The research on developing a purification technology for 2,4-dichlorophenol (2,4-DCP) polluted water with high efficiency and the low energy consumption is crucial for achieving several Sustainable Development Goals (SDGs). In order to achieve these goals, MWCNTs-Pd/Fe nanocomposites were prepared by Fe nanoparticles modified with multi-walled carbon nanotubes (MWCNTs) and palladium (Pd) in the presence of ultrasonic irradiation. The MWCNTs-Pd/Fe nanocomposites were characterized by using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and X-Ray Diffraction (XRD), and others. Characterization results confirmed that the MWCNTs-Pd/Fe was successfully prepared, with the particle size of 80 nm and the specific surface area of 89.5 m/g confirmed. We studied the reductive dechlorination of 2,4-Dichlorophenol (2,4-DCP) by MWCNTs-Pd/Fe nanocomposites under different conditions, and the optimized experimental results were found when the Pd loading was 0.4 %, the pH was 3, and the temperature was 30 °C. The phenol yield increased from 76.5 % (without ultrasonic irradiation) to 92.3 % (with ultrasonic irradiation) in 300 min and the 2,4-DCP removal rate reached 98.7 % under the optimal conditions. Therefore, ultrasonic irradiation enhanced the performance of MWCNTs-Pd/Fe nanocomposites for 2,4-DCP removal. We also established the degradation mechanism of chlorophenol by analyzing the intermediates, and proposed the degradation kinetics model. The degradation of 2,4-DCP followed the pseudo-first-order kinetics with the rate constant of 0.05988 min. Also, this study demonstrated the potential of using ultrasonic irradiation to improve the properties and recovery of MWCNTs-Pd/Fe nanocomposites, contributing to achievement of the Sustainable Development Goals (SDGs), including SDG-3, SDG-6.

中文翻译：

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超声辐照下制备的MWCNTs-Pd/Fe纳米复合材料还原脱氯2,4-二氯苯酚


研究开发高效、低能耗的2,4-二氯苯酚（2,4-DCP）污染水净化技术对于实现多项可持续发展目标（SDG）至关重要。为了实现这些目标，通过多壁碳纳米管（MWCNT）和钯（Pd）修饰的Fe纳米颗粒在超声波照射下制备了MWCNTs-Pd/Fe纳米复合材料。通过扫描电子显微镜 (SEM)、透射电子显微镜 (TEM) 和 X 射线衍射 (XRD) 等手段对 MWCNTs-Pd/Fe 纳米复合材料进行了表征。表征结果证实成功制备了MWCNTs-Pd/Fe，粒径为80 nm，比表面积为89.5 m/g。我们研究了不同条件下MWCNTs-Pd/Fe纳米复合材料对2,4-二氯苯酚(2,4-DCP)的还原脱氯，发现当Pd负载量为0.4%、pH为3、温度为 30°C。在最佳条件下，300 min内苯酚收率从76.5%（无超声波照射）提高到92.3%（有超声波照射），2,4-DCP去除率达到98.7%。因此，超声波照射增强了MWCNTs-Pd/Fe纳米复合材料去除2,4-DCP的性能。我们还通过分析中间体建立了氯酚的降解机理，并提出了降解动力学模型。 2,4-DCP 的降解遵循准一级动力学，速率常数为 0.05988 分钟。 此外，这项研究还证明了利用超声波辐照改善 MWCNT-Pd/Fe 纳米复合材料的性能和回收率的潜力，有助于实现可持续发展目标 (SDG)，包括 SDG-3、SDG-6。