Visible-light-excited humic acid for peroxymonosulfate activation to degrade bisphenol A
Visible-light-excited humic acid for peroxymonosulfate activation to degrade bisphenol A
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DOI：
10.1016/j.cej.2020.125853
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发表时间：
2020-11-15
影响因子：
15.1
通讯作者：
Wang, Xin
中科院分区：
文献类型：
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作者：
Jia, Jialin;Liu, Dongmei;Wang, Xin
本研究建立了一种可见光（VL）激发腐植酸（HA）活化过氧单硫酸盐（PMS）的新方法，并将其应用于双酚a （BPA）的降解。结果表明，在HA (2 mg/L)/PMS (1 mM)/VL体系中，30 min内BPA的降解率可达95.4%，远高于HA/VL体系（9.4%）和PMS/VL体系（15.5%）。同时，在此过程中，HA的浓度也下降，HA原有的结构被明显破坏。通过猝灭实验、电子顺磁共振（EPR）检测和HA分选实验，阐明了HA在PMS/HA/VL体系中对BPA降解影响的反应机理。结果表明，单重态氧（O-1(2)）、羟基自由基（中心点OH）和硫酸根自由基（中心点- SO4）均参与了该体系的降解，其中(1)O(2)是参与BPA降解的主要活性物质。HA的芳香族成分对反应物质的生成贡献最大，其中酚基作为电子给体，醌基作为电子穿梭体，加速HA与PMS之间的电子传递，从而激活PMS形成降解BPA的反应物质。由于HA在自然界中普遍存在，本研究可能为PMS辅助原位水处理提供新的思路。
In this study, a novel peroxymonosulfate (PMS) activation method by visible light (VL) excited humic acid (HA) was developed and applied to degradation of bisphenol A (BPA). Results showed that, in HA (2 mg/L)/PMS (1 mM)/VL system, the degradation rate of BPA could reach 95.4% within 30 min, which was much higher than that of HA/VL system (9.4%) and PMS/VL system (15.5%). Meanwhile, the concentration of HA was also decreased in this process and the original structure of HA was obviously destroyed. Reaction mechanism accounting for the effect of HA on BPA degradation in the PMS/HA/VL system was explicated by the quenching experiments, electron paramagnetic resonance (EPR) detection and HA fractionation experiments. Results showed that singlet oxygen (O-1(2)), hydroxyl radical (center dot OH) and sulfate radical (SO4 center dot-) were all involved in the system, and( 1)O(2) was the primary reactive species responsible for BPA degradation. The aromatic constituents of HA made the dominant contribution to the generation of reactive species, in which the phenolic groups played the role of electron-donor, and the quinone moieties acted as the electron shuttles could accelerate the electron-transfer between HA and PMS, which thus activated PMS to form the reactive species for BPA degradation. As HA is ubiquitous in nature, this study may provide a new insight into the in situ water treatment with the assistance of PMS.