Abstract: In the present research Arsenic removal by Dissolved Air Flotation (DAF) has been studied in pilot scale. Polyaluminium chloride is best coagulant for arsenic removal is primary turbidity of 10 NTU and coagulant concentration of 40 mg L-1 and saturation Pressure of 4.5 atmosphere. Survey of flocculation time, flotation time and saturation pressure on arsenic removal by dissolved air flotation has shown that their effect on arsenic removal is identical (same). Arsenic has been removed about 99% by this method.