Laboratory Study of Air Sparging: Air Flow Visualization

Abstract

Laboratory flow visualization experiments, using glass beads as the porous medium, were conducted to study air sparging, an innovative technology for subsurface contaminant remediation. The purpose of these experiments was to observe how air flows through saturated porous media and to obtain a basic understanding of air plume formation and medium heterogeneity effects. The experiments indicate that air flow occurring in discrete, stable channels is the most probable flow behavior in medium to fine grained water saturated porous media and that medium heterogeneity plays an important role in the development of air channels. Several simulated scales of heterogeneities, from pore to field, have been studied. The results suggest that air channel formation is sensitive to the various scales of heterogeneities. Site‐specific hydrogeologic settings have to be carefully reviewed before air sparging is applied to remediate sites contaminated by volatile organic compounds.

Effects of air injection on flow through porous media: Observations and analyses of laboratory‐scale processes

“…40, W09203, doi:10.1029/2003WR002960, 2004 aerobic biodegradation [e.g., Reddy and Adams, 2001;Brooks et al, 1999;Ahlfeld et al, 1994;Ji et al, 1993;Marley et al, 1992;Bruell et al, 1997].…”

Numerical modeling of kinetic interphase mass transfer during air sparging using a dual‐media approach

“…On the basis of reports that typical gas channels are several grain diameters [Ji et al, 1993;Clayton, 1998;, the average gas channel was assumed to have a diameter of about 3 mm. Note that here the "channels" are actually the coarse-grained media, and they will include both gas and water during air sparging [see, e.g., Clayton, 1998].…”

Estudo do fluxo de ar em solos usando a técnica de injeção de ar em modelos físicos bidimensionais.

“…Vários autores como Ji et al (1993) e Baker e Benson (2007) mostraram que aumentando a vazão ou a pressão de injeção, a saturação de ar também aumenta O uso de múltiplos poços de injeção produz aparentemente uma superposição dos raios de influência, mas isso não implica que todo o volume de água seja alcançado com a mesma eficiência (AHLFELD; DAHMANI; JI, 1994).…”

“…The increase in the pressure of injection during the experiments induced the formation of more air channels causing an increase in the size of the zone of influence. (Ji et al (1993) Estudos teóricos e experimentais da zona de influência em solos heterogêneos são necessários para um bom entendimento do método, do espaçamento dos poços e da profundidade de injeção. Vários autores, tais como: (BAKER e BENSON, 2007;BROOKS, WISE e ANNABLE, 1999;ELDER e BENSON, 1999;JI et al, 1993;) utilizaram bolinhas de vidro visando caracterizar o comportamento do fluxo em um solo granular.…”

“…(Ji et al (1993) Estudos teóricos e experimentais da zona de influência em solos heterogêneos são necessários para um bom entendimento do método, do espaçamento dos poços e da profundidade de injeção. Vários autores, tais como: (BAKER e BENSON, 2007;BROOKS, WISE e ANNABLE, 1999;ELDER e BENSON, 1999;JI et al, 1993;) utilizaram bolinhas de vidro visando caracterizar o comportamento do fluxo em um solo granular. Já autores como: (CHAO, ONG e HUANG, 2008;PETERSON et.…”