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.

A filter system having a filter media retainer seal includes: at least one underdrain block having a top wall, a bottom wall, and a pair of side walls extending between the top wall and the bottom wall; a filter media retainer mounted onto the top wall of the at least one underdrain block; and at least one rib positioned between the underdrain block and the filter media retainer. The at least one rib forms a seal between the underdrain block and the filter media retainer, and prevents filter media from entering the underdrain block. The at least one rib can be monolithically formed to the at least one underdrain block. Alternatively, the at least one rib is monolithically formed to the filter media retainer. The rib is crushable and/or it bites into a surface on the adjoining part to reduce or eliminate the need for a separate sealant.

A modular drainage filtration apparatus comprising a filtration container having an open-ended structure with a shape determined by the number of walls used during assembly, each wall being formed from a generally flat sheet of a rigid material and comprising a flat body portion with a plurality of formed tabs and an upper and lower overhanging portion, the walls being assembled to form a filtration container enclose an interior region and having open and opposite upper and lower faces and a plurality of filtration units each comprising a flat filter stage configured to be placed within a filtration container.

A modular drainage filtration apparatus comprising a filtration container having an open-ended structure with a shape determined by the number of walls used during assembly, each wall being formed from a generally flat sheet of a rigid material and comprising a flat body portion with a plurality of formed tabs and an upper and lower overhanging portion, the walls being assembled to form a filtration container enclose an interior region and having open and opposite upper and lower faces and a plurality of filtration units each comprising a flat filter stage configured to be placed within a filtration container.

Utilizing mobile walls, a transportable (or stationary) low cost, low carbon footprint process and apparatus with a granular filter media dry cell (for filter or bed) for dewatering particulate solids from liquid. The mobile wall structures can be made of a rigid structure constructed of new or preferred salvaged materials, assembled, with watertight joints, used, disassembled and stored for redeployment. The walls are set in a keyway utilizing whatever soil composition is available. The walls can be used in the previous Deskins filters as old wall replacement or new wall construction. The invention utilizes a generator that is not dependent upon site or local electricity thus can be operated in any location. All parts can be engineered, fabricated according to the design of the Quick-Dry Filter Dewatering Mobile Process and Apparatus, packed in shipping containers and be readily available for any immediate need.

Utilizing mobile walls, a transportable (or stationary) low cost, low carbon footprint process and apparatus with a granular filter media dry cell (for filter or bed) for dewatering particulate solids from liquid. The mobile wall structures can be made of a rigid structure constructed of new or preferred salvaged materials, assembled, with watertight joints, used, disassembled and stored for redeployment. The walls are set in a keyway utilizing whatever soil composition is available. The walls can be used in the previous Deskins filters as old wall replacement or new wall construction. The invention utilizes a generator that is not dependent upon site or local electricity thus can be operated in any location. All parts can be engineered, fabricated according to the design of the Quick-Dry Filter Dewatering Mobile Process and Apparatus, packed in shipping containers and be readily available for any immediate need.

A modular drainage filtration apparatus comprising a filtration container having an open-ended structure with a shape determined by the number of walls used during assembly, each wall being formed from a generally flat sheet of a rigid material and comprising a flat body portion with a plurality of formed tabs and an upper and lower overhanging portion, the walls being assembled to form a filtration container enclose an interior region and having open and opposite upper and lower faces and a plurality of filtration units each comprising a flat filter stage configured to be placed within a filtration container.

Provided is a continuous circulation sand filter including a filtering barrel filled with a sand filtering layer, an inflow tube for introducing raw water into the filtering barrel, a treated water discharge part for discharging treated water purified by passing the raw water through the sand filtering layer from a lower end of the sand filtering layer to an upper end thereof, an air lift tube for transferring contaminated sand, located in the lower end of the sand filtering layer, from a lower part of the filtering barrel to an upper part thereof, a transfer water discharge filter contacting the air lift tube to discharge transfer water moved upward together with sand through the air lift tube and trap the sand and a foreign substance, a descent guide tube downwardly moving the sand and the foreign substance moved to the upper part of the filtering barrel through the air lift tube, and a foreign substance separation tube suctioning the downwardly moving foreign substance to remove the foreign substance from the downwardly moving sand, and discharging the foreign substance.

Provided is a continuous circulation sand filter including a filtering barrel filled with a sand filtering layer, an inflow tube for introducing raw water into the filtering barrel, a treated water discharge part for discharging treated water purified by passing the raw water through the sand filtering layer from a lower end of the sand filtering layer to an upper end thereof, an air lift tube for transferring contaminated sand, located in the lower end of the sand filtering layer, from a lower part of the filtering barrel to an upper part thereof, a transfer water discharge filter contacting the air lift tube to discharge transfer water moved upward together with sand through the air lift tube and trap the sand and a foreign substance, a descent guide tube downwardly moving the sand and the foreign substance moved to the upper part of the filtering barrel through the air lift tube, and a foreign substance separation tube suctioning the downwardly moving foreign substance to remove the foreign substance from the downwardly moving sand, and discharging the foreign substance.