A review, with 47 refs., of thermal and chem. methods for activation of natural zeolites use as sorbents in air pollutants. Dealumination of zeolites by leaching with strong acids was also taken into consideration. Data on the sorption efficiency of the activated adsorbents in sepn. of H2S, CO2, PrH, AcOBa, Me2CO, MeH, EtH and ethylene were included.