Statistical optimization of activated carbon from Thapsia transtagana stems and dyes removal efficiency using central composite design

Abstract

This study focused on the preparation of activated carbons from Thapsia transtagana stems by boric acid activation and their evaluation for dyes removal. The central composite design and response surface methodology were used to optimize the preparation conditions. The effect of activation temperature, impregnation ratio and activation time on iodine number (IN), methylene blue index (MB index) and removal efficiencies of methyl violet (MV), methyl orange (MO) and indigo carmine (IC) were fully evaluated. The activated carbon samples prepared in optimal conditions were characterized by FTIR, XRD, SEM-EDX, Boehm's titration, and point of zero charge (pHPZC). The equilibrium data for dyes sorption onto optimum activated carbons were best fitted with Langmuir isotherm. Keywords: Thapsia transtagana stems, Dyes removal, Chemical activation, Central composite design