Adsorption equilibrium of zeolite on Fe~(3+) in wastewater and its kinetics characteristics

Iron ion is one of the main factors of affecting the drinking water quality.In order to evaluate the purification mechanism of iron ion in solution by zeolite,the batch experiments were conducted to study adsorption thermodynamics and kinetics characteristics of zeolite on Fe3+ in water solution.Results showed that adsorption equilibrium data well significantly fitted to Langmuir,Freundlich and Redlich-Peterson isotherms,and the process belonged to favorable adsorption.The theoretical saturated capacity was 2.486 g/kg.Lagergren's pseudo-second-order,Elovich and two-constant kinetic models were found to best represent the adsorption data,which was a rapid adsorption process.Kinetic analysis demonstrated the film liquid diffusion and intraparticle diffusion coexisted in the adsorption.Positive △H,△S and negative △G indicated that the adsorption was spontaneous,endothermic and entropy driven.