Taping into the super power and magic appeal of ultrasound coupled with EDTA on degradation of 2,4,6-TCP by Fe0 based advanced oxidation processes
Taping into the super power and magic appeal of ultrasound coupled with EDTA on degradation of 2,4,6-TCP by Fe0 based advanced oxidation processes
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利用超声波与 EDTA 结合的超强威力和魔力，以 Fe0 为基础的高级氧化工艺降解 2,4,6-TCP
DOI：
10.1016/j.chemosphere.2021.132650
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发表时间：
2021-12-12
期刊：
影响因子：
8.8
通讯作者：
Zheng, Huaili
中科院分区：
文献类型：
--
作者：
Liu, Bingzhi;Pan, Tingyu;Zheng, Huaili
氯酚是一种用途广泛的有机化合物，近年来其引起的环境和健康问题日益严重。本研究以2，4，6-三氯苯酚（2，4，6-TCP）为目标污染物，采用超声（US）强化零价铁（Fe-0）/EDTA/空气体系（FEA），即US/FEA对2，4，6-TCP进行去除。考察了EDTA浓度、Fe-0投加量、US功率、pH值和污染物浓度等单因素实验条件对2，4，6-TCP去除效果的影响，确定了最佳反应条件。探讨了超声/FEA产生活性氧的机理。通过对中间产物的测定和分析，探讨了2，4，6-TCP在US/FEA中的降解过程和去除机理。结果表明，超声能持续活化和更新Fe-0表面，加速其氧化和腐蚀过程，从而持续稳定地产生足量的Fe 2+和Fe 3+。超声空化效应可以降低O2-活化反应的难度，促进H2 O2的产生。EDTA的加入使该体系具有较宽的pH应用范围，在中性和碱性条件下的性能也较为上级。超声波/有限元分析的活性氧包括.OH、O-2（中心点-）和Fe（IV），其中Fe（IV）是2，4，6-TCP去除的主要贡献者。此外，2，4，6-TCP的降解有脱氯和苯环开环两个过程.首先，2，4，6-TCP脱氯并降解为苯酚。然后苯酚被开环降解为小分子酸，最后完全矿化为CO2和H2O。超声/有限元技术是一种高效降解有机物和深度净化环境的新技术。
Chlorophenol is a widely used organic compound, and the environmental and health problems caused by it have being worsened in recent years. This study used 2,4,6-trichlorophenol (2,4,6-TCP) as the target pollutant, and employed ultrasound (US) enhanced zero-valent iron (Fe-0)/EDTA/air system (FEA), namely US/FEA, to remove 2,4,6-TCP. The influence of single factor experimental conditions such as EDTA concentration, Fe-0 dosage, US power, pH and pollutant concentration on the removal efficiency of 2,4,6-TCP was investigated, and the optimal reaction conditions were determined. The mechanism of reactive oxygen species (ROS) produced by US/FEA was explored. The degradation process and removal mechanism of 2,4,6-TCP in the US/FEA were discussed through the determination and analysis of intermediate products. The results showed that US could continuously activate and renew the Fe-0 surface, accelerate its oxidation and corrosion process, and then continuously and stably produce sufficient amounts of Fe2+ and Fe3+. Ultrasonic cavitation effect could reduce the difficulty of O-2 activation reaction, and promote the production of sufficient H2O2. The addition of EDTA made the system have a wide range of pH applications, and its performance under neutral and alkaline conditions was also superior. The ROS of US/FEA included .OH, O-2(center dot-) and Fe(IV), where Fe(IV) was the main contributor to the removal of 2,4,6-TCP. In addition, the degradation of 2,4,6-TCP had two processes including dechlorination and benzene ring opening. First, 2,4,6-TCP was dechlorinated and degraded into phenol. And then, phenol was degraded into small molecular acids by ring-opening, and finally it was mineralized into CO2 and H2O completely. US/FEA is a promising technology for high-efficiency degradation of organic matter and deep environmental purification.