State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China; Nanjing Innovation Center for Environmental Protection Industry Co., Ltd., Nanjing, 211102, PR China.
State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China.
Chemosphere. 2022 Oct;305:135400. doi: 10.1016/j.chemosphere.2022.135400. Epub 2022 Jun 18.
In this work, p-Nitrophenol (p-NP) was electro-chemically removed by using a prepared CoO/Ti cathode and a BDD anode to achieve the simultaneous reduction of total organic carbon (TOC), total nitrogen (TN) and toxicity. The prepared CoO/Ti cathode showed higher electro-activity than the Ti cathode towards p-NP reduction with the removal rate higher than 90.6% but without mineralization. The electro-oxidation removed 84.3% of TOC but none of TN. To develop an optimized process for mineralization and TN removal during p-NP electrolysis, the combination of electro-oxidation and electro-reduction were evaluated by using a dual-chamber cell and a single-chamber cell, respectively. As a result of the re-oxidation and re-reduction in the single-chamber cell, the typically used mode of the simultaneous redox, showed a lower removal of TOC and TN than the combination processes as well as an increased toxicity. The TN removal for both combined modes (21.0%-32.9%) was all higher than that of the mode of reduction because the produced inorganic nitrogen such as ammonia and nitrate could be partially oxidized or reduced to nitrogen gas. The results suggested that the combination process could significantly improve the mineralization and TN reduction for p-NP removal, accompanied with 60.3% decrease of acute toxicity for the reduction after oxidation mode.
在这项工作中，使用制备的 CoO/Ti 阴极和 BDD 阳极通过电化学方法去除对硝基苯酚（p-NP），以实现总有机碳（TOC）、总氮（TN）和毒性的同时还原。与 Ti 阴极相比，制备的 CoO/Ti 阴极对 p-NP 还原具有更高的电活性，去除率高于 90.6%，但没有矿化。电氧化去除了 84.3%的 TOC，但没有去除任何 TN。为了在 p-NP 电解过程中开发矿化和 TN 去除的优化工艺，分别使用双室电池和单室电池评估了电氧化和电还原的组合。由于在单室电池中发生再氧化和再还原，通常用于同时氧化还原的模式表现出比组合过程更低的 TOC 和 TN 去除率，以及更高的毒性。两种组合模式（21.0%-32.9%）的 TN 去除率均高于还原模式，因为产生的无机氮（如氨和硝酸盐）可以部分氧化或还原为氮气。结果表明，组合工艺可以显著提高 p-NP 去除的矿化和 TN 还原，同时在氧化后还原模式下，急性毒性降低了 60.3%。
