WO2007000942A1 - Procédé de traitement des eaux usées ammoniaquées - Google Patents

Procédé de traitement des eaux usées ammoniaquées Download PDF

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Publication number
WO2007000942A1
WO2007000942A1 PCT/JP2006/312593 JP2006312593W WO2007000942A1 WO 2007000942 A1 WO2007000942 A1 WO 2007000942A1 JP 2006312593 W JP2006312593 W JP 2006312593W WO 2007000942 A1 WO2007000942 A1 WO 2007000942A1
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treatment
wastewater
ammonia
nitrogen
cod
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PCT/JP2006/312593
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English (en)
Japanese (ja)
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Hideo Miyazaki
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Fujifilm Corporation
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    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12N—MICROORGANISMS OR ENZYMES; COMPOSITIONS THEREOF; PROPAGATING, PRESERVING, OR MAINTAINING MICROORGANISMS; MUTATION OR GENETIC ENGINEERING; CULTURE MEDIA
    • C12N11/00—Carrier-bound or immobilised enzymes; Carrier-bound or immobilised microbial cells; Preparation thereof
    • C12N11/14—Enzymes or microbial cells immobilised on or in an inorganic carrier
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00—Biological treatment of water, waste water, or sewage
    • C02F3/02—Aerobic processes
    • C02F3/10—Packings; Fillings; Grids
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F3/00—Biological treatment of water, waste water, or sewage
    • C02F3/02—Aerobic processes
    • C02F3/12—Activated sludge processes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W10/00—Technologies for wastewater treatment
    • Y02W10/10—Biological treatment of water, waste water, or sewage

Definitions

  • the present invention relates to a method for treating ammonia-containing wastewater, and particularly to a method for treating wastewater containing ammonia nitrogen in a high concentration or wastewater containing ammonia nitrogen in addition to ammonia nitrogen. Yes, this process is aimed at reducing the environmental load.
  • a wastewater treatment method for purifying domestic wastewater and industrial wastewater has been disclosed! These methods are mainly biological treatment, chemical treatment and physical treatment.
  • the biological treatment method is based on, for example, the activated sludge method.
  • the waste liquid is diluted and adjusted to a concentration suitable for the microbial growth environment and aerated to achieve the optimal residence time, and COD and BOD contributing components and some
  • This is a wastewater treatment method that decomposes and removes all nitrogen-contributing components.
  • Chemical treatment (oxidation method) is a chemical wastewater component decomposition and removal method such as ozone oxidation method, hydrogen peroxide ferrous salt method (Fenton method), electrolytic oxidation method and so on.
  • Physical treatment includes high-pressure heating, spray incineration, and evaporation drying. Since the characteristics of environmental pollutants in wastewater are various, the removal rate of COD may not always be high even by chemical treatment, and some of them may contain difficult-to-decompose components that are difficult to decompose even by biological treatment. is there. Physical treatment includes waste water that is costly to deal with stress corrosion of reactors, heat exchanger scale accumulation for heat recovery, residue and waste gas treatment.
  • Patent Document 1 describes a method of biological treatment using marine microorganisms after wet catalytic oxidation of photographic waste liquid
  • Patent Document 2 is a combination of hydrogen peroxide oxidation treatment (Fenton method) and microorganism treatment.
  • Patent Document 3 discloses that BOD and COD of photographic waste liquid can be reduced by a combined processing method of electrolytic oxidation processing and microbial processing.
  • Patent Document 4 discloses a combined treatment of activated carbon biological treatment and nitrification denitrification
  • Patent Literature 5 discloses a combined treatment of chemical oxidation treatment with hydrogen peroxide and nitrification denitrification treatment, but it is still not fully satisfactory, and has disadvantages such as requiring high-level operations. In particular, aerobic nitrification is extremely slow compared to the progress of the anaerobic denitrification process.
  • Patent Document 6 discloses the use of a nitrifying bacteria-immobilized carrier for the treatment of ammonia-containing wastewater
  • Patent Documents 7 and 8 disclose nitrifying bacteria-immobilized carrier treatment (nitritation). It is disclosed to use an ammoniacal nitrogen removal treatment in combination with a denitrification treatment.
  • BOD and COD can be used to reduce total nitrogen, especially ammonia nitrogen.
  • a realistic waste liquid treatment method that can reduce the total amount of nitrogen below the wastewater standard value.
  • Patent Document 1 JP-A-5-119440
  • Patent Document 2 JP-A-3-262594
  • Patent Document 3 Japanese Patent Laid-Open No. 4235786
  • Patent Document 4 JP-A-9-85291
  • Patent Document 5 Japanese Patent Laid-Open No. 9-94597
  • Patent Document 6 Japanese Patent Laid-Open No. 9-47788
  • Patent Document 7 JP-A-9-75984
  • Patent Document 8 Japanese Patent Laid-Open No. 2001-170684
  • the present invention has also been provided with the above-described background force, and its object is to provide a wastewater treatment method capable of reducing at least the amount of ammonia nitrogen in wastewater to a level that satisfies the drainage standards based on the Sewerage Law.
  • the larger objective is to present a wastewater treatment method that can reduce the total nitrogen content and the amount of ammonia nitrogen to a level that meets the wastewater standards under the Sewerage Law. It is to provide a wastewater treatment method that can reduce the total nitrogen amount to a level that meets the wastewater standards based on the Sewerage Law.
  • Another objective of the present invention is that the total amount of nitrogen and the amount of Z or ammonia nitrogen are high.
  • the present inventor has made extensive studies focusing on the relationship between the habitat environment and nitrification activity of ammonia acid bacterium (nitrifying bacteria). Bacteria have been found to exhibit a significant improvement in nitrification activity when placed in a coexistent state in an inorganic dispersion and a entrapped immobilization body.
  • the present invention has been reached. That is, the present invention is as follows.
  • a wastewater treatment method comprising: treating with a entrapping immobilization body containing ammonia acid bacteria and an inorganic dispersion.
  • the inorganic dispersion is an inorganic dispersion mainly composed of at least one selected from carbon, aluminum oxide and silicon oxide. Processing method.
  • the entrapping immobilization body of ammonia acid bacterium is a entrapping immobilization substance comprising the bacterium encapsulated in a gel mainly composed of polybulal alcohol (PVA), according to (1) to (3) above.
  • PVA polybulal alcohol
  • the wastewater treatment method of the present invention is characterized in that ammonia nitrogen is decomposed and removed under conditions using a entrapping immobilization body in which ammonia acid bacteria and an inorganic dispersion coexist.
  • a method for improving the biodegradation efficiency by entrapping and fixing biodegradable bacteria There is known a method for improving the biodegradation efficiency by entrapping and fixing biodegradable bacteria.
  • the degradation efficiency is significantly improved by the entrapped fixed body dispersion system in which the inorganic dispersion coexists with ammonia-oxidizing bacteria.
  • T—N ammoniacal nitrogen concentration
  • the present invention can be applied to any wastewater containing high ammonia nitrogen, but it is effective to use it for wastewater other than photographic wastewater, that is, wastewater to which halophilic bacteria such as marine bacteria cannot be applied. is there.
  • the ammoniacal nitrogen reduction treatment method of the present invention is provided with a physical or biological treatment as a pre-stage of the above-mentioned ammoniacal nitrogen decomposition / removal step, and a combination of this pre-treatment and treatment with ammonia oxidizing bacteria. Even if the wastewater treated by the effect has high chemical oxygen demand (COD) and the total nitrogen component including ammonia nitrogen is also high, the effect is great. For example, if the chemical oxygen demand (COD) is 0.3 gZL or higher, ammonia nitrogen Both COD and ammoniacal nitrogen can be reduced to a sufficiently low level for wastewater with an elementary amount of 0.5 gZL or more.
  • the COD reduction treatment combined with such ammoniacal nitrogen content reduction treatment includes electrolytic oxidation treatment using a diamond electrode, especially physicochemical treatment or biological treatment (biological treatment). It can be said that it is an excellent wastewater treatment method in that it can remarkably reduce the difference between SCOD and ammonia nitrogen.
  • Electrolytic oxidation treatment using a conductive diamond electrode as an anode is effective in reducing oxygen consumption! Although it is superior to other anode oxidation treatments, it is particularly characteristic that the components contributing to the total amount of nitrogen remaining after electrolytic oxidation treatment are easily decomposed by microbial treatment, and the nitrogen removal efficiency is improved. . As a result, it is possible to reduce both the BOD and COD of wastewater, the total nitrogen content (T—N), and the amount of ammonia nitrogen to levels that meet the drainage standards based on the Sewerage Law.
  • Known denitration and denitrification microorganisms are used for the treatment of reducing the total amount of nitrogen by microorganisms.
  • the biological activity is improved by fixing ammonia acid bacteria (nitrifying bacteria) on a carrier.
  • Another feature of the wastewater treatment method of the present invention is that it can treat wastewater with a relatively high ammonia nitrogen content, so that when the total nitrogen content reduction treatment by microorganisms is performed after the electrolytic treatment, or without diluting with water, This means that processing can be performed at a relatively low dilution factor, so that a large processing space is not required and the equipment can be downsized.
  • the wastewater subject to the present invention includes BOD, COD, ammoniacal nitrogen and total nitrogen, which may be misaligned wastewater! /, But is not applicable to photographic processing wastewater! Photographic wastewater is excluded from the scope of the present invention in that it is generally high in salt concentration.
  • the invention's effect is not applicable to photographic processing wastewater! Photographic wastewater is excluded from the scope of the present invention in that it is generally high in salt concentration.
  • the waste liquid treatment method of the present invention characterized by combining a physicochemical treatment, a biological treatment, and a nitrogen reduction treatment in the presence of an inorganic dispersion and a entrapped immobilization body of ammonia-oxidizing bacteria is 0.5 gZL. It is possible to decompose and remove wastewater containing high concentrations of ammonia nitrogen to a low level that meets the wastewater standards. It also has the same effect on wastewater with a large amount of total nitrogen (TN). In addition to ammoniacal nitrogen Even wastewater containing oxygen-consuming components can reduce both BOD, COD, and TN to a level that meets the wastewater standards based on the Sewerage Law.
  • microorganism related to biodegradation may be called “bacteria”, but may be understood substantially synonymously.
  • the present invention is suitable for the treatment of wastewater with a high ammoniacal nitrogen content.
  • the “ammonia nitrogen content” here refers to the “ammonia nitrogen content” according to the drainage standards for the Water Pollution Control Law.
  • High-ammonia nitrogen wastewater includes domestic wastewater derived from in-house treatment tank residue, living environment wastewater such as anaerobic urine treatment residue and its extraction water, boiler irrigation, chemical factory wastewater, food processing factory wastewater, etc.
  • living environment wastewater such as anaerobic urine treatment residue and its extraction water, boiler irrigation, chemical factory wastewater, food processing factory wastewater, etc.
  • wastewater treatment method of the present invention There are a wide variety of wastewater from agriculture, fisheries, and livestock industry, and these are the targets of the wastewater treatment method of the present invention.
  • the wastewater treatment method of the present invention is suitable for wastewater containing a high concentration of ammonia nitrogen, and the amount of ammonia nitrogen is 0.5 gZL or more and less than 8 gZL, preferably 0.5 gZL or more and less than 7 gZL, more preferably 0. Applies to wastewater of 5gZL or more and less than 6gZL.
  • the wastewater treatment method of the present invention is not limited to high ammonia nitrogen wastewater.
  • the present invention can be preferably applied to wastewater containing both ammoniacal nitrogen and total nitrogen and COD contributing components, and can effectively reduce any of ammoniacal nitrogen, total nitrogen, and COD contributing components.
  • biological treatment or physicochemical treatment especially electrochemical treatment is performed in the first stage !, and then nitrification denitrification treatment for reducing ammonia nitrogen content in the second stage.
  • preconditioning such as water dilution so that the amount of ammoniacal nitrogen falls within the above range.
  • the COD, total nitrogen amount, ammonia nitrogen, etc. of waste water in this specification are characteristic items used as normal water quality environmental indicators, and are COD defined in JIS K0102 (Industrial Wastewater Test Method), Based on the test method for total nitrogen and ammonia nitrogen.
  • the nitrification denitrification process will be described.
  • the waste water contains inorganic nitrogen compounds such as ammonia, nitrous acid, and nitric acid
  • the nitrogen removal can be performed biologically.
  • Nitrous acid and nitric acid are removed as nitrogen by denitrifying bacteria under anaerobic conditions.
  • ammonia nitrification is required first, and nitrification is divided into nitritation and nitrification.
  • Nitrite is performed by nitrite (Nitrosomonas)
  • nitrification is performed by nitrite (Nitrobactor).
  • Nitrite bacteria and nitrate bacteria are collectively called nitrifying bacteria.
  • nitrifying bacteria have a low growth rate, it is necessary to prevent nitrifying bacteria from flowing out in order to increase the cell concentration in the treatment tank. For this purpose, for example, by holding the SRT (sludge retention time) long, fixing the nitrifying bacteria to the adherent carrier, fixing the nitrifying bacteria inclusive, There is a method of increasing the concentration of nitrifying bacteria in the treatment tank, but in the present invention, the waste water treatment is carried out in a dispersion system in which the nitrifying bacteria coexist with the inorganic dispersion and are immobilized. Is a feature.
  • This combined nitrifying / inorganic dispersion treatment can provide a significant nitrifying / denitrifying effect compared to the conventional nitrifying / denitrifying treatment.
  • an organic compound as a hydrogen donor is required.
  • organic substances in raw water can be used as the organic carbon source, methanol, acetic acid, etc. are added if insufficient.
  • POD is practically converted to nitrate nitrogen (NO -N) lKg.
  • a denitrifying bacterium such as Thiobacillus denitrificans may be used as a denitrifying bacterium.
  • Nitrous denitrifying bacteria are nitrates, or nitrite is reduced to nitrogen gas by using electron acceptor, while elemental thiosulfuric acid is oxidized to sulfate by electron donor. Accordingly, since io and thiosulfate can be used for denitrification, it is possible to perform an inexpensive denitrification treatment without using organic chemicals such as methanol.
  • Inorganic dispersions that coexist with a dispersion in which nitrifying bacteria are entrapped and fixed include inorganic particles mainly composed of acid aluminum such as alumina, porous silica, colloidal silica, silica gel, incineration fly ash Simple particles such as acid silicate and porous ceramics, activated carbon, simple carbon particles such as bone charcoal and charcoal, clay minerals such as kaolinite and montmorillonite, activated clay, synthetic or natural zeolite, anthracite, gravel, sand, One or more of pumice and diatomaceous earth can be used.
  • the inorganic dispersion includes inorganic particles mainly composed of acid aluminum such as alumina, porous oxides such as porous silica, colloidal silica, silica gel, incineration fly ash, activated carbon, bone charcoal, charcoal, etc. These are carbon simple particles, among which alumina, silica gel, incineration fly ash, and activated carbon are preferable.
  • the carrier particles have an outer diameter of 0.1 to 70 mm, preferably 0.5 to 40 mm, more preferably
  • the shape of the inorganic dispersion is arbitrary, but a porous one and a large specific surface are preferable.
  • the feature of the comprehensive fixation method is that the bacterial cells can be maintained at a high concentration, so that the treatment efficiency can be improved and the slow-growing bacteria can be fixed. It can also withstand high load conditions with wide resistance to changes in conditions such as pH and temperature.
  • a comprehensive immobilization method acrylamide Method, agar acrylamide method, PVA boric acid method, PVA freezing method, photo-curable resin method, acrylic synthetic polymer resin method, sodium polyacrylate method, sodium alginate method, K-force laginan method, etc. Any material can be used as long as it has a high physical strength and can withstand long-term use while maintaining the activity of microorganisms in the system.
  • a method for preparing a microorganism-immobilized gel in the case of the acrylamide method will be described as a representative example of the comprehensive immobilization method.
  • the fixed gel gel suspends an acrylamide monomer solution containing a cross-linking agent (for example, N, N'-methylenebisacrylamide) and bacteria (concentrated cells of MLSS 20, OOOppm) and suspends the polymerization accelerator (for example, N, N, ⁇ ', N'-tetramethylethylenediamine) and a polymerization initiator (for example, potassium persulfate) are added and put into a molded shape such as a 3 mm diameter chlorinated tube, 20 ° Polymerized with C, and after polymerization is completed, it is obtained by extruding the molding force and cutting it to a certain length.
  • a cross-linking agent for example, N, N'-methylenebisacrylamide
  • bacteria concentrated cells of MLSS 20, OOOppm
  • the polymerization accelerator for example
  • the bacteria that are inclusively immobilized grow on the inside where it is difficult to leak and self-decompose. Only the contaminating components in the waste liquid enter the gel through the pores and are treated by the bacteria inside.
  • PVA method, acrylamide method and the like are preferable for entrapping and fixing nitrifying bacteria. More specific methods for the immobilization of these are described in the documents mentioned above. These treatments may be continuous or batchwise.
  • Nutrient salts such as nitrogen and phosphoric acid do not usually need to be added, but they need to be added particularly when phosphorus is insufficient.
  • the temperature is preferably 20 to 35 ° C, more preferably 30 to 35 ° C.
  • the pH is 6.5 to 8.5, more preferably 7.0 to 8.0.
  • the treatment time varies depending on the treatment method, the ammonia concentration in the liquid to be treated, and the target treatment level, and preferably 1 to 5 days, more preferably 1 to 3 days.
  • the treatment load is preferably a nitrogen load of 0.2 to 0.7 kg-N / (m 3 ⁇ day).
  • the denitrification step after the nitrification step may be performed immediately after the nitrification step or after any treatment. Also, the denitrification process may be provided before the nitrification process, and the nitrification process treatment solution may be returned to the denitrification process!
  • the denitrification process is carried out in an anaerobic atmosphere (method of treatment without aeration), and denitrification proceeds easily.
  • organic compounds such as methanol, propanol and acetic acid, biologically treated sludge, thiosulfate and the like can be used.
  • the denitrification process is provided immediately after the electrolysis process, and the processing liquid of the subsequent nitrification process is returned.
  • the amount returned from the nitrification step is preferably 1 to 4 times, more preferably 2 to 3 times, the amount fed to the denitrification step from the first step. If the return amount is too large, the cost of power for the return pump will increase, and the nitrification process power will bring about a decrease in denitrification efficiency due to the introduction of dissolved oxygen into the denitrification tank.
  • Biological treatment methods used in the denitrification step include biological suspensions such as activated sludge method, three-phase fluidized bed method, sponge carrier method, biological filtration method, submerged filter bed method, fluid bed method, etc. Membrane method, entrapment method, etc. can be used. Among these methods, submerged filter bed method and granular carrier are used among the biofilm methods preferred by microbial suspension method and biofilm method. The biological filter method and the fluidized bed method are preferred.
  • activated carbon for the denitrification process it is possible to combine the denitrification process with the decomposition of persistent substances after the aerobic biological treatment of the waste liquid to be treated.
  • the decomposition of the hardly decomposable substance is preferably a treatment under cometabolism conditions and anaerobic conditions.
  • an aerobic treatment In order to remove COD components remaining in the denitrification step, it is preferable to perform an aerobic treatment after the denitrification step.
  • Biotreatments used for aerobic treatment include microbial suspension methods such as activated sludge method, three-phase fluidized bed method, sponge carrier method, biofiltration methods such as biofiltration method, submerged filter bed method, fluid bed method, etc. Among these methods, the biofilm method is preferable.
  • the iron component and phosphorus are removed as necessary. Most of the iron component is removed as an insoluble component in the electrolytic oxidation process. If further iron removal is required, the treatment solution can be made alkaline to remove the iron ions by insolubilization, or the iron ions can be removed with phosphate and Z or other inorganic salts at pH 4 to 7.5. Examples of the method include removing the precipitate as a complex salt, and these are described in JP-A-4235787.
  • physicochemical treatment methods such as lime coagulation precipitation, Lumi-um coagulation precipitation method, iron coagulation precipitation method, crystallization method using phosphate ore, bone ash, magnesia tarinka, apatite, etc. as seed crystal, adsorption method using activated alumina, chelating resin, etc., iron contact
  • the method used, the ion exchange method, etc. can be used. These methods are described in detail in “Denitrification Dephosphorization Technology and Nutrition” (IPC).
  • the biological treatment or physicochemical treatment whose main purpose is to reduce the COD value is an organic material whose main purpose is nitrification denitrification. Combined with nitrification / denitrification treatment by entrapping immobilization bacteria coexisting with dispersion.
  • the physicochemical oxidation treatment is a treatment in which the oxidizing agent is not left as a reaction product other than water, oxygen, hydrogen, carbon dioxide or carbonate ions in the waste liquid after treatment.
  • oxidation treatment with an oxidant selected from oxygen, ozone, hydrogen peroxide, and percarbonate active light irradiation treatment such as ultraviolet rays in the presence of these oxidants, electrolytic oxidation treatment, and active light irradiation.
  • electrolytic oxidation treatment with an oxidant selected from oxygen, ozone, hydrogen peroxide, and percarbonate active light irradiation treatment such as ultraviolet rays in the presence of these oxidants
  • electrolytic oxidation treatment and active light irradiation.
  • Preferred physicochemical oxidation treatments are electrolytic oxidation treatment, ozone oxidation treatment, hydrogen peroxide oxidation treatment, and a combination treatment of these with ultraviolet irradiation, but the treatment particularly preferred in the present invention is electrolytic oxidation treatment. .
  • wastewater is adjusted to pH using an alkaline agent such as sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate or the like before or during electrolysis. May be.
  • an alkaline agent such as sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate or the like before or during electrolysis. May be.
  • a waste liquid containing an iron compound that easily becomes an insoluble precipitate (floating matter) it is preferably removed by filtration or sedimentation.
  • alkaline pH is preferable.
  • the added alkaline agent may be in any form of solid, aqueous solution, suspension, etc. It may be added prior to the treatment, or electrolysis may be recommended in conjunction with an automatic adjustment device.
  • the pH may be adjusted to be maintained above 7 during the electrolysis operation, preferably above pH 8.
  • the pH is preferably 12.5 or less in order to suppress precipitation formation due to hydrolysis of the iron complex salt compound.
  • the electrolysis may be either a batch method or a continuous method.
  • this process preferably reduces the COD in the effluent by 10-6O%, often 20-50%, depending on the degree of electrolytic oxidation.
  • the major advantage of electrolytic oxidation treatment is that it is easy to remove the components that contribute to the total amount of nitrogen remaining in the electrolytically oxidized liquid as described above, as well as the effect of reducing COD. As a result, the reduction rate of the total nitrogen amount may be improved.
  • the electrolytic cell is preferably selected from platinum, ferrite, stainless steel, iron on which an oxide film is rapidly formed, and the like, which are corrosion-resistant materials that resist corrosion.
  • the cathode is an electron donating electrode and does not directly participate in the electrolysis reaction, but platinum, stainless steel, etc., which are materials inert to the reaction solution, are preferable.
  • a ferrite electrode is preferable for the anode, and a stainless electrode or the like is preferable for the cathode.
  • a rotating negative electrode is used to prevent precipitation of the suspended matter on the electrode, to cause a uniform acid / acid reaction, and to increase current efficiency. Is preferred.
  • the power that is a well-known anode such as lead dioxide, carbon (graphite, glassy, etc.), iron, stainless steel, nickel, etc. is used in the present invention.
  • a conductive diamond electrode This makes it possible to efficiently perform the electrolysis of the hardly decomposable substances in the waste liquid. In particular, even if the substances that contribute to the total amount of nitrogen remain in the treated liquid, it is easy to undergo biological treatment! .
  • the term “conductive diamond electrode” means a diamond electrode having an electrical resistivity of less than 1 M ⁇ cm, but “conductive” may be omitted as long as there is no fear of misunderstanding. .
  • Diamond which is an electrode material for anodes, is made of powder diamond made of titanium, -ob, tantalum, silicon, carbon, nickel, tungsten carbide, etc. as a substrate, punched plate, wire mesh, powder sintered body, metal fiber
  • the electrode may be formed by coating the surface of a sintered body or the like by the method described later, or plate-like diamond may be used as it is, but it is preferable to use the former for the cost surface. .
  • the diamond coating layer in the former is referred to as a diamond layer.
  • the material of the intermediate layer a metal carbide or oxide constituting the substrate can be used.
  • the substrate surface may be polished or conversely roughened to contribute to adhesion and increased reaction area.
  • the electrode material may contain a small amount of other electrode materials!
  • Hot filament CVD microwave plasma CVD, plasma arc jet, PVD, and the like have been developed as methods for forming the diamond layer on the substrate surface.
  • a typical hot filament CVD method will be described.
  • the electrode substrate is placed in another temperature (750 to 950 ° C.) region where diamond is deposited.
  • the preferable organic compound gas concentration with respect to hydrogen is 0.1 to 10% by volume
  • the feed rate is 0.01 to 10 liters Z minutes depending on the dimensions of the reaction vessel, and the pressure is 15 to 760 mmHg.
  • the diamond fine particles usually have a particle size of about 0.01 to 5 ⁇ m.
  • diamond powder is deposited on the substrate according to the above conditions to have a thickness of 0.1 to 50 ⁇ m, preferably 1 to 10 ⁇ m. A thick diamond layer. This thickness is suitable for preventing the electrolyte from entering the substrate.
  • a trace amount of elements having different valences for example, phosphorus or boron is l to 100,000 ppm, preferably about 100 to 10,000 ppm. Contain.
  • a compound having low toxicity such as acid boron or pentanoic acid aniline is preferable.
  • PECVD plasma enhanced CVD
  • the PECVD diamond layer is a boron-doped polycrystalline diamond that has also produced a mixture of methane and hydrogen gas activated by microwave plasma.
  • the deposition of diamond layers by this method is well understood by those skilled in the art (see, for example, Klages, Appl. Phys. A56 ⁇ (1993), pages 513-526).
  • Diamond layers produced by the hot filament CVD (HFCVD) method are based on Advanced Technology Materials. In, 7 Co mmerce Drive, Danbury. CT 06810, commercially available from the United States.
  • HFCVD hot filament CVD
  • the chemical vapor deposition method described in paragraph 0007 of JP-A-8-225395 is also preferred.
  • a cathode for electrolytic acid bath if it has sufficient corrosion resistance and electric conductivity so as not to cause corrosion during the rest period of electrolysis!
  • a plate or bar is particularly suitable.
  • other electrodes such as carbon electrodes and various metal electrodes can also be used.
  • An appropriate shape such as a negative electrode / anode pair shape, a sandwich structure in which the negative electrode is sandwiched between the anodes, or a multi-layer structure in which the cathode and anode are alternately arranged is selected.
  • the shape of the cathode may be any of a linear shape, a rod shape, a plate shape, and the like.
  • a conductive diamond electrode can also be used for the cathode.
  • conductive diamond electrodes are used for both electrodes, it is preferable to perform electrolysis while reversing the polarity in order to maintain the electrodes in a normal state.
  • calcium hydroxide or magnesium ion hydroxide or the like adheres to the cathode surface of the electrolytic cell, so periodic scale removal is necessary.
  • devices for reversing the polarity of electrodes for a very short time JP-A-3-109988, JP-A-5-4087, JP-A-6-63558, etc.
  • the deposits on the cathode surface of the electrolytic cell are converted into calcium ions and magnesium ions by reversing the polarity of the electrodes, that is, by positively polarizing the deposit surfaces of the hydroxides and the like. It is possible to proceed with the electrolytic reaction while re-dissolving in the water to be treated and removing it from the electrode. No special provision is required for the inversion interval and time as long as both poles have the same shape.
  • the current density during electrolytic oxidation is generally about lOmAZcm 2 and the voltage drop at the electrode is in the range of 10 to: LOOV. Therefore, the power consumption, which is the product of the square of the current value and the resistance value, is extremely high. As a result, it becomes large and a considerable amount of energy is lost due to resistance heating.
  • the preferred electrode for the present invention is that the diamond layer has a resistivity of less than 1 ⁇ cm.
  • the diamond layer thickness is sufficiently thin (less than 5 m), and the substrate has a sufficiently high conductivity.
  • the electrode is an electrode having a diamond layer with a resistivity of less than 100 ⁇ cm and a thickness of less than IV with a current density of lOOmAZcm 2 and a voltage drop of less than IV. With such an electrode, the power loss caused by the resistance heating force can be kept low at an appropriate current density.
  • a preferred electrode is an electrode having a resistivity of less than 0.1 ⁇ cm, a current density of lAZcm 2 and a thickness such that the voltage drop at the electrode is less than 0.1 IV.
  • the structure of the electrolytic cell can be used in various known configurations. That is, it may be a single-chamber cell or a divided cell in which the anode and the cathode are partitioned by a film.
  • the simplest embodiment is a single chamber cell. In a single chamber cell, there is no barrier separating the anode and cathode, so the solute is not restricted from moving between the anode and cathode.
  • a conductive membrane such as an ion exchange membrane, a microfiltration membrane, a semipermeable membrane, and a porous membrane is inserted between the anode and the cathode, and this membrane is a certain type of ion. Only seeds can be passed through the anolyte catholyte or vice versa. The function of the membrane is to maintain electrical neutrality without mixing the anolyte and the catholyte. In addition, if an appropriate film is used, the nature of ions moving through the film can be controlled.
  • the electrolytic acid solution according to the present invention is a method that is most convenient as appropriate depending on the scale of the waste liquid treatment and the degree of treatment, which may be a batch method, a recirculation method, a continuous method, or a deviation method. Can be selected.
  • An electrochemical cell containing a diamond layer electrode keeps the gap between the electrodes as small as possible without causing a direct connection between the anode and the cathode, or a path that causes a short circuit. Larger than a few centimeters, the distance between the electrodes is acceptable, the gap between the electrodes is 0.1 mm to 50 mm, and the most preferable state is that the interelectrode gap is in the range of 0.5 mm to 20 mm.
  • the current density is lmAZcm 2 ⁇ 10AZcm 2, a flow rate Z cell volume ratio 0. 001 ⁇ 1000s _1, electrode surface area greater than the geometric surface of the electrode is equal to the force or measured by microscopy In particular, the surface area is preferably 1 to 5 times the surface of the geometric electrode.
  • the current density is in the range of 20 mA / cm 2 to 2 A / cm 2 and the flow velocity / cell volume ratio is 0.01 to 50 s _1 , and the best mode of the present invention is that the current density is 50 mAZcm 2 to 800 mAZcm 2.
  • the flow rate Z cell volume ratio is in the range of L ⁇ 20s _1, electrode surface area, more preferably at least in the case of twice the geometric electrode surface area as measured by a microscope.
  • the preferred amount of electricity depends on the COD of the waste liquid to be treated. Usually 0.5MQ or more, preferably 1 to 10MQ, more preferably 2 to 8MQ per liter of photographic waste liquid (MQ is megacoulomb) .
  • the COD value is high in comparison with the ammoniacal nitrogen of the wastewater, it can be combined with aerobic biological treatment as a pretreatment for nitrification denitrification treatment.
  • This type of wastewater is preferably diluted with water to a COD value suitable for biological treatment.
  • Dilution with water is usually about 10-50 times, preferably about 10-: L00 times, but excessive water dilution is disadvantageous for the nitrification denitrification process, so combine the nitrification denitrification process.
  • a method in combination with an aerobic biological treatment is possible, but an aspect in combination with physical physical treatment is more preferable.
  • a biological treatment method As a biological treatment method, a generally known aerobic biological treatment can be applied.
  • a method such as a lagoon method, a sprinkling filter bed method, a rotating disk method, etc., which contains aerobic microorganisms in a non-treated liquid and is in contact with aeration or air or oxygen. It can be used for the biological treatment of the present invention.
  • a compact bioreactor with aeration tank power equipped with a waste liquid inflow system, a sludge separation / return system, and a treated waste liquid discharge system is preferred.
  • a preferred aerobic biological treatment method is a treatment method carried out in a form in which a microorganism is supported and immobilized on a carrier.
  • the comprehensive process is particularly preferable.
  • the method for producing the microorganism-fixing carrier is not limited to the type or form of the microorganism-supporting / fixing method, as long as it is a method in which biodegradable bacteria are not released from the carrier.
  • an attached biofilm method using a carrier that attaches microorganisms to form a biofilm a supported culture method that cultures microorganisms by mixing a carrier and a medium, a carrier binding method that binds microorganisms to a water-insoluble carrier, A method of encapsulating microorganisms in the pores of the carrier under reduced pressure, a method of immobilizing a microorganism by forming a cross-link with a reagent having two or more functional groups, and confining microorganisms inside a high-molecular gel or film Forces that are known to include the carrier-fixing method, which is classified as a comprehensive immobilization method, a covalent binding method, a physical adsorption method, an i
  • the feature of the attached microbial membrane method is that the concentration of microorganisms can be increased and the treatment efficiency can be improved. In addition, bacteria with a slow growth rate that would normally be washed out of the system can remain in the system. Another characteristic is that microorganisms can be kept in a stable state.
  • Fuji Photo Film Co., Ltd. End-of-life treatment facility at Ashigara Factory The collected activated sludge is used as a seed fungus and is supported on the following various carriers, and then cultured in a culture medium based on the following HEPES buffer. While gradually increasing the ammonia concentration in the liquid, nitrifying bacteria suitable for high concentrations of ammonia were acclimatized and grown.
  • BCP carrier BC PP PE, PS, activated carbon Te ', Nkaenshi', Your Link ',
  • PVAZ boric acid carrier PB PVA, boric acid (Prepared this time)
  • PVAZ boric acid carrier B PBB PVA boric acid, activated alumina (Prepared this time)
  • LOOmL of KU or BC was added while supplying air to a ball filter for aeration installed in the factory.
  • 100 ml of activated sludge collected from the final treatment facility of the factory was allowed to stand, and the flocs that settled were placed in the flask as a reaction vessel, and aeration was continued for 3 days to adsorb microorganisms.
  • the carrier was removed and subjected to conditioned culture.
  • the above activated sludge was mixed with an 18% PVA (Kuraray PVA-HC) aqueous solution at a weight ratio of 1: 1, and dropped into a saturated boric acid aqueous solution in a spherical shape through a glass tube with a narrowed tip.
  • the gel beads formed instantaneously were gently stirred for 24 hours to completely gel.
  • the beads were then deborated in pure water for 3 days and subjected to conditioned culture.
  • PVAZ boric acid carriers A to C consist of activated carbon, activated alumina (manufactured by Wako Pure Chemical Industries), and incineration fly ash (collected from Ashigara Factory's private power generation furnace). In each case, 5% by volume was added to an 18% PVA aqueous solution to prepare gely gel as described above.
  • Table 2 shows the time required to reduce 25000 mgZL of ammonium sulfate to lOOOmgZL in a simultaneous treatment experiment using the conditioned medium.
  • Quantitative analysis of nitric acid, nitrous acid and ammonia was performed by ion chromatography.
  • the present invention [0066]
  • the entrapped immobilization dispersion sample (Nos. 4 to 6) interposing the inorganic dispersion of the present invention example quickly adapts to the amount of high ammonia nitrogen and decomposes ammonia nitrogen to lOOOmgZL. The time required for this is also significantly reduced.
  • a model liquid of the waste water was prepared in order to try to apply it to the treatment of waste water from a coke oven furnace, known for its high ammonia content. That is, a solution of phenol 1.5 g / cresol 1.5 / ammonium thiosulfate lgZL and ammonium sulfate 13 gZL was prepared. The COD of this solution was 11000 mgZL and ammonia was 3400 mgZL. This was subjected to the electrolytic oxidation treatment described below, and then the treatment with the conditioned nitrifying bacteria used in Example 1 was performed.
  • the diamond electrode used was a boron-doped diamond layer electrode. Boron-doped polycrystalline material in which boron was included in a diamond layer deposited on a (100) single crystal silicon wafer (0.76 mm thickness). A diamond layer (approx. 2.5 ⁇ m thick), which is commercially available from Advanced Technology Materials, Inc., 7 Commerce Drive, Daubury, CT 06810, USA, was used. The resistivity of this diamond layer was 80 m ⁇ cm, and the doped boron concentration was 5000 mg / kg.
  • the resistivity of silicon wafer was 15m ⁇ cm.
  • the copper wire is fixed to the silicon substrate using commercially available silver epoxy resin (Epo-Tek H20E, Epoxy Technology In), and the leakage of the solution to the back side of the electrode is minimized using RTV silicone.
  • the back surfaces of the diamond electrodes are bonded together to seal the critical surface.
  • As the platinum electrode a commercially available platinum-coated electrode plate was used as it was.
  • the applied voltage between each pair of electrodes is 3.5V for the diacid lead anode and 5V for the platinum anode, Diamond anode force V.
  • reaction solution after electrolysis was neutralized to pH 6.5 with granular potassium hydroxide and filtered to remove the precipitated solid.
  • Table 3 shows the COD and ammonia concentrations of each solution.
  • Table 3 shows that 50% or more of the COD value of the stock solution of 6000 mgZL can be removed by electrolytic oxidation even if the electrolytic oxidation is not performed.
  • the diamond electrode is used as the anode (sample C) Showed a remarkable COD reduction effect with a residual COD of 95 mgZL.
  • Table 4 shows examples of the present invention that were tested by comprehensive fixation of nitrogen-degrading bacteria (No. 4-6, 10-12, 15-18 showed excellent nitrification and denitrification effects.

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  • Immobilizing And Processing Of Enzymes And Microorganisms (AREA)
  • Biological Treatment Of Waste Water (AREA)
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Abstract

L'invention vise à fournir un procédé de traitement des eaux usées selon lequel au moins la teneur en azote ammoniacal et la demande chimique en oxygène (DCO) des eaux usées peuvent être abaissées à des niveaux satisfaisant les normes de l’effluent selon la loi des eaux d’égouts (Sewage Water Law). La présente invention concerne un procédé de traitement des eaux usées caractérisé par le fait de soumettre une eau usée (à l’exception des déchets liquides provenant d’un développement photographique) qui a une DCO supérieure ou égale à 0,3 g/L et une teneur en azote ammoniacal supérieure ou égale à 0,5 g/L à un traitement physico-chimique ou biologique et ensuite de traiter l'eau usée résultante au moyen d’un traitement comprenant des bactéries oxydant l'ammoniaque et un support de dispersion inorganique sur lequel les bactéries sont inclusivement immobilisées.
PCT/JP2006/312593 2005-06-27 2006-06-23 Procédé de traitement des eaux usées ammoniaquées WO2007000942A1 (fr)

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CN104192986A (zh) * 2014-08-01 2014-12-10 浙江大学 渗流自充氧菌毯短程硝化反应器及其废水处理方法
CN111439824A (zh) * 2020-03-06 2020-07-24 浙江正洁环境科技有限公司 具有促菌性能的水处理生物膜载体及其制备方法和应用
JP7421708B2 (ja) 2019-11-01 2024-01-25 国立大学法人長岡技術科学大学 微生物担体及び廃液処理方法

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JP4956016B2 (ja) * 2006-02-28 2012-06-20 水ｉｎｇ株式会社 難生物分解性物質含有有機性排水の処理装置および処理方法
WO2018029200A1 (fr) * 2016-08-10 2018-02-15 Covestro Deutschland Ag Procédé de purification électrochimique de solutions de traitement contenant des chlorures

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JP2005262035A (ja) * 2004-03-17 2005-09-29 Fuji Photo Film Co Ltd 写真廃液の処理方法
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JPH10230292A (ja) * 1996-11-01 1998-09-02 Hitachi Plant Eng & Constr Co Ltd 窒素除去方法及び装置並びに包括固定化担体
JPH11123076A (ja) * 1997-08-22 1999-05-11 Takeda Chem Ind Ltd 生物処理用担体
JP2002233885A (ja) * 2001-02-09 2002-08-20 Showa Engineering Co Ltd 微生物固定化用担体
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JP2004344806A (ja) * 2003-05-23 2004-12-09 Fuji Photo Film Co Ltd 写真廃液の処理方法
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JP2005087860A (ja) * 2003-09-17 2005-04-07 Fuji Photo Film Co Ltd 産業廃棄物処分場の浸出水の処理方法。
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Publication number Priority date Publication date Assignee Title
CN104192986A (zh) * 2014-08-01 2014-12-10 浙江大学 渗流自充氧菌毯短程硝化反应器及其废水处理方法
CN104192986B (zh) * 2014-08-01 2016-01-20 浙江大学 渗流自充氧菌毯短程硝化反应器及其废水处理方法
JP7421708B2 (ja) 2019-11-01 2024-01-25 国立大学法人長岡技術科学大学 微生物担体及び廃液処理方法
CN111439824A (zh) * 2020-03-06 2020-07-24 浙江正洁环境科技有限公司 具有促菌性能的水处理生物膜载体及其制备方法和应用
CN111439824B (zh) * 2020-03-06 2022-08-09 浙江正洁环境科技有限公司 具有促菌性能的水处理生物膜载体及其制备方法和应用

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