JP2005296803A - Sewage treatment tank, and method of deodorizing sewage treatment tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sewage treatment tank capable of being deodorized effectively by a simple apparatus, and to provide a method of deodorizing the sewage treatment tank. <P>SOLUTION: The sewage tratment tank is provided with an anaerobic treatment tank, an aerobic treatment tank having an air diffusing member and an air lift pump for circulating a part of liquid in the aerobic treatment tank to the anaerobic treatment tank and further an ozone generator is provided in the middle of an air supply tube for supplying air to the air diffusing member and the air lift pump. Further the sewage treatment tank is provided with a deodorizing catalyst at a position higher than a water surface of treated water therein. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sewage septic tank for treating manure, other domestic sewage, kitchen sewage, disposer sewage or the like, or a combined sewage (hereinafter also referred to as sewage), and a deodorizing method for the sewage septic tank. It relates to what deodorizes.

  Usually, the inflowing sewage in the sewage septic tank contains a lot of substances that cause bad odor. These malodorous sources, specifically protein, urea, etc. are mainly anaerobically decomposed in an anaerobic treatment tank (precipitation separation tank, anaerobic filter bed tank, contaminant removal tank, etc.), and hydrogen sulfide, mercaptans, methylamines. It becomes a malodorous substance such as ammonia. In particular, when sewage more than the planned load flows into the sewage septic tank, the oxidation-reduction potential in the anaerobic treatment tank decreases, anaerobic decomposition is promoted, and the amount of these odor generating substances generated increases.

  Part of the generated odor-generating substance volatilizes from the surface of the anaerobic treatment tank, is released to the space inside the sewage purification tank due to aeration in the aerobic treatment tank, or in some cases from the manhole of the sewage purification tank Leak outside. As a countermeasure in such a case, a scented tube is installed in the septic tank.

  Various methods such as a biological deodorization method, a masking method, an adsorption method, a chemical addition method, and an ozone oxidation method have been proposed as a method for deodorizing a sewage septic tank other than installing a odor tube. Among these, the ozone oxidation method has been studied because it has a feature that the apparatus is simple and can decompose most offensive odor substances except ammonia.

FIG. 4 shows an example of a deodorizing method for a sewage septic tank to which the ozone oxidation method is applied. In the deodorization method, ozone is supplied into the treatment chamber 51 from an ozone supply pipe 50 communicating with the sewage inflow pipe 20, and deodorization is performed by reacting ozone with an odorous substance in the gas phase (patent) Reference 1). Also proposed is a method of deodorizing by supplying ozone-containing air to the upper space part of the sewage septic tank or the diffuser member of the aerobic treatment tank and maintaining the ozone concentration in the tank space part at around 0.1 ppm. (See Patent Document 2).
Japanese Patent No. 3406253 JP 2000-233192 A

  By the way, while ozone has a strong oxidizing power, it is known that the reaction rate with odorous substances is slow in the gas phase. For this reason, the method of simply supplying ozone to the space in the septic tank as in Patent Document 1 has a problem that the reaction between ozone and odorous substances is difficult to proceed unless the ozone concentration is secured to a certain level. . In addition, in the above method, the generation of odorous substances in the liquid in the tank cannot be suppressed, and the odorous substances dissolved in the liquid cannot be oxidatively decomposed. There was a problem that it was difficult.

  Further, in the method described in Patent Document 2, oxidative decomposition of the odorous substance dissolved in the liquid can be expected to some extent, but since the generation of the odorous substance in the anaerobic treatment tank cannot be suppressed, the deodorization efficiency is poor. There was a problem with.

  An object of the present invention is to provide a sewage septic tank and a sewage septic tank deodorization method capable of effectively deodorizing with a simple apparatus.

In order to achieve the above object, the present invention has the following configuration.
(1) The present invention includes an anaerobic treatment tank, an aerobic treatment tank having an aeration member, and an air lift pump for circulating a part of the liquid in the aerobic treatment tank to the anaerobic treatment tank, The sewage septic tank is provided with an ozone generator in the middle of an air supply pipe for supplying air to the air diffuser and the air lift pump.
(2) Further, in item (1), the sewage septic tank further includes a deodorizing catalyst in a sewage septic tank at a position higher than the surface of the treated water.
(3) Deodorization of a sewage purification tank further comprising an anaerobic treatment tank, an aerobic treatment tank having an aeration member, and an air lift pump that circulates a part of the liquid in the aerobic treatment tank to the anaerobic treatment tank. This is a method for deodorizing a sewage septic tank, wherein the air supplied to the air diffusing member and the air lift pump is ozone-containing air.

  If a deodorizing catalyst is provided in a part of the space in the tank, ozone and the odorous substance react with each other on the surface of the deodorizing catalyst to decompose the odorous substance, further improving the deodorizing efficiency, and excessive ozone is also decomposed to decompose the sewage purification tank. Ozone can be prevented from leaking outside the manhole.

  Further, according to the above method, not only can the oxidative decomposition of dissolved odorous substances be performed in the liquid phase of the aerobic treatment tank, but also the space portion (in the gas phase) within the sewage septic tank is not dissolved. The odorous substance can be oxidatively decomposed by ozone released to the part. Furthermore, by circulating ozone-dissolved water to the anaerobic treatment tank 21, it is possible to prevent the oxidation-reduction potential of the anaerobic treatment tank 21 from being lowered and to suppress the generation of odorous substances typified by hydrogen sulfide.

  ADVANTAGE OF THE INVENTION According to this invention, not only a dissolved odor substance can be decomposed | disassembled in the liquid phase of an aerobic treatment tank, but an odor substance can be decomposed | disassembled also in the space part (in gaseous phase) in a sewage purification tank. Further, by circulating ozone-dissolved water to the anaerobic treatment tank, it is possible to prevent the reduction of the oxidation-reduction potential of the anaerobic treatment tank and suppress the production of malodorous substances, so that deodorization can be performed effectively.

  Furthermore, when a deodorizing catalyst is provided in a portion of the space in the tank, the deodorizing efficiency can be further improved, and excess ozone can be decomposed to prevent ozone from leaking out of the septic tank. It can also contribute to the decolorization of treated water and the foaming suppression effect in the initial operation.

Hereinafter, with reference to drawings, the example of the deodorizing method of the sewage septic tank of the present invention and the sewage septic tank is described.
FIG. 1 is a schematic sectional view showing one embodiment of the sewage septic tank of the present invention. First, the structure will be described. The septic tank is provided with an anaerobic treatment tank first chamber 21, an anaerobic treatment tank second chamber 22, an aerobic treatment tank 30, a treated water tank (precipitation tank) 40, and a disinfection tank 33.

  The shape of the filter bed 23 provided in the anaerobic treatment tanks 21 and 22 is not particularly limited, and plate-like members such as loofah-like, corrugated and porous, honeycomb-like (honeycomb core) members, etc. Preferably used. Skeletal spherical, mesh-like cylindrical members and the like can also be used. The filter bed 23 may be provided only in the anaerobic filter bed tank second chamber 22, or may be removed from both the anaerobic filter bed tank first chamber 21 and the anaerobic filter bed tank second chamber 22.

  The aerobic treatment tank 30 is provided with a biological reaction bed 9a and a diffuser member 11 for biological reaction below the biological reaction bed 9a. In addition, an air lift pump 31 for transferring the liquid processed in the aerobic treatment tank 30 to the anaerobic treatment tank first chamber 21 is provided on the downstream side of the aerobic treatment tank 30.

  The biological reaction bed 9a is filled with a filter medium (microorganism carrier, microorganism adhesion material, contact material) to which microorganisms for aerobically treating organic substances in the influent are adhered. The biological reaction bed 9a may be a fluidized bed or a fixed bed.

  The shape of the filter medium can be various shapes such as plate, net plate, loofah, porous, cylinder, rod, skeleton sphere, string, and granular, irregular lump, cube, and fiber lump. What was processed can be used. Examples of the base material include synthetic resin processed products such as polyvinyl chloride, polyester, polyvinylidene chloride, polyvinyl formal, polyurethane, and melamine resin, inorganic processed products such as ceramics and silica sand, and fossils such as anthracite. A processed product, activated carbon or the like having a specific gravity of about 1 or 1 or more, a polyolefin resin such as polyethylene or polypropylene, or a specific gravity of about 1 or 1 or less such as polystyrene can be used.

  In the present embodiment, the ozone generator 7 is disposed in the middle of the air pipe 15 that connects the air diffuser 11 and the air lift pump 31 provided in the aerobic treatment tank 30 and the blower 35. As a result, the ozone-containing air is discharged from the diffuser member 11, and the ozone-containing air is also sent to the air lift pump 31, and ozone dissolved water generated by dissolving ozone in the circulating water 42 in the air lift pump 31 is anaerobic treatment tank. Circulate to the first chamber 21. The ozone dissolved in the circulating water 42 may be immediately decomposed into dissolved oxygen, but a higher oxygen concentration is obtained than when air is simply used. Therefore, the oxidation of the first chamber 21 in the anaerobic treatment tank 21 is performed. A reduction in reduction potential can be prevented.

  In the embodiment shown in FIG. 1, the circulating water 42 is returned to one place in the anaerobic treatment tank first chamber 21, but the circulation pipe 17 is branched or a hole is made in the middle of the circulation pipe 17. Alternatively, water may be sprayed from a plurality of locations above the anaerobic treatment tanks 21 and 22. If it does in this way, since the area and time which contact ozone dissolved water with the odorous substance which exists in a sewage septic tank space part increase, deodorization can be performed more effectively.

  The ozone concentration supplied from the ozone generator 7 is usually 10 to 100 ppm, preferably 30 to 60 ppm. When the concentration is within this range, the odorous substance in the liquid can be oxidatively decomposed without adversely affecting the microorganisms. In addition, since the ozone concentration in the space in the tank can be maintained at about 0.5 to 5 ppm, the odorous substance can be effectively decomposed in the gas phase. In addition, supply of ozone can be performed continuously or intermittently according to the inflow pattern in the inflowing sewage, the organic substance concentration, or the like, or the ozone concentration can be changed.

FIG. 2 is a schematic sectional view of a sewage septic tank showing another embodiment of the present invention.
The sewage purification tank includes an anaerobic treatment tank first chamber 21, an anaerobic treatment tank second chamber 22, an aerobic treatment tank 30, a treated water tank (precipitation tank) 40, and a disinfection tank 33.

  The aerobic treatment tank 30 includes a biological reaction chamber 9 in the upper portion and a filtration chamber 10 in the lower portion. In the sewage septic tank shown in FIG. 2, the biological reaction chamber 9 and the filtration chamber 10 are arranged up and down, but the positional relationship between the two chambers is not limited to this and may be arranged in the horizontal direction.

  A filtration bed 10a filled with a filter medium is formed in the filtration chamber 10 to capture and remove SS in the influent. As the filter medium to be filled, one that floats in the liquid can be used, but a sedimentation filter medium is preferable. Examples of sedimentary filter media include synthetic resin processed products such as polyvinyl chloride, polyester, polyvinylidene chloride, polyvinyl formal, polyurethane, and melamine resin, inorganic processed products such as ceramics and quartz sand, and fossil processing such as anthracite. Products, activated carbon, etc., with specific gravity of about 1 or more, or polyolefin resin such as polyethylene, polypropylene, etc., and those with a specific gravity of about 1 or more adjusted by adding fillers to polystyrene. It may be formed and processed into a lump shape, a cylindrical shape, a net shape, a rod shape, a fiber lump shape, or a porous shape.

  Below the filter bed 10a, the cleaning air diffuser 12 for cleaning the filter bed 10a and the cleaning waste water 4 generated when the SS captured by the filter bed 10a is peeled off are put in the anaerobic treatment tank first chamber 21. A cleaning drainage pump 14 for transfer is provided.

  The cleaning air diffusion member 12 and the cleaning drainage pump 14 are connected to the blower 35 via the flow path switching device 13 by the air pipe 16. The flow path switching device 13 is a device that switches the air sent from the blower 35 to one of the air pipes 15 and 16, and can use an electromagnetic valve, a switching valve, and the like. In this embodiment, a timer is used. A switching valve that can be switched automatically is used. During normal operation of the septic tank, the air from the blower 35 is set to be sent to the air pipe 15, but at the time set by the timer (during the washing operation), the flow path is switched to the air pipe 16 and the filter bed 10a is set. Wash.

  In the case of such a sewage septic tank, it is preferable that the ozone generator 7 is turned on when air is flowing through the air pipe 15. As this means, the ozone generator 7 is powered on by the flow path switching device 13. Or a wind pressure sensor near the entrance of the ozone generator 7 so that the ozone generator 7 can be turned off when the wind pressure falls below a set value.

  FIG. 3 is a schematic cross-sectional view showing an embodiment of a sewage septic tank in which a deodorizing catalyst 19 is provided in a part of the sewage septic tank. 3 is the same as FIG. 2 except that the deodorizing catalyst 19 is installed.

  The deodorization catalyst 19 includes any one of oxides or salts such as Ti, Si, Zr, Mn, Fe, Zn, Ni, Co, Al, Ag, Pt, Pd, and Rh, or a combination thereof. Can be used. In addition, natural minerals such as zeolite, montmorillonite, allophane, imogolite, diatomaceous earth, etc., and carbon materials such as charcoal, activated carbon, carbon fiber, and the like, Ti, Si, Zr, Mn, Fe, Zn, Ni, Co, You may use what carry | supported at least one of oxides or salts, such as Al, Ag, Pt, Pd, and Rh.

  The deodorizing catalyst 19 may be installed anywhere as long as it is a space in the sewage septic tank, that is, a position higher than the surface of the treated water, but more specifically near the lower portion of each manhole 39, more specifically. And fixed to the back of the manhole cover. If provided below the manhole 39, before undecomposed ozone and odorous substances leak from the manhole 39, they can be reacted and decomposed. In addition to preventing the surface of the deodorizing catalyst 19 from becoming dirty due to scattering of the liquid in the tank and reducing the catalytic effect, the work for replacing the deodorizing catalyst 19 is also easy.

  Hereinafter, the treatment of sewage will be described. The sewage enters the anaerobic treatment tank first chamber 21 from the sewage inflow port 20, and the solid matter in the influent sewage is separated and anaerobic treatment is performed. The advection liquid from the anaerobic treatment tank first chamber 21 enters the anaerobic treatment tank second chamber 22 where further solids separation and anaerobic treatment are performed.

  The advection liquid from the anaerobic treatment tank second chamber 22 enters the aerobic treatment tank 30, and in the biological reaction chamber 9, the organic matter in the advection liquid from the anaerobic treatment tank second chamber 22 is aerobically biodegraded and generated. The collected SS is captured and filtered in the filtration chamber 10.

  The filter bed 10a is clogged due to accumulation of SS over time, and is thus periodically or appropriately (reversely) washed. In this cleaning, the air of the blower 35 is discharged from the cleaning air diffuser 12 to bubble the filtration bed 10a, and a part of the air of the blower 35 is also supplied to the cleaning drainage pump (air lift pump) 14. The peeled SS becomes cleaning wastewater together with the liquid in the tank, descends the filtration bed 10a, returns to the first chamber 21 of the anaerobic processing tank through the cleaning drainage discharge member 14a by the cleaning drainage pump 14. Cleaning of the filter bed 10a is usually preferably performed at midnight when sewage is rarely discharged in a general household. The advection liquid from the aerobic treatment tank 30 passes through the treatment water tank 40, enters the disinfection tank 33, is in contact with the medicine cylinder 38 and is disinfected, and is then discharged from the discharge port 41 as treated water.

It is a schematic sectional drawing which shows an example of the sewage septic tank which is the Example of this invention. It is a schematic sectional drawing which shows an example of the sewage septic tank which is the other Example of this invention. It is a schematic sectional drawing which shows an example of the sewage septic tank which is further another Example of this invention. It is a schematic sectional drawing which shows the sewage septic tank which is a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 ... Influent, 7 ... Ozone generator, 9 ... Biological reaction chamber, 9a ... Biological reaction bed, 10 ... Filtration chamber, 10a ... Filtration bed, 11 ... (For reaction) Aeration member, 12 ... Cleaning aeration member , 13 ... flow path switching device, 14 ... cleaning drainage pump, 14a ... cleaning drainage discharge member, 15 ... air pipe, 16 ... air pipe, 17 ... circulation pipe, 19 ... deodorization catalyst, 20 ... sewage inlet, 21 ... Anaerobic treatment tank 1st chamber, 22 ... Anaerobic treatment tank 2nd chamber, 23 ... Filter bed, 30 ... Aerobic treatment tank, 31 ... Air lift pump, 33 ... Disinfection tank, 35 ... Blower, 38 ... Medicine bottle, 39 ... Manhole 40 ... treated water tank, 41 ... outlet, 42 ... circulating water, 50 ... ozone supply pipe, 51 ... treatment chamber

Claims (3)

  An anaerobic treatment tank, an aerobic treatment tank having an aeration member, and an air lift pump for circulating a part of the liquid in the aerobic treatment tank to the anaerobic treatment tank, to the aeration member and the air lift pump A sewage septic tank with an ozone generator in the middle of an air supply pipe that supplies air.   The sewage septic tank according to claim 1, further comprising a deodorizing catalyst in a position higher than the surface of the treated water in the sewage septic tank. An anaerobic treatment tank, an aerobic treatment tank having an aeration member, and an air lift pump for circulating a part of the liquid in the aerobic treatment tank to the anaerobic treatment tank, A method for deodorizing a sewage septic tank, wherein the air supplied to the air diffuser and the air lift pump is ozone-containing air.

Images