In this study, a successful degradation of phenol was achieved by a combination of processes, ultrasonic irradiation and periodate. The effect of pH, dosage of IO4-, dosage of initial phenol and ultrasonic irradiation time on the phenol degradation were examined. Furthermore, the impacts of ion intensity on phenol degradation were examined. The findings indicated that the disgrace ratio advanced in acidic conditions and an upper degradation was achieved in combination processes. The current new investigation examined the effect of ion intensity and the findings determined that the principal intensity of solution is an inactive variable on phenol disgrace with these systems. A comparison research among IO4-/ US system and IO4- and US separately determined the COD removal and indicated that an combined method of IO4-/ US system had the best execution.