Abstract：
The bicarbonate-activated hydrogen peroxide (BAP) system is widely studied for organic pollutant degradation in wastewater treatment. Ca2Co2O5, a heterogeneous catalyst containing multivalent cobalt including Co(II) and Co(III), was herein investigated as a BAP activator, and Acid Orange 7 (AO7) was used as a model pollutant. Ca2Co2O5 exhibited good activation performance. The degradation rate and the initial rate constant of the Ca2Co2O5-activated BAP system were 5.4 and 11.2 times as high as the BAP system, respectively. The removal rate of AO7 reached 90.9% in 30 min under optimal conditions (AO7 20 mg/L, Ca2Co2O5 0.2 g/L, H2O2 1 mM, NaHCO3 5 mM, pH 8.5, 25℃). The Ca2Co2O5 catalyst exhibited good stability and recyclability, retaining 85% of AO7 removal rate in the fifth run. Compared to the BAP system, a lower dosage of H2O2 was required and a higher initial concentration of pollutants allowed for effective degradation in the Ca2Co2O5-BAP system. X-ray photoelectron spectroscopy was used to analyze the catalytic mechanism. The analysis showed that the good catalytic performance of Ca2Co2O5 attributes to its high proportion of oxygen vacancies and Co(III) species, and the presence of Ca. The active species O2•-, •OH, and 1O2 are responsible for the degradation, as indicated by the quenching experiments. The degradation mechanism of AO7 was speculated based on UV-Vis spectral analysis and the identification of degradation intermediates. The azo form, naphthalene and benzoic rings in the AO7 structure are destroyed in the decomposition. This research provides a feasible approach to designing effective and reusable BAP activators for pollutant degradation in wastewater treatment.
摘要：
碳酸氢盐活化过氧化氢（BAP）体系在废水处理中被广泛研究用于有机污染物的降解。Ca2Co2O5，一种含有多价钴的多相催化剂，包括Co（II）和Co（III），本文作为BAP激活剂进行了研究，酸性橙7（AO7）用作模型污染物。Ca2Co2O5表现出良好的活化性能。Ca2Co2O5活化的BAP体系的降解速率和初始速率常数分别是BAP体系的5.4倍和11.2倍，分别。在最佳条件下，30min内AO7的去除率达到90.9%(AO720mg/L,Ca2Co2O50.2g/L，H2O21mM，NaHCO35mM,pH8.5,25℃)。Ca2Co2O5催化剂具有良好的稳定性和可回收性,在第五次运行中保留了85%的AO7去除率。与BAP系统相比，在Ca2Co2O5-BAP系统中，需要较低的H2O2剂量和较高的污染物初始浓度才能有效降解。利用X射线光电子能谱对催化机理进行了分析。分析表明，Ca2Co2O5的良好催化性能归因于其高比例的氧空位和Co（III）物种，还有Ca的存在.活性物种O2•-，•OH,和1O2负责降解，如淬火实验所示。基于紫外-可见光谱分析和降解中间体的鉴定，推测了AO7的降解机理。偶氮形式，AO7构造中的萘和苯甲酸环在分解中遭到破坏。该研究为设计有效且可重复使用的BAP活化剂用于废水处理中的污染物降解提供了可行的方法。
