Eco-Friendly Cellulose/Polyaniline Sponge for Water Remediation

This work describes the fabrication of an eco-friendly sponge for the removal of dyes from aqueous solutions. For this purpose, a reused cellulose sponge (CS) that is commercially sold for makeup was covered with polyaniline (PANI), a conductive polymer that allows the addition of functional groups that are compatible with dyes present in aqueous solutions. An SEM analysis showed the successful deposition of PANI over CS fibers and confirmed that the porosity of the sponge remained after the polymerization step. The adsorption performance of the PANI-CS was evaluated in batch mode using methyl orange (MO). The adsorption capacity was 308 mg/g at pH 4.0 and after 110 min. PANI-CS achieved an adsorption percentage of 84% (C_o = 25 mg/L MO) after only 20 min. The experimental data were adjusted to different isotherm adsorption models; the best fit was obtained using the Halsey model. Furthermore, the adsorption performance of PANI-CS was studied in continuous mode using a bespoke adsorption column with recirculation. The results indicated that after 5 min of interaction time, 59% of the initial MO concentration (25 mg/L) was adsorbed. These results show the potential of PANI-CS as an inexpensive adsorbent for large-scale adsorption of dyes from aqueous media.