Abstract: A system for distributing both gas and liquid in separate conduits within an underdrain filtration system is disclosed. A tubular liquid conducting conduit also contains a separate air conduit. Extending from each conduit are, respectively, liquid conducting laterals and air laterals. The system is placed within a bed of gravel at the bottom of a filter bed and acts as conventional underdrain blocks and air grids. In a downflow mode, effluent is filtered as it passes through the filter media and filtered water is collected through orifices in the liquid conducting laterals, which in turn feed into the liquid conducting conduit to form a filtrate stream. In a backwash mode, backwash liquid flows through the liquid conducting conduit, out the laterals and up through the filter bed. During backwash, air may be introduced through the air conduit and laterals and rise through the filter media to enhance the effectiveness of the backwash operation.

Abstract: In a travelling bridge filtration system including a tank divided into a plurality of adjacent filter cells, each of the cells containing filter media, a travelling bridge carriage located above the tank and movable along the tank, the carriage supporting a backwash hood engageable with each of the filter cells, the improvement comprising a liquid backwash pump for causing backwash liquid to flow through the cell in a first backwash direction counter to a second filtration direction, and for causing backwash air to be drawn into the cell and to flow in the first direction with the backwash liquid.

Abstract: A water treatment tank for use in a water treatment or softening system is disclosed which is operative in a treatment mode to receive untreated water through an inlet port and to pass treated water through an outlet port, and which is operative in a backwash mode to receive wash water through the outlet port and to pass waste water through the inlet port. Treatment tank has a vessel having an interior cavity which is partitioned into a top headspace portion, and a middle treatment bed space portion, and a bottom headspace portion via the placement of a pair of distributor filters mounted within the interior cavity to extend between the side walls thereof. The filters are spaced-apart, respectively, from the top end wall to define therewith the top headspace portion and the bottom headspace portion.

Abstract: A device for purifying water comprises a filter unit (10) containing an osmotic membrane and provided with an inlet (11), a filtrate outlet (12), a return conduit (14) for a recirculating large flow of unfiltered water and having an outlet (22) for a small flow of reject water,According to the invention, two ion exchange units (17, 18) are arranged in parallel and connected to the filter unit (10) in such way that raw water entering the device is first passed through one of said ion exchange units to be softened, and that the reject water is passed in the opposite direction through the other ion exchange unit to regenerate the same. Valve means (19, 24) are provided for alternately shifting the ion exchange units between the functions of softening and regeneration.

Abstract: A filter apparatus having a backwash head arranged to up-flow backwash one filter cell at a time, and a scavenging means having a fluid intake head arranged to communicate with at least two cell ports at the same time to downflow scavenge each filter cell the first time when the backwash head is in a position to backwash one filter cell and a second time when the backwash head is in a position to backwash a succeeding filter cell. Turbidity monitoring means having a monitor inlet conduit mounted on the fluid intake head, is arranged for communication with the cell port adjacent the end of the fluid intake head that trails during the backwash run, to monitor turbidity of fluid from each cell port only after the associated filter cell has scavenged at least once.

Abstract: A filter for removal of biochemical oxygen demand and suspended solids utilizing multi-layer filtration media. The filter media includes plastic particles, sand, and garnet and is operated under an automatic control condition. Fine filtering is accomplished by a sludge cake which develops at the upstream face of the filter media. For cleaning the filtration media, deposited sludge is removed from the filter bed by backwashing in a short time period at a high strength backwash flow rate.

Abstract: A system and method for the purifying of water passing through the system, the system comprising in combination a plurality of containers; a quantity of particulate material formed of trace mineral granules located within the containers and adapted to remove contaminants from water contacting the granules as the water passes through the containers; a plurality of pipes for feeding water to the first container, and then sequentially to each subsequent container, and then from the last container; injectors operatively associated with the plurality of pipes in advance of the containers to inject ozone into the water prior to the feeding of water to the containers; and pump means to feed water through the pipes and containers in a continuous and automatic cycle of operation.

Abstract: A self-supporting modular underdrain member for use in a liquid filtration system comprises a main body or housing including a pair of longitudinally extending inclined walls which may have a pair of generally triangular transverse walls connecting the inclined walls to one another, the inclined walls each being provided with a pair of longitudinally extending recesses and a plurality of orifices communicating with each of the recesses. A pair of flanges are connected to the inclined walls for attaching the underdrain body to a floor surface so that the inclined walls, any transverse walls and the floor surface define a cross-sectionally triangular underdrain chamber. Two pairs of elongate cover plates are attached to the inclined walls over the recesses to form in each of the inclined walls a pair of longitudinally extending plenums for the equalization of backwash air and water flow. Each of the cover plates being provided with a plurality of spaced slots.

Abstract: An improvement for a filter system which distributes backwash fluid uniformly throughout a bed of granular media is disclosed. The filter system includes a distributor positioned beneath and supporting the media, with the distributor having a plurality of walls which define a primary horizontal conduit and a secondary horizontal conduit. At least one of the walls which define the conduits contains metering orifices that connect the primary conduit to the secondary conduit. The improvement includes at least one baffle positioned within the primary conduit to facilitate uniform flow of backwash fluid from the primary conduit through the metering orifices into the secondary conduit. The baffle may comprise flanges extending from the walls which define the primary conduit normal to a fluid flow direction in the conduit. Alternatively, the baffle may include posts positioned within the conduit.

Abstract: An underdrain lateral for a liquid purification system is described. The lateral has three chambers, a primary chamber, a compensating chamber, and gas chamber. Turbulence is minimized during cleansing of the purification media by isolating the gas from the liquid and the backwash liquid. This is accomplished by feeding gas into the gas chamber so that the chamber is occupied by gas only during cleansing. Orifices in the wall between the primary and compensating chambers and in the baffle between the compensating and gas chambers provide compensation for even distribution of liquid in the lateral. The design also enables the use of cut outs in the gas chambers to equalize gas pressures and flow among the laterals and throughout the system bed and cut outs in the primary chambers to equalize liquid pressure and flow among the laterals and throughout the system bed.

Abstract: A filter apparatus for filtering fluids such as gases or liquids includes a casing defining an inlet and an outlet, and having a peripheral wall extending between the inlet and outlet. The peripheral wall defines a chamber having a longitudinal axis and a cross-sectional area, when viewed in the direction of the longitudinal axis, which increases between the inlet and the outlet. A bed of particulate filtering media is disposed within the chamber, the media ranging in size between relatively large particles disposed adjacent the inlet and smaller particles disposed closer to the outlet. Preferably, the size of the particles is chosen based upon the relationship between the lifting force exerted on the particles by a fluid flowing upward through the chamber and the weight of the particles.

Abstract: A gravity flow, single or multi-cell filter incorporating an integral backwash control chamber for enabling backwashing to occur without the need for backwash pumps. The backwash control chamber contains a volume of backwash liquid, and communicates with a source of pressurized backwash liquid through a float-controlled flow control valve in order to maintain a desired liquid level within the backwash control chamber during backwashing operations. The flow of backwash liquid from the backwash control chamber is controllable either by means of three-way valves interconnecting the backwash control chamber with the filter outlet chamber, or by wash water control gates within the backwash chamber that are adapted to selectively cover outlet openings to permit backwash flow to enter the filter outlet chamber.

Abstract: Methods and systems of the prior art for cleansing a plurality of seriate filter cells in automatic backwash filters by backwashing the cells one at a time with backwash liquid wherein the cleansing operation on the active cell is prevented from moving to a further cell until the contaminant content of the waste liquid issuing from the previous cell reaches a predetermined low level are improved by overriding such prevention even though such content remains too high when a prescribed quantity of waste liquid has issued from the previous cell, e.g., as determined by a timer or fluid meter.

Abstract: A launder and baffle structure, used in association with a filtration tank of the type using granular filtration media, is disclosed which reduces the amount of filtration media lost during a backwashing cycle. The structure of the invention includes an elongated launder, baffle structure system associated with the elongated launder and regulatable air discharge structure associated with the baffle structure system. The structure of the invention is configured to reduce velocity of flow in order to provide settling of filter media from solution and is configured to provide dissipation of air from solution to further enhance quiescence of flow and settling of filter media from solution. The regulatable air discharge system is adjustable to release a selected amount of air from beneath the baffle system in order to regulate turbulence and thereby facilitate quiescence of flow.

Abstract: A process and apparatus for treating contaminated water involving passing water containing contaminants as a stream through a filter to remove the contaminants and form a purified water stream, directing the purified water stream to an effluent discharge outlet and accumulating a portion of the purified water in a reservoir under pressure, preferably through action of a trapped air pocket in the reservoir, and regenerating the filter by using the purified water in the reservoir to back-flush the filter.

Abstract: Systems are described for removing organic solvents such as kerosene-based solvents, from aqueous solutions, in leaching processes for recovering metal such as copper from ore. A unit for recovering small amounts of kerosene-based solvent from raffinate (which comprises acidic water with a small amount of solvent and debris) includes both a plate-type coalescing device (60, FIG. 2 ) and a granular bed (62) in series, and preferably located in the same vessel (54). The raffinate first moves through the plate-type coalescing device where much of the kerosene is removed, to greatly increase the useful period of the granular bed (before it has to be backwashed). In a unit (20, FIG.

Abstract: An improved cap for underdrains in gravity filters has a top surface and a bottom surface with a plurality of tapered screen members defining slots in the top surface. The slots provide communication with the filter bed without passage of fine grain filter media therethrough. The screen members are inclined with respect to horizontal to define a plurality of raised portions in the top surface, each raised portion defining a distribution chamber above the orifices in the distributor. The cap may be included in a capped filter underdrain block having a plurality of ribs and orifices on a top wall of the block. The cap rests on the ribs and cooperates with them to define distribution chambers above the orifices in the top wall of the block. The distribution chambers promote intermixing of air and water prior to introduction to the bed, and the ribs finely meter backwash fluids for even distribution of backwash fluids throughout the entire filter bed.

Abstract: An improved method and apparatus for purifying liquid in a square or rectangular tank involving ultra violet (UV) treatment, oxidation, flotation, filtration, effluent purging and disinfection is described. The liquid to be treated is fed into the mixing chamber of the apparatus in the presence of UV light and an oxident (ozone and/or hydrogen peroxide), and then discharged into the flotation chamber for gas stripping of volatile organic compounds (VOC) and flotation removal of floating substances. The subnatant in flotation chamber flows downward through multiple automatic backwash liquid phase granular activated carbon (GAC) filters for final polishing before being discharged as the liquid effluent or further disinfected. The flotation chamber is hooded for collection of gas stream which is moved by a gas mover and purified by a gas phase granular activated carbon (GAC) filter.

Abstract: In a high speed upward flow filtration apparatus, an upper perforated panel for receiving a fibrous lump is secured to a circumferential side plate for receiving the fibrous lump. A lower movable perforated panel for receiving the fibrous lump is vertically moved by a vertical motion cylinder, and fitted into the circumferential side plate for receiving the fibrous lump under the upper perforated panel for receiving the fibrous lump. A filter layer is formed by filling the fibrous lump between the upper perforated panel for receiving the fibrous lump and the lower movable perforated panel for receiving the fibrous lump. An unfiltered water supply diffuser is provided under the lower movable perforated panel for receiving the fibrous lump. The lower movable perforated panel is raised by the vertical moving cylinder to form a dense and uniform filter layer and to implement a high performance filtration.

Abstract: The present invention comprises apparatus and a method of automatically controlling the permeability of filter beds. In particular, this invention directs itself to filter beds or tanks that are divided into a plurality of contiguous compartments or cells, each compartment containing a filtering media substrate, which substrate is cleansed or backwashed, periodically, when necessary, by a traveling bridge backwash mechanism. The duration and frequency of backwashing is automatically controlled to maintain a desired overall permeability and throughput performance of the filter bed. Permeability control is dynamic to maintain optimum performance under all conditions, i.e. changing in response to fluctuating filter bed hydraulic or solids loading rates.

Abstract: An improved multi-stage treatment system for biological denitrification of and suspended solids removal from water includes a biological reactor containing rigid media supporting denitrifying bacterial growths, an aeration chamber and an automatic backwash filter. In use, methanol or other carbon source containing influent water flows into the reactor beneath the rigid media and upwardly in contact with said bacterial growths to cause nitrates and nitrites contained therein to be converted into nitrogen. The denitrified water is then aerated in the aeration chamber and subsequently filtered by downward flow through the automatic backwash filter.

Abstract: A cap for filter underdrain blocks is provided, wherein the cap has a porous body with a top surface, a bottom surface and downwardly extending flanges. The cap is installed on a filter block having a plurality of orifices in a top wall of the filter block for channelling fluids to and from an overlying filter media. The bottom surface of the cap along with the flanges define a distribution chamber above the orifices, and the cap has a porosity such that a fine grain filter media may be placed directly on the top surface of the cap without media penetrating therethrough and clogging the underdrain blocks. The distribution chamber enhances distribution of backwash fluids throughout the filter media, and the cap eliminates the need for a separate gravel support layer to be installed between the fine grain filter media and the underdrain blocks.

Abstract: A launder and baffle structure, used in association with a filtration tank of the type using granular filter media, is disclosed which reduces the amount of filter media lost during a backwashing cycle. The structure of the invention includes an elongated launder, sloping baffle structure associated with the elongated launder and air discharge structure associated with the sloping baffle structure which releases air from beneath the sloping baffle structure, the air having been dissipated from the fluid. The structure of the invention is configured to reduce velocity of flow in order to provide settling of filter media from solution, is configured to provide dissipation of air from solution to further enhance quiescence of flow and settling of filter media from solution, and directs fluid flow away from the launder. The structure of the invention further includes a wing baffle for dissipating velocity in the fluid.

Abstract: A baffle system is described that significantly reduces media loss caused by turbulence encountered during gas and liquid backwashing of a discrete media filter bed. When positioned about a filter collection trough or outlet, the baffle system deflects rising gas bubbles away from the collection trough and disengages filter media from the backwash liquid.

Abstract: An underdrain lateral for a liquid purification system is described. The lateral has three chambers, a primary chamber, a compensating chamber, and gas chamber. Turbulence is minimized during cleansing of the purification media by isolating the gas from the liquid and the backwash liquid. This is accomplished by feeding gas into the gas chamber so that the chamber is occupied by gas only during cleansing. Orifices in the wall between the primary and compensating chambers and in the baffle between the compensating and gas chambers provide compensation for even distribution of liquid in the lateral. The design also enables the use of cut outs in the gas chambers to equalize gas pressures and flow among the laterals and throughout the system bed and cut outs in the primary chambers to equalize liquid pressure and flow among the laterals and throughout the system bed.

Abstract: A method and apparatus are disclosed for maintaining continuous, long-term microbial control in the water supply for potable, hygiene, and experimental water for space activities, i.e., space shuttle, orbiter lab, Lunar base, Mars base, deep space missions, etc., as well as treatment of water supplies on earth. The water purification is accomplished by introduction of molecular iodine into the water supply to impart a desired iodine residual. The water is passed through an iodinated anion exchange resin bed. The iodine is bound as I.sup.-.sub.n at the anion exchange sites and releases I.sub.2 into the water stream flowing through the bed. Suitable anion exchange resins are Amberlite IRA 401S (Rohm & Haas); Dowex SBR (Dow Chemical); and Ionac ASB-1P (Sybron Corp.). The concentration of I.sub.2 in the flowing water gradually decreases and the ion-exchange bed has had to be replaced.

Abstract: Systems and methods for clarifying liquids, especially water, of the two stage upflow/downflow type that operate in a filtering mode, a first stage flush mode and a bistage backwash mode are improved by the use in the first, upflow stage of particulate filter media consisting of solid particles with a specific gravity of between 3.5 and 4.4 and a size between 1.5 and 4 mm. and, preferably, in the second, downflow stage particulate filter media consisting of solid particles having a specific gravity of between 1.5 and 4.0 and sizes of between 0.3 and 1.5 mm and providing for upward passage of gas bubbles through the first stage media particles without appreciable expansion thereof during at least part of each flush and backwash mode of operation.

Abstract: An air duct block for air/water underdrain systems in gravity filters comprising a row of interconnected air duct blocks positioned below the filtering media and extending transversely to the underdrain laterals. Each air duct block is in communication with at least one adjacent individual underdrain filter block to supply backwash gas thereto during backwashing operations, thereby supplying backwash gas to its associated lateral. Each air duct block is in further communication with at least one adjacent air duct block such that backwash gas flows between the interconnected air duct blocks and along the row of air duct blocks. This system supplies backwash gas to the entire underdrain system through a single pipe from a source of supply.

Abstract: An underdrain lateral for a liquid purification system is described. The lateral has three chambers, a primary chamber, a compensating chamber, and gas chamber. Turbulence is minimized during cleansing of the purification media by isolating the gas from the liquid and the backwash liquid. This is accomplished by feeding gas into the gas chamber so that the chamber is occupied by gas only during cleansing. Orifices in the wall between the primary and compensating chambers and in the baffle between the compensating and gas chambers provide compensation for even distribution of liquid in the lateral. The design also enables the use of cut outs in the gas chambers to equalize gas pressures and flow among the laterals and throughout the system bed and cut outs in the primary chambers to equalize liquid pressure and flow among the laterals and throughout the system bed.

Abstract: A radioactive waste liquid treatment apparatus according to the invention comprises an upstream-side filter unit having an inlet for radioactive waste liquid, and a downstream-side filter unit communicating with the upstream-side filter unit and having an outlet for filtrated liquid. Further, the upstream-side filter unit includes first filter member installed therein having active silica for removal of interfacial active agents and oil, whereas the downstream-side filter unit includes second filter member installed therein, and this second filter member has a vapor permeable membrane.

Abstract: There is disclosed a granular filtration system having a separator trough with an air deflection baffle of improved shape and operation, preferably combined with an airlift mechanism for cleaning or removing settled granular media particles from the upper surface of the air deflection baffle. The air deflection baffle is used in a regeneration method for the granular media filtration system in which the granular media is purged of filtered solids by backflushing with air and water. In this application, the air-deflection baffle is installed beneath and adjacent to the open throat of a solids separation vessel, typically which is in the form of a trough spanning the width of the filtration vessel and having an inclined bottom wall with an open throat. The improved configuration of the air deflection baffle is generally an inverted W-shape. A plurality of open-ended tubes are secured on the air deflection baffle, transversely to the longitudinal axis thereof.

Abstract: A cap for filter underdrain blocks is provided, wherein the cap has a porous body with a top surface, a bottom surface and downwardly extending flanges. The cap is installed on a filter block having a plurality of orifices in a top wall of the filter block for channelling fluids to and from an overyling filter media. The bottom surface of the cap along with the flanges define a distribution chamber above the orifices, and the cap has a porosity such that a fine grain filter media may be placed directly on the top surface of the cap without media penetrating therethrough and clogging the underdrain blocks. The distribution chamber enhances distribution of backwash fluids throughout the filter media, and the cap eliminates the need for a separate gravel support layer to be installed between the fine grain filter media and the underdrain blocks.

Abstract: Improved methods are disclosed for cleansing a plurality of seriate filter beds in automatic backwash filtering systems by backwashing the beds one at a time with backwash liquid from an effluent channel common to seriate effluent ports of the plurality of filter beds and pumping the backwash liquid seriatim through separate effluent ports of individual filter beds and then flowing filtered effluent from each bed through its effluent port into the effluent channel, repeating such steps of backwashing and flowing filtered effluent on individual filter beds until all the filter beds in the system have been backwashed wherein, simultaneously with the backwashing of a second bed, waste liquid from the first bed is pumped through its port while the waste liquid is monitored for turbidity and such waste liquid pumping is continued until the turbidity thereof reaches a predetermined low level.

Abstract: A multiple tank filtration system can be backflushed to remove the material on the loaded adsorbent at a high rate of liquid flow through the use of a tank connecting distributor which has pervious projections extending therefrom into both the first and second tanks. The pervious projections extending into the first tank are less than those which extend into the second tank. This provides for a greater flow of liquid during backwash.

Abstract: Declining rate filtration systems using influent siphoning for influent flow to a bed of particulate filter media are improved by using at least two influent siphons with each filter bed. In use of such improved systems, influent is siphoned from a flume source or the like to the filter bed after backwashing of the filter media through a first siphon and, thereafter as headloss in the filter bed increases, further influent from the source is siphoned to the filter bed through a second siphon that has an effective minimum cross-sectional area substantially greater than that of the first siphon.

Abstract: The filtration system provides a long horizontal flow path through buoyant filter media. The filter media is contained in a vessel and the relationship between the water level in the vessel and the amount of filter media is such that the media extends completely across the horizontal flow path of the water during the filtration mode of operation. The system is configured so that the buoyant media volume expands during a cleansing mode of operation.

Abstract: A method of repurifying water from a public supply, comprising the steps of:taking water to be repurified continuously from the public supply;filtering the water slowly through a volume of particulate material; andaccumulating the filtered water to provide a store of repurified water for later use as and when required.According to a second aspect of the present invention, there is provided an apparatus for repurifying water from a public supply, comprising:a water inlet adapted for connection to the public supply and operable to take a continuous flow of water from the supply;a filter comprising a volume of particulate filter material and arranged to receive the water from the water inlet;a container arranged to receive filtered water therefrom and to store the filtered water;and a water outlet connected to the container and operable to draw off filtered water as and when required.

Abstract: A filter block having a plurality of exterior and interior walls defining a plurality of interior chambers, said chambers including at least a first and second conduits parallel to the longitudinal axis of said block, one disposed above the other, with a third conduit provided to supply gas under pressure to the upper conduit; a top exterior wall of the block having a plurality of apertures distributed thereover. The interior chambers comprise separate conduits for both gas and liquid backwash flows. The interior walls defining the conduits are disposed to provide even distribution of the backwashing gas and to provide bearing support for the top wall of the block.

Abstract: Plant to precipitate suspended matter out of water, such as surface run-off water, industrial waste water, biologically treated waste water and landfill leachates with in-pipe flocculation, a filter filled with granular filter material situated above the sedimentation tank of the plant the direction of flow through which is from top to bottom and a backwash tank and whose subsequent sedimentation and filtration stages comprise the following features: that the backwash tank for filtered water is situated above the filter; that a float seals off an aperture with an enlargened cross-section connecting the filter with the backwash tank in a position raised by buoyancy; that a bypass directs the treated filtered water past the float to the backwash tank if the said aperture is closed off; and that the sludge outflow pipe in the floor of the sedimentation tank and the sludge valve in the sludge outflow pipe are directed against gravity to such an extent that when the sludge valve in the sludge outflow pipe is opene

Abstract: Automatic backwash filter systems including a filter tank divided into a multiplicity of seriate cells of substantially the same width by a plurality of vertical rectangular cell sheets are improved by provision of new spacer assemblies to mitigate bowing of the cell sheets during backwashing or other operations applied to the cells. Such spacer assemblies include horizontally aligned bores that extend through each cell sheet adjacent their top, one or more stringers that extend through the bores, and a plurality of tubes of approximately the same length substantially equal to the width of the cells. One of such tubes is positioned in each filter cell surrounding the stringer present in such cell and between the surfaces of the respective cell sheets. Where a plurality of stringers are used in the spacer assemblies arrangements are disclosed for making final connections to complete the assemblies.

Abstract: Improved methods are disclosed for cleansing a plurality of seriate filter beds in automatic backwash filtering systems by backwashing the beds one at a time with backwash liquid from an effluent channel common to seriate effluent ports of the plurality of filter beds and pumping the backwash liquid seriatim through separate effluent ports of individual filter beds and then flowing filtered effluent from each bed through its effluent port into the effluent channel, repeating such steps of backwashing and flowing filtered effluent on individual filter beds until all the filter beds in the system have been backwashed wherein, simultaneously with the backwashing of a second bed, waste liquid from the first bed is pumped through its port while the waste liquid is monitored for turbidity and such waste liquid pumping is continued until the turbidity thereof reaches a predetermined low level.

Abstract: An improved apparatus and method for operating a granular medium filter is disclosed. The apparatus comprises an improved underdrain structure made up of a plurality of rectangular compartments which allows the filter bed to be "air pulsed" as well as backwashed for thorough cleaning of the bed. Nozzles are positioned within the rectangular compartments and directed vertically into the filter bed. Fluid from the nozzles helps to break up the bed during backwashing as well as countereact size classification of the medium during this process. The method of operating a filter with the improved underdrain structure is also described.

Abstract: A flume distribution system includes a distributor having a stationary lower portion and a removable upper portion. The lower portion defines a duct which is in fluid communication with a flume and at least one underdrain lateral. The lower portion also includes an apertured end wall which abuts one of the underdrain laterals at a lateral inlet, and a stop is disposed within the duct and spaced from the end wall. The duct receives a removable orifice plate which is adapted to pivot between a slant inactive position abutting the stop and an upright active position restricting the aperture in the end wall. During backwash operations, water is introduced to the flume and enters each duct in the lower portion of the distributor, and the pressure of the incoming water causes the orifice plate to pivot from the slant position to the upright position, reducing the cross-sectional area of the aperture in the end wall and thereby regulating the velocity of backwash flow from the flume into the lateral inlet.

Abstract: An improved apparatus and process for the operation of a down-flow granular medium bed filter is disclosed. A splash plate for dissipating the force of influent liquid is rotatably connected to support means, allowing the plate to rotate from a position parallel to the bed surface to a position perpendicular to the bed surface upon the liquid above the bed rising to a selected first level. The splash plate is maintained in the perpendicular position for the remainder of the filtration cycle, the backwash cycle and any chemical cleaning cycle, allowing unobstructed operation of the filter bed. The splash plate returns to the original position at the start of another filtration cycle.

Abstract: The invention comprises an improvement in a cleaning apparatus particularly useful for filters. A mechanism drives a hood into position adjacent partitions. A sealing member is selectively actuated to seal off at least one such compartment for cleaning while the remainder of the filter remains in service. Sealing is accomplished by interaction between the hood and the partitions. The invention also relates to techniques for selectively bringing the hood into contact with the partitions, and a construction of the hood and a media support plate which allows flexibility to lilft and scour the filter media using a gas to dislodge impurities, coupled with a liquid backwash involving drawing filtered water back through the media to carry away the impurities out of the filter.

Abstract: A liquid treatment multi-stage process and apparatus thereof for removing dissolved, colloidal, volatile, suspended and living contaminants from water, wastewater or sludge streams which includes chemical feeding, static mixing, gas pressurization, hydraulic flocculation, sedimentation, flotation, adsorption, filtration and disinfection by converting dissolved solids to insoluble forms by oxidation and chemical precipitation, coagulating and clarifying colloidal substances and microorganisms, adsorbing, filtering and disinfecting the remaining contaminants in the liquid to produce a purified liquid.

Abstract: An underdrain lateral for a liquid purification system is described. The lateral has three chambers, a primary chamber, a compensating chamber, and gas chamber. Turbulence is minimized during cleansing of the purification media by isolating the gas from the liquid and the backwash liquid. This is accomplished by feeding gas into the gas chamber so that the chamber is occupied by gas only during cleansing. Orifices in the wall between the primary and compensating chambers and in the baffle between the compensating and gas chambers provide compensation for even distribution of liquid in the lateral. The design also enables the use of cut out in the gas chambers to equalize gas pressures and flow among the laterals and throughout the system bed and cut outs in the primary chambers to equalize liquid pressure and flow along the laterals and throughout the system bed.

Abstract: A water filtration multi-stage process and apparatus thereof for removing dissolved, colloidal, volatile, suspended and living contaminants from water or wastewater which includes chemical feeding, in-line static mixing, filtration chemical monitoring and optimization, aeration, hydraulic flocculation, grit settling, adsorption, filtration, disinfection, and final water conditioning by converting dissolved solids to insoluble forms by oxidation and chemical precipitation, and then by filtering the insoluble contaminants, adsorbing residual dissolved contaminants, disinfecting the living microorganisms, and applying magnetic or electronic field for conditioning to produce a purified water.

Abstract: A multiple filter, gravity flow, liquid filtering apparatus includes a plurality of adjacent independent filter chambers with common influent and effluent passages surrounding a centrally located effluent control chamber and having provisions for backwashing at least one filter chamber with the effluent from companion filter chambers. The effluent control chamber preferably has two sections, a lower section which serves to collect filtrate from each of the surrounding filter chambers through a plurality of flow transfer ports which communicate with each filter chamber, and an upper section which houses equipment and controls for filtering and backwash operations. In one embodiment, the lower section includes a vertically disposed outlet conduit with an adjustable weir located at the open end of the conduit. The weir is used to adjust the liquid level in the lower section of the control chamber to control filtering and backwash operations.

Abstract: A filter underdrain apparatus comprises plate means forming a plurality of horizontal distributor conduits, the conduits being in juxtaposed, laterally-spaced relationship and constructed and arranged to defined alternating conduits and troughs of a filter underdrain. At least some of the horizontal distributor conduits include interior partitions extending along such conduits and dividing the interior of each such conduit into a liquid passage and a gas passage. Liquid metering orifices communicate the interior of the liquid passage with the exterior of the distributor conduit for substantially evenly distributing backwash liquid flows from the liquid passage and for passing filtered liquid flows into the liquid passage. Gas metering orifices communicate the interior of the gas passage with the exterior of the distributor conduit for substantially evenly distributing gas from the gas passage when connected with a pressurized gas source.