Highly efficient and stable Zr-doped nanocrystalline PbO2 electrode for mineralization of perfluorooctanoic acid in a sequential treatment system

Zesheng Xu; Yanxin Yu; Han Liu; Junfeng Niu

doi:10.1016/j.scitotenv.2016.11.180

Highly efficient and stable Zr-doped nanocrystalline PbO₂ electrode for mineralization of perfluorooctanoic acid in a sequential treatment system

Sci Total Environ. 2017 Feb 1:579:1600-1607. doi: 10.1016/j.scitotenv.2016.11.180. Epub 2016 Dec 5.

Authors

Zesheng Xu¹, Yanxin Yu¹, Han Liu¹, Junfeng Niu²

Affiliations

¹ State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
² State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China; School of Environment and Civil Engineering, Dongguan University of Technology, Dongguan 523808, PR China. Electronic address: junfengn@bnu.edu.cn.

PMID: 27932217
DOI: 10.1016/j.scitotenv.2016.11.180

Abstract

Zr-doped nanocrystalline PbO₂ (Zr-PbO₂) film electrodes were prepared at different bath temperatures. The Zr-PbO₂ electrode doped at 75°C (75-Zr-PbO₂) featured high oxygen evolution overpotential, large effective area and good electrocatalytic performance. The oxygen evolution potential and the effective area of 75-Zr-PbO₂ achieved 1.91V (vs. SCE) and 9.1cm², respectively. The removal efficiency and the defluorination ratio of PFOA reached 97.0% and 88.1% after 90min electrolysis. The primary mineralization products (i.e., F^- and intermediates) and their change trends were determined. The 75-Zr-PbO₂ electrode was introduced to sequentially treat the PFOA wastewater. In an 116h of 75-Zr-PbO₂ electrocatalysis sequential process, the PFOA, PFHpA, PFHxA, PFPeA, PFBA, PFPrA, TFA, and TOC concentrations were reduced to below 30, 2.5, 1.3, 1.0, 0.5, 0.2, 0.1, and 9mgL^-1, respectively, demonstrating the promising application of the sequential treatment system for the treatment of PFOA wastewater.

Keywords: Continuous-flow reactor; Defluorination; Electrochemical degradation; Mechanisms; Perfluorooctanoic acid.