Insights into the performance and mechanism of PANI@Hydroxapatite-Montmorillonite for hexavalent chromium Cr (VI) detoxification

In this work, a polyaniline-based Hydroxyapatite-Montmorillonite (PANI@Hap-Mt) composite was developed through an in-situ polymerization method. The porosity, crystallinity, morphology, and structural potentialities of the as-synthesized composite were assessed using various techniques (e.g. BET, SEM, XRD and FTIR). The composite was efficiently employed as an adsorbent material for hexavalent chromium Cr(VI) detoxification from solution. The influence of several operating conditions such as PANI@Hap-Mt amount, pH, contact time, temperature, and initial concentration of Cr(VI) ions were systematically investigated. The adsorption study demonstrated that a pseudo-second-order kinetic and Langmuir isotherm models were appropriate to anticipate the Cr(VI) adsorption process. Finally, the prepared composite exhibited a good regeneration capacity and a great reusability for Cr(VI) removal. These findings showed that the as-developed composite was a promising adsorbent for the detoxification of Cr(VI) from aqueous solution.