Deep Shaft Technology, Inc.

Other

Noram Engineering and Constructors Ltd.

V.a.i. Ltd.

Noram Engineering and Construction Ltd.

David C Pollock

This application relates to a circular clarifier for separating and removing separable matter, such as suspended solids, from a liquid. The invention may be used, for example, for separating return activated sludge from clarified liquor using a gas flotation process. The clarifier includes a plurality of fluid feed ports for introducing influent into selected treatment cells of the clarifier in a timed sequence, thereby achieving batch flotation of solids or other separable matter in a continuous infeed process. A plurality of spaced-apart, rotating flocculent handling assemblies traverse the treatment cells for sequentially conveying flocculent into spaced-apart, radially extending collection troughs. All of the flocculent handling assemblies may be driven by a single drive means. Each flocculent handling assembly includes a submerged beach and a scraper assembly including a scraper blade which extends upwardly from the beach. The beaches provide a shear plane underneath the surface layer of flocculent. The scraper assembly includes means for lifting the scraper blade in the vicinity of a trough to enable the blade to traverse over the trough and then descend to a position in contact with or proximate to a corresponding beach. Methods of using the clarifier to more efficiently handle return activated sludge or other fragile flocculent are also described. The clarifier may be stand-alone or adapted to retrofit existing circular primary or secondary sedimentation clarifiers.

Circular clarifier apparatus and method

In a vertical shaft bioreactor, improved devices and methods are provided for enhanced secondary and/or tertiary treatment of wastewater, including residential, municipal and industrial wastewater. The devices and methods of the invention are useful for enhanced secondary wastewater treatment, including BOD and TSS removal. Tertiary treatment can alternately or additionally be achieved in the bioreactor with nitrification of ammonia, with nitrification and denitrification, and with nitrification, denitrification, and chemical phosphorus removal. A vertical shaft bioreactor is also provided which achieves thermophilic aerobic digestion and pasteurization of sewage sludges, optionally to produce class A biosolids.

Methods for biological treatment of waste waters

Apparatus for biological treatment of waste waters

Methods and apparatus for biological treatment of waste waters

This application relates to improvements to long vertical shaft bioreactors for the aerobic biological treatment of wastewater and aerobic digestion of biodegradable sludges. The invention comprises a flow control device and method which improves hydraulic flow, inter-zonal mixing and gas transfer in such bioreactors. The flow control device includes a ported upper plate which is mounted in an upflow chamber of the bioreactor and a lower plate located below the upper plate at the juncture between mix and plug flow zones of the bioreactor which are in fluid communication. At least some of the ports in the upper plate are fitted with adjustable valves for regulating the flow of liquor therethrough and hence the size of a hydraulic head loss imposed by the flow control device. Preferably the upper plate is mounted at a location in the upflow chamber upstream from the inlet where influent is discharged into the bioreactor. The flow control device reduces the circulation velocity of the liquor in an upper circulating zone of the bioreactor and also provides a physical barrier substantially restricting inter-zonal mixing between the mix and plug flow zones.

Apparatus and method for controlling liquor circulation flow in long vertical shaft bioreactors

A multi-channel vertical shaft bioreactor having a downcomer; a riser operatively in communication with the downcomer to form a loop; an off-gas head tank; a part of the loop being through the head tank; a de-gassing plate around which effluent liquor is de-gassed to produce a de-gassed liquor and an off-gas receivable by the head tank; oxygen containing gas injection means for injecting gas into the riser; liquid influent injection means to inject influent into the riser; means to extract liquid effluent from the bioreactor; the improvement comprising one or more vertical baffle plates disposed within an upper part of the head tank to define a plurality of off-gas receiving chambers; a plurality of biofilters, a plurality of off-gas conduits in communication with the chambers and the biofilters to operably allow passage of off-gas from the chambers to the biofilters to effect off-gas aeration in the biofilters; and conduit off-gas controls for the treatment of waste water. Each of the multiple gas confinement compartments in the single head tank can operate at different pressures and enable each of the biofilters to be independently back-washed.

Multi-pressure head tank for use with vertical shaft bioreactors

A method of treating municipal or industrial wastewater containing undesired concentrations of ammonium or nitrate ions comprising treating the wastewater under anoxic, denitrifying conditions with denitrifying bacteria to reduce the concentration of nitrate ion and produce nitrogen gas and a denitrified liquor; treating the denitrified liquor in an aerobic vertical shaft bioreactor with an oxygen-containing gas to effect BOD removal by the bioxidation of organic compounds in the denitried liquor and produce carbon dioxide off-gas and a shaft bioreactor effluent liquor; clarifying a first portion of the shaft bioreactor effluent liquor to provide a first clarified liquor and a second portion of the shaft bioreactor effluent liquor to provide a second clarified liquor; treating the first clarified liquor under aerobic, nitrifying conditions with nitrifying bacteria, an oxygen-containing gas and the off-gas to oxidize ammonium ion to nitrate ion and provide a first nitrified liquor; recycling by adding the first nitrified liquor to the wastewater under step (a); treating the second clarified liquor under aerobic, nitrifying conditions with nitrifying bacteria, an oxygen-containing gas to oxidize ammonium ion to nitrate ion and provide a second nitrified liquor; and removing the said nitrified liquor as plant effluent.

Biodegradeable effluent nutrient removal

An improved biomass waste treatment process wherein an aerobic biological reaction takes place in a vertical chamber having a first portion defining a first zone and a second portion defining a second zone below said first zone, said process comprising feeding a first biomass influent having a first biomass concentration to the first zone; feeding a first oxygen-containing gaseous stream to the first zone to effect mixing of the first oxygen-containing gaseous stream with the first biomass influent to effect circulation in unidirectional upward flow by gas lift and bioxidation to provide a first biomass effluent having a second biomass concentration; feeding first biomass effluent in plug flow mode to the second zone; feeding a second oxygen-containing gaseous stream to the second zone to effect mixing of the second oxygen-containing gaseous stream with the first biomass effluent without re-circulation to the first zone to effect bioxidation and provide a second biomass effluent and removing second biomass effluent from the second zone.

Aerobic long vertical shaft bioreactors

An improved apparatus for treating waste mixed liquor comprising a long vertical downcomer chamber; an adjacent long vertical riser chamber; a surface basin; said downcomer chamber and said riser chamber operatively communicating directly with each other at their lower ends and through said basin at their upper ends to form a circulatory loop; means for injecting an oxygen-containing gas in said downcomer and riser chambers at depth; a flotation-sedimentation vessel adjacent said surface basin; a first waste liquor influent conduit opening into said riser chamber at depth and operatively communicating with said vessel to provide a first waste liquor influent from said vessel to said riser chamber; a treated liquor effluent first conduit opening into said riser chamber and operatively in communication with said vessel to provide a treated waste liquor first effluent to said vessel from said riser chamber; the improvement comprising a treated waste liquor effluent second conduit having an inlet opening into said surface basin and operatively in communication with said vessel to provide a treated waste liquor second effluent to said vessel from said surface basin; and flow control and mixing means to operatively provide said treated waste liquor first and second effluents in such intimate mixing of said first and said second effluents as to cause heterogeneous bubble nucleation thereof and produce a nucleated liquor. The apparatus provides for improved flocculation, flotation and settlement of solids.

Growing community of inventors

Calgary, Canada

David C Pollock