Efficient adsorptive removal of short-chain perfluoroalkyl acids using reed straw-derived biochar (RESCA)
Document Type
Article
Publication Date
12-1-2021
Abstract
Drinking water and groundwater treatment of perfluoroalkyl acids (PFAAs) heavily relies on adsorption-based approaches using carbonaceous materials, such as granular activated carbon (GAC). Application of GAC is restricted by its inefficiency to remove short-chain PFAAs that have prevalently emerged as substitutes and/or metabolites of long-chain polyfluoroalkyl and perfluoroalkyl substances (PFAS). Here, we synthesized reed straw-derived biochar (RESCA) exhibiting exceptional removal efficiencies (>92%) toward short-chain PFAAs at environment-relevant concentrations (e.g., 1 μg/L). Pseudo-second-order kinetic constants of RESCA were 1.13 and 1.23 L/(mg h) for perfluorobutanoic acid (PFBA) and perfluorobutanesulfonic acid (PFBS), respectively, over six times greater than GAC. SEM imaging and BET analysis revealed the combination of highly hydrophobic surface and scattered distribution of mesopores (2–10 nm in diameter) was associated with the rapid adsorption of short-chain PFAAs. RESCA-packed filters demonstrated effective removal of the mixture of three short-chain and three long-chain PFAAs in the influent with the flow rate up to 45 mL/min. In contrast, GAC-packed filters were significantly less efficient in the removal of short-chain PFAAs, which were also negatively affected by the increase of the flow rate. Efficacy of RESCA-packed filters was also validated in four PFAA-spiked groundwater samples from different sites. Dissolved organic matter (DOC) of >8 mg/L can negatively affect the removal of short-chain PFAAs by RESCA. Feasibility of scaling up the RESCA adsorption system was investigated using breakthrough simulation. Overall, RESCA represents a green adsorbent alternative for the feasible and scalable treatment of a wide spectrum of PFAAs of different chain lengths and functional moieties.
Identifier
85111267117 (Scopus)
Publication Title
Science of the Total Environment
External Full Text Location
https://doi.org/10.1016/j.scitotenv.2021.149191
e-ISSN
18791026
ISSN
00489697
PubMed ID
34333431
Volume
798
Grant
CBET-1903597
Fund Ref
National Science Foundation
Recommended Citation
Liu, Na; Wu, Chen; Lyu, Guifen; and Li, Mengyan, "Efficient adsorptive removal of short-chain perfluoroalkyl acids using reed straw-derived biochar (RESCA)" (2021). Faculty Publications. 3625.
https://digitalcommons.njit.edu/fac_pubs/3625
