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 (PAni) was coated on the surface of sisal fibers (SF) through in situ oxidative polymerization method which was further characterized using FT-IR, UV-Vis, XRD, SEM and EDX instruments. PAni/SF composite was tested to remove potentially harmful hexavalent chromium(CrVI) from simulated waste water on batch adsorption experiment as a function of adsorption variables such as contact time, solution pH, particle size, adsorbent dose and adsorbate dose.It was observed that adsorption of Cr(VI) is highly susceptible to pH change with maximum adsorption removal (93.1%) and adsorption capacity (12.7 mg/g) achieved at pH 4. Studies on adsorption reaction revealed adsorption process followed pseudo second order kinetics confirming chemisorption as rate determining step. The isotherm data was suitably fitted to Langmuir model with maximum adsorption capacity (qm) 17.86 mg/g when all adsorption variables were optimized.