Effects of source zone heterogeneity on surfactant-enhanced NAPL dissolution and resulting remediation end-points

Simulation of DNAPL infiltration and spreading behaviour in the saturated zone at varying flow velocities and alternating subsurface geometries

“…Although a lot of research has been done on the topic of DNAPL migration in the saturated zone with respect to small and large scale heterogeneities (Bradford et al 2003;Broholm et al 2005;Dekker and Abriola 2000;Fagerlund et al 2006a;Illangasekare et al 1995;Jawitz et al 2005; Kueper and Frind 1988;Page et al 2007; Rivett and Feenstra 2005;Saenton et al 2002;Bao et al 2004), dissolution processes (Zhu and Sykes 2000;Falta 2003;Falta et al 2005;Fure et al 2006;Rivett and Feenstra 2005;Li et al 2011;Bao et al 2004) and mass flux (Christ et al 2009;Fure et al 2006;Illangasekare et al 2006;Jellali et al 2003;Page et al 2007;Soga et al 2004), there has to the knowledge of the authors, not yet been a distinct focus on enhanced groundwater flow velocities (v w ). The effects of v w up to 1.0-1.5 m/day in combination with heterogeneities have already been investigated with numerical simulations by several research groups.…”

Remediation of Aromatic Hydrocarbons in Low Permeability Soils: Updating the Remediation Decision Tree (Synthesis Study)

“…bioremediation [4][5][6][7][8][9][10][11][12], natural attenuation [13][14][15][16][17][18][19], air-sparging [20][21][22][23][24][25][26][27][28][29][30][31][32], enhanced dissolution [33][34][35][36][37], and excavation. Many other technologies and approaches have been explored.…”

Two-Dimensional Modeling of the NAPL Dissolution in Porous Media: Heterogeneities Effects on the Large Scale Permeabilities and Mass Exchange Coefficient

“…Numerical works of modeling of dissolution ([24] [25] [26] [27]) were carried out. These numerical studies show that: 1) the effectiveness of the dissolution of NAPL depends on the heterogeneity of the aquifer which controls the trapping of NAPL; 2) the deviation of the aqueous phase flow resulting from the heterogeneity and the reduction of relative permeability due to the trapping of NAPL prolongs times of dissolution ( [26]); 3) the morphology of the NAPL source zone, determined by heterogeneity of the porous medium controls dissolution, in other words the precise characterization of the location of the trapped clusters is essential to predict the dissolution flux [27]; 4) when the initial residual saturation is discontinuous, pure water entering in the NAPL source zone can come out again with a certain concentration different or non-equilibrium concentration. Even if in the zones with presence of pollutant, dissolution is of the local equilibrium type, the concentration at the exit can be significantly weaker than equilibrium concentration.…”