To provide a treating material for waste photographic solutions for obtaining the waste photographic solutions adapted to the environmental regulations by removing microorganisms and contamination by-products, thereby controlling the proliferation of the microorganisms and a treatment method.

This method of manufacturing an oxidizing material comprises dispersing a metal or metal compound which is capable of oxidizing the products to the oxidized and (or) the microorganisms to be removed in the form of colloid into an aqueous solution of an inorganic aluminosilicate polymer capable of forming an inorganic gel, then gelatinizing the aluminosilicate to the gel by addition of a base. The metal is preferably silver in the form of powder capable of forming the colloid in dispersion. This oxidizing material is particularly effective in the treatment of a photographic bath, more particularly a washing bath arranged behind a fixing process step.