JPH0521602B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to a cobblestone filtration device for tertiary treatment of septic tanks. Conventionally, tertiary treatment of septic tanks has been carried out using the biofilm method, which consists of a contact oxidation tank and a settling tank, and in this case, the contact oxidation tank mainly uses a laminated product of vinyl chloride sheets as a contact material. ing. Although this can ensure water quality in the short term, in the long term, the produced film formed in the contact oxidation tank tends to peel off. First, the treated water in this state was discharged outside the facility, resulting in a lack of stability in long-term purification treatment and was still insufficient in preventing water pollution. In particular, the standard pH value for discharge is 5.8 to 8.5.
However, when the secondary treatment water is subjected to tertiary treatment, if honeycomb is used as a contact material as described above, the kiln element content will be oxidized and digested by continuing and promoting the aerobic condition. During the process, the pH dropped to about 4 to 5, which required repeated pH adjustments.

The present invention was devised in view of the above-mentioned points. Natural stones, that is, cobblestones of different sizes are piled up in multiple stages in a rostre provided at the lower part of the tertiary treatment tank, and a water collection pipe is installed in the lower chamber below the rostrum. Alternatively, install a water collection backwash pipe that has both a water collection function and an air backwash function using an air bubble link, and install an aeration pipe in the upper room above the natural stone. ,
We provide a cobblestone filtration device for tertiary treatment consisting of various configurations such as installing backwash troughs above the normal water level in the upper chamber, and use this to improve the quality of discharged water and stabilize PH, etc. It is.

An embodiment of the present invention will be described with reference to a case where one rectangular boulder tank T is provided as shown in FIGS. 1 and 2.

1 is the sewage inlet pipe for the secondary treatment water, which has a BOD of 20 to 60 ppm in the sedimentation tank (not shown) in the previous process.
Wastewater that has been subjected to secondary treatment to COD: 20 to 60 ppm and SS: 20 to 60 ppm is allowed to flow into the concrete boulder overtank T of the present invention. Reference numeral 2 denotes a bottom-shaped lower chamber at the bottom of the overtank T, and an engaging stepped portion 3 of a rostol, which will be described later, is provided at the front and rear of the lower chamber. Reference numeral 4 denotes concrete ropes having a rectangular cross section supported at both ends by the engaging step portion 3, and are arranged in parallel at regular intervals of about 50 to 75 mm. 5 and 5a are rounded natural stones stacked in multiple tiers, that is, two tiers, on the upper part of Rostle 4, that is, cobblestones that allow aerobic microorganisms to adhere and propagate.
A boulder 5 with a relatively large diameter is placed in the upper part.
Each relatively small boulder 5a with a diameter of 30 to 60 mm is
They are piled up to a height of about 75 to 50 cm. Depending on the quality of the water that has undergone secondary treatment, the upper part may contain 60~
Pile up medium-sized boulders with a diameter of about 100 mm. Also,
These three types of boulders 5, 5a, 5b of different sizes
30 to 60 mm in the upper part as shown in the modified example in Figure 7.
Place a cobblestone 5a about the diameter of 60 to 100 on the upper side of the lower part.
A cobblestone 5b with a diameter of about mm is placed on the bottom side of the boulder 5b
It is also possible to stack up boulders 5 each having a diameter of about 150 mm. Reference numeral 6 denotes a relatively large-diameter water collection pipe installed horizontally on the lower side of the lower chamber 2, and as shown in Figure 5a, there are water holes with a diameter of about 15 mm on both sides and the lower part of the horizontally installed water collection pipe 6. 7 are drilled in the longitudinal direction at a pitch of approximately 100 mm. Reference numeral 8 denotes a water passage pipe for the tertiary treated water that has flowed into the water collection pipe 6, which is raised from the end of the water collection pipe 6 and allowed to naturally flow out to the backwash tank 9 for the next process. Reference numeral 10 denotes an on-off valve provided at the end of the water pipe 8, which is normally left open. 1
Reference numeral 1 denotes an air backwash pipe installed on the upper side of the lower chamber 2 in parallel with the water collection pipe 6 at right angles, and as shown in FIG.
However, as shown in Figure 6, the air backwash pipes 11 are installed directly below the rostre 4 at a pitch of about 10 to 15 cm every other time.
Branch piping is installed in parallel with the Reference numeral 13 denotes an air supply pipe for air backwashing, one end of which is connected to the air backwashing pipe 11, raised above the tank T, and air is supplied from a separate air blower B by opening an on-off valve 14. Reference numeral 15 denotes an upper chamber above the stacked boulders 5, 5a, and 5b, in which the secondary treated water flowing in from the wastewater introduction pipe 1 is stored up to about the water level line WL of the overtank T. Reference numeral 16 denotes an air diffuser pipe arranged in a planar shape in the lower part of the upper chamber 15; 17 is an air supply pipe for air diffusion;
One end is connected to the air diffuser pipe 16 and raised upward, and the opening/closing valve 18 is connected to the air supply blower B at the other end.
is opened and air is supplied. Reference numeral 19 indicates a backwash water pipe which branches from a position immediately before the valve 10 of the water pipe 8 and is connected to the backwash tank 9; 20 indicates an on-off valve provided at the end of the branched backwash water pipe 19; and 21 is a water supply pump for backwashing the tertiary treated water that is installed in the water pipe 19 for backwashing, and after closing the valve 10, the valve 20 is opened, and the water supply pump 21 is operated to flush the backwash tank 9. The tertiary treated water pumped up from the drain pipe 8 is made to back-flow from the water passage hole 7 of the water collection pipe 6 through the water passage pipe 8. 22 is a backwash trough installed horizontally in the upper part of the overtank T, and 23 is a return pipe connected to the backwash trough 22 at one end, which collects scum that floats and floats as the water level rises during backwashing. The treated water is returned to the sludge pit or inflow pump tank in the previous process.
24 is a large-diameter cleaning pipe, which is passed from above the upper chamber 15 between the stones 5, 5a, 5b and the rostres 4 arranged in parallel, and is lowered to the lower chamber 2 and supported vertically. A vacuum hose (not shown) is inserted from the lower chamber 2 to pump up the sludge accumulated in the lower chamber 2. 26 is a disinfection tank connected to the backwash tank 9.

Therefore, to explain the tertiary treatment method of the secondary treated water using this device, first, the secondary treatment is performed up to the purification device (not shown) in the previous step, and the BOD is 20 to 60 ppm.
Secondary treated water with a COD of about 20 to 60 ppm and an SS of about 20 to 60 ppm is made to flow into the upper chamber 15 of the cobblestone tank T from the wastewater introduction pipe 1. This inflowing sewage is aerated by an aeration device composed of an aeration pipe 16, an aeration supply pipe 17, and a blower B, thereby increasing dissolved oxygen DO in the upper chamber 15 and , 5b, and then gradually passes through the multi-tiered boulders 5, 5a, 5b and settles down. While passing through the boulders, the fine suspended solids are physically filtered out and at the same time are subjected to biological treatment by microorganisms attached to the boulders 5, 5a, and 5b. Therefore, highly treated water with BOD, COD, and SS below 10ppm can be obtained. The treated water that has been overtreated in this way and has descended to the lower chamber 2 flows through the water passage hole of the water collection pipe 6 in conjunction with the supply of new secondary treated water from the wastewater introduction pipe 1 into the upper chamber 15. Valve 10 enters the water collection pipe 6 from 7, ascends the water pipe 8, and opens the valve 10.
The water is washed away into the backwash tank 9 through the sterilization chamber 26 and discharged to the outside, or is reused as gray water for flush toilets, water sprinkling, and fountains.

Tertiary treatment of the secondary treated water is normally carried out in this way, but due to long-term operation, the gaps formed between the stacked stones 5, 5a, 5b become narrowed and clogged. Before such a situation arises, or in cases where the quality of the tertiary treated water has deteriorated, it is necessary to start the operation of the air diffuser in the upper chamber 15, which is composed of the air diffuser pipe 16 and the air supply pipe 17 for air diffusion. stop,
After closing the valve 10 at the end of the water pipe 8 and opening the valve 20 of the backwash water pipe 19, the backwash water supply pump 21 is driven to pump up the tertiary treated water from the cleaning tank 9, and the backwash water is pumped up. From the washing water pipe 19 to the water pipe 8,
The water collection pipe 6 is made to flow backwards, and the water is discharged from its water passage hole 7.
The air backwashing device consisting of the air supply pipe 13 for air backwashing and the blower B is driven. Then, the air ejected from the blowhole 12 of the air backwash pipe 11 flows into the sixth
As shown in the figure, the air blows up from the gap between the rostles 4, and further rises and passes between the boulders 5, 5a, and 5b while bubbling air. With this, the SS that narrows the gap between the boulders 5, 5a, and 5b,
While removing it, it is floated to the surface layer of the upper chamber 15.
At the same time, the water level in the upper chamber 15 rises from the normal water level WL in the upper chamber 15 to the overflow height H into the backwash trough 22 due to the backwash water jetting out from the water passage hole 7 of the water collection pipe 6. . Therefore, the treated water containing floating matter floating on the surface layer is flowed into the backwash trough 22 and returned through the return pipe 23 to the sludge pit or inflow pump tank of the previous process. After such operation, normal operation is resumed.

In the above case, we have explained the case where there is only one cobblestone overtank T, but by installing another cobblestone overtank T1 having the same configuration as the said overtank T, as shown in Figs. 8 and 9, Even better tertiary treatment can be performed. Its basic structure and operation are as described in the first
Since this is the same as in the embodiment, it will be omitted. However, in order to allow the treated water to flow naturally from the first overtank T to the second overtank T1, the water level WL1 of the second overtank T1 was set low. It is structured as follows. Therefore, the drawing numbers indicating the same configuration as the first embodiment will be denoted by the symbol a, and the explanation thereof will be omitted.

FIG. 10 shows a modification of the first and second embodiments, in which the air backwash pipe 11 is removed from the lower chamber 2 and the backwash air supply pipe 13 is connected to the water pipe 8.
Therefore, during backwashing, the tertiary treated water from the backwash tank 9,
The mixture with air from blower B flows through the water collection backwash pipe 6.
Water is ejected from the water passage/ventilation hole 7, and the gaps between the boulders 5, 5a, 5b are aerated and air bubbled.

As mentioned above, the present invention provides an overtank T for tertiary treatment.
A sewage inlet pipe 1 and a backwash trough 22 for secondary treated water are provided in the upper part, a rostre 4 is provided in the lower part of the tank T, and a cobblestone on which aerobic microorganisms are attached and propagated is provided in the upper part of the rostre 4. 5, 5a are piled up in multiple stages, of which relatively large boulders 5 with a diameter of about 100 to 150 mm are placed in the lower part, and relatively small boulders 5a with a diameter of about 30 to 60 mm or boulders 5 with a diameter of 60 to 100 mm are placed in the upper part. Medium-sized boulders are piled up and down to a height of about 75 to 50 cm, respectively, and the lower chamber 2 at the bottom of the rostre 4 has a collection of tertiary treated water with water holes 7 drilled on both sides and the lower part. A water pipe 6 is installed horizontally, and an air backwash pipe 11 with blowholes 12 perforated on both sides is installed on the upper side of the lower chamber 2 and is perpendicular to the water collection pipe 6 and directly below the rostrum 4. A diffuser pipe 16 is installed in the upper chamber 15 above the boulders 5, 5a, and the air backwash pipe 11 is equipped with an air supply pipe 13 for air backwash and an on-off valve. 14 is connected to the air diffuser pipe 16, and an air diffuser air supply pipe 17 and an on-off valve 18 are connected to the air diffuser pipe 16, and the air diffuser air supply pipe 17 and the air backwash air supply pipe 13 are merged and connected to the blower B. ,
An on-off valve 10 is attached to the water pipe 8 for the tertiary treated water connected to the water collection pipe 6, and the water pipe 8 and the backwash tank 9 are connected by a water pipe 19 for backwashing. A cobblestone filtration device in which an on-off valve 20 and a backwash water supply pump 21 are connected to a water pipe 19, and a cleaning pipe 24 for pumping up sludge in the lower chamber 2, which runs vertically from above the upper chamber 15 to the lower chamber 2, is supported in an upright manner. We have provided several types of cobblestone filtration equipment for tertiary treated water, including
In addition to improving dissolved oxygen through aeration from the aeration pipe, oxygen is quickly supplied to the microorganisms attached to the cobblestones. Physical overtreatment of suspended solids and biofilm treatment by the adherent microorganisms are carried out smoothly and quickly. In particular, in the case of a combination of an upper overlayer made of anthracite and a lower overlayer made of sand or gravel in the previous Japanese Patent Application Publication No. 57-48388, or in the case of a combination of an upper overlayer made of anthracite and a lower overlayer made of sand or gravel, or in the case of a combination of a grain size of about 1.2 mm in Japanese Patent Publication No. 56-14360, Upper overlayer with anthracite or granular activated carbon, gravel or grain size
In the case of combinations of lower overlayers made of silica sand of about 1.0 mm, the main focus was simply physical treatment of overlayering of treated water.

However, in the present invention, by adopting significantly larger boulders, the physical processing function is not limited to being achieved. 30 to 60 in the upper section
A combination of relatively small boulders with a diameter of about mm or medium boulders with a diameter of about 60 to 100 mm may be stacked up and down to a height of about 75 to 50 cm, or a stone with a height of 100 to 150 mm may be stacked on the bottom side of the lower part. A relatively large boulder with a diameter of about 60 to 100 mm is placed on the upper side, a relatively small boulder with a diameter of about 30 to 60 mm is placed on the upper part, and the top and bottom are each 75 to 75 mm in height. Since the combination is stacked about 50 cm, it actively promotes the inhabitation and reproduction of aerobic microorganisms around each boulder, and the secondary treated water flows down through the rough gaps between these boulders, thereby reducing the amount of water in question. Biological treatment such as adsorption, oxidation, and decomposition by aerobic microorganisms in the cobblestone layer is actively carried out. As a result, the PH of the tertiary treated water is stabilized, contributing to the improvement of water quality, and the effect of removing the kiln content is also extremely high, so the tertiary treated water can be reused as gray water for car washing, flushing, etc. can. In addition, a water collection pipe or water collection backwash pipe is installed in the lower chamber, and the treated water is naturally sucked in and passed through the water passage holes or water passage/ventilation holes on both sides and the lower part, or the water is passed in the reverse direction. Since the treated water in the backwash tank is back-flowed from the water hole or water flow/ventilation hole, it is necessary to prevent clogging of the water flow hole or water flow/ventilation hole, and to prevent water collection pipes, water collection backwash pipes, and water flow. It also makes it possible to clean the inside of the pipe. In addition, by installing air backwash pipes or water collection backwash pipes directly below the rostrum, air jets or air and water are ejected from the vents on both sides of the pipes, preventing clogging. This brings about various effects such as a cleaning effect between the stones due to the good bubbling effect from the gap between the stones and the stones.

[Brief explanation of the drawing]

Figure 1 is a vertical front view of the device showing a single cobblestone tank, Figure 2 is its plan view, Figure 3 is a partially cutaway plan view of the lower part of the rostre, and Figure 4 is a vertical side view of the lower chamber. , Figures 5a and b are cross-sectional views of the water collection pipe and air backwash pipe, Figure 6 is a longitudinal cross-sectional view showing the positional relationship between the rostre and air backwash pipe, and Figure 7 is a case in which cobblestones are stacked in three stages. FIGS. 8 and 9 are a longitudinal sectional front view and a plan view of a case where two boulder overtanks are installed in series, and FIG. 10 is a longitudinal sectional front view showing another embodiment. Code list, T...tank, B...blower, 1...
Sewage introduction pipe, 1...lower chamber, 3...stepped section, 4...
Rostle, 5... Cobblestone, 6... Water collection pipe or water collection backwash pipe, 7... Water passage hole, 8... Water passage pipe, 9... Backwash tank, 10, 14, 18, 20... Valve, 11...
... Air backwash pipe, 12 ... Fumarole, 13 ... Air supply pipe for backwash, 15 ... Upper chamber, 16 ... Diffusion pipe, 17
... Air supply pipe for aeration, 19 ... Water pipe for backwashing, 21
... Backwash water supply pump, 22 ... Backwash trough, 2
3... Return pipe, 24... Cleaning pipe, 26... Disinfection room.

Claims (1)

[Scope of Claims] 1. A sewage inlet pipe 1 and a backwash trough 22 for secondary treated water are provided in the upper part of the tertiary treatment tank T, and a rostre 4 is provided in the lower part of the tertiary tank T. At the top of the cobblestones, boulders 5 and 5a for adhering and propagating aerobic microorganisms are piled up in multiple tiers, among which relatively large boulders 5 with a diameter of about 100 to 150 mm are placed in the lower tier, and stones 5 with a diameter of 30 to 60 mm are placed in the upper tier. relatively small boulder 5a
Alternatively, pile up medium-sized cobblestones of about 60 to 100 mm in diameter to a height of about 75 to 50 cm on the top and bottom, respectively.
On the lower side of the lower chamber 2 in the lower part, a collection pipe 6 for tertiary treated water with water passage holes 7 bored on both sides and the lower part is installed horizontally. An air backwash pipe 11 with a fumarole hole 12 perforated therein is orthogonal to the water collection pipe 6, and is branched in parallel to the right below the rostre 4, and is connected to the upper chamber 15 above the boulders 5, 5a. An air diffuser pipe 16 is connected to the air backwash pipe 11, and an air backwash air supply pipe 13 and an open/close valve 14 are connected to the air diffuser pipe 16. A valve 18 is connected to connect the air supply pipe 17 for aeration and the air supply pipe 13 for air backwashing to be connected to the blower B, and an on-off valve 10 is connected to the water flow pipe 8 for the tertiary treated water connected to the water collection pipe 6. and connect the water pipe 8 and the backwash tank 9 to the backwash water pipe 1.
9, an on-off valve 20 and a backwash water supply pump 21 are connected to the backwash water pipe 19, and a lower chamber 2 extends vertically from above the upper chamber 15 to the lower chamber 2.
A cobblestone filtering device characterized in that a cleaning pipe 24 for pumping up sludge is vertically supported. 2 A sewage inlet pipe 1 and a backwash trough 22 for secondary treatment water are provided in the upper part of the tertiary treatment tank T, a rostre 4 is provided in the upper part of the tertiary tank T, and a suitable Cobblestones 5, 5a, and 5b on which airborne microorganisms can adhere and propagate are piled up in multiple tiers, and among them, a relatively large cobblestone 5 with a diameter of about 100 to 150 mm is placed on the lower side of the lower tier, and a relatively large cobblestone 5 with a diameter of about 60 to 100 mm is placed on the upper side. A medium-sized cobblestone 5b is placed in the upper part, and a relatively small cobblestone 5a with a diameter of about 30 to 60mm is placed in the upper and lower parts, respectively.
They are piled up about 75 to 50 cm, and there are water holes 7 on both sides and the lower part of the lower chamber 2 at the bottom of the rostle 4.
A collection pipe 6 for tertiary treated water is installed horizontally, and fumarole holes 12 are installed on both sides of the upper part of the lower chamber 2.
An air backwash pipe 11 with a perforation is arranged perpendicularly to the water collecting pipe 6 and is arranged in parallel directly below the rostrum 4 to branch into the upper chamber 15 above the boulders 5, 5a, 5b. An air diffuser pipe 16 is connected to the air backwash pipe 11, and an air backwash air supply pipe 13 and an on-off valve 14 are connected to the air diffuser pipe 16. , the diffuser air supply pipe 17 and the air backwash air supply pipe 13 are connected to the blower B, and the on-off valve 10 is attached to the tertiary treated water water flow pipe 8 connected to the water collection pipe 6. Then, the water pipe 8 and the backwash tank 9 are connected to the water pipe 1 for backwashing.
9, an on-off valve 20 and a backwash water supply pump 21 are connected to the backwash water pipe 19, and a cleaning pipe 24 for pumping up sludge that runs vertically from above the upper chamber 15 to the lower chamber 2 is erected and supported. A cobblestone filtering device that is characterized by: 3. A sewage inlet pipe 1 and a backwash trough 22 for secondary treated water are provided in the upper part of the tertiary treatment tank T, a rostre 4 is provided in the lower part of the tertiary tank T, and a suitable Cobblestones 5, 5a that allow airborne microorganisms to adhere and propagate are stacked in multiple tiers, with relatively large pebbles 5 with a diameter of about 100 to 150 mm in the lower tier and relatively small pebbles 5a with a diameter of 30 to 60 mm in the upper tier.
Alternatively, pile up medium-sized cobblestones of about 60 to 100 mm in diameter to a height of about 75 to 50 cm on the top and bottom, respectively.
In the lower chamber 2 at the bottom, water collection and backwash pipes 6 with water flow and ventilation holes 7 bored on both sides and the lower part, which have the function of collecting tertiary treated water and backwashing air, are installed horizontally. 5,5
An aeration pipe 16 is installed in the upper chamber 15 in the upper part of a, an air supply pipe 17 for aeration and an on-off valve 10 are connected to the aeration pipe 16, and a water supply pipe for tertiary treated water is connected to the water collection backwash pipe 6. 8 and an on-off valve 10, and a backwash air supply pipe 1 is connected to the water pipe 8 via an on-off valve 14.
3, and a backwashing water pipe 19 is installed through the on-off valve 20, and the backwashing air supply pipe 13 is connected to the backwashing supply pipe 13.
and the air diffuser supply pipe 17 are merged to form the blower B.
The backwash water pipe 19 is connected to a backwash tank 9.
Backwash water supply pump 21 that pumps up tertiary treated water
A cobblestone filtration device characterized in that a cleaning pipe 24 for pumping up sludge is vertically supported and connected to the upper chamber 15 and extends vertically from the upper chamber 15 to the lower chamber 2. 4 A sewage inlet pipe 1 and a backwash trough 22 for secondary treatment water are provided in the upper part of the tertiary treatment tank T, a rostre 4 is provided in the lower part of the tertiary tank T, and a suitable Cobblestones 5, 5a, and 5b on which airborne microorganisms can adhere and propagate are piled up in multiple tiers, and among them, a relatively large cobblestone 5 with a diameter of about 100 to 150 mm is placed on the lower side of the lower tier, and a relatively large cobblestone 5 with a diameter of about 60 to 100 mm is placed on the upper side. A medium-sized cobblestone 5b is placed in the upper part, and a relatively small cobblestone 5a with a diameter of about 30 to 60mm is placed in the upper and lower parts, respectively.
They are piled up about 75 to 50 cm, and the lower chamber 2 at the bottom of the rostle 4 has water passage and ventilation holes 7 on both sides and the lower part to collect water for tertiary treatment water and for air backwashing. The pipe 6 is installed horizontally, and the boulders 5, 5a, 5b
An aeration pipe 16 is connected to the upper chamber 15 in the upper part, and an air supply pipe 17 for aeration and an on-off valve 1 are connected to the aeration pipe 16.
0 is connected to the water collection backwash pipe 6, and a water flow pipe 8 for tertiary treated water and an on-off valve 10 are connected to the water collection backwash pipe 6, and a backwash air supply pipe 13 is connected to the water flow pipe 8 via an on-off valve 14.
In addition, a backwashing water pipe 19 is installed through the on-off valve 20, and the backwashing air supply pipe 13 and the aeration air supply pipe 17 are merged and connected to the blower B. A backwash water supply pump 21 for pumping up the tertiary treated water from the backwash tank 9 is connected to the backwash water pipe 19, and a cleaning pipe 24 for pumping up sludge that runs vertically from above the upper chamber 15 to the lower chamber 2 is connected to the backwash water pipe 19. A cobblestone filtering device characterized by being installed and supported.