Dynamic monitoring and regulation of pentachlorophenol photodegradation process by chemiluminescence and TiO2/PDA

Fengjie Chen; Lixia Zhao; Wanchao Yu; Yarui Wang; Hui Zhang; Liang-Hong Guo

doi:10.1016/j.jhazmat.2020.123073

Dynamic monitoring and regulation of pentachlorophenol photodegradation process by chemiluminescence and TiO₂/PDA

J Hazard Mater. 2020 Nov 15:399:123073. doi: 10.1016/j.jhazmat.2020.123073. Epub 2020 May 31.

Authors

Fengjie Chen¹, Lixia Zhao², Wanchao Yu¹, Yarui Wang¹, Hui Zhang³, Liang-Hong Guo¹

Affiliations

¹ State Key Laboratory of Environmental Chemistry and Eco-toxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, P.O. Box 2871, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100039, China.
² State Key Laboratory of Environmental Chemistry and Eco-toxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, P.O. Box 2871, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100039, China. Electronic address: zlx@rcees.ac.cn.
³ State Key Laboratory of Environmental Chemistry and Eco-toxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, P.O. Box 2871, Beijing 100085, China.

PMID: 32534397
DOI: 10.1016/j.jhazmat.2020.123073

Abstract

Pentachlorophenol (PCP), a highly toxic halogenated aromatic compound, and its direct photolysis or TiO₂ photocatalysis may generate toxic intermediates and induce secondary pollution in the environment. It is urgently needed to design a strategy to inhibit the toxic intermediates in the photodegradation of PCP. To achieve this, polydopamine (PDA), a non-toxic substance, modified TiO₂ (P25/PDA) nanoparticles were synthesized and used to improve the PCP photodegradation process. The dynamic tracking of toxic intermediates tetrachloro-1,4-benzoquinone (TCBQ) and trichlorohydroxy-1,4-benzoquinone (OH-TrCBQ) produced in the PCP photodegradation process were obtained by continuous flow chemiluminescence. Combined with reactive oxygen species (ROS) measurements, P25/PDA could approximatively depress 70 % TCBQ and 40 % OH-TrCBQ generation through the regulation of ROS especially the generation of a fairly large amount of H₂O₂ (about 30 μM) and O₂^- (about 20 μM) on the surface of the P25/PDA. The toxicity evaluation showed that the photodegradation of PCP by P25/PDA was a safer and green approach. Therefore, it was instructive to inhibit the formation of highly toxic intermediates in the photodegradation of environmental contaminants by regulating the ROS generated on the surface of the photocatalysts.

Keywords: Chemiluminescence; PCP photodegradation process; PDA modified TiO(2); TCBQ and OH-TrCBQ; Toxic intermediates.

Publication types

Research Support, Non-U.S. Gov't