标题: Stepwise H*-Mediated and Non-H* Reduction Processes for Highly Selective Transformation of Nitrate to Nitrogen Gas Using a ZVAl-Based Material

作者: Li, Y (Li, Yan); Liu, WJ (Liu, Wenjie); Zhu, H (Zhu, Hua); Cui, JX (Cui, Jiaxin); Xu, T (Xu, Tao); Zhao, Y (Zhao, Ying); Mao, XH (Mao, Xuhui)

来源出版物: ENVIRONMENTAL SCIENCE & TECHNOLOGY  卷: 59  期: 6  页: 3286-3296  DOI: 10.1021/acs.est.4c10943  Early Access Date: FEB 2025  Published Date: 2025 FEB 6  

摘要: Improving the reduction efficiency and N2 selectivity is important for nitrate decontamination. A novel ternary ball-milled Al-Cu-AC material is reported to achieve a highly selective reduction of nitrate to N2. The reduction process, driven by the continuous dissolution of zero-valent aluminum (ZVAl), demonstrated a stepwise reduction scheme. The interesting shift in the electron-donating pathways was ascribed to the spontaneous change in the microenvironmental pH from neutral to alkaline. The Al-Cu-AC (1:1:5 mass ratio) material completely removed 30 mg/L of NO3 --N over a wide pH range (5-9), achieving over 83% TN removal and N2-selectivity, without detectable copper leaching. The atomic hydrogen (H*)-mediated reduction occurring on the Cu component was proven to be crucial for the fast transformation from NO3 - to NO2 -, while the non-H* reduction process was dominated by the electrochemical reduction of NO2 - to N2 on the AC cathode of Al || AC microgalvanic cells formed in the material. The primary reduction route from NO3 - to N2 was identified as the *NOH pathway, and the superiority of the Al-Cu-AC material toward nitrate reduction was verified with actual wastewater. This study revealed how microenvironmental pH influenced the electron-donating pathways of ZVAl and provides a new approach to maximize the performance of zero-valent metals.

作者关键词: zero-valent aluminum; nitrate reduction; nitrogenselectivity; microgalvanic cells; atomic hydrogenreduction

KeyWords Plus: ZERO-VALENT IRON; ELECTROCATALYTIC REDUCTION; AQUEOUS NITRATE; REMOVAL; MECHANISM; ALUMINUM; WATER; REACTIVITY; CATALYST; SURFACE

地址: [Li, Yan; Liu, Wenjie; Zhu, Hua; Xu, Tao; Mao, Xuhui] Wuhan Univ, Sch Resources & Environm Sci, Wuhan 430079, Peoples R China.

[Cui, Jiaxin] Changjiang Survey Planning Design & Res Co Ltd, Wuhan 430010, Peoples R China.

[Zhao, Ying] Chinese Res Inst Environm Sci, State Environm Protect Key Lab Simulat & Control G, Beijing 100012, Peoples R China.

通讯作者地址: Mao, XH (通讯作者)，Wuhan Univ, Sch Resources & Environm Sci, Wuhan 430079, Peoples R China.

电子邮件地址: clab@whu.edu.cn

影响因子：10.9