JP6067268B2 - Water treatment system - Google Patents

Description

  In the present invention, even in the case of sewage whose water quantity and water quality fluctuate, the sewage can be processed into a predetermined water quality in a short time, and even when urgent operation of the facility is required, The facility can be transported urgently, for example due to natural disasters or accidents, it will be malfunctioning, and it will not be expected to be restored in a short period of time. It is related with the water treatment system which can be used as.

  When treating sewage, a treatment method that conforms to the design and planning guidelines for sewage treatment facilities will be selected. For example, conventional small-scale sewage treatment methods include a long-term aeration method and standard activated sludge method. The former method is a combination of an oxidation ditch tank (hydraulic residence time (HRT): about 24 hours) and a gravity settling tank (HRT: about 6 hours). A combination of a settling basin (HRT: about 3 hours), an aeration tank (HRT: about 8 hours) and a final settling basin (HRT: about 3 hours).

Here, the hydraulic residence time (unit: hour) abbreviated as HRT is the time from when the treated water flows into each water tank / equipment until it flows out, that is, the water stays in each water tank / equipment. When the amount of treated water Q (unit: m ³ / hour) is the same, the facility scale V (aquarium volume; unit: m ³ ) increases as this time increases. Meaning (HRT = V / Q).

  In the conventional small-scale sewage treatment system as described above, the time required for treatment (total of HRT) is approximately 14 to 30 hours, and the time required to design, construct, and complete a facility of such scale For a long period of months to dozens of months. For this reason, it is not possible to respond immediately when an emergency is required, such as the restoration of a sewage treatment facility that has been malfunctioning due to a natural disaster or accident.

  Also, in conventional small-scale sewage treatment methods, treatment is performed after removing relatively long HRT tanks (large water tanks) such as oxidation ditch tanks and aeration tanks that remove soluble organic components by floating microorganisms and soluble organic components. Since a gravity sedimentation tank and a final sedimentation tank that separate water and microorganisms are used, the scale of the facility is large, and it is difficult to secure a site for the facility.

  Furthermore, when the sewage treatment area is damaged, the inflow and quality of the sewage are expected to change depending on the recovery of the sewer pipe and the recovery status of the treatment area. However, it is usually difficult to predict the occurrence timing of this fluctuation. Sewage treatment facilities are required to have a function that can respond flexibly and promptly to such fluctuations, but it takes a long time for the treatment to stabilize in the conventional small-scale sewage treatment method that mainly uses floating microorganisms. .

  Patent Document 1 discloses a treatment method by physicochemical treatment that does not use microorganisms as a treatment method that can stably perform sewage treatment since the site of the facility is a small area. In this treatment method, the agglomerated water obtained by adding a flocculant to the separated pressure levitation separated water by adding pressurized water to the inflowing sewage and separating it is separated into treated water and concentrated water by membrane filtration, The concentrated water is returned to the coagulation system, and the backwash water obtained by backwashing the membrane is treated again together with the inflowing sewage.

However, the treatment method of Patent Document 1 does not take into account the response to some soluble components that are not separated by pressurized flotation. If this is removed by membrane filtration, the reverse osmosis membrane (RO membrane) A facility capable of filtering at the molecular level is required. It is known to those skilled in the art that when the pressure floating separation water is directly filtered with such a reverse osmosis membrane, the reverse osmosis membrane is immediately clogged and it is difficult to restore the filtration capacity by washing. Is a well-known fact. Usually, in order not to affect the reverse osmosis membrane, other pre-filtering equipment that preliminarily filters the pressurized flotation separated water by rapid filtration or microfilter (MF), ultrafiltration membrane (UF), etc. After that, it is necessary to perform filtration with a reverse osmosis membrane. Installing a multi-stage membrane filtration facility as described above in a treatment facility that requires a processing capacity of at least several hundred m ³ per day and usually several tens of thousands m ³ like sewage increases the scale of the facility. The cost and energy for membrane filtration, cleaning and maintenance are enormous.

JP-A-5-192694

The present inventors have recognized at least the following problems when conceiving the present invention.
(1) For quick recovery of sewage treatment facilities that have become dysfunctional due to natural disasters or accidents, HRT is used for treatment methods that depend on oxidation by microorganisms (activated sludge), such as long-term aeration and standard activated sludge methods. Long and large facilities require a large site area, and it takes time from planning to completion, so a processing facility that requires a small site area and can be completed in a short time is required.
(2) Although the coagulation component can be removed by the treatment method using the coagulation separation method, it cannot cope with the non-aggregation component (soluble organic component), so it can also remove the non-aggregation component (soluble organic component). A processing system in combination with a corresponding processing method is required.
(3) The amount and quality of inflowing sewage changes as the sewage treatment area is restored and reconstructed, so a treatment system that can follow these changes is necessary.

  The present invention has been made in order to solve the above-described problems, and can reliably remove cohesive components and non-cohesive components in sewage, and can perform treatment procedures in response to fluctuations in the amount and quality of sewage. It is an object of the present invention to provide a water treatment system that can be easily changed and can be used as an alternative or supplementary facility for a sewage treatment facility in a stricken area or the like.

  In order to solve the above-described problems, a water treatment system according to the present invention includes a carrier tank provided with a plurality of microbial carriers, a carrier treatment apparatus provided with an air diffuser for diffusing the inside of the carrier tank, and an inorganic flocculant. Inorganic flocculant injection equipment for injecting polymer, polymer flocculant injection equipment for injecting polymer flocculant, mixing stirrer equipped with a stirrer, and introducing agglomerated mixed liquid flowing out of the mixing stirring tank And then separating the coagulated sludge from the coagulation sedimentation treatment apparatus equipped with a sedimentation tank for discharging the supernatant water, the sludge extraction pump for extracting the sedimentation sludge from the sedimentation tank, and the sedimentation sludge extracted by the sludge extraction pump. And a settling promoting material separation and recovery device equipped with a separation and recovery device that collects the settling promoting material and supplies it to the mixing and stirring tank.

  In the water treatment system according to the present invention, the mixing and stirring tank includes a mixing tank for injecting and stirring the inorganic flocculant, and a coagulating tank for injecting the polymer flocculant and supplying and stirring the settling accelerator. It is characterized by this.

  The water treatment system according to the present invention is characterized in that the microbial carrier is composed of a trunk thread having both ends fixed and a plurality of branch threads provided on the trunk thread.

  The water treatment system according to the present invention includes a contaminant removal facility for removing contaminants from the treated water, introduces the treated water into the contaminant removal facility, and supports the treated water from which contaminants have been removed by carrier treatment. The carrier tank effluent introduced into the apparatus and flowing out from the carrier treatment apparatus is introduced into the coagulation sedimentation treatment apparatus.

  The water treatment system according to the present invention is provided with a solid-liquid separation facility that removes suspended solids from the carrier tank effluent flowing out of the carrier treatment device, and introduces water to be treated into the coagulation sedimentation treatment device. The sedimentation tank effluent flowing out from the apparatus is introduced into the carrier treatment apparatus, and the carrier tank effluent flowing out from the carrier treatment apparatus is introduced into the solid-liquid separation facility.

  According to the water treatment system of the present invention, the carrier treatment apparatus is provided with a carrier tank in which a plurality of microbial carriers are arranged and an air diffuser for aeration inside the carrier tank. It becomes easy to hold the aerobic microorganisms that absorb and decompose the microorganisms in the carrier tank under favorable aerobic conditions. In addition, when the amount of microorganisms retained on the microbial carrier is more than necessary for the treatment of the treated water, the turbulent strength of the diffuser adds the flow of water and bubbles in the carrier tank. In addition, the flow of bubbles peels off excess microorganisms on the microorganism carrier, so that a necessary amount of microorganisms can be maintained for treatment of the water to be treated.

  According to the water treatment system of the present invention, the coagulation / sedimentation treatment apparatus is provided with an inorganic coagulant injection facility for injecting an inorganic coagulant, a polymer coagulant injection facility for injecting a polymer coagulant, and a stirrer. A mixing agitation tank in which the material is present and a precipitation tank that introduces the agglomerated mixed liquid flowing out from the mixing agitation tank and separates it into solid and liquid, and discharges the supernatant water. By agglomerating reliably with the flocculant, the polymer flocculant and the sedimentation accelerator are used to form agglomerated sludge with high sedimentation in the agglomerated mixed liquid in the mixing and stirring tank. Clear water can be easily separated as sedimentation tank effluent, and sedimented agglomerated sludge as sedimentation sludge.

  According to the water treatment system of the present invention, the settling promoting material separating and collecting device separates the sludge withdrawing settling sludge in the settling tank, and the aggregated sludge from the settling sludge withdrawn by the sludge drawing pump, and the settling promoting material A separator / collector that collects and supplies the mixture to the mixing and stirring tank through the settling accelerator supply pipe is provided. (Interface between the supernatant water and the precipitated sludge) can be managed to prevent deterioration of the quality of the treated water due to the entrainment of the precipitated sludge at the treated water outlet of the settling tank. In addition, the aggregated sludge separated from the precipitated sludge by the separator / collector is used for the sludge treatment, and the collected sedimentation promoting material is supplied to the mixing and stirring tank through the sedimentation promoting material supply pipe. Are always reused.

  According to the water treatment system according to the present invention, the carrier treatment device, the coagulation sedimentation treatment device, and the sedimentation promoting material separation / recovery device that exhibit the above-described effects are used. Clean treated water can be obtained by adsorption, decomposition, aggregation and separation efficiently with a short residence time.

  According to the water treatment system of the present invention, the mixing and stirring tank is composed of a mixing tank for injecting and stirring the inorganic flocculant and a coagulating tank for injecting the polymer flocculant and supplying and stirring the settling accelerator. Therefore, after the agglomeration treatment of the non-agglomerated component with the inorganic flocculant has been performed reliably, the polymer flocculant and the settling accelerator can form agglomerated sludge with high sedimentation in the agglomerated liquid mixture. Since liquid separation becomes easy, even if the size of the precipitation tank is reduced, high-quality treated water can be obtained from the precipitation tank.

  According to the water treatment system of the present invention, since the microbial carrier is composed of a stem yarn having both ends fixed and a plurality of branch yarns provided on the stem yarn, the amount of microorganisms required for treatment of the water to be treated Can be held at high density and appropriately, and the scale of the facility including the carrier processing apparatus can be made compact. Further, the contact efficiency between the retained microorganism and the soluble component is improved, and the time required for adsorption of the soluble component can be shortened. Further, excess microorganisms can be appropriately peeled off by the movement of the trunk yarn and branch yarn.

  According to the water treatment system of the present invention, a contaminant removal facility for removing contaminants from the water to be treated to the water treatment system is provided, the treated water is introduced into the contaminant removal facility, and the contaminants are removed. Since the treated water is introduced into the carrier treatment device and the carrier tank effluent flowing out from the carrier treatment device is introduced into the coagulation sedimentation treatment device, adsorption / decomposition to microorganisms and coagulation separation are not required Contaminants are excluded from the water to be treated, and the load on the carrier treatment device and the coagulation sedimentation treatment device is reduced. Since the blockage and breakage of the microbial carrier due to contaminants are prevented, the function of the carrier treatment apparatus can be stably maintained.

  According to the water treatment system of the present invention, a solid-liquid separation facility for removing suspended substances from the carrier tank effluent flowing out from the carrier treatment apparatus is provided, and the water to be treated is introduced into the coagulation precipitation apparatus. Since the precipitation tank effluent flowing out is introduced into the carrier treatment apparatus, and the carrier tank effluent flowing out from the carrier treatment apparatus is introduced into the solid-liquid separation facility, floating microorganisms (floating microorganisms) and microorganism carriers The separated microbial membrane (peeled sludge) is separated to obtain clean treated water. The obtained treated water can be discharged out of the water treatment system. In addition, the microbial flocs and flaking sludge in the coagulated sludge separated by the solid-liquid separation facility are configured to return part or all of them to the carrier tank, so that the amount of microorganisms suitable for the processing purpose can be maintained in the carrier tank. Is possible.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic block diagram which shows the whole water treatment system by Embodiment 1 of this invention, and shows a part broken away. It is the schematic block diagram which shows the modification 1 of the water treatment system of Embodiment 1 shown in FIG. It is the schematic block diagram which shows the modification 2 of the water treatment system of Embodiment 1 shown in FIG. FIG. 6 is a top view showing a microbial carrier used in the second modified example of the water treatment system of the first embodiment shown in FIG. 3 and configured to extend the stem yarn in the horizontal direction. is there. It is an arrow line view from the arrow A direction of FIG. 3A, Comprising: It is a schematic block diagram which shows a microorganisms carrier, its support frame, and aeration equipment. It is another modification of the microorganism carrier used for the modification 2 of the water treatment system of Embodiment 1 shown in FIG. 3, Comprising: A branch thread is comprised with several substantially ring-shaped strings centering on a trunk thread. It is a schematic perspective view which shows the microbial carrier which carried out. It is a schematic block diagram which shows the whole water treatment system by Embodiment 2 of this invention, and fracture | ruptures and shows a part. It is the schematic block diagram which shows the modification 1 of the water treatment system of Embodiment 2 shown in FIG. It is the schematic block diagram which shows the modification 2 of the water treatment system of Embodiment 2 shown in FIG. It is a schematic block diagram which shows the whole water treatment system by Embodiment 3 of this invention, and fractures | ruptures and shows a part. It is the schematic block diagram which shows the modification 1 of the water treatment system of Embodiment 3 shown in FIG. 7, and fractures | ruptures and shows it partially. It is the schematic block diagram which shows the modification 2 of the water treatment system of Embodiment 3 shown in FIG. It is a schematic block diagram which shows the whole water treatment system by Embodiment 4 of this invention, and fractures | ruptures and shows a part. It is the schematic block diagram which shows the modification 1 of the water treatment system of Embodiment 4 shown in FIG. 10, and fractures | ruptures and shows it partially. It is the schematic block diagram which shows the modification 2 of the water treatment system of Embodiment 4 shown in FIG. It is a graph which shows the BOD process condition of the water treatment system by Embodiment 2 shown in FIG. It is a graph which shows SS process condition of the water treatment system by Embodiment 4 shown in FIG. (A1), (A2), (B1) and (B2) are the water treatment system according to the third embodiment shown in FIG. 7 and the conventional water treatment when it is assumed that water treatment is performed under the same treatment conditions. It is a comparison figure of the size of the facility scale with the method (oxidation ditch method).

First, the basic configuration of the water treatment system according to the present invention will be described.
The water treatment system according to the present invention is an all-in-one type capable of treating sewage to a predetermined water quality in a short time, and basically includes a carrier treatment device, a coagulation sedimentation treatment device, and a sedimentation promoting material separation and recovery device. In addition, the apparatus further includes a contaminant removal facility and / or a solid-liquid separation facility. In this system, the flow of water in the system can be changed as appropriate by switching the connecting pipes between the devices, facilities, and devices. For example, it is set or changed as appropriate according to various conditions such as the amount and quality of water to be treated (hereinafter referred to as “inflow water” or “treated water”) such as sewage flowing into the water treatment system, or variations thereof. Therefore, depending on the processing procedure, depending on the processing procedure, the equipment or equipment that supplies the water to be treated and the treated water (to the extent that the treatment by the water treatment system is completed and can be discharged into a river, etc. There may be a difference in the apparatus or equipment that discharges the purified water having a predetermined water quality.

Next, the outline | summary is demonstrated about the relationship between the following each embodiment and its modification, and to-be-processed water.
(1) For example, for treated water that does not contain contaminants, contains a relatively large amount of non-aggregating components (soluble organic components), and has a high biological oxygen demand (BOD), the treated water is used as a carrier. The structure (for example, FIGS. 1-6) of the water treatment system which flows out a clean treated water from a coagulation sedimentation processing apparatus after making it flow into a processing apparatus can be employ | adopted suitably.
(2) For example, for water to be treated that contains impurities, contains a relatively large amount of soluble organic components, and has a high BOD, after passing the water to be treated through the contaminant removal equipment, it flows into the carrier treatment device. A configuration of a water treatment system (for example, FIGS. 7 to 9) that allows clean treated water to flow out from the coagulation sedimentation treatment apparatus can be suitably employed.
(3) For example, for water to be treated with a large amount of unaggregated components such as suspended solids (SS), the treated water is allowed to flow into a coagulation sedimentation treatment device, and then subjected to microbial treatment by a carrier treatment device, followed by solid-liquid separation. The structure (for example, FIGS. 10-12) of the water treatment system which flows out the clean treated water from an installation can be employ | adopted suitably.

  The following embodiments and modifications thereof are specific examples of the water treatment system according to the present invention, these are merely examples of the present invention, and the present invention is not limited to the examples, The water treatment system according to the present invention can be configured including various variations other than the above examples.

Embodiment 1 FIG.
FIG. 1 is a schematic configuration diagram showing the entire water treatment system according to Embodiment 1 of the present invention, with a part thereof broken away.
The water treatment system according to the first embodiment treats water to be treated that does not contain contaminants, contains a relatively large amount of non-aggregating components (soluble organic components), and has a high biological oxygen demand (BOD), for example. And includes a carrier treatment device 1, a coagulation sedimentation treatment device 2, and a sedimentation facilitating material separation / recovery device 3, and is fed via a raw water pump (not shown) through a treated water introduction pipe 4. The treated water to be treated is introduced into the carrier treatment device 1, and the carrier tank outflow water obtained from the carrier treatment device 1 is sent to the coagulation sedimentation treatment device 2 through the connecting pipe 5, and treated from the coagulation sedimentation treatment device 2. It is configured to discharge water out of the water treatment system.

  The carrier treatment apparatus 1 accepts water to be treated and is disposed on a carrier tank 12 in which a plurality of microbial carriers 11 are disposed, and on a tank bottom 12a in the carrier tank 12, and the carrier tank 12 It is comprised roughly from the aeration equipment 13 which diffuses the inside and raises the dissolved oxygen concentration in to-be-processed water.

  The microorganism carrier 11 disposed in the carrier tank 12 may be of any shape and material as long as the surface area to which microorganisms adhere is large and the shape allows easy supply of oxygen from the aeration equipment 13. However, it is not limited to these. Such individual microbial carriers 11 are efficiently dissolved in the carrier tank 12 with soluble components (soluble components in the water to be treated, dissolved oxygen supplied by the diffuser, etc.) and bubbles generated by the diffuser 13. It arrange | positions by the predetermined space | interval so that it may maintain in the state which can contact. The microbial carrier 11 is accommodated in, for example, a rectangular plate-like microbial carrier module 11a, and the microbial carrier module 11a is supported by a support frame 11b. The support frame 11b is supported in the carrier tank 12 by a plurality of columns 11c. The tank bottom 12a is erected. Such a microbial carrier module 11a can be easily lifted from the support frame 11b as needed to check the state of microbial adhesion on the microbial carrier 11 and replace with a new one even during operation of the water treatment system. It can be carried out. The microbial carrier module 11a may be arranged in parallel along the flow of water as long as it increases the chance of contact between the microorganism and the soluble component, while not interfering with the flow of water in the carrier tank 12. Or you may arrange | position with an angle with respect to the flow of the water. Furthermore, a plurality of support frames 11b may be provided in the carrier tank 12 so as to be parallel to each other.

  In such a carrier tank 12, aerobic microorganisms grow on the microorganism carrier 11 using the soluble component in the water to be treated and oxygen supplied from the aeration equipment 13, and a microbial film is formed. The formed microbial membrane adsorbs and decomposes unaggregated components and soluble components in the water to be treated, and some of the components become nutrient sources for microorganisms and are used to form new microbial membranes.

  The air diffuser 13 is disposed on the tank bottom 12a in the carrier tank 12, and has an air diffuser 13a having a plurality of openings (not shown), and a blower for supplying air to the air diffuser 13a. (Not shown). The air diffuser 13a is disposed at a position immediately below the microbial carrier 11 in order to always maintain the aerobic condition necessary for the growth of the aerobic microorganisms on the microbial carrier 11. This aeration equipment 13 is used not only for supplying oxygen for growing aerobic microorganisms on the microorganism carrier 11 but also for peeling the microorganism membrane. Surplus microorganisms when the amount of microorganisms retained on the microbial membrane or microbial carrier 11 in which the amount of the soluble component adsorbed in the water to be treated reaches saturation is more than necessary for the microbial treatment of the water to be treated is a blower ( By increasing the amount of air blown from (not shown), an increase in upward flow velocity (air lift effect) and turbulence of water flow (turbulent flow) accompanying the rise of bubbles intensify the flow of water and bubbles in the carrier tank 12. Thus, the amount of microorganisms necessary for the treatment of the water to be treated in the carrier tank 12 can be maintained by being peeled from the microorganism carrier 11 and flowing out from the carrier tank 12. Although part of the separated microorganisms and surplus microorganisms contribute to microbial treatment as floating microorganisms floating in the treated water in the carrier tank 12, the treated water that has not been adsorbed by the microbial membrane in the end. Together with the non-aggregating components and the floating microorganisms formed in the carrier tank 12, it is sent to the coagulation sedimentation treatment device 2 and separated from the sedimentation tank effluent (treated water) as sedimentation sludge. It is separated by the separation / recovery device and discharged out of the system as agglomerated sludge.

  The coagulation / sedimentation treatment apparatus 2 is added to a mixed liquid obtained by adding an inorganic flocculant to the carrier tank outflow water from the carrier tank treatment apparatus 1, thereby adding a polymer flocculant and a settling accelerator to the unmixed liquid. Inorganic flocculant injection equipment 14 for injecting an inorganic flocculant, which accelerates the aggregation of the flocculent component and increases the sedimentation speed of the aggregated sludge by increasing the weight of the aggregated sludge formed thereby, and injects the inorganic flocculant. A polymer flocculant injection facility 15 for injecting the polymer flocculant, a mixing tank 17 for mixing and stirring the carrier tank outflow water, the inorganic flocculant, the polymer flocculant, and the settling accelerator, and the mixing and stirring tank 17 It consists of a precipitation tank 18 that separates the agglomerated mixed liquid flowing out from the precipitation tank outflow water (treated water) and precipitation sludge by gravity sedimentation.

  The mixing and agitation tank 17 has a partition plate 17b having a lower part spaced apart from a horizontally provided tank bottom 17a and an upper part protruding upward from the water surface. It is divided into a rapid stirring tank 19 on the side and an agglomerated sludge forming tank 20 on the downstream side. The rapid stirring tank 19 is provided with a stirring blade 19a that stirs the carrier tank outflow water that has flowed into the rapid stirring tank 19 and a motor 19b that rotationally drives the stirring blade 19a. Further, the stirring strength by the stirring blade 19a is such that the mixing of the carrier tank effluent and the inorganic flocculant and the mixing of the admixture with the polymer flocculant and the settling accelerator are performed rapidly and uniformly. It is determined within the range that does not crush the aggregated sludge. As shown in FIG. 1, the stirring blade 19a is disposed at a position closer to the upstream side in the rapid stirring tank 19 and away from the partition plate 17b. This is because the upstream side in the rapid stirring tank 19 is a mixing region in which the carrier tank outflow water and the inorganic flocculant are uniformly mixed, and the partition plate 17b side in the rapid stirring tank 19 is mixed with the polymer flocculant and settling acceleration. This is because a material is added to form a sedimentation region in which the aggregated sludge is weighted. By dividing the inside of the rapid stirring tank 19 into the mixing area and the sedimentation area in this way, the agglomerated mixed liquid containing the agglomerated sludge can be quickly transferred to the agglomerated sludge forming tank 20 through the lower part of the partition plate 17b. it can.

  The agglomerated sludge forming tank 20 is provided with an agitating blade 20a for agitating the agglomerated mixed liquid in the agglomerated sludge forming tank 20, and a motor 20b for rotating the agitating blade 20a. A partition plate 17c having an upper portion that does not reach the water surface is erected on the tank bottom 17a on the downstream side of the coagulated sludge forming tank 20 (the most downstream side of the mixing and stirring tank 17). The agglomerated mixed liquid is configured to be sent into the precipitation tank 18 over the upper part of the partition plate 17c. The stirring strength by the stirring blade 20a is determined within a range in which an upward flow is formed in the flocculated liquid mixture and the large flocculated sludge contained in the flocculated liquid mixture is not crushed and refined.

The inorganic flocculant injection facility 14 in the first embodiment is a facility for injecting the inorganic flocculant into the rapid stirring tank 19. The inorganic flocculant storage tank 14 a for storing the liquid inorganic flocculant and the inorganic flocculant Inorganic flocculant injection pipe 14b extending from the agent storage tank 14a to the upper upstream side in the rapid stirring tank 19, and the inorganic flocculant from the inorganic flocculant storage tank 14a via the inorganic flocculant injection pipe 14b. An infusion pump 14c for infusion is schematically configured. As the inorganic flocculant, a known inorganic flocculant such as polyaluminum chloride (PAC), polyferric sulfate (polyiron), ferric chloride and the like is appropriately selected according to the quality of the water to be treated. Can do. If the carrier tank effluent contains a large amount of phosphorus (eutrophication substance), for example, the use of polyferric sulfate (polyiron) can be used to efficiently remove phosphorus so that phosphorus does not remain in the treated water. It is valid. Moreover, the injection amount (chemical injection rate) of the inorganic flocculant for 1 liter of water to be treated is, for example, 5 to 10 mg / L (converted value when calculated as Al ₂ O ₃ ) in the case of polyaluminum chloride (PAC). Although it can use suitably by the injection rate width | variety, it is not limited to this.

  The polymer flocculant injection equipment 15 includes a polymer flocculant preparation device 15a for preparing the polymer flocculant in a liquid state, and a polymer flocculant extending from the polymer flocculant preparation device 15a to above the rapid stirring tank 19. An agent injection tube 15b and an injection pump 15c for injecting the liquid polymer flocculant from the polymer flocculant preparation device 15a via the polymer flocculant injection tube 15b are schematically configured. The polymer flocculant preparation device 15a includes a polymer flocculant mixing tank 15d and a polymer flocculant storage tank for storing, for example, powdery or granular polymer flocculant supplied into the polymer flocculant mixing tank 15d. 15e, a water supply pipe 15f for supplying water such as treated water into the polymer flocculant mixing tank 15d, a valve 15g for opening and closing the flow path in the water supply pipe 15f to adjust the amount of water supply, and a polymer flocculant The mixing tank 15d includes a stirring blade 15h that mixes water and the polymer flocculant, and a motor 15i that rotationally drives the stirring blade 15h. As the polymer flocculant, known polymer flocculants such as amphoteric, cationic, anionic, and nonionic can be appropriately selected according to the quality of the water to be treated. For example, in the case of an anionic polymer, the injection amount (chemical injection rate) of the polymer flocculant per 1 liter of water to be treated can be suitably used with an injection rate width of 0.8 to 2.0 mg / L. It is not limited. Various combinations of the inorganic flocculant and the polymer flocculant are possible, but as the inorganic flocculant, for example, polyferric sulfate (polyiron) is injected and fine flocculated sludge is added to the carrier tank effluent. When the amphoteric polymer flocculant is injected after the formation of, the agglomeration further proceeds, and a strong agglomerated sludge can be formed.

  The sedimentation promoting material is for increasing the sedimentation rate of the aggregated sludge by weighting the aggregated sludge. For example, the diameter is in the range of about 100 to about 400 micrometers and the specific gravity is 2.3 to 2. It is preferable that the material is resistant to wear and shock. For example, a material containing a high silicic acid content such as cinnabar is preferable, but it is not limited thereto.

  The sedimentation tank 18 is a substantially cylindrical gravity sedimentation tank having a substantially conical tank bottom portion 18a inclined downward toward the center. A substantially cylindrical sludge pit 18b for collecting the precipitated sludge is provided at the center of the tank bottom 18a. In the sedimentation tank 18, the aggregated sludge scraping machine 21 that scrapes the precipitated sludge (including the aggregated sludge) deposited on the tank bottom 18a into the sludge pit 18b, and a motor that rotationally drives the aggregated sludge scraping machine 21. 22 is provided. The agglomerated sludge scraper 21 has a structure in which the agglomerated sludge is not mixed into the supernatant water in order to stabilize the sludge interface (the interface between the supernatant water and the precipitated sludge) of the precipitated sludge collected in the sludge pit 18b. The rotation speed is determined within a range in which the precipitated sludge can be scraped and the turbulent interface is not disturbed. In addition, a partition plate 18 c is provided in the vicinity of the partition plate 17 c of the mixing and stirring tank 17 in the upper part in the precipitation tank 18. The upper part of the partition plate 18c protrudes upward from the water surface, the lower part is bent with respect to the upper part so as to incline toward the sludge pit 18b, and the lowermost end thereof is the tank bottom part 18a and the coagulated sludge scraper 21. It is away from. In the upper part of the partition plate 18c, one or two or more water collecting tanks 18d are provided for preventing the settling sludge from being rolled up by the water flow generated when the supernatant water flows out of the settling tank 18.

  The sedimentation promoting material separation and recovery device 3 separates the coagulated sludge from the sludge extraction pump 23 that extracts the sedimented sludge in the sludge pit 18b of the sedimentation tank 18, and the sedimented sludge that is extracted by the sludge extraction pump 23, and the sedimentation promoting material. Is collected and supplied to the settling accelerator supply pipe 16, and the separated sludge return pipe 25 is connected to the separation / collector 24 and the sludge pit 18b and provided with the sludge extraction pump 23. It is roughly composed. The separation / recovery unit 24 is provided on the upper part of the settling promoting material supply pipe 16 of the coagulation sedimentation processing device 2 and is settling accelerated with a larger weight than the coagulated sludge in the precipitated sludge by centrifugal force and gravity (weight difference). It is a cyclone separator that separates the sedimentation promoting material and the coagulated sludge by lowering the material into the sedimentation promoting material supply pipe 16.

Next, the operation will be described.
First, the water to be treated supplied from the treated water introduction pipe 4 into the carrier tank 12 of the carrier treatment apparatus 1 is stirred by the air diffused by the air diffuser 13 and is covered by the microorganisms on the microorganism carrier 11 receiving the oxygen supply. Unflocculated components and soluble components in the treated water are adsorbed and removed, and sent to the rapid agitation tank 19 of the mixing and agitation tank 17 of the agglomeration sedimentation processing apparatus 2 through the connecting pipe 5 as carrier tank outflow water.

  Next, in the rapid agitation tank 19, an inorganic flocculant is injected into the carrier tank effluent stirred by the stirring blade 19a to agglomerate the non-agglomerated components, and a settling accelerator is added to the formed fine agglomerated sludge. Then, the polymer flocculant is injected and the polymer flocculant is injected, so that the fine and weighted flocculent sludge can be made stronger and more settled. By using the polymer flocculant, fine agglomerated sludge is adsorbed to the agglomerated sludge which is strong and has high sedimentation properties, so that mixing of the agglomerated sludge into the sedimentation tank effluent after the precipitation separation in the sedimentation tank 18 is reduced. . The flocculated mixed liquid containing the flocculated sludge which is stronger and has a higher sedimentation property is transferred to the flocculated sludge forming tank 20 through the lower part of the partition plate 17b as indicated by an arrow X.

  Next, in the agglomerated sludge forming tank 20, the agglomerated mixed liquid is sufficiently stirred by the stirring blade 20a, and the agglomerated sludge in the agglomerated mixed liquid grows further while being maintained in a stronger and more settled state. To do. Such an agglomerated mixed liquid is transferred into the sedimentation tank 18 over the upper part of the partition plate 17c by the upward flow formed by the stirring blade 20a as indicated by an arrow Y.

  Next, the agglomerated mixed liquid transferred to the settling tank 18 is separated into settling tank outflow water (treated water) and settling sludge. That is, the agglomerated mixed liquid hits the upper part of the partition plate 18c as indicated by an arrow Y, and the flow direction changes downward, and as indicated by the arrow Z, it descends along the lower part of the partition plate 18c. It reaches the lower region of the catchment basin 18d beyond the lowermost end. In the lower region of the catchment basin 18d, the agglomerated component in the agglomerated mixed liquid is gravity settled as agglomerated sludge and settles on the tank bottom 18a. The agglomerated sludge is collected in the sludge pit 18b by the agglomerated sludge scraper 21. To be collected. The agglomerated sludge precipitated in the sludge pit 18 b is extracted by the sludge extraction pump 23 as the precipitated sludge and sent to the separation / recovery device 24 through the precipitated sludge return pipe 25. On the other hand, the agglomerated mixed liquid in the process where the agglomerated components are gradually separated by gravity sedimentation rises in the lower region of the catchment basin 18d. When it rises to the water tank 18d, it becomes clean separated water (supernatant water) that does not contain agglomerated components, and flows out of the water treatment system from the treated water outlet (not shown) through the discharge pipe 6 as settling tank outflow water (treated water). To be discharged. This treated water may be discharged as it is, or cleaning water for each device constituting the water treatment system, water for preparing a polymer flocculant, domestic water, or a reverse osmosis membrane (RO membrane as necessary) ) Etc. and may be used for drinking water.

  Next, in the separation / recovery unit 24, the precipitated sludge is separated into a settling accelerator and agglomerated sludge by centrifugal force and weight (weight difference). That is, the sedimentation promoting material having a large specific gravity falls while rotating, is collected in the sedimentation promoting material supply pipe 16, and is supplied into the rapid stirring tank 19 disposed on the upstream side of the mixing stirring tank 17. Again, it is subjected to settling acceleration by increasing the weight of the coagulated sludge. On the other hand, agglomerated sludge having a smaller specific gravity than the sedimentation promoting material is discharged out of the water treatment system by a sludge pump (not shown).

As described above, according to the first embodiment, the carrier processing apparatus 1 is configured to include the carrier tank 12 in which a plurality of microbial carriers 11 are arranged, and the air diffuser 13 that diffuses the inside of the carrier tank 12. Therefore, the following excellent effects can be achieved.
(1) It becomes easy to hold aerobic microorganisms that absorb and decompose soluble components in the water to be treated in the carrier tank 12 under favorable aerobic conditions.
(2) When the adsorption amount of the soluble component in the water to be treated reaches saturation, or when the amount of microorganisms retained on the microorganism carrier 11 becomes more than necessary for the treatment of the water to be treated, aeration By increasing the aeration intensity of the equipment 13, the water flow and the bubble flow in the carrier tank 12 are made violent, and excess microorganisms on the microorganism carrier 11 are peeled off by this violent water flow and bubble flow. The necessary amount of microorganisms can be maintained.

  According to the first embodiment, the inorganic flocculant injection equipment 14 for injecting the inorganic flocculant into the coagulation sedimentation treatment apparatus 2, the polymer flocculant injection equipment 15 for injecting the polymer flocculant, and the agitator (stirring blade) for mixing and stirring 19a and 20a and motors 19b and 20b) are provided with a mixing agitation tank 17 and a precipitation tank 18 for separating the agglomerated mixed liquid flowing out of the mixing agitation tank 17 into precipitation tank outflow water and precipitation sludge. As a result, the non-aggregating component in the mixing and stirring tank 17 is reliably aggregated by the inorganic flocculant, and the agglomerated sludge having a high sedimentation property is mixed in the aggregating mixed liquid in the mixing and stirring tank 17 by the polymer flocculant and the settling accelerator. By forming the aggregate sludge in the sedimentation tank 18, the supernatant water can be easily separated as the sedimentation tank outflow water, and the sedimented aggregate sludge can be easily separated as the sedimentation sludge.

According to the first embodiment, the settling promoting material separation and recovery device 3 separates the coagulated sludge from the sludge extraction pump 23 for extracting the settling sludge in the settling tank 18 and the settling sludge extracted by the sludge extraction pump 23, thereby promoting the settling. Since the separation / recovery unit 24 is provided to collect the material and supply it to the rapid stirring tank 19 through the settling accelerator supply pipe 16, the following excellent effects can be obtained.
(1) By appropriately extracting the sludge from the sedimentation tank 18, the sludge interface of the sedimentation sludge in the sedimentation tank 18 is managed, and the quality of the treated water deteriorates due to the entrainment of the sludge at the treated water outlet (not shown). Can be prevented.
(2) In addition, the coagulated sludge separated from the precipitated sludge extracted by the sludge extraction pump 23 by the separator / collector 24 is used for the sludge treatment, and the collected settling promoting material is passed through the settling promoting material supply pipe 16. Therefore, the settling accelerator can be reused at all times.

  According to the first embodiment, since the carrier processing device 1, the coagulation sedimentation processing device 2, and the sedimentation facilitating material separation and recovery device 3 that exhibit the effects described above are provided, the soluble components and the non-aggregation properties in the water to be treated are included. Clean treated water can be obtained by efficiently adsorbing, decomposing, agglomerating and separating the components with a short hydraulic residence time (HRT).

  In the first embodiment, the shape and material of the microorganism carrier 11 are not particularly limited. For example, a short cylindrical resin (for example, see FIG. 2) or a string-like one (for example, see FIG. 3). It may be used. In addition, the microbial carrier 11 in the first embodiment and the microbial carrier 11 having the shape and material shown in FIG. 2 are used in, for example, later-described second to fourth embodiments shown in FIGS. 3 to 12 and modifications thereof. Is possible.

  In the first embodiment, a mechanical stirrer in which a propeller (stirring blade) is disposed in water is used for mixing and stirring in the stirring and mixing tank 17. However, addition of an inorganic flocculant or polymer flocculant and sedimentation are used. The stirring device is not limited to a mechanical stirring device as long as the agglomerated sludge formed by the addition of the accelerator is not crushed. For example, an aeration type stirring device by blowing air into the mixing stirring tank 17 May be used.

Modification 1 of Embodiment 1
FIG. 2 is a schematic configuration diagram illustrating a first modification of the water treatment system according to the first embodiment illustrated in FIG. 1, partly broken away, and the same components as those in FIG. Therefore, duplicate explanation is omitted.
In this modified example 1, a short cylindrical resin is used as the microorganism carrier 11 and an inorganic flocculant is injected into the connecting pipe 5 disposed between the carrier treatment device 1 and the coagulation sedimentation treatment device 2. This is different from the water treatment system of the first embodiment shown in FIG. 1 in that it is configured to perform (line injection).

  The microbial carrier 11 made of a short cylindrical resin is covered with a wire mesh or punching metal having a mesh width that does not hinder the flow of air or water in the carrier tank 12 of the carrier treatment apparatus 1 and can hold the microbial carrier 11. It is immersed in the carrier tank 12 in a state of being accommodated in small portions in the broken microorganism carrier module 11a. By making the microorganism carrier 11 into a short cylindrical shape, microorganisms adhere to the inner and outer surfaces of the cylinder, and the amount of microorganisms per unit volume increases. With the microbial carrier 11 having such a shape, the contact efficiency between the non-aggregable component and the soluble component in the water to be treated and the microbial membrane can be improved while the water flow resistance remains small. Moreover, the adhesion amount of the microorganisms to an outer surface can also be increased by making the outer surface of the short cylindrical microorganism carrier 11 into a waveform, for example. Furthermore, since the microorganism carrier module 11a is configured to be individually liftable as in the case of the first embodiment shown in FIG. 1, it is necessary even during operation of the water treatment system. Accordingly, it is possible to confirm the state of adhesion of microorganisms on the microorganism carrier 11 and exchange for a new one.

  The injection (line injection) of the inorganic flocculant into the connecting pipe 5 can cause the carrier tank effluent mixed with the inorganic flocculant to flow into the rapid stirring tank 19 in advance. Compared with Embodiment 1 in which the inorganic flocculant is injected into the inside, the agglomeration reaction with respect to the non-agglomerated components in the carrier tank effluent can be started earlier, and fine agglomerated sludge can be formed. The early start of this agglutination reaction is, for example, polyferric sulfate (polyiron) in order to prevent phosphorus from remaining in the treated water when the treatment water contains a relatively large amount of phosphorus (eutrophication substance). It is advantageous in that phosphorus can be insolubilized early by injecting an inorganic flocculant such as. Further, as shown in FIGS. 15A1 and 15A2, the entire water treatment system can be miniaturized to such an extent that it can be loaded on a truck bed, for example. Since it is small in size, the hydraulic residence time (HRT) in the mixed stirring tank 17 composed of the rapid stirring tank 19 and the coagulated sludge forming tank 20 is also short. Therefore, in consideration of the shortness of the HRT and the length of the reaction time for insolubilization of phosphorus, the above line injection is particularly advantageous in that the start of the reaction for insolubilization of phosphorus can be accelerated.

As described above, according to the first modification of the water treatment system of the first embodiment, in addition to the functions and effects of the first embodiment, the following excellent effects can be achieved.
(1) Since a short cylindrical resin having a large surface area on the inner surface and outer surface is used as the microorganism carrier 11, the amount of microorganisms supported on the microorganism carrier 11 can be increased. It can be performed efficiently and in a short time.
(2) Since the inorganic flocculant is line-injected, the flocculent reaction with respect to unaggregated components in the carrier tank effluent can be started at an early stage before flowing into the rapid stirring tank 19.

Modification 2 of Embodiment 1
FIG. 3 is a schematic configuration diagram showing a modification 2 of the water treatment system according to the first embodiment shown in FIG. 1, with a part thereof broken, and the same components as those in FIG. Therefore, duplicate explanation is omitted.
In this modified example 2, a string-shaped microbial carrier 11 is used, a branch pipe 14d and 14e are provided on the inorganic flocculant injection pipe 14b of the inorganic flocculant injection equipment 14, and It differs from the water treatment system of Embodiment 1 shown in FIG. 1 in that a clarification promoting member 18e is provided in a region below the water collecting tank 18d and above the coagulated sludge scraper 21.

  The string-like microbial carrier 11 constituting the microbial carrier module 11a is provided so as to extend in a lateral direction (a direction intersecting the trunk yarn) supported by the trunk yarn that is fixed at both ends extending in the vertical direction. And a plurality of branch yarns. This branch yarn moves freely and flexibly up and down and left and right with a portion in contact with the trunk yarn as a fulcrum against the stress of fluid such as liquid in the carrier tank 12 or gas supplied from the diffuser 13 (free movement) ) Structure. On the other hand, the air diffuser 13 supplies air to the liquid in the carrier tank 12 and generates an upward flow due to the buoyancy of the air, etc., and is in an aerobic state with respect to the microbial film grown on the string-like microbial carrier 11. The oxygen necessary for maintaining the temperature and oxidizing the dissolved components is supplied. Even if the microbial membrane formed on the surface of the string-like microbial carrier 11 is enlarged, a part of the microbial membrane is peeled off due to upward flow or free movement of branch yarns, and the microbial carrier 11 can be prevented from being blocked.

  The branch pipe 14d of the inorganic flocculant injection pipe 14b is disposed on the upstream side of the carrier tank 12, that is, above the vicinity of the opening (not shown) of the treated water introduction pipe 4, and from the treated water introduction pipe 4 When the water to be treated flows into the carrier tank 12, the inorganic flocculant can be injected into the water to be treated from the branch pipe 14d. Further, the branch pipe 14e is disposed on the downstream side of the carrier tank 12, that is, above the vicinity of the outlet 12b for allowing the carrier tank outflow water to flow out to the coagulation sedimentation treatment device 2, and the carrier tank outflow water passes through the connecting pipe 5. The inorganic flocculant can be injected into the carrier tank effluent before flowing. Even if the inorganic flocculant is injected into the water to be treated in the carrier tank 12, the flocculated sludge formed from the non-aggregating components and the inorganic flocculant in the water to be treated is fine. Even if it adheres to the membrane, even if it adheres, fine agglomerated sludge can be physically removed from the microbial membrane by aeration from the aeration equipment 13, so that the injection of the inorganic aggregating agent is carried out in the carrier tank 12. Has little effect on microbial treatment in

  The clarification accelerating member 18e rises in the sedimentation tank 18, and the flocculated components remaining in the flocculated mixed liquid in the process of gradually separating the flocculated components by gravity sedimentation are captured and settled on the surface to be clarified. It is a member to be made. The members constituting the clarification promoting member 18e can take various forms. For example, parallel plates that are inclined with a certain interval, corrugated plates that are similarly inclined, and similarly inclined, Examples thereof include, but are not limited to, a rectangular sedimentation pipe partitioned by a plurality of water passages, or a plurality of round pipe units that are similarly inclined. For example, when the clarification promoting member 18e is composed of a plurality of units of the rectangular sedimentation tube, the inclined directions of the adjacent units intersect each other. It is arranged as follows. In the sedimentation tank 18 provided with such a fining promotion member 18e, as shown by an arrow Z, the aggregated mixed liquid in the precipitation tank 18 exceeds the lowermost lower end of the partition plate 18c and is located below the fining promotion member 18e. In this region, the agglomerated components in the agglomerated liquid mixture are gradually gravity settled and separated, and the agglomerated liquid mixture in the process of gravitational sedimentation is the angle that constitutes each unit of the fining promotion member 18e. The ascending component rises from the lower opening of the die settling tube toward the catchment basin 18d. During the rise, the agglomerated component is trapped on the inner wall of the square settling tube and the like. To settle toward the tank bottom 18a. As a result, when the agglomerated component contained in the liquid further decreases and rises to the catchment basin 18d, it becomes clean separated water (supernatant water) that does not contain the agglomerated component, and the treated water outlet as precipitation tank outflow water (treated water). It is discharged from the water treatment system through a discharge pipe 6 (not shown) and discharged, for example.

As described above, according to the second modification of the water treatment system of the first embodiment, in addition to the functions and effects of the water treatment system of the first embodiment, the following excellent effects can be achieved.
(1) Since the inorganic flocculant injection pipe 14b of the inorganic flocculant injection equipment 14 has the two branch pipes 14d and 14e, the inorganic flocculant is selected according to the quality of the water to be treated and the effluent of the carrier tank. At least one of the injection pipe 14b and the branch pipes 14d and 14e is selected, or an inorganic flocculant is injected from all of them to efficiently agglomerate the non-agglomerated components and include fine agglomerated sludge Carrier tank effluent can be obtained.
(2) Since the clarification promoting member 18e is provided in the settling tank 18, gravity settling in the settling tank 18 can be promoted, and gravity settling in the settling tank 18 can be efficiently performed in a short time.

According to the second modification of the first embodiment, since the microbial carrier 11 is configured to include a trunk yarn that is fixed at both ends extending in the vertical direction and a plurality of branch yarns provided so as to extend in the lateral direction, The following excellent effects can be achieved.
(1) The amount of microorganisms necessary for the treatment of treated water can be maintained at high density and appropriately, and the facility becomes compact.
(2) The contact efficiency between the retained microorganism and the soluble component is improved, and the time required for adsorption can be shortened.
(3) Excess microorganisms can be appropriately detached by the horizontal movement of the trunk yarn and the vertical movement of the branch yarn.

  In the second modification of the first embodiment, the trunk yarn of the microorganism carrier 11 is configured to extend in the vertical direction, but may be configured to extend in the horizontal direction as shown in FIG. 3A, for example. In this case, as shown in FIGS. 3A and 3B, the trunk yarn is preferably fixed to the trunk yarn fixing frame 11d provided inside the support frame 11b at a predetermined interval along the horizontal direction. In the carrier processing apparatus 1 including the microorganism carrier 11 configured as described above, as shown in FIGS. 3A and 3B, the air distributed from the air supply pipe 13b through the header pipe 13c is scattered from the air diffuser 13a. Since the air that has been vaporized and becomes fine bubbles rises while passing through the microorganism carrier 11, the residence time of the air in the carrier tank 12 becomes longer, and the oxygen dissolution efficiency increases. In addition, although the fine bubbles tend to be joined and coarsened as they rise, the stem yarn of the microorganism carrier 11 is configured to extend in the horizontal direction, thereby increasing the chance of contact between the stem yarn and the bubble. Then, the bubbles that have started to become coarse can be subdivided to maintain fine bubbles having a large specific surface area as a whole (the interface area with water per unit volume of air is large, so that the oxygen dissolution efficiency is high). In FIG. 3A, the four air diffusers 13a are joined to the header pipe 13c as a pair, and the air supply pipe 13b is joined to the header pipe 13c, but this configuration is an example. There is no limitation to this, and any configuration may be used as long as it can diffuse toward the trunk yarn and branch yarn of the microorganism carrier 11 described above.

  Further, in the second modification of the first embodiment, the branch yarn of the microbial carrier 11 is composed of a plurality of strings extending radially around the trunk yarn. However, the present invention is not limited to this, and the branch yarn is shown in FIG. 3C, for example. Thus, it may be composed of a plurality of substantially ring-shaped strings centering on the trunk thread.

Embodiment 2. FIG.
FIG. 4 is a schematic configuration diagram showing the entire water treatment system according to the second embodiment of the present invention, with a part broken away, and the same components as those in FIG. Is omitted.
In the water treatment system according to the second embodiment, the mixing and stirring tank 17 of the coagulation sedimentation treatment apparatus 2 is divided into a rapid stirring tank (mixing tank) 26, an injection stirring tank (coagulation tank) 27, and a coagulation sludge forming tank (coagulation tank) 20. In the point which comprised, it differs from the water treatment system of Embodiment 1 shown in FIG. The second embodiment is common to the second modification of the first embodiment shown in FIG. 3 in that a clarification promoting member 18e is provided in the settling tank 18.

  On the tank bottom 17a of the mixing and stirring tank 17, a partition plate 17d having an upper portion that does not reach the water surface is erected between a rapid stirring tank (mixing tank) 26 and an injection stirring tank (coagulation tank) 27. The injection stirring tank (coagulation tank) 27 and the coagulation sludge formation tank (coagulation tank) 20 are partitioned by a partition plate 17b. In the rapid stirring tank (mixing tank) 26, a stirring blade 26a that stirs the carrier tank outflow water that has flowed into the rapid stirring tank (mixing tank) 26 and a motor 26b that rotationally drives the stirring blade 26a are provided. In addition, an inorganic flocculant injection pipe 14 b is provided above the upstream side in the rapid stirring tank (mixing tank) 26. Further, in the injection stirring tank (coagulation tank) 27, a stirring blade 27a for stirring the mixed liquid flowing into the injection stirring tank (coagulation tank) 27 and a motor 27b for rotationally driving the stirring blade 27a are provided. In addition, a polymer flocculant injection tube 15 b is provided above the downstream side in the injection stirring tank (aggregation tank) 27.

Next, the operation will be described.
First, the water to be treated supplied from the water to be treated introduction pipe 4 into the carrier tank 12 of the carrier treatment apparatus 1 is agitated by the aeration of the aeration equipment 13 and is supplied on the string-like microbial carrier 11 receiving the oxygen supply. The microorganisms adsorb and remove unagglomerated components and soluble components in the water to be treated, and as a carrier tank outflow water, a rapid stirring tank (mixing tank) of the mixing and stirring tank 17 of the coagulation sedimentation treatment apparatus 2 through the connecting pipe 5. 26.

  Next, in the rapid agitation tank (mixing tank) 26, the inorganic flocculant is injected and mixed in the carrier tank effluent stirred by the stirring blade 26a, and the non-aggregated components in the mixed liquid are finely flocculated sludge. Aggregate. As shown by the arrow X1, this mixed liquid is transferred into the injection stirring tank (aggregation tank) 27 through the upper region of the partition plate 17d.

  Next, in the injection agitation tank (aggregation tank) 27, after the settling accelerator is added to the mixed liquid stirred by the agitation blade 27a, the polymer flocculant is injected to make the mixture stronger and more settled. It becomes high agglomerated sludge. The agglomerated mixed liquid containing such agglomerated sludge is transferred to the agglomerated sludge forming tank 20 through the lower part of the partition plate 17b as indicated by an arrow X.

  Next, in the agglomerated sludge formation tank (mixing tank) 20, the agglomerated mixed liquid is sufficiently stirred by the stirring blade 20a, and the agglomerated sludge in the agglomerated mixed liquid is maintained in a stronger and more settled state. , Grow even bigger. Such an agglomerated mixed liquid is transferred into the sedimentation tank 18 over the upper part of the partition plate 17c by the upward flow formed by the stirring blade 20a as indicated by an arrow Y.

  Next, in the settling tank 18, as shown by the arrow Z, the agglomerated mixed liquid hits the upper part of the partition plate 18c to change the flow direction downward, descends along the lower part of the partition plate 18c, and reaches the bottom of the lower part. When reaching the lower region of the clarification promoting member 18e beyond the lower end, the flocculated components in the flocculated liquid mixture are gradually gravity settled and separated in that region, and the flocculated liquid mixture in the gravity settling process is clarified. Ascending component rises from the lower opening of the promoting member 18e toward the catchment basin 18d, and during the rising, the aggregating component is trapped on the inner wall or the like of the square sedimentation tube. To settle toward the tank bottom 18a. Aggregated sludge precipitated on the tank bottom 18a is collected in the sludge pit 18b by the agglomerated sludge scraper 21. The agglomerated sludge precipitated in the sludge pit 18 b is extracted by the sludge extraction pump 23 as the precipitated sludge and sent to the separation / recovery device 24 through the precipitated sludge return pipe 25. On the other hand, in the flocculated liquid mixture in the process of gradually separating the flocculated components by gravity sedimentation, the flocculated components contained in the liquid further decrease due to the sedimentation promoting action by the clarification accelerating member 18e. When it rises to the water collecting tank 18d, it becomes clean separated water (supernatant water) that does not contain agglomerated components, and is treated as a settling tank effluent (treated water) from the treated water outlet (not shown) through the discharge pipe 6. It is discharged out of the system, for example, discharged.

  Next, in the separation / recovery unit 24, the precipitated sludge is separated into a settling accelerator and agglomerated sludge by centrifugal force and weight (weight difference). The separated sedimentation promoting material is collected in the sedimentation promoting material supply pipe 16 and supplied into the injection stirring tank (coagulation tank) 27 of the mixing and stirring tank 17 so as to accelerate sedimentation by increasing the weight of the coagulated sludge. To be served. On the other hand, the separated coagulated sludge is discharged out of the water treatment system by a mud pump (not shown).

As described above, according to the second embodiment, the mixing agitation tank 17 is mixed with the mixing agitation tank (rapid agitation tank 26) for injecting and stirring the inorganic flocculant, and the settling accelerator is injected with the polymer flocculant. Since it is composed of a coagulation tank (injection agitation tank 27, coagulated sludge formation tank 20) to be supplied and stirred,
(1) In the mixing tank (rapid stirring tank 26), non-aggregating components, exfoliated surplus microorganisms and the like are agglomerated by mixing with the inorganic flocculant, and in the coagulating tank (injection stirring tank 27, aggregated sludge forming tank 20). A settling accelerator and a polymer flocculant are injected to form a strong and highly settled coagulated sludge. In other words, the provision of the mixing tank promotes the growth of the coagulated sludge in the coagulation tank and the adsorption of the fine, hard-to-set-up coagulated sludge to the cohesive sludge having a high sedimentation property. can get.
(2) After the agglomeration treatment of the non-agglomerated component with the inorganic flocculant is performed securely, sludge having a high sedimentation property is formed by the polymer flocculant and the sedimentation accelerator, so that the sedimentation tank 18 itself can be downsized. It is possible to obtain high quality treated water from the sedimentation tank 18 while being able to achieve this.

Modification 1 of Embodiment 2
FIG. 5 shows a first modification of the water treatment system according to the second embodiment shown in FIG. 4, and is a schematic configuration diagram showing a part thereof broken. The same components as those in FIG. Therefore, duplicate explanation is omitted.
In the first modification, the inorganic flocculant is injected (line injection) into the connecting pipe 5 disposed between the carrier treatment device 1 and the coagulation sedimentation treatment device 2. It differs from the water treatment system of Embodiment 2 shown. In addition, in the point of the line injection | pouring of an inorganic flocculant, the modification 1 of this Embodiment 2 is common in the modification 1 of the water treatment system of Embodiment 1 shown in FIG.

  The injection (line injection) of the inorganic flocculant into the connecting pipe 5 can cause the carrier tank effluent mixed with the inorganic flocculant to flow into the rapid stirring tank 26 in advance. Compared with the second embodiment in which the inorganic flocculant is injected into the inside, the agglomeration reaction for the non-aggregable components in the carrier tank effluent can be started earlier. As described in the first modification of the first embodiment, this agglutination reaction is started early when phosphorus (eutrophication substance) is relatively contained in the water to be treated, for example, polyferric sulfate ( By injecting an inorganic flocculant such as polyiron) to insolubilize phosphorus early, it is advantageous in that phosphorus can be prevented from remaining in the treated water. Further, the mixing and stirring tank 17 including the three tanks (the rapid stirring tank 26, the injection stirring tank 27, and the coagulated sludge forming tank 20) in the first modification of the second embodiment is the same as the first modification of the first embodiment. In consideration of the short hydraulic retention time (HRT) and the length of reaction time for phosphorus insolubilization, as in the case of the mixing and stirring tank 17 composed of the two tanks (the rapid stirring tank 19 and the coagulated sludge forming tank 20). Then, the above-mentioned line injection is particularly advantageous in that the reaction start of phosphorus insolubilization can be accelerated.

  As described above, according to the first modification of the second embodiment, since the inorganic flocculant is line-injected, the unaggregated component in the carrier tank effluent before flowing into the rapid stirring tank 26 is obtained. The agglutination reaction can be started early.

Modification 2 of Embodiment 2
FIG. 6 is a schematic configuration diagram showing a second modification of the water treatment system according to the second embodiment shown in FIG. 4 and is partially broken away. The same components as those in FIG. Therefore, duplicate explanation is omitted.
This modification 2 corresponds to the case where there are many soluble components in the water to be treated, and usually collects sludge separated from the microorganism carrier 11 (peeled sludge) and suspended microorganisms that flow out of the carrier tank 12. 4 in that the sludge returning means 28 for returning the suspended sludge in the carrier tank 12 to the treated water introduction pipe 4 is provided in the carrier treatment apparatus 1 for reuse in microbial treatment. Different from the water treatment system of form 2.

  The sludge return means 28 is erected on the tank bottom 12 a on the downstream side of the carrier tank 12 and has a porous plate 29 having an upper portion that does not reach the water surface, and an inner wall portion on the downstream side of the porous plate 29 and the carrier tank 12. A settling zone 30 set in the vicinity of the tank bottom 12a, a sludge return pump 31 disposed on the tank bottom 12a in the settling zone 30, and the sludge return pump 31 and the water to be treated. A baffle (baffle plate) having a sludge return pipe 32 for connecting the introduction pipe 4, a lower part provided in the vicinity of the inner wall part on the downstream side of the carrier tank 12, and a lower part separated from the tank bottom part 12 a and an upper part protruding upward from the water surface. 33). The perforated plate 29 has a plurality of through holes and slits for allowing air from the air diffuser 13 to pass through the precipitated sludge so as not to make the sludge precipitated in the precipitation zone 30 anaerobic environment. Yes.

  The sludge return pump 31 has a suction port (not shown) for sucking the precipitated sludge in the sedimentation zone 30, and the suction port (not shown) does not disturb the sludge interface of the precipitated sludge. It is desirable to arrange it under the sludge interface. In the second modification, the sludge return pump 31 is disposed in the carrier tank 18. For example, a suction port (not shown) is provided in the tank bottom 18 a of the carrier tank 18, and the sludge return pump 31 The main body may be disposed outside the carrier tank 18. In the former case (Modification 2), the sludge return pump 31 is disposed in the carrier tank 18 so that the water treatment system can be made compact with respect to the volume corresponding to the volume of the sludge return pump 31 itself. be able to. In the latter case, the maintainability of the sludge return pump 31 can be improved.

  The baffle plate 33 is a case where exfoliated sludge or suspended microorganisms separated from the microorganism carrier 11 are short-circuited without passing through the upper part of the porous plate 29 and pass through the through holes of the porous plate 29 and flow into the precipitation zone 30. This is a member for preventing the exfoliated sludge and suspended microorganisms from flowing out to the coagulation sedimentation treatment apparatus 2 soon before they settle in the sedimentation zone 30. Between such a baffle plate 33 and the perforated plate 29, an inflow region 34 into the sedimentation zone 30 of the carrier tank outflow water is set, and the baffle plate 33 and the inner wall portion on the downstream side of the carrier tank 12 are formed. In the meantime, an outflow region 35 from the precipitation zone 30 of the carrier tank outflow water is set. The lower inner surface of the inner wall portion on the downstream side of the carrier tank 12 has a downward slope so that the lowermost end (inner corner formed by the inner wall portion and the tank bottom portion 12 a) approaches the precipitation zone 30. This is because the sludge and suspended microorganisms remaining in the carrier tank effluent rising up the outflow region 35 are captured on the surface and settled to the precipitation zone 30, and the inner wall is brought close to the precipitation zone 30 for precipitation. This is to narrow the zone 30 to increase the concentration of precipitated sludge and improve the return efficiency of the precipitated sludge. Furthermore, by setting the precipitation zone 30 substantially in the vicinity of the perforated plate 29, through holes, etc. This is to make it easy to receive air supply from the air diffuser 13 through the slag to prevent the settling sludge in the settling zone 30 from decaying.

  In the carrier treatment apparatus 1 in this modified example 2, the water to be treated is subjected to microbial treatment by the microbial carrier 11 and flows as carrier tank outflow water through the upper part of the perforated plate 29 and against the partition plate 31 as indicated by the arrow X2. Changes to a downward direction and descends the inflow region 34 along the baffle plate 33. At this time, exfoliated sludge and suspended microorganisms in the carrier tank outflow water descend as they are in the inflow region 34 and settle on the tank bottom 12 a in the precipitation zone 30. The precipitated sludge is returned to the treated water introduction pipe 4 through the sludge return pipe 32 by the sludge return pump 31. On the other hand, the carrier tank effluent other than the precipitated sludge rises from the lowermost end of the baffle plate 33 in the outflow region 35 and is transferred to the coagulation sedimentation processing device 2 through the connecting pipe 5 as indicated by an arrow X3.

  As described above, according to the modified example 2 of the water treatment system of the second embodiment, the sludge return means 28 is provided in the carrier treatment apparatus 1, so that the precipitated sludge in the precipitation zone 30 is covered by the sludge return pump 31. By returning to the treated water introduction pipe 4 on the treated water inflow side, in addition to the microbial film fixed on the microbial carrier 11, it becomes possible to hold the exfoliated sludge and the like in the carrier tank 12 as floating microorganisms. For this reason, even when there are fluctuations in the amount of inflow water and the quality of the water to be treated, it is possible to easily set the adsorption capacity of the soluble component required for the carrier treatment apparatus 1 by adjusting the retention amount of exfoliated sludge and the like Is possible.

  In the second modification of the water treatment system of the second embodiment, the sludge in the sedimentation zone 30 is returned to the treated water introduction pipe 4 by the sludge return pump 31 via the sludge return pipe 32. The return destination of the sludge is not limited to this. For example, the sludge may be returned to the upstream side in the carrier tank 12.

Embodiment 3 FIG.
FIG. 7 is a schematic configuration diagram showing the entire water treatment system according to Embodiment 3 of the present invention, with a part thereof broken away, and the same components as those in FIG. Is omitted.
The water treatment system according to Embodiment 3 is applied to, for example, the case where treated water containing impurities, containing a relatively large amount of soluble organic components, and having a high BOD is used. It passes through a so-called “rotor mat” screen-type contaminant removal facility 36 that removes contaminants such as paper contained in the water to be treated, and is then introduced into the carrier treatment apparatus 1. This water treatment system is shown in FIG. 1 in that a contaminant removing facility 36 is provided and a porous plate 37 is provided in a rapid stirring tank 19 constituting the mixing and stirring tank 17 of the coagulation sedimentation treatment apparatus 2. Different from the water treatment system of the first embodiment.

  The contaminant removal equipment 36 is disposed in a water channel P such as a side groove where the treated water flows and is inclined at, for example, about 35 °, and passes the treated water from the inside to the outside to capture the contaminants. , A rotary rake 39 that is rotatably arranged in the screen 38 and scrapes the foreign matter captured by the screen 38, and the foreign matter scraped by the rotary rake 39 is obliquely upward. A screw conveyor 40 that conveys the dust, a press unit 41 that pressurizes and dehydrates the contaminants conveyed by the screw conveyor 40, and a contaminant conveyance that discharges the contaminants (debris) depressurized and dehydrated by the press unit 41. The pipe 42 and a drive device 43 that rotationally drives the rotary rake 39 and the screw conveyor 40 are schematically configured. The screen 38 is formed by arranging a plurality of screen bars 38a in a cylindrical shape, and a cleaning device 44 for cleaning the screen 38 and eliminating clogging and the like is provided on the screen 38. . Further, the press unit 41 is provided with a drain 45 for discharging waste water generated by pressure dehydration of impurities. Since the contaminant removal equipment 36 configured in this way can remove contaminants in the water to be treated in advance, when the water to be treated with a large amount of contaminants flows directly into the carrier treatment apparatus 1, the contaminants are removed. Entangled or caught on the microbial carrier 11, making it difficult for upward flow or bubbles to pass between the microbial carrier 11 and free movement, inhibiting the contact between the soluble component and the microbial membrane or inhibiting the removal of excess sludge, etc. Various inconveniences can be solved beforehand.

  The perforated plate 37 is disposed on the downstream side of the inorganic flocculant injection pipe 14b in order to form a dedicated region only for injecting the inorganic flocculant in the rapid stirring tank 19 on the upstream side in the rapid stirring tank 19. ing. The perforated plate 37 has an upper part protruding upward from the water surface, and the perforated plate 37 has a plurality of penetrations for transferring the coagulated sludge in the mixed liquid of the carrier tank outflow water and the inorganic coagulant to the downstream side. Holes and slits are formed. By providing the porous plate 37 having such a configuration in the rapid stirring tank 19, the contact between the carrier tank effluent and the inorganic flocculant can be promoted. In addition, when mixing of the carrier tank effluent and the inorganic flocculant by the stirring blade 19a becomes insufficient by disposing the porous plate 37, the inorganic flocculant injection side of the porous plate 37 (in the rapid stirring tank 19) Aeration stirring may be performed on the upstream side.

As described above, according to the third embodiment, since the contaminant removal facility 36 for removing contaminants contained in the inflow water to the water treatment system is provided, the following excellent effects can be obtained. .
(1) Contaminants that do not require adsorption / decomposition to microorganisms or coagulation / separation are eliminated, and the load on the carrier treatment apparatus 1 and the coagulation / precipitation treatment apparatus 2 is reduced.
(2) Since the microorganism carrier 11 is prevented from being blocked or damaged by foreign substances, the function of the carrier processing apparatus 1 can be stably maintained.

  In the third embodiment, a so-called “rotor mat” screen type is used as the contaminant removal equipment 36, but the present invention is not limited to this, as long as it is a contaminant removal equipment capable of protecting the microorganism carrier 11. A bar screen with a lifting function shown in FIG. 9 may be used. Moreover, in order to remove the contaminants in the to-be-processed water, such contaminant removal equipment also in the embodiment shown in FIGS. 1 to 6 and the embodiment shown in FIGS. May be provided.

Modification 1 of Embodiment 3
FIG. 8 shows a first modification of the water treatment system of the third embodiment shown in FIG. 7 and is a schematic configuration diagram showing a part thereof broken. The same components as those in FIG. Therefore, duplicate explanation is omitted.
In the first modification, the so-called rotary fin (registered trademark) type is used which solid-liquid separates and concentrates the coagulated sludge discharged from the separation / collector 24 of the settling accelerator separation / recovery device 3 and collecting the settling accelerator. And a separation liquid return pipe 47 for returning the separation liquid separated by the solid-liquid separation equipment 46 to the upstream side in the carrier tank 12 of the carrier processing apparatus 1. This is different from the water treatment system of the third embodiment shown in FIG.

  The solid-liquid separation equipment 46 includes a substantially cylindrical water tank 48 having a substantially conical tank bottom part 48a inclined downward toward the center, a cylindrical rotating body 49 rotatably disposed in the water tank 48, A rotating shaft (not shown) which is integrally attached to the central portion of the cylindrical rotating body 49 and extends in the vertical direction, driving means (not shown) for rotationally driving the rotating shaft, and a cylindrical shape It is roughly constituted by a substantially cylindrical center well 50 disposed concentrically at the upper part in the rotating body 49. The cylindrical rotating body 49 is composed of a plurality of substantially strip-shaped separation blades 49a arranged in the vertical direction on the circumference thereof. The horizontal cross-sectional shape of the separation blade 49a is, for example, a “<” shape, and is formed so as to bend a substantially strip-shaped plate body in its length direction. The plurality of separation blades 49a are directed inward with respect to the tangential direction of the circumference serving as the circumferential surface of the cylindrical rotating body 49, and between the bent portion and the adjacent separation blade 49a. The agglomerated sludge is disposed adjacent to each other so as to form a gap (not shown) having an interval enough to discharge only the liquid component (separated liquid) to the outside. On the circumferential surface of the center well 50, a plurality of through-holes 50a for discharging the aggregated sludge to the outer cylindrical rotating body 49 are formed.

  In the solid-liquid separation facility 46 having such a configuration, the coagulated sludge discharged from the separation / recovery device 24 and recovered from the settling accelerator is introduced from above the center well 50, and is formed in a cylindrical shape outside the through hole 50a. It is discharged into the rotating body 49. Due to the rotation of the cylindrical rotating body 49, the coagulated sludge also rotates inside. At that time, only the separated liquid is discharged out of the cylindrical rotating body 49 from the gap (not shown) of the cylindrical rotating body 49, It is returned to the upstream side in the carrier tank 12 by the separated liquid return pipe 47. On the other hand, the coagulated sludge staying in the cylindrical rotating body 49 is gravity settled in the cylindrical rotating body 49, discharged from the outlet (not shown) of the tank bottom 48a in the water tank 48, and sent to the sludge treatment. The coagulated sludge sent to this sludge treatment is concentrated because the liquid component is removed.

  As described above, according to the first modification of the water treatment system of the third embodiment, in addition to the actions and effects of the third embodiment, the water is discharged from the separation / collector 24 and the settling accelerator is collected. Since the solid-liquid separation facility 46 for separating and condensing the aggregated sludge is provided, the volume of the aggregated sludge can be reduced, thereby reducing the scale of the sludge storage / treatment facility (not shown). Alternatively, the operation time can be shortened.

  In the first modification of the water treatment system of the third embodiment, a so-called rotary fin (registered trademark) type is used as the solid-liquid separation facility 46 for concentrating the coagulated sludge discharged from the separation / recovery device 24. As long as the coagulated sludge can be solid-liquid separated and concentrated, other types (for example, the type shown in FIG. 10) can be used. Also in the embodiment shown in FIGS. 1 to 7 and the embodiment shown in FIGS. 9 to 12, in order to concentrate the coagulated sludge discharged from the separation and recovery device 24, the above-described solid A liquid separation facility may be provided.

Modification 2 of Embodiment 3
FIG. 9 is a schematic configuration diagram showing a second modification of the water treatment system according to the third embodiment shown in FIG. 7 and is partially cut away. The same components as those in FIG. Therefore, duplicate explanation is omitted.
In the second modification, a bar screen type foreign matter removal facility 51 with a lifting function for removing foreign matters such as paper contained in the water to be treated flowing into the water treatment system, and a perforated plate are provided. 37, the mixture of the inorganic flocculant and the carrier tank effluent is a rapid stirrer tank that is configured to inject the inorganic flocculant (line injection) into the connecting pipe 5 connected to the quick stirring tank 19 provided upright. 7 is different from the water treatment system of the third embodiment shown in FIG. 7 in that the connecting pipe 5 is connected to the lower side of the wall of the rapid stirring tank 19 so as to flow into the vicinity of the tank bottom 17a in the tank 19.

  The contaminant removal equipment 51 has a bar screen (not shown) disposed in an inclined manner in a water channel P such as a side groove where water to be treated flows, and contaminants captured by the bar screen on the front surface of the bar screen. The rotary rake 52 is lifted up obliquely upward along the rotary rake 52, the driving means 53 for circulatingly driving the rotary rake 52, and the chute 54 for receiving the foreign matter lifted up by the rotary rake 52. Since the contaminant removal equipment 51 configured in this way can remove in advance the contaminants in the water to be treated in the same manner as the above-described contaminant removal equipment 36, the water to be treated with a large amount of contaminants is treated with the carrier. When directly flowing into the apparatus 1, contaminants get entangled or caught on the microbial carrier 11, making it difficult for upward flow or air bubbles to pass between the microbial carriers 11 and free movement, thereby inhibiting contact between the soluble component and the microbial membrane. It is possible to eliminate various inconveniences such as impeding the removal of excess sludge.

  In this modified example 2, by injecting the inorganic flocculant into the connecting pipe 5 (line injection), the agglomeration reaction for the non-aggregable components in the carrier tank effluent can be started at an early stage. The mixed liquid containing fine flocculated sludge formed by the inorganic flocculant flows into the vicinity of the tank bottom portion 17a in the rapid stirring tank 19 so that the flocculation reaction further proceeds in the upstream region of the porous plate 37. The admixture in which the agglomeration reaction has progressed passes through the through-holes of the perforated plate 37 and is gradually transferred to the downstream region of the perforated plate 37. Upon addition, agglomerated sludge that is stronger and more settled is formed.

As described above, according to the second modification of the water treatment system of the third embodiment, the following excellent effects can be obtained in addition to the functions and effects of the third embodiment.
(1) Since the inorganic flocculant is injected (line injection) into the connecting pipe 5 connected to the quick stirring tank 19 in which the porous plate 37 is erected, in the region on the upstream side of the porous plate 37, fine In the region on the downstream side of the perforated plate 37, the polymer flocculant is injected into the mixed liquid containing the fine flocculent sludge and the settling accelerator is added. Agglomerated sludge that is strong and has high sedimentation properties can be formed.
(2) Since the connecting pipe 5 is connected to the lower side of the rapid stirring tank 19 so that the mixed liquid of the inorganic flocculant and the water discharged from the carrier tank flows into the vicinity of the tank bottom 17a in the rapid stirring tank 19, the mixed liquid Is temporarily stored in the lower region on the upstream side of the perforated plate 37, the agglutination reaction can be further advanced in the lower region.

  In the second modification of the third embodiment, a bar screen type with a lifting function is used as the contaminant removal equipment 51, but the present invention is not limited to this as long as the contaminant removal equipment capable of protecting the microorganism carrier 11 is used. For example, the contaminant removal equipment 36 shown in FIGS. 7 and 8 may be used.

  Moreover, in the modification 2 of Embodiment 3, although the connecting pipe 5 was connected to the wall part lower side of the rapid stirring tank 19, the connection position to the rapid stirring tank 19 of this connecting pipe 5 is not restricted to this. For example, the wall part upper side of the rapid stirring tank 19 may be sufficient like the connection pipe 5 shown in FIG.

Embodiment 4 FIG.
FIG. 10 is a schematic configuration diagram showing the entire water treatment system according to Embodiment 4 of the present invention, with a part thereof broken away. The same components as those in FIG. Is omitted.
The water treatment system according to the fourth embodiment is applied to, for example, a case where treated water having a large amount of unaggregated components such as suspended matter (SS) is treated. The carrier treatment apparatus 1 and the coagulation sedimentation treatment apparatus 2 are used. A settling accelerator separation / recovery device 3 and a solid-liquid separation facility 55, water to be treated is introduced into the coagulation sedimentation treatment device 2, and the sedimentation tank effluent obtained from the coagulation sedimentation treatment device 2 is supplied to the carrier treatment device 1. The carrier tank outflow water obtained from the carrier processing apparatus 1 is sent out to the solid-liquid separation facility 55, and the treated water is discharged from the solid-liquid separation facility 55. In this water treatment system, the water to be treated is introduced into the coagulation sedimentation treatment device 2 and the treated water is discharged from the solid-liquid separation facility 55, so that the water treatment system according to the embodiment shown in FIGS. to differ greatly.

  The solid-liquid separation equipment 55 is a filter using a disk filter that removes suspended substances contained in the carrier tank effluent, receives the carrier tank effluent from the upstream end, and extends in the horizontal direction. A rotating drum 56 rotatable around a rotating shaft (not shown), and a plurality of drums extending radially outward from the outer peripheral surface of the rotating drum 56 and arranged at equal intervals in the axial direction A disk filter 57, a part of the disk filter 57 disposed inside, a water tank 58 that receives the filtered water that has passed through the disk filter 57, and each disk filter when it rises above the surface of the filtered water in the water tank 58. A cleaning nozzle 59 that injects cleaning liquid from the axial direction to 57 and a suspended substance that is disposed in the upper part of the rotary drum 56 and removed from the disk filter 57 by the cleaning nozzle 59. It is schematically composed of the water collecting trough 60 for transferring the purification wastewater. Each disk filter 57 is constituted by a segment (not shown) having a substantially fan-shaped cross section that is divided into a plurality of pieces along the circumferential direction, and each segment is a pair of fan-shaped filters (not shown). Has an internal space formed between the two filters by facing each other with a certain gap in the axial direction, and an opening (not shown) communicating with the internal space of the rotary drum 56 is formed in the inner circular arc portion of each segment. Is formed. Such solid-liquid separation by filtration is advantageous in that the mesh width of the filter can be selected in accordance with the target water quality. Note that the water level of the filtered water in the water tank 58 of the solid-liquid separation facility 55 is always measured during operation by a water level meter (not shown), and the disk filter 57 is clogged when the water level rises. Therefore, the cleaning by the cleaning nozzle 59 is started.

Next, the operation will be described.
First, the water to be treated is introduced into the rapid stirring tank (mixing tank) 26 of the coagulation sedimentation treatment apparatus 2. Unflocculated components in the water to be treated are agglomerated by injection of the inorganic flocculant in the rapid stirring tank (mixing tank) 26 to become fine agglomerated sludge. By receiving the injection and the addition of the settling accelerator, the coagulated sludge becomes stronger and more settled, and further grows larger while maintaining the coagulated sludge in the coagulated sludge forming tank 20 in a stronger and more settled state. . In the sedimentation tank 18, the coagulated sludge is settled by gravity sedimentation and separated as sedimentation sludge, and the sedimentation promoting material in the sedimentation sludge is recovered and reused by the sedimentation promoting material separation and recovery device 3. Moreover, the coagulated sludge separated from the precipitated sludge is sent to the sludge treatment.

  On the other hand, the soluble component in the precipitation tank effluent is adsorbed and oxidized by microbial treatment in the carrier tank 12 of the carrier treatment apparatus 1 and sent to the solid-liquid separation facility 55 as the carrier tank effluent.

  Next, the solid-liquid separation equipment 55 obtains clean treated water by solid-liquid separation of suspended microorganisms remaining in the carrier tank outflow water and suspended substances such as exfoliated sludge. That is, the carrier tank outflow water flows into the rotating drum 56 of the solid-liquid separation equipment 55, flows into each segment (not shown) of the disk filter 57 from the opening (not shown), and forms a fan-shaped filter ( It is filtered through (not shown) and is transferred into the water tank 58. Since the suspended water is further removed from the effluent from the carrier tank that has undergone the flocculation process and the microbial process, the filtered water can be directly discharged out of the water treatment system as clean treated water.

  On the other hand, suspended substances in the carrier tank effluent are captured by a fan-like filter (not shown) of the disk filter 57, and when the disk filter 57 rises above the water surface, cleaning wastewater containing suspended substances is opened. It flows down into the water collecting tank 60 from the section (not shown). This washing wastewater is sent to the sludge treatment together with the coagulated sludge separated from the precipitated sludge as described above.

As described above, according to the fourth embodiment, the carrier treatment device 1, the coagulation sedimentation treatment device 2, the sedimentation promoting material separation and recovery device 3, and the solid-liquid separation equipment 55 are provided, and the water to be treated is supplied to the coagulation sedimentation treatment device 2. The sedimentation tank effluent obtained from the coagulation sedimentation treatment apparatus 2 is sent to the carrier treatment apparatus 1, and the carrier tank effluent obtained from the carrier treatment apparatus 1 is delivered to the solid-liquid separation facility 55. Since it constituted so that treated water might be discharged from separation equipment 55, the following outstanding effects can be produced.
(1) For example, to-be-treated water with a lot of unagglomerated components such as suspended solids (SS) is introduced into the coagulation sedimentation treatment device 2 that performs physicochemical treatment to precipitate unaggregated components in turbid components The sedimentation tank runoff water separated as sludge and treated with the carrier treatment apparatus 1 is processed by the carrier treatment apparatus 1, and the suspended microorganisms and the separated sludge (suspended substance) mixed in the carrier tank runoff water are separated by the solid-liquid separation equipment 55. Clean treated water can be obtained.
(2) By first introducing the water to be treated into the coagulation sedimentation treatment device 2, for example, the amount of water to be treated temporarily increases (increase in water load), and the amount of turbid components increases accordingly (water quality load) In the case of an increase in (gap), it is possible to respond immediately (high responsiveness) by changing the aggregation conditions.

  In the fourth embodiment, the coagulated sludge generated in the separation / collector 24 and the cleaning wastewater generated in the solid / liquid separation equipment 55 are sent to the sludge treatment as they are. For example, as shown in FIG. The apparatus may reduce the volume by concentrating the agglomerated sludge and washing wastewater. In this case, it is possible to reduce the scale of the sludge storage / treatment facility (not shown) or shorten the operation time.

  In Embodiment 4, solid-liquid separation equipment by filtration is used, but solid-liquid separation is not limited to filtration, and for example, a solid-liquid separation method by gravity precipitation may be used as shown in FIG.

Modification 1 of Embodiment 4
FIG. 11 shows a first modification of the water treatment system according to the fourth embodiment shown in FIG. 10 and is a schematic configuration diagram partially broken away. The same components as those in FIG. Therefore, duplicate explanation is omitted.
In this modified example 1, for example, a large amount of soluble components are contained in the sedimentation tank effluent, and the target treatment cannot be sufficiently performed only by the amount of microorganisms held on the microorganism carrier of the carrier treatment apparatus 1. Part or all of the suspended microorganisms separated by precipitation and the microbial membrane peeled from the microorganism carrier 11 can be returned to the precipitation tank effluent inflow side of the carrier treatment apparatus 1 to increase the amount of suspended microorganisms in the carrier tank. It is configured as follows. That is, this modification 1 is provided with the solid-liquid separation facility 46 shown in FIG. 8 instead of the solid-liquid separation facility 55 in that the mixing stirring tank 17 is composed of the rapid stirring tank 19 and the coagulated sludge forming tank 20. The sludge discharge pipe 61 is provided in the tank bottom 48a of the water tank 48 of the solid-liquid separation facility 46, branches from the sludge discharge pipe 61 and extends to the connecting pipe 5 on the sedimentation tank effluent inflow side of the carrier treatment apparatus 1. A sludge return pipe 62 is provided, and the sludge return pipe 62 is provided with a sludge return pump 63, which is different from the water treatment system of the fourth embodiment shown in FIG.

Next, the operation will be described.
First, the water to be treated is introduced into the rapid stirring tank 19 of the coagulation sedimentation treatment apparatus 2. Unflocculated components in the water to be treated are agglomerated by the injection of the inorganic flocculant to become fine agglomerated sludge. It becomes. Further, the agglomerated sludge grows larger in the agglomerated sludge forming tank 20 while being maintained in a stronger and more settled state. In the sedimentation tank 18, the coagulated sludge is settled by gravity sedimentation and separated as sedimentation sludge, and the sedimentation promoting material in the sedimentation sludge is recovered and reused by the sedimentation promoting material separation and recovery device 3. Moreover, the coagulated sludge separated from the precipitated sludge is sent to the sludge treatment.

  On the other hand, the soluble component in the precipitation tank effluent is adsorbed and oxidized by microbial treatment in the carrier tank 12 of the carrier treatment apparatus 1 and sent to the solid-liquid separation facility 46 as the carrier tank effluent.

  Next, in the solid-liquid separation facility 46, the carrier tank effluent is introduced from above the center well 50 and discharged from the through hole 50 a into the outer cylindrical rotating body 49. Due to the rotation of the cylindrical rotating body 49, the coagulated sludge in the carrier tank outflow water also rotates inside. At this time, only the separated liquid is removed from the gap (not shown) of the cylindrical rotating body 49. It is discharged to the outside and discharged directly to the outside of the water treatment system as clean treated water.

  On the other hand, the aggregated sludge remaining in the cylindrical rotating body 49 is gravity settled in the cylindrical rotating body 49 and sent to the sludge treatment from the tank bottom 48a in the water tank 48 through the sludge discharge pipe 61 as the precipitated sludge. Here, for example, the sedimentation tank effluent contains a lot of soluble components, and the target treatment cannot be sufficiently performed only by the amount of microorganisms retained on the microorganism carrier 11 in the carrier tank 12 of the carrier treatment apparatus 1. The sediment sludge is returned into the connecting pipe 5 on the inflow side of the sedimentation tank effluent of the carrier treatment apparatus 1 through the sludge return pipe 62 branched from the sludge discharge pipe 61 by operating the sludge return pump 63. Then, it is used for microbial treatment in the carrier tank 12.

As described above, according to the first modification of the fourth embodiment, since the solid-liquid separation facility 46 for removing suspended substances contained in the carrier tank effluent is provided, the following excellent effects can be achieved. Can do.
(1) From the carrier tank effluent, suspended microorganisms and microbial membranes (peeled sludge) separated from the microorganism carrier 11 are separated to obtain clean treated water, which can be discharged out of the water treatment system. .
(2) By configuring a part or all of the microbial floc and exfoliated sludge in the coagulated sludge separated by the solid-liquid separation facility 46 to return to the carrier tank 12, the amount of microorganisms suitable for the processing purpose can be reduced to the carrier tank 12. It becomes possible to hold in.

  In the first modification, the sludge return pipe 62 is connected to the connecting pipe 5, but the sludge may be returned directly to the upstream side of the carrier tank 12 of the carrier processing apparatus 1. .

Modification 2 of Embodiment 4
FIG. 12 is a schematic configuration diagram showing a modification 2 of the water treatment system according to the fourth embodiment shown in FIG. 10, partially broken away, and the same components as those in FIG. Therefore, duplicate explanation is omitted.
In this modified example 2, the coagulated sludge generated in the separator / collector 24 and the washing wastewater generated in the solid / liquid separation facility 55 are concentrated by the solid / liquid separation facility 46 shown in FIG. The liquid is returned to the rapid stirring tank (mixing tank) 26 through the separated liquid return pipe 47 and reused, which is different from the water treatment system of the fourth embodiment shown in FIG.

  According to the second modification of the fourth embodiment, the solid-liquid separation facility 46 for concentrating the coagulated sludge and the washing wastewater is provided, and the separated liquid from the solid-liquid separation facility 46 is rapidly stirred by the separation liquid return pipe 47 ( Since the mixing sludge is returned to the mixing tank 26, the condensed sludge generated in the separator / collector 24 and the washing waste water generated in the solid / liquid separation facility 55 can be concentrated to reduce the volume, and the sludge can be stored. -The processing facility (not shown) can be reduced in scale or operation time.

  In the second modification of the fourth embodiment, a so-called rotary fin (registered trademark) type solid-liquid separation facility 46 is used as the concentrating device. However, other types can be used as long as the condensed sludge and washing wastewater can be concentrated. For example, a concentration device such as a known centrifugal dehydration device may be used.

In the second modification of the fourth embodiment, the separation liquid is returned to the rapid stirring tank (mixing tank) 26, but may be returned to the treated water introduction pipe 4.
In addition, in the water treatment system of Embodiments 1-4 shown in FIGS. 1-12, and these modifications, to-be-processed water, carrier tank effluent, and the inside of each apparatus, apparatus, and / or connection piping etc. A pH detection device (not shown) for detecting the pH of the precipitation tank effluent or the like may be installed. Moreover, you may throw in the pH adjuster for adjusting the pH to to-be-processed water etc. according to the measured value.

Example 1.
FIG. 13 is a graph showing the BOD treatment status when the water treatment system according to the second embodiment shown in FIG. 4 is applied to the treatment of water to be treated having a large component variation of the soluble component. In this graph, the measured value of biological oxygen demand (BOD) is used as an indicator of a soluble component, the BOD concentration (mg / L) is shown on the vertical axis, and the elapsed time (weeks) is shown on the horizontal axis. . Moreover, the rhombus (♦) in the graph indicates the BOD concentration in the treated water, and the square (■) indicates the BOD concentration in the treated water. The BOD concentration in the for-treatment water is shown as a weekly average value, and the BOD concentration in the for-treatment water is shown as the maximum value of the BOD concentration measured in the target week. The BOD concentration in the water to be treated during the implementation period (14 weeks) was 180 mg / L on average.

In Example 1, polyaluminum chloride (PAC) was used as the inorganic flocculant, and the chemical injection rate was 5 mg / L (converted value when calculated as Al ₂ O ₃ ). An anionic polymer was used as the polymer flocculant, and the chemical injection rate was 0.8 mg / L. The chemical injection rate is an injection amount for 1 L of water to be treated. Moreover, the precipitation tank ascending speed was 120 m / hour. The sedimentation tank ascending speed is calculated by dividing the inflow speed (m ³ / hour) into the sedimentation tank 18 by the water area (m ² ) in the sedimentation tank 18. Furthermore, the circulation rate was 6%. This circulation rate is the ratio of the amount of precipitated sludge supplied from the sludge extraction pump 23 to the separator / collector 24 with respect to the amount of water to be treated. In addition, as the sedimentation accelerator, dredged sand having a diameter in the range of about 100 to about 400 micrometers and a specific gravity in the range of 2.3 to 2.8 was used.

  From FIG. 13, the BOD concentration of treated water is always 15 mg / L or less even in the case where the water treatment system according to the second embodiment shown in FIG. I understand that. That is, this water treatment system can always perform a suitable and good water treatment stably for the treated water during the implementation period even if there is a week when the treated water with a high BOD concentration flows. It shows that it was possible.

Example 2
FIG. 14 is a graph showing the SS treatment status when the water treatment system according to the fourth embodiment shown in FIG. 10 is applied to the treatment of water to be treated with large turbidity component fluctuations. In this graph, the measured value of suspended solids (SS) is used as an index of the turbidity component, the SS concentration (mg / L) is shown on the vertical axis, and the elapsed time (weeks) is shown on the horizontal axis. Moreover, the rhombus (♦) in the graph indicates the SS concentration in the treated water, and the square (■) indicates the SS concentration in the treated water. Both SS concentration in to-be-treated water and treated water is shown as a weekly average value. The SS concentration in the water to be treated during the implementation period (14 weeks) averaged 200 mg / L.

  In Example 2, using the same conditions as in Example 1, that is, using the same inorganic flocculant and polymer flocculant, chemical injection rate, and sedimentation accelerator, water treatment was performed so that the same precipitation tank ascending rate and circulation rate were obtained. Went.

  From FIG. 14, the SS concentration of the treated water is always 5 mg / L or less even when the SS concentration in the inflowing water during the implementation period of the water treatment system according to the second embodiment shown in FIG. 10 varies. I understand that. In other words, this water treatment system can always perform a stable and appropriate water treatment for the treated water at all times during the implementation period even if there is a week when treated water with a high SS concentration flows. It shows that it was possible.

Example 3
FIG. 15 shows a large facility scale between the water treatment system according to the third embodiment shown in FIG. 7 and the conventional water treatment method (oxidation ditch method) when water treatment is assumed to be performed under the same treatment conditions. It is a comparison figure, (A1) is a plane of the example of arrangement | positioning of the water treatment system by Embodiment 3, (A2) is a side view of the water treatment system of (A1), (B1) is conventional. It is a top view of the whole facility of a water treatment system, (B2) is a side view of the facility of (B1). Here, as the same treatment condition, an average treatment water amount of 600 m ³ / day and a maximum time treatment amount of 1,200 m ³ / day are assumed.

As shown in FIGS. 15A1 and 15A2, the water treatment system according to Embodiment 3 shown in FIG. 7 has a carrier treatment apparatus 1 in a site area of 45 m ² (width 10 m × depth 4.5 m). In addition, constituent devices such as the coagulation sedimentation processing device 2, the sedimentation promoting material separation and recovery device 3, the contaminant removal equipment 36, and the control panel power equipment can be installed, and the height of the equipment is 3.7 m at the maximum. The components of such a water treatment system are, for example, of a size that can be distributed and loaded on the loading platform of a truck with a loading capacity of 4 tons. Moreover, when water treatment was performed under the same operating conditions as in Example 1, the HRT of the entire water treatment system was 2 hours.

On the other hand, as shown in FIGS. 15 (B1) and (B2), a processing facility using the oxidation ditch method that has been widely used conventionally requires a site area of 361 m ² (width 19 m × depth 19 m), and the height of the facility is also high. It was 5.2 m. Moreover, when the water treatment was performed using the water to be treated having the same BOD concentration (180 mg / L) as the water to be treated used in Example 1, the HRT was 31 hours.

  Comprehensively examining Examples 1 to 3, the water treatment system according to the present invention is equivalent in water treatment capability (BOD treatment capability and SS treatment capability) compared to the conventional oxidation ditch method. However, since the site area is about 1/8 and HRT is about 1/16, it shows that it is a compact water treatment system that can be processed in a short time.

  In the water treatment system shown in FIG. 15 (A1), the contaminant removal equipment 36, the carrier treatment device 1, the coagulation sedimentation treatment device 2, the sedimentation promoting material separation / recovery device 3, and these devices are related. Although the control panel and the power equipment are arranged in a substantially square shape, the layout is not limited to this and is arbitrary, and the water treatment system according to the present invention is not limited to the installation location. Moreover, the inflow place of the to-be-treated water is arbitrary, and when the to-be-treated water flows directly into the carrier treatment apparatus 1 without passing through the contaminant removal facility 36 etc., the first embodiment shown in FIG. In the case where the water to be treated is introduced into the coagulation sedimentation treatment apparatus 2 and the solid-liquid separation equipment 46 or 55 is newly arranged, the amount of influent water and the quality of the influent water are improved. Corresponding to appropriate processing is easy.

  Since the water treatment system according to the present invention includes a carrier treatment device for treating soluble components and a coagulation sedimentation treatment device for aggregating unaggregated components, water other than sewage, for example, groundwater, surface water, and industrial wastewater. Application to processing is also possible.

1 carrier treatment device, 2 coagulation sedimentation treatment device, 3 sedimentation promoting material separation and recovery device,
4 treated water introduction pipe, 5 connection pipe, 6 discharge pipe, 11 microbial carrier,
11a microbial carrier module, 11b support frame, 11c strut,
11d Frame for fixing stem thread, 12 carrier tank, 12a tank bottom, 12b outlet, 13 air diffuser, 13a air diffuser, 13b air supply pipe, 13c header pipe, 14 inorganic flocculant injection equipment, 14a inorganic flocculant reservoir tank,
14b inorganic flocculant injection pipe, 14c injection pump, 14d, 14e branch pipe,
15 polymer flocculant injection equipment, 15a polymer flocculant preparation device,
15b polymer flocculant injection tube, 15c injection pump,
15d polymer flocculant mixing tank, 15e polymer flocculant storage tank,
15f water supply pipe, 15g valve, 15h stirring blade, 15i motor,
16 Settling accelerator supply pipe, 17 Mixing and stirring tank, 17a Tank bottom,
17b, 17c, 17d partition plate, 18 sedimentation tank, 18a tank bottom,
18b Sludge pit, 18c Partition plate, 18d Catchment,
18e clarification promoting member, 19 rapid stirring tank, 19a stirring blade, 19b motor, 20 coagulation sludge formation tank (coagulation tank), 20a stirring blade, 20b motor,
21 agglomerated sludge scraping machine, 22 motor, 23 sludge extraction pump, 24 separator / collector, 25 precipitation sludge return pipe, 26 rapid agitation tank (mixing tank), 26a agitation blade, 26b motor, 27 injection agitation tank (aggregation tank) 27a stirring blade,
27b motor, 28 sludge return means, 29 perforated plate, 30 sedimentation zone,
31 sludge return pump, 32 sludge return pipe, 33 baffle plate, 34 inflow region, 35 outflow region, 36 contaminant removal equipment, 37 perforated plate 37,
38 screens, 39 rotating rakes, 40 screw conveyors,
41 Press part, 42 Contaminant conveyance pipe, 43 Drive device, 44 Cleaning device,
45 drain, 46 solid-liquid separation equipment, 47 separation liquid return pipe, 48 water tank,
48a tank bottom, 49 cylindrical rotating body, 49a separation blade,
50 center well, 50a through hole, 51 contaminant removal equipment,
52 rotating rakes, 53 driving means, 54 chutes, 55 solid-liquid separation equipment,
56 rotating drum, 57 disc filter, 58 water tank, 59 cleaning nozzle,
60 Catchment, 61 Sludge discharge pipe, 62 Sludge return pipe, 63 Sludge return pump,
P water channel, A, X, X1, X2, X3, Y, Z arrow

Claims (5)

A carrier tank provided with a plurality of microbial carriers, and a carrier treatment device provided with an air diffuser for diffusing the inside of the carrier tank;
Inorganic flocculant injection equipment for injecting inorganic flocculant,
Polymer flocculant injection equipment for injecting polymer flocculant,
A mixing and stirring tank provided with a stirrer, and a settling tank having a settling tank in which a settling accelerator is present, and a settling tank that introduces a coagulated liquid mixture flowing out of the mixing and stirring tank, separates it into solid and liquid, and discharges supernatant water ,
A sedimentation pump comprising a sludge extraction pump for extracting the sedimentation sludge from the settling tank, and a separation / collector for separating the agglomerated sludge from the sedimentation sludge extracted by the sludge extraction pump, recovering the settling promoting material, and supplying the settling accelerator to the mixing and stirring tank A water treatment system comprising a promoter separation and recovery device,
It further comprises a solid-liquid separation facility for removing suspended substances from the carrier tank effluent flowing out of the carrier treatment device,
The water treatment system comprises:
Water to be treated whose non-aggregating component is biological oxygen demand concentration at an average of 180 mg / L or more during the introduction period is introduced into the carrier treatment device, and the carrier tank effluent flowing out from the carrier treatment device is flocculated. Introduced into the sedimentation processing equipment,
Water to be treated having an unaggregated component concentration of suspended solids of 200 mg / L or more on average during the introduction period is introduced into the coagulation sedimentation treatment device, and the precipitation tank effluent flowing out from the coagulation sedimentation treatment device is treated as the carrier treatment device. So that the carrier tank effluent flowing out from the carrier treatment apparatus is introduced into the solid-liquid separation facility,
A water treatment system configured to be able to change a flow path of water to be treated. The mixing tank is
A mixing tank for injecting and stirring the inorganic flocculant;
2. The water treatment system according to claim 1, comprising a coagulation tank that injects the polymer flocculant and supplies and agitate the settling accelerator. 3. The microbial carrier is
3. The water treatment system according to claim 1, wherein the water treatment system comprises a trunk yarn having both ends fixed and a plurality of branch yarns provided on the trunk yarn. Before providing a contaminant removal facility for removing contaminants from the treated water, introducing the treated water into the contaminant removal facility, and introducing the contaminants in the treated water into the carrier treatment device by the contaminant removal facility The water treatment system according to any one of claims 1 to 3, wherein the water treatment system is removed in advance . A method for operating a water treatment system according to any one of claims 1 to 4,
Water to be treated whose non-aggregating component is biological oxygen demand concentration at an average of 180 mg / L or more during the introduction period is introduced into the carrier treatment device, and the carrier tank effluent flowing out from the carrier treatment device is flocculated. A process to be introduced into the precipitation treatment apparatus,
Water to be treated having an unaggregated component concentration of suspended solids of 200 mg / L or more on average during the introduction period is introduced into the coagulation sedimentation treatment device, and the precipitation tank effluent flowing out from the coagulation sedimentation treatment device is treated as the carrier treatment device. Introducing the carrier tank effluent flowing out from the carrier treatment apparatus into the solid-liquid separation facility,
A method for operating a water treatment system, comprising:

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