Enhanced removal of Bismark Brown (BB) dye from aqueous solutions using activated carbon from raw Ziziphusspina-christi (ZSAC) Equilibrium, thermodynamic and kinetics

In this study, carbon was easily made from walnut wood as a low-cost and non-toxic natural adsorbent. Ziziphusspina-christi (ZSAC), an excellent adsorbent, were successfully synthesized by an in chemical vapor deposition method and used for the removal of Bismark Brown(BB) dye from aqueous solution. The as-synthesized Ziziphusspina-christi (ZSAC) were characterized by FT-IR technique. Various operational parameters such as pH, initial dye concentration and contact time in batch systems were investigated on the use of Ziziphusspina-christi (ZSAC). Equilibrium data obtained have been fitted to the Langmuir, Freundlich, Tempkin, and Dubinin–Radushkevich adsorption isotherms. Langmuir isotherm best fits the experimental results. Kinetic modeling of pseudo -first order and pseudo-second order showed that the pseudo-second order equation was the most appropriate for the description of Bismark Brown(BB) dye adsorption by (ZSAC). The maximum sorption capacity qmax in Langmuir isotherm of (BB) 35.88 mg/g showed onto (ZSAC), The overall adsorption process was exothermic and spontaneous in nature. The thermodynamic functions (ΔSº, ΔHº, ΔGº) of the studied reaction are calculated using activated complex theory and show that adsorption (BB) dye onto (ZSAC) process requires heat. The results indicated that Bismark Brown (BB) adsorption onto Ziziphusspina-christi (ZSAC)might be a physical adsorption.