In a method for separating low density particles from feed slurries, a bubbly mixture is formed in a downcomer and issues into a mid region in a chamber. An inverted reflux classifier is formed by parallel inclined plates below the mid region allowing for efficient separation of low density particles which rise up to form a densely packed foam in the top of the chamber, and denser particles which fall downwardly to an outlet.

A flotation circuit (1) is characterised in that it comprises a sparger (8) having a sparging mix conduit or chamber (45); and a tube (31) comprising a flexible perforated membrane disposed within the sparging mix conduit or chamber (45). The tube (31) is configured to receive an aerated fluid (27) comprising a combination of sparger water (13), reagent (17), and sparger air or gas (21) therein, shear the aerated fluid (27) upon passing of the aerated fluid (27) through the flexible perforated membrane of the tube (31), and disperse sheared aerated fluid (27) into the sparging mix conduit or chamber (45) where it is combined with incoming feed slurry (2) or diluted incoming feed slurry (4) moving within the sparging mix conduit or chamber (45) to form reagentized aerated slurry (29) for feeding a flotation apparatus (30).

A nanoflotation system used to separate suspended solids or large settling or floating solids from water, waste water or liquids. This is accomplished through the use of submerged membranes, in combination with a number of design components comprising froth flotation, gravity settling, pre coating of the submerged membranes, spacing, of the membranes to facilitate flotation of solids to the surface or to the bottom of the containment chamber holding the submerged membranes, and membrane structures which use large diameter hollow fiber or tubular membranes and/or large pore opening membrane materials.

A method of purifying a metal nanostructure composition containing desired nanostructures and undesired nanostructures. The method includes providing a solution within which metal nanostructures have been synthesized including desired and undesired nanostructures. The solution includes polyol and has a viscosity. The method includes diluting the solution with a dilutant to lower the viscosity of the solution and provide a diluted solution. The method includes sedimenting the undesired nanostructures from the diluted solution. The method includes collecting the supernatant with the desired nanostructures and retaining the undesired nanostructures inside the sedimentation device. In an example, such is via a sedimentation device, which is a special tray system designed with grooved bottoms to retain the undesired nanostructures.

The methods and systems provide for the improvement in the separation of different portions of solids particles, such as bacteria, from a process stream. The methods use gas and control of fluid flow within a tank zone to provide for separation that is more selective.