The efficiency of road run-off filtration facilities based on ion-exchange materials is reduced by pollutants which are transported bound to particles. To quantify the factors governing particle transport phenomena, a simplified model consisting of quartz sand-filled columns representing the filter/soil was set up. Suspensions of artificial clays, cold water-extracted natural clays, and real run-off were used as model effluents. Five experiments were performed: breakthrough of a natural soil suspension, remobilization of a natural soil suspension after ionic strength-drop, the same two experiments with a suspension of the artificial clay mineral Laponite, and the remobilization of run-off accumulated on a column at high ionic strength with an ionic strength down-gradient. Short-interval effluent fractions were analysed by flow-field-flowfractionation (F4) to obtain the size distributions of the colloids present. The size distributions of subsequent fractions were then plotted in a staggered arrangement to give three-dimensional graphs that are time- and particle size-resolved. With this method the subsequent release of different agglomerate sizes formed on the column could be shown for the artificial clay mineral, questioning its use as a model colloid. The combined particle size- and time-resolved plots proved to be a powerful tool for monitoring colloidal solids in column effluents.
Colloidal transport and agglomeration in column studies for advanced run-off filtration facilities - particle size and time resolved monitoring of effluents with flow-field-flowfractionation
R. Siepmann, F. von der Kammer, U. Förstner; Colloidal transport and agglomeration in column studies for advanced run-off filtration facilities - particle size and time resolved monitoring of effluents with flow-field-flowfractionation. Water Sci Technol 1 December 2004; 50 (12): 95–102. doi: https://doi.org/10.2166/wst.2004.0700
Download citation file: