Air sparging and bioremediation: The case for in situ mixing
- Groundwater Technology, Inc., Englewood, CO (United States)
- Groundwater Technology, Inc., Trenton, NJ (United States)
- Groundwater Technology, Inc., Norwood, MA (United States)
Air sparging has sparked considerable controversy in the remediation industry. Some feel air sparging is a significant advance in remedial technology, whereas others feel that air sparging is a very limited technology. A central question in this debate is the presence (or lack thereof) of groundwater mixing during air sparging. Groundwater mixing is important to overcome the diffusion limitations of sparging caused by air channeling and effectively deliver oxygen for in situ bioremediation. Possible mechanisms of groundwater mixing include physical displacement, capillary interactions of air and water, frictional drag, makeup of evaporative loss, thermal convection, and movement of fines. Physical groundwater displacement and groundwater movement resulting from capillary pressure gradients are the two most likely and most commonly effective mechanisms. An important question is the relative degree of groundwater mixing during nonsteady-state and steady-state sparging. Evidence indicates that mixing occurs primarily during nonsteady-state air sparging. Because groundwater mixing is important to overcome the diffusion limitations of air sparging, it is important to operate sparging systems to maximize mixing. Field data show that pulsed sparging, which emphasizes the nonsteady-state aspects of air sparging, greatly enhances groundwater mixing.
- OSTI ID:
- 467725
- Report Number(s):
- CONF-950483-; ISBN 1-57477-003-9; TRN: IM9721%%153
- Resource Relation:
- Conference: 3. international in situ and on-site bioreclamation symposium, San Diego, CA (United States), 24-27 Apr 1995; Other Information: PBD: 1995; Related Information: Is Part Of In situ aeration: Air sparging, bioventing, and related remediation process; Hinchee, R.E. [ed.] [Battelle Memorial Inst., Columbus, OH (United States)]; Miller, R.N. [ed.] [Air Force Center for Environmental Excellence, Brooks AFB, TX (United States)]; Johnson, P.C. [ed.] [Arizona State Univ., Tempe, AZ (United States)]; PB: 630 p.; Bioremediation, Volume 3(2)
- Country of Publication:
- United States
- Language:
- English
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