超声波降解水溶液中甲醛的研究

Study on Ultrasonic Degradation of Formaldehyde in Aqueous Solution

研究了超声波场降解水溶液中甲醛的行为,并探讨了反应动力学方程。实验表明,超声波降解甲醛能够达到较高的降解率,但反应速率较低。甲醛的降解率随超声作用时间的延长而直线上升,在频率200kHz、功率200W的超声场作用4h后可达到90％左右。反应体系的最佳温度为30℃。在碱性区域甲醛的降解率出现大幅度的增加。溶液中溶解气体的种类对降解反应有一定的影响,降解速率顺序为O_3>空气>N_2。超声波降解甲醛的反应符合一级反应动力学模式。

Sonochemical degradation of formaldehyde in aqueous solution has been studied, and the kinetic equation of sonolysis has also been discussed. The results showed that the removal efficiency of this action was high, but reaction rate was low. 90% of removal efficiency was obtained after being irradiated for 240 min, and the initial concentration did effect on degradation. The optimum reaction temperature for this system was about 30!. The more satisfactory efficiency could be obtained when the pH value was controlled at above 13. Dissolved gas did also effect on the reaction rate, the sequence of the reaction rates was O3>air >N2, and the kinetic equation was conformed to first order reaction.