Removal of organic pollutants by surfactant modified zeolite: Comparison between ionizable phenolic compounds and non-ionizable organic compounds

► Surfactant modified zeolite could greatly retain organic pollutants. ► Uptake of organic compounds was due to the loaded surfactant. ► kow is crucial for the uptake of both ionizable and non-ionizable organic solutes. ► pKa is another factor affecting adsorption process of ionizable organic pollutants. ► Adsorption mechanisms of the two kinds of organic pollutants were proposed.