Patent ID: 7238288

Claim:
A method for absorbing an ion from a fluid, comprising; dispersing an organic acid of the formula C a H b O c , where a≧7, b>0 and c>0, in water to form an anion surfactant solution; mixing a divalent-metal cation M(II) containing compound with a trivalent-metal cation M(III) containing compound into said anion surfactant solution to form a precursor solution; heating said precursor solution to form a solid layered double hydroxide product in solution; separating said solid layered double hydroxide product from said solution; calcining said solid layered double hydroxide product to form an absorption material of the formula M(II) x M(III)(OH) 2x+2 (Y/n).zH 2 O, where M(II) is a divalent metal cation, M(III) is a trivalent metal cation, x is a positive number between 1.5 and 12, Y is an anionic surfactant comprising at least 7 carbon atoms, n is a positive integer, and z is a positive number less than 10; and contacting said absorption material with an aqueous solution containing at least one charged ion, said at least one charged ion selected from the group consisting of lead, arsenic, selenium, and combinations thereof.