Crystal violet dye removal from aqueous water using polyacrylonitrile precursor beads

The removal of Crystal Violet (CV) Dye by adsorption has been investigated using Polyacrylonitrile-based beads (PAN) as an adsorbent. The beads wereprepared using the phase inversion method and then characterizedusing SEM, BET, and FTIRanalyzes. Different adsorption parameters were tested, such as pH solution, adsorbent dose, adsorbate concentration, rotating speed, and temperature. The equilibrium data were examined by Langmuir and Freundlich's isotherms. A kinetic study using pseudo-first-order and pseudo-second-order was made to investigate the adsorption mechanism. The maximum removal percentage of thedye was 98% at the optimum condition (pH = 7, C-o = 10 mg/l, B-o = 0.4 g, T = 35 degrees C, and 200 rpm), and the process reached equilibriumtime in 5 hr. The pseudo-second-order gives the best conformity than pseudo-first-order; the data also showed the best fitting to Langmuir isotherm. The thermodynamic study revealed a spontaneous and endothermic process. The adsorbent was regenerated with HCl solution and reused up to 6 times with91%removal. (C) 2021 Elsevier Ltd. All rights reserved.