Biomass selection and control for continuous flow granular/flocculent activated sludge processes

Patent metadata

Field	Value
Publication number	US-11919787-B2
Application number	US-202117445555-A
Country	US
Kind code	B2
Filing date	Aug 20, 2021
Priority date	Aug 13, 2018
Publication date	Mar 5, 2024
Grant date	Mar 5, 2024

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. A series of biological process zones lead to a secondary clarifier. Mixed liquor sludge, preferably from an aerobic zone, goes through a classifier or separator processing flow from the aerobic zone, to the secondary clarifier. In a sidestream process that can be included a portion of sludge preferably from an aerobic zone goes through a classifier or separator to selectively produce a granular-rich effluent, and the clarifier may also have a separator to further concentrate granular biomass, most of which is cycled back to an initial multi-stage anaerobic process zone. The anaerobic zone is structured and operated to encourage growth of granules in subsequent process zones.

First claim

We claim:

1. A wastewater treatment system for biological treatment of wastewater including organic sewage, the system including a liquid process configuration for removal of at least nitrogen and for concentrating biomass, in a continuous flow process, with the wastewater and activated sludge moving through the liquid process configuration, comprising:
a plurality of process zones, including a first process zone configured to receive the influent wastewater in continuous flow and to mix the influent wastewater with biomass to produce said activated sludge, which includes a first type of sludge and a second, faster settling sludge that settles faster than the first type of sludge,
a biomass separator downstream of the process zones, positioned to receive activated sludge with the first and second types of sludge, the separator being configured and effective to separate out the second type of sludge from the mixed liquor to produce a first effluent with predominantly the first type of sludge and a second effluent enriched in the second type of sludge, and
a dilution line operable to deliver clarified liquid from the liquid process configuration to join the activated sludge entering the separator for dilution of the flow into the separator to enhance separation.

2. The wastewater treatment system of claim 1 , wherein the first type of sludge comprises floc biomass and the second type of sludge comprises granular biomass.

3. The wastewater treatment system of claim 1 , further including a gravity settling clarifier downstream of the separator configured to receive at least some of said first effluent from the separator, the clarifier effective to produce a clarified effluent and the clarifier having a bottom where settled sludge collects and can be discharged, and said stream of clarified liquid comprising clarified effluent from the clarifier.

4. The wastewater treatment system of claim 3 , wherein
bacteria in the first process zone are effective to produce granular biomass as said second type of sludge as well as flocculent biomass as said first type of sludge, the first process zone being anaerobic or anoxic to encourage formation of granular biomass,
the plurality of process zones including at least a second process zone positioned to receive activated sludge in continuous flow from the first process zone, the activated sludge including granular biomass and flocculent biomass,
one of the plurality of process zones being an aerobic zone,
the biomass separator being effective to separate out granular biomass from the activated sludge, so that the separator produces the first effluent as predominantly flocculent biomass and the second effluent enriched in granular biomass, and
a granular recycle line configured to carry a portion of said second effluent from the separator back to the first process zone.

5. An enhanced biological wastewater treatment system including the wastewater treatment system of claim 2 , acting as a mainstream process for removing nitrogen and/or phosphorus, in combination with a sidestream treatment incubator system for generating granular biomass for use in the mainstream process, the sidestream treatment incubator system comprising:
a biological sludge process stream with a succession of incubator process zones, to remove nitrogen and/or phosphorus from activated sludge, configured to receive a continuous influent of solids processing reject water or influent wastewater into the incubator process zones, a first incubator zone of said incubator process zones being an anaerobic or anoxic zone,
an incubator separator configured to receive sludge flow from the incubator process zones, such that sludge flows through the incubator separator, the incubator separator being effective to separate granular sludge from floc sludge such that granular-rich sludge is collected in a bottom area of the incubator separator, and
a recycle flow line configured to carry a majority of the granular-rich sludge in the incubator separator as recycle to the first incubator zone so as to feed the granular biomass with influent soluble bCOD, and a further granular-rich line configured to carry another portion of the granular-rich sludge in the incubator separator to the mainstream process.

Assignees

• Ovivo Inc

Inventors

• Trivedi Hiren
• Vorwaller John
• Beaman Tyson
• Baker Sophia
• Pino-Jelcic Sergio
• Stensel David

Classifications

• C02F1/52 Primary

  by flocculation or precipitation of suspended impurities {(C02F1/463 takes precedence)} · CPC title

• C02F3/02

  Aerobic processes · CPC title

• C02F2001/007

  Processes including a sedimentation step · CPC title

• C02F2301/046

  Recirculation with an external loop · CPC title

• C02F3/302 Primary

  Nitrification and denitrification treatment (C02F3/308 takes precedence) · CPC title