The sonochemical degradation in aqueous solution of methyl violet, chosen as a model of a basic dye, was studied. The ultrasonic degradation kinetics in water were found to be first-order and the degradation rate coefficient is 1.35×10-2 min-1 (R=0.9934, n=8) at 20±1℃. The influence of the initial concentrations, reaction temperature and the pH of medium on the ultrasonic decomposition of methyl violet were also investigated.

The phthalate esters such as DMP, DEP, DBP and DEHP in air, soil and plant samples in plastic film greenhouse were clean up with fine silica gel column and determined with HPLC. It was found that the concentrations of PEs in air and soil samples in plastic film greenhouse are much higher than those of contrast samples. But concentrations of PEs in plants in plastic film greenhouse are not remarkably affected by the pollution of air and soil.

A novel sonochemical method to directly prepare anatase nanocrystalline TiO2 has been established. TiO2 particles were synthesized by the hydrolysis of titanium tetraisopropyl in the presence of water and ethanol under high-intensity ultrasonic irradiation (20 KHz, 100 W/cm2 ) at 90℃ for 3 h. The product structure and the particle sizes were dependent upon the reaction temperature, the acidity of the medium and the reaction time. Characterization was accomplished using various different techniques, such as powder X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetry-differential thermal analysis (TG-DTA), and Fourier transform infrared (FT-IR) spectroscopy. The TEM images showed that the particles of TiO2 were columnar in shape and the average sizes were ～3×7 nm. The formation mechanism of nanocrystalline TiO2 under high-intensity ultrasonic irradiation was also discussed.