An underdrain filtered water collection system includes: a pair of opposing drainpipes, each drainpipe having a plurality of collection drains; and a diffuser screen. The diffuser screen can slide within an outlet in each of the collection drains. A diffuser screen for a pressure vessel containing filter media includes: a screen pipe; a solid plate coupled to a base of the screen pipe; and a winged diffuser arranged around an outer circumference of the solid plate. The winged diffuser includes a plurality of foldable wings. The screen pipe includes a mesh screen having preconfigured interstices therethrough. Feed water flows through the screen pipe where it is directed by an inner surface of the solid plate to flow in a diffused flow through the interstices of the mesh screen and the wings.

A solid-liquid filtration assembly for removing solids from a solid-liquid mixture includes a filter module comprising a pan, to which a screen is attached, and a scraping arm, to which is attached slurry nozzles. A media bed on the screen separates solids from a mixture of a liquid and the solids. Filtrate drains from the pan via a drain tube. A scraping arm removes dewatered solids and soiled media from atop the media bed, forward of the scraping arm. The scraping arm also expels the dewatered solids and the soiled media from the pan, while slurry nozzles deliver the mixture to the media bed aft of the scraping arm.

A gas lift conveyance device moves a slurry through an upwardly extending lifting section of a conduit in communication from a source location at a first pressure to a discharge location at a lesser second pressure. A gas injector of the device injects gas into the conduit through a variable position valve that is controlled by a controller that uses a representative value measured by a sensor as input to a closed loop control algorithm of the controller. The representative value may be a pressure or flow rate that is representative of the gas delivery rate. The device provides: (i) automated control over the delivery rate of slurries; (ii) real time values of air rate, valve position, and pressure; (iii) a reduction of energy input due to optimal use of air; and (iv) a reduction in air pumps stalling or plugging failures.

The present disclosure provides a device, a system, and a method for filtering liquids, in particular for filtering gray water such that it can be reused for multiple purposes. Also provided is an optional step of purifying the liquid with a chemical such that the filtered liquid is also potable.