Abstract: The invention concerns an optimized method for the treatment and energetic upgrading of urban and industrial sewage sludge. It consists of a <<novel>> combination of known and tested equipment, forming a compact assembly with six functions which are: anaerobic sludge digestion (1) and biogas production, mechanical dehydration (2) up to 22-24% of dry solid, a gas turbine installation (3) burning the biogas into <<total energy>>, thermal drying (4) of the sludge up to 92% of dry solid consisting of a thin-layer dryer and a vibrated dryer/cooler with fluid bed (4b), condensation of the vapors (5) for heating the digester and the premises, and optimized energetic upgrading (6) of the dried sludge as booster fuel capable of being stored and fed into the household refuse incinerating boiler-furnaces. The method according to the invention is also applicable to the treatment and transformation of liquid manure into granulated and bagged fertilizer.

Abstract: The invention relates generally to a process and apparatus for treating biosolids resulting from the treatment of biological wastewater streams. The invention relates to autothermal aerobic treatment of biosolids where temperature is controlled by adjusting the amount of shear generated through jet aeration devices. The invention provides for a truly aerobic environment under which thermophilic microorganisms will thrive. The invention also relates to a method and apparatus for controlling foam generated in a treatment reactor.

Abstract: The improved method of converting organic wastes to valuable resources comprises a methane fermentation step (4) in which a slurry of organic waste is retained for fermentation in an anaerobic digester to thereby generate a methane-containing gas and a fermentation slurry, a hydrothermal treatment step (11) in which the fermentation slurry is subjected to a hydrothermal reaction to thereby generate a carbon slurry, and a concentrating step (14) in which an aqueous phase is separated from the carbon slurry to thereby yield a concentrated carbon slurry having a high heating value. The method is capable of performing an effective hydrothermal treatment on a slurry of low water content, prevents the slurry from putrefaction during retention in the process and it yet is capable of effective treatment of the aqueous phase of the slurry after the hydrothermal treatment.

Abstract: A wastewater treatment system is disclosed which can be used to treat high-strength septage, sewage and industrial wastewater. The wastewater treatment system consists of three major components. In the first component, solids are separated from the liquid component of the wastewater being treated. The separated solid portion is removed to a composting component wherein it is turned into a commercially useful compost material. The liquid component is subjected to a two part treatment wherein the first part of the treatment is carried out in a sequencing batch reactor and the second part is carried out in at least one reed bed. In an alternative embodiment of the present invention, the various components of the wastewater treatment system are in modular form.

Abstract: A pathogen reduction system for a sludge treatment process that employees multiple reactors operating in a batch mode to reduce pathogen levels in the sludge while providing a continuous flow of pathogen reduced sludge to a digester. In addition, the present invention entails an efficient heat exchanger for heating and cooling the sludge being treated in the above process. In particular, the heat exchanger is of the counterflow type and includes a helical coil confined in an annular chamber for transmitting one media and wherein the helical coil is spaced so as to form another helical flow channel that is defined by the annular chamber and the helical coil itself. Consequentially, one media is directed through the helical coil while another media is directed through the flow channel that is defined in part by the helical coil.

Abstract: An anaerobic process for digesting organic waste solids to produce residual solids having low levels of pathogens so as to meet regulatory Class A requirements involves a pasteurization step to reduce pathogen levels and digestion of the pasteurized material to reduce the solids volume.

Abstract: Removal of undissolved inorganic materials from an anaerobic treatment process that employs recycle or retention of anaerobic bacteria increases the efficiency of the anaerobic treatment process by removing the undissolved inorganic materials without removing substantial amounts of partially or wholly undigested organic material or anaerobic bacteria. The accumulation of inorganic materials can be minimized, thus allowing for the design of anaerobic treatment process wherein the hydrolysis of the organic materials can be maximized by focusing the reactor's design on the kinetics of the conversion of the organic material to gaseous and soluble products.

Abstract: A method of treating an organic waste water, which is capable of separating and recovering phosphorus components in a liquid or solid form, is provided. According to the method of the present invention, reuse of phosphorus components can be facilitated, while the content of phosphorus components contained in a large quantity of a primary treated liquid can be reduced.

Abstract: A process is disclosed which comprises the steps of: slurrying sludge to be treated; applying ultrasonic radiation to the slurry to decompose dioxins contained in the sludge in a reaction field developed by the application of the ultrasonic radiation and to transfer pollutants including the resulting decomposition products from a solid phase to a liquid phase of the slurry; and separating the slurry into the liquid phase containing the pollutants and the solid phase free from dioxins by solid-liquid separation means.

Abstract: The present invention relates to a device and a process for thickening and conveying waste water sludges, especially with a centrifuge. Here, the centrifuge has at least one lysis device for the breaking down of cells of organisms contained in the waste water sludges. The lysis device of the device of the invention may take the form, for example, of a friction grinder (100; 200) with grinding discs (161, 162) or a milling cone, a shaped rasp, a roller crusher, a passing drum, a cutting unit with rows of rotary cutters or a pin grinder with rows of rotating pins. The device of the invention is capable of the lysis of cells, especially those of bacteria and protozoons so that their cell content discharges into the surrounding medium which then acts as a simulation reagent for the bacteria still present in the sludge, so that on the one hand the total quantity of sludge can be greatly reduced and on the other the bio-gas yield is considerably increased.

Abstract: The present invention includes a method, an apparatus, and a system for the treatment of waste. The method includes the steps of providing a cold waste solids tank that has a cold solids batch therein. The cold solids batch is transferred, after being warmed, from the cold waste solids tank to a thermal conditioning tank for thermal conditioning. A hot waste solids tank remote from the cold waste solids tank is also provided. The cold waste solids tank is filled with a new cold solids batch. The new cold solids batch is pumped from the cold waste solids tank through a heat exchanger, the partially cooled hot waste solids batch is simultaneously pumped from the hot waste solids tank through the heat exchanger. Heat is transferred from the partially cooled hot waste solids batch to the new cold solids batch in the heat exchanger to obtain a pre-warmed solids batch and to obtain a cooled solids batch. The cooled solids batch is discharged from the hot waste solids tank.

Abstract: An apparatus and method for treating and reusing the wastewater discharged from agricultural animal farms. The apparatus and method of the present invention is designed to be a zero discharge system in which no wastewater will be discharged or spray irrigated. The wastewater effluent is first passed through a mechanical screen were bulk solids are separated and partially de-watered. The screened effluent is then directed to a primary plastic-lined earthen lagoon where it undergoes aerobic digestion utilizing specially selected bacteria. After treatment in the primary lagoon, the wastewater effluent is used to wash the floors of the hog houses or undergoes a purification phase including solids separation/denitrification, filtration and sterilization. The solids separation/denitrification phase (clarification) preferably takes place in an anoxic environment in preferably above-ground tanks where suspended solids removal will occur as well as denitrification for nitrate reduction.

Abstract: A process for the treatment of liquid hog manure which comprises adding a cellulosic material to the liquid hog manure, mixing the cellulosic material and liquid hog manure, separating said mixture to leave a solids portion and a liquid portion, drying said solids portion, and further treating said liquid portion. The methodremoves solids from the liquid hog manure and the solids may then be used for a fuel value while the liquid portion may be used as a manure or for other purposes.

Abstract: The present invention is directed to a pulsed electric-field system, apparatus and method for the effective disinfecting and dewatering previously-dewatered, biologically active waste-water sludges (e.g., municipal waste-water sewage sludge) in an efficient manner, so as to dramatically reduce the resulting volume of the inert waste material which has to be disposed of by the municipality. The method employed sequentially consists of hydraulically pressurizing the previously dewatered sludge, pre-heating the previously dewatered sludge to a predetermined temperature range, exposing the previously dewatered sludge to a high energy pulsing electrical discharges, pressure separation of the resulting solids and liquid fraction, and final pressure extrusion of the separated solids through nozzles.

Abstract: An apparatus and method for treating waste water to generate clarified water for reuse in industrial processes which includes the steps of adding agents to the waste stream to generate floccules, aerating the waste stream to cause a portion of the floccules to float, decanting floating floccules and lighter than water immiscible pollutants from the top surface of the waste stream, directing the waste stream through an incline clarifier so as to permit heavier than water floccules to form sludge in a bottom region of the clarifier. Sludge and decanted pollutants are sent to a bioremediation tank where hydrocarbons are decomposed and the remaining sludge is dewatered and compacted to a solid condition for disposal in a public waste facility. The clarified water is transferred to a steam generator or pressurized water delivery system for reuse. The invention is particularly useful for equipment cleaning operations such as in truckyards or airports.

Abstract: The present invention comprises a wastewater treatment process wherein the waste activated sludge is digested to produce treated biosolids which are then directed to a dewatering facility that removes water from the treated biosolids. Before or during the dewatering process, both a low molecular weight polymer and a high molecular weight polymer are added to the treated biosolids. The addition of the two polymers of different molecular weights results in the treated biosolids coagulating and then forming flocs of biosolids that effectively drives water from the flocs and renders the flocs more susceptible to an efficient and effective dewatering process.

Abstract: A reusable immobilized microbial composition is formulated. The formulated microbial composition comprises a synergistic mixture of the bacterial strains of Enterobacter cloaca, Citrobacter amalonaticus, Pseudomonas aeruginosa,Yersinia enterocolitica, Klebsiella oxytoca, Enterobacter sakazaki and Serratia liquefaciens. The formulated microbial composition is immobilized on an appropriate immobilizing agent to form beads. The said beads are tested as microbial seeding material for BOD analysis using Glucose Glutamic Acid (GGA) as a reference standard. The obtained BOD values by the formulated beads are compared with BOD values obtained by sewage as seeding material using synthetic samples as well as industrial effluents. The formulated microbial beads are ready-to-use as well as reusable seeding material in BOD analysis. The said beads can be reused up to five times with same efficacy.

Abstract: The invention relates generally to a process and apparatus for treating biosolids resulting from the treatment of biological wastewater streams. The invention relates to autothermal aerobic treatment of biosolids where temperature is controlled by adjusting the amount of shear generated through jet aeration devices. The invention provides for a truly aerobic environment under which thermophilic microorganisms will thrive.

Abstract: Method of continuous treatment and purification of biologically decomposable waste and liquid in a rotatably elongated perforated cylinder longitudinally divided into a dewatering and wet composting unit, a central dewatering unit and a dry composting unit. The perforated cylinder is surrounded by an envelope for collecting liquid wastes which are treated by oxygenated filter units in communication with the envelope structure. The device also includes a hollow perforated shaft within the cylinder for supplying oxygen to the interior of the cylinder and for rotating the cylinder.

Abstract: A chemical method is provided for the dewatering of biological sludge that has been digested by a thermophilic digestion process. Five versions of the chemical sludge dewatering method are presented. The primary component in the five versions is a polyquaternary amine, preferably of the di-allyl di-methyl ammonium chloride (DADMAC) variety and from the epichlorohydrin di-methyl amine (epi-DMA) variety. By the first sludge dewatering method, the polyquaternary amine is added directly, along with a polyacrylamide, to the biological sludge. By the second sludge dewatering method, the polyquaternary amine and an anionic polyacrylamide are added separately. By the third sludge dewatering method, a quaternized polyacrylamide, having the polyquaternary amine as part of its polymer chain, is produced by copolymerization of acrylamide with monomers of polyquaternary amine quaternization and is added individually to the sludge.

Abstract: A method is described for the continuous disintegration of microbial sludge in a sewage clarification or sewage treatment plant wherein the microbial sludge is decomposed biologically by bacteria and the resultant sludge (5) is exposed to sonic radiation in a treatment vessel (1) in order to split the cell walls of the microorganisms. With that, the sonic radiation shall be generated asymmetrically in the treatment vessel (1). The intensity of the sonic exposure lies-in an area of 500 to 1500 W/m2 and the sludge (5) is fed with a mean dwell-time of 2 to 4 minutes in counter-flow through the treatment vessel (1). The device for carrying out the method possesses a treatment vessel (1) with an eccentrically arranged sonic resonator arranged within (7).

Abstract: The present invention is directed to a pulsed electric-field system, apparatus and method for the effective disinfecting and dewatering previously-dewatered, biologically active waste-water sludges (e.g., municipal waste-water sewage sludge) in an efficient manner, so as to dramatically reduce the resulting volume of the inert waste material which has to be disposed of by the municipality. The method employed sequentially consists of hydraulically pressurizing the previously dewatered sludge, pre-heating the previously dewatered sludge to a predetermined temperature range, exposing the previously dewatered sludge to a high energy pulsing electrical discharges, pressure separation of the resulting solids and liquid fraction, and final pressure extrusion of the separated solids through nozzles.

Abstract: Hydrolyzing organic waste material in a multi-stage reactor comprising a heated first stage, a further heated second stage, a still further heated third stage, and a fourth stage, with a valved exit way connected to the fourth stage and a valve entryway connected to the first stage.

Abstract: The invention relates to a process for the stabilization of sludge or other waste with a high organic matter content derived from treatment operations of industrial and/or urban effluent, or from drinking water treatment operations of surface or ground water, said sludge containing at least one part dry matter essentially made up of fermentable organic matter, characterized in that it is conducted at ambient temperature and atmospheric pressure, and in that it comprises a stage consisting of acidifying said sludge with at least one strong acid to a pH of between 1.5 and 3.5, a stage consisting of adding at least one nitrite salt to said sludge at a concentration of between 10 and 500 mg N.NO.sub.2 /l sludge, and in that it consists of maintaining the mixture made up of said sludge, said acid and said nitrite salt in contact for a period of between 5 minutes and 12 hours, under permanent or intermittent mixing.

Abstract: A method and apparatus for wastewater treatment is provided which can prevent any decrease in permeation efficiency of a submerged membrane without involving an increase in operating cost and sludge generation, and which can treat high concentration organic wastewater efficiently and without dilution. The wastewater treatment method has the steps of: concentrating domestic sludge by means of a first submerged membrane to produce thick sludge; mixing the thick sludge into a water to be treated, and introducing the water to be treated which is so mixed with the thick sludge into an anaerobic treatment portion for anaerobically treating the same; and introducing the anaerobically treated water from the anaerobic treatment portion into an aerobic treatment portion having a second submerged membrane disposed therein to subject the water to aerobic treatment.

Abstract: The method of treating wastewater or bioorganic sludges containing odor, animal viruses, pathogenic bacteria, and parasites to produce a bioactive but stabilized product that is useful as a soil substitute or as a fertilizer which can be applied directly to lands which consists essentially of the following steps: mixing said sludge with at least one alkaline material, wherein the amount of added material mixed with said sludge is sufficient to raise the pH of said mixture to pH 12, and raise the conductivity to disinfect and stabilize the sludge, and adding green waste at different process locations so that a biological action occurs converting the greenwaste into a soil-like granular product with improved odor over that of the treated municipal sludge alone or a composted greenwaste alone.

Abstract: A method of treating sludge to provide a stable product for use as a beneficial soil or fertilize for agricultural lands is disclosed which includes the steps of:(a) mixing sludge with at least one alkaline material in an amount sufficient to raise pH of the mixture to a level of at least 12 and to increase percent of solids in the mixture to at least 40% by weight, and such that odorant sludge organics and inorganics are bound to adsorbent particles of the alkaline material,(b) aerating and drying the mixture by agitation and heating to stabilize the mixture and increase the percent solids to at least 50% by weight, and(c) pasteurizing the dried mixture at a temperature at or above 52.degree. C.

Abstract: A method for treating wastewater is useful in treatment of biomass (sludge) resulting from wastewater treatment, particularly for biological sludges of aerobic, facultative and/or anaerobic origin. The invention relates fractionation of microorganisms and organic materials within the sludge by mechanical shearing, in combination with heat, chemical and/or biochemical treatment to improve waste treatment and to release nutrients for recirculation for use by microorganisms in the waste treatment system.

Abstract: A chemical method is provided for the dewatering of biological sludge that has been digested by a thermophilic digestion process. Four versions of the chemical method are presented. The primary component in the four versions is a polyquaternary amine, preferably of the di-allyl di-methyl ammonium chloride (DADMAC) variety and from the epichlorohydrin di-methyl amine (epi-DMA) variety. By the first method, the polyquaternary amine is added directly, along with a cationic polyacrylamide, to the biological sludge. By the second method, the polyquaternary amine and an anionic polyacrylamide are added separately. By the third method, a quaternized polyacrylamide, having the polyquaternary amine as part of its polymer chain, is produced by copolymerization of acrylamide with monomers of polyquaternary amine quaternization and is added individually to the sludge. By the fourth method, the quaternized polyacrylamide from method three is added in concert with a cationic polyacrylamide to the sludge.

Abstract: A waste decomposition system, having a container and an air circulation system integrated into the container. The air circulation system has a positive air pressure source; and a negative air pressure source. Also a method for decomposition of liquid and solid organic waste, including the steps of: (a) providing a container for collecting the waste; (b) forcing air through the waste with a positive air pressure source; (c) withdrawing air from the container with a negative air pressure source.

Abstract: A first reaction/adjustment tank has a lower portion containing a calcium carbonate mineral, an upper portion containing a calcium carbonate mineral and a plastic filler, and an air lift pump for circulating waste water from the lower portion to the upper portion. Exhaust gas is introduced into a space. A second reaction/adjustment tank has a lower portion containing a calcium carbonate mineral and charcoal, and an upper portion containing charcoal and a plastic filler. Waste water circulates sequentially through the lower and upper portions of the first reaction/adjustment tank, and the lower and upper portions of the second reaction/adjustment tank. Exhaust gas circulates sequentially through the upper portion of the first reaction/adjustment tank and the upper portion of the second reaction/adjustment tank.

Abstract: A compact and energy efficient photosynthetic filter for purifying and conditioning aquarium water comprising a receptacle (108) for holding aquarium water, a growth element (202) having a growth surface (204) of sufficient texture for growing adherent photosynthetic organisms, and a non-continuous illumination device for providing photosynthetic-sufficient illumination to the photosynthetic organisms. A non-continuous illumination device in accordance with a preferred embodiment of the invention comprising a continuous light source mounted over a submerged, rotatably mounted, elongated, and substantially cylindrical growth element (202). Rotation of growth element (202) under the light source providing non-continuous illumination to adhered photosynthetic organisms. Rotation of the growth element is preferably powered by a motor (212) or turbine (600).

Abstract: A sludge dehydrating agent which is excellent in storage stability and prevented from becoming water-insoluble during storage and hence can be distributed in the market securely by solving the problem of the conventional dehydrating agents comprising amphoteric polymers that they undergo deterioration and become water-insoluble when stored for long, thus becoming substantially unusable. This dehydrating agent comprises a copolymer composed of cationic vinyl monomer units, vinylic carboxylic acid monomer units and nonionic vinyl monomer units and a salt of a group IIA metal of the periodic table. Preferable examples of the vinylic carboxylic acid monomer include acrylic, methacrylic and crotonic acids, while those of the nonionic vinyl monomer include acrylamide and methacrylamide. The metal salts usable herein include those of mineral acids and organic carboxylic acids, and preferable mineral acid salts include calcium chloride, magnesium chloride and magnesium sulfate.

Abstract: A method of anaerobic digestion of sewage sludge including the steps of subjecting surplus sludge to preliminary heat treatment at 60.degree. C. or higher, dewatering the surplus sludge to make dewatered sludge of 10 to 25% by weight, mixing the dewatered sludge with digested sludge which is taken out from a methane fermentation vessel of dewatered sludge, and supplying the resulting mixture to the methane fermentation vessel of dewatered sludge while discarding digested sludge whose amount is equal to that of the dewatered sludge supplied. According to the method, the sewage sludge containing a large quantity of surplus sludge is subjected to preliminary heat treatment, and then the heat-treated sludge is dewatered to permit a nitrogenous component to be transferred to eliminated water whereby the nitrogenous component in the dewatered sludge can be reduced. The resulting dewatered sludge can stably undergo methane fermentation even at a high concentration of 10 to 25% by weight.

Abstract: The present invention is directed to a pulsed electric-field system, apparatus and method for the effective disinfecting and dewatering previously-dewatered, biologically active waste-water sludges (e.g., municipal waste-water sewage sludge) in an efficient manner, so as to dramatically reduce the resulting volume of the inert waste material which has to be disposed of by the municipality. The method employed sequentially consists of hydraulically pressurizing the previously dewatered sludge, pre-heating the previously dewatered sludge to a predetermined temperature range, exposing the previously dewatered sludge to a high energy pulsing electrical discharges, pressure separation of the resulting solids and liquid fraction, and final pressure extrusion of the separated solids through nozzles.

Abstract: A process for treating a waste sludge of biological solids including the steps of mixing the sludge with an oxide-containing chemical and sulfamic acid so as to elevate a temperature of the sludge, pressurizing the mixed sludge to a pressure of greater than 14.7 p.s.i.a., and discharging the pressurized mixed sludge. The oxide-containing chemical can be either calcium oxide, potassium oxide, or potassium hydroxide. The sludge has a water content of between 5 and 85 percent. The oxide-containing chemical and the acid are reacted with the sludge so as to elevate the temperature of the sludge to between 50.degree. C. and 450.degree. C. The pressurized mixed sludge is flashed across a restricting orifice or passed into a chamber having a lower pressure. The evaporated liquid component can be condensed and used as part of the process. The oxide-containing chemical is mixed with the sludge in an amount between 5 and 50 weight percent of the sludge.

Abstract: A method and an apparatus for producing plant nutritive pellets from raw sludge produced by wastewater treatment plants. The raw sludge has a water content normally in the region of 70-80%. Powder is used to stabilize the pellets and prevent their sticking together. The powder is added in connection with the sludge being formed into at least one pellet string or immediately after formation when the string has been cut into pellets. An air stream in which the powder has become entrained is used to douse the pellet string or the cut-off pellets, whereafter drying is readily peformed to provide a moisture content of about 10-15%, adequate for storage. The device according to the invention comprises an extruder for forming at least one pellet string, which by cutting-off means is cut into separate pellets, at least one blowing nozzle for lime powder intended to be doused over the pellets, a rotatable tumbler and a drying kiln, in which the pellets are dried to a moisture content adequate for storage.

Abstract: In a process for dehydration and concentration of sewage sludge containing activated sludge with the aid of organic and/or inorganic flocculators, the activated sludge content is produced in an aerated biological purification stage in presence of a composition containinga) folic acid and/or dihydrofolic acid or at least one ammonium, alkali metal, alkaline earth metal and/or alkanolammonium salt thereof andb) a water-soluble molybdenum compound,whereby an improved sludge dehydration of the activated sludge content is achieved.

Abstract: Dry, free flowing solids, suitable for handling, transportation and/or disposal are produced from messy biologically treated sludges. In the process, the sludge feed is pressurized and heated, then flashed, in order to vaporize a portion of the water; the residual liquid, containing the solids and sometimes heavy metals, is contacted with a chelating agent, if needed, and a flocculating agent over a brief reaction period in order to precipitate a concentrated solid precipitate; and the precipitate is separated from the residual liquid water.

Abstract: A starting mixture of liquid and solid organic wastes that is susceptible to at least partial microbiological degradation, with formation of biogas, is treated by the following process. The mixture is mechanically separated into a first sludge phase with enriched dry substance and a first liquid phase containing dilute solids. The first liquid phase is subjected to anaerobic treatment leading to formation of biogas and to the development of a second sludge phase and a second liquid phase. The first sludge phase is subjected to aerobic treatment resulting in the formation of compost, fertilizer, or feed. At least part of the second sludge phase is recirculated into the starting mixture, thereby causing the formation of biogas in the starting mixture and facilitating decomposition of higher compounds contained in the starting mixture.

Abstract: There is disclosed a fermentation device having a peripherally extending wall, a gas-impermeable cover extending over the surface of the device, and attached at its peripheral edge to a top part of the wall, and a gas collection conduit extending for at least part of the periphery of the device within the wall. This device may be used for wastewater treatment enclosures.

Abstract: An apparatus for waste water treatment, wherein fluorine contained in waste water is treated into a fluoride through a chemical reaction and sludge containing the fluoride is thickened and dehydrated into a sludge cake, has first and second tanks each packed with calcium carbonate mineral. In the first tank, waster water containing fluorine is agitated by air discharged from an air diffuser and caused to react with the calcium carbonate mineral. Through this reaction of the waste water with the calcium carbonate mineral and action of microorganisms on the surface of the calcium carbonate mineral, a pH value and a fluorine concentration of the waste water is adjusted till the pH value and the fluorine concentration fall within their respective predetermined ranges.

Abstract: Secondary sludge produced in the papermaking process is dewatered by adding a material capable of absorbing water together with dry fibers to the secondary sludge, and mixing the secondary sludge with the dried fibers to produce a modified secondary sludge which has sufficient structure and low enough moisture that it may be further dewatered by mechanical means. The preferred fiber adding materials are those readily produced in the papermaking process, particularly dry primary sludge, dried fines and bark and fly ash from boilers.

Abstract: A drying bed for waste sludge in a wastewater treatment facility having a vertical drainage riser extending vertically from a subnatant discharge pipe near the bottom of the drying bed. A sludge inlet at an end of the drying bed communicates with a source of watery sludge. Water communicates through a mesh screen that wraps the vertical drainage riser and through openings in the vertical drainage riser to the subnatant discharge pipe. A valve is selectively opened to control the flow rate of the water from the subnatant discharge pipe. A method of dewatering waste sludge is disclosed.

Abstract: A dehydration treatment apparatus for sludge wherein organic sludge and a modifying/setting agent are charged into a rotating drum and the sludge is dehydrated and dried. The apparatus comprises a rotating drum, a sludge charging hopper arranged on the inlet side of said rotating drum, a discharging screw arranged on the outlet side of the rotating drum, at least two rectangular blades that are projected from each of circular surfaces arranged toward the feeding direction from the inlet side of the inner circumferential surface of the rotating drum and are slanted downward at a prescribed angle toward the feeding direction, and an agitating/feeding means wherein the positions of the blades on the circular surfaces are made different stepwise successively in the direction of rotation toward the feeding direction so that sludge may be scraped up by the blades on the fore circular surface to be fed forward.

Abstract: An anaerobic digestion process for sewage sludge comprises the steps of dewatering raw sewage sludge to provide a solids content therein in the range of 10 to 25 weight %, recirculating a portion of digested sludge resulting from methane fermentation and having a dry solids content lower than that of said dewatered raw sewage sludge, adding one part by weight of the dewatered raw sewage sludge to at least one part by weight of the recirculated digested sludge, homogeneously kneading the resulting mixture for inoculation, and causing methane fermentation of the inoculated sludge mixture in a tube-shaped digestor. The inoculated sludge is moved in the longitudinal direction of the tube in the digestor during methane fermentation, and a portion of the sludge discharged from the digestor is recirculated.

Abstract: A process for the production of a durable granular or pelletized sludge product is disclosed whereby a minimal amount of high calcium oxide material is utilized for pathogenic stabilization, a portion of the resulting hot mixture being recycled back to the mixing stage to reduce the requisite lime consumption by utilizing unreacted lime, for energy recovery and to increase dryness.

Abstract: In order to considerably reduce expenditures for the dewatering of sludges, particularly from sewage treatment facilities, and thereby perform the step from a sticky, wet solid to a flowable solid granulate practically without the re-admixture of material, it is proposed to employ a solid bowl sludge centrifuge as the dispersing member in a subsequently connected convection dryer for further dewatering of the wet solids particles that are ejected with a dry substance content of approximately 25-35 weight percent. The wet solids particles that are ejected at high speed in the form of a film of particles from the outlet of the solid bowl sludge centrifuge are surrounded by the hot drying gas while still on their trajectory and are pre-dried to a dry substance content of approximately 65 weight percent (FIG. 5).

Abstract: A method for treating bioorganic or raw or treated wastewater sludge so that a stability based upon achieving a significant microbial population, conductivity level and percent solids, is developed rapidly, is provided for indefinitely and is independent of climatic conditions. A dewatered sludge that has not been treated (i.e., raw) or a sludge that has been treated to a PSRP level or a sludge that has been treated to a PFRP level, i.e., pasteurized or sterilized sludge when still in a wet condition, i.e., between 12%-30% solids, or when in a dry condition, i.e., between 30-60% solids, is mixed with alkaline adsorptive materials to reduce odor, to increase the percent solids and to facilitate granulation, is adjusted to a mildly alkaline pH, and is adjusted to an ionic conductivity which will allow the sludge to mature rapidly when seeded with a beneficiating microbial flora. This process will reduce the pH or a high alkaline treated sludge, e.g., often above pH 12, to a physiological pH of between 7 and 9.

Abstract: A sludge dehydrating press includes a container in which sludge to be treated is filled, a press unit for pressing sludge filled in the container, one or more screen cases disposed at positions in the container where water can be extracted from the sludge in substantially all portions of the sludge pressed by the press unit. Each of the screen cases has a screen surface extending parallel to the direction of pressing by the press unit and has also a space into which water extracted from the sludge flows. By driving the press unit, sludge in the container is compressed and extracted water is caused to flow into the space in the screen cases and is drained to the outside of the dehydrating press.