JP2006088028A - Anaerobic biofiltration septic tank, sewage treatment system, and sewage treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively treat organic waste water by providing an anaerobic biofiltration septic tank which can increase the efficiency of anaerobic treatment, and obtain water quality sufficient to recycle the treated water. <P>SOLUTION: Sewage is made to flow into an aerobic regulating reservoir 10, and retained therein for 10-20 days to insolubilize/decompose organic matter. Black soil is spread all over the bottom of the regulating reservoir 10, and filter medium are circularly disposed on the central part. By feeding effective microorganisms (EM), the EM are fixed on the filter medium. The treated water of the regulating reservoir 10 is made to flow into the anaerobic biofiltration septic tank 12. The anaerobic biofiltration septic tank 12 is covered with a sheet, and its inside is kept in an anaerobic condition. The inside of the anaerobic biofiltration septic tank 12 is divided into many chambers, and each chamber is filled with the filter medium. The sewage flows vertically and horizontally in each chamber, and is brought into contact with the filter medium to be treated. The EM are also added to the anaerobic biofiltration septic tank 12 to be fixed on the filter medium. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to an anaerobic biological filtration septic tank in which sewage is subjected to biological filtration using anaerobic microorganisms to obtain clear treated water, and a sewage treatment system using the same.

  2. Description of the Related Art Conventionally, biological treatment apparatuses using microorganisms have been used for various organic wastewater (sewage) treatment such as domestic wastewater and livestock wastewater.

  For example, septic tanks using aerobic organisms are widely used as household wastewater treatment equipment, and the activated sludge method using suspended microorganisms and the submerged filter bed method using microorganisms adhering to filter media are adopted. ing. On the other hand, the activated sludge method is widely used for the treatment of high-concentration organic wastewater (sewage) such as livestock wastewater.

  However, in these aerobic treatments, in order to maintain the activity of the aerobic microorganisms in the treatment tank, it is necessary to supply oxygen to the treatment tank, and air from the blower or the like is sent into the treatment tank and aerated in the treatment tank. There is a need. Therefore, there is a problem that power for blowing air is consumed, and sludge extraction and processing costs increase.

  On the other hand, there is an anaerobic treatment as a treatment using microorganisms. According to this, the treatment can be performed by leaving the sewage as it is, and no energy is required. However, this anaerobic treatment has problems that treatment efficiency is poor, treatment time is long, and treated water quality is relatively poor.

  In addition, there exists description in patent document 1 etc. about the anaerobic process which uses a contact material.

JP 2002-45885 A

  The present invention provides an anaerobic biofiltration septic tank capable of increasing the treatment efficiency of anaerobic treatment and making the water quality sufficient to recycle treated water.

  The present invention is an anaerobic biological filtration and purification tank that accepts sewage and performs biological treatment using a filter medium carrying anaerobic bacteria, wherein the treatment tank is formed with a plurality of elongated treatment chambers partitioned by a partition wall. Each processing chamber has a circulation port at one upper end and a lower end at the other end, and the sewage flowing from one circulation port flows out from the other circulation port, and thereby into a plurality of processing chambers. Sewage flows in sequence, each processing chamber is separated from the surrounding wall, submerged to the upper end, a porous filter medium carrying anaerobic microorganisms is immersed, and while the sewage is in contact with the filter medium, It is characterized by anaerobic biological treatment of sewage by circulating in each treatment chamber.

  The filter medium preferably includes both a porous stone block and a sponge-like material.

  Moreover, it is preferable that the circulation port provided in the upper part on the one end side functions as an overflow cough.

  Moreover, it is preferable that EM bacteria are used as the anaerobic microorganism.

  Further, the present invention is a sewage treatment system using the anaerobic biological filtration septic tank, wherein an adjustment pond for storing sewage at one end is provided in the previous stage of the anaerobic biological filtration septic tank, and the sewage is retained in the adjustment pond for a predetermined period of time. It is characterized by flowing sewage into the anaerobic biological filtration septic tank.

  The adjustment pond is preferably formed in a structure in which a hole is dug in the soil and sewage does not penetrate into the ground.

  Moreover, it is preferable to spread a predetermined amount of soil on the bottom of the adjustment pond.

  Further, it is preferable that a filter medium carrying bacteria is immersed in the adjustment pond.

  Further, the present invention is a sewage treatment method for accepting sewage and performing biological treatment using a filter medium supporting anaerobic bacteria, and at the start of sewage treatment, EM bacteria are previously supported on the filter medium, The waste water flows in while adding EM bacteria, and the EM bacteria carried on the filter medium are used to perform anaerobic treatment of the sewage.

  In this way, sewage flows and flows through the processing chamber, and contact between the sewage and the filter medium is achieved. Therefore, the organic matter in the sewage is effectively treated by the anaerobic microorganisms supported on the filter medium. Furthermore, the processing chamber is configured to flow out from the lower part when sewage flows from the upper part, and to flow out from the upper part when flowing from the lower part. Therefore, the contact between the sewage and the filter medium is efficiently performed, and an effective treatment can be performed.

  Moreover, effective treatment can be performed from the beginning by carrying out sewage treatment after carrying EM bacteria on the filter medium in advance.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of the entire processing system. Organic sewage (raw water) such as livestock wastewater is first introduced into the regulating pond 10 and retained therein for a predetermined period, for example, about 10 to 20 days. In the adjustment pond 10, the adjusted adjustment water is introduced into the anaerobic multilayer biological filtration clarification tank 12 by the pump P, where organic substances are decomposed by the anaerobic microorganisms. The treated water in the anaerobic biological filtration septic tank 12 is introduced into the reservoir 14 by the pump P and stored therein. Then, the treated water in the reservoir 14 is appropriately recycled to sprinkling water, washing water and the like.

  The adjustment pond 10 has a configuration as shown in FIG. 2 and is formed to be waterproof by disposing a water shielding sheet in a recess dug in the ground. Further, the adjustment pond 10 is installed outdoors (in a rainy condition), and the inside is maintained in an aerobic state.

  The adjustment pond 10 has a depth of about 2 m, and black soil is accommodated in a thickness of about 50 cm at the bottom thereof. This black soil contains soil fungi, and this soil fungus works synergistically with EM fungi described later to promote solubilization and decomposition of organic matter in the wastewater.

  Further, the filter medium 20 is arranged in an annular shape (for example, a radius of about 2.5 m) on the black soil. In addition, the adjustment pond 10 has a length of 5 m, a width of 15 m, and a depth of about 2.3 m.

  Here, the filter medium 20 will be described based on the plan view of FIG. 3A and the front view of FIG. Thus, the filter medium 20 is composed of a large number of units, and one unit is composed of a central portion 20a filled with a large number of pumice stones and a peripheral portion 20b filled with polyurethane disposed on both sides thereof. Yes. And these are accommodated in the plastic container 20c. The plastic container 20c is open at the top and has a plastic bottom at the bottom. In addition, the peripheral part is a mesh, and the sewage comes into contact with the internal pumice, polyurethane, and the like. Moreover, it is preferable that the pumice be wrapped with a plastic netting material. Further, a weight is put on the filter medium 20 so as not to float.

  One unit has a size of about 650 mm long × 340 mm wide × 270 mm high as its outer shape, and the lengths of the polyurethane filling portions on both sides and the pumice filling portion in the middle are about 200 mm each. Yes. In addition, the pumice preferably has a diameter of about 40 mm.

  Further, the adjustment pond 10 is provided with a sprinkler S, and floating water such as scum floating on the surface of the adjustment pond 10 by spraying treated water or the like on the surface of the sewage (adjustment water) in the adjustment pond 10. Precipitates.

  Moreover, it is suitable to employ | adopt the filter medium 20 as what a EM microbe tends to fix. Here, EM fungus refers to a group of microorganisms that are useful in the natural environment, and is an abbreviation that stands for Effective (useful) and Microorganisms (microorganisms). EM bacteria are composed of various microorganisms, and roughly classified into groups of photosynthetic bacteria, lactic acid bacteria, yeast, actinomycetes, and filamentous fungi. Each bacterium has its own characteristics, and it produces sugars and amino acids using bacteria that prevent the strong oxidative state due to water pollution and other nutrients that produce useful microorganisms for growth and harmful methane gas and hydrogen sulfide as substrates. Bacteria and bacteria that suppress the spoilage decomposition of harmful microorganisms by producing lactic acid are complex-cultured, and have a much greater effect than useful microorganisms work alone.

  It is preferable to inject an appropriate amount of this EM fungus at each stage of the treatment. In addition, when there is too much injection amount, the treated water BOD value will become high.

  In the adjustment pond 10, it is preferable to inject about 0.03% of EM bacteria with respect to the amount of sewage, whereby the EM bacteria are supported on the filter medium 20. And the aerobic solubilization and decomposition | disassembly of organic substance progress by the synergistic effect of the soil microbe in the black soil mentioned above, and EM microbe. In addition, in the adjustment pond 10, when soil bacteria are not used but only EM bacteria are used, decomposition takes time, and sufficient treatment cannot be performed unless the residence time is increased.

  In this manner, the aerobic treatment is performed in the adjustment pond 10 to decompose the organic matter. When processing, dig a hole larger than the expected inflow volume in the soil and lay a water-impervious sheet. Then, black soil corresponding to about 20% of the planned amount of inflow sewage is spread over the bottom of the adjustment pond 10.

  Next, the filter medium 20 is installed in an annular shape on the black soil. This installation is as described above. Thus, after the filter medium 20 is installed in the adjustment pond 10, 9% of the expected amount of inflow sewage is added, 0.03% of EM bacteria is injected, the EM bacteria are fixed on the filter medium 20, and the sewage flows in. To do.

  Then, by retaining for about 10 to 20 days, the organic matter in the influent sewage is solubilized and decomposed by the synergistic effect of the soil bacteria and the EM bacteria. In the adjustment pond 10, when the odor becomes weak, the pump P is driven to supply adjustment water to the anaerobic biological filtration septic tank 12.

  Next, the anaerobic biological filtration septic tank 12 has a configuration as shown in FIG. In addition, a dark sheet is fixed to the upper part of the anaerobic biological filtration purification tank 12 to cover the upper part. And the inside of a tank is maintained in an anaerobic state. Three anaerobic filter floor tanks 32a, 32b, and 32c are formed on the entrance side of the reinforced concrete tank body 30 by partition walls. The adjustment water flows into the anaerobic filter bed tank 32a from the top, and the overflow water flows into the adjacent anaerobic filter bed tank 32b. The overflow part is provided with a cover 34a that covers the overflow part and extends downward, and the adjustment water in the anaerobic filter floor tank 32a rises from the lower part of the cover to the overflow part. It flows into the anaerobic filter floor tank 32b. Therefore, the adjustment water flows into the upper part of the anaerobic filter floor tank 32b. Similarly, the overflow portion and the cover 34b are provided in the anaerobic filter bed tank 32b, and the adjustment water in the anaerobic filter bed tank 32b rises inside the cover 34b and flows into the anaerobic filter bed tank 32c. The anaerobic filter floor tank 32c has the same configuration, and the adjusted water that has risen in the cover 34c flows into the anaerobic treatment section 40 from the overflow section.

  The anaerobic treatment unit 40 is partitioned into six elongated rectangular parallelepiped contact chambers 42a to 42f by a partition wall. In each of the contact chambers 42a to 42f, filter media 44a to 44f are accommodated, respectively. The filter media 44a to 44f have a rectangular parallelepiped shape that is smaller than the internal space of the contact chambers 42a to 42f by a predetermined amount, and are installed on the bottom surfaces in the contact chambers 42a to 42f with spaces above and around it.

  And the adjustment water from the anaerobic filter floor tank 32c passes the six contact chambers 42a-42f in order. That is, the inflow water from the anaerobic filter floor tank 32c flows from the upper end of the contact chamber 42a, and flows into the contact chamber 42b from the opening provided at the bottom of the other end of the contact chamber 42a. The outflow water of the contact chamber 42a flows from the bottom of the contact chamber 42b and flows into the contact chamber 42c from the overflow portion at the other end of the contact chamber 42b. The contact chamber 42c flows in from the top, flows out from the bottom, the contact chamber 42d flows in from the bottom, flows out from the top, the contact chamber 42e flows in from the top, flows out from the bottom, and the contact chamber 42f flows in from the bottom. Outflow. The water to be treated flows not only vertically but also horizontally in the contact chambers 42a to 42f, whereby sufficient contact with the filter medium 44 is performed.

  As described above, in the anaerobic biological filtration septic tank 12, the water to be treated flows along the filter medium 44 in the contact chamber 42. Thus, the water to be treated appropriately enters the inside of the filter medium 44 and comes into contact with microorganisms carried on the filter medium 44. Therefore, the organic matter in the water to be treated is decomposed by the microorganisms supported on the filter medium 44. Anaerobic microorganisms have a slow growth rate, but can be maintained in the contact chamber 42 at a high concentration by being held in the filter medium 44. For this reason, an effective process can be performed in each contact chamber 42, and organic substances in the water to be treated can be effectively decomposed and removed.

  In addition, about the filter medium 44 of this anaerobic biological filtration purification tank 12, the filter medium similar to the above can be utilized. In addition, the height of the filter medium 44 in the anaerobic biological filtration septic tank 12 is higher. For example, the filter medium 44 has a width of 650 mm, a length of 4.3 m, and a height of 1.35 m.

The anaerobic biological filtration clarification tank 12 is manufactured with an RC structure as described above, and a filter medium 44 is disposed in each contact chamber 42. Then, before the start of the purification treatment, the contact chambers 42 a to 42 f are filled with EM bacteria of about 0.004% of the volume of each chamber, and the filter medium 44 carries the EM bacteria. Then, in the adjustment pond 10, the sewage adjusted for 10 to 20 days flows into the anaerobic biological filtration septic tank 12 at 15 to 20 m ³ / day. At this time, about 0.004% of the aqueous solution which mixed EM bacteria with 200 times the water is added with respect to the inflow water to the anaerobic biological filtration purification tank 12. In this way, 45 to 60 m ³ of sewage is purified in the case of operation for 3 days.

  The effluent water from the contact chamber 42f passes through the treated water tank 50, then passes through the charcoal storage chamber 52, and further flows out from the adjustment chamber 54 as treated water. Further, charcoal having a diameter of φ = 4 to 8 cm and a length of about 10 cm to 20 cm is adopted, and flows into the charcoal storage chamber 52 from the upper part and flows out from the lower part.

  Moreover, also about the process of 2nd transfer, an appropriate amount EM microbe is added and processed. First, after the sewage flows into the adjustment pond 10, 0.03% of EM bacteria of the amount of sewage is added, and about 0.004% of an aqueous solution obtained by mixing EM bacteria with 200 times the water is added to the inflow adjustment water. To do. Furthermore, about 0.004% of EM bacteria of each chamber capacity are added to the anaerobic biological filtration septic tank 12. Thus, a suitable process can be continued by adding a predetermined amount of EM bacteria.

  Furthermore, when receiving sewage regularly, the capacity | capacitance of the adjustment pond 10 is made into the capacity | capacitance for 10 to 20 days of inflow sewage, and it adjusts in this adjustment pond 10 and processes. In this case, the amount of EM bacteria added is also the same as in the batch type described above.

  Although not shown in FIG. 4, as shown in FIG. 1, the treated water tank 50 is provided with a pump P, and a part of the water in the anaerobic treatment unit 40 is supplied to the adjustment pond 10 or anaerobic. It can return to the filter bed tank 32a. For example, the treated water in the treated water tank 50 is returned to the adjustment pond 10 as circulating water when there is no inflow water. Further, when it is necessary to further lower the BOD value of the treated water, the treated water is returned to the anaerobic filter bed tank 32 and reprocessed.

  The reservoir 14 into which treated water from the anaerobic biological filtration clarification tank 12 is stored is basically formed of a water shielding sheet in the same manner as the regulating pond 10.

  About livestock wastewater, the treatment experiment was done using the sewage treatment system described in the above-mentioned embodiment.

The raw water was BOD 2,030 mg / L and 1.4 million E. coli / cm ³ . This raw water was treated to obtain septic tank treated water having a BOD of 15 to 30 mg / L and 0 E. coli / cm ³ . In addition, no sludge precipitation has been confirmed.

  Thus, according to the sewage treatment system by this embodiment, very clear treated water can be obtained.

  In particular, in this embodiment, an aerobic process is performed in the adjustment pond 10 and then an anaerobic process is performed by the anaerobic biological filtration septic tank 12. In general, anaerobic treatment is performed after anaerobic treatment, but the order is opposite. However, by treating in the reverse order, the above-described suitable sewage treatment is performed.

It is a figure which shows the whole structure of a sewage treatment system. It is a figure which shows the structure of an adjustment pond. It is a figure which shows the structure of a filter medium. It is a figure which shows the structure of an anaerobic biological filtration septic tank.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Adjustment pond, 12 Anaerobic biological filtration purification tank, 14 Reservoir, 20 Filter medium, 30 Tank body, 32 Anaerobic filter floor tank, 34 Cover, 40 Anaerobic treatment part, 42 Contact room, 44 Filter medium, 50 Treated water tank, 52 Charcoal storage room 54 Adjustment room.

Claims (9)

An anaerobic biological filtration septic tank that accepts sewage and performs biological treatment using a filter medium carrying anaerobic bacteria,
A treatment tank having a plurality of elongated treatment chambers partitioned by a partition wall;
Each treatment chamber is provided with a circulation port at one upper end and a lower end at the other end, and sewage flowing from one circulation port flows out from the other circulation port,
As a result, the sewage sequentially flows through the plurality of processing chambers,
In each processing chamber, a porous filter medium carrying anaerobic microorganisms is immersed and arranged so as to be submerged to the upper end, separated from the surrounding wall.
An anaerobic biological filtration septic tank, wherein the sewage is anaerobically treated by flowing through each processing chamber while the sewage is in contact with the filter medium. In the anaerobic biological filtration septic tank according to claim 1,
The anaerobic biological filtration septic tank, wherein the filter medium includes both a porous stone block and a sponge-like material. In the anaerobic biological filtration septic tank according to claim 1 or 2,
An anaerobic biological filtration septic tank characterized in that a circulation port provided at the upper end of the one end functions as an overflow cough. In the anaerobic biological filtration septic tank according to any one of claims 1 to 3,
An anaerobic biological filtration septic tank using EM bacteria as the anaerobic microorganism. A sewage treatment system using the anaerobic biological filtration septic tank according to any one of claims 1 to 4,
A sewage treatment system characterized in that an adjustment pond for storing sewage at one end is provided in the previous stage of the anaerobic biofiltration septic tank, and the sewage retained in the adjustment pond for a predetermined period is caused to flow into the anaerobic biofiltration septic tank. The system of claim 5, wherein
The sewage treatment system is characterized in that the adjustment pond is formed in a structure in which a hole is dug in the soil and sewage does not penetrate into the ground. The system according to claim 5 or 6,
A sewage treatment system, wherein a predetermined amount of soil is spread on the bottom of the adjustment pond. In the system according to any one of claims 5 to 7,
A sewage treatment system, wherein a filter medium carrying bacteria is immersed in the adjustment pond. A sewage treatment method for accepting sewage and performing biological treatment using a filter medium supporting anaerobic bacteria,
At the start of sewage treatment, EM bacteria are preloaded on the filter medium,
Then, sewage is introduced while adding EM bacteria, and the sewage is anaerobically treated using the EM bacteria supported on the filter medium.

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