Chitosan/clay composites synthesis, characterization and Cu (II) adsorption use

In this study, bentonite clay that is commonly available in our country to remove the Cu (II) ion from the aqueous solution and chitosan bio-polymer that is obtained from chitin which is the second commoner after the cellulose in nature, and the composite materials that are made up of these two natural adsorbents were used.Chitosan contains reactive hydroxyl (?OH) groups and amino (?NH2) groups that have the potential to bind heavy metals. However, using pure chitosan as an adsorbent has several disadvantages such as low surface area, low speci ? c gravity, high cost, and weak chemical and mechanical properties. Composites based on chitosan were constructed to develop chitosan?s mechanical power, not to solve the strong acid, and to raise the qualities of adsorption.Clays have been used often in adsorption studies but in practically studies clays show some negative effects on hydrodynamic properties such as aggregation and coagulation. These negative effects can be removed by using the composites which polymers combining with clays. Particularly, chitosan/clay composites have been tested in removing the heavy metals and used in most studies.In this study, chitosan/bentonite composite synthesized and used to adsorption Cu (II) from aqueous solution. The effect of temperature, the initial metal concentration, pH, and velocity on adsorption was investigated. Moreover, some studies on the adsorption competition were performed. Velocity constants were found by interpreting the kinetic data on pseudo first, pseudo second, Weber- Morris and pore diffusion models. By using Langmuir and Freundlich adsorption models and analyzing adsorption balance, constants, relating to these models were calculated. Furthermore, by IR and SEM analysis, the characterization of adsorbents were carried out.