Remediation of per- and polyfluoroalkyl substances (PFASs) contaminated soil and groundwater; evaluating the performance of activated carbon in column tests

2021 ◽  
Author(s):  
Georgios Niarchos ◽  
Dan Berggren Kleja ◽  
Lutz Ahrens ◽  
Fritjof Fagerlund
Keyword(s):  
Activated Carbon ◽  
Contaminated Soils ◽  
Activated Carbons ◽  
Solid Phase ◽  
Total Concentration ◽  
Tracer Tests ◽  
Ultra Performance Liquid Chromatography ◽  
Point Sources ◽  
Treatment Scenario ◽  
Polyfluoroalkyl Substances

<p>Remediation of sites contaminated with per- and polyfluoroalkyl substances (PFASs) is key to reduce the contamination of drinking water sources and subsequent human exposure. PFAS production and use is increasingly being restricted worldwide with a reduction of point sources; however, legacy plumes are still posing a threat due to the persistence of these chemicals against degradation. One of the most widely studied soil remediation techniques for PFASs is stabilisation, which results in the long-term entrapment of the contaminants with the addition of fixation agents in the subsurface, aiming to prevent their leaching from soil to groundwater. In relation to this, the aim of this study was to identify the leaching behaviour of various PFASs in a treatment scenario using activated carbon. Silt loam soil sampled from central Sweden was used, as well as a mixture of the soil with activated carbon at 0.1% w/w. Spiked artificial groundwater was prepared with a mixture of 21 PFASs, at a total concentration of 1.4 μg mL<sup>-1</sup>. The sorption of PFASs to the solid phase was investigated using 15 cm-long column experiments under saturated conditions. Uniform packing of the material was validated through non-reactive tracer tests. The desorption behaviour after treatment was also investigated, by switching the inflow from contaminated to clean water after steady state was achieved. Analysis of the compounds was conducted using ultra performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). Results have shown significantly increased sorption in soil amended with activated carbons compared to the untreated soil. Additionally, there was a positive correlation between the length of the perfluorocarbon chain and sorption efficiency. The study is a step towards increasing our understanding on the efficiency and longevity of stabilisation with activated carbons as a remediation strategy for PFAS-contaminated soils and groundwater.</p>

Column experiments to investigate the fate of per- and polyfluorinated alkyl substances (PFAS) in the subsurface during soil stabilisation with activated carbons.

2020 ◽  
Author(s):  
Georgios Niarchos ◽  
Linnea Georgii ◽  
Dan Berggren Kleja ◽  
Lutz Ahrens ◽  
Fritjof Fagerlund
Keyword(s):  
Activated Carbon ◽  
Contaminated Soils ◽  
Activated Carbons ◽  
Solid Phase ◽  
Sorption Isotherms ◽  
Point Sources ◽  
Column Experiments ◽  
Individual Compound ◽  
Treatment Scenario ◽  
Essential Information

<p>Remediation of sites contaminated with per- and polyfluorinated alkyl substances (PFAS) is key to reduce the contamination of drinking water sources and human exposure. PFAS use is increasingly being restricted worldwide resulting in reduction of point sources; however, legacy plumes are still posing a threat due to the persistence of these chemicals against degradation. One of the most widely studied soil remediation techniques for PFAS is stabilisation (fixation) which results in the long-term entrapment of the contaminants with the addition of activated carbons in the subsurface, aiming to restrict their leaching from soil to groundwater. In relation to this, the aim of this study was to identify the leaching behaviour of various PFAS in a treatment scenario using activated carbons. Silt loam soil sampled from central Sweden was tested, as well as a mixture of the soil with powdered activated carbon (PAC) and colloidal activated carbon (CAC) at 4% w/w concentration. Spiked groundwater was prepared with 21 PFAS, at a concentration of 2.4 μg mL<sup>-1</sup> for each individual compound. The leaching of PFAS from the solid phase was simulated using column experiments in saturated conditions. Additionally, the partitioning behaviour of the substances with increasing concentration was studied through the definition of sorption isotherms for each matrix. For this purpose, batch-shaking tests were performed, and sorption isotherms were defined by fitting the data with the Freundlich and Langmuir models, using five concentration points in the range of 0.1-100 μg mL<sup>-1</sup> for the sum of PFAS. Analysis of the compounds was conducted using high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). Preliminary results from the batch tests show significantly increased sorption in soil amended with activated carbons compared to the untreated soil and a better overall performance of CAC compared to PAC. The study is expected to provide essential information on the efficiency and longevity of stabilisation with activated carbons as a remediation strategy for PFAS-contaminated soils.</p>

scholarly journals Activated Carbon from Rice Husk Biochar with High Surface Area

2020 ◽  
Vol 11 (3) ◽  
pp. 10265-10277
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Rice Husk ◽  
Activated Carbons ◽  
Solid Phase ◽  
Chemical Activation ◽  
High Surface ◽  
High Surface Area ◽  
Array Detector ◽  
Functional Density Theory

Activated carbons derived from rice husk pyrolysis (biochar) were prepared by chemical activation at different biochar/K2CO3 proportions in order to assess its capacity as adsorbent. The activated material was characterized by X-ray diffraction (DRX), Raman spectroscopy, scanning electron microscopy (SEM), the Brunauer, Emmet, and Teller (BET) method. The Barret, Joyner, and Halenda (BJH) method and functional density theory (DFT), presenting interesting texture properties, such as high surface area (BET 1850 m2 g-1) and microporosity, which allow its use as a sorbent phase in solid-phase extraction (SPE) of the main constituents of the aqueous pyrolysis phase. It was demonstrated that the activated carbon (RH-AC) adsorbs different compounds present in from rice husk pyrolysis wastewater through quantitative analysis by high-performance liquid chromatography with a diode-array detector (HPLC-DAD), presenting good linearity (R2 > 0.996) at 280 nm.

scholarly journals Rapid Determination of Per- and Polyfluoroalkyl Substances (PFAS) in Harbour Porpoise Liver Tissue by HybridSPE®–UPLC®–MS/MS

Toxics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 183
Author(s):  
Simone Trimmel ◽  
Kristine Vike-Jonas ◽  
Susana V. Gonzalez ◽  
Tomasz Maciej Ciesielski ◽  
Ulf Lindstrøm ◽  
...  
Keyword(s):  
Liver Tissue ◽  
Solid Phase ◽  
Rapid Determination ◽  
Gradient Elution ◽  
Ultra Performance Liquid Chromatography ◽  
Trace Concentration ◽  
Wet Weight ◽  
Polyfluoroalkyl Substances ◽  
Tissue Matrix

A rapid hybrid solid phase extraction (HybridSPE®) protocol tailored to ultra-performance liquid chromatography–electrospray ionization tandem mass spectrometry (UPLC®–ESI–MS/MS) analysis was developed for the determination of 15 per- and polyfluoroalkyl substances (PFAS) in liver tissue from harbour porpoises (Phocoena phocoena). The HybridSPE® technique has been applied in trace concentration bioanalysis, but it was mainly used for liquid biological media until now. In this study, the protocol was applied on tissue matrix, and it demonstrated acceptable absolute recoveries (%) ranging from 44.4 to 89.4%. The chromatographic separation was carried out using a gradient elution program with a total run time of 4 min. The inter-day method precision ranged from 2.15 to 15.4%, and the method limits of detection (LODs) ranged from 0.003 to 0.30 ng/g wet weight (w.w.). A total of 20 liver samples were analyzed to demonstrate the applicability of the developed method in liver tissue from a wildlife species.

Use of activated carbon to remove undesirable residual amylase from refinery streams

2017 ◽  
pp. 96-103 ◽  
Author(s):  
Gillian Eggleston ◽  
Isabel Lima ◽  
Emmanuel Sarir ◽  
Jack Thompson ◽  
John Zatlokovicz ◽  
...  
Keyword(s):  
Activated Carbon ◽  
High Temperature ◽  
High Performance ◽  
Activated Carbons ◽  
Amylase Activity ◽  
Sugar Industry ◽  
End User ◽  
Customer Complaints ◽  
Carry Over ◽  
Very High

In recent years, there has been increased world-wide concern over residual (carry-over) activity of mostly high temperature (HT) and very high temperature (VHT) stable amylases in white, refined sugars from refineries to various food and end-user industries. HT and VHT stable amylases were developed for much larger markets than the sugar industry with harsher processing conditions. There is an urgent need in the sugar industry to be able to remove or inactivate residual, active amylases either in factory or refinery streams or both. A survey of refineries that used amylase and had activated carbon systems for decolorizing, revealed they did not have any customer complaints for residual amylase. The use of high performance activated carbons to remove residual amylase activity was investigated using a Phadebas® method created for the sugar industry to measure residual amylase in syrups. Ability to remove residual amylase protein was dependent on the surface area of the powdered activated carbons as well as mixing (retention) time. The activated carbon also had the additional benefit of removing color and insoluble starch.

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