Dissolved and colloidal contaminant transport in a partially clogged fracture

Journal Article · Fri Apr 01 00:00:00 EST 1994 · Water Resources Research; (United States)

DOI:https://doi.org/10.1029/93WR03555· OSTI ID:6956504

Kessler, J H ^[1]; Hunt, J R ^[2]

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1. EPRI, Palo Alto, CA (United States)
2. Univ. of California, Berkeley, CA (United States)

A water-saturated fracture, partially clogged with porous material coating the fracture surfaces, is considered. Fluid flow and contaminant transport in this fracture are significantly altered relative to an unclogged fracture. Analytical expressions are developed for the water velocities in the clogged and the unclogged regions in the fracture and the asymptotic longitudinal dispersion coefficient for the system. For highly adsorbing dissolved contaminants or large colloids, the slow diffusion within the porous region causes enhanced dispersion. In a standard tracer test, colloidal contaminants will arrive earlier than dissolved tracers for either one of two reasons: (1) colloids confined to the unclogged portion of the fracture will have a larger average velocity or (2) colloids that can diffuse into the porous region have very low Brownian diffusivities, resulting in a large longitudinal dispersion due to the inverse relationship between Taylor dispersion and Brownian diffusion. The average velocity or asymptotic longitudinal dispersion coefficient can be orders of magnitude greater than that for a molecular tracer. 46 refs., 8 figs.

• OSTI ID: 6956504
• Journal Information: Water Resources Research; (United States), Vol. 30:4; ISSN 0043-1397
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AQUIFERS
POROSITY
COLLOIDS
DIFFUSION
ENVIRONMENTAL TRANSPORT
GROUND WATER
FLOW MODELS
FLUID FLOW
GEOLOGIC FRACTURES
VELOCITY
DISPERSIONS
GEOLOGIC STRUCTURES
HYDROGEN COMPOUNDS
MASS TRANSFER
MATHEMATICAL MODELS
OXYGEN COMPOUNDS
WATER
540220* - Environment
Terrestrial- Chemicals Monitoring & Transport- (1990-)