Chen Wensi, Rigby Kali, Lim Hyun Jeong, Kim David J, Kim Jae-Hong
Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511, United States.
Zachry Department of Civil and Environmental Engineering, Texas A&M University, College Station, Texas 77843, United States.
Environ Sci Technol. 2024 Jul 16;58(30):13552-61. doi: 10.1021/acs.est.4c03189.
Electrochemical advanced oxidation is an appealing point-of-use groundwater treatment option for removing pollutants such as 1,4-dioxane, which is difficult to remove by using conventional separation-based techniques. This study addresses a critical challenge in employing electrochemical cells in practical groundwater treatment─electrode stability over long-term operation. This study aims to simulate realistic environmental scenarios by significantly extending the experimental time scale, testing a flow-through cell in addition to a batch reactor, and employing an electrolyte with a conductivity equivalent to that of groundwater. We first constructed a robust titanium suboxide nanotube mesh electrode that is utilized as both anode and cathode. We then implemented a pulsed electrolysis strategy in which reactive oxygen species are generated during the anodic cycle, and the electrode is regenerated during the cathodic cycle. Under optimized conditions, single-pass treatment through the cell (effective area: 2 cm) achieved a remarkable 65-70% removal efficiency for 1,4-dioxane in the synthetic groundwater for over 100 h continuous operation at a low current density of 5 mA cm and a water flux of 6 L m h. The electrochemical cell and pulse treatment scheme developed in this study presents a critical advancement toward practical groundwater treatment technology.
电化学高级氧化是一种有吸引力的现场地下水处理选择，用于去除诸如1,4 - 二恶烷等污染物，这些污染物难以通过传统的基于分离的技术去除。本研究解决了在实际地下水处理中使用电化学电池的一个关键挑战——长期运行中的电极稳定性。本研究旨在通过显著延长实验时间尺度、除了测试间歇式反应器外还测试流通池以及使用电导率与地下水相当的电解质来模拟实际环境场景。我们首先构建了一种坚固的低价钛氧化物纳米管网状电极，该电极用作阳极和阴极。然后我们实施了一种脉冲电解策略，即在阳极循环期间产生活性氧物种，在阴极循环期间使电极再生。在优化条件下，通过该电解池（有效面积：2平方厘米）进行单程处理，在5毫安/平方厘米的低电流密度和6升/平方米·小时的水通量下，对合成地下水中的1,4 - 二恶烷进行超过100小时的连续运行，去除效率达到了显著的65 - 70%。本研究中开发的电化学电池和脉冲处理方案是朝着实用地下水处理技术迈出的关键一步。
