Novel activated carbon prepared from an agricultural waste,Stipa tenacissima, based on ZnCl2activation—characterization and application to the removal of methylene blue

Abstract

AbstractActivated carbon (AC) was prepared by means of a novel physiochemical activation method from low-cost biosorbent, agricultural waste (Stipa tenacissima fiber). A two-step pyrolysis was considered instead of a single-step pyrolysis, which involved zinc chloride for the first activation step and a steam mixture of water, CO2 and acetic acid for the second step. The obtained AC was tested as an adsorbent for the removal of a basic dye, Methylene blue (MB) from aqueous solutions. Batch experiments were conducted to examine the effect of the main parameters, such as the initial MB concentration, the pH, and the kinetic adsorption of this dye. Results showed that a pH value of 7 is favorable for the adsorption of MB. Rate constants of pseudo-first-order, pseudo-second-order, and intraparticle diffusion coefficient were calculated to analyze the dynamic of the adsorption process; they showed that adsorption kinetics followed a pseudo-second-order and an intraparticle diffusion model, while the two straig...