Abstract: A method of generating an adsorbent product for use in magnetic separation of contaminants from an influent liquid comprises the steps of: (i) mixing at least one micro-organism with the liquid in a chemostat vessel; (ii) magnetically separating a magnetic fraction of liquid from the vessel from a non-magnetic fraction (iii) returning the magnetic fraction to the vessel; and (iv) collecting precipitated material from the vessel for use as the adsorbent product. In an embodiment, a solution comprising heavy metals is fed to a chemostat containing sulphur-generating micro-organisms, iron, sulphates and a nutrient compound together with N.sub.2. Liquid is drawn off to a high gradient magnetic separator where the non-magnetic fraction containing decontaminated liquid is separated off; the slurry is removed for use as an adsorbent. Sulphide generating micro-organisms are listed. Dy and Er salts or complexes can be added, as can other specified micro-organisms.

Abstract: A method for high grade magnetic separation using a matrix having one or more magnetizable matrix elements, wherein each element comprises a pair of poles aligned substantially parallel to a direction of flow of a slurry fluid containing particles to be separated, whereby a rear fluid vortex attributable to the upstream pole extends substantially to meet a front fluid vortex attributable to the downstream pole.

Abstract: An apparatus and a method are described for separating magnetizable particles from a fluid in which they are suspended. The apparatus comprises a separating chamber having an inlet and an outlet for permitting fluid to enter and leave the separating chamber, a matrix of a plurality of ferromagnetic filaments arranged substantially parallel to one another and to the general direction of flow of fluid through the matrix and disposed in the separating chamber, magnet means for establishing a high intensity magnetic field in the separating chamber perpendicular to the general direction of flow of the fluid through the matrix, and removal means for removing magnetizable particles attracted to the matrix within the separating chamber.