h-NPAC@AC@GR电极制备及降解焦化废水

Preparation of the h-NPAC@AC@GR Electrode and Its Degradation of Coking Wastewater

摘要: 焦化废水可生化性差且毒性显著，会直接威胁人体生命健康。该废水水质组分繁杂，酚类、氰化物、苯类物质与氨氮等多种毒害污染物大量存在，若未经达标处理直接排放，极易造成水体重度污染，扰乱自然生态系统稳定。开发高效可行的焦化废水处理技术，现已成为全球环境领域科研人员的重点研究方向。电芬顿氧化工艺绿色安全，反应过程无次生污染物生成，因此得到诸多学者的深入探究。本研究采用电芬顿氧化体系处理焦化废水，以h-NPAC@AC@GR复合电极为反应电极，系统探究电极面积、Fe²⁺浓度、电流密度及反应体系pH对废水中COD去除效率的作用规律，并同步测试电极的循环使用稳定性。实验结果显示，污染物降解效率会随反应时长延长持续提升；COD去除效率与电极面积呈正向相关；体系pH = 3、电流密度25 mA/cm²、Fe²⁺浓度0.7 mM为最优运行参数，该条件下COD去除效率最高可达86%。

Abstract: Coking wastewater exhibits poor biodegradability and high toxicity, posing a direct threat to human health. This type of wastewater features complex water quality components, containing abundant toxic pollutants such as phenols, cyanides, benzene substances and ammonia nitrogen. If discharged directly without reaching discharge standards, it will easily lead to severe water pollution and disrupt the stability of natural ecosystems. Developing efficient and feasible treatment technologies for coking wastewater has become a key research focus for environmental researchers worldwide. As an environmentally friendly process that produces no secondary contaminants during reactions, the electro-Fenton oxidation technology has attracted in-depth investigations from numerous scholars. In this study, an electro-Fenton oxidation system was constructed to treat coking wastewater, with h-NPAC@AC@GR composite electrodes adopted as reaction electrodes. The effects of electrode area, Fe²⁺ concentration, current density and system pH on the COD removal efficiency of wastewater were systematically explored, and the cycling stability of electrodes was simultaneously evaluated. Experimental results demonstrate that the degradation efficiency of pollutants continuously improves with the extension of reaction time; COD removal efficiency is positively correlated with electrode area. The optimal operating parameters are pH of 3, current density of 25 mA/cm² and Fe²⁺ concentration of 0.7 mM, under which the maximum COD removal efficiency reaches 86%.