Removal of heavy metals from water using electrospun polyelectrolyte complex fiber mats

This study investigated the removal of heavy metals from water using electrospun polyelectrolyte (PE) complex fibers of polyacrylic acid (PAA) and polyallylamine hydrochloride (PAH). PE fiber mats were fabricated under various electrospinning operating conditions to optimize fiber size and stability in aqueous solution. The stable fiber mats were evaluated for their efficiency in removing heavy metals in synthetic metal solutions. The effect of water matrix on heavy metal removal using the PAA/PAH fiber mats was probed by comparing metal removals in the presence and absence of natural organic matter (NOM). The fiber mats exhibited approximately 63 %, 42 %, and 21 % removals of lead (Pb), cadmium (Cd), and copper (Cu), respectively in synthetic metal solutions at pH 3.4. Furthermore, approximately 70 %, 98 %, and 92 % removals of Pb, Cd, and Cu, respectively were observed at a higher pH (7.4). The heavy metal removal by the PAA/PAH complex fiber mats may be attributed to the association of the metal ions with carboxylate ions from the fibers. The presence of NOM in the metal-spiked solutions resulted in higher removal of metals by the fiber mats. This can be attributed to the availability of NOM-derived carboxylic acid groups, which resulted in increased metal-carboxylate complexations. This study implies that water matrix plays an important role that must be evaluated when removing metals using PE complex fibers.