Sorption of perfluorooctanoic acid, perfluorooctane sulfonate and perfluoroheptanoic acid on granular activated carbon

Zhang, Di; Luo, Qi; Gao, Bin; Chiang, Sheau-Yun Dora; Woodward, David L.; Huang, Qingguo

doi:10.1016/j.chemosphere.2015.10.124

Cited by 145 publications

(51 citation statements)

References 58 publications

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“…This trend occurred in all six waters, despite the groundwaters containing different PFAS species mixtures and initial concentrations. This selective adsorption of PFAS originates from differences in physicochemical properties between longer‐chain and shorter‐chain species (as well as PFCAs and PFSAs) (Appleman et al, ; Du et al, ; Zhang et al, ). For example, PFAS with longer fluorinated carbon chains generally have higher hydrophobicity (indicated in Table by LogK ow and pH corrected LogD ).…”

Section: Discussionmentioning

confidence: 99%

Removing per‐ and polyfluoroalkyl substances from groundwaters using activated carbon and ion exchange resin packed columns

et al. 2020

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Human exposure to per‐ and polyfluoroalkyl substances (PFAS) in drinking water is of growing concern as a result of increasing reports of occurrence and potential regulation. Adsorption of PFAS by granular activated carbon (GAC) or ion exchange (IX) resin is a suitable treatment technique. However, few studies compare PFAS removal in continuous flow GAC or IX adsorption systems using real drinking water sources. In this study, rapid small‐scale column tests (RSSCTs) were used to investigate the effects of PFAS type and chain length on adsorption by GAC and IX resin for six groundwaters used as drinking water supplies. Seven PFAS substances with chain lengths of C4–C9 were detected in the groundwaters with the sum of their concentrations (ΣPFAS) ranging from 156 to 7,044 ng/L. Adsorption capacities (qΣPFAS) were calculated to compare the removal capacity among different sorbents and qΣPFAS values ranged from 10.3 to 228 ng PFAS/mg sorbent after about 100,000 bed volumes treated. Coal‐based GACs had higher adsorption capacity compared with coconutshell‐based GAC, which was likely due to higher mesopore and macropore volumes. IX resins performed better than GAC in removing PFAS, but they were not effective in treating short‐chain perfluorocarboxylic acids (PFCAs). Perfluorosulfonic acids (PFSAs) broke through later than PFCAs with the same chain length. Within PFSA or PFCA classes, shorter‐chain PFAS species always broke through before longer‐chain PFAS. Statistical analysis demonstrated that PFAS with higher hydrophobicity and molecular weight are more amenable to GAC adsorption. Empirical models were developed and predicted PFAS breakthrough. By quantifying PFAS selectivity and removal efficiency, this work provides benchmark data for commercially available treatment technologies and guidance toward specific PFAS classes for which new treatment technologies may be most beneficial.

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Section: Discussionmentioning

confidence: 99%

Removing per‐ and polyfluoroalkyl substances from groundwaters using activated carbon and ion exchange resin packed columns

et al. 2020

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“…The most widely studied techniques are adsorption, membranes, and oxidation processes (Arvaniti and Stasinakis, 2015). The use of activated carbon and anion exchange resins was successfully reported for the retention of PFOA and PFOS (Yu et al, 2009;Zaggia et al, 2016;Zhang et al, 2016). Nanofiltration (NF) and reverse osmosis (RO) processes are of special interest in the separation of PFASs from drinking water sources.…”

Section: Introductionmentioning

confidence: 99%

Efficient treatment of perfluorohexanoic acid by nanofiltration followed by electrochemical degradation of the NF concentrate

2017

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The present study was aimed at the development of a strategy for removing and degrading perfluorohexanoic acid (PFHxA) from industrial process waters at concentrations in the range 60-200 mg L. The treatment train consisted of nanofiltration (NF) separation followed by electrochemical degradation of the NF concentrate. Using a laboratory-scale system and working in the total recirculation mode, the DowFilm NF270 membrane provided PFHxA rejections that varied in the range 96.6-99.4% as the operating pressure was increased from 2.5 to 20 bar. The NF operation in concentration mode enabled a volume reduction factor of 5 and increased the PFHxA concentration in the retentate to 870 mg L. Results showed that the increase in PFHxA concentration and the presence of calcium sulfate salts did not induce irreversible membrane fouling. The NF retentate was treated in a commercial undivided electrochemical cell provided with two parallel flow-by compartments separated by bipolar boron doped diamond (BDD) electrode, BDD counter anode, and counter cathode. Current densities ranging from 20 to 100 A m were examined. The electrochemical degradation rate of PFHxA reached 98% and was accompanied by its efficient mineralization, as the reduction of total organic carbon was higher than 95%. Energy consumption, which was 15.2 kWh m of treated NF concentrate, was minimized by selecting operation at 50 A m. While most of the previous research on the treatment of perfluoroalkyl substances (PFASs) focused on the removal of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), these compounds have been phased out by chemical manufacturers. Our findings are relevant for the treatment of PFHxA, which appears to be one of the present alternatives to long-chain PFASs thanks to its lower bioaccumulative potential than PFOA and PFOS. However, PFHxA also behaves as a persistent pollutant. Moreover, our results highlight the potential of combining membrane separation and electrochemical oxidation for the efficient treatment of PFAS-impacted waters.

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“…[20][21][22] Other conventional technologies are ineffective to PFCAs degradation due to the C─F bond, which is the most durable bond energy in nature (approximately 110 kcal mol −1 ). 21,22 PFCAs were removed from wastewater via adsorption by granular activated carbon (GAC) 23 and powder activated carbon (PAC) 24 ; however, their adsorption capacity is relatively low. Sonolysis-assisted adsorption of PFCAs was reported to enhance the PFCAs removal capability of GAC.…”

Section: Introductionmentioning

confidence: 99%

Tailoring photocatalysts and elucidating mechanisms of photocatalytic degradation of perfluorocarboxylic acids (PFCAs) in water: a comparative overview

Thi

Nguyen

et al. 2020

J of Chemical Tech & Biotech

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A perfluorooctanoic acid (PFOA), as the most important representative of perfluorocarboxylic acids (PFCAs), is environmentally persistent and bioaccumulative. Among treatment techniques for PFOA decomposition, photocatalytic degradation of PFOA has received considerable attention. A series of candidate photocatalytic materials, including TiO2‐, carbonaceous‐, Ga2O3‐, In2O3‐based, etc., have been successfully proposed to eliminate PFOA. Overall, there are two types of mechanisms for photocatalytic degradation of PFCAs, including conventional mechanism and charge transfer mechanism. For a conventional mechanism, the mechanism of PFOA photodegradation over bulk TiO2 via two pathways: photo‐redox and β‐scission. For the charge transfer mechanism, the PFOA degradation pathway in water‐soluble H3PW12O40 is mainly via charge‐transfer excited complex ([PW12O40]3−*). Finally, attention on critical challenges and prospects for photodegradation of PFOA are also intensified. © 2020 Society of Chemical Industry

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Sorption of perfluorooctanoic acid, perfluorooctane sulfonate and perfluoroheptanoic acid on granular activated carbon

Cited by 145 publications

References 58 publications

Removing per‐ and polyfluoroalkyl substances from groundwaters using activated carbon and ion exchange resin packed columns

Removing per‐ and polyfluoroalkyl substances from groundwaters using activated carbon and ion exchange resin packed columns

Efficient treatment of perfluorohexanoic acid by nanofiltration followed by electrochemical degradation of the NF concentrate

Tailoring photocatalysts and elucidating mechanisms of photocatalytic degradation of perfluorocarboxylic acids (PFCAs) in water: a comparative overview

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