Patents Assigned to D.C. Water & Sewer Authority
  • Patent number: 10464832
    Abstract: An apparatus and method for selecting, retaining or bioaugmenting solids in an activated sludge process for improving wastewater treatment using a screen device. If desired, the screen device may include a drum, and the rotating speed of the drum may be used to control the solids retained. Effluent including waste biomass may exit the screen device. No other discharge unit from the screen device may be required.
    Type: Grant
    Filed: April 4, 2016
    Date of Patent: November 5, 2019
    Assignee: D.C. Water & Sewer Authority
    Inventors: Sudhir N. Murthy, Bernhard Wett, Haydee Declippeleir
  • Patent number: 10112856
    Abstract: A method and a system for selecting and retaining solids with superior settling characteristics, the method comprising feeding wastewater to an input of a processor that carries out a treatment process on the wastewater, outputting processed wastewater at an output of the processor, feeding the processed wastewater to an input of a gravimetric selector that selects solids with superior settling characteristics, and outputting a recycle stream at a first output of the gravimetric selector back to the processor.
    Type: Grant
    Filed: January 21, 2016
    Date of Patent: October 30, 2018
    Assignees: Hampton Roads Sanitation District, D.C. Water & Sewer Authority
    Inventors: Charles Bott, Maureen O'Shaughnessy, Bernhard Wett, Sudhir Murthy
  • Patent number: 10005683
    Abstract: One or more reactor and one or more control methods are used for nitrogen removal in wastewater treatment to achieve measured control of maintaining high ammonia oxidizing bacteria (AOB) oxidation rates while achieving nitrite oxidizing bacteria (NOB) out-selection, using various control strategies, including: 1) ammonia and the use of ammonia setpoints; 2) operational DO and the use of DO setpoints; 3) bioaugmentation of anammox and lighter flocculant AOB fraction; and 4) implementation of transient anoxia in several reactor configurations and conditions for removal of oxidized nitrogen using anammox or heterotrophic organisms.
    Type: Grant
    Filed: May 16, 2016
    Date of Patent: June 26, 2018
    Assignees: D.C. Water & Sewer Authority, Hampton Roads Sanitation District
    Inventors: Bernhard Wett, Ahmed Omari, Pusker Regmi, Mark Miller, Charles B. Bott, Sudhir N. Murthy
  • Patent number: 9802847
    Abstract: An apparatus and method for selecting and retaining solids in an activated sludge process for the improving wastewater treatment using screens. The screens can be used to separate and retain solids based on size or compressibility. The screens are used to separate and select for slow growing organisms, faster settling organisms, or materials added to absorb, treat or remove constituents in the activated sludge process.
    Type: Grant
    Filed: September 23, 2013
    Date of Patent: October 31, 2017
    Assignee: D.C. Water & Sewer Authority
    Inventors: Sudhir N. Murthy, Eugenio Giraldo, Norman D. Dockett, Walter F. Bailey
  • Patent number: 9738502
    Abstract: This disclosure relates to a tool, system of tools, or method of utilizing tools to quickly, safely, ergonomically and effectively lift any number of objects including but not limited to manhole covers and car tires. The user is aided by the tool containing any number of picks that may be directionally adjusted, manually or automatically, latches to connect the tool to attachments (such as tripods, power lifting belts, vehicles, and other tools), additional support handle bars located at or about the center of gravity which may be adjusted from one location to another to guide the body into a lifting posture to reduce back strain and accident potential, pre-molded or moldable sections on the tool or its handlebars to aid the user in gripping the tool, a gyroscope and other features for making the jobs of utility workers and service workers safer, more efficient, and easier.
    Type: Grant
    Filed: January 27, 2016
    Date of Patent: August 22, 2017
    Assignee: D.C. Water & Sewer Authority
    Inventors: Wade L. Brooks, James Lowell Ramsey Clarke
  • Patent number: 9469558
    Abstract: A reactor and control method thereof to maximize nitrogen removal and minimize aeration requirement through control of transient anoxia and aerobic SRT, repression of NOB, and control of dynamic DO concentrations or aeration interval by keeping the reactor NH4 and NOx concentrations approximately equal has been proposed. Controls described in this invention maximizes the potential for TIN removal through nitrification, limited nitritation, nitritation, denitrification, limited denitritation, denitritation making use of 1) real time measurement of ammonia, nitrite, nitrate, 2) operational DO and the proper use of DO setpoints, and 3) proper implementation of transient anoxia within a wide range of reactor configurations and operating conditions.
    Type: Grant
    Filed: October 1, 2013
    Date of Patent: October 18, 2016
    Assignees: D.C. Water & Sewer Authority, Hampton Roads Sanitation District
    Inventors: Pusker Regmi, Mark Miller, Charles B. Bott
  • Patent number: 9352990
    Abstract: A reactor and control method for maximizing nitrogen removal and minimizing aeration requirements through control of transient anoxia and aerobic SRT, repression of NOB, and control of dynamic DO concentrations or aeration interval by keeping the reactor NH4 and NOx concentrations approximately equal. Controls are provided for maximizing the potential for TIN removal through nitrification, limited nitritation, nitritation, denitrification, limited denitritation, denitritation making use of 1) real time measurement of ammonia, nitrite, nitrate, 2) operational DO and the proper use of DO setpoints, and 3) proper implementation of transient anoxia within a wide range of reactor configurations and operating conditions.
    Type: Grant
    Filed: March 14, 2014
    Date of Patent: May 31, 2016
    Assignees: D.C. Water & Sewer Authority, Hampton Roads Sanitation District
    Inventors: Pusker Regmi, Mark Miller, Sudhir N. Murthy, Charles B. Bott
  • Patent number: 9346694
    Abstract: One or more reactor and one or more control methods are used for nitrogen removal in wastewater treatment to achieve measured control of maintaining high ammonia oxidizing bacteria (AOB) oxidation rates while achieving nitrite oxidizing bacteria (NOB) out-selection, using various control strategies, including: 1) ammonia and the use of ammonia setpoints; 2) operational DO and the use of DO setpoints; 3) bioaugmentation of anammox and lighter flocculant AOB fraction; and 4) implementation of transient anoxia in several reactor configurations and conditions for removal of oxidized nitrogen using anammox or heterotrophic organisms.
    Type: Grant
    Filed: September 13, 2013
    Date of Patent: May 24, 2016
    Assignees: D.C. Water & Sewer Authority, Hampton Roads Sanitation District
    Inventors: Bernhard Wett, Ahmed Omari, Pusker Regmi, Mark Miller, Charles B. Bott, Sudhir N. Murthy
  • Publication number: 20160137537
    Abstract: A method and a system for selecting and retaining solids with superior settling characteristics, the method comprising feeding wastewater to an input of a processor that carries out a treatment process on the wastewater, outputting processed wastewater at an output of the processor, feeding the processed wastewater to an input of a gravimetric selector that selects solids with superior settling characteristics, and outputting a recycle stream at a first output of the gravimetric selector back to the processor.
    Type: Application
    Filed: January 21, 2016
    Publication date: May 19, 2016
    Applicants: Hampton Roads Sanitation District, D.C. Water & Sewer Authority
    Inventors: Charles Bott, Maureen O'Shaughnessy, Bernhard Wett, Sudhir Murthy
  • Patent number: 9340439
    Abstract: A reactor and control method thereof for nitrogen removal in wastewater treatment achieves a measured control of maintaining high ammonia oxidizing bacteria (AOB) oxidation rates while achieving nitrite oxidizing bacteria (NOB) repression, using various control strategies, including: 1) ammonia and the use of ammonia setpoints, 2) operational DO and the proper use of DO setpoints, 3) bioaugmentation of a lighter flocculant AOB fraction, and 4) proper implementation of transient anoxia within a wide range of reactor configurations and operating conditions.
    Type: Grant
    Filed: September 13, 2013
    Date of Patent: May 17, 2016
    Assignees: D.C. Water & Sewer Authority, Hampton Roads Sanitation District
    Inventors: Bernhard Wett, Ahmed Omari, Pusker Regmi, Mark Miller, Charles B. Bott, Sudhir N. Murthy
  • Patent number: 9242882
    Abstract: A method and a system for selecting and retaining solids with superior settling characteristics, the method comprising feeding wastewater to an input of a processor that carries out a treatment process on the wastewater, outputting processed wastewater at an output of the processor, feeding the processed wastewater to an input of a gravimetric selector that selects solids with superior settling characteristics, and outputting a recycle stream at a first output of the gravimetric selector back to the processor.
    Type: Grant
    Filed: November 27, 2013
    Date of Patent: January 26, 2016
    Assignees: Hampton Roads Sanitation District, D.C. Water & Sewer Authority
    Inventors: Geert Nyhuis, Maureen O'Shaughnessy, Bernhard Wett, Charles Bott, Sudhir Murthy
  • Publication number: 20150376043
    Abstract: A method and an apparatus for biological wastewater treatment that includes a biological selector and a physical selector. The apparatus comprises an internal biological reactor where wastewater and recycled biomass are combined to provide a high substrate and high electron acceptor gradient for generating morphological biomass features that favor granule formation over floc and filament formation, and an external gravimetric or external screen selector operating on the biomass waste stream for collecting and retaining densified biomass aggregates including dense granule selection and for wasting lighter filaments and flocs. In the method and apparatus, particles may be added to provide cores to promote the formation of aggregates encapsulating the seeded particles. The particles may be added as various materials, for example, in the bioreactor, to initiate or seed the formation of a granule, that could then be separated by or integrated with either the external gravimetric or external screen selector.
    Type: Application
    Filed: June 30, 2015
    Publication date: December 31, 2015
    Applicants: D.C. Water & Sewer Authority, Hampton Roads Sanitation District
    Inventors: Bernhard Wett, Charles Bott, Sudhir Murthy, Haydee De Clippeleir
  • Publication number: 20140263041
    Abstract: A reactor and control method for maximizing nitrogen removal and minimizing aeration requirements through control of transient anoxia and aerobic SRT, repression of NOB, and control of dynamic DO concentrations or aeration interval by keeping the reactor NH4 and NOx concentrations approximately equal. Controls are provided for maximizing the potential for TIN removal through nitrification, limited nitritation, nitritation, denitrification, limited denitritation, denitritation making use of 1) real time measurement of ammonia, nitrite, nitrate, 2) operational DO and the proper use of DO setpoints, and 3) proper implementation of transient anoxia within a wide range of reactor configurations and operating conditions.
    Type: Application
    Filed: March 14, 2014
    Publication date: September 18, 2014
    Applicants: Hampton Roads Sanitation District, D.C. Water & Sewer Authority
    Inventors: Pusker Regmi, Mark Miller, Sudhir N. Murthy, Charles B. Bott
  • Publication number: 20140144836
    Abstract: A method and a system for selecting and retaining solids with superior settling characteristics, the method comprising feeding wastewater to an input of a processor that carries out a treatment process on the wastewater, outputting processed wastewater at an output of the processor, feeding the processed wastewater to an input of a gravimetric selector that selects solids with superior settling characteristics, and outputting a recycle stream at a first output of the gravimetric selector back to the processor.
    Type: Application
    Filed: November 27, 2013
    Publication date: May 29, 2014
    Applicants: D.C. Water & Sewer Authority, Hampton Roads Sanitation District
    Inventors: Geert Nyhuis, Maureen O'Shaughnessy, Bernhard Wett, Charles Bott, Sudhir Murthy
  • Publication number: 20140131273
    Abstract: An apparatus and method for selecting and retaining solids in an activated sludge process for the improving wastewater treatment using screens. The screens can be used to separate and retain solids based on size or compressibility. The screens are used to separate and select for slow growing organisms, faster settling organisms, or materials added to absorb, treat or remove constituents in the activated sludge process.
    Type: Application
    Filed: September 23, 2013
    Publication date: May 15, 2014
    Applicant: D.C. Water & Sewer Authority
    Inventors: Sudhir N. Murthy, Eugenio Giraldo, Norman D. Dockett, Walter F. Bailey
  • Publication number: 20140091035
    Abstract: A reactor and control method thereof to maximize nitrogen removal and minimize aeration requirement through control of transient anoxia and aerobic SRT, repression of NOB, and control of dynamic DO concentrations or aeration interval by keeping the reactor NH4 and NOx concentrations approximately equal has been proposed. Controls described in this invention maximizes the potential for TIN removal through nitrification, limited nitritation, nitritation, denitrification, limited denitritation, denitritation making use of 1) real time measurement of ammonia, nitrite, nitrate, 2) operational DO and the proper use of DO setpoints, and 3) proper implementation of transient anoxia within a wide range of reactor configurations and operating conditions.
    Type: Application
    Filed: October 1, 2013
    Publication date: April 3, 2014
    Applicants: Hampton Roads Sanitation District, D.C. Water & Sewer Authority
    Inventors: Pusker Regmi, Mark Miller, Charles B. Bott
  • Publication number: 20140083936
    Abstract: An apparatus and method for selecting, retaining or bioaugmenting solids in an activated sludge process for improving wastewater treatment using screens. The screens can be used to separate and retain solids based on size, compressibility or shear resistance. The screens are used to separate and select slow growing organisms, faster settling organisms, or materials added to absorb, treat or remove constituents in the activated sludge process. A swapping screen arrangement provides another means of selecting various particles. The exposed shear rate or time, particle compression, or SRTs can be adjusted manually and/or automatically in response to detected readings from an instrument such as a spectrophotometer or other optical approaches to optimize selection of organisms.
    Type: Application
    Filed: September 20, 2013
    Publication date: March 27, 2014
    Applicant: D.C. Water & Sewer Authority
    Inventors: Sudhir N. Murthy, Eugenio Giraldo, Norman D. Dockett, Haydee De Clippeleir, Bernhard Wett, Walter F. Bailey, JR.
  • Publication number: 20140069864
    Abstract: One or more reactor and one or more control methods are used for nitrogen removal in wastewater treatment to achieve measured control of maintaining high ammonia oxidizing bacteria (AOB) oxidation rates while achieving nitrite oxidizing bacteria (NOB) out-selection, using various control strategies, including: 1) ammonia and the use of ammonia setpoints; 2) operational DO and the use of DO setpoints; 3) bioaugmentation of anammox and lighter flocculant AOB fraction; and 4) implementation of transient anoxia in several reactor configurations and conditions for removal of oxidized nitrogen using anammox or heterotrophic organisms.
    Type: Application
    Filed: September 13, 2013
    Publication date: March 13, 2014
    Applicants: Hampton Roads Sanitation District, D.C. Water & Sewer Authority
    Inventors: Bernhard Wett, Ahmed Omari, Pusker Regmi, Mark Miller, Charles B. Bott, Sudhir N. Murthy
  • Publication number: 20140069863
    Abstract: A reactor and control method thereof for nitrogen removal in wastewater treatment achieves a measured control of maintaining high ammonia oxidizing bacteria (AOB) oxidation rates while achieving nitrite oxidizing bacteria (NOB) repression, using various control strategies, including: 1) ammonia and the use of ammonia setpoints, 2) operational DO and the proper use of DO setpoints, 3) bioaugmentation of a lighter flocculant AOB fraction, and 4) proper implementation of transient anoxia within a wide range of reactor configurations and operating conditions.
    Type: Application
    Filed: September 13, 2013
    Publication date: March 13, 2014
    Applicants: Hampton Roads Sanitation District, D.C. Water & Sewer Authority
    Inventors: Bernhard Wett, Ahmed Omari, Pusker Regmi, Mark Miller, Charles B. Bott, Sudhir N. Murthy
  • Patent number: 7833415
    Abstract: An improved process for sludge treatment includes anaerobic digestion followed by post-mesophilic aerobic and/or anoxic digestion. The first anaerobic step may be performed under either mesophilic or thermophilic conditions. The subsequent aerobic/anoxic digestion may be performed using either simultaneous, sequential or pulsed aerobic and anoxic conditions. An apparatus for performing the improved sludge treatment may be one digester for performing the anaerobic followed by aerobic/anoxic digestion. Alternatively, the system for performing the improved sludge treatment techniques may be at least two digest reactors.
    Type: Grant
    Filed: October 25, 2006
    Date of Patent: November 16, 2010
    Assignee: D.C. Water & Sewer Authority
    Inventors: Sudhir N. Murthy, John T. Novak, Walter F. Bailey, Jr., Glen T. Daigger, Perry Schafer, Christopher Peot