Abstract: To separate a small alga such as Dunaliella from a containing liquid, a filter substrate is provided with a surface coat including a large alga such as Spirulina. The Dunaliella and some liquid are run through the Spirulina and the substrate and so are separated with some Spirulina content.

Abstract: An apparatus for removing excess liquid and contaminants from a belt filter cake includes a perforated main belt extending over a separation drum. An anti-wear permeable belt has one portion lying against part of the main belt supported by the separation drum. There are exterior suction headers and chambers effective through the anti-wear belt and main belt and a main suction box within the separation drum for cake recovery where the main belt is in contact therewith. Wash water nozzles are within the separation drum directed toward the exterior suction headers and chambers.

Abstract: A separation drum for suction recovery at high concentration of fine particles, such as algae, removed from dilute liquid medium by a belt filter has a thin, perforated wall rotatably mounted on a substantially horizontal, cantilevered beam fixed on a base. A pair of rings or hubs engage the separation drum at opposite ends. One ring is rotatably supported on rollers mounted on the beam, and the other ring is rotatably supported on a bearing mounted on a shaft extending from the beam to a removable end pedestal on the base. A number of interior rollers, also supported from the beam, engage the interior surface of the drum. A conduction or suction box is disposed on the beam or built into the beam in juxtaposition with the upper, interior portion of the separation drum to receive and carry away material passing through the perforated drum wall. A main belt extends around the exterior of the separation drum wall and around a filtration drum within a liquid medium containing algae.

Abstract: A solids remover for high rate algae ponds has a longitudinally extending pond within which there is a transversely extending settling basin, the settling basin having separate zones for the settlement of different solids. A carriage is supported for movement across the settling basin and carries pumping means. A nozzle arrangement on the inlet to the pumping means is effective to retrieve solids from any one or more of the separate zones and discharges the retrieved solids to a stationary solids receiver in any position of the carriage.

Abstract: From a water medium, a harvester recovers algae useful as animal feed. The harvester has a preferably endless, movable belt screen. A coating device puts a first coating of long fibers (such as glass fiber or asbestos mixed with paper fiber) onto one side of the belt screen. A container of algae in water discharges onto the first coating permitting much of the water to pass through it and the belt screen but holding back the algae largely as a second coating on the fibers. A second screen having finer openings than the first screen is disposed against the second coating. This second screen has openings large enough to pass the algae but small enough to hold back the fibers. A suction is applied to the second screen causing the algae and entrained water to move therethrough. Concurrently, a washer directs a stream through the first screen and through the first coating and so washes off the second coating of algae, the fine screen holding the fibers behind.