Selective sequestration of perfluorinated compounds using polyaniline decorated activated biochar

Enhanced Removal of Polyfluoroalkyl Substances by Simple Modified Biochar: Adsorption Performance and Theoretical Calculation

“…This also explained the experimental phenomenon that the adsorption capacity of H-SL biochar for PFOS was better than that for PFOA, and this was consistent with the existing research results. , Based on the DFT calculation results, it can be confirmed that functional groups are also important factors in the adsorption process. Moreover, hydrogen bonding between anionic species of PFAS and functional groups was also a possible mechanism, owing to the deprotonation of PFAS. , According to the spectra of N 1s (Figure S3), the pyrrolic N contained in H-SL biochar increased from 49.5 to 57.8% compared with that in SL biochar, while the content of pyridinic N and graphite N decreased. Pyrrolic N will form when N atoms in biochar bind to heterocyclic rings, which can form weak hydrogen bonds with compounds .…”

“…Moreover, hydrogen bonding between anionic species of PFAS and functional groups was also a possible mechanism, owing to the deprotonation of PFAS. 19,39 According to the spectra of N 1s (Figure S3), the pyrrolic N contained in H-SL biochar increased from 49.5 to 57.8% compared with that in SL biochar, while the content of pyridinic N and graphite N decreased. Pyrrolic N will form when N atoms in biochar bind to heterocyclic rings, which can form weak hydrogen bonds with compounds.…”

“…Therefore, the contribution of interaction in the PFAS adsorption process is different under different pH conditions. 19,20 It is difficult to select a high-quality adsorbent from different biomass raw materials owing to the differences in experimental design among different researchers. In addition, the biochar obtained by pyrolysis of the same raw material has similar physical and chemical properties, which makes it difficult to explore the effect of the difference in the physical and chemical properties of biochar on PFAS adsorption.…”

“…In addition, the adsorption capacity of biochar for PFAS is satisfactory. , It is noteworthy that many studies on PFAS adsorption have been based on modified biochar prepared from a single raw material. For example, Yea et al found that the adsorption capacity of polyaniline-decorated activated biochar for PFOS and PFOA was 349.5 and 264.6 mg·g –1 , respectively. Wu et al engineered the biochar derived from water oak leaves with additives of FeCl 3 , increasing the PFOA adsorption capacity from 23.4 to 42.2 mg·g –1 .…”

“…In addition, the surface of biochar has abundant functional groups as hydrogen donors that can bind to PFAS by hydrogen bonding under acidic media. Therefore, the contribution of interaction in the PFAS adsorption process is different under different pH conditions. , …”