Abstract:

Titanium dioxide was prepared and used to explore its synergistic effect with ultrasonic on degradation of acephate aqueous solution at low concentration. The degradation rate of acephate was investigated with respect to temperature, pH, ultrasonic intensity, titanium dioxide amount and various combinations of ultrasonic intensity and titanium dioxide amount. The degradation rate of acephate increased as the ultrasonic treatment time increased up to 1 h and the temperature increased from 5 ℃ to 20 ℃. An acidic environment of pH 3 was favorable to the degradation of acephate. Within a certain range, titanium dioxide amount was positively related to the degradation rate of acephate. An ultrasonic intensity of 40 W/cm2 was conducive to increasing the degradation rate of acephate. Moreover, ultrasonic and titanium dioxide could synergistically degrade acephate. A degradation rate of 78.3% was observed for 2 mg/L acephate aqueous solution at 20 ℃ and pH 3.0 with the addition of titanium dioxide at 0.6 g/L after 50 min ultrasonic treatment at a frequency of 25 kHz and an intensity of 40 W/cm2.

Key words: titanium dioxide, ultrasonic, acephate, degradation