In-situ-surface polymerization of aniline on porous hollow MnO2-microspheres immobilized luffa cylindrica for Cr(VI) removal from electroplating wastewater: Comprehensive batch and column study

A novel in-situ-surface polymerization (ISSP) of aniline on luffa fibers (LF) was presented as a clean methodology for the modification of LF with polyaniline. The adsorbent's efficiency was evaluated by Cr(VI) adsorption from electroplating wastewater. The method consists of a surface pre-activation step with KMnO4, resulting in MnO2 immobilization on LF. The reusability of aniline solution represented a successful result up to eight times, revealing the advantage of this method compared to the conventional methods. The adsorbent characterization was performed by EDS, TGA, XRD, BET, FTIR, Raman, and FESEM analyses. FESEM images showed a more porous structure for the adsorbent prepared in ISSP method compared to the conventional method. The batch experiments revealed the optimum conditions (adsorbent, 3.0 g L-1; time, 60 min; pH, 2.0). Isotherm and kinetic studies were performed and the best fitted models were reported. The performance of the column study was analyzed using the Thomas model.