Fig. 4
From: Oxidation of arsenite to arsenate on birnessite in the presence of light
Manganese (II) release into solution: the concentration of dissolved Mn2+ released during the oxidation of 470 µM of As(III) by Na-birnessite at pH 5 in the presence of light and dark under oxic and anoxic conditions. Control experiments are also included for Na-birnessite with no As(III) at pH 5 in the presence of light under oxic and anoxic conditions