Figure 2From: Adsorption of dissolved aluminum on sapphire-c and kaolinite: implications for points of zero charge of clay mineralsEffect of aluminum on the zeta-potential of sapphire-c in 1 mM NaCl. Open squares: in absence of added aluminum, full squares: after addition of aluminum (concentration of 3 μM), diamonds and triangles: after replacing the 500 ml solution from the previous experiment by 1 mM NaCl, and subsequent solution exchange.Back to article page