Adsorption of perfluoroalkyl acids by carbonaceous adsorbents: Effect of carbon surface chemistry

Zhi, Yue; Liu, Jinxia

doi:10.1016/j.envpol.2015.03.019

Cited by 101 publications

(51 citation statements)

References 34 publications

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“…Moreover, PFOS has a higher log K ow (5.26) than PFOA (4.59; Deng et al, ), which indicates that the sulfonic group is more hydrophobic than the carboxylic group even though they have same carbon chain length (Deng et al, ). PFOA and PFOS have the same carbon chain length, but PFOS contains eight fluorinated carbon and PFOA has seven which results in stronger hydrophobic character in PFOS (Appleman et al, ; Merino et al, ; Zhi & Liu, ; Zhou, Deng, Zhang, et al, ). In addition, it is reported that the PFOS molecule has higher polarizability than the PFOA molecule (PFOS: 19.12 Å 3 molecule −1 ; PFOA: 16.26 Å 3 molecule −1 ; Zhi & Liu, ).…”

Section: Resultsmentioning

confidence: 99%

“…PFOA and PFOS have the same carbon chain length, but PFOS contains eight fluorinated carbon and PFOA has seven which results in stronger hydrophobic character in PFOS (Appleman et al, ; Merino et al, ; Zhi & Liu, ; Zhou, Deng, Zhang, et al, ). In addition, it is reported that the PFOS molecule has higher polarizability than the PFOA molecule (PFOS: 19.12 Å 3 molecule −1 ; PFOA: 16.26 Å 3 molecule −1 ; Zhi & Liu, ). Therefore, the van der Waals interactions with the GAC surface induced by PFOS are likely stronger than PFOA (Zhi & Liu, ).…”

Section: Resultsmentioning

confidence: 99%

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Influence of groundwater conditions and co‐contaminants on sorption of perfluoroalkyl compounds on granular activated carbon

Siriwardena

Crimi

Holsen

et al. 2019

Remediation Journal

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Per and polyfluoroalkyl substances (PFAS) are emerging and persistent organic pollutants that have been detected in many environmental media, humans, and wildlife. A common method to effectively remove PFAS from water is adsorption by activated carbon. Preliminary sorption experiments were conducted using five characterized Calgon Corporation coal‐based granular activated carbon (GAC; F100, F200, F816, F300, and F400), one coconut‐based GAC (CBC‐OLC 12 × 30), and one Jacobi Corporation coal‐based GAC (Omni‐G 12 × 40). Sorption of four representative PFAS onto each GAC was measured to select the most favorable carbon sources. F400 and CBC were chosen based on their performance in preliminary PFAS sorption experiments and contrasting properties. Freundlich and Langmuir isotherm models were developed for perfluorooctanoic acid (PFOA) and perfluorooctanoic sulfonate (PFOS) at an initial concentration of 1 mg/L. Sorption capacities were determined for PFOA and PFOS individually and in the mixture. Individual compounds showed higher sorption than when present in the mixture for both PFOA and PFOS. PFOS showed higher sorption than PFOA both individually and in the mixture and F400 showed higher sorption capacity than CBC. The presence of co‐contaminants (kerosene, trichloroethylene, and ethanol), and variations in groundwater conditions (pH, presence of SO 4 − 2 anions, naturally occurring organic matter, and iron oxides) demonstrated limited impact on the sorption of PFAS onto GAC under the experimental conditions tested.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Influence of groundwater conditions and co‐contaminants on sorption of perfluoroalkyl compounds on granular activated carbon

Siriwardena

Crimi

Holsen

et al. 2019

Remediation Journal

View full text Add to dashboard Cite

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“…The adsorption capacity for PFOS and PFOA has been shown to be related to GAC surface area, pore size, and surface chemistry (Ochoa‐Herrera & Sierra‐Alvarez, ; Zhi & Liu, ). Some studies have found powdered activated carbon (PAC) outperforms GAC (Rattanaoudom, Visvanathan, & Boontanon, ; Yeung et al., ), although this finding has not been universal (Sun et al., ; Zhi & Liu, ). It is important to note that PAC is typically not reactivated and, therefore, spent PAC may not be reclaimed by the manufacturer.…”

Section: Water Treatment Technologiesmentioning

confidence: 99%

“…It is important to note that PAC is typically not reactivated and, therefore, spent PAC may not be reclaimed by the manufacturer. Wood‐ and bamboo‐based GAC have been shown to outperform coal‐based material with adsorption decreasing at both acidic and alkaline pH (Deng et al., ; Zhi & Liu, ). There are also forms of coconut shell carbon (e.g., overactivated coconut carbon) that have been engineered to improve PFAA removal over the past two years.…”

Section: Water Treatment Technologiesmentioning

confidence: 99%

“…Other adsorbents which have been shown to adsorb PFASs include chars, ash, and carbon nanotubes (Chen, Xia, Wang, Qiao, & Chen, ), activated carbon fibers (Zhi & Liu, , ), hydrotalcite (Rattanaoudom et al., ), Ambersorb (Zhi & Liu, ), imprinted polymers (Yu, Deng, & Yu, ), modified cotton and rice husk (Deng et al., ; Deng et al., ), porous aromatic frameworks (Luo, Zhao, Liu, & Ren, ), and cross‐linked cyclodextrins (Xiao, Ling, et al., ).…”

Section: Water Treatment Technologiesmentioning

confidence: 99%

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A review of emerging technologies for remediation of PFASs

Ross

McDonough

Miles

et al. 2018

Remediation Journal

408

268

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The need for remediation of poly‐ and perfluoroalkyl substances (PFASs) is growing as a result of more regulatory attention to this new class of contaminants with diminishing water quality standards being promulgated, commonly in the parts per trillion range. PFASs comprise >3,000 individual compounds, but the focus of analyses and regulations has generally been PFASs termed perfluoroalkyl acids (PFAAs), which are all extremely persistent, can be highly mobile, and are increasingly being reported to bioaccumulate, with understanding of their toxicology evolving. However, there are thousands of polyfluorinated “PFAA precursors”, which can transform in the environment and in higher organisms to create PFAAs as persistent daughter products. Some PFASs can travel miles from their point of release, as they are mobile and persistent, potentially creating large plumes. The use of a conceptual site model (CSM) to define risks posed by specific PFASs to potential receptors is considered essential. Granular activated carbon (GAC) is commonly used as part of interim remedial measures to treat PFASs present in water. Many alternative treatment technologies are being adapted for PFASs or ingenious solutions developed. The diversity of PFASs commonly associated with use of multiple PFASs in commercial products is not commonly assessed. Remedial technologies, which are adsorptive or destructive, are considered for both soils and waters with challenges to their commercial application outlined. Biological approaches to treat PFASs report biotransformation which creates persistent PFAAs, no PFASs can biodegrade. Water treatment technologies applied ex situ could be used in a treatment train approach, for example, to concentrate PFASs and then destroy them on‐site. Dynamic groundwater recirculation can greatly enhance contaminant mass removal via groundwater pumping. This review of technologies for remediation of PFASs describes that: GAC may be effective for removal of long‐chain PFAAs, but does not perform well on short‐chain PFAAs and its use for removal of precursors is reported to be less effective; Anion‐exchange resins can remove a wider array of long‐ and short‐chain PFAAs, but struggle to treat the shortest chain PFAAs and removal of most PFAA precursors has not been evaluated; Ozofractionation has been applied for PFASs at full scale and shown to be effective for removal of total PFASs; Chemical oxidation has been demonstrated to be potentially applicable for some PFAAs, but when applied in situ there is concern over the formation of shorter chain PFAAs and ongoing rebound from sorbed precursors; Electrochemical oxidation is evolving as a destructive technology for many PFASs, but can create undesirable by‐products such as perchlorate and bromate; Sonolysis has been demonstrated as a potential destructive technology in the laboratory but there are significant challenges when considering scale up; Soils stabilization approaches are evolving and have been used at full scale but performance need to be assessed usin...

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Chemically Tailored Metal‐Organic Frameworks for Enhanced Capture of Short‐ and Long‐Chain Per‐ and Polyfluoroalkyl Substances from Water

Loukopoulos,

Marugán‐Benito,

Raptis

et al. 2024

Adv Funct Materials

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Per‐ and polyfluoroalkyl substances (PFAS) are emerging as bioaccumulative and toxic water pollutants, posing a large threat to human and aquatic organisms. This threat is aggravated by their extreme persistence to common degradation methods. Adsorption is regarded as the most conventional method to treat these contaminants, however, existing sorbents present considerable limitations on performance. The development of more efficient PFAS adsorbents is therefore of urgent need. The class of metal‐organic frameworks (MOFs) can hold great promise for these purposes, featuring porous materials with high tailoring potential. Herein, a series of functionalized Zr‐MOFs have been designed with boosted capacities for the adsorption of short‐ and long‐chain perfluorinated carboxylic acids of environmental interest. The approach relies on chemistry‐based concepts to introduce targeted post‐synthetic modifications that promote PFAS···MOF interactions, specifically through coordinative bonding and hydrophobic effects. In particular, the framework TFA‐MOF‐808 (TFA = trifluoroacetic acid) displays the highest capture capacities reported for MOF materials in this pollutant class. Mechanistic studies, assisted by advanced synchrotron characterization techniques and theoretical calculations, support a ligand exchange process occurring during the adsorption phenomena. The results demonstrate the potential of this design approach in developing advanced PFAS sorbents with optimal performance.

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Adsorption of perfluoroalkyl acids by carbonaceous adsorbents: Effect of carbon surface chemistry

Cited by 101 publications

References 34 publications

Influence of groundwater conditions and co‐contaminants on sorption of perfluoroalkyl compounds on granular activated carbon

Influence of groundwater conditions and co‐contaminants on sorption of perfluoroalkyl compounds on granular activated carbon

A review of emerging technologies for remediation of PFASs

Chemically Tailored Metal‐Organic Frameworks for Enhanced Capture of Short‐ and Long‐Chain Per‐ and Polyfluoroalkyl Substances from Water

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