JP2000271595A - Method for preventing clogging of pipeline with map particle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the clogging of a pipeline with Mg(NH4)PO4 (MAP) particles by preliminarily removing an MAP particle generating main cause component bringing about trouble such as the clogging of the pipeline caused by the adhesion of MAP particles. SOLUTION: An aeration device 6 is provided on the upstream side of a pipeline 5 for transporting sludge and sludge is preliminarily aerated in the aeration device 6 to form Mg(NH4)PO4 (MAP) particles in sludge and an MAP particle generating main cause component, that is, phosphate ions or magnesium ions are removed before sludge is sent into the pipeline 5. Since the concn. of the MAP particle generating main cause component in sludge is reduced by this constitution, a fear such that MAP particles adhere to the inner wall of the pipeline 5 to bring about trouble such clogging can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, when sludge generated from a sewage treatment facility or the like is transported to a sludge treatment facility via a pipeline, the sludge adheres to the pipeline and causes trouble such as blockage. The present invention relates to a method for preventing pipeline blockage by MAP particles that may be involved.

[0002]

2. Description of the Related Art Generally, in a pipeline for transporting sludge generated in a sewage treatment facility to a sludge treatment facility or the like, a so-called MAP in which magnesium ions and phosphoric acid in the sewage are combined. Particles (Magnesium-Am
Monium-Phosphate: A precipitate referred to as Mg (NH ₄ ) PO ₄ ) often occurs. Mg ²⁺ , NH ₄ ⁺ , and PO ₄ ^{3- which} cause MAP particle precipitation exist in a form dissolved in sludge, and since the solubility of the MAP particles in water of the compound is not so large, sludge etc. When transported to a sludge treatment facility or the like via a pipeline, MAP particles adhere to the pipeline inner wall and reduce the diameter of the pipeline. In the worst case, there is a possibility that the pipeline will eventually be blocked. .

Therefore, when such a phenomenon occurs, conventionally, the inside of the pipeline is periodically cleaned to remove MAP particles attached to the inner wall by human naval tactics, or the pipeline itself is renewed. It is necessary to perform work such as replacement.

[0004] However, such cleaning work and replacement work in the pipeline require a great deal of labor and cost, and during these works, the operation of the sewage treatment equipment provided with the work is temporarily stopped. There is a problem that must be done. In addition, when the sewage treatment equipment and the sludge treatment equipment are separated from each other and the pipes are long, this problem becomes more remarkable.

Accordingly, the present invention has been devised to effectively solve such a problem, and an object of the present invention is to provide an M.sub.M which is likely to adhere to a pipe and cause troubles such as blockage.
An object of the present invention is to provide a method for preventing the MAP particles from obstructing the inside of the duct by removing AP factor forming factors, particularly phosphate ions, in advance.

[0006]

According to the present invention, there is provided an aeration apparatus upstream of a pipe for transporting sludge, wherein the sludge is aerated in advance in the aeration apparatus. The MAP particles are formed therein to remove the MAP particle formation factor component from the pore water of the sludge, and then the sludge is sent into the pipe.

That is, when the sludge before transportation is aerated in the aeration apparatus, CO ₂ dissolved in the sludge is volatilized and the pH of the sludge is increased, and the amount of MA contained in the sludge is increased.
P-particle forming factors, such as phosphoric acid and magnesium ions, are chemically bonded to form MAP in the aeration apparatus.
Particles are formed. Then, since the concentration of the MAP particle formation factor component is low in the sludge after such MAP particles are formed, MAP particles are generated in the pipeline even if the sludge is allowed to flow into the pipeline as it is. Never do.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a method of preventing pipeline blockage using MAP particles according to the present invention. In FIG. 1, reference numeral 1 denotes a sewage treatment facility for collecting and treating sewage from homes and the like. Is a sludge storage tank provided in this sewage treatment facility 1,
Reference numeral 3 denotes a sludge treatment facility constructed at a position away from the sewage treatment facility 1. Reference numeral 4 denotes a sludge receiving tank provided in the sludge treatment facility 3. Reference numeral 5 denotes a sludge receiving tank provided in the sludge storage tank 2. A mud pipe (pipe) for direct transport, 6 is a mud pipe 5
, That is, an aeration device provided near the downstream side of the sludge storage tank 2.

As shown in FIG. 2, for example, the aeration apparatus 6 is provided with an introduction line 8 for introducing sludge and an aeration line 9 for blowing air for aeration at the bottom of a vertical container 7 having an open top. A discharge line 1 for overflowing and discharging sludge into the upper part of the vertical container 7
As shown in the drawing, MAP particles are generated by blowing air from the aeration line 9 into the sludge introduced into the vertical container 7 from the introduction line 8 to aerate the sludge. The configuration is such that the later sludge is sent from the discharge line 10 to the mud pipe 5 side together with the MAP particles.

Accordingly, as shown in the figure, the sludge generated in the sewage treatment facility 1 is temporarily stored in the sludge storage tank 2 and then batchwise or continuously.
, Where it is aerated for a predetermined time. Then, the CO ₂ is vaporized that Yoson in the sludge, H ^{+ +} HCO ^- ₃
→ As the reaction of H ₂ O + CO ₂ progresses, the pH of the sludge increases, and as a result, MAP particles (Mg (NH ₄ ) PO having an average particle size of about several hundred μm to several mm are contained in the sludge.
₄ ) is formed. As a result, the concentrations of phosphate and magnesium ions, which are components of the MAP particle formation factor dissolved in the sludge, are significantly reduced.

The sludge whose phosphoric acid or magnesium ion concentration has been significantly reduced flows out from the discharge line 10 together with the precipitated MAP particles, and is sent to the mud pipe 5 so that the MAP particles in the mud pipe 5 are removed. And inconveniences such as blockage due to the adhesion can be effectively avoided. Further, by sending the MAP particles to the mud pipe 5 side, the flow of the MAP particles can also be prevented from adhering to the inner wall of the mud pipe 5, thereby further increasing the safety. As a result, the cleaning and replacement of the inside of the sludge pipe 5 as in the related art becomes unnecessary, and the labor and cost required for this work can be reduced.

Next, as a second embodiment of the present invention,
As shown in FIG. 1, a MAP reactor 12 is used instead of the aeration device 6 used in the above-described first embodiment.
It is provided with.

Although various types of the MAP reactor 12 have been proposed, for example, the type shown in FIG. 3 can be used. That is, the MAP reactor 12 connects the introduction line 8 for introducing sludge to the bottom of the vertical container 13 and the aeration line 9, and forms a MAP particle by performing aeration while flowing sludge in an upward flow. The same as the device 6, but in this case, an umbrella-shaped separator 14a for collecting air on the way is provided,
Above this, a precipitation part 15 is formed.
Therefore, the aerated air is supplied to the umbrella-shaped separator 14.
Because it is no longer raised after being collected in a,
The MAP particles that have reached the sedimentation section 15 thereabove do not settle out of the vertical container 13 due to their own weight and flow out.

Therefore, such an aeration apparatus 6
By providing such a MAP reactor 12 in place of, the formed MAP particles can be selected and concentrated in the MAP reactor. Note that, in order to further ensure the separation of the MAP particles, another separator 14b may be added above the settling portion 15.

Next, FIG. 4 shows a third embodiment of the present invention. An anaerobic digestion tank 16 is added upstream of the aeration apparatus 6 or the MAP reactor 12 described above. The sludge before being introduced into the aeration apparatus 6 or the MAP reactor 12 is anaerobically treated by anaerobic microorganisms in the digestion tank 16.
This will increase the alkalinity in the sludge,
After the CO ₂ concentration increases, the aeration device 6 or M
Introduced into the AP reactor 12, where p
Since H further increases and the generation rate of MAP particles increases, the concentration of the MAP particle forming factor component remaining in the sludge can be further reduced.

FIG. 5 shows a fourth embodiment of the present invention. A plurality of suction plates 18 as shown in FIG. 6 are provided downstream of the aeration apparatus 6 or the MAP reactor 12 described above. Are provided in parallel with each other, and sludge is allowed to pass through the adsorption tank 17 while being brought into contact with the adsorption tank 17 before being sent to the mud feed pipe 5 side. Thereby, the MAP particles that cannot be completely removed by the aeration apparatus 6 or the MAP reactor 12 or the MAP particles generated immediately after flowing out of the aeration apparatus 6 or the MAP reactor 12 can be removed by adsorbing on the adsorption plate 18. . The number and shape of the adsorbing plates 18 of the adsorbing tank 17 are not particularly limited, but the adsorbing plates 17 may be provided as many as possible so that the sludge contacts as long as possible, or the shape thereof may be zigzag or meandering. It is good.

Then, when a laboratory scale test simulating the first embodiment as shown in FIG. 1 was conducted, the pH of the MAP-particle-free sludge before aeration was 6.3, phosphoric acid While the content of phosphorus phosphorus was 18.6 mg / l, the pH of the sludge after performing aeration for 1 hour increased to 8.4 or more, and the content of phosphorus phosphorus was 16.3 mg. / L, a decrease of 2 mg / l or more compared to before aeration. Similar experiments were performed by simulating the third embodiment. Before the aeration, the pH was 7.5 and the content of phosphoric acid phosphorus was 37.
After the aeration, the pH was 8.8 and the phosphoric acid content was 12.5 mg / l, whereas the phosphoric acid phosphorus content was significantly reduced.

[0019]

In summary, according to the present invention, the following excellent effects can be exhibited.

The MAP is formed by aeration of the sludge before flowing into the pipeline.
Since the particles are forcibly generated and the sludge is caused to flow into the pipeline, the concentration of the MAP particle generation factor component is reduced, and the generation of MAP particles in the pipeline is suppressed.

Further, a filter, a MAP reactor,
By providing the adsorption tank, the sludge can be flown into the pipeline after removing the MAP particles. In this case, it is possible to prevent the MAP particles flowing into the pipeline from adhering to a physically non-existent wall, thereby preventing the sludge from flowing. Safety is further enhanced.

Therefore, it is possible to avoid inconveniences such as a decrease in flow rate and blockage in the pipeline due to the adhesion of MAP particles.

As a result, since the work of cleaning the inside of the pipeline and the work of replacing the pipeline as in the related art are not required, the labor and cost required for this work can be reduced.

Further, since there is no need to clean the inside of the pipeline or replace the pipeline, it is not necessary to stop the facility each time.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing first and second embodiments according to the method of the present invention.

FIG. 2 is a configuration diagram illustrating an example of an aeration apparatus used in the first embodiment.

FIG. 3 is a configuration diagram illustrating an example of a MAP reactor used in a second embodiment.

FIG. 4 is a conceptual diagram showing a third embodiment according to the method of the present invention.

FIG. 5 is a conceptual diagram showing a fourth embodiment according to the method of the present invention.

FIG. 6 is a perspective view showing an example of an adsorption tank used in a fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sewage treatment facility 2 Sludge storage tank 3 Sludge treatment facility 4 Sludge receiving tank 5 Pipe line (sludge pipe) 6 Aeration device 12 MAP reactor 16 Anaerobic digestion tank 17 Adsorption tank

Claims (5)

[Claims] An aeration device is provided upstream of a pipe for transporting sludge, and a sludge is aerated in advance in the aeration device to form MAP particles in the sludge.
A method of preventing pipeline blockage by MAP particles, wherein sludge is sent into the pipeline after removing a generation factor component of P particles. 2. A MAP instead of the aeration device
2. A pipeline blockage by MAP particles according to claim 1, wherein a reactor is provided, and the MAP reactor forms MAP particles in sludge before mud feeding, and the MAP particles are settled and removed. Prevention method. 3. An anaerobic digestion tank is provided upstream of the aeration apparatus or the MAP reactor, and sludge is anaerobically treated in the anaerobic digestion tank in advance. Of preventing pipeline blockage by MAP particles. 4. An adsorption tank in which a plurality of adsorption plates are immersed is provided downstream of the aeration device or the MAP reactor, and sludge is passed through the adsorption tank to adsorb and remove remaining or newly generated MAP particles. The method for preventing pipeline blockage by MAP particles according to any one of claims 1 to 3, wherein: 5. The apparatus according to claim 1, wherein the pipe is a mud pipe connecting the sewage treatment facility and the sludge treatment facility.
5. The method for preventing a pipeline from being clogged by the MAP particles according to any one of claims 1 to 4.