Abstract: Hydrophobic zeolites were prepared from mordenite and ZSM-5 by chemical liquid deposition with SiCl₄. Hydrophobicity Index( I_h) of the zeolites was determined from the competition adsorption of gasous n-heptane and water under specific conditions. The influences of the nature and Si/Al ratio of the original zeolites, pretreatment and deposition conditions on hydrophobicity were studied. the hydrophobic zeolites were characterized with XRD, IR, NH₃-TPDand N₂ adsorption methods, and their adsorbability for phenolic compounds from waste water was tested. The hydrophobicity of HZSM-5(Si/Al ratio is 100) treated by chemical liquid deposition is better than the commercial silicalite prepared from highly siliceous HZSM-5 by severe steaming at high temperture. Its I_h value is 1.7 times higher and its adsorption capacity for p-cresol in dilute solution of 0.2—0.4 mmol/Lis 1.3—1.7 times greater as compared to commercial silicalite.

Key words: Chemical liquid deposition, Hydrophobic zeolites, Waste water treatment