The consistent presence of p-chloronitrobenzene (p-CNB) in groundwater has raised concerns regarding its potential harm. In this study, we developed a biocathode-anode cascade system in a permeable reactive barrier (BACP), integrating biological electrochemical system (BES) with permeable reactive barrier (PRB), to address the degradation of p-CNB in the groundwater. BACP efficiently accelerated the formation of biofilms on both the anode and cathode using the polar periodical reversal method, proving more conducive to biofilm development. Notably, BACP demonstrated a remarkable p-CNB removal efficiency of 94.76 % and a dechlorination efficiency of 64.22 % under a voltage of 0.5 V, surpassing the results achieved through traditional electrochemical and biological treatment processes. Cyclic voltammetric results highlighted the primary contributing factor as the synergistic effect between the bioanode and biocathode. It is speculated that this system primarily relies on bioelectrocatalytic reduction as the predominant process for p-CNB removal, followed by subsequent dechlorination. Furthermore, electrochemical and microbiological tests demonstrated that BACP exhibited optimal electron transfer efficiency and selective microbial enrichment ability under a voltage of 0.3–0.5 V. Additionally, we investigated the operational strategy for initiating BACP in engineering applications. The results showed that directly introducing BACP technology effectively enhanced microbial film formation and pollutant removal performance.

中文翻译：

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PRB 中的生物阴极-阳极复叠系统：地下水中对氯硝基苯的高效降解


地下水中持续存在的对氯硝基苯 （p-CNB） 引起了人们对其潜在危害的担忧。在这项研究中，我们在可渗透反应屏障 （BACP） 中开发了一种生物阴极-阳极级联系统，将生物电化学系统 （BES） 与可渗透反应屏障 （PRB） 相结合，以解决地下水中 p-CNB 的降解问题。BACP 使用极性周期反转方法有效地加速了阳极和阴极上生物膜的形成，证明更有利于生物膜的形成。值得注意的是，BACP 在 0.5 V 电压下表现出 94.76% 的显著 p-CNB 去除效率和 64.22% 的脱氯效率，超过了传统电化学和生物处理工艺所取得的结果。循环伏安结果突出了主要影响因素是生物阳极和生物阴极之间的协同效应。据推测，该系统主要依靠生物电催化还原作为去除 p-CNB 的主要过程，然后是随后的脱氯。此外，电化学和微生物测试表明，BACP 在 0.3-0.5 V 的电压下表现出最佳的电子转移效率和选择性微生物富集能力。此外，我们还研究了在工程应用中启动 BACP 的操作策略。结果表明，直接引入 BACP 技术可有效增强微生物膜的形成和污染物去除性能。