Try using the only 100% sure way of accomplishing this function. Any organic COMPOUND can be reduced into its elemental/nutritional state by a process called BIOREMEDIATION and using an RNA microbe called ARCHAEA. They do not make a screening material small enough to do the task you ask. The Archaea do their job and are .5 to .005 microns. Any heavy metal compounds are also chelated into their non toxic nutritional state. If in US easy to order. If over seas just ask.