Composite Anion Exchange Membranes with Antibacterial Properties for Desalination and Fluoride Ion Removal

Abstract

The contamination of fluoride ions in groundwater and membrane fouling due to the growth of bacteria in wastewater are serious problems. We report the preparation of a composite anion exchange membrane (AEM) with enhanced antimicrobial properties for water desalination and fluoride ions removal from water by electrodialysis (ED). The composite membranes were prepared by impregnating silver nanoparticles (AgNPs) in the N-alkylated terpolymer of poly(acrylonitrile), poly(n-butyl acrylate), and poly[(2-dimethyl aminoethyl) methacrylate], followed by cross-linking by the reaction with hydrazine hydrate. The key factors are the variation of alkyl chain length attached with −N(CH 3 ) 2 − in the membrane matrix, optimizing the water uptake and impregnation of AgNPs. The presence of AgNPs in the AEMs was confirmed by UV−visible spectroscopy, transmission electron microscopy, and EDAX mapping. The incorporation of 0.03 wt % AgNPs in the AEMs increases 8.5−12.5% water uptake and 8−12% ionic conductivity. The representative M-C10/AgNPs membrane exhibited 0.72−0.74 kWh/kg power consumption and 96−95% current efficiency during the removal of fluoride ions (5.5−11 mg/L) from water containing NaCl (concentration: 2000 mg/L) by ED process. No detectable leaching of AgNPs was observed by continuous exposure of the composite AEMs in water at 50 °C for 15 days.

Biological Synthesis of Silver Nanoparticles by Amaryllis vittata (L.) Herit: From Antimicrobial to Biomedical Applications

“…The standard drug (streptomycin) and distilled water were used as +ve and −ve controls, respectively. All plates were incubated at 25 °C for 24 h. Antibacterial activity was observed by measuring inhibition zones with an ordinary scale [ 15 , 21 ].…”

“…The synthesized AgNPs were characterized by different techniques, such as FTIR spectroscopy, SEM, EDX, XRD, and TEM analysis. The nanoparticles’ antibacterial [ 15 ], antioxidant, phytotoxic, antifungal, insecticidal, and analgesic activities were also investigated to explore their biomedical potentiality.…”

Perspectives on Dual‐purpose Functional Nanomaterials for Detecting and Removing Fluoride Ion from Environmental Water

“…In the ion exchange method, ion exchange resins with a strong affinity for F À ions can effectively remove F À from water. [21] The resin facilitates the exchange of other ions (such as chloride) for fluoride ions. Regeneration of the resin is necessary after it becomes saturated with fluoride.…”

Internally Cross-Linked Polysulfone-Based Anion Exchange Membranes with pH Stability for Carboxylate Separation

“…Among these techniques, ED stands out as a promising and sustainable technology, thanks to its high selectivity for ionic compounds, ease of operation, and low carbon footprint. − In ED, target carboxylates can be selectively separated from liquid streams based on electro-driven of ions that transport through ion-exchange membranes (IEMs). − An appropriate anion exchange membrane (AEM) for the desalination of carboxylate must exhibit a high organic ion transport capability and pH stability. − Due to its affordability, robust physical-chemical stability, and chemical reactivity, polysulfone (PSF) is commonly used for membrane fabrication. , Particularly, chlorinated PSF (CMPSF), which can be easily reacted with some functional monomers via a substitution reaction, has been explored to create polymers with ion exchange capacities (IECs) for IEMs. For example, based on the functionable sites of trimethylamine and triethylamine, Tang et al.…”