ADSORPTION CHARACTERISTICS OF SURFACTANTS AND PHENOL ON MODIFIED ZEOLITES FROM THEIR AQUEOUS-SOLUTIONS

Adsorption characteristics of anion-, cation- and nonion-type surfactants and phenol from their aqueous solution on Na-Y zeolites modified by SiCl4 treatment and Na-ZSM-5 zeolites with several Si/Al ratios were measured. Surfactants used were sodium dodecylbenzene-sulfonate (DBS), laurylpyridinium chloride (LPC), polyoxyethylene-nonylphenylether (POENPE) and phenol. Adsorption of surfactants was enhanced by SiCl4 treatment of Na-Y, which indicates an important role of the hydrophilic-hydrophobic character in the adsorption. Adsorption isotherms were in general of Langmuir type and adsorbed amount depended on the AII(Si + Al) or Si/Al ratio of zeolite frameworks. In case of DBS adsorption of Na-ZSM-5 series, adsorption occurred only on the outer surface due to steric hindrance. LPC adsorption abilities were observed on even hydrophilic zeolites and were ascribed to ion exchange effect. In case of phenol adsorption on hydrophobic Na-Y, the adsorption isotherm was of Type V according to BDDT classification.