Removal of NAPL from columns by oxidation, sparging, surfactant and thermal treatment

Florie Jousse (1) , Olivier Atteia (1) , Patrick Höhener (2) , Grégory Cohen (1)

1 EGID - Environnement, Géo-ingénierie et Développement
2 LCE - Laboratoire Chimie de l'environnement

In this paper, four treatment techniques commonly applied to Volatile Organic Compounds (VOC) removal from soil are compared in column experiments with pure sand containing a residual Light Non- Aqueous Phase Liquid (L-NAPL) contamination. Oxidation is tested through the injection of Fenton reagent, with persulfate, and combined with sparging with the injection of ozone. Surfactant treatment was conducted at low flow rates with Tween®80. Sparging was conducted by air injection but at a low flow rate of 1 mL min1. Finally several columns were thermally treated at a temperature of 80 C. The results showed high removal (>90%) for all techniques used, although only thermal treatment on BTEX (Benzene, Toluene, Ethylbenzene and Xylenes) reached 100% efficiency. The main limiting factors of each technique were: (i) for oxidation, the solubility of the substance limited the removal; (ii) for surfactant both the solubility in the surfactant and the type of surfactant are important; (iii) for sparging, the main factors are contaminant vapor pressure and porous media grain size; (iv) for thermal treatment, the limitation arises from the contaminant vapor pressure and the medium hydraulic conductivity. A comparison with literature data shows that the results are consistent with most of the studies conducted on one technique.

Keywords: Remediation Columns Oxidant Thermal Surfactant Sparging

Domains: Environmental Sciences; Global Changes; Environmental Sciences; Environmental Engineering

Florie Jousse, Olivier Atteia, Patrick Höhener, Grégory Cohen. Removal of NAPL from columns by oxidation, sparging, surfactant and thermal treatment. Chemosphere, 2017, 188, pp.182-189. ⟨10.1016/j.chemosphere.2017.08.163⟩. ⟨hal-01588249⟩