Soil and Water Sciences
Winter Seminar
Dr. Qinhong Hu
Department of Earth and Environmental Sciences
The University of Texas at Arlington
- Location: 1002 CHASS Interdisciplinary Building - North
- Time: Wednesday, January 14, 2009, 12:10-1:00 pm
- Campus Map CHASS (INTN)
"Solute Transport in Unsaturated Fractured Rock: Interacting Imbibition, Diffusion, and Sorption Processes"
Abstract: In low-permeability unsaturated fractured rock, water flows predominantly through the interconnected fracture network, with some water imbibing into the neighboring matrix rock. Imbibition (driven by capillary pressure gradient) advectively transports solute from fracture into matrix. Diffusion (driven by concentration gradient) can diffusively transport solute into the matrix. Once in the matrix, sorbing solute can sorb onto matrix rock. All these interacting processes (imbibition, sorption, and diffusion) tend to retard breakthrough of a solute pulse released to the fracture network.
This presentation will discuss how these important processes and factors (water saturation, sample size, and pore connectivity) affect solute transport in unsaturated fractured rock. Innovative techniques [e.g., the unsaturated transport-sorption method, laser ablation coupled with inductively coupled plasma-mass spectrometry (LA_ICP/MS) for micro-scale solid sampling] have been developed to understand and quantify these interacting unsaturated transport processes.