Keren, R.
Singer, M.J.

This study was conducted to determine if the effectiveness of hydroxy-Al and -Fe polymers in stabilizing the hydraulic conductivity of smectite-sand mixture increases with their charge density. The effect of pH 5.5 and 7.5 on the saturated hydraulic conductivity (HC) of Na/Ca-smectite-sand mixtures (5% clay and 95% sand) and in the presence of hydroxy-Al and -Fe polymers was studied by leaching with various NaCl-CaCl2 solutions. The effect of pH on the charge density of the hydroxy polymers explained their effectiveness in stabilizing the system at the lower pH. The lower HC of the clay-sand mixture in the presence of hydroxy-Fe polymers suggests that the aggregates with this polymer are weaker than those with hydroxy-Al polymers. -from Authors