An experimental study of acoustically enhanced NAPL dissolution in porous media

Experimental investigation of acoustically enhanced colloid transport in water-saturated packed columns

“…The acoustic pressure forcing caused an increase in effective interstitial velocity and dispersion at all frequencies for the conservative tracer and the two colloids, with maximum increase at 30 Hz. This enhanced transport and dispersion is consistent with results obtained for non-aqueous phase liquids in the presence of acoustic waves [24,[26][27][28]. In conjunction with colloid-facilitated contaminant transport during conventional pump-and-treat applications, this may lead to reduced aquifer remediation times.…”

“…Other theoretical and experimental results have shown that significant displacement of solutes in saturated porous media results from the propagation of different types of compression waves (e.g., compaction waves and short and long shock waves), even in the absence of background flow [1]. Experimental evidence also shows that acoustic waves can increase both mobilization and dissolution in multi-phase systems (i.e., NAPL/water) [24,[26][27][28]. Thomas and Narayanan [29] showed that solute mass transfer is enhanced by several orders of magnitude when the fluid medium is subject to oscillatory motion, even if there is no net total flow over a cycle of oscillation.…”

“…Thomas and Narayanan [29] showed that solute mass transfer is enhanced by several orders of magnitude when the fluid medium is subject to oscillatory motion, even if there is no net total flow over a cycle of oscillation. Experimental evidence has shown that effluent aqueous DNAPL concentration increased with the application of acoustic pressure waves with the greatest dissolution enhancement occurring at lower frequencies [26]. Furthermore, ganglia that were immobile under steady background flow were mobilized when acoustic pressure was added [27,28].…”

Acoustically Enhanced Ganglia Dissolution and Mobilization in a Monolayer of Glass Beads

“…Experimental studies have shown that acoustic waves enhance dissolved mass transport in saturated porous media (Vogler and Chrysikopoulos, 2002), and also increase dissolution/mass-transfer from single and multicomponent DNAPL ganglia in saturated porous media Vogler and Chrysikopoulos, 2004). Furthermore, several other investigations indicated that vibration of porous media can mobilize DNAPL ganglia (Reddi and Challa, 1994;Reddi and Wu, 1996;Reddi et al, 1998;Roberts et al, 2001).…”

Maximization of wave motion within a hydrocarbon reservoir for wave-based enhanced oil recovery

“…However, since waves at such high frequencies attenuate rapidly with distance, techniques relying on ultrasound waves are not viable for mobilizing oil droplets at the reservoir scale (Roberts and Abdel-Fattah (2009);Roberts et al (2001)). On the other hand, a number of laboratory tests have demonstrated dislodging of oil droplets by using elastic or acoustic wave sources at low frequency ranges: Beckham et al (2010), Roberts and Abdel-Fattah (2009), and Roberts et al (2001 showed that dynamic stress, exerted on a solid rock matrix of a sandstone core at low frequencies (10Hz -100Hz), can release trapped oil droplets; Vogler and Chrysikopoulos (2004), Thomas and Chrysikopoulos (2007) also showed that acoustic waves of frequencies up to 300Hz can remove the non-aqueous phase liquid (NAPL) from porous permeable core samples; Spanos et al (2003) conducted experiments demonstrating that fluid-pressure pulsing at frequencies ranging from 30Hz to 60Hz can increase the oil recovery rate from confined sand packs;…”