The Effects of Wetting on Transport of Organics in Groundwater

We investigated the effects of altered surface chemistries on fluid saturations, flow characteristics, and sorption properties in model porous media. Two distinct lines of inquiry were pursued. The first was to evaluate effects of surface chemistry on wettability and pressure/saturation relationships of chemically modified silica. The second line of inquiry was to modify the surface chemistry of a natural zeolite and determine the effects of such modification on sorption of organic chemicals from solution.

We found that we could create silica surfaces of different wettabilities which were stable for hundreds of hours in aqueous systems. We used these modified silicas to determine pressure/saturation relationships for water/oil systems and related the observations to measurements of wettability. We showed that we could use quaternary ammonium cations to predictably alter the sorptive properties of natural zeolites.

Our model experiments showed that basic information on surface characteristics can be used to predict changes successfully in fluid dynamics and sorption properties of porous media.