scholarly journals Modified clays reduce leaching of per‐ and polyfluoroalkyl substances from AFFF ‐contaminated soils

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Chenyang Wang ◽  
Bei Yan ◽  
Gabriel Munoz ◽  
Sébastien Sauvé ◽  
Jinxia Liu
2021 ◽  
Author(s):  
Georgios Niarchos ◽  
Dan Berggren Kleja ◽  
Lutz Ahrens ◽  
Fritjof Fagerlund

<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>


2013 ◽  
Vol 62 (2) ◽  
pp. 373-386 ◽  
Author(s):  
György Czira ◽  
László Simon ◽  
György Vincze ◽  
József Koncz ◽  
Gyula Lakatos

Magyarországon a robbanóanyaggal és lőszerszármazékokkal szennyezett területek kármentesítése környezetvédelmi és nemzetgazdasági érdek. Egy hazai lőtérről, illetve lőszer-megsemmisítő telepről vett talajban 900 mg·kg−1 ólom- és 133 mg·kg−1 rézszennyeződést mértünk. A fitoextrakció célja, hogy a növényi szervekbe helyezzük át a nehézfémeket, lecsökkentve ezzel a mobilis, toxikus elemkészletet a szennyezett talajokban. Megvizsgáltuk, hogy egy lőszerszármazékokkal szennyezett talajba, illetve ólommal mesterségesen elszennyezett talajba kijuttatott kelátképzőszerekkel (EDTA, EGTA, citromsav) indukálható-e, megnövelhető-e a növényi szervek Pb- és Cu-akkumulációja?Tenyészedény-kísérletünkben kukoricát neveltünk a fenti ólommal és rézzel elszennyezett lőtéri talajon, illetve a közelben gyűjtött szennyezetlen talajt mesterségesen szennyeztük el 100 mg·kg-1 ólommal. Míg a kontroll (kelátképzővel nem kezelt) szennyezett talajon fejlődő kukorica gyökerében 554 μg·g−1 ólom volt mérhető, addig az EDTA hatására a gyökerekben 4611 μg·g−1-ra (több mint nyolcszorosára), a hajtásokban pedig 158-ról 302 μg·g−1-ra (91%-kal) nőtt az ólomkoncentráció. Mindkét változás statisztikailag szignifikánsnak bizonyult. Az EGTA a Cufelvételt serkentette; a kontrollkultúrák gyökerében 516 μg·g−1, a kezelt kultúrákban viszont 1063 μg·g−1 értéket mértünk (ez kétszeres szignifikáns növekmény). A hajtásokban 69%-kal, 29,9-ról 50,7 μg·g−1-ra emelkedett a réztartalom, ez azonban nem bizonyult statisztikailag szignifikánsnak. A citromsav az ólom hajtásokba történő áthelyeződését nem indukálta, rézfelvétel-serkentő hatása csak a gyökerekben volt szignifikáns.Tenyészedény-kísérleteink alapján kijelenthető, hogy elsősorban az EDTA, illetve részben az EGTA a talajba kijuttatva mobilisabbá, könnyebben felvehetővé teszi az ólmot és a rezet, elősegítve ezzel e két toxikus elem növényekben történő akkumulációját. Szabadföldi körülmények között is feltételezhető, hogy a növények betakarításával a toxikus elemek egy része eltávolítható a szennyezett talajból.


Author(s):  
I.А. Degtyareva ◽  
◽  
I.А. Shaydullina ◽  
А.Ya. Davletshina ◽  
T.Yu. Motina ◽  
...  
Keyword(s):  

2020 ◽  
Author(s):  
Azhagiya Singam Ettayapuram Ramaprasad ◽  
Phum Tachachartvanich ◽  
Denis Fourches ◽  
Anatoly Soshilov ◽  
Jennifer C.Y. Hsieh ◽  
...  

Perfluoroalkyl and Polyfluoroalkyl Substances (PFASs) pose a substantial threat as endocrine disruptors, and thus early identification of those that may interact with steroid hormone receptors, such as the androgen receptor (AR), is critical. In this study we screened 5,206 PFASs from the CompTox database against the different binding sites on the AR using both molecular docking and machine learning techniques. We developed support vector machine models trained on Tox21 data to classify the active and inactive PFASs for AR using different chemical fingerprints as features. The maximum accuracy was 95.01% and Matthew’s correlation coefficient (MCC) was 0.76 respectively, based on MACCS fingerprints (MACCSFP). The combination of docking-based screening and machine learning models identified 29 PFASs that have strong potential for activity against the AR and should be considered priority chemicals for biological toxicity testing.


Author(s):  
Nikolay S. Shulaev ◽  
◽  
Valeriya V. Pryanichnikova ◽  
Ramil R. Kadyrov ◽  
Inna V. Ovsyannikova ◽  
...  

The most essential scientifific and practical task in the area of ecological safety of pipelines operation is the development and improvement of methods of purifification and restoration of oil-contaminated soils. One of the most effificient and cost effective methods is electrochemical purifification, that does not require the use of expensive chemical reagents and soil excavation. However, the consideration of non-uniform contamination of various soil sections is required. The article examines the features of the organization and technological infrastructure for electrochemical purifification of non-uniformly contaminated soils when using a single electrical energy source, a method for calculating the design parameters of the corresponding installation is proposed. Effificient purifification of non-uniformly contaminated soil when using a specifified voltage is possible through the use of different-sized electrodes. For each soil type, the amount of transmitted electric charge required for soil purifification is determined by the concentration of the contaminant. Allocation of cathodes and anodes as parallel batteries and their connection using individual buses is an effective and energy-effificient solution, since an almost-uniform electric fifield is created in an inter-electrode space, thus allowing the reduction of the interelectrode resistance of the medium.


2008 ◽  
Vol 7 (4) ◽  
pp. 379-387 ◽  
Author(s):  
Attar Singh Sheoran ◽  
Vimla Sheoran ◽  
Poonia Poonam
Keyword(s):  

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