Nano-sized metal oxides and their concentrations         Sonodegradation removals (%)
CODdis Phenol TAAs Color
Control without nano-sized metal oxides 61 61 66 50
TiO2 = 2 mg/L 92 90 86 85
TiO2 = 4 mg/L 97 97 88 94
TiO2 = 8 mg/L 90 94 83 90
NiO = 4 mg/L 66 84 84 83
NiO = 7 mg/L 89 91 88 88
NiO = 10 mg/L 85 88 85 90
ZnO = 1 mg/L 64 86 74 80
ZnO = 3 mg/L 72 90 89 88
ZnO = 5 mg/L 92 93 90 93
Table 5: Effects of some nano-sized metal oxides on the removal of CODdis, total phenol, TAAs and color at 25°C, after 150 min ultrasound time, at a frequency of 35 kHz, at a power of 640 W and at pH=5.4 (n=3, mean values).