ABTS as an electron shuttle to accelerate the degradation of diclofenac with horseradish peroxidase-catalyzed hydrogen peroxide oxidation.

Horseradish peroxidase (HRP)-catalyzed hydrogen peroxide (H2O2) oxidation could degrade a variety of organic pollutants, but the intrinsic drawback of slow degradation rate limited its widespread application. In this study, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) was introduced into HRP/H2O2 system as an electron shuttle to enhance diclofenac degradation under neutral pH conditions. The green-colored ABTS radical (ABTS•+), generated by the oxidation of ABTS with HRP-catalyzed H2O2 oxidation, was proved to be the main reactive species for the rapid degradation of diclofenac in HRP/H2O2/ABTS system. There was no destruction of ABTS/ABTS•+ in HRP/H2O2/ABTS system, and ABTS was verified as an ideal electron shuttle. The reaction conditions including solution pH (4.5-10.5), HRP concentration (0-8 units mL-1) and H2O2 concentration (0-500 μM) would impact the formation of ABTS•+, and affect the degradation of diclofenac in HRP/H2O2/ABTS system. Moreover, compared with Fenton and hydroxylamine/Fenton systems, HRP/H2O2/ABTS system had better diclofenac degradation efficiency, higher H2O2 utilization efficiency and stronger anti-interference capacity in actual waters. Overall, the present study provided a meaningful and promising way to enhance the degradation of organic pollutants in water with HRP-catalyzed H2O2 oxidation. Copyright © 2021 Elsevier B.V. All rights reserved.

Citation

Yixin Huang, Jinbin Lin, Jing Zou, Jiaxin Xu, Mengyun Wang, Huahua Cai, Baoling Yuan, Jun Ma. ABTS as an electron shuttle to accelerate the degradation of diclofenac with horseradish peroxidase-catalyzed hydrogen peroxide oxidation. The Science of the total environment. 2021 Dec 01;798:149276

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PMID: 34333427

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