Evaluation of sesame stalk, sesame stalk bio-chars obtained from different temperatures and activated carbons for removal of heavy metal ions from aqueous solutions

In this study, the usage of sesame stalk, the natural waste of sesame which is an important oil plant in our country, was evaluated for removal of heavy metal ions and 2,4-D from aqueous solutions. This study included biosorption with raw biomass, and adsorption with bio-chars obtained by pyrolysis of sesame stalk at different temperatures and activated carbons obtained by chemical activation. Firstly, raw material was characterized and then the characterization of solid products obtained by heat treatment were carried out. Effects of different temperatures and chemicals were examined on the pore structure and the surface of obtained adsorbents. Raw material and solid products were characterized by using FT-IR and SEM characterization techniques. The effects of initial pH of the solution, adsorbent dosage, initial metal ion concentration, temperature and contact time on the removal of Fe(III), Cr(III) and 2,4-D from aqueous solutions were determined. Adsorption isotherms, kinetic expressions, and parameters of thermodynamic functions were calculated and discussed.Keywords: Heavy metal, Sesame Stalk, Bio-char, Activated Carbon, Adsorption, Characterization