Laboratory experiments on dispersive transport across interfaces: The role of flow direction

Journal Article · Wed Apr 01 04:00:00 EDT 2009 · Water Resources Research

DOI:https://doi.org/10.1029/2008WR007342· OSTI ID:971638

Berkowitz, B; Cortis, A; Dror, I; Scher, H

We present experimental evidence of asymmetrical dispersive transport of a conservative tracer across interfaces between different porous materials. Breakthrough curves are measured for tracer pulses that migrate in a steady state flow field through a column that contains adjacent segments of coarse and fine porous media. The breakthrough curves show significant differences in behavior, with tracers migrating from fine medium to coarse medium arriving significantly faster than those from coarse medium to fine medium. As the flow rate increases, the differences between the breakthrough curves diminish. We argue that this behavior indicates the occurrence of significant, time-dependent tracer accumulation in the resident concentration profile across the heterogeneity interface. Conventional modeling using the advection-dispersion equation is demonstrated to be unable to capture this asymmetric behavior. However, tracer accumulation at the interface has been observed in particle-tracking simulations, which may be related to the asymmetry in the observed breakthrough curves.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: Earth Sciences Division
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 971638
• Report Number(s): LBNL-2368E
• Journal Information: Water Resources Research, Journal Name: Water Resources Research Vol. 45; ISSN WRERAQ; ISSN 0043-1397
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
ASYMMETRY
FLOW RATE
POROUS MATERIALS
SIMULATION
TRANSPORT