Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham Malaysia Campus, 43500, Semenyih, Selangor, Malaysia.
Department of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham Malaysia Campus, 43500, Semenyih, Selangor, Malaysia.
Chemosphere. 2018 Aug;204:101-108. doi: 10.1016/j.chemosphere.2018.04.014. Epub 2018 Apr 5.
Dicofol, an extensively used organochlorine pesticide and a recommended Stockholm convention persistent organic pollutant (POP) candidate is well known for its endocrine disruptive properties. The sonochemical degradation of Dicofol in aqueous media has been investigated using a 20-kHz probe type sonicator with power inputs from 150 to 450 W. The degradation rate was determined as a function of concentration of Dicofol, solution pH, bulk phase temperature, ultrasonic power density and HO addition. At optimum operating conditions, the pseudo-first-order degradation rate constant (k) was determined to be 0.032 min and the extent of degradation was found to be 86% within 60 min of ultrasound treatment. High performance liquid chromatography (HPLC) and Gas chromatography coupled with mass spectroscopy (GC-MS) analysis indicated the presence of degraded products. The obtained results of Dicofol degradation and control experiments in the presence of HO and radical scavenger test suggest thermal decomposition along with radical attack at bubble-vapor interface to be the dominant degradation pathway. Sonochemical treatment is effective and promising for successful removal of harmful pesticides such as Dicofol and superior removal efficiency for other POPs is expected in the near future with the successful implementation of ultrasound-based wastewater treatment.
三氯杀螨醇是一种广泛使用的有机氯农药，也是斯德哥尔摩公约推荐的持久性有机污染物（POP）候选物质，因其具有内分泌干扰特性而广为人知。本研究采用 20 kHz 探头式超声仪，在 150 至 450 W 的功率输入下，研究了三氯杀螨醇在水介质中的声化学降解情况。研究了三氯杀螨醇的浓度、溶液 pH 值、体相温度、超声功率密度和 HO 添加对降解速率的影响。在最佳操作条件下，确定了拟一级降解速率常数（k）为 0.032 min，超声处理 60 min 内的降解程度达到 86%。高效液相色谱（HPLC）和气相色谱-质谱联用（GC-MS）分析表明存在降解产物。三氯杀螨醇降解和 HO 存在及自由基清除实验的结果表明，热分解和气泡-蒸汽界面的自由基攻击是主要的降解途径。超声处理对于成功去除有害农药（如三氯杀螨醇）是有效的，在未来的不久，随着超声废水处理的成功实施，预计对于其他 POPs 的去除效率将更高。
