Biochar and activated carbons preparation from invasive algae Sargassum spp. for Chlordecone availability reduction in contaminated soils

2021 ◽  
pp. 105280
Author(s):  
Ronald Ranguin ◽  
Matthieu Delannoy ◽  
Christelle Yacou ◽  
Corine Jean-Marius ◽  
Cyril Feidt ◽  
...  
Keyword(s):  
Contaminated Soils ◽  
Activated Carbons ◽  
Invasive Algae

Factors influencing the sorption of polycyclic aromatic hydrocarbons, cadmium and mercury to biochars – a surface response methodology approach

2020 ◽  
Author(s):  
Sampriti Chaudhuri ◽  
Gabriel Sigmund ◽  
Hary von Rautenkranz ◽  
Thorsten Hueffer ◽  
Thilo Hofmann
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Organic Carbon ◽  
Carbon Content ◽  
Aromatic Hydrocarbons ◽  
Contaminated Soils ◽  
Activated Carbons ◽  
Water Retention Capacity ◽  
Organic Carbon Content ◽  
Surface Response ◽  
Polycyclic Aromatic

<p>Biochar is a versatile soil additive and CO<sub>2</sub> neutral or negative “green” sorbent. Biochar can improve the soil quality, water retention capacity, and is effective in binding contaminants. Previous studies showed that biochar is a suitable remediation option at sites with residual contamination and that it is particularly favorable in immobilizing organic polycyclic aromatic hydrocarbons (PAHs) and cadmium. To achieve remediation goals, however, careful assessment of the soil geochemistry (pH, background ions, organic carbon content), the nature of the contaminant, and the application rate need to be carried out. We have screened the sorption affinity of 11 different types of biochars and 2 activated carbons for selected heavy metals and ionizable and non-ionizable PAHs. The biochars differed in the starting feedstock material (rice husk, wheat straw pellets, mixed softwood pellets, oil seed rape straw, miscanthus straw pellets), temperature of production (550°C, 700°C), and elemental composition. The target contaminants included acenaphthene, dibenzofuran, carbazole, dibenzothiophene, 2-hydroxybiphenyl, cadmium, and mercury. The sorption of the organic contaminants was driven by the carbon content, specific surface area, and aromatic nature of the biochars. Sorption of cadmium was higher onto biochars with greater inorganic fractions, whereas for mercury no specific trends could be observed. Based on the results of the initial screening, a novel approach to statistically design experiments using the Box-Behnken model was employed for selected biochars. Using this method, experiments were conducted to systematically investigate the influence of four factors (pH, dissolved organic carbon, ionic strength and contaminant concentration) on sorption at three different levels (-1, 0, +1). The results from the surface response modeling approach provides fundamental new insight into the applicability of these biochars at contaminated sites and can help identify scenarios favorable for remediation with biochar. Our results will help in the development of a remediation strategy with an overall low environmental footprint for contaminated soils.</p>

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>

Desorption and Reutilization Studies of Copper and Lead Lons by Activated Carbons Prepared from Ulva Fasciata sp

2012 ◽  
Vol 2 (6) ◽  
pp. 60-63
Author(s):  
R. P. Suresh Jeyakumar ◽  
◽  
Dr. V. Chandrasekaran Dr. V. Chandrasekaran
Keyword(s):  
Activated Carbons ◽  
Ulva Fasciata

Effect of chelants on the lead and copper uptake of maize from contaminated soils

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

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.

Methods of oil-contaminated soils diagnostic

2018 ◽  
pp. 106-109
Author(s):  
I.А. Degtyareva ◽  
◽  
I.А. Shaydullina ◽  
А.Ya. Davletshina ◽  
T.Yu. Motina ◽  
...  
Keyword(s):  
Contaminated Soils

Electrochemical cleaning of soils with different concentrations of oil pollution using a single source of electrical voltage

2020 ◽  
Vol 10 (6) ◽  
pp. 674-680
Author(s):  
Nikolay S. Shulaev ◽  
◽  
Valeriya V. Pryanichnikova ◽  
Ramil R. Kadyrov ◽  
Inna V. Ovsyannikova ◽  
...  
Keyword(s):  
Contaminated Soils ◽  
Oil Pollution ◽  
Cost Effective ◽  
Electrical Energy ◽  
Design Parameters ◽  
Technological Infrastructure ◽  
Chemical Reagents ◽  
Electrode Space ◽  
Soil Excavation ◽  
Interelectrode Resistance

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.

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