JP2002018500A - Water reducing method for high-water-content industrial waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily reduce the water content of a high-water-content industrial waste, of which the treatment has been difficult, to thereby provide its handling method and convert the waste into a useful material. SOLUTION: In order to reduce the water content of a high-water-content industrial waste, a water-permeable bag is filled with a simple-type water absorbent, such as rock wool, quicklime, or calcined gypsum, or a reactive-type water absorbent. The bag containing the water absorbent is immersed in the high-water-content industrial waste to cause the absorbent to indirectly absorb water alone, thus enabling water in the waste to be reduced without changing the pH or physical properties of the waste. The absorbent having absorbed water in the bag can be recycled by drying, thermal decomposition and dewatering, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reducing the volume of a high-water content industrial waste by removing water from the high-water content industrial waste containing a large amount of water and reducing the water content. In particular, the present invention relates to a water-reducing industrial waste water reducing method capable of rapidly reducing only the water content without changing the physical properties such as PH of the high water-containing industrial waste. Further, the present invention relates to a method for reducing high water content industrial waste, wherein the water absorbing material used in the water reducing method can be recycled.

[0002]

2. Description of the Related Art In recent years, with the development of civil engineering and construction, new high water-containing industrial wastes have been generated frequently, and environmental pollution has become a serious problem. Hundreds of millions of tons of crushed stone water from the crushed stone industry per year, 200 million tons of limestone from the production of limestone per year, sludge from rivers and lakes, marine dredging, and sludge from manure from various livestock. Increasingly, environmental pollution is becoming a serious problem. What is common to these is industrial waste that generates a large amount of water and has a high water content. In addition, since each of them is in a slurry state, its treatment is extremely difficult, which is a serious problem.

Heretofore, in order to treat these highly hydrated industrial wastes, natural or mechanical dehydration has been required over a vast area and for a long time. In addition, lime-based and cement-based solidification materials are directly mixed into this highly water-containing industrial waste, and then one part is used and then disposed of in landfill or incinerated. I was On the other hand, since the amount of this highly water-containing industrial waste is increasing year by year, such disposal such as dumping and incineration is not completely performed, and at present, there is an increase in what is left untreated.

[0004]

These highly water-containing industrial wastes are always continuously generated in large quantities, sometimes contain harmful components, and livestock manure emits offensive odor. Therefore, the problem of environmental pollution is serious, and these are all industrial waste sludges that violate the “Industrial Waste Treatment and Cleaning Law”. In order to dispose of these industrial wastes, it was necessary to secure special treatment sites or transport them to distant places, all of which required a great deal of expense.

On the other hand, some of these highly hydrous industrial wastes contain an active ingredient. Therefore, this includes resources that can be recycled and recycled. On the other hand, a technique for reducing and solidifying the water by a simple method is desired.

Recently, in order to improve many of the above-mentioned problems, for example, Japanese Patent Application Laid-Open No. 9-192635 (first known invention) or Japanese Patent Application Laid-Open No. 2000-5800 (second
Known invention) has already been invented and disclosed.

[0007] The first known invention described above absorbs water, such as coffee, juice, and liquor, remaining from empty cans and empty bottles discarded in containers such as waste collection containers without directly touching the container. It is an invention that can prevent the generation of off-flavors and odors and maintain hygiene. In particular,
The dried okara and the slaked lime powder are put in a cloth bag to form a moisture absorbing bag, and the moisture absorbing bag is inserted into a container such as a waste collection container while being suspended via a string or the like, and the container is inserted into the container. This is a technology in which water that may generate an off-flavor, an off-flavor, or the like that has flowed to the bottom of the inside is absorbed and removed by a moisture absorbing bag.

[0008] However, the first known invention described above can absorb and remove a small amount of water remaining at the bottom of a container such as a waste collection container, but muddy water, sludge, livestock, etc. However, there is a problem that it is difficult to efficiently absorb and treat a large amount of water of the highly water-containing industrial waste itself having a water content of about 50% or more such as manure sludge. Further, in the case of the first known invention, since dried okara and the like are put into a cloth bag to constitute a moisture absorbing bag and used, it is difficult to reuse moisture-absorbed okara and the like. There was a problem that such okara was newly turned into industrial waste.

The above-mentioned second known invention is configured so that a plurality of unit bags are connected and provided by a band-shaped nonwoven fabric having water permeability so that the unit bags can be wound in order, and that moisture is removed from an opening of the unit bag. This is a technique in which sludge or the like containing slag is stored in each bag and compressed to dewater the water in the sludge.

[0010] However, in the above-mentioned second known invention, the entire high-water-containing industrial waste containing a large amount of water such as sludge must be divided into a plurality of unit bags, stored and processed for each bag. Therefore, there is a problem that the operation efficiency is extremely poor and the processing cost is extremely high.

Furthermore, in addition to the above-mentioned two types of known inventions, various water-absorbing materials are directly mixed into high-water-content industrial waste containing a large amount of water, such as sludge, to reduce the amount of high-water-content industrial waste. A method of reducing the water content of highly hydrated industrial waste by absorbing water therein with a water absorbing material has also been developed and has been put to practical use in some cases.

However, in this case, since the water-absorbing material is directly mixed into the highly hydrated industrial waste, the amount of the industrial waste is increased and the bulk is increased. Since the pH and other properties of the high-water-containing industrial waste are changed by burdensome problems and water-absorbing materials mixed into the high-water-containing industrial waste, the high-water-containing industrial waste is treated with bacteria or the like. There is a problem that adverse effects occur when used effectively.

In addition to the above-mentioned two known inventions, some of the inventors of the present invention have invented, for example, a highly water-containing industrial waste as disclosed in Japanese Patent Application Laid-Open No. 8-229531. The technique of the solidification method is also known (third known invention).

According to the third known invention, a highly water-containing industrial waste is rapidly cured by relatively simple and easy means, whereby an industrial waste having a high water content is converted into a cured product,
This technology aims to facilitate subsequent handling of industrial waste. Then, in order to achieve the above-mentioned object, one or more kinds selected from calcined gypsum or anhydrous gypsum are mixed into high water content industrial waste such as sediment of water and sewage treatment, sludge, and processed animal waste. This is a technique of a method for solidifying high-water-content industrial waste by adding and solidifying high-water-content industrial waste to facilitate transportation and the like.

According to the third known invention, it is possible to solidify high-water-content industrial waste to facilitate subsequent treatment. However, in this solidification method, only the water content of high-water-content industrial waste is reduced. There is a problem that it becomes difficult to treat the highly water-containing industrial waste after the water is reduced with bacteria and the like to effectively use the waste. Further, when calcined gypsum or the like is directly mixed into the highly hydrated industrial waste as in the third known invention, the pH and other properties of the highly hydrated industrial waste are changed, and this highly hydrated industrial waste is changed. There were also problems that hindered the effective use of industrial waste.

The present invention is a completely new technology developed in view of the above-mentioned many problems in the prior art. In particular, a water-permeable bag previously filled with a water-absorbing material is directly immersed in high-water-containing industrial waste. It is an object of the present invention to provide a completely new technology in which the water in the surrounding high-water-containing industrial waste is absorbed by the water-absorbing material in the water-permeable bag to reduce the water in the high-water-containing industrial waste.

[0017]

Means for Solving the Problems The present inventors systematically conducted research on a method for rapidly reducing the water content of a highly water-containing industrial waste. As a result, we focused on using various types of highly hydrous industrial wastes using simple water-absorbing materials such as rock wool or reactive water-absorbing materials such as quicklime, calcined gypsum, and lightly burnt dolomite. These various water-absorbing materials are filled in advance in a water-permeable bag made of cotton, silk, synthetic fiber, or paper. Next, the water-absorbent material of the water-permeable bag absorbs the water in the highly hydrated industrial waste, and then the dried or heated water-absorbent material is recycled, whereby this problem can be solved economically in a short time. Was invented.

According to the present invention, as a means for solving the above-mentioned problems, a water-absorbing material is indirectly inserted through a water-permeable bag without directly putting the water-absorbing material into the high-water-containing industrial waste. The present invention is an invention in which the water of a highly hydrated industrial waste is efficiently reduced by contact with the water of the waste.

The highly water-containing industrial waste to be treated in the present invention is not particularly limited, and generally has a problem in disposal. Specifically, plants generated in ready-mixed concrete factories, washing residues of mixer trucks, sedimentation from water and sewage treatment, sludge, livestock manure, soft mud, limestone or crushed stone flushing mud, underground excavated mud, etc. Become. These are all slurry-like high water content mud, and are all high water content industrial wastes which are the object of the present invention.

The remaining ready-mixed concrete generated from a ready-mixed concrete factory will be described as an example of a high water content industrial waste. In a ready-mixed concrete factory, washing of a mixer and washing of a concrete mixer truck for transportation are constantly repeated. In a ready-mixed concrete plant, these slurries of water washing are stored in a pool, and the slurries are collected by a primary sieve and sand is collected by a secondary sieve. Since a large amount of residual water contains cement, each factory separates the water and cement cake by a filter press. The water is reused as concrete mixing water again.

However, since there is no effective utilization technology of the filter cake after being used as described above, the filter cake is currently disposed of. Therefore, the filter cake generated in large quantities has become an industrial waste. In particular, a ready-mixed concrete factory located in a large city has a problem that it is difficult to secure a pool that can temporarily store the slurry because the site area is small. Therefore, the development of the technology of the method for reducing the water content of industrial waste containing high water content as in the present invention has been expected.

The gist of the structure of the method for reducing the water content of a highly hydrated industrial waste according to the present invention is as follows. A water permeable bag is filled with a water absorbing material, and the water permeable bag filled with the water absorbing material is contained in the high water content industrial waste. By immersion, only the water in the highly hydrated industrial waste is indirectly absorbed to reduce the amount of the highly hydrated industrial waste, and the permeable bag immersed in the highly hydrated industrial waste is raised. This is a method in which water-containing industrial waste is taken out of the waste, and the water-absorbing material therein can be reused by drying or heating.

Further, the above-mentioned water-absorbing materials used according to the present invention can be broadly classified into two types, a reaction-type water-absorbing material and a simple-type water-absorbing material. As the former reactive water-absorbing material, quicklime, lightly burned dolomite, plaster of Paris, and the like can be effectively used. The characteristic of this reactive type water-absorbing material is that it absorbs water while hydrating in response to the water content of highly hydrated industrial waste, so it absorbs muddy water, feces and urine water, etc. mixed in the highly hydrated industrial waste as it is. Instead, it is possible to reduce the water content in the high water content industrial waste while absorbing only pure water (H ₂ O). Therefore,
It is possible to prevent the loss of the active ingredient in the case where the high water-containing industrial waste is to be effectively used after the water is reduced.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method for reducing the water content of highly hydrated industrial waste according to the present invention has already been described in detail for the essential parts of its structure. It is as follows.

That is, in the form of the first example, a water absorbent made of quicklime is filled in a water-permeable bag made of cotton cloth in advance,
The water-permeable bag thus configured was inserted and temporarily immersed in highly hydrous industrial waste made of manure sludge of livestock.
Then, the quicklime was hardened by absorbing the water permeating the water-permeable bag into the quicklime in the water-permeable bag, thereby hardening the quicklime. As described above, by absorbing the water into the quicklime in the water-permeable bag, the water contained in the highly hydrated industrial waste could be reduced by 30%.

As described above, after the quick-lime, which is the water-absorbing material, has sufficiently absorbed water, the water-permeable bag is taken out of the highly water-containing industrial waste, and the water-permeable bag is hydrated and hardened. By heating the quicklime, the water that had absorbed water was evaporated and dried, and the quicklime could be reused.

On the other hand, high water-containing industrial waste consisting of livestock excreta sludge reduced by about 30% absorbs only H ₂ O by reaction of quicklime with water. Only increases the pH of the highly hydrated industrial waste
And physical properties do not change. The highly water-containing industrial waste thus treated could be effectively used as an agricultural fertilizer by mixing and processing bacteria and the like therein.

Next, in a second embodiment, a method for reducing a large amount of highly hydrated industrial waste discharged from a ready-mixed concrete factory will be described. In this case, first, gravel and sand in the high water content industrial waste are separated, and then the cement slurry is stored in the pool. On the other hand, a water-absorbent bag previously filled with a water-absorbing material made of rock wool in a bag made of cotton cloth is pressed into the pool of the cement slurry and immersed, and the water permeating into the water-permeable bag is removed. Water was absorbed by rock wool in a short time, and when the water content of the cement slurry in the pool was reduced by about 15%, the water-permeable bag was taken out of the pool.

Further, this time, a water-permeable bag, in which calcined gypsum as a water-absorbing material is filled in a bag made of cotton cloth in advance, is mixed with cement slurry in the pool whose water content has been reduced to about 15% as described above. The cement slurry was immersed in the cement slurry and water was absorbed with calcined gypsum to further reduce the water content of the cement slurry to about%. As described above, by reducing the water content of the cement slurry twice, the bulk of the cement slurry could be significantly reduced, and the subsequent handling of the cement slurry could be facilitated. In addition, rock wool or calcined gypsum used for reducing the water content of the cement slurry could be reused by performing water removal by a press, drying, or heat treatment, respectively.

The basic mode of the water reducing method of the present invention is as described above, and specific examples of the water reducing method of the present invention will be described as follows.

[0031]

EXAMPLE 1 A specific example of reducing the water content of manure sludge having a water content of 80 to 100% with quicklime will be described. That is, sludge 1
A permeable bag in which quicklime is enclosed in a ratio of 1 to 2 is mixed with manure sludge having a water content of 80 to 100%.
After immersion for minutes, the bag of quicklime was taken out, and the moisture content of the manure sludge was 40 to 50%. And by the decrease of water at this time, the abnormal odor peculiar to manure sludge could be remarkably reduced.

[0032]

Example 2 Limestone washed sludge was prepared according to JISA1
203 was performed. This result indicates that the water content is 2
4.5%, liquid limit 24.4%, plastic limit 21.5
%. The density was 2.7 (g / cm ³ ). Also, this sludge is 95% silty and 5%
Percent was sand. Further, the pH is between 7.5 and 8.0,
Very difficult to handle.

A washing sludge having such a structure is used for one washing sludge.
1 beaker, water was added and the mixture was stirred well. The water content at this time was 500%. By pushing a cotton permeable bag containing 50 g of rock wool into this beaker,
Rock wool in the permeable bag absorbed water. Ten minutes later, when the water-permeable bag was pulled up and measured, the water content of the mud in the beaker was 2
00%. Further, a cotton permeable bag filled with 50 g of rock wool was pushed into a beaker. Ten minutes later, the water-permeable bag was pulled up, and the water content was measured. As a result, it was found that 3 to 5 g of water was absorbed per 1 g of rock wool. In addition, rock wool used for the second time,
The dried rock wool used for the first water absorption was reused.

[0034]

EXAMPLE 3 Mud water having a water content of 120% was prepared by using limestone washed sludge as a raw material and adding water thereto. A cotton water-permeable bag containing 50 g of rock wool was placed in 500 cc of muddy water having a water content of 120%. The rock wool in this permeable bag immediately absorbed water. After 15 minutes, the water content of the muddy water dropped to 67%. Next, 100kg in this muddy water
A cotton permeable bag containing quick lime equivalent to / m ³ was placed. The water content of the muddy water was further reduced, the water content was reduced to 20%, and the fluidity was completely lost. The rock wool and quick lime used in this example could be reused by drying, heating and the like.

[0035]

Example 4 Limestone sludge was used as a raw material, and water was added thereto to form a slurry having a water content of 70%. This water content ratio 7
200 kg / m ³ for 500 cc of 0% slurry
A water-permeable bag made of cotton containing calcined gypsum corresponding to (1) was put in to absorb water. After 1 hour, the water content of the slurry had dropped to 40%. Next, a cotton water-permeable bag having quicklime equivalent to 100 kg / m ³ was put into the slurry and immersed. After 30 minutes, the water content dropped to 20.5% with heat generation. This state could be reached below the water content ratio of the plastic limit value of this raw material. The calcined gypsum and the quicklime used in this example could be reused by heating.

[0036]

As is apparent from the above description of the construction and operation of the method for reducing the water content of a highly water-containing industrial waste according to the present invention, a water-permeable bag filled with a water-absorbing material contains a large amount of water. Since it is a method of immersion in industrial waste, it can permeate into the water-permeable bag and absorb only water by the water-absorbing material, thereby easily and reliably reducing the water in the highly water-containing industrial waste. .

Since the water-absorbing material that has absorbed water is taken out of the high-water-containing industrial waste together with the water-permeable bag, there is no concern that the volume of the high-water-containing industrial waste will increase, and the water-absorbing material will be contained in the high-water-containing industrial waste. PH of mixed high water content industrial waste
And does not change its physical properties. Further, the water-absorbing material taken out of the highly water-containing industrial waste can be easily reused by performing a treatment such as drying and heating.

When the water-absorbing material filled in the above-described water-permeable bag is a reactive water-absorbing material such as quicklime, lightly-burned dolomite, and plaster of Paris, the water-absorbing material absorbs water while reacting with water. Since only pure water out of the water in the industrial waste is absorbed and reduced, there is no need to worry about the water-absorbing material unnecessarily absorbing and removing the active ingredients mixed in the highly aqueous industrial waste. The concentration of the active ingredient in the hydrated industrial waste can be effectively increased.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akira Hanada 2-57-7 Kajiwara, Kamakura-shi, Kanagawa Prefecture (72) Inventor Riichi Harada 4-18-18 Magome, Ota-ku, Tokyo F-term (reference) 4D004 AA02 AA03 AA32 AB01 BA04 CA13 CA22 CC11 4D059 AA01 AA03 AA07 AA09 AA30 BE04 BE13 BE53 DA04 DA06 DA51 DA54 DA65 4G066 AA11B AA17B AA47B AA63B AA66B AA68B AA71B BA12 CA43 DA15 GA01

Claims (5)

[Claims] In a method for removing and reducing the water content of a high water content industrial waste containing a large amount of water, a water permeable bag previously filled with a water absorbing material is immersed in the high water content industrial waste. Absorbing water in the highly hydrated industrial waste into the permeable bag to reduce the amount of the highly hydrated industrial waste, and then removing the permeable bag from the highly hydrated industrial waste for treatment. How to reduce water-containing industrial waste. 2. A water-absorbing material filled in the water-permeable bag is at least one water-absorbing material selected from reactive water-absorbing materials such as quicklime, lightly-burned dolomite and calcined gypsum. The method for reducing water content of a highly hydrated industrial waste according to claim 1. 3. The water-absorbing material filled in the water-permeable bag is one or more water-absorbing materials selected from simple type water-absorbing materials such as rock wool, glass wool, fibers, and porous clays. The method for reducing water content of highly hydrated industrial waste according to claim 1. 4. The high water-containing industrial waste includes various construction residual soil, muddy water, washing muddy water of limestone or crushed stones, sludge generated by washing rivers, lakes and marshes, seabeds, and leftovers discharged from the food and beverage industry or households. 2. The method for reducing water content of highly water-containing industrial waste according to claim 1, wherein the sludge is livestock manure sludge. 5. The treatment of the water-permeable bag taken out of the highly water-containing industrial waste is carried out such that the water-absorbing material in the water-permeable bag is dried or heated and dried to remove water and reuse it. 2. The method for reducing the water content of a highly hydrated industrial waste according to claim 1, wherein: