Abstract: A synergistic composition is provided for controlling odor from waste products. The composition comprises a combination of nitrate salt, sulfide-consuming compound, pH-elevating compound, sulfide-oxidizing, nitrate-reducing bacteria, and sulfide-oxidizing enzyme. The method includes adding a sufficient amount of the composition to a waste stream to provide sufficient sulfide-consuming compound to effect immediate removal of sulfide. The composition incorporates a pH elevating compound, which both decreases the amount of gaseous H2S and puts the aqueous phase into a pH range where naturally occurring bacteria can more easily metabolize the sulfide. The composition also includes one or more nitrate salts which will accomplish longer term prevention of odors. Specific bacteria are incorporated into the formulation to insure that the nitrate has the right type and amount of bacteria present to prevent formation of and/or consume sulfide.

Abstract: A removal system for membranes in a membrane filtration system of the type where the membranes (12) are supported on a membrane support rack (13) in a tank or vessel (6) which, in use, contains liquid to be filtered. The tank (6) comprises a selectively operable opening (9) which in an open position allows the removal of the membranes (12) from the tank (6). The membrane support rack (13) is movable relative to the tank (6) to move said membranes (12) through the opening (9), in its open position, to a position outside the tank (6).

Abstract: A method for managing multivalent metal ion concentrations in low-yield wastewater treatment processes. The method includes combining wastewater containing BOD with bacteria-laden sludge in a mainstream reactor to form a mixed liquor, separating the mixed liquor into a clear effluent and an activated sludge stream, returning a first portion of the activated sludge stream to the mainstream reactor, processing a second portion of the activated sludge stream in a sidestream bioreactor, returning at least a portion of the activated sludge stream in the sidestream bioreactor to the mainstream reactor, and adding multivalent metal ions to at least one of the wastewater, the mixed liquor, the activated sludge stream and combinations thereof to reduce the generation of waste activated sludge.

Abstract: The invention is directed to a method and apparatus for treating wastewater. The wastewater treatment system includes a bioreactor including activated carbon and a first biological population. The wastewater treatment system may also include a membrane bioreactor and/or a wet oxidation unit.

Abstract: A membrane filtration manifold for connecting a filter submodule including one or more elongate bundles of semipermeable polymeric fibers is provided. The manifold includes a housing and connecting collar connected with said housing. The collar is adapted to receive and locate the submodule, where the submodule has a connecting sleeve with a locking formation. The submodule can be secured at one end to the collar by a clip adapted to engage both the collar and the locking formation to prevent axial withdrawal of the submodule from the collar. Also disclosed is a membrane filtration apparatus including a filter submodule including one or more elongate bundles of semipermeable polymeric fibers. The apparatus further includes a membrane filtration manifold removably connected at one end of said filter submodule and a basepiece removably connected to the other end of said filter submodule.

Abstract: Porous polymeric membranes including Halar (poly (ethylene chlorotrifluoroethylene)) and related compounds and the methods of production thereof which avoid the use of toxic solvents. Preferred solvents, coating agents and pore forming agents are citric acid ethyl ester or glycerol triacetate. The membranes may be in the form of a hollow fiber or flat sheet, and may include other agents to modify the properties of the membrane, such as the hydrophilic/hydrophobic balance. Leachable agents may also be incorporated into the membranes.

Abstract: The invention relates to a terpolymer of tetrafluoroethylene (TFE) monomer, polyvinylidene fluoride (PVDF) monomer and hexafluoropropylene (HFP) monomer for forming an ultrafiltration or microfiltration membrane, method of forming said membranes, and to the ultrafiltration or microfiltration membranes themselves. The invention also relates to a method of forming a polymeric ultrafiltration or microfiltration membrane including preparing a leachant resistant membrane dope which incorporates a leachable pore forming agent, casting a membrane from the dope and leaching the pore forming agent from the membrane. The invention also relates to a method of preparing a polymeric ultrafiltration or microfiltration membrane of improved structure including the step of adding a nucleating agent to the membrane dope before casting.

Abstract: In a tank for treating wastewater and including a first plurality of air diffuser elements and a second plurality of air diffuser elements, means for adjusting the relative height of the first diffuser elements with respect to the height of the second diffuser elements in response to changing operating conditions in the tank and changes in the characteristics of the diffusers.

Abstract: A filtration system that includes a plurality of underdrain blocks arranged to define a plurality of laterals. Each underdrain block defines an interior and an exterior and has an orifice that provides fluid communication between the exterior and the interior. The system also includes a plurality of media retaining plates. Each plate includes a plurality of slots that extend through the plate. Each slot has an average width of less than 0.065 inches. Each plate connects to only one of the plurality of underdrain blocks such that the slots provide fluid communication between the exterior and the orifice of the underdrain block to which the plate is attached.

Abstract: A method for removing inert solids from low-yield wastewater treatment processes. The method includes combining wastewater with bacteria-laden sludge in a mainstream reactor to form a mixed liquor, separating the mixed liquor into a clear effluent and activated sludge, returning a first portion of activated sludge to the mainstream reactor, treating a second portion of activated sludge in a sidestream bioreactor prior to returning the second portion of activated sludge to the mainstream reactor, and employing a screening device within the wastewater treatment process to remove inert solids.

Abstract: A phosphorus removal system is operable to remove phosphorus from an influent. The system includes a first section receiving the influent and discharging a first flow. A first coagulant inlet is positioned upstream of the first section and is in fluid communication with the influent to introduce a first coagulant selected to precipitate phosphorus. A second section receives the first flow and discharges a second flow, and a third section receives the second flow and discharges an effluent. A second coagulant inlet is positioned downstream of the first section and upstream of the third section to introduce a second coagulant selected to precipitate phosphorus.