Equilibrium studies of adsorption of amino acids on NaZSM-5 zeolite

The adsorption of amino acids such as phenylalanine, alanine, tyrosine and tryptophan on highly hydrophobic NaZSM-5 zeolite were studied. Selective adsorption of phenylalanine and tyrosine were observed. The single component adsorption isotherms were fitted in Langmuir model. For the amino acids considered in this work, the isotherms are essentially independent of pH, but they vary significantly with the temperature. Heats of adsorption were obtained from vanʹt Hoff plots of the Henryʹs law constant limit of the Langmuir isotherm and found to be higher for more hydrophobic solute.