Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun 130021, China; National and Local Joint Engineering Laboratory for Petrochemical Contaminated Site Control and Remediation Technology, Jilin University, Changchun 130021, China.
Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China; Jilin Provincial Key Laboratory of Water Resources and Environment, Jilin University, Changchun 130021, China; National and Local Joint Engineering Laboratory for Petrochemical Contaminated Site Control and Remediation Technology, Jilin University, Changchun 130021, China.
J Environ Sci (China). 2020 Apr;90:375-384. doi: 10.1016/j.jes.2020.01.001. Epub 2020 Jan 13.
In this study, sodium tripolyphosphate (STPP) was used to promote the removal of organic pollutants in a zero-valent copper (ZVC)/O system under neutral conditions for the first time. 20 mg/L p-nitrophenol (PNP) can be completely decomposed within 120 min in the ZVC/O/STPP system. The PNP degradation process followed pseudo-first-order kinetics and the degradation rate of PNP gradually increased upon the decreasing ZVC particle size. The optimal pH of the reaction system was 5.0. Our mechanism investigation showed that Cu generated by ZVC corrosion was the main reducing agent for the activation of O to produce ROS. ·OH was identified as the only ROS formed during the degradation of PNP and its production pathway was the double-electron activation of O (O→HO→·OH). In this process, STPP did not only promote the release of Cu through its complexation, but also promoted the production of ·OH by reducing the redox potential of Cu/Cu. In addition, we could initiate and terminate the reaction by controlling the pH. At pH < 8.1, ZVC/O/STPP could continuously degrade organic pollutants; at pH > 8.1, the reaction was terminated. STPP was recycled to continuously promote the corrosion of ZVC and O activation as long as the pH was <8.1. This study provided a new and efficient way for O activation and organic contaminants removal.
在这项研究中，首次使用三聚磷酸钠（STPP）在中性条件下促进零价铜（ZVC）/O 体系中有机污染物的去除。在 ZVC/O/STPP 体系中，20mg/L 的对硝基苯酚（PNP）可在 120min 内完全分解。PNP 的降解过程遵循拟一级动力学，随着 ZVC 颗粒尺寸的减小，PNP 的降解速率逐渐增加。反应体系的最佳 pH 值为 5.0。我们的机理研究表明，ZVC 腐蚀产生的 Cu 是激活 O 产生 ROS 的主要还原剂。·OH 被鉴定为 PNP 降解过程中形成的唯一 ROS，其生成途径是 O 的双电子激活（O→HO→·OH）。在这个过程中，STPP 不仅通过络合作用促进 Cu 的释放，而且通过降低 Cu/Cu 的氧化还原电位来促进·OH 的生成。此外，我们可以通过控制 pH 值来启动和终止反应。在 pH<8.1 时，ZVC/O/STPP 可以连续降解有机污染物；在 pH>8.1 时，反应终止。只要 pH<8.1，STPP 就可以被回收以连续促进 ZVC 的腐蚀和 O 的激活。本研究为 O 激活和有机污染物去除提供了一种新的、有效的方法。
