JP2013031793A - Disposal method of sludge waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disposal method of sludge waste, by which disposal space of a large amount of sludge waste produced by natural disaster such as an earthquake, a flood, a tsunami and a typhoon can be easily secured and the sludge waste can be treated at low cost.SOLUTION: The disposal method of sludge waste includes: a classification process for classifying disposal targets being sludge waste into two or more groups having different grain size; and an underground input process for compulsorily inputting at least one group of the disposal target among two or more groups into an underground gap. The underground input process is carried out by an input method handling the grain size of each group.

Description

  The present invention relates to a method for disposing of sludge waste caused by natural disasters such as earthquakes, floods, tsunamis, and typhoons.

  In the Great East Japan Earthquake that occurred on March 11, 2011, it was estimated that approximately 10 to 16 million tons of sludge was generated in the four affected areas (Iwate, Miyagi, Fukushima, and Ibaraki). It is thought that the sediment on the seabed was transported to land by the tsunami.

  In addition, the sludge has various properties such as sand, mud, concrete trash, wood containing wood and the like, and also contains harmful substances, oil such as fuel, and organic matter such as marine products. Such sludge waste is usually classified into earth and sand not containing harmful substances, earth and sand containing harmful substances, earth and sand in which rubble etc. are mixed together, concrete waste, wood waste, metal waste, etc. Detoxification processes such as cleaning, neutralization, and deodorization are performed. Generally, disposal by incineration or landfill in final disposal sites (managed disposal sites, block-type disposal sites, stable disposal sites, etc.) Has been done.

Moreover, patent document 1 and patent document 2 are mentioned as a prior art which reuses sludge waste as a material. Patent Document 1 discloses that sludge generated in a closed water area such as a lake is sun-dried and added with a bactericidal agent, a preservative, etc., and used as a landfill material for constructing an artificial island in the lake. Has been.
Patent Document 2 discloses that a sludge containing heavy metal is subjected to a detoxification process, and the sludge solidified with a solidifying agent is used for landfill.

JP 2001-3337 A JP 2011-88040 A

Here, the sludge generated by this earthquake is a large amount of about 10 million to 16 million tons as described above, which greatly exceeds the processing capacity of the final disposal site and the demand for landfill materials.
Further, it is conceivable to excavate and fill a hole for disposal in the soil other than the final disposal site. In this case, excavated soil is generated when the hole for disposal is excavated, and the large amount of In order to backfill the sludge waste, a large-capacity disposal hole, that is, a disposal space is required, and it is difficult to secure the location.
However, it is urgent to dispose of such a large amount of sludge waste quickly for the reconstruction of the affected areas.

  The present invention has been made in view of the above circumstances, and its purpose is to easily secure a disposal space for a large amount of sludge waste generated by natural disasters such as earthquakes, floods, tsunamis, typhoons, and the like. An object of the present invention is to provide a disposal method of sludge waste that can treat sludge waste at low cost.

  In order to achieve the above object, the sludge waste disposal method according to the first aspect of the present invention includes a classification step of classifying the sludge waste to be disposed into a plurality of groups having different particle sizes, and An underground injection step of forcibly introducing a disposal target of at least one group of the plurality of groups into an underground gap, and the underground injection step includes an injection method corresponding to the particle size of each group Is performed.

The sludge waste disposal method according to this aspect is characterized in that the sludge waste is disposed of in the ground by performing a ground loading step of forcibly throwing it into the gap in the ground. . That is, it is a disposal method that uses the gap between soil particles in the ground as a waste space for sludge waste.
In general soil, the gap in the ground constituted by the gaps between the soil particles ranges from 20% in a tight ground to about 50% in a loose ground, and it can be said that a considerably large waste space exists in the ground.

  A large amount of sludge waste generated by natural disasters such as earthquakes, floods, tsunamis, and typhoons contains wastes of various particle sizes. In the sludge waste disposal method according to this aspect, a classification process is performed for classifying the disposal target, which is sludge waste, into a plurality of groups having different particle sizes. As a result, as will be described later, it is possible to perform an underground charging step of forcibly charging the gaps in the ground by the charging method corresponding to the particle size of each group.

  As a charging method corresponding to the particle size of each group, for example, a known charging method such as a mechanical stirring method, a high-pressure jet stirring method, a pressure injection method, a static compaction method using a casing, or the like can be used. The mechanical agitation method, high-pressure jet agitation method, pressure injection method, static compaction method using a casing, etc., insert a nozzle, injection tube, casing, etc. into the soil to forcibly insert the material into the ground. Therefore, it is only necessary to select an injection method that can be executed using a nozzle or an injection tube having a pipe diameter corresponding to the particle diameter of each group to be disposed of.

  According to this aspect, it is easy to secure a disposal space for a large amount of sludge waste, and it is possible to secure the disposal space in the ground at the disaster site and process the large amount of sludge waste at a low cost.

  The disposal method of sludge waste according to the second aspect of the present invention is the first aspect, wherein the disposal object is at least a group of fine particles mainly composed of sand, mud, and soil, and mainly gravel and concrete glass. The coarse particles are classified into a group of coarse particles, and the fine particles and a group of other particles larger than the coarse particles, and are added to the ground with respect to the fine particles and the coarse particles. A process is performed.

The group of fine particles mainly consisting of sand, mud, and soil is a group containing fine particles of about 2 mm or less, for example, shells, wood, asphalt, etc. May be included. In addition, the group of coarse particles mainly composed of gravel and concrete glass is, for example, a group including medium particles of more than 2 mm and about 40 mm or less. As particles other than gravel and concrete glass, It may contain wood pieces, asphalt pieces, cohesive soil masses, and the like.
The fine grain part and other grain part groups larger than the coarse part are wood pieces, concrete blocks, metal pieces, plastic pieces, etc. larger than the coarse part.

  According to this aspect, the effect of the first aspect can be obtained for the sludge waste of the fine-grained group and the sludge waste of the coarse-grained group.

  The disposal method of sludge waste according to the third aspect of the present invention is the second aspect, after pulverizing the fine particles obtained by the classification step and other particles larger than the coarse particles. The pulverized product is subjected to a classification step.

  According to this aspect, the fine particles and other particles larger than the coarse particles are pulverized, the classification process is performed on the pulverized product, and the sludge waste originally contained as the large particles is used. In contrast, it is possible to perform an underground charging process and throw it into the underground gap for disposal.

  The sludge waste disposal method according to the fourth aspect of the present invention includes a dilution step in which water is added to the sludge waste to form diluted mud water in any one of the first to third aspects. Then, the classification step is performed.

According to this aspect, sludge waste usually has a high viscosity, but it is classified by a classifier such as a vibrating sieve type or a centrifugal classification type by diluting with water to give a predetermined fluidity. The process can be performed efficiently.
In addition, the water used for dilution can also use river water and seawater other than industrial water and tap water.

It is a schematic diagram explaining a series of flows of the processing method of sludge waste concerning the present invention. It is an example of the injection | throwing-in method which performs an underground injection | pouring process, and is a figure explaining the injection | throwing-in method by a mechanical stirring system. It is an example of the injection | throwing-in method which performs an underground injection | throwing-in process, and is a figure explaining the injection | throwing-in method by a high pressure jet stirring system. It is an example of the injection | throwing-in method which performs an underground injection | pouring process, and is a figure explaining the injection | throwing-in method by a pressure injection system. It is an example of the injection | throwing-in method which performs an underground injection | pouring process, and is a figure explaining the injection | throwing-in method by the static compaction system by a casing. It is a figure explaining the trial calculation conditions of the disposal amount of sludge waste.

[Example 1]
Hereinafter, embodiments of a method for treating sludge waste according to the present invention will be described with reference to the drawings. In addition, this invention is not limited to the following embodiment.
FIG. 1 is a schematic diagram illustrating a series of flows of a sludge waste processing method according to the present invention.

First, the sludge waste 1 is introduced into a dilution tank 2 and is made into diluted mud water having a predetermined fluidity by adding water 3 (dilution step). Water used for diluting the sludge waste 1 can be river water or seawater in addition to industrial water and tap water.
When the sludge waste 1 has a bad odor or the like, it is desirable to take a bad odor removal measure by chemical treatment or microbial treatment in this dilution step. It is desirable to take pest countermeasures by chemical treatment as necessary.

After performing the dilution step, the diluted mud water 4 is sent to the classifier 5. The classification device 5 classifies the sludge waste 1 to be disposed of into a plurality of groups having different particle sizes.
As the classifier 5, a known classifier 5 such as a vibration sieve type, a centrifugal classifier, or a cyclone type can be used. In this embodiment, the wet classifier 5 is used, but when the dilution step is not performed, a dry classifier may be used.

  By the classification process by the classification device 5, the sludge waste 1 to be disposed of is divided into a plurality of groups having different particle sizes, that is, group 1, group 2, group 3, group 4,. Classified.

Here, in this example, group 1 is a group of fine particles mainly composed of at least sand, mud, and soil, and includes fine particles of about 2 mm or less, for example, particles other than sand, mud, and soil. For example, a shell piece, a piece of wood, an asphalt piece, etc. are included.
Group 2 is a group of coarse particles mainly composed of gravel and concrete glass, and includes medium particles of more than 2 mm and less than or equal to 40 mm. As particles other than gravel and concrete glass, for example, shells Includes pieces, wood pieces, asphalt pieces, cohesive soil masses, etc.
Group 3 to Group n are groups of fine grains and other grains larger than the coarse grains, and include wood pieces, concrete blocks, metal pieces, plastic pieces, etc. larger than the coarse grains. .

The disposal target of at least one of the plurality of groups is sent to an underground injection process for forcibly introducing into the underground gap. In this embodiment, the sludge waste of group 1 and the sludge waste of group 2 are sent to the underground charging process. Depending on the size of each sludge waste, other group sludge waste can be used for backfilling or embankment, or sent to an intermediate treatment facility for processing sludge waste into construction materials. Or sent to a final disposal site (managed disposal site, intercepted disposal site, stable disposal site, etc.).
In addition, after classification, it is desirable to carry out purification treatment or insolubilization treatment of harmful substances as necessary.

Next, the underground charging process performed for the sludge waste divided into group 1 and group 2 will be described. The underground charging process is performed by a charging method corresponding to the particle size of each group.
As a charging method corresponding to the particle size of each group, for example, a known charging method such as a mechanical stirring method, a high-pressure jet stirring method, a pressure injection method, a static compaction method using a casing, or the like can be used. The charging method is not limited to these methods as long as the classified sludge waste can be forcibly charged into the underground gap.

  Hereinafter, as examples of the charging method, four methods of a mechanical stirring method, a high-pressure jet stirring method, a pressure injection method, and a static compaction method using a casing will be described. FIG. 2 is a diagram for explaining a charging method using a mechanical stirring method. FIG. 3 is a diagram for explaining a charging method using a high-pressure jet stirring method. FIG. 4 is a diagram for explaining a charging method using a pressure injection method. FIG. 5 is a diagram for explaining a charging method by a static compaction method using a casing.

<Mechanical stirring method>
As shown in FIG. 2, a stirring device 10 having a stirring blade 12 having a jet nozzle 11 for injecting slurry-like sludge waste is inserted into the soil, and the slurry from the jet nozzle 11 is rotated while the stirring blade 12 is rotated. By injecting the sludge waste, the sludge waste can be forced into the gap in the ground. It is desirable that the sludge waste used in this method has a size that is 1/4 to 1/2 or less of the diameter of the ejection nozzle 11. For example, when the diameter of the ejection nozzle 11 is φ3.5 mm, the particle size of the sludge waste is preferably about 2 mm or less.

<High-pressure jet stirring method>
As shown in FIG. 3, the sludge waste slurry and the compressed air are simultaneously rotated and jetted from the jet nozzle 21 provided on the rod 20 of the single pipe or the multi-pipe, and the columnar shape is injected into the ground. Forms sludge waste mass. Specifically, in the ground with a gap between soil particles, the space between the soil particles is crushed to create a space, and the cylindrical sludge waste lump is formed. Therefore, the forced introduction of sludge waste into the underground gap is achieved.
It is desirable that the sludge waste used in this method has a size that is ¼ to ½ or less of the jet nozzle diameter. For example, when the ejection nozzle diameter is 3.5 mm, it is desirable that the particle size of the sludge waste is about 2 mm or less.

<Pressure injection method>
As shown in FIG. 4, the sludge waste lump is formed by inserting an injection pipe 30 for injecting sludge waste into the soil and pressure-injecting sludge waste with a viscosity of a raw concrete-like viscosity. Also in this method, the sludge waste lump is formed by pressing the gap between the soil particles by pressure injection of the sludge waste to form a space. Plural sludge waste lumps are formed while pulling up the injection pipe little by little.
The tube diameter of the injection tube is generally about φ50 to 100 mm. The particle size of the sludge waste is preferably ¼ to ３ of the pipe diameter of the injection pipe. For example, when using an injection tube with a diameter of 50 mm, it is desirable that the particle size of the sludge waste is about 15 mm or less.

<Static compaction method using casing>
As shown in FIG. 5, by using the casing 40 provided with the excavation head 41 at the tip, moving the casing 40 up and down while rotating the excavation head, and further introducing sludge waste into the ground through the casing 40, While excavating the ground, the sludge waste is compacted and expanded. That is, the compaction compacts the gap between the soil particles to create a space, and the sludge waste is forcibly introduced into the soil.
The diameter of the casing 40 is generally about φ400 mm to 1000 mm. About the particle size of sludge waste, about 40 mm or less which is easy to compact is desirable.

  The mechanical agitation method, high-pressure jet agitation method, pressure injection method, static compaction method using a casing, etc. all insert sludge waste into the soil by inserting a nozzle, injection tube, casing, etc. An injection method that can be performed using a nozzle or an injection tube having a pipe diameter corresponding to the particle diameter of each group to be disposed of can be selected.

  In the present embodiment, for the sludge waste of group 1 fine particles (2 mm or less), the underground charging step is performed using a mechanical stirring method or a high-pressure jet stirring method. For the sludge waste of Group 2 coarse particles (over 2 mm but not more than 40 mm), the above-mentioned underground charging process is performed by a pressure injection method or a static compaction method using a casing.

  In this embodiment, the dilution process is performed and classification is performed using a wet classifier. Therefore, the slurried sludge waste after the classification can be sent as it is to the underground charging process by the mechanical stirring method or the high-pressure jet stirring method. The sludge waste having a particle size used in the underground charging process by the pressure injection method or the static compaction method by the casing is appropriately dehydrated.

In addition, when sludge waste is forced into the ground gap and slurry water or water originally contained in the ground springs up to the surface, Work while aspirating.
Also, as a result of the forced input of sludge waste into the ground, the vicinity of the ground surface may rise, but it should be leveled with a roller car, grader, etc.

The disposal method of sludge waste according to the present invention is characterized in that the sludge waste is disposed of in the ground by performing a ground loading step of forcibly throwing it into the gap in the ground. . That is, it is a disposal method that uses the gap between soil particles in the ground as a waste space for sludge waste.
A large amount of sludge waste generated by natural disasters such as earthquakes, floods, tsunamis, and typhoons contains wastes of various particle sizes. In the sludge waste disposal method according to the present embodiment, a classification process is performed in which the disposal target, which is sludge waste, is classified into a plurality of groups having different particle sizes. This makes it possible to forcibly throw into the gaps in the ground by the feeding method (mechanical stirring method, high-pressure jet stirring method, pressure injection method, static compaction method using a casing, etc.) corresponding to the particle size of each group. It is possible to carry out a medium charging process.

According to the present embodiment, it is easy to secure a disposal space for a large amount of sludge waste, and it is possible to secure the disposal space in the ground at the disaster site and process the large amount of sludge waste at a low cost. .
Examples of treatment sites for sludge waste include seawalls, seawalls of breakwaters, revetments, backside grounds of quay walls, roads, lower grounds of parks, and the like. In addition, if the sludge waste thrown into the ground contains hazardous substances exceeding the standard value, it is possible to prevent the spread of environmental pollution to the surrounding area by installing a water shielding work around the treatment plant as necessary. it can.

[Example 2]
Next, another embodiment of the sludge waste disposal method according to the present invention will be described.
In this example, among the groups obtained by the classification process of Example 1, the group containing other grains larger than the groups (Group 1 and Group 2) that were injected into the ground by performing the underground charging process. After the sludge waste is pulverized and made fine, the classification process is performed again on the pulverized product.
As a result, since it is possible to perform the underground charging process even for the sludge waste originally contained as a large grain fraction, the amount of sludge waste that can be provided to the underground charging process increases, and more Sludge waste can be treated by this method.

[Estimated disposal of sludge waste]
The disposal amount of sludge waste was estimated when the site shape was 100 m wide × 100 m long and the target sludge waste input layer was 20 m underground (see FIG. 6). Table 1 shows the result of trial calculation when there is one construction machine. Table 2 shows the processing capacity of the processing method used for “backfill and embankment”, the processing method reused for construction materials such as cement and brick at the “intermediate processing facility”, and the processing method for landfilling in the managed final disposal site. And processing costs.

1 sludge waste, 2 dilution tank, 3 water,
4 dilution mud, 5 classifier,
10 stirring device, 11 ejection nozzle, 12 stirring blade,
20 rods, 21 ejection nozzles,
30 injection tube,
40 casing, 41 excavation head

Claims (4)

A classification process for classifying the sludge waste to be disposed of into a plurality of groups having different particle sizes;
A ground injection step of forcing the disposal target of at least one group of the plurality of groups into a gap in the ground, and
The disposal method for sludge waste, wherein the underground charging step is performed by a charging method corresponding to a particle size of each group. In the disposal method of the sludge waste described in Claim 1,
The disposal object is at least
A group of fine grain mainly consisting of sand, mud and earth,
A group of coarse grains mainly consisting of gravel and concrete rubble;
A group of fine grains and other grains larger than the coarse grains;
Classified into
A method for disposing of sludge waste, characterized in that the underground charging step is performed on the fine particles and the coarse particles. In the disposal method of sludge waste described in claim 2,
A method for disposing of sludge waste, characterized by performing a classification step on the pulverized product after pulverizing the fine particles obtained by the classification step and other particles larger than the coarse particles. .   In the disposal method of sludge waste as described in any one of Claims 1-3, after performing the dilution process which adds water to the said sludge waste, and makes it a diluted muddy water, it performs the said classification process. And disposal method of sludge waste.

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