The researchers tested different types of geosynthetic clay liners (GCLs) with organobentonite additives to see how they affect water flow and contaminant transport. They found that adding organobentonite increased water flow through the GCLs, especially at higher concentrations. However, the ability of GCLs to block organic contaminants remained similar to GCLs with conventional bentonite. This suggests that replacing some conventional bentonite with organobentonite can improve the GCLs' ability to slow down the movement of organic pollutants.