GenX is Not Always a Better Fluorinated Organic Compound Than PFOA: A Critical Review on Aqueous Phase Treatability by Adsorption and Its Associated Cost

Authors

Hamed Heidari, University of Nevada, Las Vegas
Tauqeer Abbas, University of Nevada, Las Vegas
Yong Sik Ok, Korea University
Daniel C.W. Tsang, Hong Kong Polytechnic University
Amit Bhatnagar, LUT University
Eakalak Khan, University of Nevada, Las VegasFollow

Document Type

Article

Publication Date

9-23-2021

Publication Title

Water Research

Volume

205

First page number:

1

Last page number:

17

Abstract

Hexafluoropropylene oxide dimer acid (GenX) has been marketed as a substitute for perfluorooctanoic acid (PFOA) to reduce environmental and health risks. GenX and PFOA have been detected in various natural water sources, and adsorption is recognized as a typical treatment process for PFOA removal. In this paper, comparisons of GenX and PFOA adsorption are evaluated, including adsorption potential, adsorption mechanisms, and associated costs. A detailed literature review suggests that anion-exchange resins are more effective in removing GenX than activated carbon. GenX removal efficiency through activated carbon (30%) is lower than that of PFOA (80–95%), while GenX and PFOA removal efficiencies by anion exchange resins are similar (99%). Unconventional adsorbents, such as ionic fluorogels and covalent organic frameworks can effectively remove GenX from water. The review reveals that GenX adsorption is more challenging, requiring almost 4 times the treatment cost of its predecessor, PFOA. Annual operation and maintenance costs for GenX adsorption (initial concentration of GenX and PFOA = 0.2 µg.L−1) by GAC for treating 10,000 m3 per day is almost US$1,000,000 per year, but only around US$240,000 per year for PFOA. Desorption of GenX in the presence of PFOA highlights GenX's inferior treatability by adsorption. It is believed that GenX is a more environmentally friendly compound than PFOA, but this environmental friendliness comes with the price.

Keywords

Activated carbon; Drinking water; Emerging contaminants; Remediation technologies; Water treatment

Disciplines

Civil and Environmental Engineering

Language

English

Repository Citation

Heidari, H., Abbas, T., Ok, Y., Tsang, D. C., Bhatnagar, A., Khan, E. (2021). GenX is Not Always a Better Fluorinated Organic Compound Than PFOA: A Critical Review on Aqueous Phase Treatability by Adsorption and Its Associated Cost. Water Research, 205 1-17.
http://dx.doi.org/10.1016/j.watres.2021.117683