【摘要】 研究了超声条件下四氯化碳与甲基橙混合水溶液的协同降解规律。超声能够使水中的四氯化碳迅速降解,而甲基橙水溶液的单独超声降解效果极差,但四氯化碳存在时其超声降解效率能够得到极大地增强。结果表明,使用40 kHz,0.272 W·cm-2超声作用6 min,四氯化碳饱和水溶液(5.23 mmol·L-1)降解率达到91.83%,24 mg·L-1甲基橙水溶液降解率只有0.85%,而处理二者混合水溶液时甲基橙降解率达到79.08%。在实验条件下,当四氯化碳初始浓度大于1.04 mmol·L-1时甲基橙超声/四氯化碳降解表现为零级反应过程,而低于1.04 mmol·L-1为一级反应过程;超声频率增大、温度降低降解速率增大;降解速率常数与超声声强成正比关系;空化气体的影响顺序是氧气>没有鼓泡>氮气。甲基橙超声/四氯化碳降解过程中起主要作用的是氯基自由基。更多还原

【Abstract】 The synergistic effect of ultrasonic decomposition of CCl4 and methyl orange(MO) simulated wastewater was investigated.The sonochemical degradation of CCl4 in water is very rapid,while the ultrasonic degradation of MO aqueous solution is very poor.But the ultrasonic degradation of MO can be drastically enhanced in the presence of CCl4.After irradiation for 6 min by using 40 kHz,0.272 W cm 2 ultrasound,the degradation ratios of CCl4 saturated aqueous solution(5.23 mmol L 1) and 24 mg L 1 MO are 91.83% and 0.85%,respectively.At the same time,the ultrasonic degradation of MO is 79.08% in the presence of CCl4.Under experimental conditions,if the initial concentration of CCl4 is greater than 1.04 mmol L 1,the sonochemical degradation of MO behaves as a zero-order reaction in kinetics,otherwise,the reaction is a first-order reaction.The sonochemical decomposition efficiency of MO by adding CCl4 increases with the increase of ultrasonic frequency,and the decrease of temperature,and the degradation rate constant of MO is in direct proportion to ultrasonic intensity.The effects of cavitation gases on the MO degradation are listed in the following decreasing order: oxygen >no saturation gas> nitrogen.The degradation mechanism of MO by using US/CCl4 is attributed to chlorine-based free radicals.更多还原