Mexican-origin clinoptilolite, (Na0.42K1.86Mg0.46Ca1.34) [Si30.16Al5.83O72](.)nH(2)O, best particle size 0.1-0.5 mm, and com. acrylamide polyelectrolytes were examd. in the settllng-and-flotation treatment of a model refinery wastewater, 200 mg crude Soviet Export Blend/dm(3)H(2)O, emulsified and devolatized at 80&DEG; C. The polyelectrolytes raised the surface tension of the wastewater to 79.5 dynes/cm and enhanced considerably the efficiency of flotation. Subsequent adsorption of hydrocarbons by filtration of the wastewater through a clinoptilolite bed reduced their concn. to < 4 mg/dm(3).