adsorption capacity

hg ii

natural organic

pb ii

adsorption process

oil sorption

contaminated water

fe nps

Journal of environmental chemical engineering

• Magnetic iron oxide nanoparticles were immobilized inside electrospun PVA nanofibers. • High arsenate adsorption capacity is achieved. • Magnetic analysis showed the confinement and well dispersion of MIONs in nanofibers. • SAXS/WAXS techniques permitted macroscopic analysis of PVA-MIONs. • Adsorption process occurs in three steps: swelling, adsorption and equilibrium. Superparamagnetic iron oxide nanoparticles (SPIONs) are great adsorbents of toxic arsenic in water. However, SPIONs efficiency is limited by a tendency towards agglomeration, and an extra filtering process is required in actual applications to avoid possible harmful effects of nanoparticles released to the environment. Here, we show a novel green method to confine and disperse SPIONs (10 nm) inside insoluble electrospun PVA nanofibers (final concentration 0.14 wt. %). We found that the resulting membrane has an enhanced arsenic adsorption capacity (> 52 mg/g) and presents a new adsorption mechanism, involving a high swelling of the superhydrophilic nanofibers before actual solution interchange can occur. A suitable heat treatment provided water insolubility to the membrane while maintaining hydrophilicity and active sites in the SPIONs. We show the excellent dispersion and homogeneous distribution of the SPIONs inside the nanofibers using electron microscopies and scale this analysis to an area of statistical significance via magnetic studies and novel Small and Wide Angle X-Ray Scattering SAXS/WAXS 2D scannings. The production process is environmentally friendly, given that only PVA was used as SPIONs dispersant and no chemicals were added for crosslinking. This work presents a novel material that expands the broad technological applications of both iron oxide nanoparticles and electrospinning, opening a route to new horizons in water purification.

Enhancing arsenic adsorption via excellent dispersion of iron oxide nanoparticles inside poly(vinyl alcohol) nanofibers