Journal article
Transport of barrel and spherical shaped colloids in unsaturated porous media
Journal of contaminant hydrology, Vol.180(C), pp.69-79
09/2015
Handle:
https://hdl.handle.net/2376/102057
PMID: 26275396
Abstract
Model colloids are usually spherical, but natural colloids have irregular geometries. Transport experiments of spherical colloids may not reflect the transport characteristics of natural colloids in porous media. We investigated saturated and unsaturated transport of colloids with spherical and angular shapes under steady-state, flow conditions. A pulse of negatively-charged colloids was introduced into a silica sand column at three different effective water saturations (Se=0.31, 0.45, and 1.0). Colloids were introduced under high ionic strength of [106]mM to cause attachment to the secondary energy minimum and later released by changing the pore water to low ionic strength. After the experiment, sand was sampled from different depths (0, −4, and −11cm) for scanning electron microscopy (SEM) analysis and colloid extraction. Water saturation affected colloid transport with more retention under low than under high saturation. Colloids were retained and released from a secondary energy minimum with more angular-shaped colloids being retained and released. Colloids extracted from the sand revealed highest colloid deposition in the top layer and decreasing deposition with depth. Pore straining and grain–grain wedging dominated colloid retention.
[Display omitted]
•Transport of spherical and angular colloids was investigated under variably-saturated flow.•Colloid transport was affected by water saturation.•More non-spherical than spherical colloids were retained in 2nd energy minimum.
Metrics
6 Record Views
Details
- Title
- Transport of barrel and spherical shaped colloids in unsaturated porous media
- Creators
- Thorsten Knappenberger - Department of Crop, Soil & Environmental Sciences, Auburn University, Auburn, AL 36849, United StatesSurachet Aramrak - Department of Crop & Soil Sciences, Washington State University, Pullman, WA 99164 and Puyallup, WA 98371, United StatesMarkus Flury - Department of Crop & Soil Sciences, Washington State University, Pullman, WA 99164 and Puyallup, WA 98371, United States
- Publication Details
- Journal of contaminant hydrology, Vol.180(C), pp.69-79
- Academic Unit
- Crop and Soil Sciences, Department of
- Publisher
- Elsevier B.V
- Identifiers
- 99900546548301842
- Language
- English
- Resource Type
- Journal article