Embodiments of a gravity filter for potable water comprise a loose filter bed comprising ion exchange resin particles and activated carbon particles, and a porous non-woven filter substrate disposed downstream of the loose filter bed, wherein the porous non-woven filter substrate comprises an impregnated heavy metal scavenger.

Embodiments of a gravity filter for potable water comprise a loose filter bed comprising ion exchange resin particles and activated carbon particles, and a porous non-woven filter substrate disposed downstream of the loose filter bed, wherein the porous non-woven filter substrate comprises an impregnated heavy metal scavenger.

Underdrain units in a sand medium or dual medium filtration system include efficient air, water and combined air/water cleaning. Air, water or both are delivered in backflow direction from a very low position on the underdrain unit, as well as water from a higher position, so as to effectively remove blocking contaminants on the outside the underdrain unit and in the surrounding filter media.

A filter media retainer has a plate having a first end wall, a second end wall, and a pair of longitudinal sidewalls connected to opposing sides of the first end wall and the second end wall. The plate has a top surface opposite a bottom surface. A plurality of hopper-shaped compartments are formed on the top surface and have a first sloped wall and a second sloped wall angled toward the first sloped wall in a direction from the top surface toward the bottom surface. The plate further has a top sidewall on the top surface of the plate separating adjacent hopper-shaped compartments from each other. The plate further has at least one first slot extending through at least one of the first sloped wall and the second sloped wall, and at least one second slot extending through the top sidewall.

A filter media retainer has a plate having a first end wall, a second end wall, and a pair of longitudinal sidewalls connected to opposing sides of the first end wall and the second end wall. The plate has a top surface opposite a bottom surface. A plurality of hopper-shaped compartments are formed on the top surface and have a first sloped wall and a second sloped wall angled toward the first sloped wall in a direction from the top surface toward the bottom surface. The plate further has a top sidewall on the top surface of the plate separating adjacent hopper-shaped compartments from each other. The plate further has at least one first slot extending through at least one of the first sloped wall and the second sloped wall, and at least one second slot extending through the top sidewall.

Systems and methods of eliminate filter air locks by maintaining a constant water table at the water head layer of the filter. The constant water table eliminates air locks in the filter as the filter drains. Water flows from the water head layer through a filtration medium in a filter cartridge, and the filtered water is output from a water outlet at the top of the cartridge. For a water table retention filter, where the water (or other liquid) being filtered, is re-directed to the top of the filter to the water head layer to avoid drawing air into the filter. Unfiltered water drains down the center of the filter to the water head layer and then flows up through the filter and is directed out near or at the top of the filter.

Systems and methods of eliminate filter air locks by maintaining a constant water table at the water head layer of the filter. The constant water table eliminates air locks in the filter as the filter drains. Water flows from the water head layer through a filtration medium in a filter cartridge, and the filtered water is output from a water outlet at the top of the cartridge. For a water table retention filter, where the water (or other liquid) being filtered, is re-directed to the top of the filter to the water head layer to avoid drawing air into the filter. Unfiltered water drains down the center of the filter to the water head layer and then flows up through the filter and is directed out near or at the top of the filter.

A device for treating water for household use designed so as to be temporarily coupled to the mouth of a faucet to allow the continuous supply of treated water and the water to be treated being guided radially through the inside thereof. The device is formed by means of coupling a cylindrical receptacle to an upper closing element, where the receptacle supports, on the inside thereof, a paddle blind on which a hollow, cylindrical-shaped membrane is supported, where the membrane accumulates a filter bed therein. The inner wall of the receptacle is provided with ribs that extend longitudinally so as to define channels through which the treated water flows. The upper closing element is provided with grooves for the inflow of water to be treated, on which sealing means are supported for the coupling to the faucet.

A device for treating water for household use designed so as to be temporarily coupled to the mouth of a faucet to allow the continuous supply of treated water and the water to be treated being guided radially through the inside thereof. The device is formed by means of coupling a cylindrical receptacle to an upper closing element, where the receptacle supports, on the inside thereof, a paddle blind on which a hollow, cylindrical-shaped membrane is supported, where the membrane accumulates a filter bed therein. The inner wall of the receptacle is provided with ribs that extend longitudinally so as to define channels through which the treated water flows. The upper closing element is provided with grooves for the inflow of water to be treated, on which sealing means are supported for the coupling to the faucet.

Devices and methods associated therewith for facilitating movement, removal and/or installation of components from treatment units (e.g., water treatment units and wastewater treatment units). The treatment unit can take the form of a granular media filter (e.g., upflow filter, downflow filter or bi-flow filter) or a sludge collection basin. One preferred device is one or more floats facilitating safe removal of components of a treatment unit. The float(s) can be operably associated with an air scour system of a water filter to remove the air scour system from a granular media filter bed. The float(s) can be operably associated with a collection grid of a sludge collection container facilitating safe removal of the collection grid from the sludge collection container. Another preferred device is a flexible piping/conduit operably connected to a pressurized air source and an air scour system to assist in removal/installation of the air scour system.