Surface grafting of polyvinyl alcohol (PVA) cross-linked with glutaraldehyde (GA) to improve resistance to fouling of aromatic polyamide thin film composite reverse osmosis membranes using municipal membrane bioreactor effluent

Abstract

Membrane surface modification is a favourable method to handle fouling during wastewater treatment processes. In this study, grafting of polyvinyl alcohol (PVA) through cross-link with Glutaraldehyde was applied to a thin film composite reverse osmosis membrane to enhance the resistance to flux decline. The analytical analyses attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy were performed to evaluate the impact of surface modification. Biofouling using Escherichia coli (E. coli) bacterial solution and fouling tests using a bench scale reverse osmosis system with a simulated secondary effluent from a membrane bioreactor were used to assess the impact of the surface modification initiated on antifouling properties of the membrane. It was shown that the morphological structure and the chemical properties of the membrane were altered, whereas the pure water flux slightly decreased after modification. Although a slight decrease of salt rejection was observed, the membrane resistance to fouling improved and the biofouling model used revealed the anti-biofouling capacity of the membrane. The flux decline and flux recovery ratios improved with an increase in PVA concentration. The sterilization ratio increased from 33.8 to 36.8% and the pure water flux decline decreased from 46.04 to 25.94% after modification.

Surface Modification of TFC-PA RO Membrane by Grafting Hydrophilic pH Switchable Poly(Acrylic Acid) Brushes

“…In another relevant study, the TFC-PA membrane was grafted by polyvinyl alcohol (PVA) crosslinked with glutaraldehyde. The membrane showed a water flux of 40 to 30 L m -2 hr -1 , and salt rejection was found to be in the range of 85 to 87% [69]. The pH-responsive salt rejection evaluation of the TFC-modified membranes with PAA brushes in the present work is valuable and support various studies discussed here and can lead to the next generation of advances in polymer membranes with simultaneous control of both flux and salt rejection.…”

Poly(vinyl alcohol)‐based membranes for fuel cell and water treatment applications: A review on recent advancements

“…Another widely used approach for surface grafting of PVA‐based polymers on PA RO membranes at active hydrogen sites involves covalent bonding of grafting agent, such as glutaraldehyde. In this process, PA RO membranes were first chemically treated with GA solution to bond GA at active sites of PA membrane; and in the second step, the PVA‐based polymer was grafted onto the PA surface via grafting agent GA. PVA, 165,167 and l ‐Arginine‐ g ‐PVA (Arg‐ g ‐PVA), 28 have been successfully grafted on RO membranes using GA as a grafting agent. These PVA‐modified membranes showed improvement in salt retention, antifouling characteristics and chlorine tolerance.…”

Exclusion of Estrogenic and Androgenic Steroid Hormones from Municipal Membrane Bioreactor Wastewater Using UF/NF/RO Membranes for Water Reuse Application

“…Table 1 shows a summary of the experimental conditions. The permeate flux (J) was calculated using the volume of permeate (V) collected through the active surface area of membrane (A) for a given period of time (∆t), as shown in Equation 2 [12].…”

“…Given that conventional treatment processes are less efficient, the scientific community set out in search of novel processes and operating conditions, which could increase the treatment efficiency of wastewater [11]. Nanofiltration (NF) and reverse osmosis (RO) membrane filtration processes have also been used to produce high-quality water from non-traditional sources such as brackish, seawater, or secondary treated wastewater [12]. Research has demonstrated the excellent capacity of NF/RO to remove a large range of MPs in pilot and full-scale applications [13].…”