Abstract:
An apparatus for aerobic biological treatment of waste water is described, in which a great number of carrier members having a large surface area to which microorganisms adhere are movably set in a cylindrical reactor within a given range of height, and the carrier is horizontally moved substantially continuously so that a part of the carrier is cleaned with cleaning air. The partial cleaning system eliminates the disadvantages associated with intermittent cleaning of the whole carrier.
Abstract:
A large area sparger has a gas-permeable diffuser bonded to a gas-impermeable underlying element so that inflowing gas is distributed throughout a gap between the sparger and the underlying element. Bonding regions interconnect the diffuser and the underlying element around the sparger perimeter and throughout a gap region within the perimeter in a pattern that keeps the diffuser flat during operation and allows gas to flow around the bonding regions to reach all of the unbonded area of the diffuser. By giving the diffuser a liquid interface surface with a high surface energy, the gas passing through a finely porous diffuser departs from the diffuser interface surface and enters the liquid as very fine bubbles having a large area of contact with the liquid.
Abstract:
A wastewater treatment system and method for substantially reducing or eliminating total suspended solids (TSS), biological organic discharge or biochemical oxygen demand (BOD), and fats, oils and greases (FOG) contaminants. The system includes at least one mixing chamber for mixing wastewater with at least one dewatering agent or chemical and air to form an aerated mixture and at least one tank having a plurality of compartments for facilitating flotation, settling and removal of contaminants from the aerated mixture as it flows through the tank. Preferably, the system includes first and second mixing chambers and first and second tanks arranged in series with each of the tanks including drag lines for removing floating and settled contaminants.
Abstract:
The instant invention provides a diffuser comprising a rectangular frame with a tope edge and a bottom edge; a base plate attached to said bottom edge at a base plate perimeter and having a gas inlet through which gas can flow; a top plate with an upper surface and an inner surface said top plate attached to said top edge at a top plate perimeter and having an aperture through which gas can flow; a flexible, generally gas-impermeable membrane lying above said top plate and attached to said top edge at a membrane perimeter, said membrane including a central porous portion with a boundary defined by an ellipse.
Abstract:
In the representative embodiments of diffusion devices disclosed in the specification, a diffusor support member and a flexible sheet-like diffusor are connected in sealing relation along peripheral edges by continuous clamping and sealing arrangements. One form of the clamping and sealing arrangement comprises a U-shaped clamp which embraces the edge of the support member and the peripheral edge of the diffusor. In another form of clamping and sealing arrangement, two strip members held apart by a third strip are inserted into a groove in the support member so as to clamp the diffusor in the groove. Additional strengthening members for the support member and hold-down members for the diffusor are also disclosed.
Abstract:
The invention refers to an aeration installation for introducing a gas, in which a cover is arranged on a foundation, through which the gas is able to penetrate this covering through individual, delimitable sections.
Abstract:
Generally there is provided an elastomeric diffuser membrane configured to overlie a planar base and to wrap around the edge. A plurality of lobe extensions of the membrane protrude under the base and are interconnected by a strap to secure the membrane to the base.
Abstract:
Wastewater and recycled activated sludge are homogeneously mixed in a first aeration zone by injecting an oxygen-containing gas such as air into the lower portion of the zone under conditions which produce a complete mix reaction and sufficient oxygen is supplied to meet the biological oxygen demands of the mixed liquor. The gas is introduced, preferably by a plurality of fine bubble membrane diffusers, in the form of fine bubbles having a diameter less than about 4 mm. The bubbles provide both the mixing to keep solids in suspension and the oxygen required to maintain the overall dissolved oxygen content in the first aeration zone as close to 0 as possible. The mixed liquor is sequentially contacted with an oxygen-containing gas in second and third aeration zones under conditions which produce a complete mix reaction, preferably by fine bubble membrane diffusers, clarified and a portion of the settled sludge is recycled to the first aeration zone.
Abstract:
Intensive fish fattening in open waters is increasingly disturbed by deposits of harmful substances. Fish fattening in artificial ponds is uneconomic because of the considerable outlay in terms of the fresh water and area required. These disadvantages can be overcome by a specially designed fish tank and a new process for operating such fish tanks. The fish tank (10) has, in its longitudinal center axis, a pit (11), into which a filler (31) with vertically extending flow channels (37) is placed. The fish water, together with an air/oxygen mixture, is circulated through these flow channels approximately 30 times per hour. The fish water is purified (nitrified) biologically according to the adhesive activated-sludge process by micro-organisms adhering to the filler. 50 to 500 liters of fresh water per kg of growing fish are added to the fish water, depending on the type of fish.
Abstract:
A diffuser for introducing gas in bubbles into liquid held in an aeration tank comprising a body member having a backing surface and passaging extending from a gas inlet to an outlet at the backing surface, and a flexible, gas permeable membrane covering the backing surface and secured at its periphery to the body member in sealing relationship thereto. The membrane is adapted to distend and move away from the backing surface upon delivery of gas under pressure to diffuser, with the gas flowing through the distended portion of the membrane and into the liquid in the form of relatively small gas bubbles, and adapted to collapse into engagement with the backing surface when gas under pressure is not delivered to the diffuser. A check valve comprising a movable valve member on the membrane and a valve seat on the backing surface enables flow of gas into the space between backing surface and the membrane, and blocks flow of liquid into the passaging in the body member.