Sorption of perfluorooctane sulfonate and perfluorooctanoate on polyacrylonitrile fiber-derived activated carbon fibers: in comparison with activated carbon

Abstract

Polyacrylonitrile fiber (PANF)-derived activated carbon fibers (PACFs) were successfully prepared using a one step carbonation-activation, and were used for the sorption of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA). High specific surface areas (SSAs) of 1782 m 2 g À1 and micro/ mesoporous structures of the PACFs were obtained by optimizing the preparation conditions of the PANF-based pre-oxidized fibers (PANOFs)/KOH ratio of 1 : 2 and an activation temperature of 800 C.The as-prepared PACFs exhibited flexibility and endless forms, and sorption capacities of 1.52 mmol g À1for PFOS and 0.73 mmol g À1 for PFOA, much higher than the commercially available coal-based powder activated carbon (PAC) and granular activated carbon (GAC), which was also indicated by the site energy distributions. The sorption system followed a pseudo-second-order kinetic model and a Freundlich isotherm model. The intra-particle diffusion and Boy's film-diffusion models were also used to verify that intra-particle diffusion is the main rate-controlling step. It was assumed that the multilayer sorption most probably occurs through electrostatic attraction and hydrophobic interaction, and some micelles and hemi-micelles form on the ACF surfaces. The PACFs show good reusability over five sorptiondesorption cycle studies.

Adsorption for perfluorooctanoic acid with graphitic‐phase carbon nitride and its HPLC fluorescence determination

“…In addition, when considering the hydrophobic property of the C‐F chain in PFOA and the electrostatic repulsion between the adsorbed PFOA, there is a tendency for hemi‐micelle formation on the interface of the g‐C 3 N 4 . The considerable adsorption capacity of PFOA onto g‐C 3 N 4 when compared to previous reports can be attributed to the reasons mentioned above …”

Polymer Supported Carbon for Safe and Effective Remediation of PFAS-Contaminated Water

“…Additionally, the carbon-polymer blend is easier to remove from water by filtration than the PAC alone (vide infra), overcoming this common problem with PAC. 33 The dust generation was quantified using a nephelometer (Figure 4 and S10). In the event, a 100 mL dry volume of the PAC or the carbon-polysulfide blend was poured in one portion from a 20 cm height into a cylindrical plastic container (12 cm diameter × 10 cm height).…”

Selectivity of Per- and Polyfluoroalkyl Substance Sensors and Sorbents in Water

“…Carbonaceous sorbents include GAC, 73 powdered activated carbon (PAC), 74 biochar, 75 single-walled carbon nanotubes (SWNTs), 76 multiwalled carbon nanotubes (MWNTs), 77 carbon fiber, 78 and carbon microspheres (CMSs). 79 GAC and PAC, as the commercially available sorbents, are economic, scalable, and eco-friendly, but their application has been limited by the insufficient selectivity and slow adsorption kinetics.…”

“…For example, Chen et al fabricated polyacrylonitrile fiber (PANF)-derived activated carbon fibers (PACFs) and achieved an adsorption capacity for a PFOA of 302.3 mg/g and PFOS of 760.2 mg/g, which is 1.5 to 2.5 times higher than those of PAC and GAC ( Figure 4 a,b). 78 In order to increase the selectivity and improve the adsorption performance of carbonaceous sorbents, a series of material engineering methods have been explored. Common sorbent modification strategies include introducing surface functional groups by oxidation, 81 mixing with polymeric substrate, 82 loading with metal oxide nanoparticles, 77 and coating with MIPs.…”