Abstract: Aqueous streams are purified by use of ozone in one or more purification zones wherein the ozone is drawn from one purification zone to another by use of one or more eductors in each purification zone.

Abstract: The present invention provides a method for inhibiting the growth of filamentous microorganisms. The method includes the steps of adding effective amounts of a biocide and an enzyme. The enzyme of the present invention enhances the leakiness of the protective sheath around the filamentous microorganisms to allow the penetration of the biocide into the cells of the filamentous microorganisms.

Abstract: A method of treating an aqueous system is disclosed. The method may be used to treat sewage streams as well as aqueous streams in pulp and paper mill processing. The method includes the steps of adding a polymeric composition to an aqueous stream. The composition is an anionically modified acrylamide polymer in an aqueous medium. The polymer is formed by reacting an acrylamide polymer with phosphorous acid, and has at least 5 mole percent phosphonate groups based on the acrylamide content of the polymer, and has a molecular weight of at least about 40,000. the pH of the composition is adjusted to at least about 7.7.

Abstract: A method for treating a pulp and paper manufacturing stream to remove colorants therefrom comprises: contacting the stream with a first adsorbent comprising the calcined product of a compound having the formula: A.sub.w B.sub.x (OH).sub.y C.sub.z.nH.sub.2 O, wherein A represents a divalent metal cation; B a trivalent metal cation; C a mono- to tetravalent anion; and w, x, y, z and n satisfying the following: 0<z.ltoreq.x.ltoreq.4.ltoreq.w.ltoreq.1/2y and 12.gtoreq.n.gtoreq.1/2(w-x); then contacting the stream with a second adsorbent consisting essentially of activated carbon. On a preferred basis, the first contacting adsorbent is a hydrotalcite derivative made by reacting activated magnesia with an aqueous solution of aluminate, carbonate, and hydroxyl anions before calcining at one or more temperatures between about 400.degree.-650.degree. C.

Abstract: The grit conveyance system of a classifier having a wash region above the liquid layer is provided with a vacuum means in the wash region for positive removal of liquids through a metal screen for disposal.

Abstract: White water from a paper machine is treated in an improved fiber recovery process, i.e., the "save-all" process. Prior to the mixing of sweetener stock into the white water the sweetener stock is fractionated (undiluted) into fine and coarse fiber fractions, of which only the coarse fraction is fed as sweetener stock into the white water. The inlet line for the sweetener stock is provided with a fractionation apparatus for removing the fine fraction from the sweetener stock. Treatment apparatus may also be utilized to separate the white water into fine and coarse fractions before passing the fine fraction to a mixer for mixing with the sweetener stock coarse fraction.

Abstract: The present invention provides a composition and method of administering same for inhibiting the growth of aerobic microorganisms. The composition of the present invention includes sufficient amounts of an oxidant and glutaraldehyde. The method of the present invention includes the step of adding the oxidant and glutaraldehyde to industrial process waters.

Abstract: A method is described for improving the removal of toxic resin acids and fatty acids from pulp and paper effluent and from other streams containing resins and fatty acids. The addition of an anionic material, such as albumin, gelatin, alginate or alginic acid prior to clarification with conventional or state of the art cationic coagulation clarification or retention will improve the removal of resin acids and fatty acids.

Abstract: In the bleaching of paper pulp without chlorine, such as using an OTZE or OZP bleach sequence, filtrate from subsequent stages is used as a wash liquid in preceding wash stages. The filtrate is treated with a fiber filter, and then passes through a magnesium filter, which has magnesium chips with a maximum dimension of about 3 mm or less. The magnesium removes heavy metal ions, and if any of the magnesium dissolves in the filtrate it provides a beneficial affect on the pulp. The pH of the filtrate is typically maintained in the 2-6 range to facilitate dissolution of Cu, Mn and Fe while the magnesium stays out of solution. Two filters may be provided in parallel so that if one becomes contaminated the other may be quickly put into service, and any explosive gases from the magnesium filter are vented.

Abstract: Wood-resin-containing process water or wastewater from the pulp industry is purified by adding, as flocculants, a high-molecular-weight polyethylene oxide and a water-soluble, non-ionic cellulose ether, suitably having a flocculation temperature of 35.degree.-80.degree. C. The added amount per liter of water is preferably 2-20 mg of the high-molecular-weight polyethylene oxide and preferably 5-30 mg of the non-ionic cellulose ether.

Abstract: The improved method achieves effective and economical decomposition of hydrogen peroxide and may be used in recycling hydrogen peroxide containing spent sulfuric acid that has been used in wafer cleaning and other operations in the process of semiconductor fabrication or in removing residual hydrogen peroxide that will occur either within the papermaking process or in plant effluents as a consequence of a shift from chlorine-containing bleaching agents to oxygen-containing bleaching agents.When coke was added in an amount of 10 wt % to a solution of 0.88 wt % hydrogen peroxide in 72.8 wt % sulfuric acid, followed by treatment at 60.degree.-70.degree. C. for 4 hours, the concentration of hydrogen peroxide dropped to 0.0001 wt % and below. When coke was added in an amount of 10 wt% to each of a solution (pH, 0.94) of 1.0 wt % hydrogen peroxide in 1.1 wt % sulfuric acid and a solution (pH, 2.58) of 1.04 wt % hydrogen peroxide in sulfuric acid followed by treatment at 60.degree.-70.degree. C.

Abstract: A process for removing color from a pulp and paper wastewater which comprises the following steps: (a) treating the wastewater with a reducing agent which is capable of inactivating color producing functional groups of the wastewater; and (b) treating the wastewater subsequent to step (a) with a polymer which is capable of removing color from the wastewater.

Abstract: The present invention provides a method for inhibiting the growth of filamentous microorganisms. The method includes the steps of adding effective amounts of a biocide and an enzyme. The enzyme of the present invention enhances the leakiness of the protective sheath around the filamentous microorganisms to allow the penetration of the biocide into the cells of the filamentous microorganisms.

Abstract: A hydrophobic polyelectrolyte copolymer which is useful in the removal of color in paper mill waste water. The copolymer preferably comprises an acrylamide and a hydrophobic monomer selected from the group consisting of quaternized dimethylaminoethylacrylates and quaternized dimethylaminoethylmethacrylates.

Abstract: A process for treatment of caustic sulfide liquor by wet oxidation in a ferrous-based alloy system at temperatures less than about 175.degree. C. is described. The liquor is first analyzed for alkalinity consuming species and for nonsulfidic alkalinity. If excess alkalinity consuming species is present compared to nonsulfidic alkalinity, then additional nonsulfidic alkalinity is added to the raw liquor such that excess alkalinity is present during wet oxidation treatment, thus preventing excessive corrosion to the ferrous-base alloy system.

Abstract: A process is for removal of suspended solids including resin and fatty acids from pulp mill effluents including Chemi-Thermo-Mechanical Pulp (CTMP) mill effluents. The process involves filtration of untreated or primary treated effluents through a mat of primary sludge, pulp or woodroom sludge. A sludge mat is formed on a wire screen or punched drum and the effluent to be treated is filtered through the mat. Most of the suspended solids and a part of colloidal material and dissolved solids are retained by the mat. Following the filtration stage, the sludge is dewatered and removed. A portion of the sludge is recycled to form the mat for the next filtration cycle, while the excess sludge is purged. The filtration is achieved by the application of vacuum below the filter mat or pressure over mat.

Abstract: A method for treating an ink-laden wastewater stream comprising adding an effective amount of a melamine-aldehyde polymer to the ink laden stream being treated and segregating at least some portion of the resulting ink-laden agglomerated solids from the treated water.

Abstract: The use of quaternized polyvinylamine for use in clarification of water in a deinking loop of a paper, such as newspaper, recycling operation.

Abstract: The invention relates to a process for the removal of fillers from waste paper, after floatation of the printing ink, in the presence of at least partly water-soluble polymers and/or copolymers having number average molecular weights of 1,000 to 500,000 by flotation.

Abstract: A flocculating agent which comprises: a particulate ethylene oxide polymer present in an amount of between about 20 to about 35% by weight; an inert liquid vehicle comprising a mixture of a glycol which is present in an amount between about 25 to about 30% by weight, and glycerine which is present in an amount between about 45 to about 50% by weight, wherein the specific gravity of the ethylene oxide polymer is approximately the same as the specific gravity of the inert liquid vehicle; and a suspension agent which is present in an amount between about 0.4 to about 0.6% by weight, wherein the flocculating agent has a viscosity in the range between about 1800 to about 5900 cps.

Abstract: Diallyl dimethyl ammonium chloride copolymers are effective in removing color from paper mill wastes when anionic vinyl monomers are used as the co-monomers.

Abstract: Novel copolymers of polydiallyl dimethyl ammonium chloride and 3-acrylamido-3-methylbutanoic acid are useful in the clarification of deinking paper mill waste water resulting from the processing of recycled paper stock.

Abstract: A process for the purification of acid aqueous effluent contaminated with organic material is disclosed herein. The method includes the steps of: a) bringing the aqueous effluent in contact with an iron-containing material in particulate form, wherein the particles of iron are in the metallic state; b) subjecting the material to mechanical processing in contact with the aqueous effluent while dissolving at least part of the metallic iron; c) increasing the pH of the aqueous effluent after the mechanical processing step to an essentially neutral pH; d) causing precipitation of three-valent iron under oxidizing conditions; and e) separating the precipitate from aqueous phase of step d).

Abstract: The invention provides a method for decolorizing an effluent stream from a pulp mill plant comprising the step of adding an effective amount of a decolorizing composition including a ferrous sulfate and a water-soluble cationic amine polymer.

Abstract: A method for oxidizing organic and/or heavy metal contaminants in wastewaters, sludges, or soils containing such contaminants by contacting the wastewaters, sludges, or soils with soybean peroxidase and a peroxide.

Abstract: A process and apparatus is provided for removing color from a wastewater stream. The process includes directing the wastewater stream through at least one UV reactor and simultaneously injecting a hydrogen peroxide charge into the wastewater stream exactly at the UV irradiation zone of the reactor. The apparatus of the subject invention includes a UV reactor having a smooth flow channel for wastewater and a zone for exposing the wastewater to UV irradiation. The reactor further includes tubing for directing hydrogen peroxide into the reactor exactly at the UV irradiation zone, such that the hydrogen peroxide is introduced simultaneously to the wastewater stream and the UV irradiation zone.

Abstract: Biocide treatment of the water system of a papermaking process comprising the steps of encapsulating the biocide as the core of the capsule in a water suspension, in which the shell is degradable at high water dilution, and introducing the microcapsules into the water stream to undergo dilution release.

Abstract: The present invention relates to a method of reducing the content of halogenated organic compounds in the spent bleach liquor from the bleaching of lignocellulose-containing material with compounds containing halogen, wherein the spent bleach liquor, in a stage where no essential delignification or bleaching of the pulp takes place, is maintained at a pH of from 2.5 up to about 10, and wherein the residence time and the temperature are selected such that the amount of dissolved halogenated organic substances in the spent bleach liquor is reduced by at least 30%.

Abstract: In treating effluent from an integrated paper mill having bleach plant effluent (including kraft mill effluent) and paper mill effluent (including effluent from a mechanical pulp mill) it has been found that if the two effluents are separately biologically treated and the recycled activated sludge directed to treatment of the bleach plant kraft mill effluent contains a significant portion of activated sludge derived from the treatment of the paper mill effluent that a significantly higher percentage of the absorbable organic halogens (AOX) can be removed from the bleach plant effluent.

Abstract: A process for the production of papermaking fiber or pulp from waste solids emanating from pulp and paper mills, particularly waste solids in process water streams containing fibrous solids that cannot be directly recycled by paper mill "saveall" devices, from pulp and paper mill process water streams conveyed by the sewerage system to wastewater treatment plant facilities, and from "sludge" emanating from the underflow of a primary clarifier or sedimentation basin at pulp and paper mill wastewater treatment facilities either before or after the "sludge" is thickened and dewatered.

Abstract: Disclosed is a process for preparing surface modified silica sorption agent suitable for purifying contaminated aqueous liquid, the sorption agent comprising amorphous, precipitated, silica having surface deposited thereon an organic quaternary ammonium compound.

Abstract: Mannich (alk)acrylamide microparticles are produced at high solids contents without a significant increase in bulk viscosity by inverse microemulsion polymerization and provide superior dewatering characteristics.

Abstract: A process for removal of adsorbable organic chlorine (AOX) in which the acid-soluble AOX present in kraft chlorination (C.sub.D) effluents are destablized and converted to inorganic chloride by pH shift using the alkalinity and acidity sources available at the mill; C.sub.D effluent, typically having a pH of 1-2 and E.sub.1 effluent, typically having a pH of 9-12 can be mixed in various proportions to achieve a pH between 6.5-9.0 or the C.sub.D effluent is adjusted in pH to 6-11 with an alkaline composition so taht alkaline hydrolysis as well as precipitation of organic material occurs and the treated effluent contains less AOX than present in the original untreated effluents; the AOX removal is enhanced substantially by (i) the presence of a sulphide or (ii) by carrying out the alkaline treatment at elevated temperature and pressure.

Abstract: A process for treatment of caustic sulfide liquor by wet oxidation in a nickel-based alloy system is described. The liquor is first analyzed for alkalinity consuming species and for nonsulfidic alkalinity. If excess alkalinity consuming species is present compared to nonsulfidic alkalinity, then additional nonsulfidic alkalinity is added to the raw liquor such that excess alkalinity is present during wet oxidation treatment, thus preventing excessive corrosion to the nickel-base alloy system.

Abstract: A process for removing PCDD's and PCDF's from paper mill sludge is provided. The process comprises combining the sludge with an oxidant and then oxidizing the sludge under supercritical or near supercritical conditions to destroy the PCDD's and PCDF's. Using this process, destruction efficiencies of greater than 98% have been achieved for 2,3,7,8-TCDD, which is reportedly the most toxic of the dioxins.

Abstract: A polynucleate aluminum hydroxy silicate-sulphate compound (PASS) having the following average composition:Al.sub.A (OH).sub.B (SO.sub.4).sub.C (SiO.sub.X).sub.D (H.sub.2 O).sub.EwhereinA is 1.0;B ranges from 0.75 to 2.0;C ranges from 0.30 to 1.12;D ranges from 0.005 to 0.1;X is greater than 2.0 but less than or equal to 4.0 such that 3=B+2C+2D (X-2);E is larger than 4 when the product is in aqueous form. The compound is useful for water treatment and other applications where an aluminum hydroxide gel system is required. The compound, in aqueous solution, has a long storage life.

Abstract: Waste water treatment for the removal of heavy metals is optimized by continuously removing and filtering a sample flow of treated waste water subject to pH level control to determine the presence of remaining metals in solution to be precipitated. Filtering of the sample removes metals precipitated by pH level control. Optimized pH level control can cause precipitation of most non-chelated and/or non-complexed metals, so that controlled feeding of a precipitating agent, preferably a calcium dithiocarbamate, to the treated waste water is effectively determined by only those metals remaining in solution, which are typically either chelated and/or complexed heavy metals. The filtered sample is injected with a diluted solution of the precipitating agent, and then a turbidity meter is used to determine the degree of turbidity of the injected clear sample. The resulting degree of turbidity corresponds to the level of precipitation caused by injection of the diluted precipitating agent.

Abstract: A method and apparatus are disclosed for dehalogenating and further biodegrading organic compounds, including halogenated organic compounds, present in an aqueous mixture, the mixture comprising the waste effluent produced in a continuous high flow rate by an industrial plant such as a bleach pulp or paper mill using chlorine and chlorine compounds. The aqueous mixture is passed through at least one combination of a first oxygen-enriched liquid zone and a second zone containing a mixed population of methylotrophic and heterotrophic microorganisms supported on a substrate bed. A first gas including oxygen is flowed through the first zone and second gas consisting substantially of a low-molecular-weight alkane is flowed through the second zone as the aqueous mixture passes through the first and second zones.

Abstract: A method for removing color from the caustic effluent produced during kraft pulping and bleaching is characterized by heating the caustic effluent to a temperature and under a pressure sufficient to cause an alteration in the chemical structure of the lignin chromophores in the effluent. The cooked effluent is cooled and has its pressure reduce to near atmospheric pressure. An acid material, such as chlorine extract from the bleaching process, is added to the effluent to lower the pH of the effluent to between 2.6 and 3.8 to initiate flocculation of the altered chromophores of the effluent. During flocculation, the chromophores are continuously separated from the effluent in order to produce a relatively clean and color-free liquid which may be deposited in the sewer system of the pulp mill.

Abstract: A method of removing dissolved and colloidal macro-molecular organic substances from effluents from processes used in the manufacture of pulp and paper, wherein an acid sludge containing cellulose fibres and being acidified to a pH value of 1.6-2.5, is added to an effluent containing said organic substances, and the pH value is adjusted to 4.5-6.0 before the mixture is subjected to sedimentation to achieve precipitation of the fibres with said organic substances adhered thereto. According to the invention the fibres used as precipitant are subjected to mechanical treatment prior to said acidification, so that the fibres are broken and split open, increasing their specific fibre surface and thereby their ability to catch the organic substances in the effluent.

Abstract: Co-polymers of diallyldimethyl ammonium chloride with up to 30 mole percent of a water soluble anionic monomer such as acrylic acid are superior coagulants for deinking process waters.

Abstract: A process for the production of papermaking fiber or pulp from waste solids emanating from pulp and paper mills, particularly waste solids in process water streams containing fibrous solids that cannot be directly recycled by paper mill "saveall" devices, from pulp and paper mill process water streams conveyed by the sewerage system to wastewater treatment plant facilities, and from "sludge" emanating from the underflow of a primary clarifier or sedimentation basin at pulp and paper mill wastewater treatment facilities either before or after the "sludge" is thickened and dewatered.

Abstract: Waste water treatment for the removal of heavy metals is optimized by continuously removing and filtering a sample flow of treated waste water subject to pH level control to determine the presence of remaining metals in solution to be precipitated. Filtering of the sample removes metals precipitated by pH level control. Optimized pH level control can cause precipitation of most non-chelated and/or non-complexed metals, so that controlled feeding of a precipitating agent to the treated waste water is effectively determined by only those metals remaining in solution, which are typically either chelated and/or complexed heavy metals. The filtered sample is injected with a diluted solution of the precipitating agent, and then a turbidity meter is used to determine the degree of turbidity of the injected clear sample. The resulting degree of turbidity corresponds to the level of precipitation caused by injection of the diluted precipitating agent.

Abstract: A process for the production of papermaking fiber or pulp from waste solids emanating from pulp and paper mills, particularly waste solids in process water streams containing fibrous solids that cannot be directly recycled by paper mill "saveall" devices, from pulp and paper mill process water streams conveyed by the sewerage system to wastewater treatment plant facilities, and from "sludge" emanating from the underflow of a primary clarifier or sedimentation basin at pulp and paper mill wastewater treatment facilities either before or after the "sludge" is thickened and dewatered.

Abstract: A process is disclosed for separating low molecular weight components from complex aqueous organic mixtures. The process includes preparing a separation solution of supercritical carbon dioxide with an effective amount of an entrainer to modify the solvation power of the supercritical carbon dioxide and extract preselected low molecular weight components. The separation solution is maintained at a temperature of at least about 70.degree. C. and a pressure of at least about 1,500 psi. The separation solution is then contacted with the organic mixtures while maintaining the temperature and pressure as above until the mixtures and solution reach equilibrium to extract the preselected low molecular weight components from the organic mixtures. Finally, the entrainer/extracted components portion of the equilibrium mixture is isolated from the separation solution.

Abstract: A process for decreasing the tendency to form deposits in plants for evaporating spent sulfite liquors used to produce woodpulp. In the process, the liquors are treated with polyacrylic acids having a low molecular weight. In order to prevent virtually any deposition and to increase the evaporation rate, an aqueous solution of polyacrylic acid having a low molecular weight is added to the spent sulfite liquor in an entrance stage of the multiple-effect sulfite liquor in an entrance stage of the multiple-effect evaporating system and an aqueous solution of a copolymer of sulfonated styrene and maleic anhydride or an aqueous solution of a polyacrylic acid having a low molecular weight is added to the spent sulfite liquor in at least one succeeding stage of the multiple-effect evaporating system.

Abstract: In a causticizing process for separating at least white liquor and lime sludge out of the process, filters in the form of discs or drums are arranged. The filtrations take place under positive pressure and the filters are arranged in a closed system. Such a pressure filter can also be arranged for the separation of sludge.

Abstract: The present invention solves the problem of managing resin-containing waste liquors within the cellulose pulp industry. The invention relates to a method for purifying resin-containing waste liquor in the manufacture of cellulose pulp, in which method a pH-adjusting chemical is, when necessary, added to resin-containing waste liquor removed from the cellulose pulps, so that the pH of the waste liquor will lie within the pH range 1-7, and in which a water-soluble organic polymer is added to the waste liquor in the form of a forwardly moving liquid stream. The method is characterized by dividing up the requisite amount of polymer into part quantities which are introduced into the liquid stream on at least two occasions, by subjecting the liquid stream to a pronounced shearing and/or turbulent treatment process, and by subsequently separating agglomerated resin from the waste liquor.

Abstract: A process for purifying a waste effluent from the bleaching of wood pulp by contacting the effluent with an adsorbent resin, wherein the adsorbent resin is a macroporous copolymer being post-crosslinked in a swollen state in the presence of a Friedel-Crafts catalyst and functionalized with hydrophilic groups prior to contact with the waste effluent.

Abstract: A method for removing color from the caustic effluent produced during kraft pulping and bleaching is characterized by heating the caustic effluent to a temperature and under a pressure sufficient to cause an alteration in the chemical structure of the lignin chromophores in the effluent. The cooked effluent is cooled and has its pressure reduced to near atmospheric pressure. An acid material, such as chlorine extract from the bleaching process, is added to the effluent to lower the pH of the effluent to between 2.6 and 3.8 to initiate flocculation of the altered chromophores of the effluent. During flocculation, the chromophores are continuously separated from the effluent in order to produce a relatively clean and color-free liquid which may be deposited in the sewer system of the pulp mill.