Abstract:In order to determine the adsorption characteristics of congo red by biosorbent chitosan,we studied the effects of pH,initial concentration,contact time and temperature.The result showed that the biosorption of congo red was significantly affected by initial solution pH,and the optimal pH of biosorption was 4 ~7.The kinetics of the interactions showed better agreement with the Lagergren second order kinetics,and indicated that capacity decreased with increasing temperature.The activation energy of biosorption(Ea) was determined to be 2.90 kJ/mol using Arrhenius equation.The adsorption data showed a good fit with Freundlich isotherm equation.Thermodynamic parameters,such as △Goand △Howere found as-10.10 kJ/mol(303 K) and-87.36 kJ/mol,respectively.The results indicated that the adsorption of congo red by chitosan was spontaneous and exothermic.The FTIR data showed that some functional groups mainly including-OH and-NH2 in chitosan were responsible for the adsorption of congo red.
