Patents Assigned to Lemna Corporation
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Patent number: 6136194Abstract: A wastewater treatment system substantially reduces wastewater treatment time and increases treatment capacity. The system includes at least one completely covered aerobic reactor cell and a completely covered quiescent anaerobic reactor cell. The system can also include a polishing reactor for further treating wastewater after treatment by the anaerobic reactor cell. The covered aerobic reactor cell preferably includes a pair of subcells in which a first cell includes continuous mixing and aeration of the wastewater and the second cell includes only intermittent mixing and aeration of the treated wastewater. The system optionally includes a completely covered anoxic reactor cell for treating wastewater prior to treatment by the completely covered aerobic reactor cell. The anoxic reactor cell receives partially treated wastewater recirculated from the polishing reactor. Growth media can be used in the reactor cells to enhance biological activity.Type: GrantFiled: January 19, 1999Date of Patent: October 24, 2000Assignee: The Lemna CorporationInventors: Steven M. Vogel, Surya R. Pidaparti
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Patent number: 5861095Abstract: A wastewater treatment system substantially reduces wastewater treatment time and increases treatment capacity. The system includes at least one completely covered aerobic reactor cell and a completely covered quiescent anaerobic reactor cell. The system can also include a polishing reactor for further treating wastewater after treatment by the anaerobic reactor cell. The covered aerobic reactor cell preferably includes a pair of subcells in which a first cell includes continuous mixing and aeration of the wastewater and the second cell includes only intermittent mixing and aeration of the treated wastewater. The sytem optionally includes a completely covered anoxic reactor cell for treating wastewater prior to treatment by the completely covered aerobic reactor cell. The anoxic reactor cell receives partially treated wastewater recirculated from the polishing reactor.Type: GrantFiled: April 9, 1997Date of Patent: January 19, 1999Assignee: Lemna CorporationInventors: Steven M. Vogel, Surya R. Pidaparti
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Patent number: 5736047Abstract: A hybrid system and related process for the removal of biological nutrients from wastewater. The system provides an activated sludge system, including both a single-sludge reactor and clarification unit, flowably connected with a final aquaculture pond for final polishing of BOD from the clarified mixed liquor supernatant.Type: GrantFiled: May 4, 1995Date of Patent: April 7, 1998Assignee: Lemna CorporationInventor: Viet H. Ngo
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Patent number: 5534141Abstract: A wastewater treatment system for deployment in a body of water having a floor and a water surface includes an in-pond clarifier extending across the body of water. The in-pond clarifier defines a clarifying chamber and includes an upper portion and a lower portion. The upper portion is suspended above the wastewater surface. The lower portion is maintained adjacent to the floor of the body of water. As a result, the body of water is divided into distinct treatment zones on opposite sides of the clarifying chamber. The in-pond clarifier further includes a plurality of pumps for removing biological solids which settle within the clarifying chamber. Separate pumps are provided for either returning settled solids to the body of water or for wasting settled solids from the body of water.Type: GrantFiled: December 9, 1994Date of Patent: July 9, 1996Assignee: The Lemna CorporationInventors: David W. McAnaney, John R. Dorner
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Patent number: 5421999Abstract: A floating nitrification reactor for use in a treatment pond utilizes a mass of high surface area material which provides sites for bacterial treatment. Floatation devices are attached to the mass of high surface area material in order to float the material at neutral buoyancy while an isolator surrounds the material and isolates the material from the rest of the treatment pond. An aerator, located a distance below the mass of high surface area material, forces air and water through the material at a sufficient speed to allow treatment.Type: GrantFiled: July 25, 1994Date of Patent: June 6, 1995Assignee: The Lemna CorporationInventors: Warren D. Poole, David J. Burton
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Patent number: 5409601Abstract: A floating aquatic plant water treatment system (31) utilizes a serpentine channel (36) defined by dividing walls (34). Floating plants (72) are distributed across the water surface by a floating grid structure (32). The grid structure (32) is preassembled into Z-fold bundles (88) which are towed onto the water and unfolded. The treatment system uses sprayers (62) to control growth conditions. Porous baffles (46) are placed along portions of the channel (36) to provide intimate contact with a larger portion of the water while allowing free flow.Type: GrantFiled: July 6, 1993Date of Patent: April 25, 1995Assignee: The Lemna CorporationInventors: Viet H. Ngo, Warren D. Poole, Sean J. Hancock, Timothy T. France
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Patent number: 5338452Abstract: An anaerobic reaction system for treatment of a continuous flow of wastewater comprises a wastewater inlet, a first anaerobic reactor connected to the inlet, a second anaerobic reactor connected to the inlet and parallel to the first reactor, and a split box between the inlet and the first and second reactor. The split box channels the continuous flow of wastewater to the first reactor and to the second reactor. Effluent empties from the first reactor while wastewater in the second reactor is anaerobically reacted upon and clarified. Alternately, effluent empties from the second reactor while wastewater contained in the first reactor is anaerobically reacted upon and clarified.Type: GrantFiled: January 14, 1993Date of Patent: August 16, 1994Assignee: The Lemna CorporationInventor: Surya R. Pidaparti
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Patent number: 5264127Abstract: A floating aquatic plant water treatment system (31) utilizes a serpentine channel (36) defined by dividing walls (34). Floating plants (72) are distributed across the water surface by a floating grid structure (32). The grid structure (32) is preassembled into Z-fold bundles (88) which are towed onto the water and unfolded. The treatment system uses sprayers (62) to control growth conditions. Porous baffles (46) are placed along portions of the channel (36) to provide intimate contact with a larger portion of the water while allowing free flow.Type: GrantFiled: December 11, 1992Date of Patent: November 23, 1993Assignee: The Lemna CorporationInventors: Viet H. Ngo, Warren D. Poole, Sean J. Hancock, Timothy T. France
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Patent number: 5256281Abstract: A sewage treatment pond has an inlet for introduction of sewage into the pond and an outlet for removal of sewage from the pond. A first baffle extends from the surface of the pond to the bottom of the pond and between the inlet and the outlet. The first baffle has an opening located a first distance from the surface of the pond so that sewage can pass through the opening. A second baffle is located between the inlet and the outlet. The second baffle extends from the surface of the pond to the bottom of the pond. The second baffle has an opening located a second distance from the surface of the pond.Type: GrantFiled: June 20, 1991Date of Patent: October 26, 1993Assignee: The Lemna CorporationInventors: Viet Ngo, Gary L. D'Heilly
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Patent number: 5235797Abstract: Aquatic plants are harvested from a body of water. The aquatic plants are gathered from the surface of the body of water and transported to a collection zone at a collection point on the body of water. The aquatic plants are then moved from the collection zone to an aquatic plant processing station.Type: GrantFiled: February 13, 1992Date of Patent: August 17, 1993Assignee: The Lemna CorporationInventors: Victor V. Sygen, David J. Burton, Lawrence J. DeVore
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Patent number: 5197263Abstract: A duckweed slurry is recovered from a body of water. The duckweed slurry includes duckweed and water from the body of water. The duckweed slurry is transported to a dewatering station. A majority of the water from the duckweed slurry is removed at the dewatering station. Water removed from the duckweed slurry is returned to the body of water.Type: GrantFiled: September 13, 1991Date of Patent: March 30, 1993Assignee: The Lemna CorporationInventors: Brian J. Midtling, Lawrence J. DeVore, Victor V. Sygen
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Patent number: 5180501Abstract: A floating aquatic plant water treatment system (31) utilizes a serpentine channel (36) defined by dividing walls (34). Floating plants (72) are distributed across the water surface by a floating grid structure (32). The grid structure (32) is preassembled into Z-fold bundles (88) which are towed onto the water and unfolded. The treatment system uses sprayers (62) to control growth conditions. Porous baffles (46) are placed along portions of the channel (36) to provide intimate contact with a larger portion of the water while allowing free flow.Type: GrantFiled: June 20, 1991Date of Patent: January 19, 1993Assignee: The Lemna CorporationInventors: Viet H. Ngo, Warren D. Poole, Sean J. Hancock, Timothy T. France
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Patent number: 5161354Abstract: A harvester for harvesting aquatic plants includes a rotatable gate. The rotatable gate subdivides a containment area which is used to hold harvested aquatic plants. The rotatable gate acts to compress harvested aquatic plants and increases harvest capacity.Type: GrantFiled: May 10, 1991Date of Patent: November 10, 1992Assignee: The Lemna CorporationInventors: Victor V. Sygen, David M. Anderson, Lawrence J. DeVore
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Patent number: 5096577Abstract: A floating aquatic plant water treatment system (31) utilizes a serpentine channel (36) defined by dividing walls (34). Floating plants (72) are distributed across the water surface by a floating grid structure (32). The grid structure (32) is preassembled into Z-fold bundles (88) which are towed onto the water and unfolded. The treatment system uses sprayers (62) to control growth conditions. Porous baffles (46) are placed along portions of the channel (36) to provide intimate contact with a larger portion of the water while allowing free flow.Type: GrantFiled: March 17, 1989Date of Patent: March 17, 1992Assignee: The Lemna CorporationInventors: Viet H. Ngo, Warren D. Poole, Sean J. Hancock, Timothy T. France
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Patent number: 4536988Abstract: The present invention relates to a floating containment barrier grid structure (20) for containment of floating aquatic plants (26) in a body of water (30). The barrier grid structure (20) includes a plurality of interconnected square barrier segments (24), the top edge of the barrier segments extending above the surface of the water so as to prohibit substantial wave action. The floating containment barrier grid structure (20) being anchored by cables (38) and stakes (40) in a somewhat tensioned state while floating in the body of water (30). The barrier grid structure (20) being tensioned to enable portions of the barrier grid structure (20) to be submerged beneath the surface of the water by a harvesting machine (28) while harvesting the floating aquatic plants (26).Type: GrantFiled: January 31, 1984Date of Patent: August 27, 1985Assignee: The Lemna CorporationInventor: Delman R. Hogen