Abstract: A single chamber filter module containing a buoyant bed of filter particles through which the fluid to be filtered is passed in an upward direction through the bed so that the solids become trapped within the bed. The filtrate is withdrawn from the upper end of the module. Periodically, the filter bed is rehabbed by dispersing the bed, washing the entrapped solids from the particles and discharging the solids from the lower end of the module.

Abstract: A coarse media flocculator utilizes buoyant media restrained against upward movement in a vertical chamber whose cross-sectional area increases uniformly in the direction of flow, thereby providing a uniformly tapering velocity gradient. The height of the media restrainer within the chamber can be adjusted, thereby changing the depth and cross-sectional characteristics of the media bed within the tapered chamber. The velocity gradients of the flocculator can thus be changed independent of flow. A washwater piping grid with downwardly pointed jet spray nozzles is positioned within the media bed for cleaning. The height of the media bed can be adjusted by changing the position of the media restrainer or by changing the liquid level within the chamber, thus changing that part of the media bed where the jet spray is concentrated. In one embodiment, the restrainer is disposed within an area of the chamber above the tapered portion having a uniform cross-section.

Abstract: A liquid filtration system is provided which includes a traveling bridge device mounting air scour and backwash means for successively cleaning each of a plurality of filter cells formed in a filtration tank. The air scour means includes a first hood open to atmosphere and adapted for sealing engagement with each filter cell. The first hood may include an air scour inlet conduit for supplying air under pressure to each cell. The backwash means includes a second hood also adapted for sealing engagement with each filter cell and includes a backwash conduit for creating suction within each filter cell. In one embodiment where the air scour pump is mounted on the traveling bridge carriage, each cell is provided with a vertical riser adapted for sealing engagement with the air scour inlet conduit in the air scour hood. In an alternative arrangement, the air is supplied from a ground installed pump, through a common inlet manifold, to the individual cells.

Abstract: An improved water neutralization apparatus is disclosed comprising an elongated vertical cylindrical tank having an upper inlet and lower outlet openings. Water distributors are assembled to the tank at its upper and lower openings. A dual-seal valve is used to automatically shift water flow from normal to backflush flow paths upon actuation of a controller, comprising a timer-operated valve in a drain line connected to the dual-stem valve. In the preferred embodiment, the neutralizing mineral is 98% pure calcium carbonate.

Abstract: An improved unit for removal of nitrates from water is disclosed, which features a cylindrical tank containing a nitrate-adsorbing resin bed and a dip tube/water distributor assembly. The assembly comprises a dip tube extending from an orifice in the upper portion of the tank to a lower distributor assembly, and an additional backflush tube having an open end disposed near the lower distributor assembly and communicating with an upper distributor located beneath the surface of the resin. A water flow restrictor is provided in the lower distributor assembly, such that when water is passed downwardly through the dip tube in a backflush mode, some of the water is squirted into the additional backflush tube, so that the backflush water flows into the resin bed at both its lower and upper portions. In this way, the resin bed is more effectively regenerated by subsequent supply of a brine solution than if the rinse water were only injected at the lower portion of the resin bed.

Abstract: A water filter formed of an upright closed vessel having water inlet and outlet openings adjacent the top thereof, an outlet pipe extending within the vessel from the water outlet opening to adjacent the vessel interior bottom, a permeable barrier filter positioned within the vessel adjacent the interior bottom and affixed to the lower end of the outlet pipe, the vessel being filled with a particulate filter medium, preferably charcoal or the equivalent, the filter medium surrounding the barrier filter, and the barrier filter being formed by a short length tubular wall of impervious material having an opening in the tubular wall, a filter inlet pipe received in the opening in the tubular wall and extending within the housing, the end of the filter inlet pipe within the housing being closed and the pipe having a plurality of small openings therein, two semi-circular permeable foam plastic filter members within the interior of the housing, the semi-circular filter members being the thickness substantially that

Abstract: A filter distributor is disclosed which includes a plurality of radially-extending conduits or laterals pivotally mounted at their inner ends on a hub and extending to outer ends substantially adjacent to the outer wall of the filtered tank. Each lateral is provided with an inner strainer and an outer strainer. The outer strainers are sized to service an adjacent zone along the outer portions of the tank and the inner strainers are sized to service adjacent inner zones. In the illustrated embodiment, the outer strainers have an open flow area twice as great as the inner strainers and service the outer two thirds of the tank. The strainers are positioned substantially at the centroid of the adjacent zones which they service. The sizing of the strainers and their location is arranged so that substantially uniform flow occurs through all of the filter medium during normal filtering operation and backflow operations.

Abstract: A filter includes a bed of particulate solids for removal of contaminants from a fluid directed in a downstream direction therethrough. A barrier is located downstream of the bed of particulate solids and includes an anchoring member having flexible members joined thereto and projecting outwardly therefrom. The flexible members are closely spaced to each other for providing a closely-spaced network of flexible members to establish multiple barrier layers in the downstream direction of fluid flow through the barrier. In one embodiment the barrier is in the form of a planar member generally coextensive with a bottom wall of the filter and includes a plurality of anchoring members spaced-apart horizontally from each other. In another embodiment the barrier is in the form of a strainer with the anchoring members being spaced-apart vertically from each other and with the flexible members joined thereto being spaced transversely along the anchoring members to provide the multiple barrier layers.

Abstract: A piping and flow control system for a wastewater reactor having a reaction vessel includes an influent distribution and sludge withdrawl conduit located near the bottom of the reactor, and aeration device located within the reactor, a treated effluent decanting system and an automatic control mechanism including a liquid level sensor. The influent distribution and sludge withdrawl conduit along with the aeration device are selectively flow connected with a pumping mechanism by a piping manifold which is also selectively connected to a source for influent wastewater to be treated by the reactor and sludge disposal.

Abstract: A 5/2-way commutating valve, particularly for reverse-flush filters in water treatment plants, consists of a tubular housing with five radial pipe connections (6, 9, 10, 11, 12), between which a valve seat (24 to 27) is present in each case. Preferably spherical valve elements (28 to 30) are arranged on a central rod (23) stressed in one direction by a spring arrangement (32), a double-sided value element (29) cooperating with the two central valve seats (25, 26) being slidable longitudinally relative to the central rod (23). The housing is composed of a plurality of mutually rotatable housing parts (16 to 20) each exhibiting a pipe connection. A flow throttle (51, 23) installed between the spigots (9 and 12) in the housing serves to adjust the flow velocity during reverse flushing. A compressed air piston, which is connectable to the compressor of a ozone generator, may be provided to actuate the central rod (23) counter to the spring arrangement (32).

Abstract: An ion exchange apparatus in which granular exchanger material is deposited to a level above a horizontal drainage for the regeneration medium solution of an ascending countercurrent regeneration process and considerably below an upper liquid connection. A timing generator that divides the regeneration phase into flow segments and rest segments is provided. To reduce the amount of regeneration medium required while changing only slightly the flow resistance and improving the exchanger efficiency, the concentration of the regeneration medium solution is increased to a value that without the timing generator leads to poor utilization of a given amount of regeneration medium. An additional layer of exchanger material excluded from the regeneration process is deposited to a level considerably above the drainage. An intermediate layer of exchanger material extends to a level considerably below the drainage, adjoins the additional layer, and can be mixed with the latter via a mixing device.

Abstract: Apparatus for treatment of septic tank effluent to remove suspended particles for clarifying and purifying the water prior to discharge into the leaching field or for use for other purposes. The apparatus, which is small enough to be conveniently installed in individual households, comprises a vertical main tank, flocculation material supply means to form flocs for combining with suspended solids in the unclarified water introduced into the main tank, a water electrolysis unit in the main tank for producing gaseous bubbles to which the flocs become attached and which rise to the surface where the entrapped solids are removed and returned to the septic tank, and a filter device at the bottom of the main tank for removing remaining precipitated flocs with entrapped solids. The anode of the electrolysis unit is made of aluminum to provide aluminum hydroxide as a flocculating agent.

Abstract: A filter for use in conjunction with an intrachannel clarifier is provided comprising an enclosure, positionable within a channel and connectible to an intrachannel clarifier, and having a floor and sides; a filter compartment fixed within the enclosure, and having sides, either connected to or coincidental with the sides of the enclosure and segregating the interior of the filter compartment from the remainder of the enclosure; a porous medium support, fixedly connected to the sides of the enclosure and positioned within the filter compartment; a bottom, below the medium support and fixedly connected to the sides of the filter compartment; a filter medium, positioned within the filter compartment above the medium support; a conduit, connecting between the interior of the filter compartment beneath the medium support and the interior of the enclosure; a liquid dispersion mechanism, positioned within the filter compartment above the filter medium, for receiving liquid from outside the enclosure and dispersing

Abstract: There is provided an improvement in a waste effluent filter of the type including a tank, a generally flat fine mesh screen over the lower portion of the tank to define an underdrain cavity below the screen and a filter bed of particulate material having an upper surface and a lower general surface adjacent the underdrain cavity. The particle size of the particulate material being greater than the size of the apertures in the fine mesh screen. The filter improvement includes a jet creating grid for creating a plurality of upwardly directed hydraulic jets evenly distributed throughout the filter bed during the filtering of the effluent through the bed wherein the jet creating grid includes a plurality of nozzles in the bed itself substantially below the upper surface of the bed and above the fine mesh screen a selected distance to retain the lower layer of the bed undisturbed.

Abstract: Filtering apparatus of the sand-circulating type in which the backwashing conduit means, by which the filtering medium is circulated from the bottom of the bed to the top and washed in the process, are located around the periphery of the vessel. The conduit means may comprise a series of tubes, each associated with a water jet and equispaced around the vessel wall. Emerging from the tubes, the washed medium may be constrained to pass radially inwards between upper and lower guiding baffles before finally falling onto the top of the bed. The support plate on which the bed rests may be upwardly conical in shape, may contain water nozzles to help direct the lower part of the bed towards the backwashing conduit, and may be formed with perforations through which filtrate may pass.

Abstract: A filter employing a discrete particle filter medium (3,11), such as graded sand or the like, in which the outlet passage (6) located at the bottom (1, 29,8) of a bed of filter medium is provided in which air can be employed in the backwashing process to agitate the filter medium. The filter has shallow coarser layers (9,10,28) of particulate material beneath the filter medium (11) itself and one set of outlet nozzles (14,19,27) having appropriately dimensional perforations positioned in the coarser or coarsest particle layer (9,28). In addition further finer perforated surfaces (16,23,30) communicate with the bottom of the filter medium (11) itself and the arrangement is such that when air is introduced perparatory to, or during backwashing the air emerges predominantly from the elevated finer perforated surfaces (16,23,30).

Abstract: A water filtering device has a substantially horizontal rotatable drum having a filter layer composed of a granular filter material and a space therein, the rotatable drum being rotatable about its own axis, a first water flow pipe extending axially into the rotatable drum in coaxial relationship, the first water flow pipe having a first branch extending radially outwardly in the space for introducing crude water to be filtered into the rotatable drum and discharging waste washing water out of the rotatable drum, and a second water flow pipe extending axially into the rotatable drum in coaxial relationship, the second water flow pipe having a second branch extending radially outwardly in the filter layer for discharging filtered water out of the rotatable drum and introducing washing water into the rotatable drum. The rotatable drum is rotatably mounted on the first and second water flow pipes. The first and second water flow pipes are fixedly mounted on a support base.

Abstract: High rate filtration system includes an upflow filter vessel containing a bed of buoyant media followed by a downflow filter vessel containing a bed of nonbuoyant media. The upflow filter vessel is unobstructed by cross-sectional, media-confining screens. A horizontal trough structure collects filter effluent and makes it possible to clean the bed by diffusing air into the liquid below the bed so that average fluid density in the bed is reduced. The reduction in fluid density results in expansion of the bed as media particles descend by gravity.

Abstract: The invention relates to a process for internal regeneration of mixed bed filters in which, after the exhausted ion exchanger mass has been separated into the two components and these have been regenerated and washed out, the exchanger layer in the region of the cation exchanger/anion exchanger interface is selectively removed from the mixed bed filter, the cation exchanger remaining in the filter is mixed with the anion exchanger remaining in the filter for the new loading stage, the ion exchanger mass removed from the filter is added again, when the work cycle has ended, to the exhausted ion exchanger mass before or during the separation into cation exchanger and anion exchanger, and, after the separation, the loading stage is started again with the regeneration of the cation exchanger and anion exchanger; and also to a mixed bed filter for carrying out the process.

Abstract: A filtration apparatus comprising a filter tank, a support provided at least at a lower interior portion of the filter tank, a filter medium layer composed of fiber lumps accumulated on the support, a filter medium spreading zone provided within the filter tank above the support, air injecting means disposed under the filter medium layer, prefilt inlet means disposed at an upper portion of the tank, and filtrate outlet means disposed at a lower portion of the tank. The apparatus is simple in construction and easy to operate, assures depth-type filtration with high accuracy and is easy to wash for the reuse of the filter medium.

Abstract: A water purification device comprises a raw water channel forming plate extending spirally along the inner wall of a filter tank. A collector for collecting filtered water, positioned in the layer of the filter medium substantially at the center of the raw water channel forming plate, is also disclosed. Since the raw water is filtered from the periphery of the layer of the filter medium and the continuous raw water channel formed by the spirally extending raw water channel forming plate enables the number of influx points of raw water into the raw water channel to be reduced to one at a minimum, the structure is simplified and manufacture costs are reduced.

Abstract: In a water purification apparatus in which a granular filter medium is washed by agitation imparted to the filter medium, a pipe adapted for collection of purified water is mounted within the heap of precipitated granular filter medium and enclosed by a filter mesh to prevent outflow of the filter medium. Sliding contact elements such as turns of a wire wound about the collecting pipe or linear brush-like members inserted on the collecting pipe are also provided between the pipe and the filter mesh so that both the inner and outer surfaces of the filter mesh may be cleaned during countercurrent washing of the filter medium for assuring optimum water permeation at all times.

Abstract: A water purification device includes a plurality of tiers of flow channel or passage defining plates along the inner surface of the wall of a filter tank, a water collecting strainer at about the center of the tank for collecting purified water, and raw water distribution conduit means for distributing and supplying raw water to the respective flow channels. Since raw water permeates into the filter layer in the tank not only from above but from below and from the peripheral zone of the tank, and the purified water is collected at the center and drawn to the outside, the filtration efficiency is improved as compared to the case where raw water is permeated into the filter medium from above and the purified water is collected at the bottom of the tank.

Abstract: A system for handling exhausted vermiculite cation exchange particles after they have been used for the removal of heavy metal ions from waste effluents. The exhausted particles are stabilized and removed from the ion exchange column. Stabilization may be by acid solution recirculation through the column prior to particle removal. This is accomplished by preferably using a portable stabilization unit. The stabilized particles are removed from the column by a flushing, backwashing arrangement. After drying, the particles, which are non-hazardous, may be used in a land fill or they may be expanded to produce a lightweight aggregate, insulation, or agricultural material.

Abstract: A biological filter system has a bed of buoyant granules a portion of which xtends above the surface of the fluid. The bed is disposed above the effluent outlet. Distubutor and receiving means are provided by which the filter can be backwashed.

Abstract: A filtration system includes a deep-bed type filter to receive an inflow of a waste water when the system is in a filtration mode. A distribution plenum within the filter distributes the waste water to an upper and lower portion of the filter bed. As the waste water flows to conduits centrally located within the bed, particulate in the waste water is entrapped by filter media comprising the bed. The waste water is discharged from the system in a clarified condition. Periodically the system is placed in a rejuvenation mode wherein a series of circuits are used to remove the entrapped particulate from the filter bed so that the system may again be returned to its filtration mode to process additional waste water.

Abstract: A countercurrent liquid-solid contacting apparatus having combined filtering and regenerating columns stacked one above the other. The filtering column has a liquid inlet and outlet, a liquid medium to be filtered being supplied into the filtering column through the liquid inlet and discharged to the outside through the liquid outlet after having passed upwardly through a bed of filtering material within the filtering column. The regenerating column has its bottom end opening into the filtering column and supplies a filtering material in an amount necessary to compensate for a reduction in the amount of the filtering material within the filtering column each time a portion of the filtering material in a lower region of the filtering column is withdrawn and then transported back into the regenerating column.

Abstract: An apparatus for separating suspended solids from a liquid includes a tank, a floating bed of granular filter material held at the upper portion of the tank at the time of filtration, a feed pipe for feeding the liquid at a position between a filtering section and a sedimenting section, a hollow member or members which are arranged within the tank at a position below the position of the filter bed but above the position of the feed pipe, an air supply pipe which blows air up through the hollow member or members, thereby creating a turbulence required for effective backwashing, an arrangement for bringing the filter bed down to a position where the lowermost surface of the filter bed is held below a position substantially flush with the top end of the hollow member or members, a means for discharging a filtrate from the tank which is arranged in the top portion thereof, and a means for discharging a deposit of the suspended solids from the tank, which is equipped at the bottom portion thereof.

Abstract: An upwash sand filter with a diaphragm hold-down for the granular filter media during filter stage is operable with self-graded coarse-to-fine media for upflow filtration, downflow filtration, or combined up and down flow to a central exit filtration. The media is held in place by a diaphragm that may be a perforated plate for allowing liquid to pass through the perforations, and in the downflow embodiment, the media column is supported on another perforated wall or plate to allow a final lower layer of coarser media to be used so that the plate itself is not the finest layer of the filter. In the upflow embodiment, a coarser top layer is employed for this same purpose. The diaphragm serves in all embodiments to prevent loss of media and avoid channeling through the media thereby allowing exceptionally high filter rates.

Abstract: A countercurrent liquid-solid contacting apparatus comprises a liquid purifying column for substantially purifying a liquid by passing the liquid upwardly through a bed of purifying material and a regenerating column for regenerating the purifying material used fo purify the liquid. The liquid purifying column includes supply and transfer ports defined respectively at the top and bottom thereof and has therein the bed of purifying material which is spaced a predetermined distance from the top of the liquid treating column to provide a vacant space. The purifying column further includes a liquid inlet and outlet with a portion of the purifying bed above the liquid outlet serving as a settling layer to avoid any possible fluidization and/or expansion of the purifying material.

Abstract: Heavy metal ions are recovered from a dilute aqueous solution by flowing the solution through either a single bed of ion-absorbing material in successive forward and reverse directions, or through a first bed of ion-absorbing material and thereafter through a second bed of ion-absorbing material in the reverse directon of flow. The reversal of flow is to periodically mechanically agitate a bed of ion-absorbing material to dislodge contaminants, such as gelatin.The method is accomplished by using one enclosed vessel, or a pair of enclosed vessels, that have valves to control the direction of flow. A timing device preferably automatically reverses the direction of flow about each hour.After a relatively large number of reversals of flow the heavy metal ions are recovered from the ion-absorbing material and the same is regenerated in the process to again absorb ions from the dilute aqueous solution.

Abstract: A liquid treating system having a tank with a multiplicity of cells, the bottom of each cell converging downwardly toward a drain, and means for backwashing one or more of the cells while the remaining cells continue treating the liquid. Also described are a barrier for separating the cells and a kit for making the barrier.

Abstract: Filter apparatus for removing fine solids from aqueous effluents, e.g., waste water filtration, comprises horizontal upper and lower rigid filter plates formed of aggregate fixed in a matrix of cured organic resin defining therebetween a secondary filter zone containing loose filter media, first and second fluid confining chambers above and below said filter plates respectively from which liquid can flow through the filter plates, a vertical conduit for conducting liquid from beneath the lower filter plate for discharge into the first chamber through an opening in the upper filter plate, conduits for inlet and outlet of liquid to said secondary filter zone and second chamber and a sparger to spray wash water on the top surface of the upper filter plate. In a filtering mode, the liquid suspension to be filtered flows into the first chamber via said vertical conduit and then passes, in turn, through the upper filter plate, the filter zone, the lower filter plate and the second chamber to discharge therefrom.

Abstract: A flow distributor for a fluid bed reactor includes means for decreasing velocity of incoming liquid streams in a uniform, non-turbulent fashion. Inlet ports communicate with fluid portals having divergent walls to slow incoming flow. The fluid portals feed liquid flow to a plurality of diffusing flow paths provided between diffusion baffles positioned at the bottom of the reactor. The diffusion baffles may be prismatic shapes which are trapezoidal in cross-section with the broadest horizontal dimension at the bottom thereof. The diffusion flow paths therefore have divergent walls and act to further slow the liquid flow passing therethrough.

Abstract: An underdrain assembly for a filter tank includes a plurality of spirally shaped hollow tubular elements of substantially equal length having capped terminal ends and equally spaced perforations in lower sides thereof. The elements are equally spaced apart so that the perforations in adjacent elements are spaced substantially the same as the perforations in the tubular elements. Backwash water fed out through such perforations is therefore distributed during a backwashing operation substantially uniformly throughout the filter bed of the tank overlying the underdrain assembly so that the entirety of the filter bed is completely and uniformly backwashed.

Abstract: An apparatus for filter backwashing includes a vessel containing a bed of filter media. Laterals with nozzles are disposed below the filter media to convey backwashing air and water into the filter bed. Below the laterals are located a manifold and a distribution plenum to carry air into the laterals. The manifold and the distribution plenum are separated by a common wall having a plurality of ports to provide communication therebetween. Communication between the distribution plenum and the laterals is provided by a plurality of conduits, one conduit extending into each lateral from the distribution plenum.

Abstract: A separator suitable for the separation of a first liquid of relatively lower specific gravity and a second liquid of relatively higher specific gravity from a liquid mixture containing both liquids, the liquids being mutually immiscible, the separator comprising an inlet for introducing the mixture into a first separation zone so constructed and arranged as to promote the separation by gravity of a substantial part of the first liquid from the mixture, a first liquid outlet for the discharge of separated first liquid from the separator, a second liquid outlet for the discharge of separated second liquid from the separator, means for causing first liquid separated in the first separation zone to pass to the first liquid outlet, means for causing the remaining liquid mixture containing a minor proportion of the first liquid and a major proportion of the second liquid to pass towards the second liquid outlet along a flow path including a part extending downwardly through a second separation zone partially fille

Abstract: The filter for treatment of natural and waste water comprises a housing accommodating a body of a granular filtering material. Disposed above the filtering body is a system of troughs communicating with a collecting-distributing duct. Disposed in the lowermost bed of the filtering body is a draining-distributing system communicating with the charging or delivery duct. The charging duct is provided with a device for positive distribution of water over the length thereof.

Abstract: An upwash, upflow, graded sand filter has a reusable imperforate diaphragm on the top of the graded filter media and an inlet for pressurized fluid above the diaphragm for inflating the diaphragm against the media during filter stage. The filter housing is flared upwardly and outwardly at selected portions to reduce the velocity of upflowing liquid during wash stage for improved grading of the filter media. A natural foraminous layer may be self-grading at the top of the filter media, allowing a circumferential outlet for filtrate. A layer of fine, dense filter media may also be used to increase the size range of media particles in the filter. Special diaphragms may be composed of individual leaflets that float above a dirty-liquid outlet during wash stage, but that sink due to a change in density when the filter is pressurized for filter stage.

Abstract: A liquid distribution pipe in liquid treatment apparatus is divided into two separate liquid distribution sections. Each pipe section fits into a separate nozzle on the surface of the apparatus and is independent of the other pipe section. Each section of liquid distribution pipe can be isolated from all other sections, and can supply or withdraw liquid from the apparatus independent of the other sections.

Abstract: Water or waste water is purified by passing same through a packed layer of active carbon utilizing the absorbing activity of active carbon. An apparatus for practicing this method is disclosed.

Abstract: An apparatus for treatment of sewage and waste materials, and while applicable to larger installations, is particularly desirable for relatively small, for example family and multi-family installations, utilizing high rate bio-chemical oxidation/physio-chemical adsorption, in which the sewage is subjected to a primary biological treatment, and a secondary settling treatment, with the primary-secondary effluent, following addition thereto of an organic-inorganic chemical material comprising prereacted floc, a phosphate precipitating material and a nonionic polyelectrolyte, operative to maintain pH and zeta potential favorable to floccuation, being subjected to a tertiary treatment by passage through a mixed filtration and adsorption bed containing activated carbon, the mixed bed being periodically regenerated by a partial wet-gas oxygenation cycle, utilizing a reflex operation in which the products of regeneration are returned to the primary treatment, and in which the final effluent may, for example, contain

Abstract: An axially rigid, tubular grid is fitted over a conduit having a single longitudinal row of apertures; a fine mesh flexible tube is fitted over the grid; an end cap closes one end of the conduit and seals the tube thereto; and a tubular connection is threaded onto the other end of the conduit to seal the adjacent portion of the flexible tube to the conduit.

Abstract: A baffle and wash trough assembly is provided for reducing media loss during high-turbulence washing of granular-media filters. The assembly includes a water collection trough having an overflow weir on at least one side thereof and a lower portion with downwardly and inwardly converging sides, and a baffle supported adjacent one side of the trough; the baffle having an upwardly concave arcuate portion in opposed relation to the trough lower portion, and defining a restricted flow channel for the wash water to the trough. There may also be provided a second baffle supported adjacent the other side of the trough and having an upwardly concave arcuate portion in opposed relation to the other side of the trough lower portion. The lower end of the second baffle preferably terminates above and inwardly of the lower end of the first baffle, thereby defining a second channel for removal of backwash water.

Abstract: A process for scrubbing undissolved impurities from the upper portion of an ion exchange resin filtration bed is disclosed wherein air is introduced in the upper portion of the bed and develops a pressure within the vessel. This pressure subsequently forces rinse water down through the upper portion of the bed and out of the vessel. The gas is introduced into the bed and the water is drained therefrom at a level below the bed's upper surface but above a substantial lower portion of the resin bed. In this manner, lesser quantities of scrubbing fluids are required and the majority of the resin material is left undisturbed to maintain maximum ion exchange capacity.

Abstract: A method of filtering a liquid comprising the steps of providing a bed of particulate material, withdrawing material from the base of the bed, supplying replacement particulate material to the bed in such a manner that the bed has a free inclined upper surface, and causing the liquid to be filtered to flow through the bed by entering the same through said inclined upper suface, and apparatus for carrying out such method. Preferably the particulate material is comprised by particles of various sizes whereby a classifying action takes place to give a structured filter bed.

Abstract: There is disclosed an activated sewage disposal plant of the compact or so-called "packaged" type and a method of processing sewage wherein a fast filter is provided through which the effluent liquid from the primary processing is passed, provision being made for backwashing the fast-flow filter from time to time with the backwash being collected in a well or vessel from which it is recycled at a controlled rate to the raw sewage. The entire plant can be embodied in a compact package unit, one common type of which comprises two concentric tanks, the outer one of which is divided into several compartments.

Abstract: A filter system to follow a primary sewage treatment unit delivering substantially clarified effluent, the filter system having plural vertical filter columns nearly filled with filter aggregate and each column having a vertical stand pipe terminating near the bottom of the column and operative to introduce air to bubble up through the aggregate while the column is having water backflushed through it, and the filter system having a separate path by which backflushed water with the solids entrained therein is returned to the primary treatment unit during backflush purge cycles.

Abstract: Filtering solids from waste water liquids and cleaning, degreasing and restoring the filtering media through the use of cleaning compounds forced up through the filtering substances.

Abstract: Gas bubbles, and in particular nitrogen gas bubbles, generated during the denitrification of treated wastewater in a deep-bed filter are removed by venting them from a level below the surface of the filter bed. Gas removal may be enhanced by introducing pressurized air or water into the lower portion of the filter bed to dislodge the gas bubbles from the filter media and drive them upward where they can be vented to the atmosphere. Alternatively, pressurized air or water may be introduced into a vent pipe located below the surface of the filter bed to drive the gas bubbles up through the surface of the filter bed.