Abstract: Heavy metals are separated from aqueous media containing the same by contacting the said medium with finely divided iron oxide (Fe.sub.3 O.sub.4) and finely divided ferrous sulphide, maintaining said contact until at least a substantial proportion of said heavy metal has become bound to said iron oxide and ferrous sulphide, and then separating the iron oxide and ferrous sulphide having heavy metal bound thereto from the aqueous medium.

Abstract: Paramagnetic metals are separated from aqueous media containing them in low concentration by first fixing the metals on bacterial yeast or other cells so as to render the cells magnetic, and then recovering the cells by a high gradient magnetic separation technique. The metal and the cells are contacted in the presence of a compound which is converted by the cells into a product which interacts with the metal and causes it to become bound to the cells. The process is particularly useful for removing low concentrations of highly toxic metals, e.g. uranium, from industrial effluents containing them.