Application of succinylated sugarcane bagasse as adsorbent to remove methylene blue and gentian violet from aqueous solutions – Kinetic and equilibrium studies

In a previous work, succinylated sugarcane bagasse (SCB 2) was prepared from sugarcane bagasse (B) using succinic anhydride as modifying agent. In this work the adsorption of cationic dyes onto SCB 2 from aqueous solutions was investigated. Methylene blue, MB, and gentian violet, GV, were selected as adsorbates. The capacity of SCB 2 to adsorb MB and GV from aqueous single dye solutions was evaluated at different contact times, pH, and initial adsorbent concentration. According to the obtained results, the adsorption processes could be described by the pseudo-second-order kinetic model. Adsorption isotherms were well fitted by Langmuir model. Maximum adsorption capacities for MB and GV onto SCB 2 were found to be 478.5 and 1273.2 mg/g, respectively.

► Succinylated sugarcane bagasse shows to be very efficient to remove MB and GV. ► Equilibrium adsorption data fit to the Langmuir model. ► Maximum adsorption capacities of MB and GV are found to be 478.5 and 1273.2 mg/g. ► The value of Qmax for GV is higher than other adsorbents reported in the literature. ► Both adsorption process are well described by pseudo-second-order model.