Chemical factors influencing colloid-facilitated transport of contaminants in porous media

Environmental Science & Technology
By:  and 



The effects of colloids on the transport of two strongly sorbing solutesa hydrophobic organic compound, phenanthrene, and a metal ion, Ni2+were studied in sand-packed laboratory columns under different pH and ionic strength conditions. Two types of column experiments were performed as follows:  (i) sorption/mobilization experiments where the contaminant was first sorbed in the column under conditions where no colloids were released and mobilized under conditions where colloids were released as a result of ionic strength reduction in the influent; and (ii) transport experiments where the contaminant, dissolved or sorbed on colloids, was injected into columns packed with a strongly sorbing porous medium. In the first type of experiment, contaminant mobilization was significant only when all releasable colloids were flushed from the column. In all other cases, although high colloid particle concentrations were encountered, there was no marked effect on total contaminant concentrations. In the second type of experiment, colloid deposition efficiencies were shown to control the enhancement of transport. The deposition efficiency was a function of the pH (for a high organic content sand) and of the contaminant concentration (for a charged species such as Ni2+).

Publication type Article
Publication Subtype Journal Article
Title Chemical factors influencing colloid-facilitated transport of contaminants in porous media
Series title Environmental Science & Technology
DOI 10.1021/es9600643
Volume 31
Issue 3
Year Published 1997
Language English
Publisher American Chemical Society
Contributing office(s) Toxic Substances Hydrology Program
Description 9 p.
First page 656
Last page 664
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