JP4378144B2 - Wastewater treatment equipment - Google Patents

Description

  The present invention relates to a wastewater treatment apparatus that performs treatment of water to be treated, and particularly relates to a construction technique of a wastewater treatment apparatus having a configuration for performing filtration treatment of water to be treated.

2. Description of the Related Art Conventionally, a wastewater treatment apparatus that performs treatment of wastewater discharged from ordinary households, industrial wastewater, or the like has been known to perform a treatment treatment of water to be treated using a carrier (for example, Patent Document 1). reference.).
The waste water treatment apparatus disclosed in Patent Document 1 is a carrier fluid tank that fluidizes a carrier to which aerobic microorganisms adhere to purify treated water, and a treated water using the carrier downstream of the carrier fluid tank. The carrier filtration tank which filters the sludge of this is provided. In the carrier filtration tank, by supplying air to the carrier filtered sludge during normal operation, the carrier is washed back, and the sludge settled and deposited on the bottom of the tank is transferred (extracted) out of the tank. Processing is performed.
By the way, in the support | carrier filtration tank which filters the to-be-processed water as mentioned above, there exists a request | requirement of aiming at further rationalization of process efficiency regarding the backwash process of the said support | carrier filtration tank and sludge transfer processing.
JP 2003-10871 A

  This invention is made | formed in view of this point, and makes it a subject to provide the rational construction technique of the waste water treatment equipment which has the structure which performs the filtration process of to-be-processed water.

  The present invention is configured to solve the above problems. The present invention is particularly configured so that the operation interval of the deposit discharge operation for discharging the deposit deposited below the filtration processing unit is less than the operation interval of the cleaning operation for performing the cleaning process of the filtration processing unit, This is a technology that can realize a rational construction technology for wastewater treatment equipment.

(First invention of the present invention)
A first aspect of the present invention is a wastewater treatment apparatus as described in claim 1.
The waste water treatment apparatus according to claim 1 includes at least a filtration processing unit, a cleaning fluid supply unit, and a deposit discharge unit.
A filtration process part is an area | region filled with the filter medium which filters the to-be-processed water. The “filter medium” as used in the present specification is intended to widely include members capable of filtering solid matter (SS) such as sludge contained in the water to be treated. This is a typical example of “filter medium”. In addition, a filter medium constituted by a regular packing other than the granular carrier is also included in the category of “filter medium” in the present invention. In addition, the filter medium may be filled in the filtration processing section so as to be flowable, or may be filled in the filtration processing section so as not to flow. When the water to be treated containing the material to be filtered such as the solid material (SS) flows through the filtration processing unit, the material to be filtered is filtered by the filter medium.
The cleaning fluid supply means is a means having a function capable of supplying a cleaning fluid to the filtration processing unit. As the “cleaning fluid” as used in the present specification, various fluids that can provide a gas flow or water flow suitable for cleaning to the filtration processing unit, such as gas and water including air, are used. it can. Therefore, it is preferable that the cleaning fluid supply unit is configured to discharge the pressurized cleaning fluid toward the filtration processing unit. By operating the cleaning fluid supply means, the cleaning fluid is supplied to the filtration processing unit.
The deposit discharging means is a means having a function capable of discharging the deposit deposited below the filtration processing unit. Typically, the deposit discharging means of the present invention is configured by an apparatus having a suction function for deposits, such as a pump called a so-called “air lift pump”. By operating the deposit discharging means, the deposit deposited below the filtration processing unit is discharged from the deposition area to the outside of the area.

In this invention, the to-be-processed water is filtered by the to-be-processed water flowing toward the upper part from the lower part to the upper part at the time of filtration operation. That is, the upward flow of the water to be treated acts on the filtration treatment unit during the filtration treatment operation.
Moreover, in this invention, the filtration process part used for the filtration process of to-be-processed water is wash-processed by operating an air supply means at the time of washing | cleaning operation. That is, an object to be filtered that has been filtered and captured by the filter medium in the filtration processing section during the filtration operation is peeled off from the filter medium by the air flow during the cleaning operation, whereby the filter medium is washed (so-called backwashing process). Become.
Further, in the present invention, during the deposit discharging operation, the deposit discharging means is operated to discharge sediment deposited and deposited below the filtration processing unit. That is, the deposit that includes the object to be filtered separated from the filter medium by the cleaning operation and settles and deposits below the filtration processing unit is discharged from the deposition region to the outside of the region during the deposit discharging operation.
In particular, the present invention is configured such that the operation interval of the deposit discharge operation is less than the operation interval of the cleaning operation. This aspect means that, for example, the number of operations of deposit discharge operation per day exceeds the number of operations of cleaning operation per day.

In the configuration in which the water to be treated flows from the lower part to the upper part as in the present invention, the matter to be filtered that has been filtered by the filter medium is particularly lower in the vertical direction of the filter medium in each part of the filter process part. It is easy to be trapped by the filter medium, and the trapped material to be filtered tends to settle down as it is below the filtration processing section. Therefore, for example, even if the deposit discharge operation is not performed in accordance with the cleaning operation, it is effective to enhance the deposit discharging effect by performing the deposit discharge operation more frequently than the cleaning operation as in the present invention. is there. In contrast, when the sediment discharge operation is performed in conjunction with the cleaning operation, or when the number of cleaning operations is increased more than the number of sediment discharge operations, the time required for the water quality to stabilize immediately after the cleaning operation. As a result, the cleaning operation is performed excessively more than necessary.
Moreover, in this invention, it can set so that the frequency | count of the deposit | emission discharge | emission driving | operation per day may be divided into several times, for example. According to such setting, the amount of water discharged together with the deposit can be suppressed as compared with the case where the deposit discharging operation is performed about once a day. As a result, it is possible to prevent a waste deposit discharging operation for unnecessarily extracting water other than the deposit.
Moreover, the energy-saving effect regarding a cleaning operation increases by suppressing the frequency | count of a cleaning operation compared with the deposit discharge operation like this invention.

  In the present invention, the operation interval between the deposit discharge operation and the cleaning operation, for example, the number of operations per day can be set as appropriate. For example, under the condition that the operation interval of the sediment discharge operation is less than the operation interval of the cleaning operation, the operation intervals of the sediment discharge operation and the cleaning operation are appropriately set, or the number of times of the sediment discharge operation per day is 1 day. The number of operations for deposit discharge operation and cleaning operation can be set as appropriate under the condition that the number of cleaning operations per operation is exceeded. In addition, the operation interval between the sediment discharge operation and the cleaning operation does not need to be constant every time, and may be different every time or every predetermined time, or may be set to be different depending on the operation condition, season, etc. May be.

(Second invention of the present invention)
A second invention of the present invention is the waste water treatment apparatus as described in claim 2.
A wastewater treatment apparatus according to a second aspect of the present invention includes the deposit storage area in which the deposit discharged via the deposit discharge means is stored in the configuration according to the first aspect. And the water solid-liquid separated in this deposit storage area | region is discharged | emitted out of the said deposit storage area | region.
In the present invention, for example, the setting to divide the number of times of deposit discharge operation per day into a plurality of times is larger than the case where a large amount of water is transferred to the deposit storage area at once with the deposit. This is effective for improving the solid-liquid separation performance of sediment and water in the storage area. That is, if a large amount of water is transferred to the sediment storage area at once with the sediment, the flow rate of water discharged outside the sediment storage area increases, and the possibility of sludge mixing into the water increases. The solid-liquid separation performance in the storage area is reduced. On the other hand, as in the present invention, the number of times of deposit discharge operation per day is divided into a plurality of times, and the amount of water transferred to the deposit storage area at a time is reduced, thereby moving the deposit storage area outside. An increase in the flow rate of the discharged water can be suppressed, and the solid-liquid separation performance in the deposit storage region can be improved.

(Third invention of the present invention)
A third invention of the present invention is the waste water treatment apparatus as described in claim 3.
The waste water treatment apparatus according to claim 3 is the configuration according to claim 1 or 2, wherein a floating granular carrier is used as a filter medium filled in the filtration processing unit. The “floating granular carrier” referred to in the present specification widely includes granular carriers of various shapes whose apparent specific gravity is smaller than that of water.
According to such a configuration of the wastewater treatment apparatus of the present invention, compared to the case where a sedimentary carrier having an apparent specific gravity larger than that of water is used, the fluidity of the carrier during the washing operation is good, and the carrier is washed. It is effective for improving efficiency. In other words, when a sedimentary carrier is used, the carrier may be partially retained in the filtration treatment part and difficult to fluidize, but the floating granular carrier will flow smoothly through the filtration treatment part and wash the carrier. Efficiency is improved. Accordingly, the frequency of the cleaning operation itself can be suppressed as the carrier cleaning efficiency is improved, and it is reliably prevented that the time required for the water quality to stabilize immediately after the cleaning operation is increased. As described above, the configuration using the floating granular carrier as the filter medium is effective in preventing the washing operation from being performed excessively more than necessary.

(Fourth invention of the present invention)
A fourth aspect of the present invention is a wastewater treatment apparatus as set forth in the fourth aspect.
According to a fourth aspect of the present invention, there is provided the waste water treatment apparatus according to any one of the first to third aspects, wherein the cleaning fluid supply means supplies air as a cleaning fluid to the filtration processing unit from below the filtration processing unit. It can be supplied. Typically, the cleaning fluid supply means of the present invention is configured by an apparatus configured to be able to supply air supplied from a blower or the like from below the filtration processing unit. By operating the cleaning fluid supply means, air is supplied to the filtration processing unit from below the filtration processing unit.
According to the configuration of the wastewater treatment apparatus described in the present invention, for example, compared with the case where water is used as the cleaning fluid, the cleaning effect by bubbling of the air itself is synergized with the cleaning effect by the water flow formed by the air. That is, the effect of cleaning the filter medium in the filtration processing section is enhanced.

  As described above, according to the present invention, in particular, the operation interval of the sediment discharge operation for discharging the deposit deposited below the filtration processing unit is set to be longer than the operation interval of the cleaning operation for performing the cleaning process of the filtration processing unit. By shortening the configuration, it becomes possible to efficiently perform the sediment discharge processing and the cleaning processing of the filtration processing section. Realistic construction technology can be realized.

  Below, the structure etc. of the waste water treatment tank 100 which is one Embodiment of the "drainage processing apparatus" in this invention are demonstrated based on drawing.

FIG. 1 shows a processing flow of a wastewater treatment tank 100 according to an embodiment of the present invention, and FIG. 2 shows an internal configuration of a treatment tank main body 101 of the wastewater treatment tank 100.
As shown in FIGS. 1 and 2, the waste water treatment tank 100 of the present embodiment includes a treatment tank body 101, an aeration screen 110, a flow rate adjustment tank 120, a measurement adjustment device 130, a contaminant removal tank 140, a carrier. A fluid tank 150, a carrier filtration tank 160, a disinfection tank 170, a discharge pump tank 180, a defoaming tank 190, a sludge concentration storage tank 200, and the like are mounted.
As shown in FIG. 1, sewage (treated water) flowing into the wastewater treatment tank 100 is treated by the above-described components, and the treated water is discharged from the downstream of the discharge pump tank 180 to the outside of the wastewater treatment tank 100. On the other hand, the sludge separated and removed in the process of the contaminant removal tank 140 and the carrier filtration tank 160 is once stored in the sludge concentration storage tank 200 and then transported out of the waste water treatment tank 100. Yes. In the present embodiment, sewage (treated wastewater) to be treated in each tank and water flowing in the treatment process for treating the sewage are referred to as “treated water” or “water”.

  As shown in FIG. 2, the aeration type screen 110 has screens of a predetermined size, and removes coarse solids or sand contained in the water to be treated that has flowed into the treatment tank body 101 through the inlet 102. Has the function of removing. In addition, although not particularly shown, air for preventing clogging of the screen is supplied to the aeration type screen 110. The water that has passed through the aeration screen 110 is transferred to the flow rate adjustment tank 120.

The flow rate adjustment tank 120 is a tank having a function as a reservoir tank for temporarily storing water to be treated. The flow rate adjustment tank 120 is provided with a metering pump 122 and a stirring device 124.
The metering pump 122 is a flow rate adjusting pump having a function of transferring water to be treated at a predetermined flow rate per unit time from the flow rate adjusting tank 120 to the metering device 130. For example, the metering pump 122 is configured as a so-called “submersible pump” that is set to be submerged in the water to be treated in the flow rate adjusting tank 120. Note that the metering pump 122 may be configured by an air lift pump instead of the submersible pump.
The stirring device 124 is a device having a function of stirring water in the flow rate adjusting tank 120. As the stirring device 124, typically, a means for stirring water by an air flow of supply air can be used.
Water in the flow rate adjusting tank 120 is transferred to the metering adjustment device 130 via the metering pump 122.
The air used in the agitation device 124, the sludge extraction means 144, the air diffuser 154, the backwash device 164, the return means 168, the sludge extraction means 169, and the agitation device 204, which will be described later, is not particularly shown. It is supplied from the blower that supplies air.

The metering adjustment device 130 can return a part of the water to be treated to the flow rate adjustment tank 120, so that the flow rate of the water to be treated transferred to the contaminant removal tank 140 becomes constant as appropriate. Has the function of adjusting the flow rate (measuring). That is, the metering pump 122 and the metering adjustment device 130 prevent the excessive supply state of the water to be treated by adjusting the flow rate of the water to be treated that is supplied to each treatment tank after the contaminant removal tank 140. To fulfill.
The water weighed by the metering device 130 is transferred to the contaminant removal tank 140.

The contaminant removal tank 140 is a tank that performs processing for separating solid components contained in the water to be treated from the water to be treated as impurities, and fulfills a solid-liquid separation function of the water to be treated. In this contaminant removal tank 140, an advection pipe 142 and a sludge extraction means 144 are installed.
The advection tube 142 includes a first extending portion 142a extending in the vertical direction and a second extending portion 142b extending in the horizontal direction from the first extending portion 142a. The first extending portion 142a has a lower end (inlet portion) disposed at a lower position than the water surface in the contaminant removal tank 140, and scum or the like staying near the horizontal flows out to the carrier flow tank 150. It is the composition which prevents. The second extending portion 142b is provided with a slit-shaped carrier separation device (not shown) on the downstream side thereof, and a granular carrier C1 of the carrier fluidized tank 150 described later flows into the contaminant removal tank 140 side. It is the composition which prevents. The water in the contaminant removal tank 140 is transferred to the carrier flow tank 150 through the transfer pipe 142.
The sludge extraction means 144 is a means having a function of extracting sludge containing contaminants (solid components) obtained by solid-liquid separation and transferring it to the sludge concentration storage tank 200. As the sludge extraction means 144, an air lift pump having a known configuration that sucks and discharges water to be treated by the air flow when air is supplied into the transfer pipe can be used.

The carrier flow tank 150 has an aerobic treatment region in which a large number of granular carriers C1 are filled so as to be flowable. The granular carrier C1 is formed in, for example, a hollow cylindrical shape, and aerobic microorganisms for aerobic treatment of organic contaminants in the water to be treated adhere to the granular carrier C1. The carrier fluid tank 150 is an area where the water to be treated before being filtered by the carrier filling unit 162 can stay.
The carrier flow tank 150 is provided with an advection tube 152 and an air diffuser 154.
The advection tube 152 is configured so that an inlet portion thereof is disposed in the vicinity of the water surface of the carrier flow tank 150 and extends below a carrier filling portion 162 of a carrier filtration tank 160 described later. In addition, a slit-shaped carrier separation device (not shown) that prevents the granular carrier C1 of the carrier flow tank 150 from flowing into the carrier filtration tank 160 is installed at the inlet portion of the advection tube 152. The water in the carrier flow tank 150 is transferred to the carrier filtration tank 160 through the transfer pipe 152.
The air diffuser 154 is a device that supplies air into the carrier fluid tank 150, fluidizes the particulate carrier C1 in the carrier fluid tank 150, and imparts oxygen to the aerobic microorganisms attached to the particulate carrier C1. It has a function. Thereby, the aerobic treatment (oxidative decomposition) of the organic matter in the treated water proceeds by the aerobic microorganism, and the removal of the BOD component in the treated water is efficiently performed. At this time, solid matter (SS) such as sludge (mud substance) is generated by aerobic treatment (oxidative decomposition) of organic matter.
In the present embodiment, the defoaming agent stored in the defoaming tank 190 can be supplied to the carrier flow tank 150. By supplying the antifoaming agent from the defoaming tank 190, it is possible to suppress foaming generated in the carrier fluidized tank 150.

  The carrier filtration tank 160 has a carrier filling portion 162 filled with the carrier C2 in a flowable manner, and includes a backwash device 164 below the carrier filling portion 162. The carrier filtration tank 160 is provided with return means 168, sludge extraction means 169, and the like.

  The carrier C2 filled in the carrier filling unit 162 is a sludge containing solid products such as SS (floating matter) generated by aerobic treatment in the carrier flow tank 150 and solid components contained in the water to be treated. Has the ability to capture. That is, when the water to be treated flows upward through the carrier filling portion 162 by an upward flow as indicated by an arrow in FIG. 2, sludge contained in the water to be treated is filtered and separated by the carrier C2. In the present embodiment, a floating granular carrier, that is, a carrier having an apparent specific gravity smaller than that of water is used as the carrier C2. The carrier C2 corresponds to the “filter medium” in the present invention and the aspect 1 to be described later, and the carrier filling part 162 filled with the carrier C2 corresponds to the “filtration processing part” in the present invention and the aspect 1 to be described later. ing.

  The backwashing device 164 is a device that supplies air into the carrier filtration tank 160 during backwashing processing (backwashing operation) that is performed periodically, and can supply air as backwashing fluid to the carrier filling unit 162. It has a configuration. By operating the backwashing device 164, a function (backwashing function) for separating the object to be filtered such as sludge trapped (filtered) by the carrier C2 from the carrier C2 is exhibited. The backwashing device 164 disposed below the carrier filling unit 162 corresponds to the “cleaning fluid supply means” in the present invention and the mode 1 described later, and the air supplied to the carrier filling unit 162 is This corresponds to the “cleaning fluid” in the invention and in aspect 1 described later. The matter to be filtered such as sludge separated from the carrier C2 by the backwashing function of the backwashing device 164 is settled and separated and collected in an inclined hopper 166 provided at the bottom of the carrier filtration tank 160. Yes.

The return means 168 is a means having a function of periodically returning the water after the object to be filtered such as sludge is filtered by the carrier C2 to the flow rate adjusting tank 120. Further, the sludge extraction means 169 has a function of extracting the sediment such as sludge accumulated at the bottom of the carrier filtration tank 160, that is, below the carrier filling section 162, and transferring it to the sludge concentration storage tank 200 by solid-liquid separation. Means. The sludge extraction means 169 corresponds to the “sediment discharge means” in the present invention and the aspect 1 described later.
As these return means 168 and sludge extraction means 169, as in the case of the sludge extraction means 144, an air lift pump having a known configuration that sucks and discharges water to be treated by the air flow when air is supplied into the transfer pipe. Can be used.
The water in the carrier filtration tank 160 is transferred to the disinfection tank 170 through the transfer opening.

  The disinfection tank 170 includes a disinfectant 172, and is configured to transfer the water after disinfection to the discharge pump tank 180 after appropriately disinfecting the water flowing from the carrier filtration tank 160. .

The discharge pump tank 180 has a function of temporarily storing the water subjected to the purification treatment and discharging the water stored in the tank. The discharge pump tank 180 is provided with a discharge pump 182 for discharging the purified water to the outside of the discharge pump tank 180 through the discharge port 103. The discharge pump 182 is configured as a so-called “submersible pump” set to be submerged in the discharge pump tank 180. In addition, the discharge pump 182 can also be comprised with an air lift pump instead of a submersible pump.
If necessary, the discharge pump tank 180 may be omitted, and the water treated in the disinfection tank 170 may be discharged out of the wastewater treatment tank 100 as it is.

The sludge concentration storage tank 200 has a function of storing deposits such as sludge extracted by the sludge extraction means 144 and 169 from the contaminant removal tank 140 and the carrier filtration tank 160 having the above-described configuration. The sediment such as sludge is solid-liquid separated in the sludge concentration storage tank 200 and then appropriately transported out of the sludge concentration storage tank 200 to be processed separately. This sludge concentration storage tank 200 corresponds to a “sediment storage region” in the present invention and the mode 2 described later.
The sludge concentration storage tank 200 is provided with a desorbed liquid return pipe 202 that allows the sludge concentration storage tank 200 and the flow rate adjustment tank 120 to communicate with each other. The desorbed liquid return pipe 202 has a configuration in which an inlet portion extends to an intermediate region of the water level in the tank, and sediments and deposits in the stored matter stored in the intermediate region of the sludge concentration storage tank 200, that is, the tank bottom. It has a function of returning the desorbed liquid staying between the sedimentary sludge (sludge) and the floating sludge (scum) floating in the upper part of the tank to the flow rate adjusting tank 120. This configuration corresponds to “a configuration in which the solid-liquid separated water in the sediment storage region is discharged out of the sediment storage region” in the present invention, and the flow rate adjustment tank 120 in this configuration is the “sediment in the present invention. It corresponds to “outside storage area”. By returning the desorbed liquid to the flow rate adjusting tank 120 through the desorbed liquid return pipe 202, the degree of sludge concentration in the sludge concentrated storage tank 200 can be increased.
The sludge concentration storage tank 200 is provided with a stirring device 204 having a function of stirring the water in the sludge concentration storage tank 200. By operating the agitation device 204 when the sludge is carried out, the water in the tank is agitated and the sludge can be easily drawn out when the sludge is carried out.

  Here, operation | movement of the support | carrier filtration tank 160 among the waste water treatment tanks 100 of the said structure is demonstrated, referring drawings. In the present embodiment, the carrier filtration tank 160 has the following three operation modes controlled by a timer (not shown), that is, normal operation, sludge extraction operation, and backwash operation. Furthermore, the backwashing operation is composed of four steps: a backwash preparation step, a backwash step, a sludge extraction step, and a treated water return step.

(Normal operation)
In the normal operation, the water to be treated that has flowed into the treatment tank main body 101 is aerated screen 110 → flow rate adjustment tank 120 → metering adjustment device 130 → contaminant removal tank 140 → carrier flow tank 150 → carrier filtration tank 160 → disinfection tank. It is processed in the order of 170 and discharged from the discharge pump tank 180.
Here, the state of the carrier filtration tank 160 in the normal operation mode is shown in FIG.
As shown in FIG. 3, in the carrier filtration tank 160 in the normal operation mode, water to be filtered, such as sludge, is obtained by the water aerobically treated in the carrier fluidization tank 150 flowing from below to above the carrier filling section 162. Is filtered and trapped by the carrier C2 and separated into solid and liquid (filtering treatment). Then, the water after the solid-liquid separation is transferred to the disinfection tank 170. This normal operation corresponds to the “filtration treatment operation” in the present invention and aspect 1 described later.

(Sludge extraction operation)
The state of the carrier filtration tank 160 in the sludge extraction operation mode is shown in FIG.
As shown in FIG. 4, in the carrier filtration tank 160 in the sludge extraction mode, sludge and the like settled and deposited on the bottom of the carrier filtration tank 160 (below the carrier filling part 162) by operating the sludge extraction means 169. The water containing the deposit is transferred (extracted) to the sludge concentration storage tank 200. The operation of the metering pump 122 of the flow rate adjusting tank 120 is stopped in this sludge extraction operation mode. This sludge extraction operation corresponds to the “sediment discharge operation” in the present invention and an aspect 1 described later.

(Backwash operation)
FIG. 5 shows the state of the carrier filtration tank 160 in the backwashing preparation process, and FIG. 6 shows the state of the carrier filtration tank 160 in the backwashing process, and the carrier filtration tank 160 in the sludge extraction process. 7 is shown in FIG. 7, and the state of the carrier filtration tank 160 in the treated water return step is shown in FIG. Note that the operation of the metering pump 122 of the flow rate adjusting tank 120 is stopped in this backwash mode.

  As shown in FIG. 5, in the carrier filtration tank 160 in the backwash preparation step, the return means 168 is operated before the backwash process, thereby transferring (returning) the water above the carrier filtration tank 160 to the flow rate adjustment tank 120. Then, the water level of the carrier filtration tank 160 is lowered. Thus, by lowering the water level of the carrier filtration tank 160 before the backwashing step, SS in the backwash water is prevented from flowing out to the disinfection tank 170 side in the subsequent backwashing process.

Next, a backwash process is performed following the backwash preparation process.
As shown in FIG. 6, in the carrier filtration tank 160 in the backwashing process, the operation of the return means 168 is stopped and the backwashing device 164 is operated. When the backwashing device 164 is activated and air is supplied into the carrier filtration tank 160, the carrier C2 filled in the carrier filling unit 162 is stirred by this air flow, and the sludge or the like trapped in the carrier C2 is covered. Filtrate peels off. Thereby, the washing | cleaning process of the support | carrier C2 will be performed. In particular, in the present embodiment, air is used as the backwashing fluid of the carrier C2, and therefore, in addition to the cleaning effect by the water flow formed by air, for example, the air itself as compared with the case where water is used as the cleaning fluid. As a result, the cleaning effect of the carrier C2 in the carrier filling portion 162 is enhanced. This back-washing process corresponds to the “washing operation” in the present invention and aspect 1 described later.
As described above, since the floating granular carrier is used as the carrier C2 in the present embodiment, the carrier in the backwashing step is compared with the case where a sedimentary granular carrier having an apparent specific gravity larger than that of water is used. C2 has good fluidity and is effective in improving the backwashing efficiency of the carrier C2. In other words, when a sedimentary granular carrier is used, the carrier may partially stay in the carrier filling portion and is difficult to fluidize, but the floating granular carrier flows smoothly through the carrier filling portion. The backwash efficiency is improved. Accordingly, the frequency of the backwashing operation itself can be suppressed as the cleaning efficiency of the carrier C2 is improved, and it is reliably prevented that the time required for the water quality to stabilize immediately after the backwashing operation is increased. As described above, the configuration using the floating granular carrier as the filter medium is effective in preventing the backwash operation from being performed excessively more than necessary.

Next, a sludge extraction step is performed following the backwashing step.
As shown in FIG. 7, in the carrier filtration tank 160 in the sludge extraction step, the sludge extraction means 169 is operated to remove water containing sediment such as sludge that has settled and deposited on the bottom of the carrier filtration tank 160. Transfer to 200 (extract).
In this sludge extraction step and the sludge extraction operation, sediments such as sludge transferred to the sludge concentration storage tank 200 are separated in the sludge concentration storage tank 200. In the sludge concentration storage tank 200, the flow rate of the desorbed liquid between the sedimentary sludge (sludge) that has settled and accumulated at the bottom of the tank and the floating sludge (scum) that floats at the top of the tank is adjusted through the desorbed liquid return pipe 202. By returning to the tank 120, the sludge concentration process in the sludge concentration storage tank 200 is performed.

Next, a treated water return process is performed following the sludge extraction process.
As shown in FIG. 8, in the carrier filtration tank 160 in the treated water return step, the metering pump 122 of the flow rate adjustment tank 120 is operated to restore the water level of the carrier filtration tank 160. At the same time, by operating the return means 168, the water in the upper part of the carrier filtration tank 160 is transferred (returned) to the flow rate adjusting tank 120 so that there is no advection to the disinfection tank 170. Thus, by transferring (returning) the water in the upper part of the carrier filtration tank 160 to the flow rate adjustment tank 120, the SS floating in the tank after the backwashing process is prevented from flowing out to the disinfection tank 170 side. .
In addition, when this process water return process is complete | finished, it returns to the said normal driving | operation.

In the present embodiment, a predetermined time schedule is set for the sludge extraction operation and the backwash operation in the carrier filtration tank 160. Here, an example of the time schedule regarding the sludge extraction operation and the backwash operation in the carrier filtration tank 160 is shown in FIG. FIG. 9 shows the sludge extraction operation for a total of 5 times (# 1 to # 5) and the backwash operation for a total of 2 times (# 1 and # 2).
As shown in FIG. 9, in the present embodiment, the sludge extraction operation shown in FIG. 4 is performed every 6 hours (operation interval is 6 hours), and the backwash operation shown in FIGS. The interval is set to be 24 hours). This aspect corresponds to an aspect of the present invention that “the operation interval of the deposit discharge operation is less than the operation interval of the cleaning operation”. That is, in this embodiment, every time the sludge extraction operation is performed four times, the backwash operation (especially the backwash process) is performed once, and the number of sludge extraction operations per day is the number of backwash operations per day. It is set to be larger than the number of driving.

Here, the number of sludge extraction operations and backwash operations as described above and the setting of the operation time interval are based on the following reasons.
That is, in the configuration in which the water to be treated flows from the lower side to the upper side of the carrier filling portion 162 of the carrier C2 as in the present embodiment, the matter to be filtered such as sludge filtered by the carrier C2 is separated from each of the carrier filling portions 162. Of the carrier C <b> 2 at the site, the carrier C <b> 2 is particularly likely to be trapped in the vertical direction, and the trapped SS tends to settle to the bottom of the carrier filtration tank 160 as it is. Therefore, even if the sludge extraction operation is not performed in accordance with the backwash operation, the sludge extraction operation is performed more frequently than the backwash operation as in this embodiment, so that sludge to the outside of the carrier filtration tank 160 can be removed. It is effective to enhance the sediment discharge effect. On the other hand, when sludge extraction operation is performed in conjunction with backwash operation, or when the number of backwash operations is increased more than the number of sludge extraction operations, the time required for water quality to stabilize immediately after backwash operation As a result, the backwash operation is performed excessively more than necessary.

  Moreover, according to the setting which divides the frequency | count of the sludge extraction operation | movement per day into multiple times like this Embodiment, compared with the case where sludge extraction operation is performed about once a day, deposits, such as sludge. At the same time, the amount of water transferred to the sludge concentration storage tank 200 can be suppressed. Thereby, it becomes possible to prevent useless sludge extraction operation to unnecessarily extract water other than sediment such as sludge. Moreover, the setting which divides the frequency | count of the sludge extraction operation per day into multiple times is compared with the case where a large amount of water is transferred to the sludge concentration storage tank 200 from the carrier filtration tank 160 at a time together with deposits such as sludge. This is effective in improving the solid separation performance of sludge and desorbed liquid in the sludge concentration storage tank 200. That is, when a large amount of water is transferred from the carrier filtration tank 160 to the sludge concentration storage tank 200 at a time together with deposits such as sludge, it is returned from the sludge concentration storage tank 200 to the flow rate adjustment tank 120 through the desorbed liquid return pipe 202. Since the flow rate of the desorbed liquid increases and the possibility that sludge is mixed into the desorbed liquid increases, the solid-liquid separation performance between the sludge and the desorbed liquid in the sludge concentration storage tank 200 decreases. On the other hand, as in this embodiment, the number of operations of the sludge extraction operation per day is divided into a plurality of times, and the amount of water transferred at one time from the carrier filtration tank 160 to the sludge concentration storage tank 200 is suppressed. The increase in the flow rate of the desorbed liquid returned from the sludge concentration storage tank 200 to the flow rate adjustment tank 120 through the desorbed liquid return pipe 202 can be suppressed, and the sludge and desorbed liquid in the sludge concentration storage tank 200 can be prevented. It becomes possible to improve the solid-liquid separation performance.

Here, it is preferable to set the interval between the sludge extraction operations in the carrier filtration tank 160 based on the residence time of the water to be treated in the carrier fluidized tank 150 which is the previous tank (upstream area tank) of the carrier filtration tank 160. . In the present embodiment, in consideration of the residence time of the water to be treated in the carrier fluidized tank 150, the sludge extraction operation interval in the carrier filtration tank 160 is set to about 6 hours. As a result, each time the water containing the object to be filtered such as sludge is transferred to the carrier filtration tank 160 in the carrier flow tank 150 and the water in the carrier flow tank 150 is replaced, the sludge accumulated on the bottom of the carrier filtration tank 160 is accumulated. As a result, the deposits such as sludge accumulated on the bottom of the carrier filtration tank 160 can be surely extracted, and water other than the deposits such as sludge should not be drawn out together with the deposits. It becomes possible to perform a fine sludge extraction operation.
Moreover, the energy-saving effect regarding a backwash operation increases by restraining the frequency | count of a backwash operation to once a day like this Embodiment.

  In addition, this invention is not limited to the said embodiment about the driving | operation interval of a sludge extraction operation | movement and a backwash operation, and the frequency | count of an operation | movement per day. For example, when the operation interval of the sludge extraction operation is less than the operation interval of the backwash operation, the operation interval of the sludge extraction operation and the backwash operation is appropriately set, or the number of sludge extraction operations per day is The number of times of sludge extraction operation and backwash operation can be set as appropriate under the condition that the number of backwash operations is exceeded.

[Other Embodiments]
In addition, this invention is not limited only to said embodiment, A various application and deformation | transformation can be considered. For example, each of the following embodiments to which the above embodiment is applied can be implemented.

  In the above-described embodiment, the case where the floatable granular carrier 162 is filled in the carrier filling section 162 of the carrier filtration tank 160 has been described. However, a sedimentary granular carrier can be filled instead of the floatable granular carrier. Moreover, it is good also as a structure which filled the support | carrier filling part 162 with filter media other than a granular support | carrier, for example, the filter medium comprised by a regular packing.

  Moreover, in the said embodiment, although the operation interval of sludge extraction operation was 6 hours every time and the operation interval of backwash operation was 24 hours each time, the operation interval of sludge extraction operation and backwash operation is constant every time. There is no need, and it may be different every time or every predetermined time, or may be set differently depending on the operating conditions, seasons, and the like.

  In the above embodiment, the case where the carrier C2 is backwashed by supplying air to the carrier filling unit 162 during the backwash operation is described. However, the backwashing fluid used for backwashing the carrier C2 is air. Other fluids may be used. For example, a gas other than air, water, or the like can be used as the backwash fluid.

  Moreover, in the said embodiment, about the kind of each tank which comprises the waste water treatment tank 100, a number, arrangement | positioning, etc. can be suitably changed as needed.

  Moreover, in view of the said embodiment and the form of various changes, in this invention, the structure as described in the following aspects 1-aspect 4 can be taken.

(Aspect 1)
According to the present invention, “at the time of the filtration treatment operation, the water to be treated is caused to flow from the lower side to the upper side of the filtration treatment unit with respect to the filtration treatment unit filled with the filter medium for performing the filtration treatment of the water to be treated. Filter the treated water,
During the cleaning operation, the filtration processing unit is cleaned by supplying a cleaning fluid to the filtration processing unit,
A wastewater treatment method for performing a process of discharging deposits deposited below the filtration unit during the deposit discharge operation,
The wastewater treatment method, wherein an operation interval of the deposit discharge operation is set to be less than an operation interval of the cleaning operation. The configuration (embodiment 1) can be adopted.

In this aspect 1, during the filtration treatment operation, the water to be treated is caused to flow from the lower side to the upper side of the filtration treatment unit with respect to the filtration treatment unit filled with the filter medium for performing the filtration treatment of the water to be treated. Filter the treated water. The filtration processing unit has the same configuration as the filtration processing unit according to claim 1.
Further, during the cleaning operation, the filtration processing unit is cleaned by supplying a cleaning fluid to the filtration processing unit. In order to supply the cleaning fluid to the filtration processing unit, means having the same configuration as the cleaning fluid supply means according to claim 1 can be used.
Further, during the deposit discharging operation, a process of discharging the deposit deposited below the filtration processing unit is performed. In order to discharge the deposit deposited below the filtration processing unit, means having the same configuration as the deposit discharging means according to claim 1 can be used.
In particular, in the first aspect, the operation interval of the deposit discharge operation is set to be shorter than the operation interval of the cleaning operation. This aspect 1 means that the frequency | count of operation of the sediment discharge | emission driving | operation per day exceeds the driving | operation frequency | count of the washing | cleaning operation per day, for example.
If such a waste water treatment method described in the first aspect is used, the effect of increasing the sediment discharge effect, the effect of suppressing the amount of water discharged together with the deposit, and the cleaning operation, similar to the effect described in claim 1 It has energy-saving effects.

(Aspect 2)
Further, in the present invention, “the wastewater treatment method according to aspect 1,
A wastewater treatment method characterized in that deposits discharged through the deposit discharge means are stored in a deposit storage area, and water separated into solid and liquid in the deposit storage area is discharged outside the deposit storage area. . The configuration (Aspect 2) can be adopted.

In this aspect 2, in the wastewater treatment method according to aspect 1, the deposit discharged through the deposit discharging means is stored in the deposit storage region, and the water separated in the deposit storage region is subjected to solid-liquid separation. Discharge out of area.
If such a wastewater treatment method described in the second aspect is used, it is possible to suppress an increase in the flow rate of water discharged out of the deposit storage area, similarly to the effect described in the second aspect. It becomes possible to improve the solid-liquid separation performance in the storage region.

(Aspect 3)
Further, in the present invention, “the wastewater treatment method according to aspect 1 or aspect 2,
A wastewater treatment method, wherein a floating granular carrier is used as a filter medium filled in the filtration unit. The configuration (Aspect 3) can be adopted.

In aspect 3, in the wastewater treatment method according to aspect 1 or aspect 2, a floating granular carrier is used as the filter medium filled in the filtration unit.
If such a wastewater treatment method according to the third aspect is used, as in the case of the effect described in the third aspect, compared to the case where a sedimentary carrier having an apparent specific gravity larger than that of water is used, Cleaning efficiency can be improved. Accordingly, the frequency of the cleaning operation itself can be suppressed as the carrier cleaning efficiency is improved, and it is reliably prevented that the time required for the water quality to stabilize immediately after the cleaning operation is increased.

(Aspect 4)
Moreover, in the present invention, “the wastewater treatment method according to any one of aspects 1 to 3,
A wastewater treatment method for performing a cleaning process of the filtration processing unit by supplying air as a cleaning fluid from below the filtration processing unit to the filtration processing unit during a cleaning operation. (Configuration 4).

In this aspect 4, in the waste water treatment method according to any one of the aspects 1 to 3, air is used as a cleaning fluid for the filtration processing unit.
If such a waste water treatment method described in the fourth aspect is used, the cleaning effect by the water flow formed by the air and the cleaning effect by the bubbling of the air itself are synergistically similar to the effect described in the fourth aspect. As a result, the cleaning treatment effect of the filter medium in the filtration processing section is enhanced.

It is a figure which shows the processing flow of the waste water treatment tank 100 of one Embodiment in this invention. It is a figure which shows the internal structure of the processing tank main body 101 of the waste water processing tank. It is a figure which shows the state of the carrier filtration tank 160 in the mode of normal operation. It is a figure which shows the state of the carrier filtration tank 160 in the mode of sludge extraction operation | movement. It is a figure which shows the state of the support | carrier filtration tank 160 in the backwashing preparation process of the mode of backwashing operation. It is a figure which shows the state of the carrier filtration tank 160 in the backwashing process of the mode of backwashing operation. It is a figure which shows the state of the support | carrier filtration tank 160 in the sludge extraction process of the mode of a backwash operation. It is a figure which shows the state of the support | carrier filtration tank 160 in the process water return process of the mode of a backwash operation. It is a figure which shows an example of the time schedule regarding the sludge extraction operation | movement in the support | carrier filtration tank 160, and a backwash operation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Waste water treatment tank 101 ... Treatment tank main body 102 ... Inlet 103 ... Outlet port 110 ... Aeration type screen 120 ... Flow rate adjustment tank 122 ... Metering pump 124,204 ... Stirrer 130 ... Metering adjustment apparatus 140 ... Contaminant removal tank Reference numerals 142, 152, advection pipes 144, 169, sludge extraction means 150, carrier fluid tank 154, air diffuser 160, carrier filtration tank 162, carrier filling section 164, backwash apparatus 166, hopper section 168, return means 170, disinfection tank 180 ... discharge pump tank 190 ... defoaming tank 200 ... sludge concentration storage tank 202 ... desorbed liquid return pipe

Claims (4)

A filtration processing unit filled with a filter medium for filtering the water to be treated, a cleaning fluid supply means capable of supplying a cleaning fluid to the filtration processing unit, and deposits deposited below the filtration processing unit are discharged. A wastewater treatment device having possible sediment discharge means,
The water to be treated is filtered by flowing the water to be treated from below to above in the filtration treatment operation,
The filtration processing unit used for the filtration treatment of the water to be treated is washed by operating the washing fluid supply means during the washing operation,
It is a configuration in which deposits deposited below the filtration processing unit are discharged by operating the deposit discharge means during deposit discharge operation,
The waste water treatment apparatus is configured such that an operation interval of the deposit discharge operation is less than an operation interval of the cleaning operation. A wastewater treatment apparatus according to claim 1,
A deposit storage area for storing the deposit discharged through the deposit discharging means is provided, and water separated into solid and liquid in the deposit storage area is discharged outside the deposit storage area. A wastewater treatment apparatus characterized by that. The wastewater treatment apparatus according to claim 1 or 2,
A wastewater treatment apparatus characterized in that a floating carrier is used as a filter medium filled in the filtration unit. The wastewater treatment apparatus according to any one of claims 1 to 3,
The wastewater treatment apparatus, wherein the cleaning fluid supply means is configured to be able to supply air as the cleaning fluid to the filtration processing unit from below the filtration processing unit.

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