Can porous carbons be a remedy for PFAS pollution in water? A perspective

Saha, Dipendu; Khan, Sandip; Bramer, Scott E. Van

doi:10.1016/j.jece.2021.106665

Cited by 19 publications

(22 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Currenlty, featuring larger overall hydrophobic surface areas, novel strategies including powdered activated carbon (PAC), nanoporous carbon, enhanced biochars, and cellulose are developed pursuing higher efficiency and capacity than GAC. ,,,− However, the efficiency of activated carbon base strategies is commonly compromised in the presence of other soluble co-contaminants . Sorption of those nonfluorinated impurities can result in the sorbent reaching capacity prior to the capture of PFAS.…”

Section: Interaction Mechanisms With Pfasmentioning

confidence: 99%

“…27,28 The micropore surface area on GAC was found to be essential in the hydrophobic interaction with PFAS, and preference of pore sizes has also been found to be associated with PFAS chain lengths. 29,30 Mesopores (0.002−0.05 μm) are found to be favored over micropores (<0.002 μm) in the adsorption of long-chain PFAS such as PFOS and PFOA, whereas contradictory findings are associated with the adsorption of shortchain PFASs. 26,31 Currenlty, featuring larger overall hydrophobic surface areas, novel strategies including powdered activated carbon (PAC), nanoporous carbon, enhanced biochars, and cellulose are developed pursuing higher efficiency and capacity than GAC.…”

Section: ■ Interaction Mechanisms With Pfas Hydrophobic Interaction W...mentioning

confidence: 99%

See 1 more Smart Citation

Advancing PFAS Sorbent Design: Mechanisms, Challenges, and Perspectives

He,

Cheng,

Gunjal

et al. 2023

ACS Mater. Au

View full text Add to dashboard Cite

Per-and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals characterized with persistence and multisurface resistance. Their accumulation in the environment and toxicity to human beings have contributed to the rapid development of regulations worldwide since 2002. The sorption strategy, taking advantage of intermolecular interactions for PFAS capture, provides a promising and efficient solution to the treatment of PFAS contaminated sources. Hydrophobic and electrostatic interactions are the two commonly found in commercially available PFAS sorbents, with the fluorous interaction being the novel mechanism applied for sorbent selectivity. The main object of this Perspective is to provide a critical review on the current design criteria of PFAS sorbents, with particular focus on their sorption and interaction mechanisms as well as limitations. An outlook on future innovative design for efficient PFAS sorbents is also provided.

show abstract

Section: Interaction Mechanisms With Pfasmentioning

confidence: 99%

Section: ■ Interaction Mechanisms With Pfas Hydrophobic Interaction W...mentioning

confidence: 99%

Advancing PFAS Sorbent Design: Mechanisms, Challenges, and Perspectives

He,

Cheng,

Gunjal

et al. 2023

ACS Mater. Au

View full text Add to dashboard Cite

show abstract

“…GAC, for instance, is well-known for its slow adsorption kinetics and comparatively lower efficiency in removing short-chain PFAS and precursors in comparison to long-chain counterparts. 20,21 On the other hand, superfine PAC facilitates the rapid diffusion of short-chain PFAS molecules for swift adsorption, 22 filtration steps. This drawback hampers the practical application of PAC in real-world drinking water treatment.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Adsorption of Mixtures of Per- and Polyfluoroalkyl Substances in Water by Chemically Modified Activated Carbon

Ilango,

Jiang,

Zhang

et al. 2023

ACS EST Water

View full text Add to dashboard Cite

Chemical modifications of granular activated carbon (GAC) and powdered activated carbon (PAC) are necessary for enhanced removal of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in water. Herein, we synthesized and tested goethite (α-FeOOH)-coated GAC and PAC for the adsorption of mixtures of 13 PFAS (9 short- and long-chain PFAAs, GenX, and 3 precursors) from water at an initial concentration of 10 μg/L for each. Among the sorbents tested, modified PAC (MPAC) had excellent adsorption compared to pristine PAC and GAC and modified GAC (MGAC). Based on the isotherms, the maximum adsorption capacity of MPAC toward total PFAS removal was 234 mg/g. Detailed characterizations revealed that the adsorption performance of MPAC was due to its powdered nature, which enabled a shorter diffusion path and rapid mass transfer in the internal pores of this sorbent in addition to the electrostatic and hydrophobic interactions. Results obtained from this study provide valuable insights and knowledge for properly modifying GAC and PAC to address the critical challenges associated with PFAS, especially those associated with short-chain compounds.

show abstract

“…Additionally, it is unclear at this stage whether these materials are able to retain PFAS precursors that have attracted increasing concerns in recent years in aqueous solutions. Furthermore, the process of producing carbon-based materials is highly energy intensive and has drawn scrutiny and attention recently in terms of greenhouse gas emissions . Compared to carbon-based materials, ion exchange resins have been reported to be less cost-effective and biosorbents exhibited lower adsorption capacity …”

Section: Introductionmentioning

confidence: 99%

“…Adsorbents for PFAS mainly include carbon-based materials, , ion exchange resins, , biosorbents, and clay-based materials. , Activated carbons (ACs), including granular and powdered AC (GAC and PAC), carbon nanotubes (CNTs), and biochar, are the main carbon-based materials for PFAS adsorption, of which powdered AC and CNTs showed high adsorption capacities. , The nonpolar functional groups of carbon-based adsorbents contribute to hydrophobic PFAS adsorption . Carbon-based materials, however, have encountered two critical issues that are well-recognized: namely, slow adsorption kinetics and much lower efficiency in removing short-chain PFAS than long-chain ones . Additionally, it is unclear at this stage whether these materials are able to retain PFAS precursors that have attracted increasing concerns in recent years in aqueous solutions.…”

Section: Introductionmentioning

confidence: 99%

Surfactant-Modified Clay for Adsorption of Mixtures of Per- and Polyfluoroalkyl Substances (PFAS) in Aqueous Solutions

Jiang

Zhang

Ilango

et al. 2022

ACS Appl. Eng. Mater.

View full text Add to dashboard Cite

Per- and polyfluoroalkyl substances (PFAS) are persistent, bioaccumulative, and ubiquitous contaminants that are harmful to both humans and ecosystem health. To remove PFAS effectively and efficiently from the aqueous environment, a clay-based adsorbent was synthesized via the modification of montmorillonite by a cationic surfactant cetyltrimethylammonium chloride (CTAC). Through the coexposure adsorption tests with organic dyes and PFAS mixtures, the optimal ratio of CTAC to cation exchange capacity (CEC) was identified. The optimal modified clay exhibited drastically improved adsorption performance, achieving 100% removal efficiency of the PFAS mixture consisting of nine short- and long-chain PFAAs, GenX, and three precursors at initial concentrations of the parts per billion (ppb) level. Additionally, the modified clay outperformed other commercial adsorbents with respect to adsorption performance. The adsorption kinetic data of all PFAS, which were well described by the pseudo-second-order model, suggested an expeditious adsorption process and an adsorption behavior dependent on the initial concentration and carbon chain length. Among the three examined adsorption isotherms, the Sips model combining Langmuir and Freundlich models showed the best fitting correlation, indicating that multiple interactions might be involved in the adsorption process. This hypothesis was supported by characterizations showing that the modified clay possessed physicochemical properties favorable for electrostatic interactions and hydrophobic interactions.

show abstract

Can porous carbons be a remedy for PFAS pollution in water? A perspective

Cited by 19 publications

References 56 publications

Advancing PFAS Sorbent Design: Mechanisms, Challenges, and Perspectives

Advancing PFAS Sorbent Design: Mechanisms, Challenges, and Perspectives

Enhanced Adsorption of Mixtures of Per- and Polyfluoroalkyl Substances in Water by Chemically Modified Activated Carbon

Surfactant-Modified Clay for Adsorption of Mixtures of Per- and Polyfluoroalkyl Substances (PFAS) in Aqueous Solutions

Contact Info

Product

Resources

About