State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, PR China.
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science & Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
J Hazard Mater. 2022 Jan 5;421:126673. doi: 10.1016/j.jhazmat.2021.126673. Epub 2021 Jul 17.
This study applied a mineral material of FeS to activate sulfite for efficient degradation of TTC in the presence of Cu(II) based on the identified complexation mechanism through UV-Vis spectra, FTIR spectroscopy and DFT calculation. pH plays an important role in TTC degradation and the initial pH of 6 and 7 were the divide in the contributions of FeS/sulfite oxidation and complex-precipitation. TTC-Cu(II) exhibits a superior promoting effect on the TTC degradation in FeS/sulfite system due to the improvement of TTC electron transfer reactivity and Fe(II) dissolution from FeS. Moreover, the formation of Cu(I) improved the recycling of Fe(II) from Fe(III). Dissolved oxygen-dependent free radicals' generation was confirmed, and TTC degradation was mainly attributed to SO and ·OH. The characterization of FeS surface through XPS, XRD, SEM-EDS, Fe(II) deactivation tests, together with the comparison of pseudo-first-order rate constants for TTC degradation by FeS and ferrous ion supported the important role of surface and dissolved Fe(II) in sulfite activation. Furthermore, reasonable degradation pathways of TTC have been proposed according to the detected products by LC-MS. This work highlights the important role of pH, DO and Cu(II) complexation in sulfite activation and TTC degradation, furnishing theoretical support for further relevant studies.
本研究应用 FeS 矿物材料激活亚硫酸盐，在 Cu(II)存在下通过 UV-Vis 光谱、傅里叶变换红外光谱和 DFT 计算鉴定的络合机制，实现 TTC 的有效降解。pH 值在 TTC 降解中起着重要作用，初始 pH 值为 6 和 7 是 FeS/亚硫酸盐氧化和络合沉淀贡献的分水岭。TTC-Cu(II)在 FeS/亚硫酸盐体系中对 TTC 降解表现出优异的促进作用，这是由于 TTC 电子转移反应性的提高和 FeS 中 Fe(II)的溶解。此外，Cu(I)的形成提高了 Fe(II)从 Fe(III)中的循环利用。通过 XPS、XRD、SEM-EDS 对 FeS 表面进行表征、Fe(II)失活试验以及 FeS 和二价铁离子降解 TTC 的拟一级速率常数的比较，证实了溶解氧依赖性自由基的生成，TTC 降解主要归因于 SO 和·OH。根据 LC-MS 检测到的产物，提出了 TTC 的合理降解途径。这项工作强调了 pH 值、DO 和 Cu(II)络合在亚硫酸盐活化和 TTC 降解中的重要作用，为进一步的相关研究提供了理论支持。
