0000000000206072
AUTHOR
Nicolas Fatin-rouge
showing 11 related works from this author
Shear-thinning fluids for gravity and anisotropy mitigation during soil remediation in the vadose zone
2018
Abstract Surfactant foam has been proposed as an effective treatment fluid for in situ environmental remediation of soils. In the vadose zone, it could improve treatment homogeneity, but its use remains challenging. To better understand and predict foam formation and propagation in vadose zone, we studied them in 24 soils with wide range of properties (including permeability: 2 10−12 to 3.3 10−9 m2). Foam rheology showed to be complex and mostly influenced by soil permeability and grading. Below 2 10−11 m2, foam propagation velocity was not influenced by permeability. Conversely, slight shear thinning to Newtonian behavior was observed for higher permeabilities. Benefits for remediation in …
Targeted delivery of hydrogen for the bioremediation of aquifers contaminated by dissolved chlorinated compounds.
2019
Dihydrogen (H2) gas injection is a promising option to enhance the reductive biodehalogenation of contaminants in groundwater. However, it is challenging to ensure its targeted delivery at the right places in plumes, and for the long times required for bioremediation. In this paper, the ability of surfactant foam to retain H2 in the saturated zone and to enhance its release in the dissolved form was compared to traditional biosparging. H2 gas was injected, either alone, or as foam, in a 2D saturated cell packed with glass beads. This cell was continuously flushed with deoxygenated water to mimic aquifer circulation, and H2 was studied both in terms of gas distribution in the cell and dissol…
Enhanced remedial reagents delivery in unsaturated anisotropic soils using surfactant foam
2018
Abstract Homogeneous delivery of solution of oxidant in unsaturated soils is limited by soil anisotropy and gravity. An innovative injection strategy using foam was developed to improve in situ delivery. Primary foam injection before oxidant solution enhanced both the lateral and uniform delivery of reactant in isotropic and anisotropic (permeability, contamination) soils. The oxidant spread isotropically through the foam water network. This sequential injection heavily improved the delivery radius of influence (ROI), while limiting contact between surfactant and solution of oxidant in order to preserve the selective oxidation of petroleum hydrocarbons contaminant (TPH). Prior foam injectio…
Assessment of flushing methods for the removal of heavy chlorinated compounds DNAPL in an alluvial aquifer.
2017
International audience; Immiscible mobilization and foam flushing were assessed as low surfactant consuming technologies, for the enhanced recovery of dense non-aqueous phase liquid (DNAPL) residual at a site contaminated by heavy chlorinated compounds. Preliminary experiments in well-controlled conditions demonstrated the phenomena involved in these remediation technologies and their limitations. Furthermore, we characterized the technologies according to by their surfactant consumption (per kg of DNAPL recovered) and the final DNAPL saturation reached. Surfactant foam flushing (SFF) produced lower DNAPL saturation than immiscible mobilization, thanks to its higher viscosity. However, its …
Treatment of heavy petroleum hydrocarbons polluted soil leachates by ultrafiltration and oxidation for surfactant recovery
2018
Abstract Surfactant technology can improve the remediation of soils polluted by semivolatile hydrophobic contaminants, like polycyclic aromatic hydrocarbons (PAHs), by enhancing their solubility in water. However, the recovery of surfactant from soil-leachates is critical for the economic feasibility of this treatment technology. To tackle this issue, ultrafiltration (UF) and its combination with permanganate, is reported for the selective recovery of surfactant from wastewater contaminated by a complex mixture of heavy hydrocarbons mainly composed of PAHs. The overall performance of the process including the successive steps of contaminant mobilization in leachates and surfactant recovery …
Compatibility of surfactants with activated-persulfate for the selective oxidation of PAH in groundwater remediation
2017
Abstract Surfactants foam technology can improve the in situ remediation of hydrophobic organic contaminants by enhancing their solubility and the delivery of remediation chemicals. However, the presence of surfactants may impair the effectiveness of the selective oxidation of those contaminants. To tackle the issue, kinetics and selectivity of phenanthrene (PHE) oxidation in aqueous suspensions and its affecting factors including surfactant concentration (CS) and nature, temperature and persulfate (PS) concentration were studied. Significant differences in selectivity were observed between surfactants, reflecting Coulomb interactions with the anionic oxidizers. Lauryl Betaine (LB) stood ou…
Comparative assessment of a foam-based oxidative treatment of hydrocarbon-contaminated unsaturated and anisotropic soils.
2019
Abstract In situ delivery of liquid reagents in vadose zone is limited by soil anisotropy and gravity. The enhanced delivery of persulfate (PS) as oxidant, using a new foam-based method (F-PS) was compared at bench-scale to traditional water-based (W-PS) and surfactant solution-based (S-PS) deliveries. The goal was to distribute PS uniformly in coal tar-contaminated unsaturated and anisotropic soils, both in terms of permeability and contamination. Water was the less efficiently delivered fluid because of the hydrophobicity of the contaminated soils. Surfactant enhanced PS-distribution into contaminated zones by reducing interfacial tension and inverting soil wettability. Regardless of coal…
Contaminant Mobilization from Polluted Soils: Behavior and Reuse of Leaching Solutions
2020
Soil and water contamination by toxic elements or molecules cause risks of chemical pollutions. These pollutions can heavily affect resources and activities of humans and ecosystems. By nature, the remediation of environmental pollutions is a constraint, because its application is hampered by high costs. Soil and groundwater remediation implements a variety of strategies, technologies, and practices to face the diversity and the complexity of every cases. Contaminant recovery is among the three main strategies implemented for the remediation of contaminated soils, and contaminant separation or mobilization by water is widely used for this purpose. As water solubility is the driving force of…
Comparative assessment of a foam-based method for ISCO of coal tar contaminated unsaturated soils
2019
Abstract In situ delivery of liquid reagents in vadose zone is limited by gravity and soil anisotropy. A new foam-based delivery method of persulfate (PS) solutions in unsaturated soils was previously shown to overcome these limitations. The goal of this paper is to demonstrate the efficiency of this method regarding contaminant removal. Hence, the comparative oxidation of 200 mg.kg−1 coal tar artificially contaminated soils with thermally activated PS was carried out after PS-delivery using foam, surfactant solution and pure water. The foam-based method was compared in unfavorable conditions to the reference methods. Especially, in the latter, soil and oxidant solutions were thoroughly mix…
A new foam-based method for the (bio)degradation of hydrocarbons in contaminated vadose zone
2020
International audience; An innovative foam-based method for Fenton reagents (FR) and bacteria delivery was assessed for the in situ remediation of a petroleum hydrocarbon-contaminated unsaturated zone. The surfactant foam was first injected, then reagent solutions were delivered and propagated through the network of foam lamellae with a piston-like effect. Bench-scale experiments demonstrated the feasibility of the various treatments with hydrocarbon (HC) removal efficiencies as high as 96 %. Compared to the direct injection of FR solutions, the foam-based method led to larger radii of influence and more isotropic reagents delivery, whereas it did not show any detrimental effect regarding H…
Controlled treatment of a high velocity anisotropic aquifer model contaminated by hexachlorocyclohexanes
2020
International audience; Xanthan gels were assessed to control the reductive dechlorination of hexachlorocyclohexanes (HCHs) and trichlorobenzenes (TCBs) in a strong permeability contrast and high velocity sedimentary aquifer. An alkaline degradation was selected because of the low cost of NaOH and Ca(OH)2. The rheology of alkaline xanthan gels and their ability to deliver alkalinity homogeneously, while maintaining the latter, were studied. Whereas the xanthan gels behaved like non-Newtonian shear-thinning fluids, alkalinity and Ca(OH)2 microparticles had detrimental effects, yet, the latter decreased with the shear-rate. Breakthrough curves for the NaOH and Ca(OH)2 in xanthan solutions, ca…