State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Centre for Environmental Risk Management & Remediation of Soil & Groundwater, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Centre for Environmental Risk Management & Remediation of Soil & Groundwater, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
J Hazard Mater. 2022 Feb 5;423(Pt B):127199. doi: 10.1016/j.jhazmat.2021.127199. Epub 2021 Sep 11.
Delivering persulfate (PS) efficiently into clay is an unsolved challenge. This study proposes a novel strategy with enhanced electrokinetically -delivery PS into clay by using PS for continuously flushing cathode to inhibit water electrolysis at cathode electrode. On this basis, a novel approach of heating soil by alternating current (AC) was used to thermally activate PS in situ. Results show that the mass transfer efficiency of PS by electroosmotic flow is about 20 times that by electromigration. Moreover, when PS was added in the anode chamber, using PS solution continuously flushing cathode created a relatively balanced the influent and effluent flow rates, significantly improving the mass transfer efficiency of PS. Compared to using NaNO solution flushing, a significant increase of 51.7% was achieved, reaching 78.8%, for the phenanthrene (PHE) average degradation rate in soil cell. In contrast, the best overall PHE removal rate was observed, reaching 87.8%, by a cycle strategy of enhanced electrokinetically -delivered PS followed by AC heating applied. Electron paramagnetic resonance spectroscopy analysis showed oxidative radicals (SO/•OH) were the major species responsible for enhanced PHE degradation. These results demonstrate that this cycle strategy is a viable method for remediation of polycyclic aromatic hydrocarbons in clay.
将过硫酸盐（PS）有效地输送到粘土中是一个尚未解决的挑战。本研究提出了一种新策略，通过使用 PS 连续冲洗阴极来抑制阴极电极处的水分解，从而增强电动力学输送 PS 进入粘土的能力。在此基础上，采用交流电（AC）加热土壤的新方法原位热激活 PS。结果表明，电渗流的 PS 传质效率约为电迁移的 20 倍。此外，当 PS 被添加到阳极室时，使用 PS 溶液连续冲洗阴极会产生相对平衡的进、出水流速率，从而显著提高 PS 的传质效率。与使用 NaNO3 溶液冲洗相比，土壤单元中菲的平均降解速率显著提高了 51.7%，达到 78.8%。相比之下，通过增强电动力学输送 PS 随后进行 AC 加热的循环策略，观察到最佳的整体菲去除率达到 87.8%。电子顺磁共振波谱分析表明，氧化自由基（SO4•/•OH）是增强菲降解的主要物质。这些结果表明，该循环策略是修复粘土中多环芳烃的一种可行方法。
