Devices and methods associated with these devices for significantly reducing or eliminating liquid (e.g., water) in a water or wastewater treatment unit above the underdrain from moving downwardly into the underdrain during an air only wash cycle of the treatment unit. The treatment unit can take many forms including but not limited to an upflow filter and a downflow filter. The treatment unit may include a filter bed having one or more layers of filter media supported by gravel above the underdrain. The treatment unit may also include an underdrain having a porous plate, slotted plate or slotted upper structure that obviates the need for gravel. Positive pressure is provided to the underdrain to overcome the downward force of the driving head in the treatment unit to significantly reduce or prevent liquid present in the treatment unit above the underdrain from moving downwardly into the underdrain.

A combined device for sewage deep treatment integrally consists of an open box body (1) divided into multiple water treatment units (29) by a partition wall (27). Each water treatment unit (29) is divided into multiple grids by a partition wall (27′). The lower part of the box body (1) is provided with a conical structure (30) having a discharging door (22) thereunder. The partition wall (27) of the box body (1) has a water blocking belt (33) in the middle thereof, and the box body (1) has rails (31) mounted on two sides of the top thereof, rails (31) having an electric operating platform (2) mounted thereon. The box body (1) is filled with water processing granular carbon (32). Also disclosed is a sewage treatment method employing the combined sewage deep-treatment device. With the method, it is convenient to replace activated carbon, thereby solving the problem that it is difficult for the sewage treatment system to operate continuously and stably when replacing the activated carbon in traditional activated carbon filter.

Embodiments of the present disclosure describe filter agitators, filtration units comprising the filter agitators, methods of using the filter agitators, and the like. In certain embodiments, the filter agitators comprise a plurality of first fins extending outwardly from a central vertical axis and arranged in a plane oriented substantially perpendicular to the central vertical axis, wherein the plurality of first fins is configured to promote laminar flow of a fluid flowing in a first direction and induce turbulent flow of a fluid flowing in a second direction; and optionally a plurality of second fins positioned above the plurality of first fins and extending outwardly from the central vertical axis, wherein the plurality of second fins is configured to induce or further induce turbulent flow.

Embodiments of the present disclosure describe filter agitators, filtration units comprising the filter agitators, methods of using the filter agitators, and the like. In certain embodiments, the filter agitators comprise a plurality of first fins extending outwardly from a central vertical axis and arranged in a plane oriented substantially perpendicular to the central vertical axis, wherein the plurality of first fins is configured to promote laminar flow of a fluid flowing in a first direction and induce turbulent flow of a fluid flowing in a second direction; and optionally a plurality of second fins positioned above the plurality of first fins and extending outwardly from the central vertical axis, wherein the plurality of second fins is configured to induce or further induce turbulent flow.

A method for forming a filter for passing contaminated water using a device and one or more media. The device comprises of one or more elements that are capable of undergoing degradation. The increased area available for flow is obtained by adding a first media to predetermined areas of the device and allowing the elements to undergo degradation to bring about an increase in the area available for passing the contaminated water.

Devices and methods associated with these devices for significantly reducing or eliminating liquid (e.g., water) in a water or wastewater treatment unit above the underdrain from moving downwardly into the underdrain during an air only wash cycle of the treatment unit. The treatment unit can take many forms including but not limited to an upflow filter and a downflow filter. The treatment unit may include a filter bed having one or more layers of filter media supported by gravel above the underdrain. The treatment unit may also include an underdrain having a porous plate, slotted plate or slotted upper structure that obviates the need for gravel. Positive pressure is provided to the underdrain to overcome the downward force of the driving head in the treatment unit to significantly reduce or prevent liquid present in the treatment unit above the underdrain from moving downwardly into the underdrain.

Embodiments of the present invention relate generally to systems and methods for preventing mineral scale deposits in an aircraft water system, and more specifically, within devices and water transport systems, such as coffeemakers and other galley equipment, as well as the water lines themselves.

A method of distributing gas and liquid through an underdrain system includes: a) positioning an underdrain system on a filter floor, the underdrain system comprising at least one underdrain block and filter media positioned on top of the underdrain block; b) distributing gas sufficiently evenly through the underdrain system at a rate of less than 2 scfm/ft.sup.2 by distributing a liquid at a rate of less than 2 gpm/ft.sup.2 concurrently with the gas; c) increasing the distribution rate of the liquid, or increasing the distribution rate of the liquid and the distribution rate of the gas; d) stopping the distribution of gas; e) further increasing the distribution rate of the liquid; and f) decreasing the distribution rate of the liquid. A method of distributing gas and liquid during an upflow filtration mode is also included.