Electrospun Composite Nanofiltration Membranes for Arsenic Removal

Abstract

In recent years, significant attention has been paid towards the study and application of mixed matrix nanofibrous membranes for water treatment. The focus of this study is to develop and characterize functional polysulfone (PSf)-based composite nanofiltration (NF) membranes comprising two different oxides, such as graphene oxide (GO) and zinc oxide (ZnO) for arsenic removal from water. PSf/GO- and PSf/ZnO-mixed matrix NF membranes were fabricated using the electrospinning technique, and subsequently examined for their physicochemical properties and evaluated for their performance for arsenite–As(III) and arsenate–As(V) rejection. The effect of GO and ZnO on the morphology, hierarchical structure, and hydrophilicity of fabricated membranes was studied using a scanning electron microscope (SEM), small and ultra-small angle neutron scattering (USANS and SANS), contact angle, zeta potential, and BET (Brunauer, Emmett and Teller) surface area analysis. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were used to study the elemental compositions and polymer-oxide interaction in the membranes. The incorporation of GO and ZnO in PSf matrix reduced the fiber diameter but increased the porosity, hydrophilicity, and surface negative charge of the membranes. Among five membrane systems, PSf with 1% ZnO has the highest water permeability of 13, 13 and 11 L h−1 m−2 bar−1 for pure water, As(III), and As(V)-contaminated water, respectively. The composite NF membranes of PSf and ZnO exhibited enhanced (more than twice) arsenite removal (at 5 bar pressure) of 71% as compared to pristine PSf membranes, at 43%, whereas both membranes showed only a 27% removal for arsenate.

Antifouling and Antimicrobial Study of Nanostructured Mixed-Matrix Membranes for Arsenic Filtration

“…A possible foulant layer might be porous as well. Membranes are mesoporous and have pore sizes ranging from 0 to 100 nm [ 29 ]. Thus, the fouling-induced changes in the micropore region (<2 nm), mesopore region (2–50 nm), and macropore region (≥50 nm) were of interest.…”

“…Three electrospun nanofibrous mixed-matrix membranes were used for this study, as reported earlier [ 29 ]. The membranes were P, CP, and MCP.…”

“…Antifouling experiments were performed using crossflow filtration equipment as mentioned in our previous study [ 29 ] for pure water and arsenic-contaminated water at different levels of pressure between 2 bar and 7 bar. First, pure or arsenic-contaminated water was passed through the membrane for 80 min at operating pressure, resulting in a stable water flux (J 1 ), which was recorded.…”

“…Therefore, an attempt was made to investigate the antibacterial and antifouling properties of PSF electrospun membranes and PSG modified with nanoparticles for arsenic filtration as a continuation of our previous study reported earlier [ 29 ].…”

Advanced Polymeric Nanocomposite Membranes for Water and Wastewater Treatment: A Comprehensive Review

“…Mixed matrix membranes (MMMs) are membranes in which NPs are embedded as a dispersed phase into a polymer matrix, which can be achieved using techniques such as PI, electrospinning, crosslinking, LBL deposition, etc. [ 77 , 78 , 79 , 80 , 81 , 82 ]. This review will mostly focus on nanomaterials incorporated in the polymer substrate, but a few examples of other possibilities shall be discussed as well.…”