface hydrophobicity of PVDF membranes illustrated by the reduced contact angles. Each Tween at a 2% concentration in the dope solution led to an increase in the pore-size of PVDF membranes, which was estimated by scanning electron microscopy (SEM). However, this impact was reversed at Tween concentrations of 4%. Membranes were assessed for dye removal efficiency and permeate flux in a cross-flow system. Permeability of PVDF membranes improved (~78%) with adding Tween 80 at a concentration of 2%. Tween 60 at a 2% concentration resulted in a ~45% increase in dye removal efficiency of PVDF membranes. And, atomic force microscopy (AFM) showed that Tween 60 increased membrane surface roughness. Conclusion: Surfactant-mediated changes in the surface properties of PVDF membrane improved dye removal efficacy.

scholarly journals Characterization of the Initial Fouling Layer on the Membrane Surface in a Membrane Bioreactor: Effects of Permeation Drag

Membranes ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 121
Author(s):  
Shengli Wang ◽  
Xin Lu ◽  
Lanhe Zhang ◽  
Jingbo Guo ◽  
Haifeng Zhang
Keyword(s):  
Zeta Potential ◽  
Electron Donor ◽  
Energy Barrier ◽  
Polyvinylidene Fluoride ◽  
Membrane Bioreactor ◽  
Membrane Surface ◽  
Permeate Flux ◽  
Pvdf Membrane ◽  
Operating Modes

In this study, the properties of the initial fouling layer on the membrane surface of a bioreactor were investigated under different operating modes (with or without permeate flux) to improve the understanding of the effect of permeation drag on the formation of the initial fouling layer. It was found that protein was the major component in the two types of initial fouling layers, and that the permeation drag enhanced the tryptophan protein-like substances. The attraction of the initial foulants to the polyvinylidene fluoride (PVDF) membrane was ascribed to the high zeta potential and electron donor component (γ−) of the membrane. Thermodynamic analyses showed that the permeation drag-induced fouling layer possessed high hydrophobicity and low γ−. Due to permeation drag, a portion of the foulants overcame an energy barrier before they contacted the membrane surface, which itself possessed a higher fouling propensity. A declining trend of the cohesive strength among the foulants was found with the increasing development of both fouling layers.

scholarly journals Synthesis, characterization and filtration performance of the polyvinylidene fluoride membrane modified by poly(methyl ethacrylate-co-2-acrylamido-2-methylpropane sulfonic acid)

2018 ◽  
Vol 19 (4) ◽  
pp. 1279-1285
Author(s):  
Q. Y. Zhang ◽  
Q. An ◽  
Y. G. Guo ◽  
J. Zhang ◽  
K. Y. Zhao
Keyword(s):  
Sulfonic Acid ◽  
Polyvinylidene Fluoride ◽  
Phase Inversion ◽  
Pure Water ◽  
Water Flux ◽  
Contact Angles ◽  
Fouling Resistance ◽  
Inversion Process ◽  
Pvdf Membrane ◽  
Pure Water Flux

Abstract To enhance the anti-fouling and separating properties of polyvinylidene fluoride (PVDF) membranes, an amphiphilic copolymer of methyl methacrylate and 2-acrylamido-2-methylpropane sulfonic acid, poly(MMA-co-AMPS), was designed and synthesized. Through a phase-inversion process, the poly(MMA-co-AMPS) were fully dispersed in the PVDF membrane. The properties of membrane including the surface and cross-section morphology, surface wettability and fouling resistance under different pH solutions were investigated. Compared to the unmodified PVDF membranes, the contact angles of modified PVDF membranes decreased from 80.6° to 71.6°, and the pure water flux increased from 54 to 71 L·m−2·h−1. In addition, the hybrid PVDF membrane containing 0.5 wt% copolymers demonstrated an larger permeability, better fouling resistance and higher recovery ratio via pure water backlashing, when it was compared with the other blend membranes, and the virgin one in the cyclic test of anti-fouling. The modified membranes with the copolymers possessed an outstanding performance and may be used for further water treatment applications.

Filtration of crude canola oil miscella utilizing PVDF membrane: the effects of pretreatments and operating conditions

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Razieh Niazmand ◽  
Reza Farhoosh ◽  
Seyed Mohammad Ali Razavi
Keyword(s):  
Canola Oil ◽  
Polyvinylidene Fluoride ◽  
Operating Conditions ◽  
Operating Pressure ◽  
Permeate Flux ◽  
Pvdf Membrane ◽  
Flat Membrane ◽  
Temperature And Pressure ◽  
Increasing Temperature ◽  
Membrane Cell

Abstract This study was conducted on adding chemical agents (aqueous solutions of CaCl2, EDTA and SDS) to crude canola oil miscella before ultrafiltration through polyvinylidene fluoride (PVDF) membrane with MWCO 50 kDa in a magnetically stirred flat membrane cell. Operating conditions including pressures 2-5 bar and temperatures 25-55 °C were employed. Permeate flux of pretreated oil samples exhibited sharp risings with increasing temperature and pressure. Except for the oils pretreated with SDS, the rejection of free fatty acids (FFAs) decreased in all oil samples. Increasing the operating pressure to 4 bar decreased the rejection of FFAs. Pretreatment of the oils with SDS and EDTA resulted in higher amounts of phosphorous rejection, while increasing temperature decreased it. Reduction of color values (L, a, and b) of the oil samples was not considerable through the PVDF membrane.

scholarly journals Membrane distillation crystallization using PVDF membrane incorporated with TiO2 nanoparticles and nanocellulose

2020 ◽  
Vol 20 (5) ◽  
pp. 1629-1642 ◽  
Author(s):  
Hoi-Fang Tan ◽  
Why-Ling Tan ◽  
N. Hamzah ◽  
M. H. K. Ng ◽  
B. S. Ooi ◽  
...  
Keyword(s):  
Pore Size ◽  
Tio2 Nanoparticles ◽  
Polyvinylidene Fluoride ◽  
Phase Inversion ◽  
Membrane Distillation ◽  
Coagulation Bath ◽  
Membrane Thickness ◽  
Permeate Flux ◽  
Sem Images ◽  
Pvdf Membrane

Abstract Polyvinylidene fluoride (PVDF) membrane was improved using TiO2 nanoparticles and nanocellulose for membrane distillation crystallization in this work. Besides the addition of TiO2 nanoparticles and nanocellulose, PVDF membrane was post-modified with octadecyltrichlorosilane after phase inversion using a dual coagulation bath. The addition of hydrophilic TiO2 nanoparticles and nanocellulose reduced membrane hydrophobicity, but the dispersed TiO2 nanoparticles assisted silane modification to improve surface hydrophobicity. Besides reducing the agglomeration of TiO2 nanoparticles, nanocellulose induced the formation of larger pore size and higher porosity as proven in SEM images and gravimetric measurement, respectively. The abundant moieties of nanocellulose accelerated the exchange between solvent and non-solvent during phase inversion for the formation of large pore size and porosity, but membrane thickness increased due to the thickening effects. The modified membrane showed higher water permeate flux in membrane distillation with salt rejection greater than 97%. Severe fouling in membrane distillation crystallization was not observed.

PVDF MEMBRANE FOR OIL-IN-WATER SEPARATION VIA CROSS-FLOW ULTRAFILTRATION PROCESS

2015 ◽  
Vol 78 (1) ◽  
Author(s):  
A. Moslehyani ◽  
M. Mobaraki ◽  
A. F. Ismail ◽  
M. H. D. Othman ◽  
A. Mayahi ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Cross Flow ◽  
Permeate Flux ◽  
Thermal Stabilities ◽  
Water Separation ◽  
Pvdf Membrane ◽  
Membrane Matrix ◽  
Phase Inversion Technique ◽  
Oil In Water ◽  
Wet Phase Inversion

The objective of this study is to investigate the potential of ultrafiltration polyvinylidene fluoride (PVDF)-titanium dioxide (TiO2) membrane for oil-in-water separator. PVDF polymeric matrix membrane is excellent in term of chemical and thermal stabilities, which make it very promising to be used as a membrane matrix for water separation. However, poor hydrophilic property of the PVDF has led to the severe fouling during operation. Thus, current work was performed to investigate the effect of incorporation of two additives i.e. polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) in PVDF-TiO2 membrane, which fabricated using dry/wet phase inversion technique. Membranes characterizations were performed using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), contact angle and UV-vis spectrophotometer. Accordingly, modified PVDF membrane possessed good hydrophilicity property when the additives were added into PVDF-TiO2 membrane matrix. In term of filtration performance, the experimental results showed that oil rejection using PVDF-TiO2/PVP membrane were ~99.7%, which met the requirement for discharge. On the other hand, PVDF-TiO2/PEG membrane was shown more enhancement in terms of permeate flux by given over 64 (L/m2h) at pressure of 2 bar gauge.

scholarly journals Biological decolorization of reactive azo dye by anaerobic/aerobic-sequencing batch reactor system

2015 ◽  
Vol 17 (1) ◽  
pp. 210-219 ◽  
Keyword(s):  
Removal Efficiency ◽  
Azo Dye ◽  
Dye Removal ◽  
Batch Reactor ◽  
Cod Removal ◽  
Organic Loading Rate ◽  
Batch Reactors ◽  
System P ◽  
Removal Efficiencies ◽  
Initial Color

<div> <p>This study aims to investigate the removal of a reactive azo dye (Reactive Red 198) in anaerobic/aerobic sequencing batch reactors (SBR). The total volume of the SBR system used in the study was 10 l. Sludge age was selected as 15 days. The color removal efficiencies varied between 76 to 98% with initial color concentrations of about 20 and 50 mg l<sup>-1</sup>. The effluent color concentration changed between 0.4-6.0 mg l<sup>-1</sup>. The maximum dye removal efficiencies of the SBR system under 20 mg l<sup>-1</sup> dye concentration with 16/4 hours anaerobic/aerobic phases respectively were %98. The increase of anaerobic contact times had improved dye removal efficiency. The COD removal was also high during this period (81-94 %). The increase of organic loading rate from 500 to 1000 mg COD l<sup>-1</sup> day<sup>-1</sup> had improved the dye removal efficiency (from 88% to 96%) but deteriorated the COD removal efficiency to 81% from 88% in SBR systems.</p> </div> <p>&nbsp;</p>

scholarly journals Deduction of Surfactants Effect on Performance, Morphology, Thermal and Molecular Properties of Polymeric Polyvinylidene Fluoride (PVDF) Based Ultrafiltration Membrane

2018 ◽  
Vol 63 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Nurul Hannan Mohd Safari ◽  
Abdul Rahman Hassan ◽  
Che Wan Insyirah Che Wan Takwa ◽  
Sabariah Rozali
Keyword(s):  
Polyvinylidene Fluoride ◽  
Sodium Dodecyl ◽  
Tween 80 ◽  
Permeate Flux ◽  
Cross Sectional ◽  
Membrane Pores ◽  
Surfactant Material ◽  
Uf Membranes ◽  
Pore Properties ◽  
Triton X

In membrane making, surfactant material is one of the effective strategies to produce membrane / thin film with optimal and specific properties. This paper addressed the effect of Sodium dodecyl sulphate (SDS), Triton X-100 and Tween 80 as additives for the making of Polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes. The fabricated membranes were analysed in the aspect of performance, morphological structures, thermal properties and molecular orientation. Analysis results showed that the surfactant additives enhanced the membrane performance and properties. Surprisingly, the addition of 2 wt% surfactant increased the permeate flux of bovine serum albumin (BSA) up to 78.14 L/m2h compared to membrane without surfactant with flux at only 2.74 L/m2h. In addition, the role of surfactants on membrane pores and pore properties of PVDF UF membranes were examined. The cross-sectional morphological structures showed that these surfactants led towards the formation of macro-voids and finger-like structures as well as a spongy layer. The surfactants additives also improved the membrane pores and pore properties which reflect to the protein rejection up to 85 % and 78 % of BSA and egg albumin (EA), respectively. Moreover, analysis on the thermal features found that SDS, Triton X-100 and Tween 80 promoted better thermal stability and significantly fine molecular alignment which provided the versatility for the membrane to be used for any applications.

Electrochemical degradation of Azo-dye Acid Violet 7 using BDD anode: effect of flow reactor configuration on cell hydrodynamics and dye removal efficiency

2018 ◽  
Vol 48 (12) ◽  
pp. 1321-1330 ◽  
Author(s):  
Chrystiane N. Brito ◽  
Maiara Barbosa Ferreira ◽  
Elaine Cristina M. de Moura Santos ◽  
José J. Línares Léon ◽  
Soliu O. Ganiyu ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Azo Dye ◽  
Dye Removal ◽  
Flow Reactor ◽  
Electrochemical Degradation ◽  
Reactor Configuration ◽  
Bdd Anode ◽  
Acid Violet ◽  
Acid Violet 7 ◽  
Degradation Of Azo Dye

scholarly journals Membrane distillation of saline and oily water using nearly superhydrophobic PVDF membrane incorporated with SiO2 nanoparticles

2018 ◽  
Vol 78 (12) ◽  
pp. 2532-2541 ◽  
Author(s):  
N. Hamzah ◽  
M. Nagarajah ◽  
C. P. Leo
Keyword(s):  
Polyvinylidene Fluoride ◽  
Volume Ratio ◽  
Sio2 Nanoparticles ◽  
Membrane Distillation ◽  
Permeate Flux ◽  
Oil And Grease ◽  
Sem Images ◽  
Water Contact ◽  
Pvdf Membrane ◽  
Oily Water

Abstract Fat, oil and grease in wastewater generated from household kitchens, restaurants and food processing plants affect sewer systems, water resources and environment adversely. Hence, membrane distillation of saline and oily water was studied using a nearly superhydrophobic membrane developed in this work. Polyvinylidene fluoride (PVDF) membrane incorporated SiO2 nanoparticles was synthesized via phase inversion with dual baths and modified using hexadecyltrimethoxy silane. The volume ratio of silane to ethanol was varied between 1:200 to 1:25. The membrane characteristics were examined using a goniometer, a porometer, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The PVDF-SiO2 membrane modified using the volume ratio of 1:50 achieved the highest water contact angle of 141.6° and LEP of 2.642 bar. This membrane was further tested in membrane distillation to observe the permeate flux of distilled water, saline solution (1 M NaCl) as well as saline and oily solution (1 M NaCl; 1,000 ppm of palm oil). The modified PVDF/SiO2 showed high permeate flux which is nearly four times of the permeate flux of neat PVDF membrane, but still susceptible of salt and oil fouling as shown in SEM images.

scholarly journals Factors Affecting Reversible Pollution of Immersed Ultrafiltration Membrane in Treatment of Surface Water: Pilot Scale Studies

2010 ◽  
Vol 5 (3) ◽  
Author(s):  
Sun Lihua ◽  
Li Xing ◽  
Liu Ruiping ◽  
Sun Wenpeng ◽  
Li Guibai
Keyword(s):  
Surface Water ◽  
Membrane Fouling ◽  
Polyvinylidene Fluoride ◽  
Pilot Scale ◽  
Ultrafiltration Membrane ◽  
Permeate Flux ◽  
Critical Flux ◽  
Pvdf Membrane ◽  
Factors Affecting ◽  
Membrane Materials

The main factors (i.e., permeate flux, mixture characteristics, and membrane materials) affecting the pollution of immersed ultrafiltration membrane (immersed-UF) during the treatment of surface water were investigated through pilot scale studies. The variation of the running pressure was used as an indicator of membrane fouling. It is indicated that the rate of running pressure increased rapidly when the actual flux exceeded the critical flux, which exhibited to be 20 L·m−2·h−1 as for the membrane used in this study. The higher concentrations of turbidity and organic matter in the mixture contributed to the more significant increase of running pressure and the more serious membrane fouling. The higher temperature could lessen the membrane fouling to a certain extent. It was observed that membrane materials showed obvious effects on membrane fouling. The running pressure of Polyvinylidene Fluoride (PVDF) membrane was lower than that of chemically-modified Polyvinyl Chloride (PVC) at the same permeate flux, indicating the more promising potential of anti-pollution for PVDF membrane.

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