CHEMICAL LIQUID DEPOSITION AND HYDROPHOBICITY OF ZEOLITES

Hydrophobic zeolites were prepared from mordenite and ZSM-5 by chemica l liquid deposition with SiCl4. Hydrophobicity Index(I-h) of the zeoli tes 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 con ditions on hydrophobicity were studied. the hydrophobic zeolites were characterized with XRD, IR, NH3-TPD and Nz adsorption methods, and the ir adsorbability for phenolic compounds from waste water was tested. T he hydrophobicity of HZSM-5(Si/Al ratio is 100) treated by chemical li quid 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 i n dilute solution of 0.2-0.4 mmol/L is 1.3-1.7 times greater as compar ed to commercial silicalite.