In situ deposition of polyaniline onto sisal fibers and removal efficiency for chromium (VI) from aqueous solution: Structure and adsorption studies

In the present study, polyaniline was coated on the surface of sisal fibers through in situ oxidative polymerization which was further characterized using FT‐IR, UV‐Vis, XRD, SEM and EDX instruments. The composite was tested to remove hexavalent chromium Cr(VI) from simulated wastewater on batch experimentas a function of contact time, solution pH, particle size, adsorbent dose and adsorbate dose. Peaks in the range of 1480‐1580 cm‐1 from FT‐IR spectra confirmed polyaniline is rich in amino polyfunctionalities. Another peak at 1160 cm‐1 proved introduction of polyaniline in the doped state. An EDX spectrum exhibits a characteristic peak of C, N, O and Cl atoms that verify deposition of polyaniline on the surface of sisal fibers. It was observed that adsorption of Cr(VI) is highly susceptible to pH change with the adsorption removal of 93.1% achieved at pH 4. Studies on adsorption reaction revealed adsorption process followed pseudo second orderkinetics confirming chemisorption as a rate determining step. The isotherm data were suitably fitted tothe Langmuir model with maximum adsorption capacity (qm) of 17.86 mg/g when all adsorption variables were optimized