Efficient and selective sequestration of perfluorinated compounds and hexavalent chromium ions using a multifunctional spinel matrix decorated carbon backbone N-rich polymer and their mechanistic investigations

The removal of emerging contaminants including heavy metals and perfluorinated compounds has been an increasing concern globally due to their harmful effects on human health and other creatures in the environment. Mixtures of perfluorinated chemicals with heavy metals are often found in polluted areas, which is a critical challenge in water remediation. This study proposes a multifunctional magnetic adsorbent, cerium-incorporated ferrite (CMF) decorated polyaniline (PANI) (CMFx%@PANI) hybrid composites by co-precipitation followed by calcination methods. FTIR, VSM, and zeta potential measurements confirmed the successful incorporation of CMF on PANI. The textural properties and surface morphologies of CMFx%@PANI were examined using BET, FE-SEM, HR-TEM, and EDX analysis. The conventional raw forms of CMF nanoparticles and PANI were inadequate for the removal of the mentioned contaminants. However, the synchronous role of PANI with CMF nanoparticles exhibited higher adsorption capacities toward the perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and hexavalent chromium (Cr(VI)) ions than the individual forms. The sorption kinetics and isotherms indicated that adsorption behaviors of PFOA, PFOS, and Cr(VI) onto CMFx%@PANI followed a pseudo-second-order and Langmuir isotherm model, respectively. The feasible mechanisms of PFOA, PFOS, and Cr(VI) adsorption on CMFx%@PANI were investigated using XPS analysis.