PFAS treatment with granular activated carbon and ion exchange resin: Comparing chain length, empty bed contact time, and cost

Pilot‐scale comparison of granular activated carbons, ion exchange, and alternative adsorbents for per‐ and polyfluoroalkyl substances removal

“…In addition to differences between PFOS and PFOA adsorption, the results from the present study also showed that there is a strong correlation between the carbon chain length and adsorbability, specifically for PFSAs, regardless of carbon type, for example, bituminous, sub‐bituminous, or non‐bituminous. It was observed that all GACs evaluated in the present study had a higher removal efficiency or adsorbability for long‐chained PFSAs as compared with short‐chained PFSAs (see Figure 5a), which agrees with results from previous studies (Belkouteb et al, 2020; Liu et al, 2019; McLeaf et al, 2017; Murray et al, 2021; Rahman et al, 2014). A similar observation could not be made for PFCAs due to the low or non‐detect concentrations of PFCAs in the influent water in this study; however, others have found that chain length for PFCAs determined the removal efficiency (McLeaf et al, 2017; Rodowa et al, 2020).…”

“…Figure 7 plots the total effluent PFAS concentrations for IX and AAs at specific time intervals. Comparing performance for different PFAS, Figure 7 shows that in general IX resins were least effective at removing PFOA (magenta bars) and PFBS (blue bars) and were most effective at removing long‐chain PFSAs (in this case PFOS and PFHxS), consistent with other studies (Belkouteb et al, 2020; Liu et al, 2019; McLeaf et al, 2017; Murray et al, 2021; Rahman et al, 2014). PFHxA was only sporadically detected over time, with effluent concentrations ranging between non‐detect to 4.9 ng/L; in contrast the maximum recorded concentration was 2.5 ng/L for GAC effluents (only slightly above the reporting limit).…”

“…GACs are more effective at removing long‐chained compounds than short‐chained compounds, therefore, faster breakthrough of short‐chained PFBS was expected (Murray et al, 2021; Rahman et al, 2014). There are only slight differences in the removal of PFBS between bituminous and non‐/sub‐bituminous carbons.…”

“…These differences may be due to the differences in the sizes and distribution of micropores and mesopores within the GACs (Liu et al, 2019). Liu et al, 2019;McLeaf et al, 2017;Murray et al, 2021;Rahman et al, 2014). PFHxA was only sporadically detected over time, with effluent concentrations ranging between non-detect to 4.9 ng/L; in contrast the maximum recorded concentration was 2.5 ng/L for GAC effluents (only slightly above the reporting limit).…”

Occurrence of per- and polyfluoroalkyl substances in water: a review

“…113,133,134 As for spent AEX, there have been promising reports on coupling AEX with electrochemical oxidation to destruct PFASs in the concentrated wastes resulting from AEX regeneration. 135,136 It appears that AEX tends to be more cost effective than GAC for PFAS treatment, 137,138 and it is dependent on the treatment target. 139 Some studies focused on furthering the selectivity of these adsorbent materials through engineering.…”