Superior arsenic adsorption by growing iron oxide nanoparticles inside electrospun PVA nanofibers

BORRAZÁS CAMILA; SANCHEZ OYARBIDE FACUNDO; PICÓN BORREGALES, DAVID EMMANUEL; ALICIA VERGARA; NICOLAS TORASSO; GOYANES, SILVIA

Congreso; 11 th WORLD CONGRESS OF CHEMICAL ENGINEERING; 2023

The problem of arsenic contamination in water demands sustainable, scalable, and easy-to-implement solutions. A recent method that solves the problem of using loose nanoadsorbents consists of generating a composite of poly(vinyl alcohol) (PVA) nanofibers containing iron oxide nanoparticles (IONP) synthesized in situ in an electrospinning solution. However, the concentration of adsorbent and the production rate of the membrane are limited by this method, both affecting scalability. In this work, an innovative method is proposed, that consists of synthesizing IONP within previously electrospun PVA nanofibers. This method exploits the water swelling capability of PVA. IONP were synthesized by submerging the nanofibers first in an iron solution and then in a NaOH solution, ensuring that the nanoparticles grow only in those regions within the polymeric matrix to which the water can reach.Membranes immersed in different concentrations of iron salts were studied and two types of PVA nanofibers were tested: with and without citric acid. Citric acid is expected to prevent crystallization and to provide spacing between the polymer chains. Morphological characterization was performed by SEM and inner interactions were studied by FTIR, which showed changes due to the increasing content of IONP and also hydrolysis reactions due to the submersion in NaOH solution Arsenic (V) adsorption results showed that the membranes developed herein tripled the adsorption capacity of the in situ method. Moreover, the system reaches equilibrium 10 times faster, which is expected from adsorbents placed closer to the surface of the nanofibers.