超声波降解天然地表水中新烟碱类农药。操作和环境条件的影响。
Sonochemical degradation of neonicotinoid pesticides in natural surface waters. Influence of operational and environmental conditions.
机构信息
Department of Chemical Engineering and Physical Chemistry, Area of Chemical Engineering, Faculty of Sciences, University of Extremadura, Avda. de Elvas, S/n, 06006, Badajoz, Spain.
Department of Chemical Engineering and Physical Chemistry, Area of Chemical Engineering, Faculty of Sciences, University of Extremadura, Avda. de Elvas, S/n, 06006, Badajoz, Spain.
出版信息
Environ Res. 2021 Jun;197:111021. doi: 10.1016/j.envres.2021.111021. Epub 2021 Mar 25.
Neonicotinoids sonochemical oxidation at high-frequency ultrasound (MHz range) has been carried out in ultrapure and natural surface-water matrices (river, reservoir and wastewater treatment plant effluent). To evaluate the influence of the operating variables, that is initial pollutant concentration, ultrasound frequency, ultrasound power, and pulse-stop time a Box-Behnken experimental design was planned. Optimal results were obtained using a frequency of 578 kHz, a power of 40 W L, with a pollutant concentration of 1 μM (for each pesticide), and using a pulse-stop time of 100 ms. The experimental data adjustment using the Langmuir-Hinshelwood heterogeneous kinetic model showed that neonicotinoids oxidation was carried out in the bubble-liquid interface by the attack of hydroxyl radicals. Experiments performed in the presence of radical scavengers, that is, methanol, ethanol and tert-butyl alcohol corroborated this reaction mechanism. The influence of some environmental conditions such as pH, presence of soluble inorganic species (Cl, SO, NO, HPO, HCO) and soluble organic species (humic acids content) were established. Finally, the aqueous matrix's influence was investigated for three natural surface water cases, and the results were rationalized according to the main water physicochemical characteristics.
在高频超声（MHz 范围内）下对新烟碱类物质进行声化学氧化，在超纯水和天然地表水基质（河流、水库和污水处理厂出水）中进行。为了评估操作变量的影响，即初始污染物浓度、超声频率、超声功率和脉冲停止时间，设计了 Box-Behnken 实验设计。使用 578 kHz 的频率、40 W·L 的功率、1 μM（每种农药）的污染物浓度和 100 ms 的脉冲停止时间，可获得最佳结果。使用 Langmuir-Hinshelwood 非均相动力学模型对实验数据进行调整表明，新烟碱类物质的氧化是在气泡-液相界面通过羟基自由基的攻击进行的。在自由基清除剂（甲醇、乙醇和叔丁醇）存在下进行的实验证实了这种反应机制。还确定了一些环境条件的影响，如 pH 值、可溶性无机物质（Cl、SO、NO、HPO、HCO）和可溶性有机物质（腐殖酸含量）的存在。最后，研究了三种天然地表水情况下水基质的影响，并根据主要水物理化学特性对结果进行了合理化。
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