Abstract: A method of a wastewater treatment in a system consisting of at least one acid consuming step and at least one volatile acid generating step and further comprising step of evacuating the volatile acid from that at least one step generating at least one volatile acid and step of transferring at least one volatile acid to that at least one acid consuming step.

Abstract: This metal containing waste water treatment method introduces a metal containing waste water from above into a submerged membrane separation tank 1 in which a reaction section 2, a submerged membrane section 3 having a submerged membrane 5 and a precipitation section 4 are arranged in order from top to bottom, causes a reaction by adding a pH adjuster to the reaction section 2, subsequently separates water from metal by the submerged membrane 5 of the submerged membrane section 3 and subsequently precipitates and concentrates the metal in the precipitation section 4. As described above, according to this treatment method, the pH adjuster is added to the reaction section 2, and therefore, solid-liquid separation can be effected by the submerged membrane 5 with a hydroxide formed. Moreover, the metal can be precipitated and concentrated by the action of gravity without using energy in the precipitation section 4.

Abstract: A process for destroying pathogens in sludges/biosolids using rotor-stator technology to produce cavitation for pathogen destruction, combined with the feeding of lime or other alkaline material to induce heat and ammonia gas release. The combination of the rotor-stator with the lime produces higher temperatures than the addition of lime alone with a very high mixing efficiency giving maximum pH shift and ammonia release to all portions of the matrix. Overall, the process destroys the resistant stages of helminths or protozoan pathogens through a combination of cavitation with the increased heat caused by the rotor-stator/lime process, along with the locally released ammonia induced by the pH shift.

Abstract: The invention relates to a hybrid biological and chemical method for decontaminating sludge containing heavy metals and pathogenic microorganisms, consisting of the following steps: the sludge is mixed with an acidic leaching solution in order to acidify the sludge with a pH which is low enough to solubilize the majority of the heavy metals and to destroy most of the pathogenic microorganisms but which is also high enough to minimize the solubilization of fertilizing elements; oxidation-reduction of more than +400 mv is maintained, liquid-solid separation occurs in order to obtain a solid fraction comprising decontaminated acidic sludge and a liquid fraction comprising heavy metals which are dissolved in a leaching solution; the sludge is neutralized: and neturalized decontaminated sludge is recovered, whereby the fertilizing elements contained therein, i.e. carbon, nitrogen and phosphorus, remain substantially unchanged in relation to the initially contaminated sludge.

Abstract: A method and biological cleaning system are provided for cleaning substrate surfaces of oils and/or greases using a biological cleaning system which utilizes a pre-treatment bath and/or post-treatment bath as part of the cleaning system. The pre-treatment and/or post-treatment baths are compatible with the biological cleaning bath and during operation of the system, the used pre-treatment and/or post-treatment baths are recycled to the biological cleaning solution for biodegradation. A system is provided in which none of the pre-treatment, post-treatment or biological cleaning baths need expensive waste disposal. Replenishment pre-treatment and/or post-treatment baths as well as biological cleaning baths are added as needed to the biological cleaning system. Other treatment baths may be added directly to the biological cleaning bath with or without pre-or post-treatment for specific purposes such as a detergent phosphating bath used in the biological cleaning tank to provide a cleaned phosphated part.

Abstract: In the waste water treatment apparatus, organic matter-containing fluorine waste water is treated in a reaction tank into which biological sludge and calcium-containing chemical sludge are introduced, thus making it possible to treat organic matters in the waste water by microorganisms contained in the biological sludge, and simultaneously to treat fluorine in the waste water by the calcium-containing chemical sludge. Therefore, since organic matters in the waste water and fluorine in the waste water, which differ in chemical properties from each other, can be treated with one reaction tank, it is no longer necessary to provide two reaction tanks, thus allowing the initial cost to be reduced. That is, this waste water treatment apparatus is capable of reducing the quantity of waste materials and reducing both initial cost and running cost.

Abstract: The invention uses the electro-kinetic principle for a method for the cleaning of materials contaminated with heavy metals, whereby use is made of an apparatus comprising two charge-selective ion-exchange membranes with different charges combined with an inner and an outer electrolyte solution chambers which are separated by the membranes which serve a blocking function. A surprisingly good degree of removal is achieved, particularly in relation to the current consumption, and at the same time the heavy metals can be precipitated in a separate vessel such that they can be reused.

Abstract: Disclosed is a method for treating groundwater, or other water streams contaminated with oxygenate(s), particularly MTBE and TBA, characterized by improved biodegradation of MTBE, the biodegradation of TBA, and reduced frequency of the need to change the carbon bed, which comprises inoculating a biodegrader capable of degrading said oxygenate on an activated carbon bed through a rigid tubular instrument having a plurality of holes around the circumference of the end used for inoculation of the carbon bed by a method that optimizes dispersion and colonization; and flowing said groundwater, or other water stream contaminated with said oxygenate through a structure having a top, bottom and sides and a predetermined volume containing said bed of activated carbon having said biodegrader inoculated thereon. The invention is also an apparatus for biodegradation of oxygenate(s).

Abstract: Bioremediation of waste water traveling through a sewer system is accomplished by suspending in selected manholes a self-powered feeder device for delivering a desired amount of a solid microbial wastewater treatment preparation. The feeder device is preferably a) sealed to prevent moisture from causing caking or clumping of the solid microbial treatment preparation, b) controlled by a programable microprocessor and c) powered by a self-contained battery pack that allows the device to function for a desired period of time without maintenance or manual handling.

Abstract: This invention pertains generally to anaerobic digesters, and more particularly to a system and process that extends the range of acceptable biomass feedstock concentrations and provides pH process control of all known digestion processes: by the creation of a vacuum or vacuum retort in or before the digester that essentially acts to boil off excess liquid, thickening the liquor of the digester to an optimum value; and to control the pH of the various phases or stages of digestion by separating the component products of digestion and mixing or diffusing a portion of said component products into the mixing system of each phase of the process. A system and process: that produces a potable water effluent, clean commercially useful by-products, zero environmental emissions, a very positive ecological impact; and, that has the capability of being completely self powered plus providing energy back to the community or industry that supports or owns it.

Abstract: A calcium carbonate mineral is placed in a lower portion of a second water tank, while sludge precipitated in a sixth water tank is returned to an upper portion. A blower and an air diffusion pipe weakly aerate the lower portion. Thus, an unreacted chemical sludge zone is formed in the upper portion of the second water tank. As a result, the second water tank can execute a primary treatment of fluorine in a waste water by the calcium carbonate mineral, a secondary treatment of fluorine and a primary treatment of phosphor by unreacted chemicals, treatment of surface active agent by microorganisms in a return sludge and reduction treatment of hydrogen peroxide by anaerobic microorganisms in the return sludge. The unreacted chemicals are thus reused, so that the amount of generation of waste can be reduced and concurrently the treatment can be executed with energy conservation.

Abstract: The present invention relates to a method and a system for mechanical biological waste treatment, the waste being first homogenized, comminuted and moistened thoroughly and being then biologically treated in an aerobic rotting assembly ventilated by means of the chimney-draft method.

Abstract: The invention relates to a process for preparing a fermentation medium for producing high-purity metabolites from a renewable raw material, characterised in that it consists of optionally treating said renewable raw material to enrich it with carbon or nitrogen sources which can be directly assimilated by micro-organisms and to eliminate insoluble impurities, using a technique chosen from the group consisting of nanofiltration and electrodialysis, alone or in combination, to eliminate low molecular weight impurities from said renewable raw material without degrading its concentration of carbon sources which can be directly assimilated, treating the raw material from which the low molecular weight impurities have been eliminated in this way to top it up with nitrogen or carbon sources which can be directly assimilated by the micro-organisms, and recovering the fermentation medium obtained in this way.

Abstract: A process for treating contaminated liquid, in which the liquid to be treated is contacted with a charged polymeric material and with a second, oppositely charged polymeric material. The polymeric materials are soluble in the liquid, and at least one of the soluble polymeric materials is a branched polymeric material. Floc formation is allowed and the flocs are separated from the liquid. The first and second polymeric materials may be selected from the group consisting of polysaccharides, proteins, lipids and polyhydroxy alcohols.

Abstract: A process for treating sludge comprising the addition of sulphuric acid and anhydrous ammonium to the sludge inside a granulator in order to produce an exothermic reaction which generates sufficient heat to evaporate the water contained in the sludge, thus eliminating all the pathogen and non pathogen microorganism, and producing a dry product having a low pH, free of polluting agents and a high commercial value.

Abstract: The invention relates to a method for decoloring liquids, in particular ground water, by means of a membrane filtration unit, wherein the following steps are carried out: i) subjecting the ground water to a biological treatment in a bioreactor; ii) feeding the effluent from the bioreactor of step i) to the membrane filtration unit, in which membrane filtration unit a separation between biomass and decolored ground water takes place; followed by iii) feeding back the biomass from step ii) to the bioreactor. The invention also relates to decolored ground water and to a device for decoloring liquids.

Abstract: The invention relates to a method for biologically treating a fluid sufficiently charged with organic materials, the method being performed in a tank and the fluid being: first subjected to a mixing and acidifying step (A), subsequently in a heavy load step (B) during which activated-sludge is re-circulated and then in a light load step (C) subjected to anaerobic degradation whilst producing methane gas, and subsequently treated in a secondary sedimentation step (D) from where the sludge can also be re-circulated, and the biogas which is produced in the heavy load step (B) and the light load step (C) is collected.

Abstract: The preferred embodiments provide for a family of novel compositions to serve as substrates that release hydroxy acid slowly over time. Preferably the hydroxy acid is an &agr;-hydroxy acid, more preferably it is lactic acid. The compositions are preferably made by reaction of poly(lactic acid) with multifunctional alcohols. Also disclosed are formulations based on the compounds and methods of use for both the compositions and the formulations. The preferred use of the compositions and formulations is for bioremediation purposes wherein they provide a time-release source of lactic acid to support the growth and reductive activity of microbes present in a system or medium, such as an aquifer, bioreactor, soil, industrial process, wastestream, body of water, river or well. The microbes destroy or inactivate compounds which are capable of being reduced, such as nitrogen-containing organic compounds, oxygen-containing organic compounds, polyaromatic hydrocarbons, and halogen-containing organic compounds.

Abstract: The invention relates to a method and installation for treating waste water from oil seed and cereal processing, especially olive oil mill waste water (OMW), guaranteeing a substantial reduction of environmentally damaging waste water ingredients while taking economic factors into account. The aim of the invention is to develop a method and system designed to treat olive oil mill waste water, whereby higher physical, chemical, biochemical and biological elimination rates can be achieved using the material and energy potential of the OMW while taking economic aspects into account. The installation needs to be able to operate at short notice due to the amounts of seasonal waste. In the inventive method and installation thus disclosed, the fresh waste water is pre-treated by subjecting it to acidification with biogenic flocculation and separation of solid particles.

Abstract: A system is disclosed comprising a first anaerobic digester, an ammonia recovery vessel, and a second anaerobic digester. Microorganisms within the first anaerobic digester are primarily hydrolyzers and acetogens, and microorganisms within the second anaerobic digester are primarily methanogens. A nitrogen containing feed stock is passed to the first digester in which the feed stock is treated to accomplish hydrolysis and acetogenesis. An effluent stream from the first digester is passed to the ammonia recovery vessel in which ammonia is removed to generate a low ammonia effluent stream. The low ammonia effluent stream is then passed to the second digester in which it is treated to accomplish methanogenesis, thereby generating a biogas.

Abstract: This invention provides a compact effluent water reclamation apparatus which is minimized in the kinds and amounts of chemicals to be used for the recovery of water to thereby reduce the amount of waste and eliminate equipment which necessitates a large area for installation. The effluent water reclamation apparatus comprises a reverse osmosis device and is adapted to treat acid-alkali effluent water containing organic matter but no fluorine, by concentrating the acid-alkali effluent water containing organic matter by reverse osmosis, evaporating the resulting concentrated water to dryness and collecting the water permeating through a reverse osmosis membrane.

Abstract: The present invention relates to a process for utilizing waste waters which comprises the separate collection of gray water and/or black water and membrane filtration of the separately collected gray water and/or solids/liquid separation of the separately collected black water. The present invention preferably relates to a process for producing potable water from gray water or one or more of its partial streams. Moreover, an apparatus for producing potable water from gray water and an apparatus for utilizing black water and its use is described.

Abstract: The invention concerns a method for treating water to abate their content in suspended matter and, as the case may be in parasites, characterised in that it consists in causing said water to pass through at least one sedimentation tank (1) at a treatment speed higher than 20 mph then, through at least a multilayer filter with decreasing size grading (2) at a treatment speed higher than 10 mph. The sedimentation tank used is preferably a sedimentation tank with ballasted floc preferably lamellar.

Abstract: A wastewater absorption field reclamation and maintenance system, wherein effluent (wastewater) is oxygenated such that BOD is not reduced in the effluent, the oxygenated effluent being delivered to the absorption field. As the oxygenated effluent flows to the absorption field, the enhanced oxygen enables aerobic decomposition of organic matter which has reduced the infiltrative capacity of the absorption field.

Abstract: A process for treating water to reduce pollutants using a fluidized bed (41) supporting microorganisms, ozonated pollutants and a carbon source for the microorganisms is described. The process provides very efficient degradation of the pollutants in drinking water, for instance.

Abstract: A method for denitrification of water, in which the water to be denitrified is made to flow over a porous carrier which comprises a transition metal, preferably palladium, used in an amount between 0.01 and 5% by weight on the carrier and on which denitrifying bacterial strains capable of surviving in the presence of hydrogen are made to adhere, and in which hydrogen is used as a reducing agent and the pH of the reaction is adjusted to values of 4.5 to 7.8 preferably by using carbon dioxide.

Abstract: A process is provided to create a treated recycle stream through pre-treatment and solids separation for reuse in animal feeding operations without odors and creates a treated liquid effluent that can be stored for reuse, or can be land applied without odors and is free from pathogens and nutrients. Additionally the methods describe a means of converting animal manure to organic fertilizer and removing nutrients from the liquids to create a feed supplement from biomass. The organic fertilizer is non-leaching and free from pathogens. The entire process is accomplished in a reduced footprint from other treatment processes and allows waste ponds to be removed from service.

Abstract: An aqueous stream such as pulp mill condensate containing one or more sulfur compounds is treated by (a) reacting an aqueous feed stream containing TRS contaminant selected from the group consisting of hydrogen sulfide, methyl mercaptan, dimethyl sulfide, dimethyl disulfide, and mixtures thereof, with ozone to produce a first liquid product stream and a first gaseous product stream, wherein the total amount of said one or more contaminants in said first liquid product stream is less than 1% of the amount thereof in said feed stream, and wherein said first gaseous product stream contains ozone and one or more of said contaminants; and (b) treating said first gaseous product stream with an alkaline aqueous stream to remove essentially all of said one or more contaminants from said first gaseous product stream. Preferably, a second gaseous stream produced in step (b) and containing ozone is reacted with an aqueous stream containing one or more of said contaminants, to consume all the ozone in said stream.

Abstract: An Intermittently Decanted Extended Aeration (IDEA) process characterized in that an aeration period, a settling period and a decanting period are successively repeated in that order in a single reactor, and influent wastewater is transversely supplied at the bottom of the reactor and slowly diffused in the reactor while treated wastewater wich is intermittently discharged during the decanting period is provided. According to the process of the invention, wastewater can be efficiently treated without by-pass of wastewater under dry weather and wet weather conditions as well as stormy weather condition.

Abstract: A method for recovering phosphate from sludge includes the processes of treating sludge drawn from a water treatment system at a sewage treatment plant in an anaerobic condition to release polyphosphate accumulated in the sludge into solution, and recovering phosphate in the solution using a seed crystal material.

Abstract: An apparatus for treating a secondary treated wastewater effluent. The apparatus comprises an anoxic first zone for accepting the secondary effluent wherein the first zone includes heterotrophic bacteria, a carbon source, and an outlet structure including a limestone aggregate. The apparatus further comprises a second zone including an entrance structure that is in fluid communication with the outlet structure and an exit structure in fluid communication with the second zone. The exit structure includes a cationic exchange medium wherein the exit structure discharges the effluent to a disposal mechanism such as a subsurface disposal field.

Abstract: Sewage waste digestive bacteria and enzymes are incorporated into a slow release material and delivered to the site of the waste to digest the solid waste. The slow release material is made heavy so the enzymes and bacteria will be delivered to the sludge in the bottom of a sewage digester chamber and made fat soluble so that the enzymes and bacteria will be delivered to the grease in the waste system to be digested. This selective delivery system prevents the enzymes and bacteria from being diluted in grey water rendering them less effective and discharged from the sewage system without digesting waste.

Abstract: A process for treating waste water containing a resin is disclosed, which includes the steps of adding a polyamine compound to waste water containing at least a resin to coagulate at least water-insoluble matter in the water to form coagulated particles, adding a polyacrylamide polymer to cause those particles to grow into flocculated flocs, and separating the flocculated flocs. The process of the invention can treat waste water containing a resin in an industrially beneficial way without producing a large amount of sludge is disclosed.

Abstract: A method of treating sewage or waste water for removing nitrogen and phosphorus as well as organic materials in the sewage or waste water, and an apparatus therefor are provided. The method applies intermittent aeration and dynamic flow to an equipment having at least a pair of reaction basins with intermittent aeration means, a clarifier with sludge transfer means, and a filter for passing liquid without passing solid between the reaction basins. According to the method, the efficiency of removing nutrient salts is excellent and stable even in the treatment of waste water having low content of influent organisms and low C/N ratio.

Abstract: A process for the treatment of waste waters containing chemically reducible dissolved organic and inorganic pollutants and suspended mater in particulate or colloidal form. The process comprises of contacting the water with metallic iron or ferrous ions (Fe2+), or mixtures thereof, in the presence of promoter metals, such as Cu, Pd, Pt, Au, Ag, and Ni, or oxides, sulfides and other insoluble compounds of these meals, which catalyze the redox reductions carried out by the iron or ferrous reagents. The production of ferric ions (Fe3+) as a final iron oxidation product allows for the simultaneous coagulation and precipitation of suspended colloidal and particulate solids out of the aqueous phase. In addition to the main reductive reaction scheme, the system performs a multitude of secondary reactions involving the ferrous and ferric ions produced in-situ which allows for the simultaneous removal of specific target pollutants, such as phosphate and hydrogen sulfide.

Abstract: A process for treating waste water containing cutting oil is disclosed, which includes the steps of adding a cationic organic compound to waste water containing used cutting oil to coagulate water-insoluble matter in the water and to thereby form coagulated particles, adding an anionic organic polymer to cause those particles to grow into flocculated flocs, and separating the flocculated flocs. The process of the invention can treat waste water containing used cutting oil in an industrially beneficial way without producing a large amount of sludge.

Abstract: A process for treating sulphate-containing waste water comprises introducing a feedstock comprising sulphate-containing waste water, into a pond. The sulphate-containing waste water is subjected to biological sulphate reduction in the pond, thereby to convert dissolved sulphate anions to dissolved sulphide anions. Treated waste water, containing the dissolved sulphide anions, is withdrawn from the pond.

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

Abstract: A process for treating water having anions comprising sulfur and oxygen dissolved therein involves subjecting the anions to an anaerobic biological reduction to sulfide anions dissolved in the water, followed by a biological oxidation of the sulfide anions to elemental sulfur suspended in the water. The sulfur is separated from the water. The reduction and oxidation are effected together in a series of common reaction stages in which there are oxidizing conditions which permit the biological oxidation without preventing the biological reduction.

Abstract: A compact nitrogen reduction wastewater treatment system for treating a waste liquid, the system comprising a single tank. The tank includes an inlet, an aerobic treatment compartment, an anoxic treatment compartment, a suspended micromedia compartment, an aerator, and a tank outlet. The aerobic treatment compartment includes aerobic treatment bacteria and is in fluid communication with the tank inlet. The anoxic treatment compartment is laterally disposed relative to, and in fluid communication with, the aerobic treatment compartment. The suspended micromedia compartment includes separating media. It is positioned laterally relative to, and is in fluid communication with, the anoxic treatment compartment. The suspended micromedia compartment is also laterally disposed relative to, and in fluid communication with, the aerobic treatment compartment.

Abstract: In a method and apparatus for the purification and/or treatment of communal and/or industrial wastewaters, particularly for use in marine installations, a biologically operated reaction apparatus is provided in which the wastewater to be purified and/or treated is received. In the reaction apparatus, a bio-mass of high concentration is suspended. To this reaction apparatus, the wastewater to be purified and/or treated is supplied. Subsequently, the pre-purified or, respectively, pre-treated wastewater is supplied to a membrane separation apparatus in which it is separated into a permeate and a retentate. The retentate is at least partially returned to the reaction apparatus, whereas the permeate is either discharged as useable or pure water or is returned to the reaction apparatus.

Abstract: An integrated treatment process and apparatus is provided for removing selected contaminants from both liquid and gaseous waste streams. A multistage separation and bio-oxidation substrate is provided in a column through which the contaminants are passed. The substrate components provide absorption, adsorption, ion exchange, solubility, and bio-degradation qualities to the column to effectively separate and destroy a wide range of contaminants in industrial waste streams.

Abstract: A method and equipment are disclosed for tertiary sewage treatment by naturally-occurring microorganisms after the sewage has passed from a septic tank or other primary treatment device. Tertiary treatment occurs within enclosed, controlled conditions in a recirculation tank housing a recirculating spray system and a filter bed. The recirculation process is controlled by a timer and a timer float responding to the wastewater level in the recirculation tank. A mixing zone is provided in a bottom portion of the recirculation tank.

Abstract: Disclosed is a method of decontaminating subsurface soil and/or groundwater in situ through the underground injection, immediately after mixing, of water and a powderized formulation of a dry mixture of metallic peroxides, such as calcium, magnesium, sodium, or other metallic peroxides, blended with decomposition rate modifiers, pH adjusters and iron salts, which, depending upon the concentrations of these individual compounds, generates hydrogen peroxide and subsequent powerful oxidizing agents on a desired, timed-release basis over a first relatively short period of time (e.g. several days). The reaction between the hydrogen peroxide and the iron salts produces hydroxyl and perhydroxyl radicals which rapidly oxidize organic contaminants leaving a residual which time-releases oxygen to thereafter enhance intrinsic bioremediation processes over a second longer period of time (e.g. several months).

Abstract: A method for remediating soil which is contaminated by one or more hydrophobic organic chemicals, comprising: contacting the contaminated soil with an aqueous composition comprising a surfactant prepared by reacting a sulfonate of the formula an amine wherein R1 is hydrogen or methyl, R2 is hydrogen or an alkyl group containing up to 18 carbon atoms, and each of R3, R4 and R5 is individually hydrogen or an alkyl group containing up to 7 carbon atoms and M is an alkali metal, an alkaline earth metal or —NR10R11R12 wherein R10, R11 and R12 are independently hydrogen or hydrocarbyl groups containing from 1 to 22 carbon atoms and removing said aqueous compositions and organic chemicals associated therewith from the soil.

Abstract: Waste water containing fluorine, nitrogen and organic matter is treated by introducing the waste water into a water tank filled with calcium carbonate mineral and anaerobic microorganic sludge. An upper portion of the water tank is occupied by the anaerobic microorganic sludge concurrently with natural precipitation of the calcium carbonate mineral toward a lower portion of the water tank. Calcium ions dissolving from the calcium carbonate mineral precipitated in the lower portion of the water tank are made to chemically react with the fluorine in the waste water. At the same time, the organic matter in the waste water is treated by utilizing anaerobic microorganisms in the anaerobic microorganic sludge in the upper portion of the water tank. The nitrogen in the waste water is treated to be reduced by reducibility that the anaerobic microorganisms in the waste water own.

Abstract: An acidic organics-containing waste water stream (12) derived from for example plant for the production of an aromatic carboxylic acid such as terephthalic acid is treated to allow recovery of alkali and water for recycle to the production process. The treatment comprises adjusting the pH of the waste water stream using an alakaline medium, oxidising (10) the organics content of the stream to convert the same to water, carbon dioxide and (bi)carbonate ions, and supplying the treated stream to a reverse osmosis membrane (28, 30) to produce a retentate containing (bi)carbonate ions and cations derived from the alkaline medium and a permeate which is substantially free of those components. The retentate (46) is recycled for use in adjustment of the pH of the waste water stream and, if desired, water-consuming facilities which can tolerate less pure water.

Abstract: The invention relates to a method of controlling a biological wastewater purification plant, in which the wastewater is aerated in an activation tank in the presence of an activated sludge and, to influence the properties of the activated sludge, phosphorus is added under controlled concentration, which comprises measuring the phosphorus concentration in the activated sludge for the control of the phosphorus addition and controlling the phosphorus addition in such a manner that the phosphorus concentration in the activated sludge is greater than or equal to a lower limit and is less than or equal to an upper limit. By means of the method according to the invention, the effluent values of a biological wastewater purification plant can be optimized and the limit values in the effluent of a wastewater purification plant prescribed by the authorities can be complied with better than hitherto.

Abstract: The present invention relates to a treatment method of sludge, comprising adding and mixing carbide in powder and/or particulate (carbon-containing materials, being porous and of a light weight, produced by baking in a covered pan organic matters such as used tire and rubber other than active charcoal) with sludge to adsorb and float up the sludge, and separating the sludge, and unlike conventional methods for precipitating and separating sludge by using coagulants such as Al and Ca salts and the like, no such coagulants are required, so that the separated sludge is highly safe and can be prepared as compost for recycling, and thus, highly costly incineration disposal or dumping as has been carried out conventionally is not any more needed.

Abstract: Removal of dissolved hydrogen sulfide and a reduction in BOD is achieved by the addition of nitrate ions to waste systems in an amount sufficient to stimulate growth of bacteria which utilize dissolved hydrogen sulfide in their metabolism. Specifically, about 2.4 lbs. nitrate oxygen per lb. of sulfide is required.