A filtering device, a system including the filtering device, and methods of using the filtering device. The filtering device is configured to be arranged inside a fluid to be filtered and comprising at least one main filter and a filter holder supporting the main filter. The filtering device is configured to be moved inside the fluid, in such a way that when the filtering device is moved in a first movement direction, at least one part of the fluid passes through the main filter in a first filtering direction. The filtering device is configured in such a way as to prevent the fluid from passing through the main filter in a second filtering direction opposite to the first filtering direction when the filtering device is moved in a second movement direction opposite to the first movement direction.

A fluid transport assembly includes a substantially cylindrical shell having a first closed end and a second closed end and a tube extending from the first closed end to the second closed end. The tube is substantially aligned with an axis of the shell and provides a passage through the shell. The fluid transport assembly also includes a series of concentric cylindrical filters positioned in the cylindrical shell and extending from the first closed end to the second closed end. The series of concentric cylindrical filters defines an input compartment between the filters and the tube and an output compartment between the filters and the cylindrical shell. The series of concentric filters is structured to remove contaminants from a fluid as the fluid flows through the series of concentric filters from the input compartment to the output compartment.

A movable seal for interfacing between a first surface and a second surface includes a floating portion attached to a non-floating portion by a flexible coupling portion, wherein the non-floating portion is coupled to the first surface by nesting in a groove on the first surface, and wherein the non-floating portion forms a seal between the first and second surfaces when the first surface moves relative to the second surface in a first direction, and wherein the non-floating portion does not form a seal between the first and second surfaces when the first surface moves relative to the second surface in a second opposite direction.

A movable seal for interfacing between a first surface and a second surface includes a floating portion attached to a non-floating portion by a flexible coupling portion, wherein the non-floating portion is coupled to the first surface by nesting in a groove on the first surface, and wherein the non-floating portion forms a seal between the first and second surfaces when the first surface moves relative to the second surface in a first direction, and wherein the non-floating portion does not form a seal between the first and second surfaces when the first surface moves relative to the second surface in a second opposite direction.

A separation tank device may include a holding tank having a tank wall coupled to and extending above a tank base. A base wall may be coupled to and may extend above the tank base. The base wall may form a base upper aperture that is opposingly positioned to the tank base, and a base lower aperture may be formed in the base wall. The device may further include a movable wall having a movable upper aperture and a movable lower aperture, and the movable wall may be movable between a first position and a second position. When the movable wall is in the first position, the movable lower aperture may be positioned above and aligned with the base upper aperture, and when the movable wall is in the second position the movable lower aperture may be unaligned with the base upper aperture.

A movable seal for interfacing between a first surface and a second surface includes a floating portion attached to a non-floating portion by a flexible coupling portion, wherein the non-floating portion is coupled to the first surface by nesting in a groove on the first surface, and wherein the non-floating portion forms a seal between the first and second surfaces when the first surface moves relative to the second surface in a first direction, and wherein the non-floating portion does not form a seal between the first and second surfaces when the first surface moves relative to the second surface in a second opposite direction.

A movable seal for interfacing between a first surface and a second surface includes a floating portion attached to a non-floating portion by a flexible coupling portion, wherein the non-floating portion is coupled to the first surface by nesting in a groove on the first surface, and wherein the non-floating portion forms a seal between the first and second surfaces when the first surface moves relative to the second surface in a first direction, and wherein the non-floating portion does not form a seal between the first and second surfaces when the first surface moves relative to the second surface in a second opposite direction.

A movable seal for interfacing between a first surface and a second surface includes a floating portion attached to a non-floating portion by a flexible coupling portion, wherein the non-floating portion is coupled to the first surface by nesting in a groove on the first surface, and wherein the non-floating portion forms a seal between the first and second surfaces when the first surface moves relative to the second surface in a first direction, and wherein the non-floating portion does not form a seal between the first and second surfaces when the first surface moves relative to the second surface in a second opposite direction.

A movable seal for interfacing between a first surface and a second surface includes a floating portion attached to a non-floating portion by a flexible coupling portion, wherein the non-floating portion is coupled to the first surface by nesting in a groove on the first surface, and wherein the non-floating portion forms a seal between the first and second surfaces when the first surface moves relative to the second surface in a first direction, and wherein the non-floating portion does not form a seal between the first and second surfaces when the first surface moves relative to the second surface in a second opposite direction.

According to various aspects and embodiments, a system and method for two-stage filtration is provided. The system includes an inlet fluidly connectable with wastewater, a first stage filter assembly that is fluidly connectable with the inlet and has a rotary drum with a filter surface configured for radially inward fluid flow, a second stage filter assembly that is fluidly connectable with the first stage filter and has a plurality of filter discs configured for radially outward fluid flow, and an outlet fluidly connectable with filtrate generated by the second stage disc filter assembly.