Abstract: A system and method to control mixed liquor fermentation in a continuous-flow biological wastewater treatment process that removes organic matter, nitrogen and/or phosphorus provides for real-time adjustment of anaerobic solids retention time to initiate, optimize or cease mixed liquor fermentation in the anaerobic zone. Control is in response to signals from biological sensors monitoring microbial activity. Sufficient volatile fatty acids (VFAs) for the biological treatment process are generated endogenously, without bringing in sludge from primary sedementaiton or elsewhere. Efficiency of the process is increased, resulting in a smaller plant footprint requirement.

Abstract: A clarifier of a wastewater treatment system is made more efficient and cost effective with an energy dissipating inlet (EDI) that removes the need for a conventional feedwell/EDI system. A central influent pipe has wastewater outlet ports under the liquid surface, the ports being surrounded by an efficient EDI surrounding the center pipe and extending outwardly therefrom. The EDI receives influent flow and directs the sludge outwardly and generally downwardly at reduced flow velocity. Series of baffles in the EDI help slow the flow velocity and disperse the sludge. In another embodiment a faucet-type EDI has discharge openings that disperse the sludge downwardly after it has flowed through sets of baffles above. Significant cost reductions in material and installation are realized by elimination of the conventional feedwell/EDI system.

Abstract: A vertical motion mixer has a drive mechanism with two axes of guidance for vertical motion. A reciprocating yoke is fixedly secured to the driving shaft for the mixer, without any guide bearing for the mixer driving shaft. The mixer drive unit is of compact and simplified design with minimal moving parts, and including drive gearing with planetary gears to minimize wear during reciprocating movement.

Abstract: The invention relates to an apparatus for providing ultrapure water, in particular ultrapure water for use in semiconductor fabrication. This apparatus comprises at least one cylindrical reactor with an inner cylindrical shell, an outer cylindrical shell and a channel-like volume between inner shell and outer shell. According to the invention said inner cylindrical shell houses at least one UV emission device, said outer cylindrical shell comprises at least one means for reflecting UV radiation, and said channel-like volume is provided for flowing water through the reactor.

Abstract: A liquid level control system employs a flap gate for discharging liquid, but with a midstream headloss inducing device between the basin or tank and the flap gate. The flap gate opens when liquid level in the basin rises, and the opening of the gate is controlled by a counterweight positioned so as to decrease closing force as the gate opens farther, thus managing the outflow of liquid to efficiently return the basin to a design level. If flow from the basin is generally constant, the system will reach a point of equilibrium of gate opening and closing forces while liquid flows out from the basin.

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.

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.

Abstract: A sealing system for a covered tank, particularly a fixed gas-sealing tank in a wastewater treatment system, includes a thrust ring positioned just inside the tank rim, secured to a series of radial beams for the cover. Preferably supported on corbels anchored to the interior tank wall, the thrust ring has an outwardly extending generally horizontal flange that overlies the edge of the tank rim. To this flange and to the top of the tank rim is secured a flexible membrane seal, around the periphery of the tank. The membrane seal is easily installed, reliable as a seal, and can be efficiently replaced when needed.

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.

Abstract: In a wastewater treatment plant a rag seeding tank is included in a process drain to collect hair and fibers which have passed through headworks of the plant. The hair and fibers tend to join together into large masses downstream of the headworks and can be damaging to process zones, particularly membrane zones. The rag seeding tank includes cartridges filled with surfaces that fibers and hair will attach to, so that hair/fiber rags grow in the seeding tank and are removed therefrom rather than causing problems downstream.

Abstract: Silicon carbide flat sheet filtration membranes are supported on one piece manifold/end cap structures. Ends of a large number of the parallel flat plate membranes are fitted into elongated end cap slots that are part of a single molded manifold/end cap structure, such a structure being at each end of the series of membranes. In addition, a one piece external frame module can be provided to receive the gang of flat plate membranes with attached manifold/end caps. In the event of a damaged plate, the plate can be removed and replaced along with a special end cap repair section. This provides advantages over prior arrangements with individual end caps for each module or potting of the flat plates into a box or chamber.

Abstract: A liquid level control system, which may be used with a clarifier in a sewage treatment plant, manages liquid level of an upstream basin by controlling liquid flow in or out of a system that may use a midstream device to equally distribute flow in or out of the basin. This headloss inducing device creates a non-linear relationship between upstream liquid level to be controlled and the lesser downstream liquid level behind the gate or valve. Without the use of electrical controls, the systems of the invention include a gate or valve with counterforces that manage the outflow stream of liquid while accounting for the non-linear head loss created by the midstream device, thus reaching a desired liquid level range for all system flowrates.

Abstract: An aeration balance controller in a wastewater treatment process allows for precise control of aeration medium in situations where the oxygen concentration must be controlled in more than one aeration zone or compartment, with reduced instrumentation. The system also has application controlling aeration media where the aeration of one or more zones may interfere with the stable control of aeration in another zone. This is accomplished by the use of two control schemes: one which determines the overall aeration effort required, and one or more controllers which adjust the balance between zones to equalize the process error from setpoint from zone to zone.

Abstract: Combined Sewer Overflow (CSO) events require certain minimum treatment, before discharge, according to EPA regulations. However, these events are infrequent, and CSO treatment systems remain idle most of the time. Tertiary filtration is typically used to polish off the secondary treated water in order to remove suspended matter, phosphorous, etc. Tertiary systems are usually designed to handle design flows and remain active most of the time. These are two independent unit operations requiring major capital investment and operational expense. According to this invention an interchangeable system is able to switch a tertiary treatment reactor back and forth between two applications ensuring seamless operation, smooth transition and significant cost savings for treatment facilities.

Abstract: In a wastewater treatment system, a clarifier has a submerged effluent launder, with a sloped, submerged plate that allows clarified liquid to exit through submerged openings. The sloped surface tends to accumulate solids, which can lead to algae growth. Typical internal scum collection system equipment prevents any efficient way to clear the accumulated sludge off the launder surface because of interferences. As disclosed here, a scum discharge area or box is placed external to the clarifier in one embodiment. Scum is wiped from a vertical surface of the launder assembly, above the sloped launder surface, and swept over a scum beach at one position in the clarifier, to drop into a lower trough and the flow out through the clarifier wall to a drop out box or scum discharge area. This allows for a rake-attached, sweeping launder wiper to be moved with the clarifier's rake to remove the accumulation of sludge from the launder's submerged surface, without elaborate moving parts.

Abstract: The invention relates to a method for treating fluoride-containing, in particular HF containing wastewater to remove fluoride and to a corresponding apparatus. In the new method calcium carbonate is reacted in a reaction step at an acidic pH?4 with the fluoride in the wastewater to form calcium fluoride particles. Then, in a subsequent filtration step said calcium fluoride particles are separated by a porous membrane from the treated wastewater. The inventive apparatus comprises at least one reaction container/tank for reacting calcium carbonate at an acidic pH?4 with fluoride in the wastewater to form calcium fluoride particles, as well as at least one porous membrane, in particular at least one porous ceramic membrane for separating calcium fluoride particles from the treated wastewater in a filtration step.

Abstract: A split stabilizer bearing for a mast of a rotary distributor includes a split cylindrical housing, a split filament wound bushing, a plurality of polytetrafluoroethylene-coated carbon fiber ring seals, an annular split seal retainer, and multiple fasteners. The filament wound bushing is disposed inside the housing, along an inner surface thereof. The bushing has a backing layer of high-strength glass fiber and an inner sliding layer of polytetrafluoroethylene (PTFE) and polymer fiber, the two layers both embedded in a epoxy resin matrix. The carbon fiber ring seals are disposed on axially or longitudinally opposed sides of the bushing and along an inner side or surface of the cylindrical housing, preferably in respective annular recesses or offsets along the inner side or surface of the housing. The fasteners, nylon-patch locking screws or bolts, couple the bushing and the split seal retainer to the housing.

Abstract: A thickener/clarifier system includes a thickener/clarifier and one or more sensors measuring respective process or operating parameters of the thickener/clarifier(s) during operation thereof. The sensors are operatively coupled via hard-wired connections and possibly via 4-20 mA converters to one or more wireless transmitters. At least one wireless receiver receives the wireless signal(s) from the transmitter(s). At least one display is hard-wire coupled to the receiver(s) for displaying a magnitude of each process or operating parameter measured.

Abstract: A wastewater treatment system includes a biological treatment plant and an auxiliary, non-biological treatment plant. The auxiliary plant receives overflow, which can be sanitary sewer overflow, combined sewer overflow or strictly storm overflow. Treatment is by coagulation and membrane separation, removing most bacteria. Following treatment the outflow can be discharged to streams.

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.