JPH11169897A - Bonus based pellet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a humus based pellet capable of easily and precisely recognizing the wear state and executing the replenisheant or the like to a sludge contact vessel by bulk charge or the like. SOLUTION: The humus pellet P is formed into a size to have a specific gravity of 0.95 as a whole and to be charged in a bulk state by providing in layers a main material Pb prepared by blending a powdery iron, a magnesium compound, a cellulose and a chitin in the humus soil on the outer circumference of a cylindrical sub-material Pa such as wood having a specific gravity of <=1. And at the time of treating a sludge or the like, the humus based pellet P is charged in bulk to the sludge contact vessel and the wear state is recognized from a charging port or the like by visual observation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to humus pellets used for biological treatment of sewage and sludge, and more specifically, humic pellets having a specific gravity smaller than that of sewage and sludge and of a size that can be put into a sludge contact tank in bulk. The present invention relates to humic pellets that can easily confirm the depletion state and facilitate the management of the timing of replenishment.

[0002]

2. Description of the Related Art Generally, a biological treatment tank, such as a biological treatment tank combining an anaerobic filter tank and an aerobic filter tank, or a batch tank, is often used for treating organic wastewater such as agricultural settlement drainage. . In the biological treatment of such organic wastewater, the emission of offensive odors contained in the organic wastewater itself and the generation of offensive odors due to the anaerobic decomposition of sludge generated in the treatment system during the retention. As a result, the odor generated in each tank was considerably strong, resulting in deterioration of the working environment.

[0003] In order to prevent odors, various techniques have been developed to prevent and deodorize odors from sewage and sludge in a liquid state while treating organic sewage such as agricultural settlement drainage. (Referred to as prior art for convenience). In this prior art, organic sewage is mixed and treated with a culture solution cultured using humus soil in a pretreatment step, and then the sewage is subjected to anaerobic filtration in an anaerobic filter tank and subsequently to an aerobic filter. It is treated with aerobic microorganisms in a tank, after which it is guided to a sedimentation tank to settle sludge, and then disinfected and discharged.

Further, sludge generated in the anaerobic filter bed tank or the sedimentation tank is led to a concentrated sludge storage tank and concentrated, and the sludge is circulated between the concentrated sludge storage tank and the sludge contact tank. Is brought into contact with the humic pellets to perform an aeration process to perform an oxidation reaction and the growth of microorganisms. Then, a part of the treated sludge in the concentrated sludge storage tank is returned to the pretreatment step as circulating sludge, and the remaining sludge is dehydrated by a dehydrator after adding a flocculant and the like.

The above-mentioned sludge contact tank generally has an inflow pipe connected to the upper part of the tank, an outflow pipe connected to the lower part of the tank, and a detachable cartridge filled with humic pellets in the tank. The air diffusion pump has an air lift pump communicating the lower part and the upper part in the tank. In this sludge contact tank, the sludge flowing from the inflow pipe is circulated by an air lift pump and brought into contact with the humic pellets in the cartridge. Then, since the humic pellets are depleted with the treatment of the sludge, when the humic pellets are depleted, the cartridge is taken out of the tank and replaced.

[0006]

However, in the above-mentioned humic pellets, the cartridge must be pulled out from the tank in order to check the depleted state, and the work of checking the depleted state is complicated. was there. The present invention has been made in view of the above problems, and an object of the present invention is to provide a humic pellet capable of easily confirming a depleted state.

[0007]

In order to achieve the above object, a humic pellet according to the present invention is obtained by blending at least the present material containing humus with a sub-material having a specific gravity of less than 1.
It is formed into a size that can be put into the sludge contact tank at a specific gravity of less than the specific gravity.

[0008] The humus pellets according to the present invention may be formed in a form (claim 2) in which the present material and the sub-material are mixed and formed. (Claim 3), further comprising a wood-based material as the auxiliary material (Claim 4).

The humic pellets are put into a sludge contact tank at the time of treatment of sewage and sludge, for example, treatment of sludge generated by treatment of organic sewage. The sludge contact tank is
Usually, it is used in combination with a sludge circulation tank or a sludge receiving tank.

The humic pellets are formed by extruding the powdery material with the auxiliary material by extrusion molding or the like using an extruder or the like. For example, the auxiliary material is formed at the center, and the layer of the material is formed outside the auxiliary material. Or by laminating a layer of this material and a layer of sub-materials, or by mixing and molding this material and sub-materials. It is further formed to have a specific gravity of less than 1 and desirably about 0.95 so that it can be separated from sludge or the like by a screen or the like to prevent outflow.

As the material, humus alone or a humus to which a magnesium compound, iron, cellulose, chitin or the like is added as necessary is used. Humus soil is a soil rich in humic and fulvic acids.
The magnesium compound generates magnesium ions, and examples thereof include magnesium hydroxide and magnesium carbonate. The magnesium compound is blended as magnesium ions at a ratio of 1 to 3%. As iron, iron hydroxide, iron oxide, or the like is used in addition to iron alone. Cellulose is a commercially available powder, and chitin is a commercially available powder. This material is usually adjusted to a specific gravity of about 1.0 to 1.1 g / ml.

The secondary material has a specific gravity of less than 1, for example,
Resin such as styrofoam or wood-based material such as wood chips and sawdust is used. As described above, it is used alone or in a powder form and mixed with the present material.

[0013]

The humic pellets according to the present invention are put into a sludge contact tank in bulk together with sludge and the like, and diffused and stirred in the sludge contact tank to perform an oxidation reaction on the sludge and the growth of aerobic microorganisms. Since the humic pellets can be visually checked for depletion through a viewing window or the like provided in the sludge contact tank, the replenishment timing and the like can be easily and accurately determined without interrupting the treatment.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 3 show a humus pellet according to an embodiment of the present invention. FIG. 1 is a schematic diagram of the humus pellet, and FIG. 2 is a sewage treatment apparatus for treating sludge using the humus pellet. FIG. 3 is a schematic sectional view of a sludge contact tank used in the wastewater treatment apparatus.

First, referring to FIG.
Explaining, the humus pellet P has a columnar shape as a whole and has a specific gravity of about 0.95. The humic pellet P has a columnar sub-material layer Pa at the center and a main material layer Pb integrally fixed to the outer periphery of the sub-material layer Pa, and the sub-material layer Pa is a sludge contact tank described later. Has a size that cannot pass through the screen. The auxiliary material layer Pa is a material having a specific gravity of less than 1, for example, a piece of wood having a specific gravity of about 0.5, and the material layer Pb is a humus alone or a powdery magnesium compound, , Cellulose, chitin and the like are molded. This material layer Pb has a specific gravity of about 1.05.

The humic material pellet P is not limited to the shape shown in FIG. 1a, but is entirely formed into a rectangular flat plate as shown in FIG. 1b, that is, the plate-shaped sub-material layer Pa and the main material layer Pb are laminated. Alternatively, as shown in FIG. 1c, it is also possible to use sawdust or the like as a secondary material and mix it with humus or the like, which is the present material, to form a uniform cylindrical shape. The humic pellets P in FIG.
to a size that a cannot pass through the screen,
The humic pellet P of FIG. 1c is formed in a size that cannot be entirely passed through the screen.

Next, a wastewater treatment apparatus using the humic pellets P will be described with reference to FIG. In FIG. 2, 1
Reference numeral 0 denotes a sewage treatment system, reference numeral 20 denotes a sludge treatment system, and reference numeral 10 denotes a sewage treatment system.
3, a sedimentation tank 14 and a disinfection tank 15, and a sludge treatment system 20 includes a sludge receiving tank 21, a sludge circulation tank 22, a sludge contact tank 23, a separation liquid tank 24, a mixing tank 25, and a flocculant dissolution storage tank 2.
6 and a dehydrator 27.

The pretreatment tank 11 is provided with an aeration sedimentation tank for aerating sewage, a raw water pump tank, a crusher, a coarse screen, a fine screen, a sand discharge pump, and the like. In this pretreatment tank, a separating liquid or a desorbing liquid containing humic substances, which will be described later, is added to the inflowing wastewater, mixed, guided through a coarse screen into an aeration sand settling tank, and aerated in the aerated sand settling tank. Then, the treated sewage is crushed by a crusher after passing through a fine screen, guided to the raw water pump tank, and the sewage in the raw water pump tank is sent to the flow rate adjusting tank 12. The flow rate adjusting tank 12 temporarily stores the sewage and sends out a specified amount of sewage to the biological treatment tank 13.

The biological treatment tank 13 is a well-known one.
Typical examples include a batch tank, an anaerobic filter tank and an aerobic filter tank connected in series. The former biological treatment tank 1
Reference numeral 3 executes a well-known treatment cycle such as aeration and agitation in the batch tank to treat the sewage, and sends out the sludge settled and separated in the batch tank to the sludge receiving tank 21. The latter biological treatment tank 13
The sewage is guided from the flow control tank 12 to the anaerobic filter tank, and the biological treatment of the sewage by anaerobic microorganisms is performed in the anaerobic filter tank.
Subsequently, the aerobic filter bed is subjected to aeration and agitation to perform biological treatment with aerobic microorganisms, and the sludge settled in the anaerobic filter tank is sent to the sludge receiving tank 21.

The sedimentation tank 14 receives the sewage from the biological treatment tank 13, sediments and separates the sludge from the sewage, and sends the treated water as the supernatant water to the disinfection tank 15 and the sedimentation sludge to the sludge receiving tank 21. The disinfection tank 15 disinfects the treated water flowing from the sedimentation tank 14 by adding a disinfectant or the like, and discharges the disinfected treated water.

In the sludge receiving tank 21, sludge flows in from the biological treatment tank 13 and the sludge sedimentation tank 14, and sludge flows in from the sludge circulation tank 22, and the sludge is stirred by air to control the concentration and promote the biological reaction. The preparation of acclimatized sludge and the uniformization of sludge concentration are performed. The sludge circulation tank 22 receives the uniformized sludge from the sludge receiving tank 21, circulates the sludge between the sludge receiving tank 21 and the sludge contact tank 23, and diffuses air to sufficiently culture the microorganisms. Is sent to the separation liquid tank 24, and excess sludge is sent to the mixing tank 25. The separation liquid tank 24 sediments the separation liquid containing humus from the sludge and sends it to the pretreatment tank 11, that is, separates the separation liquid containing humus obtained as a supernatant by subjecting the sludge to a pretreatment tank. 11 to help control odor in the pretreatment tank 11.

As shown in FIG. 3, the sludge contact tank 23 has an inlet 31a in which the tank body 31 can be opened and closed by a lid 39 at the upper part.
The upper part of the tank body 31 communicates with the sludge circulation tank 22 through the sludge inflow pipe 32, and the lower part of the tank body 31 through the sludge discharge pipe 33. Inside the tank main body 31, a screen 34 for preventing humic pellets from flowing out is provided at a lower portion, an air diffuser 35 is provided on the screen 34, and an air lift pump 36 is provided. The air diffuser 35 and the air lift pump 36 are provided with a blower (not shown). Contact In the sludge contact tank 23, the sludge flows into the tank main body 31 via the sludge inflow pipe 32, the humic pellets P are charged into the sludge in the tank main body 31 from the input port 31a, and the sludge and the humic pellet are mixed. The treatment sludge is circulated and oxidized as the main treatment, and the aerobic microorganisms are propagated.
Return to.

The mixing tank 25 receives the sludge sent from the sludge circulation tank 22 by a sludge transfer pump or the like and the flocculant supplied from the flocculant dissolution storage tank 26 by a flocculant supply pump or the like, and mixes the flocculant with the sludge. To make the sludge floc,
The floc sludge is sent to the dehydrator 27. Dehydrator 2
Reference numeral 7 dehydrates the sludge flocculated in the mixing tank 25 to obtain a dewatered cake which is easy to handle and can be reused as a soil conditioner or the like. This dehydrator 27 is a belt press type,
Various types such as a vacuum type, a centrifugal type, and a screw dehydrator can be used. It is desirable to use a multi-plate outer shell type screw dehydrator equipped with a vessel.

In this embodiment, the pretreatment tank 11
In step (1), a separation liquid containing humus and a separation liquid containing humus, which are returned from the separation liquid tank 24, are introduced into the organic sludge, and the sludge is introduced into the biological treatment tank 13 so that the wastewater undergoes a biological reaction to be treated. At the same time, the sludge is settled and separated from the wastewater in the sedimentation tank 14, and the treated water is disinfected in the disinfection tank 15 and discharged.
The sludge settled and separated in the settling tank 14 and the like is sent to the sludge receiving tank 40. That is, in the case of the biological treatment tank 13 having a batch tank, a series of well-known steps such as aeration and agitation and settling and separation of sludge are repeatedly performed in the batch tank to treat sewage, and the sludge is sent to the sludge receiving tank 21; If the biological treatment tank 13 has an anaerobic filter tank and an aerobic filter tank, the biological reaction by anaerobic microorganisms in the anaerobic filter tank and the biological reaction by aerobic microorganisms in the aerobic filter tank are sewage. The sludge settled and separated is sent out to the sludge receiving tank 21.

In the sludge receiving tank 21, the received sludge is mixed with the conditioned sludge sent from the sludge circulation tank 22 by air stirring and mixing to perform homogenization and concentration adjustment of the sludge as a pretreatment, and to perform oxidation reduction of the sludge. When the potential Eh becomes -50 mV or more, it is sent out to the sludge circulation tank 22. That is, in the sludge receiving tank 21, the treated sludge is received from the sludge circulation tank 22, the treated sludge is mixed with the sludge sent from the biological treatment tank 13, and the concentration and quality of the sludge sent to the sludge circulation tank 22 are determined. Make it uniform.

In the sludge circulation tank 22, the sludge is transferred to and from the sludge contact tank 23, and the sludge subjected to biological treatment in the sludge contact tank 23 is mixed and diffused with the sludge received from the sludge receiving tank 21, To make the quality and concentration of sludge uniform. Further, in the sludge contact tank 23, humic pellets P are dispensed through the inlet 31a, and the sludge is circulated through the tank by the air lift pump 36 for a predetermined time to diffuse and contact with the humic pellets. Cause a biological reaction. Here, since the humic pellets P can be dispensed through the inspection port 31a, replenishment is easy, and the degree of depletion is also reduced.
The determination can be made by observing the humus pellets P floating on the sludge by looking into the inside from 1a, and the replenishment time of the humus pellets P can be accurately determined. That is, since the humic pellet P has a specific gravity smaller than 1 and tends to rise from the sludge, it is possible to obtain a measure of replenishment by observing the state of floating on the sludge.

The humic pellets include not only humus soil but also iron (compound), magnesium compound, cellulose,
Since it also contains chitin, Bacillus and actinomycetes in the sludge can be preferentially grown, and phosphorus is mostly contained on the sludge side. Therefore, as described below, this sludge is
It is useful as a soil conditioner and fertilizer, can reuse sludge, and when dewatering sludge, phosphorus is not released together with desorbed liquid, preventing eutrophication of rivers that discharge treated water. it can.

In the sludge circulation tank 22, sludge is transferred to and from the separation liquid tank 24, the separation liquid containing humus is separated from the sludge in the separation liquid tank 24, and returned to the pretreatment tank 11. When the storage amount of the sludge is equal to or more than a predetermined amount and the oxidation-reduction potential and concentration of the sludge are equal to or more than a predetermined value, the sludge is sent to the mixing tank 25. Then, in the mixing tank 25, the flocculant supplied from the flocculant dissolution storage tank 26 is added to the sludge to floc the sludge, and the floc sludge is guided to the dehydrator 27 to be dewatered. In the dehydrator 27, the sludge is dewatered into a dewatered cake, and the desorbed liquid separated from the sludge is returned to the pretreatment tank 11.

Here, the dewatered cake is treated by bringing sludge into contact with the iron-containing humic pellets in the sludge contact tank 23. Since the sludge contains iron, phosphorus is ingested into the sludge as iron phosphate, and phosphorus is absorbed. Is useful as a fertilizer. In the sludge contact tank 23, sludge is an iron compound,
Since it is treated with humic pellets containing magnesium compounds, cellulose and chicken, Bacillus bacteria and actinomycetes dominantly propagate in the sludge, and these Bacillus bacteria and actinomycetes dehydrate the sludge and dehydrate the cake. After that, the spores survive in the dehydrated cake. Therefore, this dehydrated cake is also useful as a soil conditioner for killing soil pathogenic bacteria, and sludge can be effectively reused. In other words, when the dehydrated cake is sprayed on arable land, spore-forming actinomycetes and bacilli are activated. Since cell membranes such as iron and picium lyse cellulosic soil-borne pathogens, they are also effective as soil conditioners.

[0031]

As described above, according to the humic pellets of the present invention, the specific gravity of the material containing humus is 1%.
Less than a sub-material is blended and formed into a size that can be loosely loaded into the treatment tank with a specific gravity of less than 1, so it can be easily refilled into the sludge contact tank and the depleted state in the sludge contact tank Judgments can be made easily and accurately, and replenishment can be made at an appropriate time.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a humic pellet according to one embodiment of the present invention, in which a, b, and c show different modes, respectively.

FIG. 2 is a block diagram of a sewage treatment apparatus using the humic pellets.

FIG. 3 is a schematic sectional view of a sludge contact tank of the wastewater treatment apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Sewage treatment system 11 Pretreatment tank 13 Biological treatment tank 20 Sludge treatment system 21 Sludge receiving tank 22 Sludge circulation tank 23 Sludge contact tank 24 Separation liquid tank 27 Dehydrator 31 Tank body 31a Input port

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tokuaki Itoi 1-10-14 Hamamatsucho, Minato-ku, Tokyo Sumitomo Higashi Shimbashi Building No. 3 In the Japan Agricultural Village Drainage Association (72) Inventor Hiroshi Kawashige Tokyo 1-10-14, Hamamatsucho, Minato-ku Sumitomo Higashi Shimbashi Building No. 3 Inside the Japan Agricultural Village Drainage Association (72) Inventor Takayuki Kata 1-27-27 Konan, Minato-ku, Tokyo Inside Ebara Corporation (72 ) Inventor Akira Ichihara 1-6-27 Konan, Minato-ku, Tokyo Inside Ebara Manufacturing Co., Ltd. (72) Inventor Kunitake Suzuki 7-14-1 Ginza, Chuo-ku, Tokyo Inside Ebara Corporation (72) Invention Person Mashiro Ishikawa 7-14-1 Ginza, Chuo-ku, Tokyo Inside Ebara Corporation

Claims (4)

[Claims] 1. A material having a specific gravity of less than 1 is blended with the present material containing at least humus soil, and the material is formed into a size that can be loosely loaded into a sludge contact tank with a specific gravity of less than 1. Humic pellets. 2. The humic pellet according to claim 1, wherein the material is mixed with the auxiliary material. 3. The humus pellet according to claim 1, wherein the material comprises only humus or humus, a magnesium compound, iron, cellulose, and chitin. 4. The humic pellet according to claim 1, wherein said auxiliary material is a wood-based material.