A clarifier in a wastewater treatment plant is provided with a submerged launder for effluent, the launder preferably having an integral density current baffle and scum baffle. In one embodiment an existing launder is modified, with its vertical leg replaced with a sloped plate defining launder conduit triangular in cross section, and with a sloping portion of the plate forming a density current baffle. Openings in the sloped plate permit entry of effluent liquid, and the liquid level in a clarifier is controlled without an overflow weir plate. In another form submerged pipe with entry holes serves as the launder, with support brackets integral with a density current baffle. A third form of the launder is a box formed beneath the shelf of an existing internal launder in the clarifier, again with a density current baffle extending down from the box. In another version an existing launder is covered and sealed, and holes are drilled through the launder wall to admit effluent. A submerged launder avoids problems of algae buildup and the need for algae sweeps or frequent cleaning of the launder.

In a wastewater treatment system, a suction duct clarifier is converted to a suction pipe clarifier without penetrating existing concrete at the base of the tank. An elevated sludge collection box is added, positioned on the center column to rotate with rake arms, and a series of sludge riser pipes extend from the rake arms up into the sludge collection box for sludge delivery by hydraulic pressure differential. A sludge discharge downpipe is provided within the center/influent column for delivery of sludge from the collection box, and at the bottom of this pipe, above the tank floor, the discharge pipe exits through an opening in the center/influent column. At the outside of this opening is a sludge transfer box that receives sludge exiting the discharge pipe and conveys it down through the existing floor opening and to the existing under-floor RAS return pipe.

A treatment device for stormwater is provided that comprises a container which in use contains a growing medium and a hydrodynamic separator located within the container. The hydrodynamic separator comprises a separation chamber, an inlet duct extending from the outside of the container to the separation chamber, a solids outlet; and a liquid outlet that opens into the container. In use, liquid flow containing solids enters the separation chamber through the inlet duct and is caused to swirl within the separation chamber, thereby causing solids to exit the separation chamber through the solids outlet and liquid to exit the separation chamber through the liquid outlet and to flow into the growing medium.

A screen decanter for screening solids from waste water in a waste water treatment system comprising a drain manifold and a plurality of cylindrical cartridges mounted to the drain manifold, each of the cylindrical cartridges having an outer screen defining a cavity. Each of the cartridges includes a drain standpipe disposed within the cavity in communication with the drain manifold. Each drain standpipe includes a plurality of patterned openings arranged in at least one row along the length and partial circumference thereof and preferably comprises three rows of patterned openings, each row being disposed at a 120 rotational angle from the adjacent row of patterned openings. Each drain standpipe is disposed at a 30 rotational angle from its neighbor drain standpipe such that no row of patterned openings in any of said drain standpipes faces directly at any other row of patterned openings in any other drain standpipe.

A system is provided for separating particulates dispersed within a base fluid wherein at least one of the particulates and the base fluid is an organic liquid. The system relies on a microfluidic separation device comprising a microchannel in fluid communication across a microporous body with a collection chamber. Particulates and a portion of the base fluid traverse the microporous body under the influence of an external force field and are collected in the collection chamber. A first fluid flow having a first flow rate through the microchannel together with the microporous body operationally generate a second fluid flow within the collection chamber as base fluid and particulates traverse the microporous body and enter the collection chamber, and as base fluid re-traverses the microporous body and re-enters the microchannel, the second fluid flow having a flow rate which is a fraction of the first flow rate.

In a wastewater treatment system, a suction duct clarifier is converted to a suction pipe clarifier without penetrating existing concrete at the base of the tank. An elevated sludge collection box is added, positioned on the center column to rotate with rake arms, and a series of sludge riser pipes extend from the rake arms up into the sludge collection box for sludge delivery by hydraulic pressure differential. A sludge discharge downpipe is provided within the center/influent column for delivery of sludge from the collection box, and at the bottom of this pipe, above the tank floor, the discharge pipe exits through an opening in the center/influent column. At the outside of this opening is a sludge transfer box that receives sludge exiting the discharge pipe and conveys it down through the existing floor opening and to the existing under-floor RAS return pipe.

A waste water separation vessel is provided having a wedge shaped body with an internal water containing volume. The body is configured to trap FOG and wastes within the body allowing water to pass through the body. At least one top facing access port to allow access to the internal volume of the body is provided and the wedge shaped body tapers outwardly from top to bottom to define a larger bottom area than a top area. The side walls include vertically oriented strengthening ribs which define intervening indentations, and each lower end of the vertically oriented ribs is connected to a generally horizontal beam which defines closed bottom ends on the indentations. When the vessel is buried in the ground the wedge shaped body and the closed bottom indentations interact with the ground to help oppose any buoyancy forces acting on the buried body.

A method of separating heavy water from normal through application of acoustic pressure shock waves to a fluid including heavy water and normal water and recovering separated normal water.

A method of desalinating water through application of acoustic pressure shock waves to a slush to separate ice crystals from brine and recovering desalinated water from the separated ice crystals.

Acoustic pressure shock waves are applied to a membrane in a fluid to prevent attachment of or dislodge biological or solid matter for membrane cleaning or desalination with a membrane.