JP2016002541A - Membrane separation activated sludge treatment apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a membrane separation activated sludge treatment apparatus and method that can perform aerobic treatment and anoxic treatment of water to be treated in a limited space, and can miniaturize the size of the treatment apparatus.SOLUTION: A membrane separation activated sludge treatment apparatus 1 comprises: a treatment tank 10 that is a single tank type and has an airtight structure; membrane separation units 20A, 20B; aeration means (22A, 22B, 102A, 102B, 24); first piping 110 that supplies outside air to the aeration means; and second piping 120 that circulates and supplies gas in a gas phase G. A membrane separation activated sludge treatment method alternately performs aerobic treatment comprising a step of opening a flow passage in the first piping 110 and a step of diffusing air into water to be treated to biologically treat the water to be treated under an aerobic condition, and anoxic treatment comprising a step of opening a flow passage in the second piping 120 and a step of diffusing the gas in the gas phase G into the water to be treated to biologically treat the water to be treated under an anoxic condition.

Description

  The present invention relates to a membrane separation activated sludge treatment apparatus and a membrane separation activated sludge treatment method for performing activated sludge treatment and membrane separation treatment using an ultrafiltration membrane, a microfiltration membrane or the like.

  In the membrane separation activated sludge method, the treated water is biologically treated with activated sludge, and then the treated water and activated sludge are separated into membranes using a separation membrane such as an ultrafiltration membrane and a microfiltration membrane. This is a treatment method for separating and removing activated sludge from water. Membrane separation activated sludge treatment equipment that performs water treatment using the membrane separation activated sludge method replaces the solid-liquid separation treatment by the precipitation of the conventional activated sludge treatment with membrane separation treatment, such as a sedimentation basin that requires a large space. It is possible to adopt a device configuration in which installation is omitted. Moreover, since activated sludge is separated by external force using a separation membrane, the activated sludge concentration in the reaction tank can be set high in the treatment. Therefore, the membrane separation activated sludge treatment apparatus can be reduced in size, and is spreading as a water treatment apparatus suitable for space saving.

  As a form of the membrane separation activated sludge treatment apparatus, the membrane separation unit is installed in a tank different from the treatment tank that performs biological reaction treatment with activated sludge, or is installed in a stand-alone form outside the treatment tank. Alternatively, there is an aerobic tank integrated type installed in the aerobic tank. For example, the aerobic tank integrated type is operated such that air is diffused to maintain the processing tank in an aerobic condition and to perform physical cleaning of the membrane separation unit. On the other hand, an anaerobic tank-integrated form in which the membrane separation unit is installed in the anaerobic tank has also been proposed.

  For example, in Patent Document 1, a water treatment apparatus provided with a membrane cartridge for membrane separation of water to be treated inside a treatment tank, and provided with a diffuser for ejecting a membrane surface cleaning gas below the membrane cartridge, The treatment tank is formed in a hermetically sealed manner, provided with a circulation means for circulating and supplying exhaust gas staying in the upper space in the tank to the aeration means, and an oxygen-free film surface cleaning gas containing exhaust gas is ejected from the aeration means A water treatment apparatus configured to perform membrane separation of water to be treated under conditions is disclosed.

  Moreover, in patent document 2, in the biological treatment apparatus which has the biological treatment tank with which the activated sludge or microbial membrane which is sealed and is in an oxygen-free or anoxic condition is mixed, and the separation membrane immersed in this tank, An air diffuser that blows oxygen-free or oxygen-poor gas under the separation membrane in the treatment tank is provided, and the air in the oxygen-free or oxygen-poor gas tank separately provided in communication with the gas diffuser and the treatment tank is provided. A biological treatment apparatus that communicates with a phase section is disclosed.

JP-A-9-141291 Japanese Patent No. 3234139

  In the membrane separation activated sludge treatment apparatus, when adopting an aerobic tank integrated type in which the membrane separation unit is installed in the aerobic tank, a configuration in which biological reaction treatment with activated sludge is performed in a single tank of the aerobic tank; By doing so, it is possible to realize a processing apparatus mainly for organic substances, and it is also possible to reduce the scale of the processing apparatus. However, in a configuration in which only aerobic treatment is performed in a single tank composed only of aerobic tanks, alkalinity is consumed by the nitrification reaction using ammonia nitrogen contained in the water to be treated as a substrate. There is a problem that an alkali agent needs to be frequently added for adjustment. In order to improve the quality of treated water in conjunction with downsizing of the treatment equipment scale, a treatment method that performs both aerobic treatment and oxygen-free treatment, removes nitrogen, and supplements alkalinity by denitrification reaction in oxygen-free treatment Is suitable.

  On the other hand, in the case of adopting an anaerobic tank integrated type in which the membrane separation unit is installed in the anaerobic tank, there is a problem that the scale of the processing apparatus is increased with the addition of a separate processing tank. For example, the water treatment device disclosed in Patent Document 1 is a device that separates biologically treated water and the like after biological treatment so that NOx and the like are not increased by oxygen dissolved in water to be treated. It is necessary to provide an aerobic tank separately. Moreover, in the biological treatment apparatus disclosed by patent document 2, it is required to provide the tank used for gas introduction separately from the treatment tank. Furthermore, when installing such a separate tank, a piping system for transferring activated sludge or nitrification liquid separated and recovered by membrane separation is required, which greatly hinders space saving of the apparatus. .

  Therefore, the present invention can perform the aerobic treatment and the oxygen-free treatment of the water to be treated in a limited space, and the membrane separation activated sludge treatment device and the membrane separation activity that can reduce the scale of the treatment device. It aims at providing the sludge treatment method.

  In order to solve the above problems, a membrane separation activated sludge treatment apparatus according to the present invention is a single tank type membrane separation activated sludge treatment apparatus that performs biological reaction treatment with activated sludge in a single tank, and is treated with activated sludge. A treatment tank having an airtight structure for performing biological reaction treatment, a membrane separation unit installed in the treatment tank for performing solid-liquid separation treatment of treated water and the activated sludge, installed in the treatment tank, and Aeration means for physically irrigating the treated water and physically cleaning the membrane separation unit; a first pipe for supplying outside air to the aeration means; and a gas phase section in the treatment tank for the aeration means. And a second pipe that circulates and supplies gas, and the opening and closing of the flow path in the first pipe and the opening and closing of the flow path in the second pipe are switched.

  Further, the membrane separation activated sludge treatment method according to the present invention is a single tank type membrane separation activated sludge treatment method in which biological reaction treatment with activated sludge is performed in a single tank, and biological treatment treatment of water to be treated with activated sludge. A treatment tank having an airtight structure, a membrane separation unit installed in the treatment tank for performing solid-liquid separation treatment of treated water and the activated sludge, installed in the treatment tank, and supplying gas to the treated water An air diffuser that diffuses air and physically cleans the membrane separation unit, a first pipe that supplies outside air to the air diffuser, and a gas in a gas phase section in the processing tank is circulated and supplied to the air diffuser. In a membrane separation activated sludge treatment apparatus comprising a second pipe, the step of opening the flow path in the first pipe and closing the flow path in the second pipe, and the air diffuser through the first pipe Supply air and by the diffuser means Aerobic treatment comprising the steps of diffusing air into the water to be treated in the treatment tank and biologically treating the water to be treated under aerobic conditions, and closing the flow path in the first pipe And a step of opening a flow path in the second pipe, and supplying gas in a gas phase portion in the processing tank through the second pipe to the air diffuser, and the gas diffuser in the process tank The living thing by the activated sludge of the to-be-treated water while alternately performing an oxygen-free treatment comprising the step of aerating the gas to the to-be-treated water and subjecting the to-be-treated water to a biological reaction treatment under anoxic conditions In addition to performing a reaction process, the membrane separation unit performs a solid-liquid separation process between the biological reaction process treated water and the activated sludge.

  According to the present invention, an aerobic treatment and an oxygen-free treatment of water to be treated can be carried out in a limited space, and a membrane separation activated sludge treatment device and membrane separation activity that can reduce the size of the treatment device. A sludge treatment method can be provided.

It is a figure which shows an example of a structure of the membrane separation activated sludge processing apparatus which concerns on one Embodiment of this invention. It is a figure which shows the state of the membrane separation activated sludge processing apparatus in the aerobic treatment which concerns on the membrane separation activated sludge processing method which concerns on one Embodiment of this invention. (A) is a figure which shows switching of opening and closing of a valve | bulb, (b) is a figure which shows the flow of the gas diffused. It is a figure which shows the state of the membrane separation activated sludge processing apparatus in the oxygen-free process which concerns on the membrane separation activated sludge processing method which concerns on one Embodiment of this invention. (A) is a figure which shows switching of opening and closing of a valve | bulb, (b) is a figure which shows the flow of the gas diffused. It is a figure which shows an example of a structure of the membrane separation activated sludge processing apparatus which concerns on Example 1 of this invention. It is a figure which shows the fluctuation | variation of the amount of treated water and the amount of inflow water in the membrane separation activated sludge processing apparatus which concerns on Example 1 of this invention. It is a figure which shows an example of a structure of the combination of the membrane-separation activated sludge processing apparatus and coagulation-separation apparatus which concern on Example 2 of this invention. It is a figure which shows the fluctuation | variation of the amount of treated water and the amount of inflow water in the combination of the membrane separation activated sludge processing apparatus and coagulation separation apparatus which concern on Example 2 of this invention. It is a figure which shows an example of a structure of the combination of the membrane-separation activated sludge processing apparatus and coagulation-separation apparatus which concern on Example 3 of this invention. It is a figure which shows the fluctuation | variation of the amount of treated water and the amount of inflow water in the combination of the membrane separation activated sludge processing apparatus and coagulation separation apparatus which concern on Example 3 of this invention.

  Hereinafter, a membrane separation activated sludge treatment apparatus and a membrane separation activated sludge treatment method according to an embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the common part in each figure, and description about the overlapping part is abbreviate | omitted.

  FIG. 1 is a diagram showing an example of the configuration of a membrane separation activated sludge treatment apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, the membrane separation activated sludge treatment apparatus 1 according to this embodiment mainly includes a treatment tank 10, membrane separation units (20 </ b> A, 20 </ b> B), and aeration means (22 </ b> A, 22 </ b> B, 102 </ b> A, 102 </ b> B). 24), a first pipe 110, and a second pipe 120. The membrane separation activated sludge treatment apparatus 1 is a single tank type membrane separation activated sludge treatment apparatus that performs biological reaction treatment with activated sludge in a single tank. That is, only a single tank is provided with a treatment tank (treatment tank 10) that performs biological reaction treatment of water to be treated with activated sludge, and a biological reaction different from that of the treatment tank 10 is provided immediately before and immediately after the treatment tank 10. No tank for processing is installed. In the treatment tank 10 that is a single tank, the aerobic treatment and the oxygen-free treatment are switched by switching the opening and closing of the gas flow path in the first pipe 110 and the opening and closing of the gas flow path in the second pipe 120. It is set as the structure.

  The treatment tank 10 is a tank that performs biological reaction treatment of water to be treated with the activated sludge retained. The treatment tank 10 has an airtight structure in which the airtightness of the internal space is enhanced, and a structure in which the movement of gas between the inside and the outside air is remarkably restricted except through various pipes and the like. Has been. As shown in FIG. 1, untreated raw water is introduced as treated water inside the treatment tank 10 to form a water phase portion L, and a gas phase portion G remains above the water phase portion L. . In this gas phase portion G, low oxygen air or the like in which oxygen has been consumed by activated sludge respiration, nitrification reaction, organic matter oxidative decomposition reaction, etc. migrates from the water phase portion L and stays there.

  The membrane separation units (20A, 20B) are installed in a state of being immersed in the water phase portion L of the treatment tank 10. The membrane separation activated sludge treatment apparatus 1 according to the present embodiment includes two types of membrane separation units 20A and 20B, but may include one or three or more types of membrane separation units. Good. The membrane separation unit (20A, 20B) is a submerged membrane separation device that performs membrane separation treatment (solid-liquid separation treatment) between treated water and activated sludge, and comprises a membrane module that performs membrane separation treatment and water to be treated. A suction pump (not shown) for suction and various pipes are used. The membrane module is composed of a plurality of membrane elements mainly composed of separation membranes such as ultrafiltration membranes, microfiltration membranes, etc., and is a flat membrane membrane module having a flat membrane-like separation membrane, a hollow fiber shape A hollow fiber membrane module or the like provided with the above separation membrane can be applied.

  The flat membrane type membrane module takes, for example, a form in which a plurality of membrane elements each having a flat membrane-like separation membrane and a frame that supports the separation membrane are arranged in parallel inside the casing. An intermembrane flow path is formed between the plurality of membrane elements, and the upper end of the intermembrane flow path is connected to the treated water pipe 190. The flat membrane type membrane module can be installed in a single stage or in a plurality of layers so that the flow paths between the membranes are continuously connected in the vertical direction. On the other hand, the hollow fiber membrane module takes, for example, a form in which a plurality of membrane elements each formed by concentrating a plurality of hollow fiber-like separation membranes and being fixed to a water collecting member are disposed inside the casing. An intermembrane flow path is formed between the converged hollow fiber-like separation membranes, and the opening at the end of each separation membrane is connected to the treated water pipe 190 through the water collection chamber inside the water collection member. The

  In the membrane separation units 20A and 20B, the water to be treated and the activated sludge are subjected to membrane separation treatment by a cross flow filtration method or a total amount filtration method by suctioning the water to be treated by a suction pump (not shown). The activated sludge that has been subjected to membrane separation remains in the aqueous phase L of the treatment tank 10 and is maintained at a high level of activated sludge, while being treated with biological reaction and treated with the activated sludge separated. Is drained out of the system through the treated water piping 190.

  The treatment tank 10 is provided with an air diffuser that diffuses gas into the water to be treated and physically cleans the membrane separation units 20A and 20B. The air diffuser includes air diffusers 22A and 22B, air supply tubes 102A and 102B, and a blower 24, and is provided for each of the two membrane separation units 20A and 20B. The diffuser tubes 22A and 22B for performing gas diffusion are installed so as to be positioned below the membrane separation units 20A and 20B, and are connected to the blower 24 via the air supply tubes 102A and 102B, respectively. That is, the gas supplied by the blower 24 flows through the air supply pipes 102A and 102B, and is diffused from the air diffusion pipes 22A and 22B.

  Since the diffuser tubes 22A and 22B are installed below the membrane separation units 20A and 20B, the gas diffused from the diffuser tubes 22A and 22B rises through the intermembrane flow paths of the membrane separation units 20A and 20B. As a result, an upward flow of the water to be treated is generated by the air lift effect. Therefore, a circulation flow of the water to be treated that rises inside the membrane separation units 20A and 20B and descends outside is generated, so that the dissolution of the gas into the water to be treated and the agitation and stirring of the water to be treated are efficiently performed. It will be.

  The gas rising in the intermembrane flow paths of the membrane separation units 20A and 20B forms a cross-flow gas-liquid two-phase flow with respect to the membrane surface of each membrane element. Each membrane element is designed to physically wash the membrane surface by peeling off deposits derived from activated sludge metabolites and impurities in the water to be treated by the shear force exerted by the gas-liquid two-phase flow. .

  The 1st piping 110 is connected to the aeration means (blower 24). The first pipe 110 communicates with the outside of the system of the membrane separation activated sludge treatment apparatus 1 and forms a flow path for supplying outside air, that is, air from outside the system to the air diffuser (blower 24). The first pipe 110 is provided with a first pipe valve V10 that switches between opening and closing the flow path in the first pipe 110.

  On the other hand, the second pipe 120 connects between the air diffusion means (blower 24) and the circulation air supply hole 140. The circulation air supply hole 140 is provided on the upper side of the processing tank 10 and communicates between the gas phase portion G of the processing tank 10 and the second pipe 120. Therefore, a gas flow path is formed between the air diffusion means (blower 24) and the gas phase part G of the processing tank 10 by the second pipe 120 and the circulation air supply hole 140. That is, the gas in the gas phase part G of the processing tank 10 is circulated and supplied from the gas phase part G of the processing tank 10 to the air diffuser (blower 24) through the circulation air supply hole 140. The second pipe 120 is provided with a second pipe valve V20 that switches between opening and closing the flow path in the second pipe 120.

  Further, the treatment tank 10 is provided with an exhaust hole 150. The exhaust hole 150 is provided on the upper side of the processing tank 10 and communicates the gas phase part G of the processing tank 10 with the outside of the processing tank 10. The exhaust hole 150 is provided with an exhaust hole valve V30 for switching between opening and closing of the flow path.

  The treatment tank 10 is provided with aeration means for aeration of the water to be treated. The aeration means includes an air diffuser 32, an air supply pipe 170, and a blower 34. The air diffuser 32 is installed in an area where the membrane separation units 20A and 20B are not disposed above the air diffuser 170. It is connected to the blower 34 via The blower 34 is supplied with air from outside the system of the membrane separation activated sludge treatment apparatus 1. Therefore, the air supplied by the blower 34 flows through the air supply pipe 170 and is diffused from the air diffusion pipe 32.

  Further, a dissolved oxygen concentration meter 40 is installed in the treatment tank 10. By measuring the dissolved oxygen concentration of the water to be treated by the dissolved oxygen concentration meter 40, the amount of aeration can be adjusted. For example, when the biological reaction process is performed in the treatment tank 10 under an aerobic condition, the amount of air diffused (aeration amount) by the air diffuser (22A, 22B, 102A, 102B, 24) is the water to be treated. It is possible to grasp whether or not the necessary amount is reached with respect to organic load and nitrogen load. Therefore, the operation and stop of the aeration means (32, 170, 34) or the aeration output can be controlled according to the amount of aeration by the aeration means (22A, 22B, 102A, 102B, 24). In the aerobic treatment, when the dissolved oxygen concentration equal to or higher than the set value is measured for a predetermined time or longer, the aeration means (32, 170, 34) is used to keep the dissolved oxygen concentration constant. Stopped.

  In the membrane separation activated sludge treatment apparatus 1 having such a configuration, when the first piping valve V10 is opened and the second piping valve V20 is closed, the air diffuser (22A, 22B, 102A, 102B, 24). However, the air supplied from outside the system of the membrane separation activated sludge treatment apparatus 1 through the first pipe 110 can be diffused. When the oxygen-containing air is diffused into the water to be treated, the atmosphere in the treatment tank 10 can be transferred to an aerobic condition, and the water phase portion L of the treatment tank 10 is agitated and agitated. It is possible to physically wash 20A and 20B. At this time, the pressure of the gas phase portion G that has risen due to air diffusion can be released by opening the exhaust valve V30.

  Further, when the first piping valve V10 is closed and the second piping valve V20 is opened, the air diffuser (22A, 22B, 102A, 102B, 24) is passed through the second piping 120 to the gas in the processing tank 10. The gas circulated and supplied from the phase part G can be diffused. When the gas in the gas phase part G of the treatment tank 10 is diffused into the water to be treated, the atmosphere in the treatment tank 10 can be shifted to an oxygen-free condition and the aqueous phase L of the treatment tank 10 is diffused. It is possible to physically wash the membrane separation units 20A and 20B by stirring. At this time, by closing the exhaust valve V30, the circulated gas can be maintained at a low oxygen concentration.

  Therefore, according to the membrane separation activated sludge treatment apparatus 1, the aerobic treatment and the oxygen-free treatment of the water to be treated can be carried out only in the treatment tank 10, and physical washing of the membrane separation units 20A and 20B is preferred. It can be continued during both the gas treatment and the oxygen-free treatment. Therefore, a single tank type biological reaction treatment and membrane separation treatment can be performed continuously, and the membrane separation activated sludge treatment apparatus capable of reducing the scale of the treatment apparatus is obtained.

  Next, the membrane separation activated sludge treatment method according to this embodiment will be described.

  The membrane separation activated sludge treatment method according to this embodiment makes it possible to continuously perform biological reaction treatment with activated sludge of water to be treated and membrane separation treatment between treated water and activated sludge of biological reaction treatment. It is a processing method. This membrane-separated activated sludge treatment method is similar to the membrane-separated activated sludge treatment apparatus 1 described above, in the treatment tank 10, membrane separation units (20A, 20B), and aeration means (22A, 22B, 102A, 102B, 24). And it can carry out suitably in a processing device provided with the 1st piping 110 and the 2nd piping 120.

  In the membrane separation activated sludge treatment method according to the present embodiment, organic matter contained in the water to be treated by performing a single tank type anaerobic aerobic activated sludge process in which a biological reaction process using activated sludge is performed in a single tank, Other organic nitrogen, inorganic nitrogen, etc. are treated. An oxygen-free aerobic activated sludge treatment in a single tank consists of an aerobic treatment in which treated water is subjected to biological reaction treatment under aerobic conditions and an anaerobic treatment in which treated water is subjected to biological reaction treatment under anoxic conditions. It is performed repeatedly alternately.

  FIG. 2 is a diagram illustrating a state of the membrane separation activated sludge treatment apparatus in the aerobic treatment according to the membrane separation activated sludge treatment method according to the embodiment of the present invention. (A) is a figure which shows switching of opening and closing of a valve | bulb, (b) is a figure which shows the flow of the gas diffused.

The aerobic treatment includes an air flow path opening step and an aerobic biological reaction treatment step. In the aerobic treatment, mainly nitrification reaction that oxidizes ammonia nitrogen (NH ₄ -N) contained in the water to be treated to nitrate nitrogen (NO ₃ -N) and aerobic decomposition of various organic substances. An aerobic decomposition reaction. In addition, in FIG. 2, although illustration is abbreviate | omitted about the flow of the to-be-processed water by which a biological reaction process is performed, and the flow of the to-be-processed membrane separation process, introduction of the to-be-processed water to the membrane separation activated sludge processing apparatus 1 is carried out. And the drainage of the treated water from the membrane separation activated sludge treatment apparatus 1 is made continuously.

  In the air flow path opening step, as shown in FIG. 2A, while the flow path in the first pipe 110 that supplies air to the air diffuser (blower 24) is opened (first pipe valve V10: open). The flow path in the second pipe 120 that circulates and supplies the gas in the gas phase G in the processing tank 10 to the air diffuser (blower 24) is closed (second pipe valve V20: closed). Further, the exhaust hole 150 of the processing tank 10 is opened (exhaust hole valve V30: open) so that the gas phase part G of the processing tank 10 communicates with the outside of the system. As a result, the gas phase part G in the treatment tank 10 having an airtight structure becomes an open space, and it is possible to appropriately diffuse air supplied from outside the system.

  In the aerobic biological reaction treatment process, as shown in FIG. 2B, air is supplied to the air diffuser (blower 24) via the first pipe 110, and the air diffuser (air diffuser tubes 22A and 22B) performs the treatment. Air is diffused into the water to be treated in the tank 10, and the water to be treated is subjected to biological reaction treatment under aerobic conditions. As a result, the aerobic decomposition reaction and the nitrification reaction of the water to be treated proceed, and the membrane separation units 20A and 20B are physically cleaned by the diffused air. In this step, aeration by the aeration means (32, 170, 34) can also be performed. It is possible to maintain the dissolved oxygen concentration necessary for the aerobic decomposition reaction and the nitrification reaction by supplementing the amount of oxygen that is insufficient only by the aeration from the aeration tubes 22A and 22B. The diffused air is exhausted from the exhaust hole 150 after oxygen is consumed by the activated sludge and moves to the gas phase part G.

  FIG. 3 is a diagram showing a state of the membrane separation activated sludge treatment apparatus in the oxygen-free treatment according to the membrane separation activated sludge treatment method according to the embodiment of the present invention. (A) is a figure which shows switching of opening and closing of a valve | bulb, (b) is a figure which shows the flow of the gas diffused.

The oxygen-free treatment includes a circulation flow path opening step and an oxygen-free biological reaction treatment step. In the oxygen-free treatment, a denitrification reaction is mainly performed in which nitrate nitrogen (NO ₃ —N) contained in the water to be treated is reduced to nitrogen gas (N ₂ ). In addition, in FIG. 3, although the illustration about the flow of the to-be-processed water subjected to biological reaction treatment and the flow of the treated water subjected to membrane separation treatment is omitted, introduction of the to-be-treated water into the membrane separation activated sludge treatment apparatus 1 And the drainage of the treated water from the membrane separation activated sludge treatment apparatus 1 is made continuously.

  In the circulation flow path opening step, as shown in FIG. 3A, the flow path in the first pipe 110 that supplies air to the air diffuser (blower 24) is closed (first pipe valve V10: closed). The flow path in the second pipe 120 that circulates and supplies the gas in the gas phase portion G in the processing tank to the air diffuser (blower 24) is opened (second pipe valve V20: open). Further, the exhaust hole 150 of the processing tank 10 is closed (exhaust hole valve V30: closed) so that the gas phase part G of the processing tank 10 is shut off from outside the system. As a result, the gas phase portion G in the treatment tank 10 having an airtight structure becomes a closed space, and an increase in oxygen concentration due to air contamination is prevented.

  In the anaerobic biological reaction treatment process, as shown in FIG. 3B, the gas in the gas phase portion G in the treatment tank 10 is supplied to the air diffuser (blower 24) via the second pipe 120 to diffuse the air. By means (aeration tubes 22A, 22B), the gas in the gas phase G in the treatment tank 10 is diffused into the treatment water in the treatment tank 10, and the treatment water is subjected to biological reaction treatment under anoxic conditions. As a result, the denitrification reaction of the water to be treated proceeds, and the membrane separation units 20A and 20B are physically cleaned by the diffused gas. The diffused gas is circulated and supplied into the treatment tank 10 through the circulation air supply hole 140, the second pipe 120, and the air diffusion means (22A, 22B, 102A, 102B, 24) in this order. Since the oxygen concentration of the circulated gas gradually decreases as oxygen is consumed by the activated sludge, the atmosphere in the treatment tank 10 is maintained in the aerobic treatment by continuing the aeration for a predetermined time. It will shift from conditions to anoxic conditions. In this step, the aeration means (32, 170, 34) is not operated.

  Switching control between the aerobic treatment and the oxygen-free treatment can be realized by timer control or automatic measurement of treated water quality. For example, nitrification rate, denitrification rate, raw water nitrogen component (total nitrogen, ammonia nitrogen, nitrate nitrogen, nitrite nitrogen) concentration, total phosphorus concentration, BOD, COD, MLSS (concentration), SS (concentration) ) Design the treatment time ratio of aerobic treatment and oxygen-free treatment based on turbidity and water temperature, and about air diffuser (blower 24), first piping valve V10, second piping valve V20, exhaust hole valve V30, etc. By setting the timer to switch the operation at a predetermined processing time ratio, continuous processing that alternately repeats aerobic processing and oxygen-free processing can be performed. In addition, for example, the quality of treated water (total nitrogen, ammonia nitrogen, nitrate nitrogen, BOD, COD, etc.) is automatically measured, and aerobic treatment and oxygen-free treatment are repeated alternately according to the target treated water quality. Automatic control is also possible.

  According to such a membrane separation activated sludge treatment method, aerobic treatment and anoxic treatment are alternately repeated to continuously remove organic matter by aerobic decomposition reaction and nitrogen removal by a series of nitrification reaction and denitrification reaction. Can be done automatically. During the continuous treatment, since the alkalinity consumed in the nitrification reaction is compensated by the denitrification reaction, there is an advantage that the addition of alkali for adjusting the pH can be reduced or omitted. As a single tank type activated sludge treatment method, an oxidation ditch method, an intermittent aeration activated sludge method, and the like are conventionally known. In general, the oxidation ditch method tends to have a trade-off relationship between downsizing of the apparatus and the formation of a stable oxygen-free state. The intermittent aerated activated sludge method shifts to an oxygen-free state by stopping aeration. Since it takes a long time to adjust, it is difficult to adjust the anaerobic aerobic ratio according to the load fluctuation. On the other hand, in the membrane separation activated sludge treatment method according to the present embodiment, an aerobic treatment and an anaerobic treatment can be performed in a limited space of a single tank type. By circulating and diffusing a low oxygen concentration gas present in the gas phase portion G of 10, it is possible to quickly shift the anoxic state or continuously operate the membrane separation unit. Therefore, it is a water treatment method suitable for downsizing the treatment apparatus.

  The membrane separation activated sludge treatment apparatus and the membrane separation activated sludge treatment method according to the present embodiment as described above perform biological reaction treatment with activated sludge of water to be treated while alternately performing aerobic treatment and oxygen-free treatment, Membrane separation treatment between treated water and activated sludge is performed. As a result, advanced water treatment based on oxygen-free aerobic treatment and high activated sludge concentration can be realized in a limited space. Therefore, even when a flocculating / separating device that performs flocculating / separating treatment of water to be treated is arranged in parallel to the processing tank, it is possible to construct a small membrane-separated activated sludge processing device that saves space. That is, a part of the water to be treated is distributed and introduced into the coagulation / separation apparatus, and after the coagulation / separation process is completed, the membrane separation activated sludge treatment apparatus 1 can be remixed with the treated water treated with activated sludge. . The aggregation separation process is used for the peak cut process. Such a membrane separation activated sludge treatment device is a mixed treatment water that is a mixture of a membrane separation activated sludge method that provides high-quality treated water and a treatment water obtained from a coagulation sedimentation method that is a simple treatment. It is a system that satisfies the quality standards of discharged water.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples of the present invention, but the present invention is not limited thereto.

[Example 1]
FIG. 4 is a diagram illustrating an example of the configuration of the membrane separation activated sludge treatment apparatus according to Embodiment 1 of the present invention.

  As shown in FIG. 4, the first embodiment includes the processing tank 10, membrane separation units 20 </ b> A and 20 </ b> B, aeration means 22 </ b> A, 22 </ b> B, and 24, a first pipe 110, and a second pipe 120. The membrane separation activated sludge treatment apparatus 1 is applied in a configuration including a flow rate adjustment tank 50 in the previous stage of the treatment tank 10.

  The flow rate adjustment tank 50 is a tank that adjusts the flow rate so that the flow rate of the water to be treated introduced into the treatment tank 10 becomes a certain amount or less. In the flow rate adjustment tank 50, sewage originating from domestic wastewater, factory wastewater, factory wastewater, rainwater, or the like is introduced as raw water, and the raw water staying in the flow adjustment tank 50 is processed at a predetermined flow rate by the raw water pump 54a. It is transferred to the tank 10. The flow rate adjusting tank 50 is generally set to a tank capacity capable of quantitatively operating the membrane separation activated sludge treatment apparatus 1 even in sewage treatment in which a large load fluctuation per day is expected.

  FIG. 5 is a diagram showing fluctuations in the amount of treated water and the amount of inflow water in the membrane separation activated sludge treatment apparatus according to Example 1 of the present invention.

In FIG. 5, the vertical axis represents the amount of water (m ³ ), and the horizontal axis represents time (hours). Further, the bold line indicates the amount of raw water introduced into the membrane separation activated sludge treatment apparatus 1 (inflow amount), and the shaded area indicates the amount of treated water to be treated in the treatment tank 10.

  As shown in FIG. 5, the amount of raw water introduced into the membrane separation activated sludge treatment apparatus 1 (inflow water amount) is a time fluctuation of the generation amount of domestic sewage or factory wastewater per day (24 hours), It may fluctuate greatly due to the influence of rainwater inflow due to rainfall. On the other hand, it is preferable that the operation condition of the treatment tank 10 is a quantitative treatment in order to ensure the quality of treated water and reduce the membrane load by keeping the membrane differential pressure in the separation membrane constant. Therefore, in Example 1, the flow rate of the raw water to be introduced is adjusted in the flow rate adjusting tank 50, and the entire amount of the load water is quantitatively processed in the processing tank 10.

In the membrane separation activated sludge treatment apparatus 1, assuming that the load water amount is 400 m ³ / day, for example, the flow rate adjustment tank 50 having a tank capacity of 100 m ³ can adjust the flow rate of the load water amount for 6 hours, and can be roughly leveled. As shown by the shaded area in FIG. 5, the processing tank 10 can perform a quantitative process at 16.7 m ³ / hour. In this way, when the membrane separation activated sludge treatment apparatus 1 is quantitatively operated, the treatment water quality of a certain level or more can be secured even when the treatment time ratio between the aerobic treatment and the anaerobic treatment is fixed. There is an advantage that switching control with oxygen-free treatment can be simplified. In addition, as long as the tank capacity corresponding to the amount of treated water is ensured, the flow rate adjusting tank 50 has a small piping system and the like, so that it is difficult to prevent the processing apparatus from being downsized.

[Example 2]
FIG. 6 is a diagram illustrating an example of a configuration of a combination of a membrane separation activated sludge treatment apparatus and a coagulation separation apparatus according to Embodiment 2 of the present invention.

  As shown in FIG. 6, the second embodiment includes the processing tank 10, membrane separation units 20 </ b> A and 20 </ b> B, aeration means 22 </ b> A, 22 </ b> B, and 24, a first pipe 110, and a second pipe 120. The membrane separation activated sludge treatment apparatus 1 further includes a coagulation separation apparatus 2 installed in parallel to the treatment tank 10, and a configuration in which a flow rate adjustment tank 50 is provided upstream of the treatment tank 10 as in the first embodiment. Has been applied.

  In the flow rate adjustment tank 50, sewage originating from domestic wastewater, factory wastewater, factory wastewater, rainwater, or the like is introduced as raw water, and the raw water staying in the flow adjustment tank 50 is processed at a predetermined flow rate by the raw water pump 54a. While being transferred to the tank 10, it is transferred to the coagulation / separation apparatus 2 at a predetermined flow rate by the distribution pump 54b. That is, in Example 2, in the flow rate adjustment tank 50, raw water as the water to be treated is distributed to the treatment tank 10 and the coagulation separation device 2.

  The aggregating / separating apparatus 2 includes stirring tanks 60, 70, and 80 and a precipitation tank 90. In the aggregating / separating apparatus 2, the aggregating / separating process of impurities in the water to be treated is performed by adding a flocculant and particles having a specific gravity larger than the water to be treated (aggregated core particles). In this aggregating and separating apparatus 2, as the agitation tank, a first agitation tank 60, a second agitation tank 70, and a third agitation tank 80 are provided, which are separated from each other by a bypass wall, The second stirring tank 70 has a structure communicating with the upper side, and the second stirring tank 70 and the third stirring tank 80 have a structure communicating with the lower side. A pipe drawn from above the third stirring tank 80 is connected to the precipitation tank 90.

  The 1st stirring tank 60 is a tank which mixes the floating substance and inorganic flocculant contained in to-be-processed water. The first stirring tank 60 is provided with stirring means 62 for stirring the water to be treated.

  In the first agitation tank 60, an inorganic flocculant such as an aluminum flocculant such as sulfuric acid band (aluminum sulfate) or polyaluminum chloride or an iron flocculant such as iron chloride or iron sulfate is added to the water to be treated. The Then, the floating substance contained in the water to be treated and the added inorganic flocculant are rapidly agitated and mixed by the stirring means 62 to neutralize the surface charge of the floating substance in the inorganic flocculant, and A floc in which the fine particles and the inorganic flocculant are aggregated is formed. Moreover, the process which precipitates and aggregates the phosphorus (phosphoric acid) contained in to-be-processed water as a salt is also performed.

  The second agitation tank 70 and the third agitation tank 80 are tanks for mixing a floc in which fine particles of suspended solids and an inorganic aggregating agent are aggregated, a polymer aggregating agent, and agglomerated core particles. The second agitation tank 70 is provided with an agitation unit 72 and a particle supply unit 74 for agitating the water to be treated. The third stirring tank 80 is provided with stirring means 82 for stirring the water to be treated.

  In the second stirring tank 70, a polymer flocculant such as an anionic polymer flocculant, a cationic polymer flocculant, and an amphoteric polymer flocculant is added to the water to be treated. Examples of the polymer flocculant include organic flocculants such as polyacrylamide, polyacrylic acid ester, alginic acid, chitin / chitosan, and the like. Further, the specific gravity of the water to be treated is larger than that of the water to be treated by the particle supply means 74, and preferably the specific gravity is higher than that of the floc or the like in which suspended solids or fine particles of the suspended solids and the inorganic flocculant are aggregated. Large particles (aggregated core particles) are added. As agglomerated core particles, for example, silica sand having a diameter of about 0.1 mm is used. Then, a relatively light floc obtained by agglomerating fine particles of the suspended substance and the inorganic flocculant, the polymer flocculant, and the agglomerated core particles are mixed by being slowly stirred by the stirring means 72. And in the 3rd stirring tank 80, while growing a light floc more stably and large-sized with a polymer flocculant, a heavier floc is formed by carrying out capture binding of these to an agglomerated core particle. By forming a heavy floc, separation from the water to be treated by sedimentation is promoted.

  The sedimentation tank 90 is a tank that settles and separates flocs formed in the water to be treated. The sedimentation tank 90 is formed with a water collection trough on the upper side. And the piping pulled out from the 3rd stirring tank 80 is connected to the bottom side rather than the water collection trough. A sludge scraping means 92 is installed near the bottom, and a sludge extraction pipe 240 is connected to the center of the bottom. Note that a plurality of inclined plates or inclined tubes may be disposed in layers above the settling tank 90 with a gap therebetween.

  In the settling tank 90, flocs formed in the water to be treated settle to the bottom and are extracted from the sludge extraction pipe 240. The floc extracted from the sludge extraction pipe 240 is returned to the particle supply means 74 and is subjected to a centrifugal separation process in the particle supply means 74. Aggregated core particles contained in the returned floc are collected and reused by a centrifugal separation process, while the remaining excess sludge is discarded. On the other hand, the supernatant of the water to be treated from which the floc has been removed is collected in the water collection trough and drained into the treated water tank 100 through the treated water pipe 260. On the other hand, the treated water subjected to membrane separation in the membrane separation units 20A and 20B of the treatment tank 10 is drained into the treated water tank 100 through the treated water pipe 190 and merged with the treated water subjected to the flocculation separation process in the flocculation separation device 2. To do. The treated water is drained out of the system by the treated water pump 104.

  The flocculating / separating apparatus 2 provided in the second embodiment makes it possible to treat impurities in the water to be treated without depending on the biological reaction treatment by adding a flocculant and particles having a specific gravity larger than that of the water to be treated. . Therefore, high-speed treatment is possible, and the scale of the treatment device is suitable for downsizing, and the water treatment device can perform good treatment regardless of the amount of inflow water and water quality fluctuation.

  FIG. 7 is a diagram showing fluctuations in the amount of treated water and the amount of inflow water in the combination of the membrane separation activated sludge treatment apparatus and the coagulation separation apparatus according to Example 2 of the present invention.

In FIG. 7, the vertical axis represents the amount of water (m ³ ), and the horizontal axis represents time (hours). The thick line indicates the amount of raw water introduced into the membrane separation activated sludge treatment apparatus 1 (inflow water amount), the shaded area indicates the amount of treated water processed in the treatment tank 10, and the shaded area indicates the amount in the flocculation separation apparatus 2. The amount of treated water to be treated is shown.

  As shown in FIG. 7, in the second embodiment, the load water amount is leveled as in the first embodiment by adjusting the flow rate in the flow rate adjusting tank 50. Then, while performing the membrane separation process in the treatment tank 10, a part of the raw water is distributed to the coagulation / separation apparatus 2, so that the peak cut using the coagulation / separation process is performed as shown by the shaded area in FIG. 7. Processing is performed. Such distribution of raw water to the coagulation / separation apparatus 2 can be realized by controlling the operation and stop of the distribution pump 54b or the discharge output. Note that the raw water pump 54a that introduces raw water into the membrane separation activated sludge treatment apparatus 1 usually has a constant flow rate so that the amount of water flowing into the treatment tank 10 is equal to or less than the planned water amount designed for the treatment tank 10. As shown by the shaded area in FIG. 7, the processing tank 10 is quantitatively operated.

  Distribution of the raw water to the treatment tank 10 and the coagulation / separation apparatus 2 can be controlled according to the amount of raw water introduced into the membrane separation activated sludge treatment apparatus 1. The amount of raw water (inflow water amount; L) is continuously measured at a predetermined time interval by a water amount measurement unit (not shown), and a measured value of the inflow water amount is transmitted to a control device or the like. The water amount measuring means is composed of, for example, a water level meter that measures the water level of the flow rate adjusting tank 50 and other water tanks that receive the raw water, a flow meter that measures the flow rate of the raw water introduced into the flow rate adjusting tank 50, and the like. . The control device has a function of controlling the operation and stop of the distribution pump 54b or the discharge output. The control device calculates the control input amount of the distribution pump 54b and outputs a control signal for controlling the discharge output to the distribution pump 54b so that the distribution pump 54b distributes a predetermined amount of raw water to the flocculation separation device 2. Let me control.

In the operation of the membrane separation activated sludge treatment apparatus 1, the target value of the planned water volume (Q) to be treated in the treatment tank 10 is input to the control apparatus. When the raw water is introduced into the membrane separation activated sludge treatment apparatus 1 and the operation is started, the control device determines whether the inflow water amount (L) measured by the water amount measuring means is equal to or less than the planned water amount (Q). Determine whether. The inflow water amount (L) can be determined as a load amount by accumulating measured values for a predetermined time in the control device. That is, for the planned water amount (Q), for example, an arbitrary amount of treated water converted into a load amount per hour or a daily load amount may be set as the target value. In FIG. 7, the treatment capacity of the treatment tank 10 is designed as 300 m ³ / day, and an amount of treated water (12.5 m ³ / hour) smaller than in Example 1 is set as the planned water amount (Q). Is shown.

  When the amount of raw water introduced into the membrane separation activated sludge treatment apparatus 1 (inflow water amount; L) is equal to or less than the planned water amount (Q), the control device stops the distribution pump 54b. That is, all the raw water staying in the flow rate adjustment tank 50 is introduced into the treatment tank 10 without operating the distribution pump 54b. Then, the treated water subjected to the biological reaction treatment and the membrane separation treatment in the treatment tank 10 is drained from the membrane separation activated sludge treatment apparatus 1 to the treatment water tank 100. By performing such treatment, when the variation in the amount of inflow water is within the range not exceeding the treatment capacity of the treatment tank 10, the biological reaction treatment and the membrane separation treatment are performed on the whole raw water in the treatment tank 10. can do.

  On the other hand, the control device operates the distribution pump 54b at a predetermined discharge output when the amount of raw water introduced into the membrane separation activated sludge treatment apparatus 1 (inflow water amount; L) exceeds the planned water amount (Q). That is, a part of the raw water remaining in the flow rate adjusting tank 50 is introduced into the treatment tank 10 by the raw water pump 54a, and the remaining raw water remaining in the flow rate adjusting tank 50 is agglomerated and separated by the distribution pump 54b. 2 is introduced. Then, the treated water subjected to biological reaction treatment and membrane separation treatment in the treatment tank 10 and the treated water subjected to the flocculation separation process in the flocculation separation device 2 are remixed in the treated water tank 100 and then discharged to the outside of the system. Is done. By performing such treatment, when the fluctuation of the inflow water reaches a range exceeding the treatment capacity of the treatment tank 10, a part of the raw water is distributed to the flocculation separation device 2 so that the peak cut treatment is performed. The treated water subjected to the biological reaction treatment and the treated water subjected to the coagulation separation treatment can be re-mixed and then treated as waste water as treated water. Another method is to monitor the water level of the flow rate adjusting tank 50 or the water tank corresponding thereto and directly control the water level of the distribution pump 54b so that the water level is maintained under the operation of the raw water pump 54a. It is also possible to use it. In the normal water level range, the raw water pump 54a for transporting the raw water to the treatment tank 10 is operated, and the distribution pump 54b for distributing the raw water to the coagulation / separation apparatus 2 is also operated when the predetermined water level is reached.

  The distribution of the raw water to the treatment tank 10 and the flocculation / separation apparatus 2 can be further controlled according to the quality of the treated water to be adapted by the biological reaction process and the flocculation / separation process in the membrane separation activated sludge treatment apparatus 1. The treated water quality is continuously monitored during such operation. That is, the treated water of the treatment tank 10 drained through the treated water pipe 190, the treated water of the coagulation / separation apparatus 2 drained through the treated water pipe 260, and the treated water discharged from the treatment tank 10 and the coagulation / separation apparatus 2 respectively. The water quality index is continuously measured for the treated water remixed in the tank 100. Examples of the water quality index include biochemical oxygen demand (BOD), nitrogen component concentration (total nitrogen concentration, ammonia nitrogen concentration, etc.) and the like. Then, the measured value (Vm) of the water quality index in the treated water is obtained by, for example, a BOD measuring unit (not shown), a nitrogen concentration measuring unit, etc. that collects water in the treated water pipe 190, the treated water pipe 260, the treated water tank 100, etc. Measurement is continuously performed at predetermined time intervals, and the measured value is transmitted to a control device or the like.

  A water quality reference value to be adapted by the membrane separation activated sludge treatment apparatus 1 for a predetermined water quality index is input to the control device in advance. The water quality reference value is, for example, a target concentration defined according to laws and regulations or the use of the membrane separation activated sludge treatment apparatus 1, and for example, values such as 15 mg / L or less for BOD and 25 mg / L or less for total nitrogen concentration are set. Is done. And while continuing operation | movement of the membrane separation activated sludge processing apparatus 1, a control apparatus measures the measured value (Vm) of the water quality parameter | index measured by the BOD measuring means, the nitrogen concentration measuring means, etc. below a water quality reference value (Vr). It is determined whether or not. Note that the measured value (Vm) of the water quality index can be determined as a load amount by accumulating a predetermined amount of time in the control device. That is, for the water quality reference value (Vr), for example, a target value per day may be set.

  When the measured value (Vm) of the water quality index in the remixed treated water is equal to or lower than the water quality reference value (Vr) for the water quality index, the control device operates the distribution pump 54b with a predetermined discharge output. That is, a part of the raw water remaining in the flow rate adjusting tank 50 is introduced into the treatment tank 10 by the raw water pump 54a, and the remaining raw water remaining in the flow rate adjusting tank 50 is agglomerated and separated by the distribution pump 54b. 2 is introduced. Then, the treated water subjected to biological reaction treatment and membrane separation treatment in the treatment tank 10 and the treated water subjected to the flocculation separation process in the flocculation separation device 2 are remixed in the treated water tank 100 and then discharged to the outside of the system. Is done. When the organic substance load and nitrogen load are low by performing such treatment, and the treated water quality of the remixed treated water can be ensured, an operation for distributing a part of the raw water to the coagulation separator 2 Can continue. And the processing tank 10 is stably quantified by the peak cut process by the coagulation / separation apparatus 2 while ensuring the quality of the remixed treated water, and the switching control between the aerobic process and the anaerobic process is simplified. It becomes possible to make it.

  On the other hand, when the measured value (Vm) of the water quality index in the remixed treated water exceeds the water quality reference value (Vr) for the water quality index, the control device stops the distribution pump 54b. That is, all the raw water staying in the flow rate adjustment tank 50 is introduced into the treatment tank 10 without operating the distribution pump 54b. Then, the treated water subjected to the biological reaction treatment and the membrane separation treatment in the treatment tank 10 is drained from the membrane separation activated sludge treatment apparatus 1 to the treatment water tank 100. By performing such treatment, when organic matter load and nitrogen load increase and it becomes difficult to secure the treated water quality of the re-mixed treated water, a part of the raw water is distributed to the coagulation separation device 2 Can be stopped. Then, by subjecting all of the raw water to biological reaction treatment in the treatment tank 10, it becomes possible to reduce the biochemical oxygen demand, nitrogen component concentration, etc. of the treated water.

[Example 3]
FIG. 8 is a diagram illustrating an example of a configuration of a combination of a membrane separation activated sludge treatment apparatus and a coagulation separation apparatus according to Embodiment 3 of the present invention.

  As shown in FIG. 8, the third embodiment includes a processing tank 10, membrane separation units 20 </ b> A and 20 </ b> B, aeration means 22 </ b> A, 22 </ b> B, and 24, a first pipe 110, and a second pipe 120. The membrane separation activated sludge treatment apparatus 1 is further provided with a flocculation separation apparatus 2 arranged in parallel with the treatment tank 10, while being applied in a configuration that does not include a flow rate adjustment tank in the previous stage of the treatment tank 10. In the third embodiment, instead of the flow rate adjustment tank, a raw water receiving tank 51 for distributing raw water to the treatment tank 10 and the flocculation separation device 2 is provided in the previous stage of the treatment tank 10.

  The raw water receiving tank 51 does not substantially have a function of adjusting the flow rate, and has a tank capacity smaller than that of the flow rate adjusting tank 50. In the raw water receiving tank 51, sewage originating from domestic wastewater, factory wastewater, factory wastewater, rainwater, etc. is introduced as raw water, and the raw water introduced into the raw water receiving tank 51 is transferred to the treatment tank 10 by the raw water pump 54a. Is done. At this time, the flow rate of the raw water transferred to the treatment tank 10 is managed so as to be performed within the range of the planned water amount (per hour) designed based on the average load water amount or the like, for example. When the inflow water amount increases, the raw water exceeding the planned water amount is transferred to the coagulation / separation device 2 by the distribution pump 54b, and the peak cut processing is performed.

  FIG. 9 is a diagram showing fluctuations in the amount of treated water and the amount of inflow water in the combination of the membrane separation activated sludge treatment apparatus and the coagulation separation apparatus according to Example 3 of the present invention.

In FIG. 9, the vertical axis represents the amount of water (m ³ ), and the horizontal axis represents time (hours). The thick line indicates the amount of raw water introduced into the membrane separation activated sludge treatment apparatus 1 (inflow water amount), the shaded area indicates the amount of treated water processed in the treatment tank 10, and the shaded area indicates the amount in the flocculation separation apparatus 2. The amount of treated water to be treated is shown.

FIG. 9 shows an example in which the treatment capacity of the treatment tank 10 is designed as 300 m ³ / day, and the treated water amount (12.5 m ³ / hour) is set as the planned water amount. As shown in FIG. 9, in Example 3, while the raw water is not adjusted in flow rate, all the inflow water amount is introduced into the treatment tank 10 and processed within the range of the designed water amount or less, while the designed plan. Only when there is an inflow exceeding the amount of water, the remainder exceeding the processing capacity of the processing tank 10 is distributed to the coagulation / separation apparatus 2 for processing. Such processing controls the operation and stop of the raw water pump 54a or the discharge output as well as the control of the distribution of the raw water to the treatment tank 10 and the coagulation / separation apparatus 2 according to the amount of raw water inflow in which the flow rate is not adjusted. It is possible to do so.

  As described above, in the membrane separation activated sludge treatment apparatus 1, when the inflow water amount is lower than the designed planned water amount, the treatment water amount is suppressed by causing the membrane separation units 20A and 20B to operate at low pressure or intermittent operation, and the inflow water amount is the planned water amount. When the ratio exceeds the upper limit, the remaining raw water remaining can be distributed to the flocculation / separation apparatus 2 and subjected to a peak cut process. Even in such an operation, the processing time ratio between the aerobic treatment and the anaerobic treatment can be maintained, and it is not necessary to install a flow rate adjustment tank with a large tank capacity. It becomes possible to reduce the size.

DESCRIPTION OF SYMBOLS 1 Membrane separation activated sludge processing apparatus 2 Coagulation separation apparatus 10 Treatment tank 20A, 20B Membrane separation unit 22A, 22B Aeration pipe (aeration means)
24 Blower (Air diffuser)
32 Air diffuser (aeration means)
34 Blower (aeration means)
40 dissolved oxygen concentration meter 50 flow rate adjusting tank 51 raw water receiving tank 54a raw water pump 54b distribution pump 60 first stirring tank 62 stirring means 70 second stirring tank 72 stirring means 74 particle supply means 80 third stirring tank 82 stirring means 90 sedimentation tank 92 Sludge scraping means 100 Treated water tanks 102A, 102B Air supply pipe (aeration means)
104 treated water pump 110 first pipe 120 second pipe 140 circulating air supply hole 150 exhaust hole 170 air supply pipe (aeration means)
190 treated water piping 240 sludge extraction piping 260 treated water piping V10 first piping valve V20 second piping valve V30 exhaust hole valve

Claims (6)

A single tank membrane separation activated sludge treatment device that performs biological reaction treatment with activated sludge in a single tank,
A treatment tank with an airtight structure that performs biological reaction treatment of treated water using activated sludge,
A membrane separation unit installed in the treatment tank and performing solid-liquid separation treatment between treated water and the activated sludge;
An aeration means installed in the treatment tank, and aerating gas to the treated water and physically washing the membrane separation unit;
A first pipe for supplying outside air to the air diffuser;
A second pipe that circulates and supplies the gas in the gas phase section in the treatment tank to the air diffuser;
A membrane separation activated sludge treatment apparatus, wherein opening and closing of a flow path in the first pipe and switching of a flow path in the second pipe are switched. The membrane separation activated sludge treatment apparatus according to claim 1, further comprising aeration means installed in the treatment tank and aerated with the treated water. The apparatus further comprises a flocculation / separation device installed in parallel to the treatment tank and performing a flocculation / separation process of impurities in the water to be treated by adding a flocculant and particles having a specific gravity larger than that of the water to be treated. The membrane separation activated sludge treatment apparatus according to claim 1 or claim 2. A single tank type membrane separation activated sludge treatment method for performing biological reaction treatment with activated sludge in a single tank,
A treatment tank with an airtight structure that performs biological reaction treatment of treated water using activated sludge,
A membrane separation unit installed in the treatment tank and performing solid-liquid separation treatment between treated water and the activated sludge;
An aeration means installed in the treatment tank, and aerating gas to the treated water and physically washing the membrane separation unit;
A first pipe for supplying outside air to the air diffuser;
In a membrane separation activated sludge treatment apparatus provided with a second pipe that circulates and supplies the gas in the gas phase section in the treatment tank to the air diffusion means,
Opening the flow path in the first pipe and closing the flow path in the second pipe;
Air is supplied to the air diffuser through the first pipe, and the air is diffused into the water to be treated in the treatment tank by the air diffuser, so that the water to be treated is biological under aerobic conditions. An aerobic treatment comprising a reaction treatment step, and
Closing the flow path in the first pipe and opening the flow path in the second pipe;
A gas in a gas phase portion in the treatment tank is supplied to the aeration means through the second pipe, and the gas is diffused into the water to be treated in the treatment tank by the aeration means, and While alternately performing oxygen-free treatment consisting of a process of biological reaction treatment of treated water under oxygen-free conditions,
A membrane separation activated sludge treatment method characterized by performing a biological reaction treatment with the activated sludge of the water to be treated and performing a solid-liquid separation treatment between the treated water of the biological reaction treatment and the activated sludge by the membrane separation unit. . A membrane separation activated sludge treatment method according to claim 4,
In the membrane separation activated sludge treatment apparatus, further comprising aeration means installed in the treatment tank and aerated with the treated water,
Opening the flow path in the first pipe and closing the flow path in the second pipe;
Air is supplied to the air diffuser through the first pipe, the air is diffused into the water to be treated in the treatment tank by the air diffuser, and the water to be treated is aerated by the aeration means. Aerobic treatment comprising a step of subjecting the water to be treated to a biological reaction treatment under aerobic conditions, and
Closing the flow path in the first pipe and opening the flow path in the second pipe;
The gas in the gas phase in the treatment tank is supplied to the aeration means through the second pipe, and the gas is diffused into the water to be treated in the treatment tank by the aeration means, and the aeration While stopping the operation of the means, alternately performing an oxygen-free treatment consisting of a step of biological reaction treatment of the treated water under anoxic conditions,
A membrane separation activated sludge treatment method characterized by performing a biological reaction treatment with the activated sludge of the water to be treated and performing a solid-liquid separation treatment between the treated water of the biological reaction treatment and the activated sludge by the membrane separation unit. . A membrane separation activated sludge treatment method according to claim 4 or 5,
A membrane separation activated sludge treatment apparatus further provided with a coagulation separation apparatus that is installed in parallel with the treatment tank and performs coagulation separation processing of impurities in the water to be treated by adding a flocculant and particles having a specific gravity greater than the water to be treated. In
When the amount of raw water introduced into the membrane separation activated sludge treatment device is less than or equal to the planned amount, all of the raw water is introduced into the treatment tank, and the treated liquid subjected to solid-liquid separation treatment is drained from the membrane separation activated sludge treatment device. And
When the amount of raw water exceeds the planned amount of water, a part of the raw water is introduced into the treatment tank, and the remainder of the raw water is introduced into the coagulation / separation device, and the treated water subjected to the solid-liquid separation treatment and the treatment subjected to the coagulation separation treatment A membrane separation activated sludge treatment method, wherein water is mixed again and drained from the membrane separation activated sludge treatment apparatus.

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