Patents Assigned to CH2M Hill Canada Limited
  • Publication number: 20080047896
    Abstract: This disclosure describes wastewater treatment systems and methods of treating wastewater. In one exemplary method, a wastewater is split into first and second wastewater fractions. The first fraction is delivered to a membrane bioreactor, which may produce an effluent with a low pollutant concentration, and the second fraction is delivered to a biological wastewater treatment system, which may yield a higher pollution concentration yet have a shorter solids retention time. Some implementations of the invention can routinely meet or even exceed pollution discharge standards quite economically during normal operation, yet retain significant flexibility for handling seasonal or sudden variations in the flow rate of wastewater into the system. In select adaptations, waste activated sludge containing heterotrophs, autotrophs, and (optionally) polyphosphate accumulating organisms is delivered from the membrane bioreactor to the biological wastewater treatment system.
    Type: Application
    Filed: September 28, 2007
    Publication date: February 28, 2008
    Applicants: CH2M HILL, Inc., CH2M HILL Canada Limited
    Inventors: Bruce Johnson, Glen Daigger, George Crawford
  • Patent number: 7279102
    Abstract: This disclosure describes wastewater treatment systems and methods of treating wastewater. In one exemplary method, a wastewater is split into first and second wastewater fractions. The first fraction is delivered to a membrane bioreactor, which may produce an effluent with a low pollutant concentration, and the second fraction is delivered to a biological wastewater treatment system, which may yield a higher pollution concentration yet have a shorter solids retention time. Some implementations of the invention can routinely meet or even exceed pollution discharge standards quite economically during normal operation, yet retain significant flexibility for handling seasonal or sudden variations in the flow rate of wastewater into the system. In select adaptations, waste activated sludge containing heterotrophs, autotrophs, and (optionally) polyphosphate accumulating organisms is delivered from the membrane bioreactor to the biological wastewater treatment system.
    Type: Grant
    Filed: November 30, 2004
    Date of Patent: October 9, 2007
    Assignees: CH2M Hill, Inc., CH2M Hill Canada Limited
    Inventors: Bruce R. Johnson, Glen T. Daigger, George V. Crawford
  • Publication number: 20060113244
    Abstract: This disclosure describes wastewater treatment systems and methods of treating wastewater. In one exemplary method, a wastewater is split into first and second wastewater fractions. The first fraction is delivered to a membrane bioreactor, which may produce an effluent with a low pollutant concentration, and the second fraction is delivered to a biological wastewater treatment system, which may yield a higher pollution concentration yet have a shorter solids retention time. Some implementations of the invention can routinely meet or even exceed pollution discharge standards quite economically during normal operation, yet retain significant flexibility for handling seasonal or sudden variations in the flow rate of wastewater into the system.
    Type: Application
    Filed: November 30, 2004
    Publication date: June 1, 2006
    Applicants: CH2M HILL Canada Limited, CH2M HILL, Inc.
    Inventors: Bruce Johnson, Glen Daigger, George Crawford