Silica gel ion exchange resins for the selective removal of lead and cadmium ions from aqueous liquids

In an ion exchange process to selectively remove the metals, lead and cadmium, from aqueous liquids containing the ions of these metals wherein these liquids are contacted with an ion exchange resin for a period of time sufficient for the ion exchange resin to complex with the lead and cadmium ions in the aqueous liquids and then regenerating the resin to remove and recover the metals from the resin;

• the improvement which comprises using as the ion exchange resin an amorphous silica gel having a surface area of at least 100M.sup.2 /g having at least 10% of its surface silanol groups reacted with a triethoxy silane selected from the group consisting of Bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane and N-[3-(triethoxysilyl)propyl]-4,5-dihydroimidazole.