Energy Evaluation of Electron Beam Treatment of Perfluoroalkyl Substances in Water: A Critical Review

Abstract

Due to their recalcitrant nature and ubiquitous use, per-and polyfluoroalkyl substances (PFAS) will continue to be major water treatment hurdles. Although effective water treatment technologies exist for physical removal of many PFAS from water (e.g., activated carbon and ion-exchange resin), a PFAS-concentrated waste stream is generated as an end product that can potentially reintroduce PFAS back into the environment. Thus, there is an increased interest in developing destructive technologies to decompose and mineralize PFAS directly in water or in these waste streams. High energy electron beam (e-beam) accelerators have been used for water treatment to degrade a wide range of recalcitrant contaminants, including PFAS, since the 1960s. However, large-scale applications of e-beam for water treatment are restricted due to its high energy consumption and inability to treat large flow rates. Considering there are very few available technologies for destructive removal of PFAS, this study provides a critical review on the treatment of PFAS by direct irradiation of contaminated water by e-beam from an energy consumption point of view. To date, very limited studies have been conducted to investigate the success of this technology to treat PFAS. Results from the limited studies were not directly comparable due to the variation in operating conditions and water quality parameters used in the studies. Here, for the first time, we develop and apply the concept of electrical energy per order (EE/O) to assess the performance of e-beam for PFAS treatment. Results show that EE/O is a better performance parameter than the G value of e-beam for interstudy comparisons and to evaluate the effects of water quality and operating parameters on e-beam performance. We additionally developed a kinetic scheme to predict the performance of e-beam to treat PFAS and revealed that the competition between species to react with aqueous electrons is the determinant factor influencing PFAS degradation efficiency. Comparison of EE/O values of e-beam (range: 31−176 kWh m −3 order −1 ) with other destructive technologies (range: 5−9595 kWh m −3 order −1 ) suggest that e-beam, for PFAS treatment, is a promising approach under favorable conditions. This review further elucidates the feasibility and limitations of e-beam technology that could be improved upon to potentially make e-beam viable for large-scale water treatment applications.

Functionalized bio‐adsorbents for removal of perfluoroalkyl substances: A perspective

“…These techniques include electrochemical oxidation (Chaplin, 2020;Nzeribe et al, 2019), plasma (Hayashi et al, 2015;Nzeribe et al, 2019;Singh et al, 2019), electron beam (Londhe et al, 2021), and activated persulfate (Nzeribe et al, 2019), all exhibiting promising potential to degrade long-chain PFAS, such as PFOA and PFOS. When the degradation of short-chain PFAS has been studied, the degradation efficiencies were poor, compared to their long-chain counterparts (Barisci & Suri, 2020, 2021Lewis et al, 2020;Londhe et al, 2021;Nzeribe et al, 2019;Wang, Nickelsen, et al, 2020). However, these techniques are generally energy-intensive and not cost-effective except for the remediation of some heavily contaminated solutions.…”

A Review on Removal and Destruction of Per- and Polyfluoroalkyl Substances (PFAS) by Novel Membranes

“…mdpi.com/article/10.3390/membranes12070662/s1, Table S1: Recently reported adsorption techniques to remove PFAS from wastewater, Table S2: Recently reported studies on ion exchange resins for PFAS removal, SI 1: Destruction techniques. References [23,46,48,53,56,58,66,128,132,135,[141][142][143][144][145][146][147]…”

“…Physical separation techniques (e.g., adsorption, ion-exchange resins, membrane separation, e.g., NF or RO) are able to remove PFAS from the liquid phase onto adsorbent materials or into a concentrated brine solution. As these processes are unable to destroy PFAS, which are considered ‘forever chemicals’ [ 63 , 127 , 128 ] resulting from the strong C–F bond, there is a need to deal with the disposal of absorbents contaminated with PFAS or PFAS-concentrated-brine which may raise secondary pollution risks.…”

“…The following supporting information can be downloaded at: , Table S1: Recently reported adsorption techniques to remove PFAS from wastewater, Table S2: Recently reported studies on ion exchange resins for PFAS removal, SI 1: Destruction techniques. References [ 23 , 46 , 48 , 53 , 56 , 58 , 66 , 128 , 132 , 135 , 141 , 142 , 143 , 144 , 145 , 146 , 147 , 153 , 154 , 155 , 156 , 157 , 158 , 159 , 160 , 161 , 162 , 163 , 164 , 165 , 166 , 167 , 168 , 169 , 170 , 171 , 172 , 173 , 174 , 175 , 176 , 177 , 178 , 179 , 180 , 181 , 182 , 183 , 184 , 1...…”

Efficient removal of short-chain and long-chain PFAS by cationic nanocellulose

“…9 Among the many remediation methods demonstrated, adsorption is the simplest and most cost-effective approach to remove PFASs. This is because other remediation methods, such as electrochemical oxidation or electron beam, capable of destroying/degrading the PFAS components, 10 require complex instrumental setup and intensive energy consumption. 11 The incomplete destruction process by these methods can also produce short-chain PFASs that remain harmful.…”