超声波-热联合活化过硫酸盐氧化修复有机氯农药污染土壤

Degradation of Organochlorine Pesticides by Ultrasonic-Thermally Co-activated Persulfate in Soil System

采用超声-热联合活化过硫酸钠降解土壤中的六六六,考察了超声时间、温度、过硫酸钠投加量、初始pH对降解过程的影响。实验结果表明:超声时间为240min,温度为60℃,过硫酸钠投加量为0.2mol·L-1,初始pH为5.4时,α-六六六降解率可达95.96%;提高温度、增加过硫酸钠浓度以及延长超声时间均对α-六六六的降解效果有促进作用,改变反应初始pH对α-六六六的去除影响不大;酸性条件下α-六六六的去除效果略优于碱性条件和中性条件;超声波-热联合活化过硫酸盐对α-六六六的降解符合一级动力学模型,当温度在40~80℃时,其反应活化能为75.64kJ·mol-1。

Degradation of HCH by ultrasonic-thermally activated persulfate in soil system was studied in this work.The effect of various operating parameters, viz, the reaction time of ultrasound, reaction temperature,initial concentration of persulfate and initial pH were systematically examined.The results showed that α-HCH degradation rate can reach 95.96% under the condition （ultrasonic time 240min,temperature 60 ℃, PS dosage 0.2mol · L^-1, pH 5.4） （The removal effect was found to be improved with increasing the reaction time, the temperature and the initial concentration of persulfate, The initial pH of the system was found to be having no significant effect on the degradation process; and the removal of the α-HCH was slightly better under acidic system than neutral and alkaline system α- Further , oxidation reaction of α-HCH follows a pseudo-first-order kinetic model, the apparent activation energy achieved 75.64kJ · mol-1 when the temperature ranges from 40 to 80℃.