BSA and humic acid separation from aqueous stream using polydopamine coated PVDF ultrafiltration membranes

doi:10.1016/j.jece.2017.05.051

Journal of Environmental Chemical Engineering

Volume 5, Issue 3, June 2017, Pages 2937-2943

https://doi.org/10.1016/j.jece.2017.05.051 Get rights and content

Highlights

•
Polydopamine (PD) coated antifouling poly (vinylidene fluoride) (PVDF) ultrafiltration (UF) membranes were successfully fabricated.
•
PD coated PVDF membranes demonstrated higher hydrophilicity, water permeation and flux recovery ratio (FRR) than pristine PVDF membrane.
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PVDF/PEG/PD membrane displayed the best antifouling tendency when the feed was an aqueous bovine serum albumin (BSA) and humic acid (HA) solutions.

Abstract

To inhibit the inherent hydrophobicity and low anti-fouling of poly (vinylidene fluoride) (PVDF) ultrafiltration (UF) membranes, poly (ethylene glycol) (PEG) and polydopamine (PD) were successfully utilized. Neat and PD coated PVDF membranes were prepared with and without the addition of PEG. PD coating on PVDF membrane surface was confirmed by attenuated total reflectance - Fourier transform infrared (ATR-FTIR) spectroscopy. To analyze the bulk as well as surface hydrophilicity, water content and contact angle measurements were made. The PVDF/PEG/PD membrane exhibited the highest pure water flux (118 Lm⁻² h⁻¹), water content (73.2%) and a lower water contact angle (61.5°), all of which confirms the improvement in hydrophilicity. The SEM imaging evidently demonstrated the notable morphological changes of the PVDF membrane after the modifications with PEG and PD. This PEG and PD modified membrane shows the lowest hydraulic resistance owing to the effect of the pore forming agent and a hydrophilic layer of PD. Humic acid (HA) and bovine serum albumin (BSA) were employed as foulants to analyze the separation performance and fouling resistance of the membranes. The PVDF/PEG/PD membrane exhibited the highest fluxes of 96.4 and 81.4 Lm⁻² h⁻¹ with rejections of 90.5% and 95.4%, respectively, when tested for BSA and HA solutions. It also showed a higher flux recovery ratio of 92.0% and 81.4% after the filtration of BSA and HA solutions, respectively. These results demonstrated that the superior permeation, separation and antifouling behavior of PVDF/PEG/PD membrane and thus promising for possible use as UF membrane in water and waste water treatment.

Graphical abstract

Introduction

Using clean and safe water in day-to-day life is still a dream for many people around the world. Though polluted water results in many diseases, people have no alternative, due to the minimal availability of pure water. To meet up the eternally increasing demand forclean water, the progresses in the field of water purification techniques have become the primary necessity. Many researchers are working in several fields to improve the quality and quantity of purified water. Among a large number of water purification techniques, membrane technology is one of the most important fields across the worlddue to the advantages such as, low cost, environment friendly approach, and several real time applications [1], [2].

Membrane technology consists of different types including reverse osmosis (RO), nano-filtration (NF), ultra-filtration (UF) and micro-filtration (MF). Among these,UF currently receives a wider attention due to their effectiveness in the disinfection of waste water by separating colloids, macromolecules and particles [3]. Recently UF becomes the field where many people work in due to its several real time applications in the pharmacy and food processing industry [4]. UF membrane should possess better anti-fouling property and stability as well as the higher water flux since it has been widely employed in water treatment to migrate the increasing water crisis worldwide [5].

The polymeric materials are considered to be an ideal choice for membrane preparations, due to their film-forming property and their unparalleled resistance to the extreme conditions of both preparation and separation processes in UF [6]. Among the broad range of polymers, due to its good thermal stability, mechanical property, membrane forming ability, outstanding chemical and oxidation resistance, PVDF is widely used as UF membrane materials [7]. PVDF also has high organic selectivity, that is it could be dissolved in some highly polar organic solvents like, N, N-dimethylacetamide (DMAc), N, N-dimethyl formamide (DMF) and N-methyl-2-pyrrolidone (NMP), etc., a unique property which many polymers don’t possess [8]. Nonetheless, one of the factors which limit the broad applications of the PVDF membranes is that they were easily fouled, due to their hydrophobic nature. The low fouling resistance results in frequent replacement of membranes, which augments the cost of the separation process. Especially, the pure PVDF membranes are easily get contaminated by proteins and other kind of impurities in waste water disinfection and water treatment that results in sharp drop in pure water flux of the membrane [9].

In order to overcome these limitations, surface modifications of pristine polymer membranes such as blending, chemical coating, adsorption, plasma treatment, etc., were employed by the researchers. It is accepted by many researchers that, improvement in the hydrophilicity of the polymer enhances the fouling resistance in the membrane [10]. Recently, PD coating has received intensive attention as an attractive strategy for membrane surface modification. This modification technique has many advantages including: high anchoring capability, self-polymerization and special recognition. Moreover PD can remarkably improve the surface hydrophilicity while just forming a very thin layer on any substrate surface. It has the plentiful catechol groups and ethyl amino groups in dopamine, which favors the formation of hydrophilic polymer layer on the surfaces of most substrates polycarbonate (PC), polyethylene (PE), polysulfone (PS), PVDF, etc., via polymerization of dopamine [11], [12], [13], [14], [15], [16].

Besides the PD coating, the addition of a pore forming agent has a positive effect in water permeability since it increases the size and number of pores in the membrane [17], [18]. Polyethylene glycol (PEG) of average molecular weight 600 Da is an efficient pore forming agent that enhancing the membrane’sporosity and hydrophilicity, as it leaching out of the solution during the phase separation process. Moreover, PEG additive can be physically blended with PVDF to enhance membrane hydrophilicity thus reduce membrane fouling [19].

In this study, PD was synthesized, coated on the PVDF and novel surface modified PVDF/PEG blended UF membranes were fabricated. Membrane hydrophilicity properties were studied by pure water flux, percentage water content, compaction, hydraulic resistance, SEM and contact angle analysis. The fouling resistance and separation characteristics of the fabricated membranes were analyzed using humic acid (HA) and bovine serum albumin (BSA) as foulants and results are discussed in detail.

Section snippets

Materials

Poly (vinylidene fluoride) (PVDF) was received from Sigma Aldrich Inc. (St. Louis, MO), polyethylene glycol of average molecular weight 600 Da (PEG 600) was provided by Loba Chemie Pvt. Ltd., BSA of molecular weight ∼66 kDa and HA were obtained from Sigma Aldrich Inc. (St. Louis, MO). N-methyl-2-pyrrolidone (NMP) was purchased from Merck Specialities Pvt. Ltd., sodium lauryl sulphate (SLS) of AR grades were procured from Spectrum Reagents and Chemicals Pvt. Ltd. Sodium dibasic phosphate

ATR-FTIR spectra

The surface properties of the membrane samples were studied by employing ATR-FTIR technique. In this study, the reflected radiation penetrates the sample to a depth of only a few microns. This is why this technique is being independent of membrane’s thickness. Hence this is an effective method studying the surface properties of the membrane sample [31]. Mixing of PVDF and PEG in NMP formed a homogeneous and transparent solution; but, after the PD coating, the PVDF membrane became dark brownish

Conclusions

The PVDF and PVDF/PEG blended membranes were prepared with PD coating by phase inversion method. The morphology, hydrophilicity, fouling properties, and stability of the membranes were examined and the results were analyzed. From the results it was found that:

(1)
Membrane characterizations by ATR-FTIR, confirms the existence of PEG and PD in the membrane surface.
(2)
Though PVDF/PEG and PVDF/PD membranes showed improved hydrophilicity compared to the neat membrane, the synergistic effects of PEG and PD

References (40)

B.D. McCloskey et al.
A bioinspired fouling-resistant surface modification for water purification
J. Membr. Sci.
(2012)
C.W. Lee et al.
Application of ultrafiltration hybrid membrane processes for reuse of secondary effluent
Desalination
(2007)
K. Katsoufidou et al.
A study of ultrafiltration membrane fouling by humic acids and flux recovery by backwashing: experiments and modeling
J. Membr. Sci.
(2005)
D. Möckel et al.
Static protein adsorption:ultrafiltration behavior and cleanability of hydrophilized polysulfone membranes
J. Membr. Sci.
(1999)
L.Y. Yu et al.
Preparation and characterization of PVDF–SiO₂ composite hollow fiber UF membrane by sol–gel method
J. Membr. Sci.
(2009)
H.K. Lonsdale
The growth of membrane technology
J. Membr. Sci.
(1982)
S.S. Chin et al.
The stability of polymeric membranes in a TiO₂ photocatalysis process
J. Membr. Sci.
(2006)
L.-Q. Shen et al.
Ultra-filtration hollow fiber membranes of sulfonated polyetherimide blends: preparation:morphologies and anti-fouling properties
J. Membr. Sci.
(2003)
L. Liu et al.
Polydopamine coating −Surface modification of polyester filter and fouling reduction
Sep. Purif. Technol.
(2013)
B.D. McCloskey et al.
Influence of polydopamine deposition conditions on pure water flux and foulant adhesion resistance of reverse osmosis, ultrafiltration, and microfiltration membranes
Polymer
(2010)

F. Li et al.

Surface modification of PES ultrafiltration membrane by polydopamine coating and poly(ethylene glycol) grafting: morphologystability, and anti-fouling

Desalination

(2014)

D.J. Miller et al.

Short-term adhesion and long-term biofouling testing of polydopamine and poly (ethylene glycol) surface modifications of membranes and feed spacers for biofouling control

Water Res.

(2012)

L. Shao et al.

A facile strategy to enhance PVDF ultrafiltration membrane performance via self-polymerized polydopamine followed by hydrolysis of ammonium fluotitanate

J. Membr. Sci.

(2014)

C. Zhang et al.

Poly(dopamine)-assisted preparation of star poly(ethylene glycol)-based coatings: a detailed study of their protein resistance and application in CE

React. Funct. Polym.

(2015)

L. Wu et al.

Poly (vinylidene fluoride)/polyethersulfone blend membranes: effects of solvent sort, polyethersulfone and polyvinylpyrrolidone concentration on their properties and morphology

J. Membr. Sci.

(2006)

P. Kanagaraj et al.

Separation of macromolecular proteins and rejection of toxic heavy metal ions by PEI/cSMM blend UF membranes

Int. J. Biol. Macromol.

(2015)

C. Barth et al.

Asymmetric polysulfone and polyethersulfone membranes: effects of thermodynamic conditions during formation on their performance

J. Membr. Sci.

(2000)

J. Ou et al.

Fabrication and biocompatibility investigation of TiO₂ films on the polymer substrates obtained via a novel and versatile routes

Colliods Surf. B Biointerfaces

(2010)

A. Nagendran et al.

Toxic metal ion separation by cellulose acetate/sulfonated poly (ether imide) blend membranes: effect of polymer composition and additive

J. Hazard. Mater.

(2008)

J. Kochan et al.

Impact of wetting agents on the filtration performance of polymeric ultrafiltration membranes

Desalination

(2009)

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BSA and humic acid separation from aqueous stream using polydopamine coated PVDF ultrafiltration membranes

Highlights

Abstract

Graphical abstract

Introduction

Section snippets

Materials

ATR-FTIR spectra

Conclusions

J. Membr. Sci.

Desalination

J. Membr. Sci.

J. Membr. Sci.

J. Membr. Sci.

J. Membr. Sci.

J. Membr. Sci.

J. Membr. Sci.

Sep. Purif. Technol.

Polymer

Desalination

Water Res.

J. Membr. Sci.

React. Funct. Polym.

J. Membr. Sci.

Int. J. Biol. Macromol.

J. Membr. Sci.

Colliods Surf. B Biointerfaces

J. Hazard. Mater.

Desalination