Abstract: The adsorption isotherms of tetradecylpyridium chloride (TPC) from aqueous solutions (before adsorption,pH 4～11) on zeolite 4Ahave been determined at 25℃.All the isotherms are of Langmuir type and similar ones.The result can be explained in that zeolite 4Ahas a quite large buffer ability,and pHvalues of the solutions before adsorption are close (pH 9～10).In the range of pH 8～10 the electroretic mobilition of zeolite 4A is a constant value.After adding NaCl and CaCl₂,the adsorption of TPC in lower concentration decreases markedly and the kind of the isotherms can be transform into Stype.

Key words: Zeolite 4A, Adsorption from solution, Tetradecylpyridium chloride