In: Journal of Hydrology and Hydromechanics, vol. 66, no. 3
Nasrollah Sepehrnia - Olga Fishkis - Bernd Huwe - Jörg Bachmann
Detaily:
Rok, strany: 2018, 271 - 278
Kľúčové slová:
Soil water repellency; Hydrophobic colloids; C18; Sessile drop; Repellency index.
URL originálneho zdroja: http://www.ih.sav.sk/jhh
O článku:
The coupled transport of pollutants that are adsorbed to colloidal particles has always been a major topic for
environmental sciences due to many unfavorable effects on soils and groundwater. This laboratory column study was
conducted under saturated moisture conditions to compare the hydrophobic character of the suspended and mobilized
colloids in the percolates released from a wettable subsoil and a water repellent topsoil. Both soils with different organic
matter content were analyzed for wettability changes before and after leaching using sessile drop contact angles as well
as water and ethanol sorptivity curves, summarized as repellency index. Hydrophobicity of the effluent suspensions was
assessed using the C18 adsorption method. Water repellency level of the repellent soil decreased after leaching but remained
on a lower level of water repellency, while, the wettable soil remained wettable. The leached colloids from the
repellent soil were predominantly hydrophilic and the percentage of the hydrophobic colloid fraction in the effluent did
not systematically changed with time. Total colloid release depended on soil carbon stock but not on soil wettability. Our
results suggest that due to the respective character of transported colloids a similar co-transport mechanism for pollutants
may occur which does not depend explicitly on soil wettability of the releasing horizon, but could be more affected by
total SOM content. Further studies with a wider range of soils are necessary to determine if the dominant hydrophilic
character of leached colloids is typical. Due to the mostly hydrophilic colloid character we conclude also that changes in
wettability status, i.e. of wettable subsoil horizons due to the leachate, may not necessarily occur very fast, even when
the overlaying topsoil is a repellent soil horizon with a high organic matter content.
Ako citovať:
ISO 690:
Sepehrnia, N., Fishkis, O., Huwe, B., Bachmann, J. 2018. Natural colloid mobilization and leaching in wettable and water repellent soil
under saturated condition. In Journal of Hydrology and Hydromechanics, vol. 66, no.3, pp. 271-278. 0042-790X (until 2019) .
APA:
Sepehrnia, N., Fishkis, O., Huwe, B., Bachmann, J. (2018). Natural colloid mobilization and leaching in wettable and water repellent soil
under saturated condition. Journal of Hydrology and Hydromechanics, 66(3), 271-278. 0042-790X (until 2019) .