Wastewater treatment apparatus

Abstract

To provide a wastewater treatment apparatus that enables continuation of treatment of water to be treated in the case where the inflow speed of the water to be treated is greater than a predetermined quantity.SOLUTION: A wastewater treatment apparatus 10 configured to collect plastic capsules contained in paddy field drainage as the water to be treated, the wastewater treatment apparatus including: a base body 13 provided with a tubular wall portion 13A defining a portion of a flow channel in which the water to be treated flows; a first member 11 disposed inside the wall portion 13A and provided with a first filtering portion crossing the flow channel; and a tubular second member 12 equipped with a second filtering portion 12A that extends upstream from the upstream end of the wall portion 13A.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a wastewater treatment device for collecting plastic capsules contained in paddy field wastewater. [Background technology]

[0002] Currently, coated fertilizers, in which fertilizer ingredients are covered in plastic capsules, are widely used in rice cultivation, but in recent years, there has been international discussion about the outflow of plastic waste into the natural environment. It has been pointed out that plastic from coated fertilizers accounts for 15% of the plastic waste that is released into the natural environment. Therefore, there is a need to collect plastic capsules contained in paddy field drainage.

[0003] Patent Document 1 listed below discloses a drainage device equipped with a dust removal filter at a drainage inlet. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2015-137486 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the drainage device described in Patent Document 1, for example, if the wastewater contains a large amount of impurities such as plastic capsules, the impurities may adhere to the debris removal filter and cause clogging, which could cause the flow rate of the wastewater into the drainage device to exceed the filtration rate of the debris removal filter, making it impossible to treat the wastewater.

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a wastewater treatment device that can continue treating the water to be treated even when the inflow rate of the water to be treated exceeds the treatment rate. [Means for solving the problem]

[0007] In order to achieve the above object, the wastewater treatment device of the present invention comprises: A wastewater treatment device for collecting plastic capsules contained in paddy field wastewater, which is water to be treated, a base body having a cylindrical wall portion defining a part of a flow path through which the water to be treated flows; a first member having a first filtration portion that intersects the flow path inside the wall portion; The second cylindrical member has a second filtering portion extending upstream from the upstream end of the wall portion.

[0008] According to the wastewater treatment device of the present invention, even if the first filtration section becomes clogged due to the adhesion of contaminants such as plastic capsules, the treatment of the water can be continued by discharging the water from the second filtration section. Furthermore, when the water is discharged from the second filtration section, an irregular water flow (also called a circulating flow, turbulent flow, sweeping flow, etc.) of the water to be treated occurs inside the wastewater treatment device, which provides a self-cleaning effect that removes contaminants that once adhered to the first filtration section.

[0009] In the wastewater treatment device having the above configuration, a cylindrical funnel member that defines a portion of the flow path upstream of the wall portion and has a tapered portion that gradually reduces in diameter from the upstream side to the downstream side, It is preferable that the upstream end of the second member is connected to the outer surface of the funnel member at the tapered portion or at a portion upstream of the tapered portion.

[0010] In a wastewater treatment device having this configuration, if the water being treated contains large obstacles, such as straw, the obstacles get caught on the inner surface of the tapered section. This prevents the obstacles from flowing into the wall and eventually reaching the first and second filtration sections, which could cause clogging of the first and second filtration sections. Furthermore, impurities that cannot pass through the second filtration section accumulate from the upstream side in the space between the second filtration section and the outer surface of the tapered section, preventing the impurities from flowing back upstream (inside the funnel member).

[0011] In the wastewater treatment device having the above configuration, It is preferable to include a third member having a third filtering portion that covers the second filtering portion.

[0012] According to the wastewater treatment device having this configuration, even if impurities pass through the second filtration section, the impurities can be collected by the third member, thereby more reliably preventing the impurities from flowing out of the wastewater treatment device.

[0013] In the wastewater treatment device having the above configuration, The first filtering section is preferably formed of a porous body.

[0014] According to the wastewater treatment device having this configuration, the water to be treated is subjected to depth filtration through the porous body, thereby making it possible to prevent clogging of the first filtration section.

[0015] In the wastewater treatment device having the above configuration, The first filtering section is preferably formed of a surface filtering member.

[0016] According to the wastewater treatment device having this configuration, the self-cleaning action of the first filtering member by the water to be treated can be more effectively achieved. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a side view showing an embodiment of a wastewater treatment device according to the present invention. [Figure 2] FIG. 2 is an enlarged view showing an embodiment of a funnel member and a second filtration section according to the present invention. [Figure 3] 1 is a plan view of an embodiment of a wastewater treatment device according to the present invention, as viewed from above. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of a wastewater treatment device according to the present invention will be described with reference to the drawings.

[0019] 1 shows one embodiment of a wastewater treatment device according to the present invention. The wastewater treatment device 10 includes a funnel element 14 that defines a portion of the flow path for paddy field wastewater, which is the water to be treated, and a base 13 having a cylindrical wall 13A that defines a portion of the flow path downstream of the funnel element 14. In other words, the water to be treated that flows into the wastewater treatment device 10 passes through the inside of the funnel element 14 and then through the inside of the base 13. During this operation, impurities such as obstacles 20 and plastic capsules 30 contained in the water to be treated are captured by the wastewater treatment device 10.

[0020] In this embodiment, the base 13 is cylindrical, but the shape is not particularly limited, and may be, for example, a polygonal cylindrical shape with a cross section that is triangular, square, or the like. The size is also not particularly limited, and can be designed appropriately depending on the flow rate of the water to be treated, the installation location, the amount of impurities such as plastic capsules, etc., but in the case of a cylindrical shape, for example, the diameter can be about 20 cm and the height can be about 40 cm.

[0021] The dotted arrows shown in Figures 1 and 2 indicate an example of the water flow of the water to be treated flowing inside the wastewater treatment device 10. The funnel member 14 and the base 13 are spaced apart. In this embodiment, impurities such as plastic capsules 30 are basically collected in the space surrounded by the second member 12, the funnel member 14, and the first member 11. The amount of plastic capsules 30 present is often about 5-10% by weight of all impurities including the plastic capsules 30 after drying, but the present invention can be used regardless of this ratio.

[0022] The wastewater treatment device 10 includes a first member 11 having a first filtration section that intersects with the flow path of the water to be treated inside a wall portion 13A, a cylindrical second member 12 having a second filtration section 12A that extends upstream from the upstream end of the wall portion 13A, and a third member 15 that covers the second filtration section 12A.

[0023] The first member 11 is formed over the entire interior area of the wall portion 13A in the horizontal direction, which is the cross-sectional direction of the flow path. Therefore, the water to be treated that has flowed into the interior of the wall portion 13A comes into contact with the first member 11 and is filtered by the first filtration portion. The first filtration portion does not have to be formed over the entire area of the first member 11, as long as it can perform its intended function. As an example, when the base 13 is cylindrical and has a diameter of 20 cm, and porous concrete, which will be described later, is used as the first filtration portion, the area of the first filtration portion is 80 to 300 cm. 2 The thickness of the first filtration section can be set to, for example, about 2 to 3 cm. In other words, the volume of the first filtration section can be set to 160 to 900 cm. 3 It can be set to a certain extent.

[0024] In this embodiment, the first member 11 is formed in the horizontal direction, but the first member 11 may be formed in a direction inclined relative to the horizontal direction as long as it is formed over the entire interior area of the wall portion 13A.

[0025] The first filtration section is made of porous concrete. Therefore, the water to be treated can be deep filtered using the porous concrete. Here, deep filtration is a filtration method in which the water to be treated is filtered by capturing particles in gaps formed inside the filtration section (membrane), and is also known as internal filtration. In addition, porous concrete has the function of capturing heavy metals, and by using porous concrete in the first filtration section, not only can it collect impurities such as plastic capsules, but it can also purify the water to be treated.

[0026] In this embodiment, the first filtration section is formed of porous concrete, but a porous material other than porous concrete or a surface filtration member may be used. Here, the surface filtration member is a member used for surface filtration, which is a filtration method in which particles are captured on the surface of the filtration section to filter the water to be treated.

[0027] Porous bodies other than porous concrete can be made of sintered resin materials such as polyethylene or polypropylene. The surface filtration member can be a mesh-like member made of wires made of metal such as stainless steel arranged in a lattice pattern, or a member made of a metal plate such as stainless steel with openings that allow the water to pass through.

[0028] The first filtration section preferably uses a porous body containing large voids. When using porous concrete, for example, as the first filtration section, adjusting the maximum aggregate diameter according to the environment and circumstances can result in a porous body containing large voids, thereby suppressing clogging and improving the filtration efficiency of the water being treated. The maximum aggregate diameter can be determined by selecting the type of single-grain crushed stone to be used and then adjusting the grain size. While this depends on the environment and circumstances, it is generally preferable to use No. 6 crushed stone with a maximum diameter adjusted to 10 mm or less as the first filtration section. If the particle size of the aggregate used is too large, the diameter of the voids contained in the porous body will be too large. For example, if the porous body is porous concrete, the filtration efficiency of the water being treated tends to be weakened.

[0029] Furthermore, when it is important to more effectively achieve the self-cleaning effect of removing impurities that have adhered to the first filtration section, as described below, it is desirable to install the first filtration section in a position where it can be washed by the circulating flow inside the cylinder, and in that case to use a porous body with a pore size that allows impurities that have adhered to the surface to be easily removed by the sweep flow.

[0030] The second member 12 is formed in a cylindrical shape. The upstream end of the second member 12 abuts against the funnel member 14, and the downstream end of the second member 12 abuts against the first member 11. Therefore, the second member 12 supports the funnel member 14, which is separated from the base 13, from below.

[0031] A portion (downstream side) of the second member 12 is provided inside the wall portion 13A so as to abut against the inner surface of the wall portion 13A. The second member 12 also has a second filtration portion 12A that extends upstream of the upstream end of the wall portion 13A.

[0032] Therefore, when the amount of water to be treated is greater than the capacity of the space defined by the first member 11 and the wall portion 13A, a portion of the water to be treated is filtered by the second filtration portion 12A and discharged outside the wastewater treatment device 10.

[0033] Therefore, even if the inflow rate of the water to be treated into the wastewater treatment device 10 exceeds the filtration rate by the first filtration section, the wastewater treatment device 10 can continue to properly treat the water to be treated.

[0034] Possible reasons for the inflow rate of the water to be treated into the wastewater treatment device 10 exceeding the filtration rate by the first filtration section include simply a large amount of inflow water, as well as a decrease in filtration performance due to clogging of the first filtration section.

[0035] If a portion of the water to be treated is filtered by the second filtration section 12A and discharged outside the wastewater treatment device 10 due to a decrease in filtration performance caused by clogging of the first filtration section, the wastewater treatment device 10 can obtain a self-cleaning effect using the water to be treated.

[0036] Specifically, the water to be treated that has flowed into the interior of the wall portion 13A first comes into contact with the first member 11. Thereafter, the water to be treated that has not passed through the first filtration section of the first member 11 changes course upstream along the wall portion 13A in order to flow out of the wastewater treatment device 10 from the second filtration section. Such an irregular water flow of the water to be treated occurs on the surface of the first member 11, thereby achieving a self-cleaning effect that peels off impurities that have once adhered to the first filtration section.

[0037] In this embodiment, the second member 12 is formed in a cylindrical shape, but the shape of the second member 12 may be a polygonal tube shape such as a triangular or rectangular cross section. The second member 12 need only have the second filtration section 12A extending from the upstream end of the wall section 13A, and need not be provided inside the wall section 13A. In this embodiment, the second member 12 and the base 13 are provided separately, but the second filtration section may be provided as part of the base 13 as long as it extends upstream of the upstream end of the wall section 13A.

[0038] The second filtration section 12A is formed of a mesh member in which stainless steel wires are arranged in a lattice pattern, so that the water to be treated is filtered by the mesh arranged in a lattice pattern and flows out of the wastewater treatment device 10.

[0039] In this embodiment, the second filtration section 12A is formed of a mesh-like member in which stainless steel wires are arranged in a grid pattern, but it is also possible to use, for example, a mesh-like member in which wires made of a metal other than stainless steel are arranged in a grid pattern, or a member in which a plate made of a metal such as stainless steel is provided with openings that allow the water to be treated to pass through. Furthermore, the second filtration section 12A is not limited to metal and can be made of other materials such as resin as long as it can maintain its independence even when the water to be treated flows in.

[0040] The base 13 has a cylindrical wall portion 13A and a base 13B that supports the entire wastewater treatment device 10 by being placed on the ground. In this embodiment, the base 13B is provided, but it may be omitted depending on the installation location and usage mode of the wastewater treatment device 10. In that case, the discharge port 13C described below may not be necessary. In addition, the wall portion 13A is formed downstream of the location where the first member 11 is disposed with a discharge port 13C for discharging the untreated water filtered by the first filtration section to the outside of the wastewater treatment device 10.

[0041] In this embodiment, the wall 13A is formed in a cylindrical shape, but the shape of the wall 13A may be a polygonal prism such as a triangle or a square in cross section. In addition, in this embodiment, the discharge outlet 13C is formed in the wall 13A, but it may be formed in the base 13B. Furthermore, although there are differences depending on the paddy field, the type of fertilization, etc., plastic capsules often have a lighter specific gravity than water in terms of weight ratio (i.e., the specific gravity of a plastic capsule is 0.7 to 0.8 g / cm 3 Therefore, depending on the conditions of use of this embodiment, the plastic capsules may collect directly below the funnel member 14, or may collect above the first member depending on the time elapsed since the inflow of the water to be treated stopped. The location of the discharge outlet 13C can be set appropriately depending on such usage. From the viewpoint of improving the collection rate of plastic capsules, it is preferable to install the discharge outlet 13C downstream of the first member.

[0042] If the base 13 has a diameter of approximately 20 cm and a height of approximately 40 cm, and porous concrete is used for the first filtration section, for example, the vertical height of the second filtration section 12A can be approximately 15 cm, the vertical height of the entire second member including the second filtration section 12A can be approximately 37 cm, and the vertical height from the base 13B to the first member can be approximately 20 cm.

[0043] Fig. 2 is an enlarged view of the funnel element 14 and the second filtration section 12A, and Fig. 3 is a plan view of the wastewater treatment device 10 as viewed from above. As shown in Fig. 2 and Fig. 3, the funnel element 14 is formed in a cylindrical shape and has, from the upstream side of the water to be treated, an expanded diameter section 14A, a tapered section 14B, and a reduced diameter section 14C.

[0044] In this embodiment, the funnel member 14 is formed in a cylindrical shape, but the shape of the funnel member 14 may be a polygonal prism having a cross section that is triangular, rectangular, or the like.

[0045] An inlet is formed at the upstream end of the expanded diameter section 14A for allowing the water to be treated to flow into the wastewater treatment device 10. An outlet is formed at the downstream end of the reduced diameter section 14C for allowing the water to flow out of the funnel member 14. Therefore, the water to be treated that flows into the funnel member 14 passes through the expanded diameter section 14A, tapered section 14B, and reduced diameter section 14C in this order, and flows into the interior of the wall section 13A.

[0046] Tapered portion 14B is formed so that the diameter gradually decreases from enlarged diameter portion 14A toward reduced diameter portion 14C. In other words, tapered portion 14B is formed so that the diameter gradually decreases from the upstream side to the downstream side of the flow path for the water to be treated.

[0047] Therefore, when the water to be treated contains obstacles 20, such as straw, that are larger than the radial dimension of reduced diameter section 14C, the obstacles 20 get caught on the inner surface of tapered section 14B. This prevents obstacles 20 from flowing into wall section 13A, and ultimately prevents obstacles 20 from reaching the first and second filtration sections and clogging them.

[0048] Furthermore, because tapered portion 14B is formed so that the diameter gradually decreases from the upstream side to the downstream side of the flow path for the water to be treated, obstacles 20 are caught on the inner surface of tapered portion 14B in stages in order of size in the axial direction of the flow path, which makes it possible to prevent obstacles 20 from clogging the flow path.

[0049] Furthermore, since the tapered portion 14B is formed so as to gradually decrease in diameter from the upstream side to the downstream side of the flow path of the water to be treated, and the second filtration portion 12A is connected to the tapered portion 14B, plastic capsules 30 that have not been able to pass through the second filtration portion 12A accumulate from the upstream side in the space between the outer surface of the tapered portion 14B and the second filtration portion 12A.

[0050] In other words, the plastic capsules 30 that were unable to pass through the second filtration section 12A are collected upstream of the outlet of the funnel member 14, thereby preventing the plastic capsules 30 from flowing back into the interior (upstream side) of the funnel member 14.

[0051] In particular, impurities such as plastic capsules 30, which have a specific gravity lighter than that of water, are more reliably collected in the space between the outer surface of the tapered portion 14B and the second filtration portion 12A, and are prevented from leaking out of the space.

[0052] In this embodiment, the second filtering section 12A is connected to the tapered section 14B, but the second filtering section 12A may be connected to the expanded diameter section 14A or the reduced diameter section 14C.

[0053] The third member 15 has a third filtration section, which is a net made of threads woven in a lattice pattern. The third filtration section is provided so as to cover the entire second filtration section 12A from the outside. Therefore, even if impurities pass through the second filtration section 12A, the impurities can be collected by the third filtration section. In other words, the reliability of the wastewater treatment device 10 can be improved.

[0054] The threads of the third filtering section may be made of, for example, nylon, polyester, polyethylene, or the like.

[0055] As described above in detail, it is possible to provide a wastewater treatment device that can continue treating the water to be treated even when the inflow rate of the water to be treated exceeds a predetermined amount. Furthermore, the embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. Various omissions, substitutions, and modifications may be made as long as they are consistent with the spirit of the present invention. [Explanation of symbols]

[0056] 10 Wastewater treatment equipment 11 First member 12 Second member 13 Base 14 Funnel parts 15 Third member 20 Obstacles 30 plastic capsules

Claims

1. A wastewater treatment device for collecting plastic capsules contained in paddy field wastewater, which is water to be treated, a base body having a cylindrical wall portion defining a part of a flow path through which the water to be treated flows; a first member having a first filtering portion that intersects the flow path inside the wall portion; A wastewater treatment device comprising a cylindrical second member having a second filtration section extending upstream from the upstream end of the wall section.

2. a cylindrical funnel member that defines a portion of the flow path upstream of the wall portion and has a tapered portion that gradually reduces in diameter from the upstream side to the downstream side, The wastewater treatment device according to claim 1 , wherein an upstream end of the second member is connected to the outer surface of the funnel member at the tapered portion or at a portion upstream of the tapered portion.

3. The wastewater treatment device according to claim 1 , further comprising a third member having a third filtration section that covers the second filtration section.

4. 2. The wastewater treatment device according to claim 1, wherein the first filtration section is formed of a porous material.

5. 2. The wastewater treatment device according to claim 1, wherein the first filtration section is formed of a surface filtration member.

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