Preparation of resin containing karbamotiyolilimidamit and use for removal of metal ions from aqueous solutions

In this study, a new adsorbent was prepared to remove chromium (VI) ions adversely affect human health even at low concentrations from aqueous solutions. For this purpose, a new monomer using 4-aminobenzonitrile and various reagents was synthesized. Using this monomer, resin was synthesized by suitable initiator and crosslinker. Then the desired adsorbent was prepared by performing alkali modification with thiourea in ethanol and was characterized by FTIR, TGA, SEM and BET analysis. The neutral pH point of adsorbent was determined. Later, the effects of initial ion concentration, pH, temperature, time, amount of adsorbent on adsorption were investigated. Moreover, on adsorption both anions like nitrate and sulfate and cations like lead, cadmium and nickel, were also investigated. The optimal adsorption conditions that adsorption was maximum and the maximum adsorption capacity was determined. In addition, isotherm, kinetic and thermodynamic studies were also carried out. It was found that adsorption equilibrium time was 6 hours, optimum pH was 2, the adsorption amount of chromium (VI) increased with increasing chrome concentration and increasing temperature. Cr (VI) adsorption results are applied Langmuir, Freundlich and Dubinin-Radushkevich isotherms and isotherm constants were calculated. Cr (VI) adsorption data showed compliance best with the Langmuir isotherm, and adsorption capacity of adsorbent was found 88.5 mg / g at 25 0C. Kinetic study data were evaluated with applying pseudo-first order kinetic model, pseudo-second order kinetic model and the particle intra-diffusion kinetic model and kinetic constants were calculated. From kinetic data, adsorption of Cr (VI) onto developed adsorbent was found to comply with pseudo-second kinetic model. From the results of thermodynamic study, values of ΔG0, ΔH0 and ΔS0 were calculated. It was determined that the adsorption was endothermic and spontaneous. Prepared adsorbent chromium (VI) adsorption was decreased at pH 2 in the presence of anions such as nitrate and sulfate, but in the presence of toxic metals such as Pb2+, Ni2+ and Cd2+ the adsorption of chrome was not affected, that is, adsorbent was found to be selective for Cr (VI). Keywords: Polymerization, Resin, Modification, Adsorption, Cr(VI), Kinetics, Thermodynamics.