group iii metal a group iv metal or a group v metal for instance the active component 6 may be a hydroxide or an oxide of iron zirconium lanthanum cerium titanium aluminum tin silver zinc mercury bismuth copper antimony tungsten molybdenum the active component 6 may also include mixtures of metal hydroxides or mixtures of metal oxides that are incorporated in the matrix 4 for sake of example only a mixture of ferric hydroxide lanthanum hydroxide and titanium hydroxide may be present in the matrix 4 by utilizing the mixture of metal hydroxides or mixtures of metal oxides the adsorption medium 2 may be tailored to remove specific oxidation states of arsenic selenium or antimony depending on which constituents are present in the feed stream for sake of example only one metal mixture may be more specific to remove as iii compounds while a second metal mixture may have increased specificity for as v compounds the metal mixture may also be tailored to selectively remove constituents in the presence of other potentially competing anions such as phosphates or nitrates to produce the adsorption medium 2 having a metal hydroxide as the active component 6 at least one metal compound may be dissolved in a solvent to form a metal solution the metal compound may be a metal salt.