JP2009291725A - Sewage treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the treatment efficiency of a whole sewage treatment apparatus by efficiently performing an additional pretreatment for an anaerobic treatment in the sewage treatment apparatus. <P>SOLUTION: The sewage treatment apparatus primarily keeps an anaerobic treatment tank and an aerobic treatment tank installed in this order. A pretreatment tank 13 is installed before the anaerobic treatment tank. Within the anaerobic treatment tank 15 the pretreatment tank 13 comprises a contact material mat 20 having a core material made up of a three-dimensional thick-plate net body along which sludge sticking yarn is disposed, and further comprises sprinkling means 28 for sprinkling the sewage 18 to be treated in the tank over the contact material mat 20. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sewage treatment apparatus.

  As a method for treating organic wastewater, which is sewage, standard activated sludge method is mainly used, including public sewerage. As a sewage treatment apparatus for carrying out the standard activated sludge method, for example, there is one that treats using an anaerobic treatment tank. However, since the entire process of BOD decomposition is performed only by anaerobic treatment, the efficiency is extremely low.

In order to improve the treatment efficiency, an anaerobic treatment tank is installed in the previous stage, and an aerobic treatment tank is installed in the subsequent stage, and denitrification by denitrifying bacteria is performed in the anaerobic treatment tank under anoxic conditions with respect to the inflow wastewater. Next, oxidative decomposition of organic compounds and nitrification of ammonia by nitrifying bacteria are performed on activated sludge in the presence of oxygen in the aerobic tank, and the nitrification liquid from the aerobic tank is transferred to the anaerobic tank. There is a sewage treatment apparatus that promotes the denitrification reaction in the anaerobic treatment tank by returning it. Such a sewage treatment apparatus is described in Patent Document 1 and the like.
JP-A-5-317884 (particularly [0004], FIG. 3)

  However, even the one described in Patent Document 1 has poor reaction efficiency in the anaerobic treatment tank, requires a lot of time for the treatment, and therefore the residence time of the sludge to be treated in the tank is long. For this reason, when it is going to improve processing capacity, there exists a problem that an installation must be enlarged. In addition, if an advanced treatment of sewage is carried out, new equipment corresponding to the wastewater treatment is required and a high level of technology is required, resulting in a significant increase in cost.

  Accordingly, an object of the present invention is to improve the efficiency of the entire sewage treatment apparatus by performing pretreatment for anaerobic treatment and efficiently performing the pretreatment.

  In order to achieve this object, the present invention provides a sewage treatment apparatus in which an anaerobic treatment tank and an aerobic treatment tank are installed in this order, and a pretreatment tank is provided before the anaerobic treatment tank. The tank comprises a mat-shaped contact material having a structure in which a sludge adhering yarn is arranged along the core material in the anaerobic tank with a three-dimensional thick plate-shaped net body. And means for spraying the treated wastewater in the tank to the contact material.

  According to the present invention, since the pretreatment tank having the contact material having a specific configuration and the means for spraying the water to be treated in the tank is provided on the front stage of the aerobic treatment tank, the anaerobic treatment is performed. Can be efficiently performed, and the effect of improving the decomposability in the subsequent aerobic treatment tank can be expected. In the aerobic treatment tank, the treatment can be performed in a high MLSS state. In addition, a hard and large sludge can be formed in the pretreatment tank, which can also improve the treatment efficiency.

  FIG. 2 shows a schematic configuration of the sewage treatment apparatus according to the embodiment of the present invention. Here, 11 is an anaerobic treatment tank, 12 is an aerobic treatment tank, and these are installed in this order. A pretreatment tank 13 is provided upstream of the anaerobic treatment tank.

  FIG. 1 shows the detailed structure of the pretreatment tank 13. That is, 15 is a closed processing tank, and is configured so that an anaerobic atmosphere can be created therein. 16 is a raw water supply path to the inside of the tank 15, and 17 is a treated water discharge path from the tank 15. A storage portion 19 for the water to be treated 18 is provided on the bottom side inside the treatment tank 15.

  A contact material 20 is provided in a portion above the storage portion 19 inside the processing tank 15. The contact material 20 is arranged as a large number of elements inside a metal frame, and each element, that is, each contact material 20 constitutes a core material with a three-dimensional thick plate-like net body. In addition, a sludge-attached yarn is arranged along the core material to form a mat. The contact material 20 having such a configuration is described in Japanese Patent Laid-Open No. 2002-136986.

  As shown in FIGS. 3 to 6, the element 26 of the contact material 20 has a three-dimensional net-like core material 21, and a sludge adhesion yarn 22 is arranged along the core material 21. ing.

  The core material 21 is composed of, for example, a strong monofilament 23 made of synthetic resin, and the monofilament 23 is composed of, for example, a plurality of Ω-shaped portions and inverted Ω-shaped portions alternately as shown in FIG. It is comprised by the continuous thread arrange | positioned in uneven | corrugated shape. In the core material 21, a plurality of monofilaments 23, 23,... Are arranged in parallel, and Ω-shaped portions of adjacent monofilaments 23, 23, that is, convex portions or inverted Ω-shaped portions, that is, concave portions. Are connected to each other by the connecting thread 24 to form a three-dimensional net as described above.

  The connecting yarn 24 is formed of, for example, a continuous continuous yarn made of synthetic resin having a finer fineness than that of the monofilament 23, and one end portion and the other end portion along the thickness direction of the three-dimensional net-like core material 21. In FIG. 2, a plurality of connecting yarns 24 are arranged so as to be entangled with one monofilament 23, and the Ω-shaped portions or the inverted Ω-shaped portions of adjacent monofilaments 23, 23 are overlapped with each other. The character-shaped portions or the inverted Ω-shaped portions can be connected to each other.

  In addition, a plurality of connecting yarns 24 are passed in the length direction of the monofilament 23 in a portion 25 where the monofilament 23 in the Ω-shaped portion or the inverted Ω-shaped portion of the monofilament 23 does not exist and is open. It becomes the composition. And the connection thread | yarn 24 is arrange | positioned only at the one end part and the other end part along the thickness direction of the three-dimensional net-like core material 21 in this way, and the inner side along the thickness direction of this core material 21 It is comprised so that it may not be arrange | positioned in this part.

  A sludge-attached yarn 22 is arranged along the three-dimensional net-like core material 21 having such a configuration. The sludge adhering yarn 22 is formed of a yarn having water absorbency and good sludge adhering property such as acrylic high bulk fiber, and is thicker than the monofilament 23 constituting the core material 21. The three-dimensional space formed by the fineness is formed so as to occupy a predetermined volume ratio.

  The sludge adhering yarn 22 is arranged so as to have an uneven shape opposite to the monofilament 23 of the core material 21. That is, the Ω-shaped convex portion of the monofilament 23 becomes an inverted Ω-shaped concave portion, and conversely, the reverse Ω-shaped concave portion of the monofilament 23 becomes an Ω-shaped convex portion along the monofilament 23. Has been placed. That is, the sludge adhering yarn 22 is disposed in the opening 25 at one end and the other end along the thickness direction of the core material 21. Then, the sludge adhering yarn 22 is entangled with the connecting yarn 24 at the opening 25 and is bound to the monofilament 23 by the connecting yarn 24 at the edge of the opening 25 so that the three-dimensional shape is obtained. It is integrated with the net-like core material 21. In the inner portion along the thickness direction of the core material 21 other than the one end and the other end along the thickness direction of the core material 21, the sludge adhering yarn 22 extends along the monofilament 23, but this monofilament 23 It is arrange | positioned in the free state which floated from the monofilament 23, without being connected to.

  3 is a three-dimensional view of the entire element 26, FIG. 4 is a three-dimensional view in which the arrangement direction of each monofilament 23 and sludge adhering yarn 22 is a horizontal direction, and FIG. 5 is each monofilament 23 and sludge adhering yarn 22. FIG. 6 is a diagram in which a direction perpendicular to the arrangement direction of the monofilaments 23 and the sludge adhering yarns 22 is taken as the horizontal direction.

  In the above description, the element 26 of the first contact member 20 has a specific woven structure, but the element 26 that can be used in the present invention is not limited to this. It has a core material composed of a three-dimensional thick plate-like net body using other known woven structure and other three-dimensional structures, and sludge adhering yarn arranged along this core material. Any mat may be used.

  As shown in FIG. 1, water to be treated 18 of the storage unit 19 is sprinkled from the upper side of the contact material 20 toward the contact material 20 in a portion above the contact material 20 in the treatment tank 13. A watering device 28 is provided. The watering device 28 is constituted by, for example, a spray nozzle or the like, and is connected to a supply pipe 30 provided with a pump 29. Further, as shown in FIG. 1, the gas present in the space 31 between the contact material 20 and the water to be treated 18 of the storage unit 19 is blown toward the contact material 20 from above the contact material 20. A gas supply pipe 33 including a blower 32 is provided.

  In such a configuration, the treated water 18 supplied from the raw water supply path 16 to the inside of the treatment tank 15 in the anaerobic atmosphere and stored in the storage unit 19 is supplied from the sprinkler 28 through the supply pipe 30 to the contact material 20. It is sprayed toward. Then, since the contact material 20 is composed of a water-absorbing material as described above, the entire contact material 20 is wetted by the water to be treated 18 and is operated without a dry portion. Become. For this reason, the to-be-processed water 18 can be efficiently processed with the contact material 20. FIG. In other words, the required treatment can be performed with only a small amount of watering, and there is an advantage that a large amount of water for spraying need not be supplied to the watering device 28 by the pump 29. For this reason, an apparatus can be comprised in a small size, Therefore A lightweight sewage treatment apparatus can be provided. In addition, the capacity of the pump 29 may be low, so that both the initial cost and the running cost can be reduced. Moreover, since the contact material 20 is configured in a mat shape as described above, a large amount of generated sludge can be retained.

  From the above, anaerobic treatment can be performed efficiently. For this reason, in the subsequent aerobic processing tank 12 shown in FIG. 2, while being able to expect a degradability improvement effect, it can process in a high MLSS state. Moreover, a hard and big sludge can be formed in the pretreatment tank 13, and the improvement of processing efficiency can also be aimed at by this.

  Further, since the gas in the tank can be sprayed onto the contact material 20 by the gas supply pipe 33 provided with the blower 32, the contact material 20 can be cleaned, for example, by blowing off sludge adhering to the contact material 20. it can.

  Since the pretreatment tank 13 is configured as described above, the structure is simple, and therefore, it is low-cost and lightweight, and the contact material 20 can be installed in a small place by being stacked in multiple stages. . Moreover, since the structure is simple, maintenance is easy.

It is a figure which shows the structure of the pre-treatment tank in the sewage treatment apparatus of embodiment of this invention. It is a figure which shows the whole structure of the sewage treatment apparatus of embodiment of this invention. It is a three-dimensional view of the contact material in FIG. FIG. 4 is a three-dimensional view showing a knitted structure of the contact material of FIG. 3. It is a principal part enlarged view which shows the knitting structure of the contact material of FIG. It is another perspective view which shows the knitting structure of the contact material of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Anaerobic processing tank 12 Aerobic processing tank 13 Pretreatment tank 20 Contact material 21 Core material 22 Sludge adhesion yarn 28 Water sprinkler

Claims (2)

  An anaerobic treatment tank and an aerobic treatment tank are installed in this order, and a pretreatment tank is provided in front of the anaerobic treatment tank, and this pretreatment tank is an anaerobic tank. In addition, the core material is constituted by a three-dimensional thick plate-like net body and the mat-like contact material having a structure in which sludge adhering yarn is arranged along the core material, and the treated sewage in the tank A sewage treatment apparatus comprising a means for spraying the contact material.   2. A sewage treatment apparatus according to claim 1, further comprising means for blowing the gas in the tank onto the contact material.

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