ADSORPTION OF CATIONIC BASIC DYE FROM AQUEOUS SOLUTION ONTO ACTIVATED CARBON DERIVED FROM BANANA PEEL

摘要

Dyes are toxic and cause severe problems to aquatic environment. Adsorption is one of the most effective applied techniques for the removal of dyes from the industrial effluents. The use of cheap and eco-friendly adsorbents has been studied as an alternative source of activated carbon for the adsorption of dye.Banana peel, an abundant agricultural by-product in Delta region, Egypt, was used to prepare activated carbon by thermal activation in an inert atmosphere. Adsorptive removal of cationic basic dye, methylene blue (MB) from waste water onto dried banana peel (BP) and activated carbon prepared from banana peel (BPAC) were studied in a batch system. The effects of adsorbent dosage, pH, contact time, initial dye concentration, and temperature on the adsorption performance were investigated. The banana peel and its activated carbon were characterized by FT-IR and scanning electron microscopy (SEM).The experimental equilibrium data were examined using Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, and Harkins-Jura isotherms. The adsorption kinetic dye was analyzed using pseudo-first order, pseudo-second order, and Elovich models. The intraparticle diffusion model was used to study the kinetic mechanism of basic dye adsorption.The experimental results showed that the adsorptive removal of dye increased with increasing the pH of solution, temperature, adsorbent dose, contact time and decreased with increasing the initial dye concentration. The adsorptive removal of methylene blue onto BP and BPAC were 90% and 98 % respectively at pH 6, 35 °C and adsorbent dose 5 g/L. The equilibrium contact time for the adsorption process onto BP and BPAC were 45 min and 30 min respectively. The adsorption process fitted well to pseudo-second-order kinetics (R2 =0.998). The adsorption isotherm models fitted the data in the order: Temkin > Freundlich > Langmuir isotherms.The results indicated that BP and BPAC are efficient and low-cost adsorbents for dye removal.