Affiliations 

  • 1 Department of Chemistry, College of Natural and Applied Science, Al-Qalam University Katsina, 2137, Katsina, Nigeria; Institute of Semi-Arid Zone Studies, Al-Qalam University Katsina, 2137, Katsina, Nigeria. Electronic address: zakariyyazango@auk.edu.ng
  • 2 Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan, Taiwan
  • 3 Department of Chemistry, College of Natural and Applied Science, Al-Qalam University Katsina, 2137, Katsina, Nigeria
  • 4 Department of Quality Assurance and Control, Dangote Cement Plc, Kogi, Nigeria
  • 5 Institute of Semi-Arid Zone Studies, Al-Qalam University Katsina, 2137, Katsina, Nigeria
  • 6 Department of Civil Engineering, Kano University of Science and Technology, Wudil, P.M.B. 3244, Kano, Nigeria
  • 7 School of Chemical Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia
  • 8 HICoE-Centre for Biofuel and Biochemical Research, Institute of Self-Sustainable Building, Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, 32610, Seri Iskandar, Perak Darul Ridzuan, Malaysia
Environ Res, 2023 Mar 15;221:115326.
PMID: 36690243 DOI: 10.1016/j.envres.2023.115326

Abstract

Perfluorooctanoic acid (PFOA) has been identified as the most toxic specie of the family of perfluorinated carboxylic acids (PFCAs). It has been widely distributed and frequently detected in environmental wastewater. The compound's unique features such as inherent stability, rigidity, and resistance to harsh chemical and thermal conditions, due to its multiple and strong C-F bonds have resulted in its resistance to conventional wastewater remediations. Photolysis and bioremediation methods have been proven to be inefficient in their elimination, hence this article presents intensive literature studies and summarized findings reported on the application of advanced oxidation processes (AOPs) and photocatalytic degradation techniques as the best alternatives for the PFOA elimination from wastewater. Techniques of persulfate, photo-Fenton, electrochemical, photoelectrochemical and photocatalytic degradation have been explored and their mechanisms for the degradation and defluorination of the PFOA have been demonstrated. The major advantage of AOPs techniques has been centralized on the generation of active radicals such as sulfate (SO4•-) hydroxyl (•OH). While for the photocatalytic process, photogenerated species (electron (e) and holes (h + vb)) initiated the process. These active radicals and photogenerated species possessed potentiality to attack the PFOA molecule and caused the cleavage of the C-C and C-F bonds, resulting in its efficient degradation. Shorter-chain PFCAs have been identified as the major intermediates detected and the final stage entails its complete mineralization to carbon dioxide (CO2) and fluoride ion (F-). The prospects and challenges associated with the outlined techniques have been highlighted for better understanding of the subject matter for the PFOA elimination from real wastewaters.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.