JP2007260664A - Method for treating organic waste water, membrane separation activated sludge treatment apparatus for treating organic waste water, and method for producing filter-feed animalcule agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus capable of stably and continuously treating waste water for a long time by preventing or remarkably reducing a trouble of membrane permeability, foaming, scum development, increase in viscosity, and the like which tend to appear in the membrane separation activated sludge treatment of organic waste water. <P>SOLUTION: The membrane separation activated sludge method treats with activated sludge the organic waste water containing an organic component in a biological reactor 1 and discharges purified water via a membrane-filtering treatment through an immersed membrane separation device 2 disposed in the biological reactor. The method enhances the operation of a filter-feed animalcule group excellent in preying on dispersible bacteria causing the trouble by performing a filter-feed operation enhancing means capable of increasing the amount of the filter-feed animalcule group in the activated sludge water in the biological reactor. The filter-feed animalcule group is acclimated in advance with the bacteria causing the trouble as a prey and is charged into the process enhancing the operation to operate in the environment suitable for their growth to remove the bacteria causing the trouble. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for treating organic wastewater that can be suitably used for treating organic wastewater by the membrane separation activated sludge method, such as industrial wastewater containing polysaccharides discharged from food factories and the like and domestic wastewater. The present invention relates to a processing apparatus.

  In the membrane separation activated sludge method applied to the treatment of organic wastewater, various phenomena that impair the treatment stability are known. For example, membrane permeability failure due to clogging of the membrane, severe foaming, scum generation, deterioration of aeration efficiency due to increase in viscosity, sludge fluidity reduction, defects due to bubble inclusion, and the like can be mentioned.

  On the other hand, in biological treatment of organic wastewater such as the activated sludge method, various methods for predicting and grasping instability have been proposed. For example, dissolved oxygen, redox potential, pH fluctuation, etc. are monitored. The method is known. Particularly in recent years, a technique for monitoring the growth of useful microorganisms and helping to control the growth has been proposed (Patent Document 1). Similarly, a technique for monitoring the growth of trouble-causing microorganisms has also been proposed. For example, filamentous bacteria (“Eikel boom type”), which is one of the causes of poor sedimentation phenomenon (filamentous bulking) in the activated sludge process. A method of monitoring 021N (Eikeboom Type 021N) bacteria, etc.) has been proposed (Patent Document 2).

  However, these conventional methods are not applicable to all biological treatment methods of organic wastewater, and are often not suitable particularly in the membrane separation activated sludge method. This is because, in general, the activated sludge method including the method described in Patent Document 2 is a treatment method. Therefore, it is important to focus on countermeasures against sedimentation defects such as reduced specific gravity and reduced compactness of sludge. This is because, unlike the activated sludge method, other factors such as poor membrane water permeability, foaming, scum generation, and increased viscosity become major problems in the membrane separation activated sludge method. Nevertheless, the instability prediction and grasping method and its control method appropriate for the membrane separation activated sludge method have not been sufficiently established.

  Moreover, in biological treatment of organic wastewater including the conventional activated sludge method, the effect of micro animals is described for the purpose of sludge volume reduction and improvement of treated water quality. For example, a method has been proposed in which a porous animal is introduced and a microanimal for treating excess sludge is grown (Patent Document 3). In this case, an object is to suppress the generation of excess sludge by feeding the excess sludge to the minute animals growing on the porous granules. In addition, a method has been proposed in which sludge is eaten by micro-animals that grow on the contact material in a multi-stage tank structure and suppress the generation of excess sludge (Patent Document 4). In addition, a method (Patent Document 5) that suppresses the generation of excess sludge by precipitating part of the returned sludge to aquatic earthworms has been proposed.

  All of these methods are aimed at suppressing the generation of excess sludge by precipitating sludge in general to micro animals, but the micro animals used here are efficient for sludge composed of bacteria and the like. As long as they prey well, any minute animal can be used.Sludge is usually composed of flocs that are floating bodies in which microorganisms are aggregated. Therefore, microanimals that prey mainly on aggregates such as flocs are suitable. It is used. For example, in addition to oil worms, nematodes, and caterpillars, there are some rotifers that prey on flocks. However, these micro-animal utilization methods are intended to suppress the generation of surplus sludge and improve the quality of treated water in consideration of conventional organic wastewater treatment methods such as the normal activated sludge method. In the membrane separation activated sludge method that operates at a sludge load of less than 0.15 kg-BOD / kg-VSS / day, the biggest problem is membrane permeability failure due to membrane clogging, severe foaming, generation of scum, However, it is not possible to obtain sufficient effects on the deterioration of aeration efficiency and sludge fluidity reduction with increasing viscosity.

  On the other hand, in the membrane separation activated sludge method, an operation method for performing the treatment while monitoring the state of the bacteria of the Flectobacillus family, and an operation method for performing the treatment while monitoring the prokaryotic organisms dispersed and present in the sludge mixed solution. Have been proposed (Patent Documents 6 and 7). If these methods are used, it is possible to predict and detect the occurrence of troubles, so it is possible to take prompt action, but the prediction and detection of troubles cannot always be fully utilized with the countermeasures listed here. There is a case.

JP 2001-128678 A JP 2002-119300 A Japanese Patent Laid-Open No. 11-10198 JP 2005-66595 A JP 2004-141802 A JP 2004-306026 A Japanese Patent Laid-Open No. 2005-40787

  The present invention has been made in response to the above-mentioned problems in the prior art, and its purpose is to prevent poor membrane permeability, foaming, and scum that are likely to occur when organic wastewater is treated by the membrane separation activated sludge method. It is to prevent or greatly reduce troubles such as generation and viscosity increase, and to stably carry out wastewater treatment for a long period of time.

In order to solve the above problems, the present invention has the following configuration. That is,
(1) Organic wastewater containing organic components is supplied to the biological reaction tank, the organic wastewater is treated with activated sludge in the biological reaction tank, and membrane filtration is performed by a submerged membrane separator installed in the biological reaction tank. In the membrane-separated activated sludge treatment method for removing the purified water, a filtration feeding enhancement means capable of increasing the amount of filtered feeding microanimals contained in the activated sludge liquid in the biological reaction tank is intermittently provided. Or the organic wastewater treatment method characterized by performing constantly.
(2) The organic wastewater treatment according to the above (1), wherein the filter-feeding microanimal group is a microanimal group having high predatory ability for prokaryotes that are dispersed and grown in the activated sludge liquid in the biological reaction tank. Method.
(3) The organic wastewater treatment method according to (2) above, wherein the prokaryotes that are dispersed and grown in the activated sludge liquid are CFB group bacteria that are dispersed and grown in the activated sludge liquid.
(4) High predation for at least one of the filter-feeding microanimal group bacteria of the Flectobacillus lineage bacteria, the Pedobacter lineage group bacteria, and the Flexibacter sancti lineage bacteria The organic wastewater treatment method according to the above (1), which is a group of minute animals having ability.

(5) Said (1)-(4) which measures the viscosity and / or filtration parameter | index of the activated sludge liquid in a biological reaction tank intermittently or always, and performs a filter feeding effect enhancement means according to this measurement result The organic wastewater treatment method according to any one of the above.
(6) Fractobacillus family bacteria, Pedobacter family bacteria, Flexibacterium sacti family bacteria, and activated sludge contained in the activated sludge liquid in the biological reaction tank The above (1) to (4) wherein at least one state of prokaryotes that grow in a dispersed state is intermittently or constantly measured, and the filtering feeding effect enhancing means is executed according to the measurement result The organic wastewater treatment method according to any one of the above.
(7) The filtering and feeding action enhancing means adds a substance containing the filtering and feeding microanimal group as a main component into the biological reaction tank, and / or a carrier and contact material for the filtering and feeding microanimal group. The organic wastewater treatment method according to any one of (1) to (6), which is to be installed in a biological reaction tank.
(8) The organic wastewater treatment method according to any one of (1) to (7), wherein the filter-feeding microanimal group is a filter-feeding microanimal group including metazoans.
(9) The organic wastewater treatment method according to (8) above, wherein the metazoan is a stag beetle.
(10) The organic wastewater treatment method according to any one of (1) to (9), wherein the BOD sludge load in the biological reaction tank is less than 0.15 kg-BOD / kg-VSS / day.

(11) A biological reaction tank for storing organic wastewater and treating activated sludge, and a submerged membrane separation membrane installed in the biological reaction tank for solid-liquid separation treatment of the activated sludge liquid A membrane separation activated sludge treatment apparatus, comprising a filtration feeding microanimal group addition means for adding a filter feeding microanimal group into a biological reaction tank and / or a side reaction tank for filtration feeding microanimal; and / or Alternatively, a membrane-separated activated sludge treatment apparatus for organic wastewater, characterized in that a carrier or contact material for a filter-feeding microanimal is installed in a biological reaction tank.
(12) A means for intermittently or constantly measuring the viscosity and / or filtration index of the activated sludge liquid in the biological reaction tank is provided, and based on the level of the measured viscosity and / or filtration index, The membrane separation activated sludge treatment apparatus for organic wastewater according to the above (11), comprising means for judging the feasibility of the edible microanimal group addition means.
(13) Fractobacillus family bacteria, Pedobacter family bacteria, Flexibacterium sacti family bacteria, and activated sludge contained in the activated sludge liquid in the biological reaction tank Provided with means for intermittently or constantly measuring the state of at least one of the prokaryotes growing dispersed therein, and based on the measured viscosity and / or level of filtration index The membrane separation activated sludge treatment apparatus for organic wastewater according to the above (11), comprising means for judging the feasibility of the minute animal group addition means.
(14) A micro-animal-containing solution containing a filter-feeding microanimal group collected from an activated sludge solution, or a filter-feeding microanimal group isolated from an activated sludge solution is converted into a Flectobacillus strain group bacteria, By feeding on at least one of the Pedobacter family bacteria, the Flexibacter sancti family bacteria, and the prokaryotes that grow dispersed in activated sludge, the filter-feeding microbes A method for producing a filter-feeding microanimal preparation characterized by producing an additive containing a large amount of animals.

  According to the present invention, when treating organic wastewater by the membrane-separated activated sludge method, the action of the filter-feeding microanimal group is strengthened. Therefore, prokaryotes and CFB group bacteria present in a dispersed state in the sludge mixed solution. In addition, it is possible to suppress or prevent troubles related to the bacteria belonging to the family Flectobacillus, Pedobacter, and Flexibacter sancti. This is because problems such as poor membrane permeability, foaming, scum, and increased viscosity, which are problems when treating organic wastewater by membrane separation activated sludge method, are dispersed in the sludge of membrane separation activated sludge method. This is caused by the emergence of these bacteria, so that the presence of the filter-feeding micro-animals can be preferentially removed by the presence of dispersed bacteria that cause the above problems. is there.

  By preferentially enhancing the action of these filter-feeding microanimal groups, it is possible to more efficiently solve the problems of the membrane-separated activated sludge method than simply strengthening the general action of microanimals. It was. Further, in enhancing the action of the filter-feeding microanimal group, the effect of the present invention can be obtained more efficiently and reliably by using the filter-feeding microanimal group having excellent predatory ability against the above-mentioned trouble-causing microorganisms. It became possible. In addition, the filter-feeding micro-animal group is obtained by previously acclimatizing this specific cause-causing microorganism as a feed, and when it is strengthened, it is added to these and then allowed to act in its preferred growth environment. Trouble-causing microorganisms can be removed.

  Hereinafter, the present invention will be described in detail and specifically.

  In the present invention, the membrane separation activated sludge method refers to a method that uses membrane separation to obtain a clear treatment liquid by removing organic substances in waste water and pollutants such as nitrogen and phosphorus by microorganisms such as activated sludge. . The membrane separation method is not particularly limited, such as an immersion membrane method, an external membrane separation method, and a rotating flat membrane method.

  Further, in the present invention, the microanimal is a protozoan such as a flagellate, a ciliate or a fleshworm, or a micrometazoan including a bag-shaped animal or an annelid, and refers to a eukaryote having a body length of 5 mm or less. The micro animal group refers to a mixed system of micro animals composed of one or more kinds of micro animals. A filter-feeding micro-animal is a water flow around the mouth mainly caused by the movement of cilia adhering to the vicinity of the mouth. When animals are given floc and dispersal bacteria, they refer to small animals that eat more dispersal bacteria than flocs. In addition, when taking a non-filter feeding type feeding method, it is different from this, and it eats so that it eats up eating subjects, such as a flock. Such a feeding system is referred to as aggregate feeding in the present invention. Metazoa refers to multicellular eukaryotes.

  Here, “existing in the sludge mixed solution” means not existing in the floc. A floc is an aggregate in which a plurality of microorganisms in activated sludge are bonded to each other via an extracellular polymer, etc., and the major axis exceeds 10 μm (however, filamentous bacteria are not included when defining the diameter) Point to something. Bacteria that are dispersed in the sludge mixture include, for example, bacteria that are free and growing alone, bacteria that are linked to several bacteria (diococci and streptococci), and floc. Not contained filamentous bacteria, and can be confirmed by optical microscope observation.

  In addition, in the present invention, the bacterium belonging to the family Flectobacillus is a 16S ribosomal RNA gene that is often used as a phylogenetic phylogenetic index and has a homology of 88% or more with respect to the base sequence described in SEQ ID NO: 1. It refers to bacteria, regardless of whether it can be cultured. Bacteria included in the bacteria of the family Flectobacillus include, for example, bacteria belonging to the genus Flectobacillus, such as Flectobacillus major, Flectobacillus spruncae, and Flectobacillus sp. EP293, Flectobacillus sp. str. MWH38 etc. are mentioned. Naturally, even if the bacteria are not named or classified, or are not phylogenetic and are given an inappropriate genus name, if they meet the above-mentioned conditions, they will be affected by the relatedness. A phylogenetic bacterium.

  In addition, the Pedobacter family group bacteria have a homologous ratio of 88% or more in the corresponding part of the 16S ribosomal RNA gene which is often used as a phylogenetic phylogenetic index with respect to the base sequence described in SEQ ID NO: 2. It refers to bacteria, regardless of whether it can be cultured. Bacteria contained in the Pedobacter family bacteria include Pedobacter bacteria and Sphingobacteria bacteria. Specifically, “Bergey's Manual of Systematic Bacteriology” using a bacterial taxon defined in molecular phylogeny (George M.). Garrity et al., 2nd edition, Springer-Verlag, 2002, p. 119-166), the sphingobacteria of the class Sphingobacteria of the phylum Bacteroidetes. (Order Sphingobacterias) Family sphingobacteria They include bacteria that are classified as iaceae).

  Specific bacterial species include, for example, Pedobacter africanus, Sphingobacterium sp., SAFR-022, Pedobacter sp. EC2 (Bacteroidetes bacteria EC2), Flavobacterium sp. MTN11 (Flavobacterium sp. MTN11), Cytophagales strain MBIC4147 (Cytophagales str. SPICES PC1.9 (Spin obiumium like sp.PC1.9), Glacier bacteria FJS5 (glacier bacteria FJS5), Pedobacter sultans (saltans), Flavobacterium mitsutii (mizutaii), sphingobacterium faecium (faecium), faecium (faecium) Examples thereof include spiritivorum, sphingobacterium multivolum, and sphingobacterium sarpophyllum.

  Naturally, even if bacteria that have not been named or classified, or that have not been phylogenically classified and given an inappropriate genus name, if they meet the above conditions, the Pedobacter strain is Group bacteria. In monitoring, from the viewpoint of high frequency of appearance at the time of trouble, simplicity, and accuracy, the corresponding part of the 16S ribosomal RNA gene has a homology of 93% or more with respect to the base sequence described in SEQ ID NO: 2. It is also possible to focus on bacteria. Specifically, in “Burge's Manual of Systematic Bacteriology”, a considerable amount of bacteria are included as belonging to the genus Pedobacter.

  On the other hand, in the present invention, the bacterium belonging to the family of Flexibacterium sacti refers to a bacterium in which the corresponding part of the 16S ribosomal RNA gene has a homology of 85% or more with respect to the base sequence described in SEQ ID NO: 3. Regardless of whether or not. Bacteria contained in the Flexibacter sancti family bacteria include, for example, Flavobacterium ferruginum, Cytoferga avensicola, Flexibacter filiformis, Kitinofarga pinensis (Chitinophaga pinensis), Flexibacter sancti and the like. The names and classifications of the flexibacter sancti strains are often confused, and it is not possible to list typical genus names. However, if the above conditions are met, the relatedness of flexibacter sancti Sancti strain bacteria.

  And, the state of the Flectobacillus strain bacteria and / or the Pedobacter strain group bacteria and / or the Flexibacter sancti strain group bacteria is the number of the Flectobacillus strain bacteria, the Pedobacter strain bacteria, and the Flexibacter sancti strain bacteria. And concentration, dominance, and characteristics.

  In the present invention, the CFB group bacterium is a bacterial taxonomic group defined by molecular phylogenetic taxonomy, and refers to a bacterial group classified into the phylum Bacteroides. The classification of bacteria is described in “Bergey's Manual of Systematic Bacteriology” (edited by George M. Garrity et al., 2nd edition, Springer Fairerk (Springer). Verlag), 2002, p.119-166), and various phylogenetic classification services can be used.

  In the present invention, organic wastewater is treated by, for example, the treatment apparatus shown in FIG. 1, and the finally obtained clarified liquid is decomposed to such an extent that the organic matter can be discharged into a river or the like as it is. The organic wastewater treated here includes industrial wastewater and domestic wastewater. In the present invention, there is a high frequency of troubles involving prokaryotes, CFB group bacteria, Flectobacillus group bacteria, Pedobacter group bacteria, and Flexibacter sancti group bacteria present in the sludge mixture. Can be more suitably used for organic wastewater containing a sugar component as a main component. This is presumed to be due to abnormal growth of the above bacterial group that seems to have a relatively high availability for sugar. Examples include industrial wastewater discharged from food factories and the like.

Here, sugar as a main component refers to organic wastewater in which the amount of organic carbon in the sugar is 50% or more of the total amount of organic carbon in the organic wastewater. The existence form does not matter whether it is a dissolved state or a suspended state. The amount of organic carbon in the sugar is an amount calculated from the sugar concentration value measured by, for example, the phenol sulfate method or the anthrone sulfate method, assuming that the composition formula of the sugar is CH ₂ O. Similarly, the present invention can be suitably employed when the BOD sludge load is less than 0.15 kg-BOD / kg-VSS / day in terms of the high frequency of trouble occurrence. BOD sludge load is an index that expresses the amount of pollutant load introduced per day per unit sludge mass in the system in terms of biochemical oxygen demand (BOD). The operating characteristics of the entire wastewater treatment system To express. On the other hand, even when the water temperature is low or when the load fluctuation is severe, the present invention can be suitably employed in that the frequency of occurrence of the trouble is high.

  The processing apparatus shown in FIG. 1 includes a biological reaction tank 1 containing sludge containing microorganisms, a raw solution pump 4 for supplying a raw solution to the biological reaction tank 1, and a membrane separation for solid-liquid separation of the biologically processed processing liquid. The apparatus 2, the suction pump 3 that sucks the separation liquid during solid-liquid separation, and the prokaryote, CFB group bacteria, Flectobacillus strain group bacteria and pedobacter dispersed in the sludge mixed liquid in the biological reaction tank 1 And monitoring means 7 for monitoring the status of the strain group bacteria, the Flexibacter sancti strain group bacteria. The membrane separation device 2 is immersed in a treatment liquid in the biological reaction tank 1, and oxygen is supplied below the membrane separation device 2 to advance the aerobic treatment and to clean the membrane surface. An aeration device 5 connected to is provided. In addition, a sludge extraction pump 13 for extracting excess sludge as necessary is installed below the biological reaction tank 1.

Here, prokaryotes, CFB group bacteria, Flectobacillus group bacteria, Pedobacter group bacteria, Flexibacter sancti group bacteria (collectively referred to as trouble-related microorganisms) present dispersed in the sludge mixed solution. From the viewpoint of increasing the frequency of occurrence of troubles involving slag, the present invention can be suitably employed when the sludge residence time is operated for 40 days or more, and more suitably for 300 days or more. Similarly, the BOD volumetric load can be preferably used at 0.5 kg-BOD / m ³ / day or more, and more preferably 1.0 kg-BOD / m ³ / day or more. . Although the principle is not clear, prokaryotic organisms, CFB group bacteria, and Flectobacillus strains that are dispersed in the sludge mixture according to the increased sludge residence time and BOD volumetric load. This may be because it is advantageous for the growth of group bacteria, Pedobacter group bacteria, and Flexibacter sancti group bacteria, and the microbiota may change.

  The biological reaction tank 1 contains sludge containing microorganisms, and these microorganisms act as organic matter-degrading bacteria and further decompose these microorganisms to perform biological treatment. Microorganisms contained in sludge contribute to the decomposition of organic substances such as bacteria, yeasts and fungi including fungi, and are obtained from the natural world by accumulation culture and acclimatization, such as soil, compost, and sludge. It is also possible to isolate and use the main microbial group involved in the degradation from this conditioned solution.

  The biological reaction tank 1 must contain other components necessary for the growth of microorganisms. Therefore, for example, nitrogen, phosphorus, potassium, sodium, magnesium and other metal salts are added to the bioreactor, except when already contained in the stock solution.

  As the membrane separation device 2 provided in the biological reaction tank 1, a module formed using a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane, a reverse osmosis membrane, or the like can be used. From the economical point of view, a module using a microfiltration membrane or an ultrafiltration membrane that has a high filtration rate and can be made compact and is easy to maintain is preferable. The membrane may be a flat membrane, a hollow fiber membrane or the like. The form of the module is not particularly limited, but in this embodiment, an immersion type membrane module is used for space saving. In the case of the immersion type, the shape is preferably such that the fouling substance can be successfully removed by combination and arrangement with an aeration apparatus or a stirring apparatus. Furthermore, as a filtration method in the membrane separation device 2, there are a cross flow method and a total amount filtration method. If the cross flow method is employed, filtration can be performed while removing the membrane surface.

<Monitoring method for specific strains of bacteria>
Next, a method for monitoring the Bacterobacteria group bacteria, Pedobacter group bacteria, and Flexibacter sancti group bacteria will be described.
As the monitoring means / operation control device 7 for monitoring the state of the Fructobacillus group bacteria, Pedobacter group bacteria, Flexibacter sancti group bacteria in the sludge mixed liquid in the biological reaction tank 1, Based on the genetic information, RNA transcription characteristics, protein translation characteristics, expressed protein product characteristics, etc. of Pedobacter group bacteria, Flexibacter sancti group bacteria What monitors the state of a group bacteria can be used. Each of these methods will be described in detail below, but it is easy to monitor the status of the bacteria of the Fectobacillus group, Pedobacter group, and Flexibacter sancti group based on genetic information. To preferred.

  Specifically, when monitoring based on genetic information, a fluorescence measurement device such as a fluorescence microscope or a fluorescence image scanner, a nucleic acid hybridization detection device, a flow cytometer, a thermal cycler, and an electrophoresis device may be used. . In addition, when monitoring based on gene expression characteristics such as RNA transcription characteristics, protein translation characteristics and expressed protein product characteristics, fluorescence microscope, flow cytometer, electrophoresis apparatus, mass spectrometer, image analyzer, spectrophotometer A meter, a fluorescence measurement device, a light emission amount measurement device, or the like may be used.

  Methods for monitoring the number, concentration, and dominance of the bacteria of the Flectobacillus group, Pedobacter group, and Flexibacter sancti group based on genetic information include hybridization homology values for the entire chromosome genome, There are methods based on gene sequences specific to the bacteria of the Fructobacillus family, the Pedobacter family, the Flexibacter sancti family, but the latter Flectobacillus family from the viewpoint that it can be easily and effectively confirmed It is preferable to monitor based on a method based on a gene sequence specific to a bacterial group, a Pedobacter group bacterial group, or a Flexibacter sancti group bacterial group. Specific gene sequence targets include 16S ribosomal RNA gene, 23S ribosomal RNA gene, gyrB gene sequence, spacer region between ribosomal RNA genes, and the like. Among these, it is more preferable to use the sequence of the 16S ribosomal RNA gene from the viewpoint that it is easy to determine a specific gene sequence because there is a lot of published information. In addition, the target of monitoring may be all or part of the bacteria of the Streptococcus group group, the Pedobacter group group, the Flexibacter sancti group, and the Flectobacillus group group or the Pedobacter group. Other bacteria may be included as long as they can monitor the group bacteria and the flexibacter sancti family bacteria. In addition, from the viewpoint of high frequency of appearance and simplicity in troubles, monitoring may be performed only for bacteria that belong to the genus Pedobacter in the “Burge's Manual of Systematic Bacteriology”. Useful.

  When monitoring the dominance of the bacteria of the Flectobacillus family, Pedobacter family, Flexibacter sancti family, for example, reflect the number of all prokaryotes, all bacteria, or bacteria of a certain taxon as much as possible It is better to perform such measurements at the same time and calculate the dominance by the ratio with them.

  As a method for monitoring a specific gene sequence, a known method can be used. For example, a gene specific to Streptococcus group bacteria, Pedobacter group bacteria, Flexibacter sancti group bacteria from gene sequence information can be used. It is preferable in terms of simple detection that a method of selecting a region and using the hybridization efficiency of an oligonucleotide or polynucleotide having the gene sequence can be used. Specifically, using a fluorescent substance, a radioisotope, an enzymatic reporter molecule, an intercalator with electrical activity, etc., using a dot hybridization method, a macroarray method, a microarray method, an in situ hybridization method, etc. Can do. The dot hybridization method, the macroarray method, and the microarray method are more preferable because the detection process is relatively easy to automate. If necessary, gene amplification by polymerase chain reaction (PCR) or the like can be combined with these methods. As the in situ hybridization method, a fluorescence in situ hybridization method (FISH method) using a fluorescently labeled oligonucleotide or a fluorescently labeled polynucleotide can be used. In addition, what is necessary is just to implement a FISH method, enhancing a signal as needed. The detection method using the FISH method may be a method using a fluorescence microscope or a method using a flow cytometer. The dot hybridization method, the macroarray method, and the microarray method include membrane filters or bases of oligonucleotides or polynucleotides having gene sequences specific to the bacteria of the Streptococcus group group, the Pedobacter group group, the Flexibacter sancti group. And a method in which a nucleic acid derived from sludge to be detected is labeled with a fluorescent substance and the like is hybridized.

  As a method of utilizing the hybridization efficiency of oligonucleotides or polynucleotides having a 16S ribosomal RNA gene sequence specific to the bacteria of the Flectobacillus family, the Pedobacter family, the Flexibacter sancti family, Alternatively, a DNA or RNA probe capable of specifically hybridizing with the nucleic acid of the Pedobacter strain group bacteria or the Flexibacter sancti strain group bacteria may be used.

  In addition, as a method for monitoring a specific gene sequence, polymerase chain reaction using a primer DNA having a gene sequence specific to a Fractobacillus strain group bacterium, a Pedobacter strain group bacterium, or a Flexibacter sancti strain group bacterium ( There is also a method of detecting and quantifying by applying PCR). Examples of such methods include a quantitative PCR method in which amplification of nucleic acid is detected in real time using a primer set specific to the bacteria of the family Flectobacillus strains, Pedobacter strains, and Flexibacter sancti strains. It is done. Furthermore, the genomic DNA of microorganisms contained in the sludge mixture is extracted, PCR amplification is performed using a primer set specific to prokaryotes in general, bacteria in general, or a narrower taxonomic group, and the Flectobacillus strain is obtained by electrophoresis. The gene sequences of group bacteria, Pedobacter group bacteria, and Flexibacter sancti group bacteria can also be separated and monitored. As this electrophoresis method, denaturant concentration gradient gel electrophoresis (DGGE) can be used.

  Furthermore, the gene expression characteristics can also be used as a method for monitoring the bacteria of the Fletobacillus group, Pedobacter group, and Flexibacter sancti group. The gene expression characteristics refer to RNA transcription characteristics, protein translation characteristics, and production substance characteristics (for example, expressed protein production substance characteristics) from the genomes of the Flectobacillus lineage bacteria, Pedobacter lineage bacteria, and Flexibacter sancti lineage bacteria. The characteristics of the fungi of Fractobacillus strains, Pedobacter strains, and Flexibacter sancti strains vary greatly depending on the growth conditions such as whether they grow or disperse in flocs. Therefore, it is very useful for the stability of the operation of the membrane separation activated sludge method to track the changes in the properties of the bacteria of the Flectobacillus group, Pedobacter group, and Flexibacter sancti group. By monitoring the characteristics and occurrence troubles in association with each other, it is possible to more accurately predict and detect troubles and take measures at an early stage. The target of gene expression characteristics is not particularly limited, and may be any constituent gene or regulatory gene.

  The target of the RNA transcription characteristic may be either messenger RNA or ribosomal RNA. Various known methods can be used for monitoring these RNA transcription characteristics, such as a method for analyzing the abundance of messenger RNA by hybridization, a method using a DNA chip using an image analyzer, and the like. Is preferred. Also, the FISH method can be used.

  Moreover, the target protein of the protein translation property is not particularly limited, and examples thereof include a morphological change-inducing protein, a dispersed expression protein, and an extracellular polymer-forming protein. As a method for monitoring protein translation characteristics, various known protein analysis methods such as two-dimensional electrophoresis, Western blot, and mass spectrometer can be used.

Furthermore, it is not particularly limited as a target of the product substance characteristics, and examples thereof include extracellularly generated polymers and intracellular components. Examples of methods for monitoring extracellularly produced polymers and intracellular components include methods using a liquid chromatography device, a gas chromatography device, a mass spectrometer, a spectrophotometer, a fluorescence measuring device, a luminescence measuring device, etc. An ELISA method using an antibody-antigen reaction can also be applied.
<Monitoring method for prokaryotes and CFB group bacteria dispersed in sludge mixture>
As the monitoring means / operation control device 7 for monitoring the state of prokaryotes and / or CFB group bacteria present in the sludge mixed solution in the biological reaction tank 1, the prokaryote present in the sludge mixed solution is present. Any device that can efficiently monitor the state of organisms and / or CFB group bacteria can be used. For example, an automatic image recording unit using an image recording unit attached to a microscope and an image analyzing unit thereof can be used. A microscopic observation means can be used after fluorescent staining.

However, because of its simplicity, it is desirable to first detect a sample that efficiently collects microorganisms that are dispersed and present in the sludge mixture. As an example of a sample in which microorganisms present in a dispersed state in a sludge mixed liquid are efficiently collected, a centrifugal supernatant liquid, a filter filtrate, and the like can be considered. This is because the size of microorganisms present in a dispersed state is smaller than the floc of sludge, and therefore, microorganisms present in a dispersed state and other microorganisms can be separated by centrifugation or filter filtration. Specifically, the microorganisms present in a dispersed state are obtained in the supernatant in the case of centrifugation and in the filtrate in the case of filter filtration. The centrifugal supernatant is obtained, for example, by centrifuging the sludge mixed solution at 3000 × g (about 29420 m / s ² ) for 3 minutes, and the filter filtrate is obtained by, for example, filtering through a filter having a pore diameter of 10 μm. . In addition, it can be obtained by filtering with filter paper, non-woven fabric, or glass filter. Specifically, solid-liquid separation means such as a centrifugal separator or a filtration unit may be used.

  Next, a method for monitoring CFB group bacteria dispersed and present in the sludge mixed solution will be described.

  The measurement item for the sample obtained by using the above method or the like is not particularly limited as long as it can efficiently monitor the state of the CFB group bacteria. As a monitoring method, CFB group bacteria can be grown and monitored by a plate culture method using a selective medium. For example, as described below, genetic information, RNA transcription characteristics, protein of CFB group bacteria It is preferable to observe the number, concentration, dominance, and changes in characteristics over time based on the translation characteristics, product characteristics, etc., because it is highly accurate and efficient. More preferably, it is monitored. These monitoring methods can use the same method as the method of monitoring the above-mentioned Fletobacilli strain bacteria, Pedobacter strain group bacteria, and Flexibacter sancti strain group bacteria. Among them, when utilizing the hybridization efficiency of oligonucleotides or polynucleotides having a 16S ribosomal RNA gene sequence specific to CFB group bacteria, a DNA or RNA probe capable of specifically hybridizing with the nucleic acid of CFB group bacteria is used. Use it. For example, the DNA probe “CFB560” (Louis A. O'Sullivan et al., Two persons, Applied and Environmental Microbiology (Appl. Environ. Microbiol.), 2002, volume 68. , P.201-210.). Of course, in addition to this probe, any probe designed to be able to detect CFB group bacteria by hybridization can be used.

<Preferred monitoring method>
These monitoring methods are based on the membrane separation activated sludge method. The membrane permeability is poor due to clogging of the membrane, severe foaming, scum is generated, aeration efficiency is reduced due to increased viscosity, sludge fluidity is reduced, It was developed to solve problems such as problems caused by embrace. These problems are considered to be caused by the appearance of certain specific bacteria, dispersed prokaryotes and CFB group bacteria in the sludge of the membrane separation activated sludge method. The appearance of these microorganisms is that the sludge load in the bioreactor 1 is reduced to 0.15 kg-BOD / kg-VSS in order to obtain an effect of reducing or basically not generating excess sludge as compared with the conventional membrane separation activated sludge method. This is particularly a problem when it is less than / day. The sludge load is further reduced and less than 0.10 kg-BOD / kg-VSS / day, depending on the amount of raw water such as the size of necessity for reducing excess sludge and the conversion rate of soluble organic components contained in raw water. Furthermore, when the amount is less than 0.08 kg-BOD / kg-VSS / day, the appearance of these microorganisms is more likely to be a problem. In order to cope with these problems and to achieve compatibility with the effect of reducing or basically not generating the excess sludge, in the present invention, the state of these microorganisms is monitored by the monitoring means 7, and based on the monitoring results. The action of the filter-feeding micro-animal group is enhanced by the micro-animal addition device and the micro-animal side reaction device. By monitoring these microorganisms, it is possible to predict and detect membrane troubles at an early stage and to take measures while reducing the sludge load and reducing the generation of excess sludge.

  The monitoring method for enhancing the action of the group of micro animals can be selected in consideration of the following way of thinking.

  Regarding the method of monitoring the CFB group bacteria that grow in a dispersed manner, troubles occur when the CFB group bacteria appear in a dispersed state. Therefore, by monitoring the dispersed CFB group bacteria, the CFB group bacteria in the entire sludge can be obtained. The signal that leads to trouble can be grasped with much higher accuracy than monitoring. This is because when detecting CFB group bacteria in the entire sludge, it will also detect useful CFB group bacteria in the floc, so the signal of dispersed CFB group bacteria that actually cause troubles is overlooked. Because it ends up. In general, many CFB group bacteria contribute to the degradation of pollutants such as polysaccharides and the degradation of dead bacteria, and contain many microorganisms that are useful for the membrane separation activated sludge method. By narrowing down the monitoring target to microorganisms that are present in a dispersed manner, the CFB group bacteria can be detected efficiently by making the CFB group bacteria a detection target.

  On the other hand, the methods for detecting the status of specific trouble-related microorganisms in the sludge mixture, Flectobacillus group bacteria, Pedobacter group bacteria, and Flexibacter sancti group bacteria, are actually limited to trouble. Therefore, the entire sludge can be detected as a target even if the detection target is not squeezed and detected in dispersed microorganisms. Furthermore, the fact that the entire sludge can be detected is excellent in that it is possible to monitor the trend from the time when the Flectobacillus strain bacteria are present in the floc without being dispersed.

  However, if the detection target is a limited group of microorganisms in the CFB group bacteria (that is, the bacteria of the Streptococcus group group, the Pedobacter group group, or the Flexibacter sancti group), there is a merit that the sensitivity increases, It becomes necessary to increase the system accordingly. On the other hand, if a method of monitoring CFB group bacteria that grows in a distributed manner based on the discovery that “the bacteria that cause trouble by dispersion is the CFB group bacteria” is used, the detection target is greatly increased to the CFB group bacteria. There is an advantage that the detection system can be simplified. In fact, in the case where bacteria that are present in a dispersed manner are targeted for detection, sufficient accuracy can be obtained by using the normal CFB group bacteria as the detection target. That is, when the detection target range is expanded as much as possible from the viewpoint of simplification and cost reduction within the range where the effect is recognized, the maximum detection target range should be the CFB group bacteria.

  On the other hand, methods for monitoring prokaryotic organisms present in a dispersed manner and methods for monitoring the viscosity and filtration index of a sludge mixed solution are inferior to those described above, but can provide a certain degree of accuracy and preventive effect. Here, the filtration index refers to measured values such as a membrane filtration flow rate, a filtration differential pressure, and a membrane resistance. The membrane filtration flow rate is obtained by measuring the filtration flow rate during constant pressure operation, and the filtration differential pressure is obtained by measuring the filtration differential pressure during constant flow operation. The membrane resistance is obtained by measuring the filtration flow rate per hour by performing constant pressure filtration operation on the collected sludge using a filtration test device for total filtration. Moreover, you may measure the membrane resistance of sludge simply by measuring the filtration rate of the sludge in a filter paper. In this way, the action of the filter-feeding microanimal group is strengthened in response to the detection of a decrease in the filtration flow rate caused by the trouble-related microorganisms and an increase in the filtration differential pressure or membrane resistance. This method can also be employed when simplification of the detection system and cost are a problem. However, the method of monitoring the viscosity and filtration index controls the operating conditions after the viscosity has increased, i.e., it will be dealt with after the membrane permeability has actually been adversely affected. End up. The above-described method for monitoring trouble-related microorganisms is desirable in that the occurrence of trouble can be detected at an earlier stage. Further, the effect of the filter-feeding microanimal is obtained from the fact that the filter-feeding microanimal mainly prey on trouble-related microorganisms as described later. From this, it is possible to apply the present invention more efficiently by limiting the target to troubles caused by trouble-related microorganisms by monitoring trouble-related microorganisms and causing filtration-feeding microanimals to act accordingly. it can.

  As described above, these monitoring methods should be used properly or used together depending on the situation.

<Method for strengthening the action of microanimal groups>
In the present invention, in order to enhance the action of the filter-feeding microanimal group contained in the activated sludge liquid in the biological reaction tank, a filter feeding action enhancing means capable of increasing the amount of the filter-feeding microanimal group is provided. Run intermittently or always. Here, “filtered feeding enhancement means that can increase the amount of filtered feeding microanimals contained in the activated sludge liquid in the biological reaction tank” refers to the filtration contained in the activated sludge liquid in the biological reaction tank. The amount of the feeding microanimal group is increased, and the other aggregate feeding microanimal group is an action enhancing means for the purpose of not increasing or decreasing as much as possible, for example, executing this action enhancing means This is a means for enhancing the filtering feeding action, whereby the amount (increase amount) of the filter-feeding microanimal group that increases as a result can be 1.5 times or more the increase amount of the aggregate-feeding microanimal group.

  Conventionally, in the biological treatment of organic wastewater including the activated sludge method, the effect of micro animals has been described mainly for the purpose of reducing sludge volume and improving the quality of treated water. However, in the membrane-separated activated sludge method, sludge volume reduction and improved treatment water quality are improved compared to the conventional activated sludge method due to the original features of the membrane-separated activated sludge method. The Furthermore, further sludge volume reduction can be performed by operating the BOD sludge load at less than 0.15 kg-BOD / kg-VSS / day. On the other hand, in the membrane separation activated sludge method, particularly in the membrane separation activated sludge method that operates at a BOD sludge load of less than 0.15 kg-BOD / kg-VSS / day, membrane permeability failure, foaming, scum generation, viscosity increase Are often problematic. Even if it tried to utilize a micro animal by the same treatment as the conventional for such a subject, only the effect centered on the micro animal suitable for sludge volume reduction was acquired, and it was not efficient. This is because in the conventional case, any minute animal can be used as long as it is a minute animal that efficiently feeds on sludge. Usually, sludge is composed of flocs that are floating bodies in which microorganisms are aggregated. This is because microanimals that prey on are preferably used. These micro-animals suitable for sludge volume reduction are aggregate-feeding micro-animals that prey mainly on flocs, which are aggregates of microorganisms. As mentioned above, there are, for example, oil worms, nematodes, and caterpillars, as well as some rotifers that prey on flocks.

  In contrast, in the present invention, the action of the filter-feeding microanimal group is particularly enhanced. Membrane separation activated sludge method, especially membrane separation activated sludge method that operates with BOD sludge load less than 0.15 kg-BOD / kg-VSS / day, membrane permeability failure, foaming, scum generation, viscosity increase, etc. This is thought to be caused by the appearance of bacteria dispersed and present in the sludge of the membrane separation activated sludge method. The filter-feeding micro-animal eats bacteria that can be taken into the body through the mouth and filtered by the bacteria associated with the water flow, so it is not a floc that is important for wastewater treatment and has a relatively low involvement in the above problems. It is possible to preferentially remove bacteria that are present in a dispersed manner, which is the cause of the above. By preferentially enhancing the action of these filter-feeding microanimal groups, it is possible to more efficiently solve the problems of the membrane separation activated sludge method than simply enhancing the action of microanimals. is there.

  In the present invention, the enhancement of the action of the filter-feeding microanimal group refers to increasing the amount of the filter-feeding microanimal group in the system. In addition, since there are small animals of various sizes, it is not preferable to evaluate by the number of individuals, the volume occupied by the corresponding minute animals is roughly calculated, and this is handled as the amount of minute animals. Here, it effectively enhances the function of removing dispersed and existing bacteria, which is a problem in the membrane separation activated sludge method, and preferentially removes trouble-related microorganisms that exist in a dispersed state rather than flocs useful for processing. From the viewpoint of maximizing the effects of the present invention, there is provided a filtration feeding enhancement means capable of increasing the increase in the filtration feeding microanimal group to 1.5 times or more of the increase in the aggregate feeding microanimal group. It is preferable to execute intermittently or constantly. More preferably, from the same viewpoint, it is preferable to execute the means for enhancing the filtering feeding action, wherein the increased amount of the filter-feeding microanimal group can be 2.0 times or more of the increase amount of the aggregate-feeding microanimal group. preferable.

  When estimating the volume of the microanimal group, the volume of the microanimal group is calculated by considering the shape of each microanimal species from the size on the plane of each microanimal determined by a stereomicroscope or a phase contrast microscope. In calculating the amount of micro-animals in the system, sampling is appropriately performed from each point in the system, the number of each micro-animal contained in each sample is counted, converted into volume by the method described above, Calculate the volume of each microanimal.

  The enhanced action of the filter-feeding microanimal group is based on the monitoring results of the above-mentioned Fractobacillus group bacteria, Pedobacter group bacteria, Flexibacter sancti group bacteria, and prokaryotes and CFB groups that are dispersed in the sludge mixture. Although it is good to carry out in response to the monitoring result of bacteria, it may be carried out preventively in order to prevent troubles from occurring independently of the monitoring result.

  A specific method for enhancing the action of the filter-feeding microanimal group includes a method of adding the microanimal group into the system. In other words, the filter-feeding microanimal group cultured in advance outside the system, its cysts, and eggs are added to the biological reaction tank. In that case, a pure filtration feeding microanimal of a specific species may be used, or a predominately cultured group of filtering feeding microanimals may be used. In that case, the addition amount of the filter-feeding microanimal group in terms of adults is 1.5 times or more, preferably 2.0 times or more the addition amount of the aggregate-feeding microanimal group. Although the addition place can be performed in the biological reaction tank, it is preferably added to the side reaction tank when a filter-feeding micro-animal side reaction apparatus is provided.

  Further, as a specific method for enhancing the action of the filter-feeding microanimal group, it may be performed by creating a suitable growth environment for the filter-feeding microanimal group. In other words, a carrier or contact material is installed in a biological reaction tank to be a scaffold for filtered feeding micro-animals, or a micro animal side reaction device is installed separately from a biological reaction tank and a carrier or contact material is installed. . These carriers and contact materials are suitable for the growth of filtration-feeding micro-animals such as glass wool, fluid carriers such as porous sponge carriers, activated carbon, and plate-like contact materials made of glass or plastic. Can be used. Among them, a sponge carrier or a plate-like contact material is preferable from the viewpoint of the fixability and cost of the filter-feeding microanimal. Here, as the installation of the contact member having a plate-like structure, for example, one or more glass plates or plastic plates may be immersed in the reaction tank, and at this time, it is preferable to immerse a plurality of sheets at intervals. The interval is preferably 2 mm or more from the viewpoint of fluidity of the liquid in the tank and installation space. At this time, it is preferable that the contact material having such a plate-like structure is not directly exposed to a vigorous gas-liquid mixed flow generated by aeration from an air diffuser installed on the bottom surface in the biological reaction tank. This is because the place where the gas-liquid mixed flow is directly applied is not suitable as a growth environment for the filter-feeding microanimal. For this reason, it is preferable not to place an air diffuser in the lower space of the contact member having a plate-like structure. In the case of a sponge carrier, a gas-liquid mixed flow is not directly applied to the inside of the carrier, so that it is possible to maintain a suitable environment for the growth of filtered feeding animals. However, in order to secure a growth space for the minute animals inside the sponge carrier, it is desirable that the voids present in the sponge carrier have a size having a pore diameter of 0.1 mm or more.

  At this time, it is preferable to inoculate the carrier, contact material, or micro-animal side reaction device to be preliminarily inoculated with a filter-feeding micro-animal group as a seed microorganism. Alternatively, a predominately cultured group of filter-feeding microanimals may be used. In that case, the amount of inoculation of the filter-feeding microanimal group in terms of adults is 1.5 times or more, preferably 2.0 times or more of the amount of inoculation of the aggregate-feeding microanimal group. The operation of the micro-animal side reaction tank is based on the monitoring results of the above-mentioned Flectobacillus group bacteria, Pedobacter group bacteria, Flexibacter sancti group bacteria, and prokaryotic and CFB group bacteria dispersed in the sludge mixture. Control can be performed based on the monitoring result. According to the detection of the microorganism based on the monitoring means, the operation of the membrane separation activated sludge method can be efficiently stabilized by switching the start / stop of the side reaction tank circulation pump and the operation / stop of the side reaction device. It can be done.

  On the other hand, as a method for creating a suitable environment for growth of the filter-feeding microanimal group, dispersed prokaryotes are separated from flocs in the biological reaction tank sludge, and this is separated from the biological reaction tank. It is also possible to adopt a method of supplying to the edible microanimal side reaction device, feeding the filtered feedable microanimal in the side reaction device, and returning it to the biological reaction tank. In order to separate prokaryotes from flocs in biological reaction tank sludge, for example, filtration separation means having an opening of 10 μm to 100 μm can be employed. As a result, flocs are generally removed from the filtrate supplied into the side reaction device, and therefore, in the side reaction device, the filtration feeding microbe is smaller than the aggregate feeding microanimal that mainly eats the floc. Since the animal can maintain a dominant state, the effect of the present invention can be obtained more efficiently. In order to optimize the growth environment of the filter-feeding microanimal in this side reaction device, in addition to using the above-mentioned carrier and contact material, from the viewpoint of energy saving and the preferable environment for growth of the filter-feeding microanimal, It can also be configured with a flow channel-like reaction device that acts on animals.

  This flow channel reactor is composed of a flow channel with a water depth of about 3 mm to 5 cm. The filtrate is supplied from one or more locations, passed through the flow channel, and passed from one or more other locations. An apparatus having a structure for collecting the processing liquid is exemplified. While flowing through this flow path, trouble-causing components are eaten by micro-animals that grow around the bottom of the flow path. A carrier such as a sponge can be installed in the flow path. Filtrate contains almost no floc, so even if it is processed with such a flow-path type device, it will settle out and block the flow-path, and because the water depth is shallow, micro-animals can grow without aeration. Sufficient oxygen supply is possible. Furthermore, since many of the micro animals suitable for this treatment are relatively weak in a vigorous mixing environment, it is effective to use a flow channel reactor from that point of view. This method can also be used when there are relatively few trouble-causing microorganisms. In addition, as described above, it is also possible to inoculate the filter-feeding microanimal group as a seed microorganism in advance, and the operation of the side reaction tank is controlled in the same manner based on the monitoring results described above, so that the membrane can be efficiently used. The operation of the separated activated sludge method can be stabilized.

<Types of micro-animals to act>
Any microanimal group used in the present invention can be used as long as it is filter-feeding in that it can preferentially remove the bacteria present in a dispersed manner that cause the above problems in the membrane separation activated sludge method. However, in order to increase the efficiency and certainty, a filter-feeding microanimal group that excels in predation ability for prokaryotes that grow dispersed in the sludge mixture of the membrane-separated activated sludge method. It is preferable to use, and more preferably, CFB group bacteria that are dispersed and grown in the sludge of the membrane separation activated sludge method, Fectobacillus group bacteria, Pedobacter group bacteria, Flexibacter sancti santi) Filtration perception with excellent predatory ability against bacterial strains A group of edible microanimals should be used. It is desirable to use such a group of filter-feeding micro-animals, although the same filter-feeding micro-animals differ in their feeding habits depending on the species, and all the filter-feeding micro-animals do not necessarily have the same predation ability for certain bacteria. It is not necessarily possessed, and even if the bacteria used as the feed are the same, there are compatibility with the microanimals that prey, so the microanimals do not necessarily have the same feed value.

  Filtration-feeding micro-animals excellent in predatory ability for these bacteria can be obtained by accumulating and acclimatizing these bacteria by supplying them continuously or intermittently. It is also possible to use a microscopic animal isolated using a stereomicroscope and adapted to grow with these bacteria. These bacteria can be collected and used by the method of efficiently collecting the microorganisms dispersed and present in the sludge mixed liquid described above. In addition, CFB group bacteria, Flectobacillus strain group bacteria, Pedobacter strain group bacteria, and Flexibacter sancti strain group bacteria are dispersed from a sludge mixed solution or a sludge mixed solution. Prokaryotes can be isolated from collected samples, and those included in these strains can be selected for classification and used, or the corresponding strains can be obtained from general strain distribution agencies and used.

  In addition, from the viewpoint of efficiently demonstrating the effects of the present invention, the filter-feeding microanimal group used in the present invention includes a daily volume of microanimals when these bacteria are fed into the microanimal group as feed. It is preferable that the number of perished bacteria prey is at least 5 × 10 7 power-bacteria / μL-volume of minute animal / day or more. The number of bacteria prey per minute animal volume per day is calculated from, for example, the number of bacteria supplied to the system, the number of bacteria discharged per day, and the number of animals in the system. Is done.

  On the other hand, when adding a micro animal or inoculating a carrier or a micro animal side reaction tank in advance, it is necessary to prepare a culture of a filter-feeding micro animal. Although the principle is not clear, if the feed is a prokaryote or CFB group bacteria that are dispersed in the sludge mixed liquid, the above-mentioned Flectobacillus group bacteria, Pedobacter group bacteria, Flexibacter sancti group bacteria, As a filter-feeding microanimal, a metazoan can be more stably prepared. From this point, it is preferable to include metazoans as the filter-feeding microanimal group used in the present invention. Similarly, the filtration-feeding microanimal culture solution can be stably prepared, and the above-mentioned bacteria feeding ability and system From the viewpoint of excellent fixing to the inside, it is more preferable to include stag beetles. As the filter-feeding microanimal group used in the present invention, a metazoan or stag beetle is added in an amount that occupies 1.5 times or more, preferably 2.0 or more times that of other microanimal groups. Good.

<Example 1>
(1) First, sludge is collected from a reactor of the membrane separation activated sludge method operating in a laboratory where prokaryotes dispersed and present in the sludge mixture are generated, and 3000 × g (about 29420 m / s ^ 2) Centrifugation for 3 minutes was performed to obtain a supernatant. This supernatant was smeared and cultured on a 3 g / L nutrient broth agar medium, and the appearing colonies were purified and isolated. As a result of 16S ribosomal RNA gene sequencing of these isolates, one of the isolates was a bacterium belonging to the genus Flectobacillus family.

  (2) Next, 5 mL of the aforementioned sludge was put into a test tube, and 5 mL of the isolated Fructobacillus strain group bacterial culture solution washed once with ultrapure water was added to perform shaking culture. Thereafter, for this culture solution, 5 mL of the supernatant of centrifugation (3000 × g, 3 minutes) was removed at a pace of twice a week, and 5 mL of a washed product of the Bacterial culture solution of Flectobacillus strain was added for 2 months. Repeated for a while. A continuous culture system in which a washed product of the Bacterium strain Fractobacillus strain bacterial culture was continuously added was constructed using the obtained micro-animal mixed system as a seed. In this system, filtration-feeding ciliates were the center, and the amount of filtration-feeding ciliates accounted for 2/3 of the micro-animals in the collected samples. As a result of calculating the number of bacterial predation per minute animal volume per day in this system, it was 1 × 10 ^ 8 bacteria / μL-micro animal volume / day, and the trouble-causing microorganisms in the sludge of the membrane separation activated sludge method A filter-feeding microanimal group with excellent predatory ability could be obtained.

  (3) On the other hand, a large number of micro-animals were isolated from a plurality of membrane-separated activated sludges operating in a laboratory using a stereomicroscope, and each of the isolated cultures of the Fructobacillus strain group bacteria was isolated on an 8-well glass slide The washed product was added and cultured. At this time, feeding and water exchange were performed twice a week. Many micro-animals such as filter-feeding ciliates were killed by this operation, but the stag beetles, a kind of filter-feeding micro-metazoans that did not die and grew, grew to more than 10 after 2 weeks. . The culture was scaled up sequentially in a test tube and a flask, and a continuous culture system was finally constructed in which a washed product of the Bacterium flectobacillus strain bacterial culture was continuously added. In this continuous culture tank, a slide glass was placed as a scaffold for micro animals in order to construct a favorable growth environment. A part of the rotifer was swimming, and it was confirmed that a large number grew on the glass surface, and the growth density on the glass surface was 6000 / square centimeter. As a result of calculating the number of bacterial predation per minute animal volume per day in this system, it was 8 × 10 ^ 8 bacteria / μL-micro animal volume / day, and the trouble-causing microorganisms in the sludge of the membrane separation activated sludge method A filter-feeding micrometazoan with excellent predatory ability could be obtained.

  (4) Next, a continuous culture system in which a 1 cm square cubic plastic sponge was introduced as a scaffold for a micro animal in order to construct a suitable growth environment using the flask culture solution of the rotifer obtained in (3). It was constructed. As a result, it was confirmed that some of the rotifers are swimming, and a large number grow on the sponge surface and in the sponge. The growth density in the sponge reached 4 × 10 ^ 5/1 cm square sponge, and a filter-feeding micrometazoan excellent in predation ability of trouble-causing microorganisms in sludge of the membrane separation activated sludge method could be obtained. .

<Comparative Example 1>
(1) From the membrane-separated activated sludge operating in the lab, isolate the veneer worm, which is an aggregate-feeding microanimal, using a stereomicroscope and add the autoclaved sludge on the 8-hole slide glass Culture was performed. As for the veneer earthworm obtained by culturing with this sludge, as a result of culturing with the bacteriophyceae group bacteria as well as the rotifer, the veneer earthworm could not grow. That is, it was judged that this veneer earthworm is not excellent in predatory ability for trouble-causing microorganisms in the sludge of the membrane separation activated sludge method and does not meet the object of the present invention.

  (2) On the other hand, a mouse worm was isolated from a membrane-separated activated sludge operating in a laboratory using a stereomicroscope, and as a result of performing the same test as in the previous section, it could not be cultured depending on the bacteria of the group of Streptococcus strains. . That is, this rat worm was not excellent in predatory ability for trouble-causing microorganisms in the sludge of the membrane separation activated sludge method, and was judged not to meet the object of the present invention.

  (3) Sludge was collected from a membrane separation activated sludge reactor operated in a laboratory, centrifuged at 3000 × g for 3 minutes, and washed with ultrapure water. Shaking culture was performed by putting 5 mL of ultrapure water into 5 mL of this washed sludge in a test tube. Then, about this culture solution, the operation | work which removes 5 mL of centrifugation supernatant liquids and adds 5 mL ultrapure water was repeated twice a week. However, if this operation was continued, the sludge centered on floc was reduced, so 1 out of 4 times of this replacement work was replaced with 2 mL cleaning sludge and 3 mL ultrapure water instead of 5 mL ultrapure water. added. As a result of continuing the culture for two months in this way, the micro-animals in the system were mainly veneer earthworms, caterpillars, rat worms, flagellates and nematodes. As a result of calculating the ratio of the amount of filtered feeding microanimal among these microanimal groups, it was 20%.

<Example 2>
(1) There are three series of laboratory reactors in which a membrane separation device made by modularizing PVDF microfiltration membranes with a pore size of 0.1 μm is immersed in a biological reaction tank with an effective volume of about 1 L, and dextrin-based artificial wastewater with a BOD of 500 ppm is used as a membrane It was processed by the separated activated sludge method. Both reactors have an artificial wastewater residence time of 12 hours in the bioreactor, and the sludge residence time is 1000 days except for the sludge sampling equivalent to 1000 days. Both reactors have a MLSS concentration of about Although it was constant at 24 g / L (BOD sludge load: 0.05 kg-BOD / kg-VSS / day), the viscosity of two of the series increased to 100 mPa · s. The three series of sludge mixed solutions were centrifuged at 3000 × g for 3 minutes, and the bacteria contained in the supernatant were subjected to PCR-DGGE. Bacteria from the Flexibacter sancti family were detected.

  (2) These three series of sludge were once mixed and then divided into three equal parts, and the operation was resumed under the same conditions again. In each series, the membrane filtration pressure difference of the microfiltration flat membrane increased by 6 kPa compared with the normal operation. Here, in two of the series (series A and B), a 20 μm mesh net (mesh rate 14%) is installed in the biological reaction tank to disperse the dispersed bacteria at a flow rate of 200 mL / day. The net filtrate was supplied to a side reaction tank having a volume of 100 mL and aerated. For the remaining one series (series C), the dispersal bacteria were not separated on the net, but the sludge mixture was supplied to a 100 mL side reaction tank at a flow rate of 200 mL / day and aerated. In all three systems, the inflow from the biological reaction tank was pumped back to the biological reaction tank from the secondary reaction tank. Here, with respect to one of the systems performing net filtration (series A), three slide glasses on which stag beetles were grown as in Example 1 (3) were transferred and submerged in the side reaction tank. In addition, for the other (series B), 10 mL of a small animal group centered on a filter-feeding ciliate constructed in Example 1 (2) was added as a seed microorganism to the side reaction tank.

  (3) As a result of continuing the operation under the above conditions, for Series A, in the PCR-DGGE method after 2 weeks, no flexibacterium-Sancti strain bacteria were detected in the centrifugal supernatant, and the filtration differential pressure of the microfiltration membrane was The values recovered during normal operation, and the same improvement was observed for Series B after 3 weeks. On the other hand, as for Series C, flexibacter sancti strain bacteria were detected in the centrifugal supernatant by PCR-DGGE after 3 weeks, and the filtration differential pressure of the microfiltration membrane further increased by 5 kPa.

(4) Subsequently, 10 mL of the micro-animal group shown in Comparative Example 1 (3) was introduced into the series C side reaction tank. However, even after 3 weeks, flexibacter sancti strain bacteria were detected in the centrifugal supernatant in the PCR-DGGE method, and the filtration differential pressure did not recover.
(5) As in the above examples, by strengthening the action of the filter-feeding microanimal group, it was possible to suppress trouble-causing microorganisms that were problematic in the membrane separation activated sludge method.

It is a schematic flowchart which shows one Embodiment of the membrane separation activated sludge process based on this invention.

Explanation of symbols

1. 1. Bioreaction tank 2. Membrane separation device 3. Suction pump Stock solution pump 5. Aeration device 6. Blower 7 7. Monitoring means / operation control device 8. Micro animal addition device Micro animal side reaction device 10. 10. Secondary reaction tank circulation pump Sludge extraction pump 12-13. Control signal

Claims (14)

Organic wastewater containing organic components is supplied to the bioreactor, and the organic wastewater is treated with activated sludge in the bioreactor and purified by submerged membrane separation equipment installed in the bioreactor. In the membrane-separated activated sludge treatment method for extracting water, the filtration feeding enhancement means that can increase the amount of filtered feeding microanimals contained in the activated sludge liquid in the biological reaction tank is intermittently or constantly executed. An organic wastewater treatment method comprising: The organic wastewater treatment method according to claim 1, wherein the filter-feeding microanimal group is a microanimal group having a high predatory ability for prokaryotes that are dispersed and grown in the activated sludge liquid in the biological reaction tank. The organic wastewater treatment method according to claim 2, wherein the prokaryote that is dispersed and grown in the activated sludge liquid is a CFB group bacterium that is dispersed and grown in the activated sludge liquid. The filter-feeding microanimal group has a high predatory capacity for at least one of the bacteria of the Flectobacillus family, the Pedobacter family, and the Flexibacterium sacti family The organic wastewater treatment method according to claim 1, which is a group of micro animals. The viscosity and / or filtration index of the activated sludge liquid in a biological reaction tank is measured intermittently or constantly, and the filter feeding effect enhancing means is executed according to the measurement result. Organic wastewater treatment method. Dispersed in the activated sludge contained in the activated sludge solution in the bioreactor, the bacteria in the group of Flectobacillus, the bacteria in the Pedobacter group, the bacteria in the Flexibacter sancti group, and the activated sludge The organic substance according to any one of claims 1 to 4, wherein at least one state of prokaryotic organisms that grow as a result of measurement is intermittently or constantly measured, and the filtering feeding effect enhancing means is executed according to the measurement result. Wastewater treatment method. The filtering feeding enhancement means adds a substance containing a filtering feeding microanimal group as a main component into the biological reaction tank, and / or a carrier or contact material for the filtering feeding microanimal group is added to the biological reaction tank. The organic wastewater treatment method according to any one of claims 1 to 6, which is to be installed inside. The organic wastewater treatment method according to any one of claims 1 to 7, wherein the filter-feeding microanimal group is a filter-feeding microanimal group including metazoans. The organic wastewater treatment method according to claim 8, wherein the metazoan is a stag beetle. The organic wastewater treatment method according to any one of claims 1 to 9, wherein a BOD sludge load in the biological reaction tank is less than 0.15 kg-BOD / kg-VSS / day. Membrane separation activity comprising a biological reaction tank for storing organic wastewater and treating activated sludge, and a submerged membrane separation membrane installed in the biological reaction tank for solid-liquid separation treatment of activated sludge liquid A sludge treatment apparatus comprising a filtration feeding microanimal group addition means and / or a side reaction tank for filtering feeding microanimal that adds a filter feeding microanimal group to a biological reaction tank, and / or filtration A membrane-separated activated sludge treatment apparatus for organic wastewater, characterized in that a carrier and contact material for feeding microanimals are installed in a biological reaction tank. Means for intermittently or constantly measuring the viscosity and / or filtration index of the activated sludge liquid in the biological reaction tank, and based on the measured viscosity and / or the level of the filtration index The membrane separation activated sludge treatment apparatus for organic wastewater according to claim 11, further comprising means for determining whether the group addition means can be executed. Dispersed in the activated sludge contained in the activated sludge solution in the bioreactor, the bacteria in the group of Flectobacillus, the bacteria in the Pedobacter group, the bacteria in the Flexibacter sancti group, and the activated sludge Means for intermittently or constantly measuring the state of at least one of the prokaryotes that grow on the basis of the measured viscosity and / or level of filtration index, The membrane separation activated sludge treatment apparatus for organic wastewater according to claim 11, further comprising means for determining whether or not the addition means can be executed. A micro-animal-containing liquid containing a filter-feeding microanimal group collected from an activated sludge solution, or a filter-feeding microanimal group isolated from an activated sludge solution is converted into a Fectobacillus strain group bacterium, Pedobacter ) Acclimatized by at least one of the phylogenetic group bacteria, the Flexibacter sancti family group bacteria, and the prokaryote that grows dispersed in the activated sludge solution, thereby increasing the number of filter-feeding microanimals. A method for producing a filter-feeding microanimal preparation characterized by producing an additive containing the same.

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