JP3878186B2 - Waste water treatment equipment - Google Patents

Description

  The present invention belongs to the technical field of reprocessing organic wastewater after treatment in a combined treatment septic tank, which is an incidental facility such as a general house, apartment house, or store, and in particular, a piece of wood reduced in a chip shape as a treatment medium The present invention relates to a waste water treatment apparatus that uses and decomposes.

  Miscellaneous wastewater and sewage discharged from ordinary houses, apartment houses, stores, etc., when these dwellings are not connected to public sewers, are sent to the merger treatment septic tank and processed according to the BOD. : (Biological oxygen demand: one of the indicators indicating the degree of water contamination) Discharged into rivers, ditches, etc. as organic wastewater of 20 mg / l or less.

  In areas where there are no rivers or ditches for discharging such organic wastewater, the organic wastewater was permeated into the ground as it was after treatment in the combined treatment septic tank. However, in recent years, from the viewpoint of environmental consideration, it is desired that this organic wastewater is further purified to a level close to rainwater of about 10 mg / l BOD and then permeated into the ground.

  Conventionally, such wastewater treatment methods include laminating and filling wood powder and wood chips (so-called sawdust) into a treatment tank embedded in a space excavated from the ground surface, and spraying treated wastewater into this laminate In addition, water is added to water (hereinafter referred to as “injection”), and biodegradation treatment is performed using microorganisms that inhabit wood chips (see, for example, Patent Document 1).

As shown in FIG. 3, the wastewater treatment method disclosed in Patent Document 1 adds treated wastewater through a water injection pipe p having a large number of water-permeable holes h in a stack of wood strips v of a treatment tank t. Therefore, it is characterized in that the waste water to be added is discharged into the laminate without coming into direct contact with the atmosphere.
Japanese Examined Patent Publication No. 3-73358 (page 3-4, Fig. 1)

  However, in the wastewater treatment method disclosed in Patent Document 1, since the wastewater to be treated is poured into the stack of the wood strips v without directly contacting the atmosphere, the activity of aerobic microorganisms in the stack is increased. It was supposed to be suppressed. For this reason, in the lamination | stacking of the wood strip v, the balance of the activity of an aerobic microorganism and an anaerobic microorganism was destroyed, and it was in the state where efficient biological treatment was not performed.

  In addition, in the water injection pipe p, sludge and scum generated by sending the wastewater to be treated adhere to the inside of the water injection pipe p, and as a result of clogging the water permeation hole h, a situation that prevents the smooth addition of the wastewater to be treated has occurred. . For this reason, periodic maintenance work of the water injection pipe p is necessary, and this maintenance work is very complicated, and the maintenance cost is also increased.

Therefore, in view of such problems, the present invention activates the treatment with aerobic microorganisms, and smoothly disperses and adds wastewater to be treated, and realizes a wastewater treatment method that establishes a reduction in maintenance work. A processing device is provided.

First, as a wastewater treatment method for solving the above-described problems, there are the following methods.

  While forming the cylindrical processing tank (1) which uses a part or all of a side peripheral surface as a water-permeable material, the part or all is embed | buried in the ground. The lift (1) is filled with wood chips (21) made of chip-like small pieces to form a wood chip layer (2), and the air lift is made with the upper end opening exposed from the upper surface of the wood chip layer (2). A pump (4) is arranged. Then, after introducing the waste water to be treated into the air lift pump (4), the waste water is sprayed on the upper surface of the wood chip layer (2) by an air lift action, and is biologically treated with microorganisms existing in the wood chip layer (2). This method is suitable for the case of reprocessing wastewater that has been subjected to primary treatment such as aeration in an external system, for example, a combined treatment septic tank.

  The water permeable lumber constituting the side peripheral surface of the treatment tank (1) is appropriately selected from a net material (mesh material) and a punching metal material. The side surface of the wood chip layer (2) and waste water after biological treatment are used. It only needs to be able to penetrate into the surroundings.

  Alternatively, the waste water may be sprayed through a spray nozzle (5) disposed in the upper end opening of the air lift pump (4). The number of spray nozzles (5) may be one, but it is desirable to arrange a plurality of spray nozzles in consideration of spraying the waste water evenly on the upper surface of the wood chip layer (2).

In order to realize the above-described wastewater treatment method , the wastewater treatment apparatus (A) according to the present invention is configured as follows.

  That is, a processing tank (1) in which a part or all of the side peripheral surface is formed of a water-permeable material and has a part or all embedded in the ground, and a small piece in the processing tank A wood chip layer (2) formed by filling a wood chip (21) comprising a predetermined depth, and an air lift disposed in the wood chip layer (2) with the upper end opening exposed from the upper surface of the wood chip layer (2) It comprises a pump (4) and a water supply pipe (3) connected to an air lift pump (4) that introduces wastewater aerated in an external system such as a merged treatment septic tank.

In particular, the above-mentioned air lift pump (4) has a triple pipe structure with a coaxial arrangement, and is arranged in the order of the outer cylinder pipe (41), the pumping pipe (42), and the air supply pipe (43) from the outermost shell side. It is a configuration. The outer tube (41) is connected to the water pipe (3) and introduces the waste water aerated in the external merged treatment septic tank (T) into the apparatus (A). The upper end opening of the pumping pipe (42) is exposed from the upper surface of the wood chip layer (2). The air supply pipe (43) is connected to a blower (44) installed outside the processing tank (1). In addition, although the blower (44) may be arrange | positioned separately for this apparatus (A), you may make it use what is attached to the merger processing septic tank (T).

Moreover, this waste water treatment apparatus (A) has one or a plurality of spray nozzles (5) for spraying waste water to be treated on the upper surface of the wood chip layer (2), and a pumping pipe (42) of the air lift pump (4). It is arrange | positioned at the upper-end opening.

Further, a water test tube (6) is disposed in the device (A). The test pipe (6) has an upper end opening that is exposed to the outside of the processing tank (1) and extends substantially vertically to the bottom of the wood layer (2) in the processing tank (1). One or a plurality of water permeable ports (61) are formed on the side peripheral surface of the water test tube (6) located near the bottom of the treatment tank (1). Since this water-permeable opening (61) is formed for the purpose of collecting waste water near the bottom of the treatment tank (1) and testing it, it may be formed in a slit shape, and the entire bottom side is mesh material. You may make it comprise with.

  Note that the reference numerals in parentheses described in the claims and the means for solving the above problems are added with reference numerals for reference to facilitate understanding of the configuration of the invention. Of course, it is not limited to the above form.

  Since the wastewater treatment apparatus of the present invention is configured as described above, it exhibits the following effects.

  Since the wastewater to be treated in the treatment tank is sprayed by the air lift pump, the number of movable parts is smaller than that by the conventional pump, so that the failure is reduced. In addition, since the waste water is constantly agitated by the outside air and pumped up, sludge and scum are prevented from adhering inside the air lift pump.

  In addition, spraying wastewater with an air lift pump constantly introduces outside air into the wastewater, and as a result, aerobic treatment is activated in the wood chip layer, contributing to stable balance with anaerobic treatment, and improving the efficiency of biological treatment. It also has.

  In addition, because the wood chip layer placed inside the treatment tank is composed of chip-like small pieces, the microbial decomposition that occurred when the wood chip layer was composed of fine-grained sawdust and wood flour, sawdust, etc. Clogging due to further refinement can be prevented. As a result, it is possible to prevent the anaerobic fermentation layer from becoming anaerobic without impeding the penetration of the treated wastewater into the ground, and to promote an effective fermentation treatment for a long period of time. This eliminates the need to periodically stir the wood pieces, leading to a reduction in maintenance costs.

Below, the best embodiment of the waste-water-treatment apparatus concerning this invention is described in detail based on drawing.

  FIG. 1 is a partially cutaway perspective view showing the appearance of the wastewater treatment apparatus of the embodiment, and FIG. 2 is a longitudinal sectional view of the wastewater treatment apparatus of the embodiment.

  A wastewater treatment apparatus A (hereinafter referred to as “this apparatus”) according to the present embodiment reprocesses wastewater from a combined treatment septic tank T of a general house or the like. For this reason, most of the present apparatus A is usually buried under the ground surface in association with the merged treatment septic tank T as shown in FIG.

  Reference numeral 1 indicates a processing tank 1 which is a main part of the apparatus A. The external appearance is a substantially rectangular tube, and the base part 11 is constructed by laying on the bottom part where the ground surface GL is dug down to form the bottom face, the frame 12 standing on the base part, and the upper part of the base part 11 are integrally attached to the upper part. And a top frame 13 disposed in the vicinity of the surface.

  The base portion 11 is formed in a rectangular shape by laying concrete at the bottom of a predetermined space excavated from the ground surface GL.

  The frame 12 is composed of rigid rod-like struts 12a, 12a,... Erected at the corners of the base 11 and connecting rods 12b, 12b,.

  An opening 13b exposed to the ground surface GL with an annular rising portion 13a is formed at a substantially central portion of the top surface frame 13, and the opening 13b is covered with a lid 13c.

  The side peripheral surface of the treatment tank 1 is formed by attaching a water-permeable material (“water-permeable material”), for example, a mesh material or a punching metal material around the frame 12 in this embodiment. . The arrangement of the water permeable material may be all or part of the side peripheral surface as shown in the figure.

  In addition, although the processing tank 1 of a present Example employ | adopts the form which constructs | assembles the said structure in excavation space, for example, you may make it integrally manufacture beforehand in a factory etc. and may arrange | position in excavation space. .

The processing tank 1 is filled with wooden pieces 21 in a stacked manner to form the wooden piece layer 2, and a predetermined space is secured between the upper surface and the top frame 13. The wood piece 21 used here is preferably not a finely pulverized particle like sawdust or wood flour, but a chip-like piece (for example, a major axis of 20 to 50 mm, a minor axis of about 5 to 20 mm). There is no particular limitation. The reason for the small pieces is that they include not only homogeneous shapes such as plate shapes, cutting pieces shapes, rod shapes, etc., which are relatively fine shapes, but also random crushed pieces. The wood piece 21 of the present embodiment is a chip-like small piece and is a specially treated porous piece having a surface area of 30 m ² / g. This property provides an optimal living environment for the wastewater from the combined treatment septic tank T and microorganisms that inhabit the soil.

  As shown in FIG. 1 or FIG. 2, an air lift pump 4 is disposed substantially vertically at the center of the wood chip layer 2 of the treatment tank 1. The air lift pump 4 has a coaxially arranged triple pipe structure, and includes an outer cylinder pipe 41 constituting an outermost shell, a pumping pipe 42 arranged therein, and an air supply pipe arranged inside the pumping pipe 42. 43.

  A water supply pipe 3 for sending waste water from the merger processing septic tank T to a higher position in the middle is connected to the outer cylinder pipe 41 at a substantially right angle through a joint 31, and the inside of the outer cylinder pipe 41 and the outside of the pumping pipe 42 are connected. It communicates with the formed cylindrical space. Further, the bottom of the outer tube 41 is in contact with the base 11 of the processing tank 1 and is closed.

  The pumping pipe 42 has an open lower end portion extending to the vicinity of the lower end of the outer cylinder pipe 41, thereby communicating with the inside of the pumping pipe 42 near the bottom of the outer cylinder pipe 41. On the other hand, the upper end portion of the pumping pipe 42 is exposed to a predetermined height from the piece of wood layer 2 and is attached with two spray nozzles 5 and 5 extending in a substantially horizontal facing direction.

  In this embodiment, the two spray nozzles 5 are arranged diagonally, but this may be one, or three or more may be arranged radially.

  One end of the air supply pipe 43 is connected to a blower 44 disposed on the ground surface, and the air outlet 43a on the other end side is inserted to the vicinity of the bottom of the pumping pipe 42 and is arranged substantially coaxially. As the blower 44 used here, a blower having the same capacity as the low-capacity blower attached for aeration of the combined treatment septic tank T is usually used.

  In addition, a straight tubular test tube 6 is disposed inside the processing tank 1 so as to penetrate the wood piece layer 2 vertically. The upper end opening of the water test tube 6 penetrates the top frame 13 of the processing tank 1 and is exposed to the ground surface GL, and the lower end side is in contact with the base portion 11. In addition, a plurality of slit-shaped water passage openings 61 are formed on the side peripheral surface of the water test tube 6 located near the bottom of the treatment tank 1.

  Due to the structure of the test pipe 6, a part of the decomposed waste water near the bottom of the wood chip layer 2 is infiltrated and stored inside the test pipe 6 from the water passage 61, and this is stored at the upper end of the test pipe 6. Water can be sampled from the opening and the state of treatment of the wood chip layer 2 can be monitored.

Next, processing steps of the apparatus A will be described.
First, the waste water aerated in the combined treatment septic tank T flows between the outer tube 41 and the pumping pipe 42 via the water pipe 3 (arrow a). The wastewater that has flowed in has an apparent specific gravity that is smaller than that of air bubbles generated by air blowing from the air outlet 43a of the air supply pipe 43, and rises inside the pumping pipe 42 (arrow b). The spraying nozzle 5 sprays the upper surface of the wood chip layer 2 (arrow c). The sprayed wastewater penetrates into the wood chip layer 2 and is decomposed into water and carbon dioxide by microorganisms living inside, and then sequentially penetrates into the ground from the side peripheral surface of the water-permeable treatment tank 1. (Arrow d).

  The waste water sprayed as described above contains a large amount of compressed air in the pumping action of the air lift pump 4 and promotes the activation of aerobic microorganisms in the wood chip layer 2.

  In addition, this apparatus A has obtained the experimental result which purifies the organic waste water of BOD: 20mg / l to the level close | similar to rain water of BOD: 5mg / l or less by said waste water treatment.

It is a partially notched perspective view which shows the external appearance of the waste water treatment apparatus of an Example. It is a longitudinal cross-sectional view of the waste water treatment apparatus of an Example. It is a perspective view which shows the wastewater treatment apparatus of a prior art example.

Explanation of symbols

A This apparatus 1 Treatment tank 11 Base part 12 Frame 12a Support column 12b Connecting rod 13 Top frame 13a Start-up part 13b Opening part 13c Lid 2 Wood piece layer 21 Wood piece 3 Water supply pipe 31 Joint 4 Air lift pump 41 Outer cylinder pipe 42 Pumping water Pipe 43 Air supply pipe 43a Air outlet 44 Blower 5 Spray nozzle 6 Inspection pipe 61 Permeation port T Combined treatment purification tank t Treatment tank (conventional example)
v Wood chip h Permeability hole p Water injection pipe GL Ground surface

Claims (3)

A wastewater treatment apparatus for reprocessing wastewater aerated in an external system,
A treatment tank (1) having a bottomed cylindrical shape in which at least part or all of the side peripheral surface is formed of a water-permeable material, and part or all of which is buried in the ground,
A wood chip layer (2) formed by filling the processing tank (1) with wood chips (21) made of small pieces to a predetermined depth;
In the outer cylinder pipe (41) disposed substantially vertically in the wood chip layer (2), the pumping pipe (42) with the upper end opening exposed from the upper surface of the wood chip layer (2) is substantially coaxial. An air lift pump (4) which is housed and further accommodated in the pumping pipe (42) in a substantially coaxial manner with an air feed pipe (43) connected to a blower (44) installed outside the treatment tank (1);
A water supply pipe (3) connected to the outer cylinder pipe (41) of the air lift pump (4) in order to introduce waste water aerated in an external system;
A wastewater treatment apparatus characterized by comprising: One or more spray nozzles (5) for spraying the waste water to be treated on the upper surface of the wood chip layer (2) are arranged in the upper end opening of the pumping pipe (42) of the air lift pump (4). The wastewater treatment apparatus according to claim 1. A test tube (6) having an upper end opening exposed to the outside of the processing tank (1) and extending to the vicinity of the bottom surface of the wood chip layer (2) in the processing tank (1) is disposed in a substantially vertical shape. The wastewater treatment apparatus according to claim 1 or 2, wherein one or a plurality of water permeable ports (61) are formed on a side peripheral surface located near the bottom of the treatment tank (1) of (6).

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