Jia Yongying, Li Hongguang, Zhao Haiqian, Zhang Guole, Zhang Zhuangzhuang, Zhang Xiaolong, Zhou Wei
School of Mechanical Science and Engineering, Northeast Petroleum University, Daqing, Heilongjiang, 163318, China.
School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, Jiangsu, 215009, China.
J Environ Manage. 2024 Apr;357:120823. doi: 10.1016/j.jenvman.2024.120823. Epub 2024 Apr 6.
Fe(II) regeneration plays a crucial role in the electro-Fenton process, significantly influencing the rate of ·OH formation. In this study, a method is proposed to improve Fe(II) regeneration through N-doping aimed at enhancing the adsorption capacity of the activated carbon cathode for Fe(III). N-doping not only enriched the pore structure on the surface of activated carbon, providing numerous adsorption sites, but also significantly increased the adsorption energy for Fe(III). Among the types of nitrogen introduced, pyridine-N exhibited the most substantial enhancement effect, followed by pyrrole-N, while graphite-N showed a certain degree of inhibition. Furthermore, N-doping facilitated the adsorption of all forms of Fe(III) by activated carbon. The adsorption and electrosorption rates of the NAC-900 electrode for Fe(III) were 30.33% and 42.36%, respectively. Such modification markedly enhanced the Fe/Fe cycle within the electro-Fenton system. The NAC-900 system demonstrated an impressive phenol degradation efficiency of 93.67%, alongside the lowest electricity consumption attributed to the effective "adsorption-reduction" synergy for Fe(III) on the NAC-900 electrode. Compared to the AC cathode electro-Fenton system, the degradation efficiency of the NAC-900 cathode electro-Fenton system at pH = levels ranging from 3 to 5 exceeded 90%; thus, extending the pH applicability of the electro-Fenton process. The degradation efficiency of phenol using the NAC-900 cathode electro-Fenton system in various water matrices approached 90%, indicating robust performance in real wastewater treatment scenarios. This research elucidates the impact of cathodic Fe(III) adsorption on Fe(II) regeneration within the electro-Fenton system, and clarifies the influence of different N- doping types on the cathodic adsorption of Fe(III).
亚铁（Fe(II)）再生在电芬顿过程中起着关键作用，对·OH的生成速率有显著影响。本研究提出了一种通过氮掺杂来改善Fe(II)再生的方法，旨在提高活性炭阴极对Fe(III)的吸附能力。氮掺杂不仅丰富了活性炭表面的孔隙结构，提供了大量吸附位点，还显著提高了对Fe(III)的吸附能。在引入的氮类型中，吡啶氮表现出最显著的增强效果，其次是吡咯氮，而石墨氮则表现出一定程度的抑制作用。此外，氮掺杂促进了活性炭对各种形态Fe(III)的吸附。NAC - 900电极对Fe(III)的吸附率和电吸附率分别为30.33%和42.36%。这种改性显著增强了电芬顿系统内的Fe/Fe循环。NAC - 900系统表现出令人印象深刻的93.67%的苯酚降解效率，同时由于NAC - 900电极上对Fe(III)有效的“吸附 - 还原”协同作用，电耗最低。与AC阴极电芬顿系统相比，NAC - 900阴极电芬顿系统在pH值为3至5的范围内降解效率超过90%；从而扩展了电芬顿过程的pH适用范围。在各种水基质中使用NAC - 900阴极电芬顿系统降解苯酚的效率接近90%，表明在实际废水处理场景中性能强劲。本研究阐明了阴极对Fe(III)的吸附对电芬顿系统内Fe(II)再生的影响，并明确了不同氮掺杂类型对阴极对Fe(III)吸附的影响。
