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Solute Transport Through a Stony Soil
Author(s) -
Schulin R.,
Wierenga P. J.,
Flühler H.,
Leuenberger J.
Publication year - 1987
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1987.03615995005100010007x
Subject(s) - retardation factor , soil water , flux (metallurgy) , dispersion (optics) , leaching (pedology) , chemistry , infiltration (hvac) , volumetric flow rate , soil science , mineralogy , thermodynamics , environmental science , physics , chromatography , organic chemistry , column chromatography , optics
Movement of tritium and Cl ‐ was studied through undisturbed, unsaturated columns of a Rendoll soil (Eutrochreptic rendoll) containing between 50 and 55% by volume of stones. The columns, 30 cm in diameter and 50 cm long, were leached at a steady flow rate varying from 0.16 to 41 cm/d. Breakthrough curves from these stony soils were smooth and mostly symmetrical, especially for the lowest flux. Based on an analysis with the classical two‐parameter convection‐dispersion equation, it was found that the dispersion coefficient was linearly related to pore water velocity with an average dispersivity of about 4 cm. The difference between the retardation factors for Cl ‐ and tritium averaged 0.16 pore volumes. Using a four‐parameter transport equation with exchange between mobile and immobile liquid phases, an immobile water fraction of 15% was found, independent of the leaching rate. The four‐parameter model provided no better fit to the experimental data than the two‐parameter model for the lowest flux and only slightly better fits for all the other cases. This indicates that nonequilibrium conditions between mobile and immobile phases were of minor importance in modeling solute transport through this stony soil.