WO2007000942A1 - Method for treatment of ammonia-containing wastewater - Google Patents

Method for treatment of ammonia-containing wastewater 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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Prior art keywords
treatment
wastewater
ammonia
nitrogen
cod
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PCT/JP2006/312593
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French (fr)
Japanese (ja)
Inventor
Hideo Miyazaki
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Fujifilm Corporation
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Publication of WO2007000942A1 publication Critical patent/WO2007000942A1/en

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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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Abstract

The invention aims at providing a method for wastewater treatment by which at least the ammonia nitrogen content and chemical oxygen demand (COD) of wastewater can be lowered to levels satisfying the effluent standards under Sewage Water Law. A method for wastewater treatment, characterized by subjecting a wastewater (except liquid wastes from photograph developing) which has COD of 0.3g/L or above and an ammonia nitrogen content of 0.5g/L or above to physicochemical or biological treatment and then treating the resulting wastewater with a treatment comprising ammonia oxidizing bacteria and an inorganic dispersion medium on which the bacteria are inclusively immobilized.

Description

明 細 書  Specification
含アンモニア廃水の処理方法  Ammonia-containing wastewater treatment method
技術分野  Technical field
[0001] 本発明は、含アンモニア廃水の処理方法に関するもので、特に高濃度にアンモ- ァ性窒素を含む廃水やアンモニア性窒素に加えて酸素消費性成分も含む廃水の処 理方法に関するものであり、該処理によって環境負荷の軽減を指向するものである。 背景技術  TECHNICAL FIELD [0001] 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. Background art
[0002] 自然環境及び生活環境の維持のために、生物的酸素要求量 (BOD)、化学的酸 素要求量 (COD)、窒素、リンなどの水質汚染要因に係る成分を含む生活廃水、産 業廃水、農水産業廃水の浄ィ匕が求められている。近年は、富栄養化への影響が大き V、窒素成分の低減が重要な課題となって 、る。とりわけアンモニア性窒素が全窒素 に占める割合が多ぐかつ生活環境からの排出が増大傾向にあるので、その効果的 •経済的な低減手段が求められて 、る。  [0002] In order to maintain the natural environment and living environment, biological oxygen demand (BOD), chemical oxygen demand (COD), domestic wastewater containing components related to water pollution factors such as nitrogen and phosphorus, There is a demand for purification of industrial and agricultural and industrial wastewater. In recent years, the impact on eutrophication has been significant V, and the reduction of nitrogen components has become an important issue. In particular, ammonia nitrogen accounts for a large percentage of total nitrogen, and emissions from the living environment are on the rise. Therefore, there is a need for an effective and economical means of reduction.
[0003] 生活廃水や産業廃水を浄化するための廃水処理方法に関して従来開示されて！、 る方法は、主として生物処理、化学処理及び物理処理である。生物処理法は、例え ば活性汚泥法によるもので、通常廃液を微生物生育環境に適した濃度に希釈 '調整 したものを最適滞留時間となるように曝気処理して COD及び BOD寄与成分並びに 若干の全窒素寄与成分を分解除去する廃水処理方法である。化学処理 (酸化法)は オゾン酸化法、過酸化水素 第一鉄塩法 (フェントン法)、電解酸化法等の化学的な 廃水成分分解除去方法である。物理処理には高圧加熱法、噴霧焼却法、蒸発乾燥 法等がある。廃水中の環境汚染物質の特性は、種々雑多なので、化学処理によって も必ずしも CODの除去率は高くないこともあり、その中には生物処理でも分解され にくい難分解性の成分が含まれることもある。また、物理処理には反応装置の応力腐 食、熱回収のための熱交換器のスケール蓄積、残渣、廃ガス等の処理が高コストとな る廃水ちある。  [0003] Conventionally, 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. Normally, 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.
[0004] そのため 、ずれの手段も単独で排水基準を満たすレベルまで廃水処理するには 不十分なことが多ぐ上記した処理手段の組み合わせ、とりわけ酸化処理と微生物処 理を組み合わせた処理方法が提示されている。例えば、特許文献 1には、写真廃液 に湿式触媒酸化を施した後海洋微生物を用いて生物処理する方法、特許文献 2〖こ は過酸化水素酸化処理 (フェントン法）と微生物処理との組み合わせた処理方法、特 許文献 3には電解酸化処理と微生物処理との組み合わせた処理方法によって、写真 廃液の BOD及び CODの低減できることが開示されている。 [0004] Therefore, a combination of the above-mentioned treatment means, in particular oxidation treatment and microbial treatment, is often insufficient for wastewater treatment to a level satisfying the wastewater standard alone. A processing method combining science is presented. For example, Patent Document 1 describes a method of biological treatment using marine microorganisms after wet catalytic oxidation of photographic waste liquid, and Patent Document 2 is a combination of hydrogen peroxide oxidation treatment (Fenton method) and microorganism treatment. The processing method, 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.
[0005] これらの生物処理、化学処理及び物理処理から選択された組合せ処理は、 BOD や CODなどの酸素消費性についてはかなりの効果は認められる力 全窒素量 (以後 T Nとも記す)の低減作用が特に不十分である。活性汚泥処理などの好気性処理 の場合でも、十分の滞留時間を取れば、処理後期には脱窒が行われるとされている 力 一般的に脱窒反応の進行は極めて緩慢であって、多くの含窒素廃水、とりわけァ ンモニァ性窒素量が大き 、廃水には、実際的でな 、。 [0005] These combined treatments selected from biological treatments, chemical treatments and physical treatments have a significant effect on oxygen consumption such as BOD and COD. Reduction of total nitrogen (hereinafter also referred to as TN) Is particularly inadequate. Even in the case of aerobic treatment such as activated sludge treatment, it is said that denitrification will take place in the later stage of treatment if sufficient residence time is allowed. Generally, the progress of the denitrification reaction is extremely slow. Nitrogen-containing wastewater, especially the amount of ammonia nitrogen is large, and it is not practical for wastewater.
その解決方法として、好気性の生物処理ではなく嫌気性又は好気 ·嫌気組合せの 生物処理も試みられており、例えば特許文献 4には活性炭生物処理と硝化脱窒処理 との組合せ処理、特許文献 5には過酸化水素による化学酸化処理と硝化脱窒処理と の組合せ処理が開示されているが、なお十分満足とはいえず、かつ操作が高度の技 術を要するなどの弱点もある。とくに、好気性硝化が嫌気性脱窒工程の進行に較べ て極めて遅!ヽと ヽぅ問題がある。  As a solution, anaerobic or aerobic / anaerobic combined biological treatment has been attempted instead of aerobic biological treatment. For example, 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.
[0006] その解決手段として、アンモニア性窒素の生物分解過程にアンモニア分解菌（硝 化菌）を担体に固定ィ匕して分解効率を向上させることが提案されている。例えば、特 許文献 6にはアンモニア含有廃水の処理に硝化菌固定ィ匕担体を用 、ることが開示さ れており、特許文献 7及び 8には硝化菌固定化担体処理 (亜硝酸化）と脱窒処理を組 合わせたアンモニア性窒素除去処理を用いることが開示されている。 [0006] As a means for solving this problem, it has been proposed that ammonia-decomposing bacteria (nitrifying bacteria) be immobilized on a carrier during the biodegradation process of ammonia nitrogen to improve the decomposition efficiency. For example, Patent Document 6 discloses the use of a nitrifying bacteria-immobilized carrier for the treatment of ammonia-containing wastewater, and 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.
上記のように廃水中の全窒素、特にアンモニア性窒素を低減除去する実用手段の 開発は精力的に行われてきた力 全窒素、特にアンモニア性窒素濃度が高い廃水 中の場合にも効果的に環境基準や排水基準を満たすレベルまで廃水処理可能な実 際的手段が見出されてなぐさらなる改良が求められている。  As described above, the development of practical means to reduce and remove total nitrogen in wastewater, especially ammonia nitrogen, has been energetically performed. It is effective even in wastewater with high total nitrogen, especially ammonia nitrogen concentration. There is a need for further improvements without finding practical means that can treat wastewater to a level that meets environmental and wastewater standards.
さらに、多くの産業廃水、生活廃水が含窒素成分のみでなく酸素消費成分濃度も 高いことから、全窒素量、特にアンモニア性窒素量の低減にカ卩えて BOD及び COD 並びに全窒素量のいずれをも排水基準値以下に低減させ得る現実的な廃液処理手 段が求められている。 Furthermore, since many industrial and domestic wastewaters have high concentrations of not only nitrogen-containing components but also oxygen-consuming components, BOD and COD can be used to reduce total nitrogen, especially ammonia nitrogen. In addition, there is a need for a realistic waste liquid treatment method that can reduce the total amount of nitrogen below the wastewater standard value.
[0007] この出願の発明に関連する前記の先行技術には、次ぎの文献がある。  [0007] The following documents are related to the prior art related to the invention of this application.
特許文献 1 :特開平 5— 119440号公報  Patent Document 1: JP-A-5-119440
特許文献 2：特開平 3 - 262594号公報  Patent Document 2: JP-A-3-262594
特許文献 3：特開平 4 235786号公報  Patent Document 3: Japanese Patent Laid-Open No. 4235786
特許文献 4：特開平 9— 85291号公報  Patent Document 4: JP-A-9-85291
特許文献 5：特開平 9 - 94597号公報  Patent Document 5: Japanese Patent Laid-Open No. 9-94597
特許文献 6：特開平 9—47788号公報  Patent Document 6: Japanese Patent Laid-Open No. 9-47788
特許文献 7：特開平 9 - 75984号公報  Patent Document 7: JP-A-9-75984
特許文献 8：特開 2001— 170684号公報  Patent Document 8: Japanese Patent Laid-Open No. 2001-170684
発明の開示  Disclosure of the invention
発明が解決しょうとする課題  Problems to be solved by the invention
[0008] 本発明は、上記した背景力もなされたものであり、その目的は、廃水中の少なくとも アンモニア性窒素量を下水道法に基づく排水基準を満たすレベルに低減できる廃 水処理方法を提示することにあり、より大きい目的は廃水中の全窒素量及びアンモニ ァ性窒素量を下水道法に基づく排水基準を満たすレベルに低減できる廃水処理方 法を提示することにあり、さらなる目的は BOD及び COD並びに全窒素量のいずれを も下水道法に基づく排水基準を満たすレベルに低減できる廃水処理方法を提示す ることである。 [0008] 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.
本発明の別の観点力もの目的は、全窒素量及び Z又はアンモニア性窒素量が高 Another objective of the present invention is that the total amount of nitrogen and the amount of Z or ammonia nitrogen are high.
V、廃水 (好気性処理の滞留時間の延長では対応できな!/、ような）に対しても上記課 題を達成することができる手段を提示することである。 V, suggesting a means to achieve the above problem even for wastewater (such as cannot be handled by extending the residence time of aerobic treatment! /).
課題を解決するための手段  Means for solving the problem
[0009] 本発明者は、上記目的の解決方法を見出すために、とくにアンモニア酸ィ匕細菌 (硝 化菌)の棲息環境と硝化活性との関連に着目して鋭意検討したところ、アンモニア酸 化細菌は、無機分散体と包括固定化体の中に共存した状態に置かれると、硝化活性 が顕著に向上するという現象が見出され、この発見に基づいてさらに検討を進めて 本発明に到達することができた。すなわち、本発明は以下の通りである。 [0009] In order to find a solution for the above-mentioned object, 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.
[0010] (1)化学的酸素要求量 (COD)が 0. 3gZL以上でかつアンモニア性窒素量が 0. 5g ZL以上である、写真処理廃水以外の廃水を、物理化学的に又は生物学的に処理 したのちアンモニア酸ィ匕細菌と無機物分散体とを含有する包括固定体により処理す ることを特徴とする廃水処理方法。  [0010] (1) Physicochemical or biological wastewater other than photographic processing wastewater having a chemical oxygen demand (COD) of 0.3 gZL or more and an ammoniacal nitrogen amount of 0.5 g ZL or more A wastewater treatment method comprising: treating with a entrapping immobilization body containing ammonia acid bacteria and an inorganic dispersion.
(2)物理化学的処理が導電性ダイヤモンド電極を陽極として用いる電解酸化処理で あることを特徴とする上記（1)に記載の廃水処理方法。  (2) The wastewater treatment method as described in (1) above, wherein the physicochemical treatment is an electrolytic oxidation treatment using a conductive diamond electrode as an anode.
(3)無機物分散体が炭素、酸化アルミニウム、酸化ケィ素から選択される少なくとも 1 種を主成分とする無機物分散体であることを特徴とする上記（1)又は（2)に記載の廃 水処理方法。  (3) The wastewater as described in (1) or (2) above, wherein the inorganic dispersion is an inorganic dispersion mainly composed of at least one selected from carbon, aluminum oxide and silicon oxide. Processing method.
(4)アンモニア酸ィ匕細菌の包括固定体が該細菌をポリビュルアルコール (PVA)を主 体としたゲルに包括した包括固定体であることを特徴とする上記（1)〜（3)の 、ずれ かに記載の廃水処理方法。  (4) 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. The wastewater treatment method described in any one of the above.
[0011] 本発明の廃水処理方法の特徴は、アンモニア酸ィ匕細菌と無機物分散体とを共存さ せた包括固定体を用いる条件下でアンモニア性窒素を分解除去させることにある。 生分解菌を包括固定させて生分解効率を向上させる方法は知られているが、無機分 散体をアンモニア酸化細菌と共存させた包括固定体分散系によると分解効率が顕著 に向上し、かつアンモニア性窒素濃度 (T—N)が 0. 5gZL以上という高濃度でも効 果的にアンモニア分解が進行することが今回見出された特異効果であって、この現 象を利用することによって本発明の課題を達成することが可能となった。本発明は、 高アンモニア性窒素含有するいずれの廃水にも適用できるが、写真廃液以外の廃 水、すなわち海洋性菌などの好塩性菌を適用できない廃水、に対して用いることが 効果的である。  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. There is known a method for improving the biodegradation efficiency by entrapping and fixing biodegradable bacteria. However, the degradation efficiency is significantly improved by the entrapped fixed body dispersion system in which the inorganic dispersion coexists with ammonia-oxidizing bacteria. This is a unique effect that was found this time that ammonia decomposition proceeds effectively even when the ammoniacal nitrogen concentration (T—N) is as high as 0.5 gZL or higher. It has become possible to achieve these issues. 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.
本発明のアンモニア性窒素低減処理方法は、上記のアンモニア性窒素分解除去 工程の前段として物理ィ匕学的又は生物学的処理を設けるが、この前段処理とアンモ ニァ酸化細菌で処理との組合わせ効果によって処理される廃水が化学的酸素要求 量 (COD)も高ぐかつアンモニア性窒素も含めた全窒素成分も高い廃液であても効 果が大きい。例えば、化学的酸素要求量 (COD)が 0. 3gZL以上でアンモニア性窒 素量が 0. 5gZL以上の廃水に対して CODとアンモニア性窒素量をともに十分な低 レベルまで低減することができる。 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.
そのようなアンモニア性窒素量低減処理に組合わせる COD低減処理としては物理 化学的処理又は生物学的処理 (生物処理）が好ましぐ中でも電解酸化処理が好ま しぐとりわけダイヤモンド電極を用いる電解酸ィ匕処理力 SCODとアンモニア性窒素量 の ヽずれをも顕著に低減できる点で優れた廃水処理方法と言える。導電性ダイヤモ ンド電極を陽極とする電解酸化処理は、酸素消費量の低減効果にお！ヽて他の陽極 による酸化処理よりも優れているが、特に特徴的なのは電解酸化処理を経た残存全 窒素量寄与成分は微生物処理によって分解され易くなつていて窒素除去効率が向 上することである。それによつて廃水の BOD及び COD並びに全窒素量 (T—N)、ァ ンモニァ性窒素量のいずれをも下水道法に基づく排水基準を満たすレベルに低減 可能となる。  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.
微生物による全窒素量低減処理には、公知の脱硝'脱窒微生物が用いられるが、 とくにアンモニア酸ィ匕細菌 (硝化菌）を担体に固定ィ匕することによって生物活性が向 上する。  Known denitration and denitrification microorganisms are used for the treatment of reducing the total amount of nitrogen by microorganisms. In particular, the biological activity is improved by fixing ammonia acid bacteria (nitrifying bacteria) on a carrier.
本発明の廃水処理方法の別の特徴は、比較的高アンモニア性窒素量の廃液を処 理できるので、電解処理後に微生物による全窒素量低減処理を行う際に、水希釈す ることなく、あるいは比較的低希釈倍率で処理が可能なことであり、したがって広い処 理スペースを必要とせず、設備も小型化できることである。  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.
なお、本発明の対象となる廃水としては、 BOD及び COD並びにアンモニア性窒素 や全窒素を含む 、ずれの廃水であってもよ!/、が、写真処理廃水には適用されな!、。 写真処理廃水は、概して高塩濃度である点で、本発明の適用対象から除外される。 発明の効果  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
物理化学的処理や生物処理と無機物分散体とアンモニア酸化細菌の包括固定体 の共存下での窒素低減処理とを組合わせて処理することを特徴とする本発明の廃液 処理方法は、 0. 5gZL以上という高濃度のアンモニア性窒素を含有する廃水を排 水基準を満たす低レベルまで分解除去することができる。また、多くの全窒素量 (T— N)の高い廃水に対しても同様の効果がある。さらには、アンモニア性窒素に加えて 酸素消費成分も含む廃水でも BOD及び COD並びに T Nのいずれをも下水道法 に基づく排水基準を満たすレベルに低減できる。 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.
発明を実施するための最良の形態  BEST MODE FOR CARRYING OUT THE INVENTION
[0013] 以下、本発明をさらに具体的に詳述する。 [0013] Hereinafter, the present invention will be described in more detail.
なお、本明細書では生分解に係る「微生物」を「菌体」と呼ぶこともあるが、実質的に 同義に解してよい。  In this specification, “microorganism” related to biodegradation may be called “bacteria”, but may be understood substantially synonymously.
[0014] [被処理廃水] [0014] [Treatment wastewater]
本発明の実施の形態の説明に先だって、発明の対象である廃水について述べる。 本発明は、アンモニア性窒素量が高い廃水の処理に適している。ここにいう「アンモ ニァ性窒素量」は、水質汚濁防止法に係る排水基準に係る「アンモニア性窒素量」を 指す。  Prior to the description of the embodiments of the present invention, the wastewater that is the subject of the invention will be described. 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.
近年は、富栄養化への影響が大き 、窒素成分の低減が重要な課題となって 、て地 域水質規制の強化も行われている。とりわけアンモニア性窒素が全窒素に占める割 合が多ぐかつ生活環境力 の排出が増大傾向にあるので、その効果的'経済的な 低減手段が求められている。  In recent years, the impact on eutrophication has been significant, reducing nitrogen content has become an important issue, and regional water quality regulations have been strengthened. In particular, ammonia nitrogen accounts for a large percentage of total nitrogen and the emission of living environment power is increasing. Therefore, an effective and economical means of reducing the demand is required.
高アンモニア性窒素廃水としては、自家処理槽残渣由来の生活廃水、あるいは嫌 気性し尿処理残渣やその抽出水などの生活環境廃水、ボイラー灌水、化学工場廃 水、食品加工工場廃水などの産業廃水、農産，水産、畜産業由来の廃水など多岐 にわたつており、これらが本発明の廃水処理方法の適用対象である。  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. 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.
本発明の廃水処理方法は、高濃度のアンモニア性窒素含有廃水に適しており、ァ ンモユア性窒素量が 0. 5gZL以上、 8gZL未満、好ましくは 0. 5gZL以上、 7gZL 未満、より好ましくは 0. 5gZL以上、 6gZL未満の廃水に適用される。しかしながら、 本発明の廃水処理方法は、高アンモニア性窒素廃水に限定されない。  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. However, the wastewater treatment method of the present invention is not limited to high ammonia nitrogen wastewater.
本発明は、アンモニア性窒素や全窒素と COD寄与成分をともに含有する廃水に対 して好ましく適用でき、アンモニア性窒素、全窒素、 COD寄与成分のいずれをも効 果的に低減できる。  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.
本発明の廃水処理方法は、前段に生物処理又は物理化学的処理、とりわけ電気化 学的処理を行!、、次 、で後段のアンモニア性窒素分低減のための硝化脱窒処理を 組合わせるので、特に高濃度の廃水の場合は、アンモニア性窒素量が上記の範囲 に入るように水希釈などの前調整が行われるのが好ま 、。 In the wastewater treatment method of the present invention, 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. Because of the combination, especially in the case of highly concentrated wastewater, it is preferable to make preconditioning such as water dilution so that the amount of ammoniacal nitrogen falls within the above range.
[0015] 本明細書における廃水の COD、全窒素量、アンモニア性窒素などは、通常の水質 環境指標として用いられる特性項目であって、 JIS K0102 (工業排水試験方法）に規 定された COD 、全窒素量、アンモニア性窒素の試験方法にもとづ 、て 、る。 [0015] 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.
Mn  Mn
[0016] [廃液処理工程]  [0016] [Waste liquid treatment process]
<硝化脱窒処理 >  <Nitrification denitrification treatment>
硝化脱窒処理について、説明する。廃水中にアンモニア、亜硝酸、硝酸等の無機 窒素化合物を含む場合には、生物学的に窒素除去を行うことができる。亜硝酸、硝 酸は、嫌気性条件下で脱窒菌により窒素となって除去される。アンモニアの場合は、 まず硝化が必要で、硝化は亜硝酸化と硝酸化に分けられる。亜硝酸化は、亜硝酸菌 (Nitrosomonas)によりなされ、硝酸化は硝酸菌（Nitrobactor)によりなされる。亜硝酸 菌と硝酸菌は総称して硝化菌と呼ばれる。硝化菌は増殖速度が小さいので処理槽 内の菌体濃度を高めるためには、硝化菌の流出が起こらな 、ようにする必要がある。 そのためには、例えば、 SRT (汚泥滞留時間）を長く保持したり、付着担体に硝化菌 を付着させて固定ィ匕したり、硝化菌を包括固定化させたり、包括固定化させたペレツ トによって処理槽内の硝化菌濃度を高めたりする方法が挙げられるが、本発明にお いては、硝化菌を無機物分散体と共存させ包括固定化した分散系にお!、て廃水処 理を行うのが特徴である。  The nitrification denitrification process will be described. When 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. In the case of ammonia, nitrification is required first, and nitrification is divided into nitritation and nitrification. Nitrite is performed by nitrite (Nitrosomonas), and nitrification is performed by nitrite (Nitrobactor). Nitrite bacteria and nitrate bacteria are collectively called nitrifying bacteria. Since 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.
この硝化菌 ·無機物分散体組合わせ処理によって従来の硝化脱窒処理に比較して 顕著な硝化脱窒効果が得られる。  This combined nitrifying / inorganic dispersion treatment can provide a significant nitrifying / denitrifying effect compared to the conventional nitrifying / denitrifying treatment.
[0017] 硝化菌を増殖させるための条件としては、水温、 pH、溶存酸素， BOD負荷などが ある力 特に重要な因子は pHであり pH6. 5〜8. 5が好ましい。  [0017] As conditions for growing nitrifying bacteria, water temperature, pH, dissolved oxygen, BOD loading, etc. Particularly important factors are pH, and pH 6.5 to 8.5 is preferable.
[0018] 硝酸、亜硝酸を嫌気条件で脱窒菌により脱窒するためには、水素供与体としての 有機化合物 (有機炭素源)が必要である。有機炭素源として原水中の有機物の利用 が可能であるが、不足する場合にはメタノール、酢酸等を添加する方法がとられてい る。メタノールの場合には、実用的には硝酸性窒素 (NO -N) lKgに対して BOD換  [0018] In order to denitrify nitric acid and nitrous acid by denitrifying bacteria under anaerobic conditions, an organic compound (organic carbon source) as a hydrogen donor is required. Although organic substances in raw water can be used as the organic carbon source, methanol, acetic acid, etc. are added if insufficient. In the case of methanol, POD is practically converted to nitrate nitrogen (NO -N) lKg.
3  Three
算で約 3倍量のメタノールの添カ卩が必要である。 [0019] また、脱窒菌として Thiobacillus denitrificansのようなィォゥ脱窒細菌を用いても ょ 、。ィォゥ脱窒細菌は硝酸塩ある 、は亜硝酸塩を電子受容体として還元し窒素ガ スにする一方、元素状ィォゥゃチォ硫酸を電子供与体として酸化して硫酸塩にする 。従って、ィォゥ、チォ硫酸塩を脱窒に用いることができるので、メタノール等の有機 薬品を使用しない安価な脱窒処理を行うことも可能である。 In total, about 3 times the amount of methanol needs to be added. [0019] Further, 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.
[0020] これらの生物処理のより具体的な方法、用語の意味の解説については「生物学的 水処理技術と装置」化学工学協会編 (培風館)、「環境浄化のための微生物学」須藤 隆ー編 (講談社サイェンティフイク）、「廃水処理プロセス、設計理論と実験法」 W. W .エッケンフェルダー、 D. L.フォード著 (技報堂)などに記載されている。  [0020] For more specific methods and terminology of these biological treatments, see “Biological Water Treatment Technology and Equipment”, Chemical Engineering Association (Baifukan), “Microbiology for Environmental Purification”, Takashi Sudo -Ed (Kodansha Scientific), "Wastewater Treatment Process, Design Theory and Experimental Method" W. W. Eckenfelder, DL Ford (Gihodo) and others.
[0021] 硝化細菌を包括固定ィ匕した分散体と共存させる無機分散体としては、アルミナなど の酸ィ匕アルミニウムを主成分とする無機粒子、多孔質シリカ、コロイダルシリカ、シリカ ゲル、焼却飛灰などの酸ィ匕ケィ素単体粒子、多孔性セラミタス、活性炭、骨炭や木炭 などの炭素単体粒子、カオリナイト、モンモリロナイトなどの粘土鉱物、活性白土、合 成又は天然ゼォライト、アンスラサイト、砂利、砂、軽石、珪藻土等の 1種または 2種以 上を用いることができる。  [0021] 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.
好まし 、無機分散体は、アルミナなどの酸ィ匕アルミニウムを主成分とする無機粒子 、多孔質シリカ、コロイダルシリカ、シリカゲル、焼却飛灰などの酸化ケィ素単体粒子 、活性炭、骨炭や木炭などの炭素単体粒子であり、中でもアルミナ、シリカゲル、焼却 飛灰、活性炭が好ましい。  Preferably, 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.
[0022] 担体粒子の大きさは、外径 0. l〜70mm、好ましくは 0. 5〜40mm、より好ましくは  [0022] The carrier particles have an outer diameter of 0.1 to 70 mm, preferably 0.5 to 40 mm, more preferably
1. 0〜20mmであり、粒子サイズが大きければ比面積が少なくなつて非効率となり、 小さいとすぐに分解 '消滅して担持体の意味をなさなくなる。したがって、適用対象 に応じて好ま 、サイズが選択される。  1. It is 0 to 20 mm, and if the particle size is large, the specific area decreases and becomes inefficient. If it is small, it decomposes and disappears as soon as it becomes meaningless. Therefore, the size is selected according to the application target.
[0023] 無機分散体の形状は、任意であるが、多孔質のもの、比面が大きいものが好ましい  [0023] The shape of the inorganic dispersion is arbitrary, but a porous one and a large specific surface are preferable.
[0024] 包括固定ィ匕法の特徴は、菌体を高濃度に保持できるため、処理効率を向上させる ことができ、増殖の遅い菌を固定ィ匕できる。また、 pH、温度等の条件変化に対する耐 性が広ぐ高負荷状態にも耐えることができる。包括固定化法としては、アクリルアミド 法、寒天 アクリルアミド法、 PVA ホウ酸法、 PVA 冷凍法、光硬化性榭脂法、ァ クリル系合成高分子榭脂法、ポリアクリル酸ソーダ法、アルギン酸ナトリウム法、 K—力 ラギーナン法等、微生物を閉じ込めることができ、系の中で微生物の活性を維持しつ つ、物理的強度が大きく長時間の使用に耐え得るものならば種類を問わない。 [0024] 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. As 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.
[0025] 包括固定ィ匕法の代表例としてアクリルアミド法の場合の微生物固定ィ匕ゲルの調製 法について説明する。固定ィ匕ゲルは、架橋剤（例えば、 N, N'—メチレンビスアクリル アミド）を含有したアクリルアミドモノマー溶液と細菌（MLSS 20, OOOppm程度の濃 縮菌体）とを懸濁し、重合促進剤（例えば、 N, N, Ν' , N'—テトラメチルエチレンジ ァミン）、重合開始剤（例えば、過硫酸カリウム）を添加し、 3mm径の塩化ビュル製チ ユーブ等の成型形に入れ、 20°Cで重合し、重合終了後、成型形力 押し出し、一定 の長さに切断して得られる。固定ィ匕ゲルの表面の細孔は、細菌より小さいため、包括 固定ィ匕した細菌はリークしにくぐ内部で増殖し、自己分解する。廃液中の汚染成分 のみが細孔よりゲル内部に入り込み、内部の細菌により処理される。  [0025] 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, Ν ', 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. Since the pores on the surface of the immobilized gel are smaller than the bacteria, 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.
[0026] 硝化菌の包括固定ィ匕には、 PVA法、アクリルアミド法等が好ましい。これらの固定 化のより具体的な方法については先に示した文献に記載されている。これらの処理 は連続式であっても回分式であってもよい。  [0026] 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.
[0027] 窒素、リン酸等の栄養塩は通常添加する必要はないが、特にリンが不足する場合 は加える必要がある。  [0027] 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.
[0028] 硝化工程において、温度は 20〜35°Cが好ましぐ 30〜35°Cが更に好ましい。 pH は 6. 5〜8. 5力 子ましく、 7. 0〜8. 0が更に好ましい。処理時間は処理方法、被処 理液中のアンモニア濃度、 目標とする処理レベルによって異なる力 1〜5日が好ま しぐ 1〜3日がより好ましい。処理の負荷としては、窒素負荷 0. 2〜0. 7kg-N/ (m 3·日）が好ましい。  [0028] In the nitrification step, 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).
[0029] 硝化工程後の脱窒工程は、硝化工程の直後でもよ!/、し、何らかの処理をした後で もよい。また、脱窒工程は硝化工程より前に設けて、硝化工程処理液を脱窒工程に 返送してもよ!/ヽ。脱窒工程は嫌気的雰囲気（曝気をせずに処理する方法)で行われ、 容易に脱窒が進行する。脱窒工程に用いる水素供与体としてはメタノール、プロパノ ール、酢酸等の有機化合物、生物処理汚泥、チォ硫酸塩等を用いることができる。ま た、電解工程後に残存する有機物を脱窒に用いることもでき、通常脱窒に用いられる メタノール等の有機化合物の量を節減することができ、脱窒にかかる薬品コストを大 巾に節減できる。この場合、脱窒工程は電解工程直後に設けて、後の硝化工程の処 理液を返送する方式となる。硝化工程からの返送量は第 1工程カゝら脱窒工程への流 入量の 1〜4倍が好ましく 2〜3倍がより好ましい。返送量が多すぎると、返送用ポンプ 動力のコストが高くなつたり、硝化工程力 脱窒槽への溶存酸素の持ち込みにより脱 窒効率の低下の原因になったりするので好ましくない。 [0029] 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. As the hydrogen donor used in the denitrification step, organic compounds such as methanol, propanol and acetic acid, biologically treated sludge, thiosulfate and the like can be used. Ma In addition, organic substances remaining after the electrolysis step can be used for denitrification, and the amount of organic compounds such as methanol usually used for denitrification can be reduced, and the chemical cost for denitrification can be greatly reduced. In this case, 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.
[0030] 脱窒工程に用いる生物処理方法とは、活性汚泥法、三相流動層法、スポンジ担体 法等の微生物浮遊懸濁法、生物濾過法、浸漬ろ床法、流動床法等の生物膜法、包 括固定法等を用いることができるがこれらの方法の中で、微生物浮遊懸濁法と生物 膜法が好ましぐ生物膜法の中でも、浸漬ろ床法、粒状担体を用いた生物ろか法、流 動床法等が好ましい。脱窒工程に活性炭を用いて、脱窒工程と被処理廃液の好気 的生物処理後の難分解性物質の分解を兼ねることも可能である。脱窒のための水素 供与体として加えた有機化合物が存在するので、難分解性物質の分解にはコメタボ リズム条件かつ嫌気性条件での処理となり、好ましい。脱窒工程で残存する COD成 分を除去するため、脱窒工程の後に好気処理をすることが好ましい。好気処理に用 いる生物処理としては、活性汚泥法、三相流動層法、スポンジ担体法等の微生物浮 遊懸濁法、生物濾過法、浸漬ろ床法、流動床法等の生物膜法等を用いることができ る力 これらの方法の中で、生物膜法が好ましい。脱窒工程に活性炭を用いて脱窒と 廃液の好気的生物処理後の難分解性物質の分解を同時に行なう場合、脱窒工程後 の好気処理としては、難分解性物質の分解を更に充分に行わせる  [0030] 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. By using 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. Since there is an organic compound added as a hydrogen donor for denitrification, the decomposition of the hardly decomposable substance is preferably a treatment under cometabolism conditions and anaerobic conditions. 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. When using activated carbon in the denitrification process to simultaneously perform denitrification and decomposition of the hardly decomposable substance after the aerobic biological treatment of the waste liquid, the aerobic treatment after the denitrification process can be further decomposed Let it do enough
[0031] 以上の処理工程の後には必要に応じて、鉄成分およびリンの除去を行うことが好ま しい。鉄成分についてはその大部分が、電解酸ィ匕工程において不溶分として除去さ れる。更に鉄除去が必要な場合は、処理液をアルカリ性にして鉄イオンを不溶ィ匕し除 去したり、 pH4〜7. 5で鉄イオンをリン酸塩及び Zまたは他の無機塩'酸との複合塩 として沈澱除去する方法などが挙げられ、これらについては、特開平 4 235787号 等に記述されている。  [0031] After the above treatment steps, it is preferable to remove the iron component and phosphorus 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.
[0032] リン除去については、物理化学的処理方法が好ましぐ例えば石灰凝集沈澱法、ァ ルミ-ゥム凝集沈澱法、鉄凝集沈澱法、種結晶としてリン鉱石、骨灰、マグネシアタリ ンカ、アパタイト等を用いた晶析法、活性アルミナ、キレート榭脂等を用いた吸着法、 鉄接触を用いる方法、イオン交換法等を用いることができる。これらの方法について は「脱窒 '脱燐技術と高栄養化」（アイピーシー）に詳しく記載されている。 [0032] For phosphorus removal, physicochemical treatment methods are preferred, 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).
[0033] 本発明の廃水処理方法の対象となる廃水が、高い COD値を有する場合は、 COD 値低減を主目的とする生物処理又は物理化学的処理を硝化脱窒を主目的とする無 機分散体共存包括固定化菌による硝化脱窒処理と組合わせて行う。  [0033] When the wastewater to be treated by the wastewater treatment method of the present invention has a high COD value, 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.
[0034] <物理化学的酸化処理 > [0034] <Physicochemical oxidation treatment>
本明細書において、物理化学的酸化処理は、化学酸化処理の中で、酸化剤が処 理済み廃液中に水、酸素、水素、炭酸ガス又は炭酸イオン以外の反応生成物として 残ることのない処理を指す。具体的には、酸素、オゾン、過酸化水素、過炭酸から選 択される酸化剤による酸化処理、これらの酸化剤存在下での紫外線などの活性光照 射処理、電解酸化処理、及び活性光照射を伴う電解酸化処理が挙げられる。  In this specification, 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. Point to. Specifically, 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. And electrolytic oxidation treatment with
好ましい物理化学的酸化処理は、電解酸化処理、オゾン酸化処理、過酸化水素酸 化処理、及びこれらと紫外線照射の組み合わせ処理であるが、本発明に特に好まし い処理は、電解酸化処理である。  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. .
[0035] <電解酸化処理 > [0035] <Electrolytic oxidation treatment>
本発明において、廃水は、必要があれば電解酸化処理に先だって又は電解中に 水酸化ナトリウム、水酸ィ匕カリウム、水酸ィ匕カルシウム、炭酸ナトリウムなどのアルカリ 剤を用いて pHの調整を行ってもよい。また、不溶性沈澱物 (浮遊物）となり易い鉄化 合物を含有する廃液の場合は濾過や沈降操作によって除去しておくことが好ましい 。さらに CODの分解効率を高い水準に維持するためにもアルカリ性の pHが好ましい 1S 添加されるアルカリ剤は、固体、水溶液、懸濁液などのいずれの形であってもよく 、添加方法も電解酸ィ匕処理に先だって添加してもよぐまた自動調整装置と連動させ ながら電解をすすめてもよい。 pHは電解操作中 7以上に、好ましくは pH8以上に、 維持されるように調整されてもょ 、。  In the present invention, if necessary, 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. Further, in the case of a waste liquid containing an iron compound that easily becomes an insoluble precipitate (floating matter), it is preferably removed by filtration or sedimentation. Further, in order to maintain the decomposition efficiency of COD at a high level, alkaline pH is preferable. 1S 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.
一方、鉄錯塩ィ匕合物の加水分解による沈殿生成を抑止するために、 pHは 12. 5以 下であることが好ましい。 [0036] 電解酸化処理の温度は常温或いはこれよりやや高い温度が好ましぐまた、電圧は 5.0〜8.0 V、電流密度は、 0.0O5〜lA/cm2が好ましぐより好ましくは 0.Ο1〜0.5 A /cm2がよい。また、電解は回分法でも連続法の何れでもよい。 On the other hand, the pH is preferably 12.5 or less in order to suppress precipitation formation due to hydrolysis of the iron complex salt compound. [0036] Temperature of the electrolytic oxidation treatment room temperature or a temperature slightly higher than this was Sigma preferred, voltage is 5.0 to 8.0 V, the current density is preferably from preferably tool is 0.0O5~lA / cm 2 0.Ο1 good ~0.5 a / cm 2. The electrolysis may be either a batch method or a continuous method.
電解酸化処理の程度にもよるが、好ま 、条件ではこのプロセスによって廃液中の CODの 10〜6O%、多くの場合 20〜50%が低減される。しかしながら、電解酸化処 理の大きな利点は、 CODの低減効果以上に、前記したように電解酸化処理済み液 中に残存する全窒素量寄与成分が微生物処理によって除去され易 、性質の窒素化 合物となっていることであり、これによつて全窒素量の低減率が向上することある。  Depending on the extent of the electrolytic oxidation treatment, this process preferably reduces the COD in the effluent by 10-6O%, often 20-50%, depending on the degree of electrolytic oxidation. However, 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.
[0037] 電解槽は腐食に耐える耐食性材料である白金、フェライト、ステンレス、酸化皮膜が 速やかに形成される鉄等から選択することが好ましい。陰極は電子供与極であり、電 解酸ィ匕反応には直接関与しないが、反応液に対して不活性な材質である白金、ステ ンレス等が好ましい。例えば、陽極にはフェライト電極を、陰極にはステンレス電極等 が好ましい。また、廃水中に懸濁成分が含まれていることもあるため、電極への懸濁 物の沈澱を防止して均一な酸ィ匕反応を起こさせ、電流効率を高めるためには回転陰 極が好ましい。  [0037] 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. For example, a ferrite electrode is preferable for the anode, and a stainless electrode or the like is preferable for the cathode. In addition, since suspended components may be contained in the wastewater, 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.
[0038] 電解酸ィ匕に用いる陽極として通常用いられるのは、二酸化鉛、炭素（グラフアイト、 グラシ一力一ボンなど）、鉄、ステンレス、ニッケルなどの公知の陽極である力 本発 明では、導電性ダイヤモンド電極を使用する。これによつて廃液中の難分解性物質 の電気分解を効率良く行でき、とくに全窒素量寄与物質が処理済み液に残存しても 生物処理を受け易!、性質となって!/、る。本発明にお 、て"導電性ダイヤモンド電極" とは 1M Ω cm未満の電気抵抗率を有するダイヤモンド電極を意味するが、誤解の恐 れのない限り"導電性"を省略して記すこともある。  [0038] As the anode used for the electrolytic acid, 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. Use 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! . In the present invention, the term “conductive diamond electrode” means a diamond electrode having an electrical resistivity of less than 1 MΩcm, but “conductive” may be omitted as long as there is no fear of misunderstanding. .
[0039] 陽極用電極物質であるダイヤモンドは、粉末ダイヤモンドを基板であるチタン、 -ォ ブ、タンタル、シリコン、カーボン、ニッケル、タングステンカーバイド等の板、打抜き板 、金網、粉末焼結体、金属繊維焼結体等の表面に後述の方法により被覆して電極を 構成してもよぐまた板状のダイヤモンドをそのまま電極として使用しても良いが、コス ト面カも前者を採用することが望ましい。前者におけるダイヤモンド被覆層を本明細 書では、ダイヤモンド層と記す。又密着性の確保と基体の保護とを目的として基体と ダイヤモンド層の間に中間層を設けることが好まし 、。中間層の材質としては基体を 構成する金属の炭化物や酸化物が使用できる。基体表面は密着性と反応面積増大 に寄与するため研磨しても良いし、逆に粗にしてもよい。又電極物質としてダイヤモ ンド以外に少量の他の電極物質を含有して!/、ても良 、。 [0039] 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. . In the present specification, the diamond coating layer in the former is referred to as a diamond layer. For the purpose of ensuring adhesion and protecting the substrate, It is preferable to provide an intermediate layer between the diamond layers. As 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. In addition to diamond, the electrode material may contain a small amount of other electrode materials!
[0040] ダイヤモンド層の基板表面への形成方法としては、熱フィラメント CVD法、マイクロ 波プラズマ CVD法、プラズマアークジェット法、 PVD法などが開発されている。次に 代表的な熱フィラメント CVD法にっ 、て説明する。炭素源となるアルコールなどの有 機化合物を水素ガス中等の還元雰囲気に保ち、炭素ラジカルが生成する温度 1800 〜2400°Cに維持する。このとき電極基体を、ダイヤモンドが析出する別の温度（750 〜950 °C)領域に設置する。水素に対する好ましい有機化合物ガス濃度は 0.1 〜10 容量％、供給速度は反応容器の寸法にも依るが 0.01〜10リットル Z分、圧力は 15〜7 60 mmHgである。ダイヤモンド微細粒子は通常 0.01〜5 μ m程度の粒径を有し、本 発明では前記条件により前記基体上にダイヤモンド粉末を蒸着させて、厚さ 0.1 〜50 μ m好ましくは 1〜10 μ mの厚さのダイヤモンド層とする。この厚さは基体への電解液 の浸入を防ぐために好適な厚さである。生成するダイヤモンド層に良好な導電性を 付与するためには原子価の異なる元素を微量添カ卩（ドーピング)することが必要で、 例えばリンや硼素を l〜100000ppm、好ましくは 100〜10000 ppm程度含有させる。 この添加物の原料ィ匕合物としては毒性の少ない酸ィ匕硼素や五酸ィ匕ニリンなどが好ま しい。  [0040] 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. Next, a typical hot filament CVD method will be described. Keep organic compounds such as alcohol as a carbon source in a reducing atmosphere such as hydrogen gas, and maintain the temperature at which carbon radicals are generated at 1800-2400 ° C. At this time, 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 μm. In the present invention, diamond powder is deposited on the substrate according to the above conditions to have a thickness of 0.1 to 50 μm, preferably 1 to 10 μm. A thick diamond layer. This thickness is suitable for preventing the electrolyte from entering the substrate. In order to give good conductivity to the diamond layer to be formed, it is necessary to add a trace amount of elements having different valences (doping). For example, phosphorus or boron is l to 100,000 ppm, preferably about 100 to 10,000 ppm. Contain. As the raw material of this additive, a compound having low toxicity such as acid boron or pentanoic acid aniline is preferable.
[0041] 十分な電導性を付与するためのドーピングには、プラズマ増強 CVD (PECVD)ダ ィャモンド蒸着法を利用することが好まし 、。ドーピングされた電極の製作方法の詳 細は、例えば、 Ramesham, Thin Solid Films 、 229卷（1993) 44〜50頁に記載されて いる。 PECVDダイヤモンド層は、マイクロ波プラズマにより活性化したメタン及び水 素ガスの混合物力も製造したホウ素ドーピングィ匕多結晶質ダイヤモンドである。この 方法によるダイヤモンド層の蒸着は当業者によく理解されている（例えば、 Klages, Ap pl.Phys. A56卷（1993) 、 513〜526頁を参照）。  [0041] For doping for imparting sufficient electrical conductivity, it is preferable to use a plasma enhanced CVD (PECVD) diamond deposition method. Details of the method of manufacturing the doped electrode are described, for example, in Ramesham, Thin Solid Films, 229 (1993), pages 44-50. 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 卷 (1993), pages 513-526).
[0042] 熱フィラメント CVD (HFCVD)法（Klages, Appl.Phys. A56卷（1993) 513〜526頁を 参照）により製造したダイヤモンド層は、 Advanced Technology Materials. In ， 7 Co mmerce Drive, Danbury.CT 06810、米国から市販されている。 [0042] Diamond layers produced by the hot filament CVD (HFCVD) method (see Klages, Appl. Phys. A56 卷 (1993) pp. 513-526) are based on Advanced Technology Materials. In, 7 Co mmerce Drive, Danbury. CT 06810, commercially available from the United States.
ダイヤモンド電極の製法としては、特開平 8-225395号公報段落 0007に記載されて V、る真空チャンバ一内での化学蒸着法も好ま 、。  As a method for producing the diamond electrode, the chemical vapor deposition method described in paragraph 0007 of JP-A-8-225395 is also preferred.
[0043] 電解酸ィ匕用の陰極としては、電解の休止期間中に腐食を起こさないよう十分の耐 蝕性と通電性を持つものなら!/、ずれの材料でもよ!/、が、ステンレスの板又は棒が特に 適している。しかし、他の電極、例えば炭素電極や種々の金属電極も使用できる。陰 極 ·陽極を対にした形、陰極を両側力 陽極が挟むサンドイッチ構造の形、あるいは 陰極と陽極とを交互に配した多数枚配列構造などの適切な形が選択される。陰極の 形状は、線状、棒状、板状などのいずれであってもよい。  [0043] As 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. However, 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.
[0044] また、本発明の一態様として、陰極にも導電性ダイヤモンド電極を用いることができ る。また、両極に導電性ダイヤモンド電極を用いる場合には、極性を反転させながら 電解を行うことも電極を正常な状態に維持するために好ましい。すなわち、電解槽の 陰極面上には、カルシウムイオンやマグネシウムイオンの水酸ィ匕物等が付着するた め、定期的なスケール除去が必要である。スケールの付着を防止するために、電極 の極性をごく短時間反転する考案 (特開平 3-109988号、特開平 5-4087、特開平 6- 63558等）が報告されている。これらの方法を用いると、電解槽の陰極面上に付着物 を、電極の極性を逆転させることによりつまり前記水酸ィ匕物等の付着面を陽分極させ ることによりカルシウムイオン及びマグネシウムイオンとして被処理水中に再溶解させ て電極から除去しながら電解反応を進めることが可能である。反転の間隔と時間は、 両極の形状が同じであれば、格別の規定は不要である。  [0044] As one embodiment of the present invention, a conductive diamond electrode can also be used for the cathode. In addition, when 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. In other words, calcium hydroxide or magnesium ion hydroxide or the like adheres to the cathode surface of the electrolytic cell, so periodic scale removal is necessary. In order to prevent the adhesion of scales, there have been reported 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.). When these methods are used, 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.
[0045] 導電性ダイヤモンド電極における通電中の電圧降下は、ダイヤモンド層の抵抗率 及び厚さ、並びに基板の抵抗率及び厚さ、及び電極への接続における抵抗に依存 するので、基板の電導率及びダイヤモンド層や電源への接合状態は、電極ァセンブ リでの全体的な電圧降下に対しては無視できるように設計されて!、るのが好ま 、。  [0045] Since the voltage drop during energization in the conductive diamond electrode depends on the resistivity and thickness of the diamond layer, and the resistivity and thickness of the substrate, and the resistance at the connection to the electrode, The connection to the diamond layer and the power supply is designed to be negligible for the overall voltage drop across the electrode assembly!
[0046] 電解酸化の際の電流密度は、一般に lOmAZcm2の程度で、電極での電圧降下 は 10〜： LOOVの範囲であるので、電流値と抵抗値の二乗の積である電力消費は極 めて大きくなり、相当のエネルギーが抵抗加熱となって失われてしまう。 [0046] 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.
したがって、本発明に好ましい電極は、ダイヤモンド層が 1Μ Ω cm未満の抵抗率と なるように、ダイヤモンド層厚さは十分に薄く（5 m未満）、基板は十分に高い電導 率を有している。 Therefore, the preferred electrode for the present invention is that the diamond layer has a resistivity of less than 1 Ωcm. Thus, the diamond layer thickness is sufficiently thin (less than 5 m), and the substrate has a sufficiently high conductivity.
[0047] し力し、より好まし!/、電極は、 100 Ω cm未満の抵抗率、及び lOOmAZcm2の電流 密度で電圧降下は IV未満となる厚さのダイヤモンド層を有する電極である。このよう な電極であれば、適当な電流密度で、抵抗加熱力 生じる電力損を低い状態に留め られる。好ましい電極は、 0. 1 Ω cm未満の抵抗率を有し、電流密度 lAZcm2で、電 極での電圧降下が 0. IV未満となるような厚さを有する電極である。 [0047] The electrode is an electrode having a diamond layer with a resistivity of less than 100 Ωcm 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 Ωcm, a current density of lAZcm 2 and a thickness such that the voltage drop at the electrode is less than 0.1 IV.
[0048] 本発明にお 、ては、電解槽の構造は公知の各種の構成で用いることができる。す なわち、単一室セルであってもよぐ又は陽極と陰極が膜で仕切られた分割セルであ つてもよい。最も簡単な実施態様は、単一室セルである。単一室セルでは、陽極と陰 極を隔てるバリヤ一がなぐしたがって溶質は陽極と陰極間を移動するのに制限を受 けない。  [0048] In the present invention, 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.
[0049] 2室セルにぉ 、ては、イオン交換膜、ミクロろ過膜、半透膜、多孔性膜、などの通電 性隔膜を陽極と陰極の間に挿入し、この隔膜はあるタイプのイオン種のみを陽極液 力 陰極液へ又はその逆方向へ通過させることができる。膜の機能は、陽極液と陰 極液が混合することなく電気的中性を保持することである。また、適当な膜を用いれ ば、その膜を通過して移動するイオンの性質を制御することができる。  [0049] In the two-chamber cell, 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.
[0050] しかしながら、 2室セルにおいては、膜の耐久性が限られているので、ファゥリングを 生じな 、ように適切に交換するなどの管理が必要である。  [0050] However, in the two-chamber cell, since the durability of the membrane is limited, it is necessary to manage such as appropriately replacing so as not to cause fouling.
単一室セル及び 2室セルの使用については、簡易という立場からは、単一室セル の使用が好ましい。し力しながら、隔膜の適切な管理とプロセス管理が可能ならば、 2 室セルがより好まし 、形態である。  The use of single-chamber cells and two-chamber cells is preferable from the standpoint of simplicity. However, if proper control of the diaphragm and process control are possible, a two-chamber cell is preferred and the form.
[0051] 本発明における電解酸ィ匕は、バッチ方式、再循環方式、連続方式の 、ずれの方式 を用いても良ぐ廃液処理の規模や処理の程度に応じて、適宜最も都合がよい方式 を選択できる。  [0051] 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.
[0052] ダイヤモンド層電極を含有する電気化学セルは、陽極と陰極の直接接続、もしくは ショートさせるような通路を生じさせることなぐ電極間間隙をできるだけ小さく保つ。 数センチメートルを超える大き 、電極間距離は許容できる力 好ま 、電極間間隙は 、 0. lmm〜50mmの範囲内であり、最も好ましい状態は電極間間隙が 0. 5mm〜20 mmの範囲内にある。 [0052] 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.
[0053] 電解酸化は、電流密度が lmAZcm2〜10AZcm2、流速 Zセル体積比が 0. 001 〜1000s_1であり、電極表面積が顕微鏡により測定した幾何学的電極表面と等しい 力 又はそれより大きぐとくに幾何学的電極表面の 1〜5倍の表面積であることが好 ましい。しかしながら、電流密度が 20mA/cm2〜2A/cm2の範囲であり、流速/セ ル体積比が 0. 01〜50s_1であり、本発明の最良形態は、電流密度が 50mAZcm2〜 800mAZcm2であり、流速 Zセル体積比が l〜20s_1の範囲であり、電極表面積が、 顕微鏡で測定した幾何学的電極面積の少なくとも 2倍の場合がさらに好ましい。 好ましい通電量は被処理廃液の CODにも依存する力 通常写真廃液 1リットルに つき 0. 5MQ以上であり、好ましくは 1〜10MQであり、より好ましくは 2〜8MQである (MQはメガクーロン）。 [0053] electrolytic oxidation, 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. However, 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. , and 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) .
[0054] <生物処理 > [0054] <Biological treatment>
廃水のアンモニア性窒素にカ卩えて COD値も高い場合には、硝化脱窒処理の前処 理として好気性生物処理を組合わせて処理することも可能である。  If 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.
この種の廃水は、好ましくは生物処理に好適な COD値になるように水希釈が行な われる。水希釈は、通常 10〜50倍程度、好ましくは 10〜： L00倍程度の希釈が必要 であるが、過度の水希釈は硝化脱窒工程には不利であるので、硝化脱窒工程を組 合わせる本発明の態様としては、好気性生物処理と組合わせる方法も可能であるが 、物理ィ匕学的処理と組合わせる態様がより好ま 、。  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. As an aspect of the present invention, a method in combination with an aerobic biological treatment is possible, but an aspect in combination with physical physical treatment is more preferable.
[0055] 生物処理の形態 [0055] Form of biological treatment
生物処理の方法としては、汎用公知の好気性生物処理を適用できる。すなわち、 一般的な活性汚泥法のほか、ラグーン法、散水濾床法、回転円板法等、好気性微生 物を非処理液に含有させて曝気あるいは空気や酸素に接触させる方法であれば本 発明の生物処理に用いることができる。各事業所において廃液処理を行うには、廃 液流流入系と汚泥の分離 ·返送系と処理済み廃液排出系を備えた曝気槽力 なるコ ンパタトなバイオリアクターが好まし 、。これらの生物処理のより具体的方法につ!、て は「廃水処理プロセス、設計理論と実験法」 W. W.エッケンフェルダー、 D. L.フォ ード著、松井三郎訳技報堂出版および「生物学的水処理技術と装置」、化学工学協 会編、培風館に記載されている。 As a biological treatment method, a generally known aerobic biological treatment can be applied. In other words, in addition to the general activated sludge method, 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. In order to perform waste liquid treatment at each office, 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. For more specific methods of these biological treatments, please refer to “Wastewater treatment process, design theory and experimental method” WW Ekkenfelder, DL By Sado Matsui, translated by Saburo Matsui, published by Gihodo, and “Biological Water Treatment Technology and Equipment”, edited by the Chemical Engineering Society, and Baifukan.
好ましい好気性生物処理方法は、微生物を担体に担持 ·固定化させた形態で行う 処理方法である。固定化処理の中でも、包括処理が特に好ましい。  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. Among the immobilization processes, the comprehensive process is particularly preferable.
[0056] 微生物固定ィ匕担体の製造方法は、微生物の担持 ·固定ィ匕方法としては、担体から 生分解菌が流出しないように固定される方法ならばその種類、形式を問わないが、例 えば、微生物が付着して生物膜を形成するような担体を用いる付着生物膜法、担体 と培地を混合して微生物を培養する担持培養法、水不溶性の担体に微生物を結合 させる担体結合法、減圧下で担体の孔隙内に微生物を封入する方法、 2個以上の官 能基を持つ試薬によって菌体内に架橋を形成させて固定化する方法、微生物を高 分子のゲル内部や皮膜などに閉じ込める包括固定ィヒ法、さらに結合手段により共有 結合法、物理的吸着法、イオン結合法及び生化学的特異結合法などと分類される担 体結合法が知られている力 本発明には、これらの公知の方法を用いることができる 。中でも、付着生物膜法及び包括固定ィ匕法が好ましく，とりわけ包括固定ィ匕法が優 れている。  [0056] 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. For example, 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 ion binding method, a biochemical specific binding method, and the like, depending on the binding means. Use known methods Door can be. Of these, the attached biofilm method and the inclusive fixation method are preferred, and the inclusive fixation method is particularly excellent.
[0057] 付着微生物膜法の特徴は、微生物を高濃度化することができ、処理効率を向上さ せることができる。また、通常は系外に洗い出されてしまうような増殖速度が遅い菌を 系内に留めることができる。また、微生物が安定して棲息できる状態に保てることも特 徴としてあげられる。  [0057] 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.
実施例  Example
[0058] [種菌試料の採取'馴化]  [0058] [Inoculum Sample Collection 'Acclimation]
富士写真フィルム (株)足柄工場の終末処理場力 採取した活性汚泥を種菌とし、 以下に示す各種担体に担持した後、下記の HEPES緩衝液をベースにした培養液中 で培養する過程で、培養液中のアンモニア濃度を徐々に上げつつ、高濃度のアンモ ユアに適性のある硝化菌を馴化、育成した。  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.
[0059] 培着液組成: [0059] Culture solution composition:
^ 含有畺 八  ^ Contains 8
(NH ) SO 2500〜25000 HEPES 11900 (NH) SO 2500-25000 HEPES 11900
KH PO 500  KH PO 500
2 4  twenty four
NaHCO 500  NaHCO 500
3  Three
MgSO - 7H O 100  MgSO-7H O 100
4 2  4 2
CaCl -2H O 5  CaCl -2H O 5
2 2  twenty two
NH (Fe-EDTA)_ 1  NH (Fe-EDTA) _ 1
4  Four
培養中は適時 0.1N NaOHにて pH7.5に調整、維持した。  During culture, the pH was adjusted to 7.5 and maintained with 0.1N NaOH as appropriate.
[0060] 使用担体[0060] Carrier used
m _械分 無機分散体 メーカー _  m _Machinery Inorganic dispersion manufacturer _
クラゲール KU PVA クラレ  Kragale KU PVA Kuraray
BCP担体 BC PP、PE、PS、 活性炭 テ'、ンカェンシ'、ユアリンク'、 BCP carrier BC PP, PE, PS, activated carbon Te ', Nkaenshi', Your Link ',
PVAZホウ酸担体 PB PVA、ホウ酸 （今回調製） PVAZ boric acid carrier PB PVA, boric acid (Prepared this time)
PVAZホウ酸担体 A PBA PVA、ホウ酸、活性炭 （今回調製）  PVAZ boric acid carrier A PBA PVA, boric acid, activated carbon (Prepared this time)
PVAZホウ酸担体 B PBB PVA、ホウ酸、活性アルミナ (今回調製）  PVAZ boric acid carrier B PBB PVA, boric acid, activated alumina (Prepared this time)
PVA/ホウ酸担体 c PBC PVA、ホウ酸、焼却飛灰 _ (^mmm) _  PVA / boric acid carrier c PBC PVA, boric acid, incineration fly ash _ (^ mmm) _
[0061] [菌体の担持]  [0061] [Supporting bacterial cells]
物理的吸着による担持 (比較例）  Support by physical adsorption (comparative example)
3Lの丸底フラスコに 1Lの上記培養液（(NH ) SO濃度 2500mgZUを入れ、液中  Place 1 L of the above culture solution ((NH 4) SO concentration 2500 mgZU in a 3 L round bottom flask.
4 2 4  4 2 4
に設置した曝気用ボールフィルターに送気しながら KU又は BCを lOOmL投入した。 工場の終末処理場力も採取した活性汚泥 100mlを静置し、沈降したフロックを反応 容器である上記フラスコに投入し、 3日間曝気を続け、微生物を吸着させた。担体を 取出し、馴化培養に供した。  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.
[0062] 包括固定による担持 (本発明例） [0062] Support by inclusive fixing (Example of the present invention)
18%PVA (クラレ PVA-HC)水溶液に上記活性汚泥を重量比 1： 1で混合し、先端を 絞ったガラス管を通して、飽和ホウ酸水溶液中に球状に滴下した。瞬時に形成され たゲルビーズは 24時間緩やかに攪拌し、完全にゲル化した。ビーズはその後純水中 で 3日間脱ホウ酸して、馴化培養に供した。なお、 PVAZホウ酸担体 A〜Cは活性炭 と活性アルミナ (和光純薬製)、焼却飛灰 (足柄工場自家発電燃焼炉より採取)をそ れぞれ 18%PVA水溶液に 5体積％添加して上記同様にゲルィ匕調製した。 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.
[0063] [馴化培養] [0063] [conditioned culture]
それぞれの 3Lの丸底フラスコに 1Lの上記培養液 ((NH ) SO濃度 2500mgZL)を  Into each 3L round bottom flask, add 1L of the above culture solution ((NH) SO concentration 2500mgZL).
4 2 4  4 2 4
入れ、液中に設置した曝気用ボールフィルターに送気しながら菌体を担持した各種 担体を 5体積％ずつ投入、曝気により攪拌しながらアンモニア濃度を毎日測定し、ァ ンモニァ濃度が半減した時点で回分式に硫酸アンモニゥムを添加し、徐々に負荷を 高めた。この間 pHは約 7. 5に保った。 25000mgZL濃度における硝化が進行するま でに馴化するのに要した期間を表 1に示す。  5% by volume of various carriers carrying the cells while feeding to an aeration ball filter installed in the liquid, and measuring the ammonia concentration every day while stirring by aeration. When the ammonia concentration is halved Ammonium sulfate was added batchwise to gradually increase the load. During this time, the pH was maintained at about 7.5. Table 1 shows the time required to acclimatize until nitrification proceeds at a concentration of 25000 mgZL.
更に、馴化後の担体を用いた同時処理実験で、 25000mgZLの硫酸アンモ-ゥム が lOOOmgZLまで低減されるのに要した時間を表 2に示した。  Furthermore, Table 2 shows the time required to reduce 25000 mgZL of ammonium sulfate to lOOOmgZL in a simultaneous treatment experiment using the conditioned medium.
なお、硝酸、亜硝酸及びアンモニアの定量分析はイオンクロマトグラフィーにて行つ た。  Quantitative analysis of nitric acid, nitrous acid and ammonia was performed by ion chromatography.
[0064] [表 1]  [0064] [Table 1]
Figure imgf000020_0001
Figure imgf000020_0001
[0065] [表 2] [0065] [Table 2]
No. 使用担体 lOOOmgZLまでの処理に要した期間 備考No. Used carrier Period required for processing up to lOOOOmgZL Remarks
1 KU 25曰 比較例1 KU 25 曰 Comparative example
2 BC 23 曰 比較例2 BC 23 曰 Comparative example
3 PB 28 曰 比較例3 PB 28 曰 Comparative example
4 PBA 10 曰 本発明4 PBA 10 曰 The present invention
5 PBB 15 曰 本発明5 PBB 15 曰 The present invention
6 PBC 12 曰 本発明 [0066] 本発明例の無機分散体を介在させた包括固定化体分散物試料 (No. 4〜6)は、 高アンモニア性窒素量に速やかに順応し、かつ lOOOmgZLまでアンモニア性窒素 を分解させるのに要する時間も顕著に短縮される。 6 PBC 12 曰 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.
[実施例 1]  [Example 1]
[0067] アンモニア含有量が高 、ことで知られて 、るコ一クス炉工場廃水の処理への応用 を試みるために、該廃水のモデル液を調製した。即ち、フエノール 1. 5g/ クレゾ ール 1. 5/ チォ硫酸アンモ-ゥム lgZL及び硫酸アンモ-ゥム 13gZLの溶液を 調製した。この溶液の CODは 11000mgZL、アンモニアは 3400 mgZLであった。こ れを以下に記す電解酸ィ匕処理を施した後、実施例 1で用いた馴化済みの担持硝化 菌による処理を行なった。  [0067] 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.
電解に関しては、陽極に二酸ィ匕鉛（日本カーリット社製、 LD400)、陰極にステンレ ス（SUS-316)を用い、陰極 3枚と陽極 2枚を並列で交互に取り付けた容量 3Lのタンク に、廃液 2Lを入れて電解した。それぞれの電極面積は、 200cm2であり、極間距離 は 25mm、廃液はスターラーで撹拌しながら、電流を 10Aとして、 20時間電解酸化処 理を行った。この電解酸ィ匕試料を Aとする。 For electrolysis, a 3L tank with 3 cathodes and 2 anodes attached in parallel, using nickel oxide lead (LD400 manufactured by Nippon Carlit Co., Ltd.) as anode and stainless steel (SUS-316) as cathode. Then, 2 L of waste liquid was added and electrolyzed. The area of each electrode was 200 cm 2 , the distance between the electrodes was 25 mm, and the waste liquid was subjected to electrolytic oxidation treatment for 20 hours at a current of 10 A while stirring with a stirrer. Let this electrolytic acid sample be A.
[0068] 陽極を、同一面積の、白金電極、及びダイヤモンド電極にそれぞれ変えた以外は 同じ条件で実験を行った。これらの電解酸化試料をそれぞれ B及び Cとする。 なお 、使用したダイヤモンド電極は、ホウ素ドーピングイ匕ダイヤモンド層電極で、（100)単 結晶シリコンゥエーハ（0.76mm厚さ）上に蒸着したダイヤモンド層にホウ素を含ませた ホウ素ドーピングィ匕多結晶質ダイヤモンド層（約 2. 5 μ m厚さ）であり、米国の Advanc ed Technology Materials, Inc., 7 Commerce Drive, Daubury, CT 06810より巿販され ているものを用いた。このダイヤモンド層の抵抗率は 80m Ω cmであり、ドープしたホウ 素濃度は、 5000mg/kgであった。また、シリコンゥエーハの抵抗率は 15m Ω cmであつ た。銅電線をシリコン基板へ、市販の銀エポキシ榭脂（Epo-Tek H20E, Epoxy Techn ology In ）を用いて固定してあり、溶液の、電極の裏側へのリークを、 RTVシリコーン を用いて最少にしてあり、ダイヤモンド電極の裏面同士を張り合わせ臨界面を密封し てある。また、白金電極は、市販の白金被覆電極板をそのまま用いた。  [0068] An experiment was performed under the same conditions except that the anode was changed to a platinum electrode and a diamond electrode having the same area. Let these electrolytic oxidation samples be B and C, respectively. 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 μm 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 mΩcm, and the doped boron concentration was 5000 mg / kg. The resistivity of silicon wafer was 15mΩcm. 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.
各電極対間の印加電圧は、陰極に対して二酸ィ匕鉛陽極が 3.5V、白金陽極が 5V、 ダイヤモンド陽極力 Vであった。 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.
電解後の反応液を、粒状水酸ィ匕カリウムで pH6. 5に中和し、ろ過を行ない、沈澱 した固形分を除去した。各液の COD、アンモニア濃度を表 3に示す。  The 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.
[表 3]  [Table 3]
Figure imgf000022_0001
Figure imgf000022_0001
[0070] この試料溶液を実施例 1に記載した装置及び馴化済みの担持硝化菌を用いて同 様に処理し、 5日後のアンモニア濃度を測定した。なお、処理中の容器内の PHにつ いては、 pHコントローラー (東京理ィ匕製)を設け、硫酸または水酸化ナトリウムの添加 により 7. 5 ±0. 1に保った。結果を表 4にまとめて示す。 [0070] This sample solution was treated in the same manner using the apparatus described in Example 1 and the conditioned nitrifying bacteria, and the ammonia concentration after 5 days was measured. Incidentally, P H information about the container being processed, the pH controller (Tokyo Ryi匕製) provided, maintained at 7. 5 ± 0. 1 by the addition of sulfuric acid or sodium hydroxide. The results are summarized in Table 4.
[0071] [表 4]  [0071] [Table 4]
No. 料 処理 アンモニア mg/L 備考 No. Material Treatment Ammonia mg / L Remarks
液  Liquid
1 A KU 2 8 0 0 比較例  1 A KU 2 8 0 0 Comparative example
2 A BC 2 7 7 0 比較例  2 A BC 2 7 7 0 Comparative example
3 A PB 2 8 7 0 比較例  3 A PB 2 8 7 0 Comparative example
4 A PBA 3 0 0 本発明  4 A PBA 3 0 0 The present invention
5 A PBB 3 2 0 本発明  5 A PBB 3 2 0 The present invention
6 A PBC 3 1 0 本発明  6 A PBC 3 1 0 The present invention
7 B KU 2 9 1 0 比較例  7 B KU 2 9 1 0 Comparative example
8 B BC 2 8 6 0 比較例  8 B BC 2 8 6 0 Comparative example
9 B PB 3 0 5 0 比較例  9 B PB 3 0 5 0 Comparative example
10 B PBA 3 4 0 本発明  10 B PBA 3 4 0 The present invention
11 B PBB 3 7 0 本発明  11 B PBB 3 7 0 The present invention
12 B PBC 3 5 0 本発明  12 B PBC 3 5 0 The present invention
13 C KU 1 8 2 0 比較例  13 C KU 1 8 2 0 Comparative example
14 C BC 1 7 6 0 比較例  14 C BC 1 7 6 0 Comparative example
15 C PB 1 8 4 0 比較例  15 C PB 1 8 4 0 Comparative example
16 C PBA 2 3 0 本発明  16 C PBA 2 3 0 The present invention
17 C PBB 2 9 0 本発明  17 C PBB 2 9 0 The present invention
18 C PBC 2 6 0 本発明 表 3力ら!、ずれの電解酸化処理でも原液の COD値 6000mgZLの 50%以上が電 解酸ィ匕除去されることが判るが、ダイヤモンド電極を陽極に用いた場合 (試料 C)の場 合は、残存 CODが 95mgZLという顕著な COD低減効果が示された。表 4では、ァ ンモユア性窒素分解菌を包括固定ィ匕して試験した本発明例 (No. 4〜6、 10〜12、 15〜18は、優れた硝化脱窒効果を示したが、比較例では、硝化脱窒効果は乏しか つた。本発明例の中でも電解酸ィ匕過程をダイヤモンド電極を用いた試料 15〜18は、 アンモニア性窒素及び CODのいずれにも優れた低減効果があることが示された。 18 C PBC 2 6 0 The present invention 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. However, when 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. In the examples, the nitrification denitrification effect was poor, and among the examples of the present invention, Samples 15 to 18 using a diamond electrode in the electrolytic oxidation process had excellent reduction effects on both ammoniacal nitrogen and COD. It has been shown.

Claims

請求の範囲 The scope of the claims
[1] 化学的酸素要求量 (COD)が 0. 3gZL以上でかつアンモニア性窒素量が 0. 5g/ L以上である、写真処理廃水以外の廃水を、物理ィ匕学的に又は生物学的に処理し たのちアンモニア酸ィ匕細菌と無機物分散体とを含有する包括固定体により処理する ことを特徴とする廃水処理方法。  [1] Wastewater other than photographic processing wastewater with a chemical oxygen demand (COD) of 0.3 gZL or more and an ammoniacal nitrogen content of 0.5 g / L or more is physically or biologically A wastewater treatment method characterized by treating with a entrapping immobilization body containing ammonia acid bacteria and an inorganic dispersion.
[2] 物理化学的処理が導電性ダイヤモンド電極を陽極として用いる電解酸化処理であ ることを特徴とする請求項 1に記載の廃水処理方法。  [2] The wastewater treatment method according to [1], wherein the physicochemical treatment is an electrolytic oxidation treatment using a conductive diamond electrode as an anode.
[3] 無機物分散体が炭素、酸ィ匕アルミニウム、酸ィ匕ケィ素から選択される少なくとも 1種 を主成分とする無機物分散体であることを特徴とする請求項 1又は 2に記載の廃水処 理方法。  [3] The wastewater according to claim 1 or 2, wherein the inorganic dispersion is an inorganic dispersion mainly composed of at least one selected from carbon, acid-aluminum, and acid-caine. Processing method.
[4] アンモニア酸ィ匕細菌の包括固定体が該細菌をポリビュルアルコール (PVA)を主体 としたゲルに包括した包括固定体であることを特徴とする請求項 1〜3のいずれかに 記載の廃水処理方法。  [4] The entrapping immobilization body of the ammonia acid bacterium is an entrapping immobilization body in which the bacterium is encapsulated in a gel mainly composed of polybulal alcohol (PVA). Wastewater treatment method.
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