Abstract: A dewatering device for removing entrained solids and debris from a liquid stream includes a housing defining a chamber. An auger has a first end positioned outside the chamber and a second end positioned inside the chamber. A compaction zone includes a first tube fixed to the housing. A second tube is slidably mounted on the first tube. A partition is secured to the second tube and has a first longitudinal position in the housing allowing a solids plug to form in the compaction zone and a second longitudinal position in the housing preventing the solids plug from forming in the compaction zone.

Abstract: An apparatus for removing debris from water in a channel includes a bar screen assembly having a plurality of spaced apart, elongated filter bars arranged in a parallel relationship. A continuous conveyor carries a plurality of rakes. Each rake includes a plurality of spaced-apart tines interdigitated with the filter bars as the rake is moved along the filter bars by the conveyor to remove debris from the bar screen assembly. A conveyor belt retaining system includes at least one guide engaging an upstream side of an inner run of the conveyor and a counterweight connected to the at least one guide for biasing the inner run in a downstream direction.

Abstract: A wastewater filter conversion kit for replacing filter elements connected to a shaft includes first and second conveyor segments. Each conveyor segment includes a perforated panel. At least one first tube is secured to a first end of the panel. At least one second tube is secured to a second end of the panel. The least one first tube on the first conveyor segment and the at least one second tube on the second conveyor segment are aligned along a common centerline for receiving the shaft to replace the filter elements on the shaft.

Abstract: The present disclosure provides improved methods for conducting a wash cycle in a filtration unit. The methods may be used alone or in combination with one another to achieve the improvements described herein. Filtration units adapted for carrying out the novel methods are also provided. Through the use of the methods and filtration units described, significant economic benefits are obtained without a significant increase in the costs of the filtration unit or in the costs of operation of the filtration unit.

Abstract: A pumped or gravity flow rotating drum screen removes unwanted solids from a flowing fluid. The drum screen may comprise: a housing having a fluid inlet end, a solid discharge end and an area between the two ends, the fluid inlet permitting a flow of influent containing unwanted solids into a hollow portion of a drum screen positioned lengthwise in the area between the two ends of the housing, the screen comprising a filter medium that retains at least a portion of the unwanted solids within the hollow portion of the drum screen and which produces a liquid effluent that is discharged from an outer surface of the drum screen, the retained solids being removable via the solid discharge end; a drive assembly configured to rotate the drum screen about an axis running the length of the drum screen; and one or more stabilization pad assemblies in contact with one or more rings circumscribing the outer surface of the drum screen at one or more locations.

Abstract: A method and an apparatus for treating a liquid containing impurities may include a filtering chamber configured to permit granular media to interact with liquid containing impurities, thereby removing impurities from the liquid to produce filtrate; a filtrate section for receiving the filtrate; a gas supplying system for delivering gas to the granular media in the filtering chamber for transport of a portion of the granular media to a granular media washer; a reject section in fluid communication with the granular media washer for receiving a reject mixture comprising liquid and impurities from the granular media washer; and a control unit that is configured to determine whether the portion of the granular media is being transported properly based on an amount of reject mixture in the reject section.

Abstract: The disclosed method and apparatus separates solid impurities from a fluid containing solid impurities. The method and apparatus allow the introduction of influent comprising a fluid containing solid impurities into a plurality of channels and allowing at least a portion of the solid impurities initially present in the influent to settle on upward-facing surfaces of a plurality of plates forming the channels or slide down the upward-facing surfaces, while permitting fluid, which has been depleted of at least a portion of solid impurities, to flow upward toward the top edges of the plurality of plates. The influent is introduced into the plurality of channels in a manner that inhibits a disrupting or disturbing of the solid impurities, which have separated from the influent.

Abstract: A pumped or gravity flow rotating drum screen removes unwanted solids from a flowing fluid. The drum screen may comprise: a housing having a fluid inlet end, a solid discharge end and an area between the two ends, the fluid inlet permitting a flow of influent containing unwanted solids into a hollow portion of a drum screen positioned lengthwise in the area between the two ends of the housing, the screen comprising a filter medium that retains at least a portion of the unwanted solids within the hollow portion of the drum screen and which produces a liquid effluent that is discharged from an outer surface of the drum screen, the retained solids being removable via the solid discharge end; a drive assembly configured to rotate the drum screen about an axis running the length of the drum screen; and one or more stabilization pad assemblies in contact with one or more rings circumscribing the outer surface of the drum screen at one or more locations.

Abstract: The disclosed method and apparatus separates solid impurities from a fluid containing solid impurities. The method and apparatus allow the introduction of influent comprising a fluid containing solid impurities into a plurality of channels and allowing at least a portion of the solid impurities initially present in the influent to settle on upward-facing surfaces of a plurality of plates forming the channels or slide down the upward-facing surfaces, while permitting fluid, which has been depleted of at least a portion of solid impurities, to flow upward toward the top edges of the plurality of plates. The influent is introduced into the plurality of channels in a manner that inhibits a disrupting or disturbing of the solid impurities, which have separated from the influent.

Abstract: A pumped or gravity flow rotating drum screen removes unwanted solids from a flowing fluid. The drum screen may comprise: a housing having a fluid inlet end, a solid discharge end and an area between the two ends, the fluid inlet permitting a flow of influent containing unwanted solids into a hollow portion of a drum screen positioned lengthwise in the area between the two ends of the housing, the screen comprising a filter medium that retains at least a portion of the unwanted solids within the hollow portion of the drum screen and which produces a liquid effluent that is discharged from an outer surface of the drum screen, the retained solids being removable via the solid discharge end; a drive assembly configured to rotate the drum screen about an axis running the length of the drum screen; and one or more stabilization pad assemblies in contact with one or more rings circumscribing the outer surface of the drum screen at one or more locations.

Abstract: A dual-level control system for operating a wastewater treatment apparatus may include at least a primary level of control including a measurement of a process control variable to arrive at a dissolved oxygen (DO) set point and a primary mode of operating parameters including primary aeration chain timer and primary aeration chain grouping designed to achieve the DO set point when the DO set point falls within a predetermined range of values; and at least a secondary level of control to arrive at a secondary mode of operating parameters including secondary aeration chain timer and secondary aeration chain grouping designed to achieve a desired concentration of effluent total nitrogen when the DO set point either falls to or below a minimum value or rises to or above a maximum value. The process control variable may be, for example, an effluent concentration of NH3, NO3, alkalinity, ORP, or a combination thereof.

Abstract: The disclosed method and apparatus separates solid impurities from a fluid containing solid impurities. The method and apparatus allow the introduction of influent comprising a fluid containing solid impurities into a plurality of channels and allowing at least a portion of the solid impurities initially present in the influent to settle on upward-facing surfaces of a plurality of plates forming the channels or slide down the upward-facing surfaces, while permitting fluid, which has been depleted of at least a portion of solid impurities, to flow upward toward the top edges of the plurality of plates. The influent is introduced into the plurality of channels in a manner that inhibits a disrupting or disturbing of the solid impurities, which have separated from the influent.

Abstract: The disclosed method and apparatus separates solid impurities from a fluid containing solid impurities. The method and apparatus allow the introduction of influent comprising a fluid containing solid impurities into a plurality of channels and allowing at least a portion of the solid impurities initially present in the influent to settle on upward-facing surfaces of a plurality of plates forming the channels or slide down the upward-facing surfaces, while permitting fluid, which has been depleted of at least a portion of solid impurities, to flow upward toward the top edges of the plurality of plates. The influent is introduced into the plurality of channels in a manner that inhibits a disrupting or disturbing of the solid impurities, which have separated from the influent.

Abstract: A method and an apparatus for treating a liquid containing impurities may include a filtering chamber configured to permit granular media to interact with liquid containing impurities, thereby removing impurities from the liquid to produce filtrate; a filtrate section for receiving the filtrate; a gas supplying system for delivering gas to the granular media in the filtering chamber for transport of a portion of the granular media to a granular media washer; a reject section in fluid communication with the granular media washer for receiving a reject mixture comprising liquid and impurities from the granular media washer; and a control unit that is configured to determine whether the portion of the granular media is being transported properly based on an amount of reject mixture in the reject section.

Abstract: An apparatus for treating a liquid containing impurities may comprise: a filtering chamber for receiving liquid containing impurities, the filtering chamber containing granular media and configured to permit the granular media to interact with the liquid containing impurities, thereby removing impurities from the liquid to produce filtrate; a filtrate section in communication with the filtering chamber for receiving the filtrate, the filtrate section being in communication with a first outlet for outflow of the filtrate; a gas supplying system for delivering gas to the granular media in the filtering chamber for transport of a portion of the granular media to a granular media washer; and a reject section in communication with the granular media washer for receiving a reject mixture comprising liquid and impurities from the granular media washer. The reject section may be in communication with a second outlet for outflow of a portion of the reject mixture.

Abstract: A method and a computer program product perform a backwash process, which facilitates a reduction in a reject rate associated with a water treatment tank. If a backwash process is needed, an upper burst solenoid is operated to start an airlift flow in a first airlift path at a first position and at a first point in time, at a bottom portion of the water treatment tank, and a lower burst solenoid is operated to start an airlift flow in a second airlift path at a second position and at a second point in time. The second position is below the first position and the second point in time is after the first point in time. The airlift flow in the first and second airlift paths enables suitable water flow within the water treatment tank.

Abstract: An apparatus for treating a liquid containing impurities may comprise: a filtering chamber for receiving liquid containing impurities, the filtering chamber containing granular media and configured to permit the granular media to interact with the liquid containing impurities, thereby removing impurities from the liquid to produce filtrate; a filtrate section in communication with the filtering chamber for receiving the filtrate, the filtrate section being in communication with a first outlet for outflow of the filtrate; a gas supplying system for delivering gas to the granular media in the filtering chamber for transport of a portion of the granular media to a granular media washer; and a reject section in communication with the granular media washer for receiving a reject mixture comprising liquid and impurities from the granular media washer. The reject section may be in communication with a second outlet for outflow of a portion of the reject mixture.

Abstract: A method and an apparatus for treating a liquid containing impurities may include a filtering chamber configured to permit granular media to interact with liquid containing impurities, thereby removing impurities from the liquid to produce filtrate; a filtrate section for receiving the filtrate; a gas supplying system for delivering gas to the granular media in the filtering chamber for transport of a portion of the granular media to a granular media washer; a reject section in fluid communication with the granular media washer for receiving a reject mixture comprising liquid and impurities from the granular media washer; and a control unit that is configured to determine whether the portion of the granular media is being transported properly based on an amount of reject mixture in the reject section.

Abstract: A sand washing apparatus may be used for separating organic material from a mixture comprising sand and organic material. The apparatus may comprise: a wash chamber for accepting a mixture comprising sand and organic material, the chamber including a lower portion; and an agitator comprising a screw having two or more flights extending into the lower portion. A method for recovering sand from a mixture comprising sand and organic material may comprise the steps of: introducing a mixture comprising sand and organic material into a water-filled chamber having a net flow of water in an upwardly direction; allowing organic material from the mixture to ascend in a net upwardly direction and allowing sand from the mixture to descend in a net downwardly direction; subjecting at least a portion of the descending sand to a turbulence; and recovering sand that has descended past the turbulence.

Abstract: The disclosed apparatus aeration assembly is used for submersion in and aeration of wastewater contained in a receptacle. The assembly may comprise a non-floating planar grid supporting a plurality of gas diffuser panels. The supporting grid may have at least two ends; one or more gas inlets affixed to one of the at least two ends for supplying gas to the plurality of gas diffuser panels; and one or more lift lines of a predetermined length affixed to each of the at least two ends with all lift lines meeting at a juncture. The juncture may be positioned above a plane of the supporting grid so that the predetermined length of a line affixed to one of the at least two ends is unequal to the predetermined length of a line affixed to another of the at least two ends.