Fig. 7 The effect of adsorbed anions on the electrophoretic mobility (EM) of Al oxide. (a) Effect of CO₃, SO₄, and SeO₄. (b) Effect of SO₄ in single-anion systems and in binary-anion systems with CO₃. (c) Effect of organic anions. (d) Effect of organic anions in binary-anion systems with SO₄. The blank samples contain only the background salt NaCl. All systems contained a background salt concentration of 0.011 M NaCl