Study on Degradation of p-Nitrophenol in Aqueous Solution by Ultrasound

The study on degradation of p-Nitrophenol (p-Np) in aqueous solution by ultrasound process was given in this paper. The influence on degradation and laws by several factors, which included the initial concentration, the initial pH, the energy density, the reaction temperature and the presence of saturated gas, were discussed. The results showed that the initial concentration, the initial pH, the energy density were the main factors. The p-Np of lower concentration can be degraded in lower pH and higher energy density. When the initial pH value ranged from 11 to 3, the degradation efficiency of p-Np varied from 14.8% to 50.1%; when the energy density decreased to 3.13 W/mL from 1.25 W/mL, the degradation efficiency of p-Np decreased to 8.76% from 50.1%. Moreover, within the concentration range which was studied, the reaction followed the first-order kinetic reaction, when the initial concentration was over 60 mg/L; the tendency which was the first-order rate constant with the augment of initial concentration was not obvious sufficiently. Aerating into the solution contributes the degradation of p-Np, but the efficiency was not obvious, and the variation of temperature has almost no influence on the degradation of p-Np.