The adsorption or loading of anions onto extruded based peat activated charcoal has been studied by potential measurements in a flow through cell. Loading rates are in the order F- < Cl- < Br- < I -< C03z' < CN- < Ag(CN)z < Au(CN)Z and favour the softer ions. Charcoal adopts more positive potentials and has improved anion loading in acid solution. An oxidation- reduction mechanism for anion loading is supported by the potential measurements and Evans diagrams are used to depict the reactions.