Yu Yu-Qing, Chen Xiang-Yu, Cai Quan-Hua, Huang Xin-Jue, Chen Man
College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Huan Jing Ke Xue. 2020 Jun 8;41(6):2746-2753. doi: 10.13227/j.hjkx.201911011.
Fenton reaction is a traditional method for the treatment of dye-containing wastewater. However, this process should be performed in a narrow pH range and requires large amounts of ferrous salt input, limiting its application. In this work, a robust iron complex bearing a cross-bridge cyclam ligand (Fe-cyclam) was successfully prepared. This complex could effectively activate HO to degrade rhodamine B at a pH range of 2-7. The Fe-cyclam/HO system was more effective in the degradation of rhodamine B than the Fenton reaction, when the input [Fe] was lower than 50 μmol·L. Moreover, in addition to rhodamine B, the Fe-cyclam/HO system was also capable of degrading dyes such as acid red 88, acid orange II, reactive red 24, and neutral red. This system was more efficient in the degradation of azo dyes than that of triphenylmethane dyes. The removal of rhodamine B remained higher than 90% in three cycle experiments, indicating the excellent stability of Fe-cyclam. The quenching experiments proved that the degradation of rhodamine B by Fe-cyclam/HO was a free-radical-control process. Meanwhile, the electron paramagnetic resonance captured the signals of high valent Fe-oxo species, indicating that Fe-oxo possibly mediated the degradation of rhodamine B in the Fe-cyclam/HO system. This work proves the potential application of Fe-cyclam/HO in the degradation of dyes in a practical environment.
芬顿反应是一种处理含染料废水的传统方法。然而，该过程需在较窄的pH范围内进行，且需要大量投入亚铁盐，这限制了其应用。在本研究中，成功制备了一种带有桥连环配体的稳定铁配合物（Fe-环戊二烯三胺）。该配合物能在pH值为2至7的范围内有效活化羟基自由基以降解罗丹明B。当铁的投入量低于50 μmol·L时，Fe-环戊二烯三胺/羟基自由基体系在降解罗丹明B方面比芬顿反应更有效。此外，除了罗丹明B，Fe-环戊二烯三胺/羟基自由基体系还能够降解酸性红88、酸性橙II、活性红24和中性红等染料。该体系对偶氮染料的降解比对三苯甲烷染料更高效。在三个循环实验中，罗丹明B的去除率仍高于90%，表明Fe-环戊二烯三胺具有出色的稳定性。猝灭实验证明，Fe-环戊二烯三胺/羟基自由基对罗丹明B的降解是一个自由基控制过程。同时，电子顺磁共振捕获到了高价铁氧物种的信号，表明铁氧可能介导了Fe-环戊二烯三胺/羟基自由基体系中罗丹明B 的降解。这项工作证明了Fe-环戊二烯三胺/羟基自由基在实际环境中染料降解方面的潜在应用。
