CuFe2O4/硅藻土复合材料活化过一硫酸盐降解酸性橙7

CuFe2O4/diatomite composite activated persulfate to degrade acid orange 7

摘要:

通过柠檬酸辅助溶胶凝胶法制备了一种磁性复合材料CuFe2O4/硅藻土（CFD）。通过SEM、XRD、FTIR、XPS表征分析了材料的微观形貌结构和元素价态，并探讨了不同氧化体系、CFD质量浓度、PMS质量浓度、溶液初始pH、反应温度、阴离子种类等对CFD体系降解酸性橙7（AO7）的影响。结果表明，CFD上的球状颗粒CuFe2O4能够分散地负载在硅藻土上，减少了纯CuFe2O4的团聚，且CFD复合材料上的表面羟基及Fe3+/Fe2+、Cu2+/Cu+之间的价态循环参与了PMS的活化。在CFD质量浓度为0.5 g/L、PMS质量浓度为0.3 g/L，AO7质量浓度为50 mg/L，反应温度为30 ℃的最佳条件下，60 min时的AO7降解率为96.88%，CFD+PMS体系降解AO7过程符合准一级动力学模型，且相比于纯CuFe2O4+PMS体系，对AO7的降解速率常数提升了1.98倍。单因素影响试验结果表明，CFD+PMS体系的pH适用范围广（5~11），具有较低的活化能（Ea=31.77 kJ/mol）。猝灭试验表明，降解过程的主要活性物质为1O2和?O2-，同时也有SO4-?、?OH产生。

Abstract:

A magnetic composite CuFe2O4/diatomite (CFD) was prepared by citric acid assisted sol-gel method. The microstructure and elemental valence of the materials were analyzed by SEM, XRD, FTIR and XPS, and the effects of different oxidation systems, mass concentration of CFD, mass concentration of PMS, initial pH of solution, reaction temperature and anion type on the degradation of AO7 by CFD system were discussed. The results show that the spherical CuFe2O4 particles on CFD can be dispersed on diatomite, which reduces the agglomeration of pure CuFe2O4, and the valence cycles among the surface hydroxyl group, Fe3+/Fe2+ and Cu2+/Cu+ on CFD composite are involved in the activation of PMS. Under the optimal conditions of 0.5 g/L mass concentration of CFD, 0.3 g/L mass concentration of PMS, 50 mg/L mass concentration of AO7 and 30 ℃ reaction temperature, the degradation rate of AO7 in 60 min was 96.88%. The degradation process of AO7 in CFD+PMS system was in line with the quasi-first-order kinetic model. Compared with pure CuFe2O4+PMS system, the degradation rate constant of AO7 is increased by 1.98 times. The single factor test results show that the pH range of CFD+PMS system is wide (5~11) and the activation energy is low (Ea=31.77 kJ/mol). The quenching test showed that the main active substances in the degradation process were 1O2 and ?O2-, and SO4-? and ?OH were also produced.