JP4618737B2 - Road surface wastewater treatment tank - Google Patents

Description

  The present invention relates to a road surface drainage treatment tank that separates and removes sediment contained in road surface drainage installed in a side groove of a roadway.

  On the road surface of national roads and other motorways, earth and sand, dust, suspended substances in the air, particulate matter floating in the water, so-called SS, worn tires of automobile tires and paved asphalt, and vehicles in the event of an accident Various things such as pollutants such as fuel are deposited. These pollutants pass through drainage facilities from the road surface in rainy weather, and flow into public water areas such as rivers, lakes and coastal waters, or fields around rivers and lakes, and are one of the causes of water pollution. Yes.

  The pollutant deposited on the road surface flows out as road drainage mainly due to the initial rainwater at the time of rainfall, but it is usually said that there are three patterns in this road drainage depending on the state of rainfall.

  First, the first pattern is a case where precipitation with a certain rainfall intensity continues. In this case, the pollution concentration is high at the beginning of the rain. However, the pollution concentration converges 2 hours after the start of rainfall.

  The second pattern is a case where the initial rainfall is low and then the rainfall increases rapidly. In this case, the pollution concentration is high at the beginning of the rain and the pollution once decreases. However, when the rainfall intensity increases, the pollution rises again to a high concentration.

  The third pattern is when it rains or stops. In this case, the initial rainfall time is short and the amount of rainfall is the smallest, but the amount of rainfall increases during the next rainfall. In this case, since a certain amount of rainwater is required for the pollutant on the road surface to flow out, the pollutant concentration at the next rainfall is higher than the initial pollutant concentration.

  By the way, although there are the above three patterns, most of the road pollutant material flows out by the first flush water of the first or second pattern in the first two hours of the rain. Among them, the SS substance which is a particulate substance floating in the road surface drainage is the biggest cause of road pollution. Therefore, by selectively treating and purifying these first flush waters, it is possible to drastically reduce the load caused by pollutants in the road surface drainage.

  An apparatus for selectively storing only the first flush water of such road drainage and leading it to a purification tank has been developed. This is because a drainage trough is installed in the existing drainage basin installed in the side ditch on the roadway side, and a storage / purification basin is installed under the adjacent sidewalk. This removes not only the particulate matter of the SS substance but also the soluble substance showing the hardly decomposable COD. The filtered waste water is drained by a drain pipe at the bottom of the storage / purification tank, and returned to an existing drain pipe or penetrated underground (for example, see Non-Patent Document 1).

  In addition, rain that has fallen on the road surface is put into a side groove via the road surface, collected from the side groove into a settling tank beside the side groove to remove large debris, and then this wastewater is put into an adjacent processing tank. The wastewater is once dropped to the bottom, and the pollutant is removed by filtration by flowing upward in the filter medium of expanded polypropylene particles, and the purified wastewater is discharged from the adjacent drainage basin to the drainage groove on the roadway. Wastewater exceeding the treatment amount is discharged without being treated as overflow water to a drainage facility such as a gutter (see Non-Patent Document 2, for example).

  However, they are not necessarily excellent in measures against rain on urban roadways, and they do not correspond to urban heat island phenomenon or urban flood.

  Therefore, the inventors have temporarily stored and treated only the first flush water of the road surface drainage within 2 hours of the first flush at the beginning of the rain, and processed the soil and sand contained in the first flush water of the road surface drainage. Treatment that removes and purifies contaminants such as dust, suspended matter in the air, particulate matter floating in the water, so-called SS, wear debris from automobile tires and paving asphalt, and car fuel in the event of an accident Road surface where water is discharged or purified treated water is discharged into sewage, urban heat island phenomenon is alleviated by temporary storage, and is further laid in a gutter on the side of the roadway where automobiles are prepared for urban flooding A wastewater treatment tank has been developed (see, for example, Patent Document 1).

JP 2006-28843 A "FF Cleaner" Shiga Prefecture, Biwako and Yodogawa Water Safety Organization, Toray Engineering Co., Ltd., brochure "Road surface wastewater treatment system" Hokucon Co., Ltd., 2003/01/15, pamphlet

  The problem to be solved by the present invention is that only the first flush water of the road surface drainage within 2 hours of the first flush in the early stage of rain described above is temporarily stored and processed, and is contained in the first flush water of the road surface drainage. Remove dirt, dust, dust suspended in the air, particulate matter suspended in water, so-called SS, automobile tires and pavement asphalt wear debris, and car fuel in the event of an accident. In road surface wastewater treatment tanks that have the function of seeping purified water, it prevents re-stirring of contaminants associated with the tank structure in the road surface wastewater treatment tank, and further suppresses the momentum of the vortex generated by the inflowing water. It is to provide a road surface drainage treatment tank capable of preventing agitation of polluted substances precipitated at the bottom of the tank.

  The means of the present invention for solving the above-mentioned problem is that, in the invention of claim 1, the upper surface lid 5 connected to the side groove 2 on the roadway side and having the upper surface 2c of the side groove 2 as the surface height, and the upstream side groove 2 An inflow port 10a for inflowing road surface drainage, an outlet 10b for discharging the inflowed road surface drainage from the overflow passage 14 at a position lower than the bottom surface 3 of the side groove 2 to the downstream side groove 2, and lower than the bottom surface 3 of the side groove 2 The bottom wall 9a, 9b of the upstream inflow portion 6a of the road surface drainage and the downstream inflow portion 6b having the bottom port 7a and the bottom port 7b, respectively, and lower than the inflow port 10a and the discharge port 10b. And an outflow path 11a to a sewer pipe crossing under the overflow passage 14 via a weir 11c higher than the outflow path 11a on the opposite side, and a flow to the underground storage tank 13 extending at a lower level to the opposite side of the outflow path 11a. Forming the upper tank 4 provided with a central opening 12 of the central opening of the bottom wall and a road 11b. Further, a lower tank 15 made of a circular tank is formed below the upper tank 4. Therefore, the lower tank 15 has an outlet 8a and an outlet 8b on the lower surface of the ceiling wall 16 communicating with the ceiling wall 16 of the lower tank 15 which is the bottom wall of the upper tank 4 and the bottom port 7a and the bottom port 7b of the upper tank 4. An outlet 19 opening in the center of the ceiling wall 16 that is the central opening 12 of the bottom wall, and an outer center cone 20 that expands from the outlet 19 of the lower tank 15 to the bottom of the tank and expands in a flared shape, The outer center cone 20 has an inner center cone 21 which is spaced apart from the inside of the outer center cone 20 and has a circular opening at the upper center of the outer center cone 20 and expands in a flared shape toward the lower portion of the lower tank 15. And a vortex flow control plate 22 composed of a plurality of standing plates that are arranged in a spiral between the circular lower ends of the inner center cone 21 and are spaced apart at equal intervals, and the contamination contained in the road surface drainage. Sediment storage It is formed from the bottom wall 18 of the lower tank 15, 17. Thus, the road surface wastewater treatment tank 1 according to the means of claim 1 is formed from the above structure.

In the invention of claim 2, the road surface drainage treatment tank 1 is formed from a concrete block 23, and an upper cover concrete block 26 that forms an upper cover 5 disposed on the upper part of the upper tank 4 and an upper concrete block that forms the upper tank 4. 25 and a lower concrete block 24 that forms a lower tub 15 disposed below the upper concrete block 25. The upper concrete block 25 is loaded on the lower concrete block 24 and connected to each other. The outer center cone 20 and the inner center cone 21 are formed of a stainless steel plate or an FRP plate, and the eddy current control plate 22 is formed of a plurality of spiral standing plates that support and connect the outer center cone 20 and the inner center cone 21 at the lower part. It is made of stainless steel plate or FRP plate A road wastewater treatment tank 1 means according to claim 1,.

  The present invention embeds a road surface drainage treatment tank having a lower tank connected to a side groove on the roadway side under a sidewalk beside the roadway, and causes the road surface drainage due to rainfall to flow into a lower tank that is a catchment basin, Such as earth and sand, dust, suspended solids in the air, particulate matter suspended in rainwater, tire and paving asphalt wear debris, car fuel in the event of an accident, etc. The pollutant is swirled together with the road surface drainage in the lower tank to separate and remove it as a precipitated substance, and the road surface drainage that has become lighter by removing the precipitated substance is temporarily stored from the upper tank to the adjacent underground storage tank, while the road surface drainage If the adjacent underground storage tank is full while the drainage is below the allowable inflow of the treatment tank, this excess treated water will flow over the weir of the outflow path and will flow into the sewer pipe, In addition to purification, the city uses treated water from temporary storage. It is possible to take measures against heat islands and urban floods. In addition, road drainage generated from rainfall exceeding the allowable inflow amount of the road surface drainage treatment tank is bypassed by the overflow passage without passing through the lower tank and allowed to flow into the downstream side ditch. In addition, the present invention is a road surface drainage treatment tank that exhibits excellent effects, such as enabling accurate separation and removal of road surface contaminants contained in the first flush water at the beginning of rainfall.

  Furthermore, the road surface wastewater treatment tank of the present invention has an inner center cone arranged in a similar shape inside the outer center cone, and a vortex control plate is provided at the lower end of these center cones, so that the vortex flow is not disturbed for a long time. By suppressing the re-stirring of the pollutant in the tank to enhance the sedimentation effect, and further dividing the road surface drainage treatment tank from the concrete block, the shape is simplified and the molding becomes easy, In addition, it is easy to transport by dividing into each block and downsizing, and handling at the time of laying on the site is facilitated. Further, the outer center cone, the inner center cone and the eddy current control plate are made of stainless steel plate or FRP plate. By reducing the thickness of these structures and occupying the processing tank, the efficiency of the tank is increased, and the structure is resistant to strength and corrosion resistance. Such as increasing the gender, the present invention has excellent effects.

  The best mode for carrying out the present invention will be described below with reference to the drawings. 1 to 4 show a road surface wastewater treatment tank 1 according to an embodiment of the present invention. The road surface drainage treatment tank 1 of the present invention is laid in the basement of a side groove 2 on the side of a roadway having a sidewalk in an urban area where a national road and other automobiles travel and is connected to the side groove 2. The road surface wastewater treatment tank 1 is formed of a rigid and durable material, but is generally formed of a concrete block 23. That is, it is formed from a lower concrete block 24 constituting the lower tank 15 of the road surface drainage treatment tank 1, an upper concrete block 25 constituting the upper tank 4, and an upper cover concrete block 26 constituting the lid of the upper tank 4. In this case, the upper surface lid 5 of the upper tub 4 composed of the upper surface lid concrete block 26 is installed at a height position of the upper surface 2 c of the side groove 2. The road surface wastewater treatment tank 1 receives the road surface wastewater from the upstream side groove 2a. By the way, the upper cover concrete block 26 has a grating 27 fitted therein, and the road surface drainage flowing on the sidewalk is directly received from the grating 27 into the inflow portion 6 in the upper tank 4. Further, the inflow portion 6 of the upper tank 4 has a bottom opening that opens at a position lower than the bottom surface 3 of the side groove 2. That is, the upper tank 4 integrally has a bottom wall 9a and a bottom wall 9b that open the bottom port 7a of the inflow portion 6a on the upstream side of the road surface drainage and the bottom port 7b of the inflow portion 6b on the downstream side of the road surface drainage.

  Further, the upper tank 4 has an inflow port 10a through which the road surface drainage flows from the upstream side groove 2, and the inflow road surface drainage is at the same height as the bottom surface 3 of the side groove 2 without passing through the lower tank 15 and the bottom wall. There is a discharge port 10b that discharges from the overflow passage 14 passing above to the side groove 2 on the downstream side. On the other hand, the upper tank 4 has an opening center port 12 at the center of the bottom wall, and has an outflow path starting from the center port 12. This outflow channel is an outflow channel 11a, one side of which is lower than the inflow port 10a and the discharge port 10b, crosses the weir 11c higher than the outflow channel, crosses under the overflow channel 14 at a right angle, and leads to a sewer pipe buried in the roadway. And the other side is an outflow path 11b including a bottom wall 9c extending to the opposite side of the outflow path 11a and leading to the underground storage tank 13. The highest height position of the bottom wall 9c is the position of the constant water surface of the road surface wastewater treatment tank 1, and the upper tank 4 has these configurations.

  A lower tank 15 made of a circular tank is integrated and arranged at the lower part of the upper tank 4, and the bottom wall of the upper tank 4 forms a ceiling wall 16 of the lower tank 15. On the lower surface of the ceiling wall 16, there are an outlet 8 a and an outlet 8 b communicating from the bottom port 7 a and the bottom port 7 b of the upper tank 4. The outlet 8a and the outlet 8b are formed of an L-shaped elbow such as a polyvinyl chloride pipe. The outlet 8a and the outlet 8b are each directed in a counterclockwise direction concentric with the circle of the circular tank. Furthermore, an opening 19 is provided on the lower surface of the ceiling wall 16 at the center of the ceiling wall 16 communicating with the central port 12 of the bottom wall of the upper tank 4. An outer center cone 20 is connected to the outlet 19 from the lower tank 15 through a central circular opening 20a and extends from the circular opening 20a to the lower portion of the lower tank 15 so as to expand in a flared manner. Further, inside the outer center cone 20, it is separated from the outer center cone 20 and is connected by a central circular opening 21 a, and the inner center cone 21 is concentrically expanded to expand toward the lower portion of the lower tank 15. Have Between the circular lower end of the outer center cone 20 and the circular lower end of the inner center cone 21, there are a plurality of perforated plates, for example, eight, which are arranged in a spiral shape spaced apart at equal intervals. It has a vortex control plate 22 and supports the inner center cone 21 from its lower end. Further, the bottom wall 18 of the lower tank 15 serves as a sediment reservoir 17 for pollutants contained in the road surface drainage. On the other hand, the deposit in the deposit storage part 17 on the bottom wall 18 of the lower tank 15 is periodically sucked and removed by inserting a suction pipe of a vacuum car for maintenance management.

  Next, the operation of the road surface wastewater treatment tank 1 of the present invention will be described. In the road surface wastewater treatment tank 1, an inflow port 10a of the upstream inflow portion 6a is disposed in the upstream side groove 2a. The road surface drainage that flows from the upstream side groove 2a flows into the lower tank 15 from the outlet 8a of the ceiling wall 16 into the bottom port 7a of the inflow portion 6a. On the other hand, when the road surface drainage flowing into the upper tank 4 exceeds the allowable inflow amount of the lower tank 15, the road surface drainage that cannot enter the lower tank 15 flows out through the overflow passage 14 at the upper part of the upstream inflow portion 6a. If it flows out to the passage 11a and still cannot flow out, it is discharged from the discharge port 10b to the downstream side groove 2b without being processed.

  Further, the road surface drainage flowing on the sidewalk is received directly from the grating 27 of the top cover 5 into the upstream inflow portion 6a and the downstream inflow portion 6b of the upper tank 4, and from the bottom port 7a and the bottom port 7b to the lower tank 15 It flows out into the lower tank 15 from the outlet 8a and the outlet 8b of the ceiling wall 16. The road surface drainage that has flowed out of the outlet 8a and the outlet 8b of the ceiling wall 16 in this way falls on the wall surface of the outer center cone 20 that spreads out, and in the northern hemisphere of the earth, while turning counterclockwise due to the rotation of the earth. Drops to the bottom of the tank over time. During this time, the pollutants contained in the road surface drainage are separated by specific gravity and settled on the bottom wall 18 of the lower tank 15. In this case, the treated water after removing the pollutant in the road surface drainage is swirled gently by the vortex control plate 22 having a small hole attached to the lower end of the outer center cone 20 on the front surface. Thus, the once polluted contaminants are prevented from being re-stirred. In this way, the road surface drainage removes pollutants and becomes light treated water, enters the inside of the outer center cone 20, and floats up between the outer center cone 20 and the inner center cone 21 and from the inner side of the inner center cone 21. To do. The treated water that has floated in the lower tank 15 flows into the upper tank 4 from the outlet 19 at the center of the ceiling wall 16 of the lower tank 15 and from the central port 12 on the bottom wall of the upper tank 4. The treated water that has flowed into the upper tank 4 from the central port 12 on the bottom wall of the upper tank 4 is discharged from the outflow path to the outside of the road surface wastewater treatment tank 1. In this case, when the inflow amount of the road surface drainage treatment tank 1 is an allowable inflow amount of, for example, 1.0 liter / sec or less, the treatment processed in the lower tank 15 and discharged from the central port 12 to the upper tank 4. The water flows into the underground storage tank 13 installed adjacent to the road surface wastewater treatment tank 1 via the right outlet channel 11b in FIG. 4, for example, in the basement of the sidewalk, and is stored for reuse.

  On the other hand, even if the inflow rate is less than the allowable inflow rate of, for example, 1.0 liter / sec or less, if the underground storage tank 13 is already filled with treated water, The treated water discharged from 12 to the upper tank 4 passes over the left weir 11 c in FIG. 4, flows through the outflow path 11 a, and is discharged to a sewage pipe (not shown) outside the tank of the road surface wastewater treatment tank 1.

  In the embodiment of the present invention, the housing of the road surface drainage treatment tank 1 is formed from the concrete block 23 as described above. That is, it is formed of the lower tub 15 of the lower concrete block 24, the upper tub 4 of the upper concrete block 25, and the upper cover concrete block 26. As described above, the concrete block 23 according to the present invention can be manufactured by being divided into the top cover concrete block 26, the upper concrete block 25, and the lower concrete block 24, respectively. Thus, it has the advantage of being simplified and easy to manufacture. That is, since the shape is simplified, the concrete block 23 of the present invention is easy to mold. Furthermore, since the lower concrete block 24, the upper concrete block 25, and the upper cover concrete block 26 are divided, the size of each of the lower concrete block 24, the upper concrete block 25, and the upper cover concrete block 26 can be reduced. For example, it becomes easy to carry to the site or to lay on site. Furthermore, the lower concrete 24 can be divided into left and right in the vertical direction at the center of FIG. Of course, it goes without saying that the road surface drainage treatment tank 1 according to the means of claim 1 can be formed from a material having sufficient rigidity and durability, such as a material other than these concrete blocks, such as cast iron.

It is a perspective view which decomposes | disassembles and shows the waterway of a side groove | channel, and the road surface wastewater-treatment tank of this invention juxtaposed to this waterway. It is a top view of the road surface wastewater treatment tank of embodiment of this invention, and is AA arrow line view of FIG. It is a front longitudinal cross-sectional view of the road surface wastewater treatment tank of embodiment of this invention, and is a BB arrow line view of FIG. 1. It is a side longitudinal cross-sectional view of the road surface wastewater treatment tank of embodiment of this invention, and is CC arrow line view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Road surface wastewater treatment tank 2 Side groove 2a Upstream side groove 2b Downstream side groove 2c Upper surface 3 Bottom surface (of side groove)
4 Upper tank 5 Top cover 6a Inflow part (upstream side)
6b Inflow part (downstream side)
7a Bottom port 7b Bottom port 8 Exit (from ceiling wall to lower tank)
8a outlet 8b outlet 9a bottom wall 9b bottom wall 9c bottom wall 10a inflow port 10b outlet port 11a outflow channel 11b outflow channel 11c weir 12 central port (of upper tank)
13 underground storage tank 14 overflow passage 15 lower tank 16 ceiling wall 17 sediment storage part 18 bottom wall (of lower tank)
19 Outlet (ceiling wall)
20 outer center cone 20a circular opening 21 inner center cone 21a circular opening 22 eddy current control plate 23 concrete block 24 lower concrete block 25 upper concrete block 26 top cover concrete block 27 grating

Claims (2)

An upper surface lid (5) connected to the side groove (2) on the roadway side and having the upper surface (2c) of the side groove (2) as a surface height; an inlet (10a) for inflowing road surface drainage from the upstream side groove (2); A discharge port (10b) for discharging the inflow road surface drainage from the overflow passage (14) at a position lower than the bottom surface (3) of the side groove (2) to the downstream side groove (2), and the bottom surface of the side groove (2) (3) Each bottom wall of the inflow portion (6a) on the upstream side of the road surface drainage and the inflow portion (6b) on the downstream side of the road surface drainage, each having a bottom port (7a) and a bottom port (7b) that open to lower positions ( 9a), (9b), and a sewage pipe crossing under the overflow passage (14) via a weir (11c) lower than the inlet (10a) and outlet (10b) and higher than the opposite outlet (11b) Outflow channel (11a) to the opposite side of the outflow channel (11a) An upper tank (4) provided with a central opening (12) of an opening is formed at the center of the bottom wall (9c) having the outflow path (11b) to the underground storage tank (13), and the upper tank (4). The lower tank (15) which consists of a circular tank is formed in the lower part of this, the ceiling wall (16) of the lower tank (15) which is a bottom wall of the upper tank (4), and the bottom port (7a) of the upper tank (4) And an outlet (8a) and an outlet (8b) on the lower surface of the ceiling wall (16) communicating with the bottom opening (7b), and an outlet at the center of the ceiling wall (16) which is the central opening (12) of the bottom wall (19), an outer center cone (20) that expands from the outlet (19) of the lower tank (15) to the lower part of the tank, and the inner center of the outer center cone (20). An inner center core having a circular opening (21a) at the center upper portion and expanding in a flared shape toward the bottom of the lower tank (1). (21) and arranged in a spiral between the circular lower end of the outer center cone (20) and the circular lower end of the inner center cone (21) at an equal interval so that the inner center cone (21) is disposed from the lower end. A vortex flow control plate (22) comprising a plurality of standing plates to be supported and a bottom wall (18) of a lower tank (15) serving as a sediment reservoir (17) for contaminants contained in road drainage. Road surface wastewater treatment tank (1) . The road surface drainage treatment tank (1) is formed from a concrete block (23), and includes an upper cover concrete block (26) that forms an upper cover (5) disposed on the upper part of the upper tank (4), and an upper tank (4). An upper concrete block (25) to be formed and a lower concrete block (24) forming a lower tub (15) disposed below the upper concrete block (25) are formed, and the upper concrete block (24) The concrete block (25) is loaded and connected to each other, the outer center cone (20) and the inner center cone (21) in the lower tank (15) are formed from a stainless steel plate or FRP plate, and the outer center cone (20) And an eddy current control plate (22) comprising a plurality of spiral standing plates for supporting and connecting the inner center cone (21) at the lower part. Road wastewater treatment tank according to claim 1, wherein it is formed from a stainless plate or FRP plate (1).

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