Patents by Inventor H. David Stensel

H. David Stensel has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10781125
    Abstract: A continuous flow granular/flocculent sludge wastewater process selects for granule biomass capable of nitrogen and phosphorus removal and controls granule size and concentration of granular and flocculent sludge for optimal nutrient, organic, and solids removal in a smaller footprint. It includes anaerobic, anoxic, and aerobic process zones, a high soluble biodegradable COD loaded first reactor in anaerobic or anoxic zones, a granular sludge classifier with recycle of underflow granular sludge to the first reactor, a secondary clarifier to settle flocculent sludge and particulates and recycle of flocculent sludge from the secondary clarifier underflow to an aerobic process zone. Wasting of sludge from the two separate recycle lines controls the bioprocess flocculent and granular sludge concentrations and SRTs. Bypass around and recycle flow to the classifier to maintain desired flow under various influent flow conditions aid control of granule size.
    Type: Grant
    Filed: August 9, 2019
    Date of Patent: September 22, 2020
    Assignee: Ovivo Inc.
    Inventors: H. David Stensel, Hiren Trivedi, John Vorwaller, Tyson Beaman
  • Publication number: 20200048131
    Abstract: A continuous flow granular/flocculent sludge wastewater process selects for granule biomass capable of nitrogen and phosphorus removal and controls granule size and concentration of granular and flocculent sludge for optimal nutrient, organic, and solids removal in a smaller footprint. It includes anaerobic, anoxic, and aerobic process zones, a high soluble biodegradable COD loaded first reactor in anaerobic or anoxic zones, a granular sludge classifier with recycle of underflow granular sludge to the first reactor, a secondary clarifier to settle flocculent sludge and particulates and recycle of flocculent sludge from the secondary clarifier underflow to an aerobic process zone. Wasting of sludge from the two separate recycle lines controls the bioprocess flocculent and granular sludge concentrations and SRTs. Bypass around and recycle flow to the classifier to maintain desired flow under various influent flow conditions aid control of granule size.
    Type: Application
    Filed: August 9, 2019
    Publication date: February 13, 2020
    Inventors: H. David Stensel, Hiren Trivedi, John Vorwaller, Tyson Beaman
  • Patent number: 5985649
    Abstract: A method and apparatus for removing select gas contaminants is disclosed. The apparatus is a bioreactor having a chamber for containing liquid and a liquid positioned therein, the liquid forming a column having a top and a bottom surface defining a height. The bioreactor further has a gas dispersal unit positioned in the column and a selected biomass suspended in the liquid, where the biomass is selected to metabolize the gas contaminant requiring degradation. The method includes feeding a select gas contaminant having a low Henry's coefficient into the gas dispersal unit to produce a stream of bubbles containing the gas contaminants, where the gas contaminant is a food source for said biomass, and allowing the stream of bubbles to sparge through and exit the top of said column.
    Type: Grant
    Filed: April 28, 1997
    Date of Patent: November 16, 1999
    Assignee: H. David Stensel
    Inventors: H. David Stensel, Angela R. Bielefeldt
  • Patent number: 5874291
    Abstract: This invention pertains to substantially purified cultures of a gram-negative, aerobic, filamentous bacterium with cells ranging in length from 20-200 .mu.m, that accumulates intracellular poly-.beta.-hydroxybutyrate in intracellular granules, and that degrades chlorinated aliphatic compounds such as trichloroethylene and dichloroethylene, as well as phenol and other substituted benzenes. The invention includes the representative strain A-1, which has been deposited at the American Type Culture Collection under the accession number 55581. Also included are methods for using the new bacterium for bioremediation of contaminated environmental sites.
    Type: Grant
    Filed: April 30, 1996
    Date of Patent: February 23, 1999
    Assignee: University of Washington
    Inventors: Angela R. Bielefeldt, H. David Stensel, Stuart E. Strand, Russell P. Herwig
  • Patent number: 5582734
    Abstract: A method for treating municipal wastewater in an oxidation ditch activated sludge system by automated determination of the nitrogen depletion inflection point, which enables anoxic cycles to be utilized to achieve improved settling of the activated sludge by providing selective pressure against the growth of filamentous bacteria, by providing improved total nitrogen removal, by providing energy savings and by providing recovery of alkalinity.
    Type: Grant
    Filed: September 14, 1993
    Date of Patent: December 10, 1996
    Assignee: H. David Stensel
    Inventors: Thomas E. Coleman, W. Brent Denham, Darrel S. Fleischman, H. David Stensel
  • Patent number: 4303516
    Abstract: There is provided a system for treating wastewater having a tank and a partition mounted in the tank to define an endless circuitous channel. An aerator and impeller is mounted in the tank to cause the liquid to flow through the channel. A clarifier is disposed in the channel and has a liquid outlet in its upper portion.
    Type: Grant
    Filed: October 14, 1980
    Date of Patent: December 1, 1981
    Assignee: Envirotech Corporation
    Inventors: H. David Stensel, Peter Maier, Mark G. Biesinger, David R. Refling, Ronald P. Klepper, John V. Maxham