JPH05202350A - Water content-regulating material - Google Patents

Abstract

PURPOSE:To provide the subject material capable of regulating water content of organic matter-contg. sludge, of shortening its fermentation treatment time, and of suppressing odor generation therefrom, through utilizing waste cellular lightweight concrete materials, comprising cellular lightweight concrete granules and coal ash. CONSTITUTION:The objective regulating material comprising (A) cellular lightweight concrete granules (pref. <=4mm in diameter) and coal ash (pref. pulverized coal boiler ash, stoker boiler ash, or fluidized bed boiler ash) at the volume ratio of pref. (1:9) to (9:1).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water conditioner, and in particular, when sludge containing an organic substance is fermented to be composted and reused, it is added for the purpose of adjusting the water content and improving the air permeability. The present invention relates to a water content adjusting material effective as a fermentation aid.

[0002]

2. Description of the Related Art Conventionally, as a fermentation aid for organic matter-containing sludge, which is added for the purpose of adjusting water content, improving air permeability, etc., when sludge containing organic matter is fermented to be composted and reused. , Mainly sawdust was used. However, although the sawdust is effective in improving the air permeability, it has a problem that it has a poor moisture adjusting ability. Further, since the sawdust itself also ferments and emits a bad odor, there is a problem that the working environment and the surrounding environment are deteriorated.

On the other hand, the effectiveness of the inorganic porous material has been confirmed as having the ability to improve air permeability and the ability to adjust water content, which are essential conditions as a fermentation aid, and to have the ability to adsorb organic substances and the like. There is.

[0004]

As described above, although the inorganic porous material is effective as a fermentation aid for organic matter-containing sludge, it is actually expensive because it is very expensive if it is produced from raw materials. Is not manufactured.

On the other hand, as an inexpensive material, a foamed lightweight concrete waste material that is industrial waste is crushed into a suitable size and is commercially available. However, since foamed lightweight concrete is autoclaved or steam-cured in its manufacturing process, it has a high water content of 20% or more and is inferior in water content adjusting ability.

The present invention can utilize the characteristics of the foamed lightweight concrete waste material that is inexpensive, has an excellent ability to improve air permeability, and has an ability to adsorb malodorous components, and further contains an organic substance having an excellent ability to control the water content. It is an object to provide a water content adjusting material as a fermentation aid for sludge.

[0007]

According to a first aspect of the present invention, there is provided a water content adjusting material for adjusting the water content of organic matter-containing sludge, which comprises a mixture of foamed lightweight concrete particles and coal ash. Characterize.

A moisture conditioner according to a second aspect of the present invention is the moisture conditioner according to the first aspect, characterized in that the grain size of the foamed lightweight concrete particles is 4 mm or less.

The moisture conditioner of claim 3 is the same as that of claim 1 or 2.
In the moisture control material of, coal ash is pulverized coal boiler ash,
It is characterized by being at least one selected from the group consisting of stalker boiler ash and fluidized bed boiler ash.

The moisture conditioner of claim 4 is the moisture conditioner of claims 1 to 3, wherein the mixing ratio of the foamed lightweight concrete particles and the coal ash is 1: 9 to 9: 1 by volume. It is characterized by

The moisture conditioner of claim 5 is the moisture conditioner of claim 5, wherein the moisture conditioner for adjusting the amount of water in the organic matter-containing sludge is formed by granulating a mixture of foamed lightweight concrete powder and coal ash. It is characterized by being done.

According to a sixth aspect of the present invention, there is provided the moisture conditioner of the fifth aspect, wherein the particle size is 1 to 4 mm.

The moisture conditioner according to claim 7 is the moisture control material according to claim 5 or 6.
In the moisture control material of, coal ash is pulverized coal boiler ash,
It is characterized by being at least one selected from the group consisting of stalker boiler ash and fluidized bed boiler ash.

The moisture conditioner according to claim 8 is the moisture conditioner according to any one of claims 5 to 7, wherein the mixing ratio of the foamed lightweight concrete powder and the coal ash is 1: 9 to 9: 1 by volume. Characterize.

The present invention will be described in detail below.

In the present invention, it is preferable to use the foamed lightweight concrete waste material as the foamed lightweight concrete from the viewpoints of cost reduction of products and effective utilization of industrial waste.

As the coal ash, there are pulverized coal boiler ash, stalker boiler ash, fluidized bed boiler ash and the like. Any of these may similarly be used, and any of them may be used. .. However, pulverized coal boiler ash, stalker boiler ash, and fluidized bed boiler ash are burned at high temperatures in this order, and as the combustion temperature rises, the surface vitrifies and water retention capacity becomes poor. Further, as it becomes a low temperature combustion type, there is a tendency that the number of fine pores increases and the bad odor adsorption capacity is excellent, so that fluidized bed boiler ash, stalker boiler ash, and pulverized coal boiler ash are preferable in this order.

The following is an example of the case where the moisture control material of the present invention, which is a combination of a foamed lightweight concrete waste material and a fluidized bed boiler ash, is used as a moisture control material as a fermentation aid for organic matter-containing sludge. Will be described in more detail.

As a method of using a mixture of foamed lightweight concrete waste material according to the present invention and fluidized bed boiler ash as a water content adjusting agent, a method of mixing a mixture of foamed lightweight concrete waste material and fluidized bed boiler ash in advance with sludge There are two types: a method of adding foamed lightweight concrete waste material and a fluidized bed boiler ash to sludge and mixing them separately. In any method, by mixing foamed lightweight concrete waste material with fluidized-bed boiler ash, quick lime contained in the fluidized-bed boiler ash reacts with water and is accompanied by a reaction to change to slaked lime. Promotes a decrease in water content. In particular, since this reaction is accompanied by heat generation, the latter method also has an effect of heating sludge, which promotes fermentation. Therefore, the latter method is advantageous in terms of the fermentation promoting effect. is there. However,
Since any of the methods can obtain a sufficient moisture adjusting effect, any method may be used for use as the moisture adjusting material.

The mixing ratio of the foamed lightweight concrete waste material and the fluidized bed boiler ash is determined in consideration of the following three points.

The first is to control the alkalinity of the aqueous solution. The fluidized-bed boiler ash contains about 20% of lime, so the aqueous solution is made alkaline. This alkalinity is higher than that of foamed lightweight concrete. If the alkalinity of the water content adjusting agent is too high, a stripping phenomenon occurs when mixed with sludge, and ammonia, which is a malodorous component, is evaporated. For this reason, it is desirable to increase the mixing ratio of the foamed lightweight concrete waste material in order to suppress the evaporation of ammonia.

Secondly, it is necessary to secure the moisture adjusting ability. As described above, since the foamed lightweight concrete is autoclaved or steam-cured in its manufacturing process, it has a water content of 20% or more and is inferior in the water content adjusting ability to the fluid bed boiler ash without water. That is, it is desirable to increase the mixing ratio of the fluidized bed boiler ash when it is necessary to secure a high water content adjusting capability.

Thirdly, the lime content and silicic acid content of the composted fertilizer are controlled. The foamed lightweight concrete waste material and the fluidized bed boiler ash both contain lime content and silicic acid content, but their content ratios are different values. When the water content adjusting material of the present invention is used, the compost after fermentation becomes a fertilizer containing wollastonite content, but in order to control this wollastonite content to a desired value, foamed lightweight concrete waste material and fluidized bed boiler ash. It is desirable to determine the mixing ratio of.

In consideration of the above points, the mixing ratio of the foamed lightweight concrete waste material and the fluidized-bed boiler ash varies depending on the components of the sludge, the water content, and the like, but 1: 9 to 9: A volume ratio of 1 is desirable.

The particle size of the foamed lightweight concrete waste material used is preferably 4 mm or less from the viewpoints of handleability and performance as a water content adjusting material.

As will be described later, the moisture control material of the present invention also has a heavy metal adsorbing ability, but when the heavy metal content in the sludge to be treated is large and mixing in the waste water is a problem, It can also be fixed by the following method.

That is, an appropriate amount of phosphoric acid is added to the water content adjusting material of the present invention. The added phosphoric acid reacts with the calcium content in the moisture conditioner to pass through calcium hydrogen phosphate, and is transformed into hydroxyapatite by the curing effect of the heat of fermentation and ammonia contained in sludge as a catalyst. This hydroxyapatite easily undergoes a substitution reaction with heavy metal ions,
Fix heavy metals. By this method, the heavy metal content in the sludge can be reliably fixed. Phosphoric acid is the three major elements of fertilizer, and addition of phosphoric acid is also desirable for compost.

By the way, coal ash such as fluidized bed boiler ash contained in the moisture conditioner of the present invention is in the form of powder,
It is possible that handling problems will remain. In particular,
If the compost contains a large amount of powder, there is a problem of dust generation when it is applied to the soil. However, since coal ash such as this fluidized bed boiler ash contains a large amount of quick lime, it has a characteristic of hardening itself when water is added. Therefore, when added to sludge, by reacting with moisture in the sludge and hardening, even when adding coal ash such as powdered fluidized-bed boiler ash, the particle size of the obtained compost is large and Dust is not a problem when spraying. On the contrary, when the compost is used as a granular fertilizer, it can be easily performed by increasing the amount of coal ash such as fluidized bed boiler ash added.

When adding to the sludge, if a handling problem arises, it is possible to make the water content adjusting material of the present invention into a granular form in advance. That is, it is possible to granulate a mixture of foamed lightweight concrete into a powder form and mix it with coal ash such as fluidized bed boiler ash using a briquette or the like to obtain a granulated product having a desired particle size. At this time, coal ash such as fluidized bed boiler ash absorbs moisture contained in the foamed lightweight concrete and hardens. When the water content is insufficient, it is necessary to add water, but no binder is required for curing. Even in the case of the granules produced in this manner, a good moisture conditioner can be provided without impairing the features of the foamed lightweight concrete and coal ash such as fluidized bed boiler ash. The particle size of the granulated product is preferably about 1 to 4 mm for the same reason as above.

[0030]

[Function] The effectiveness of the granular particles of foamed lightweight concrete and the effectiveness of coal ash will be described below.

The foamed lightweight concrete has a porosity of about 50 to 90% and a maximum pore diameter of about 1 mm, and about 50% of them are fine pores having a pore diameter of 100 μm or less. Therefore, it has the advantages that it is highly breathable, has the ability to adsorb ammonia and organic substances that are malodorous components, and can provide an environment suitable for inhabiting fermenting bacteria. Further, since CaO is contained as the main component and the aqueous solution is made weakly alkaline, the occurrence of flies can be suppressed. Further, since SiO ₂ is contained as the main component, the compost after fermentation contains calcium silicate fertilizer, and there is a possibility of effective use of the compost.

However, regarding the water content adjusting ability,
Despite being able to hold twice as much water as its own weight
Since autoclaving or steam curing is carried out in the manufacturing process, the original water content is as high as 20% or more, and it does not have sufficient characteristics.

On the other hand, coal ash, which is ash obtained by burning coal at a high temperature, contains no water at all and is excellent in water content adjusting ability. Moreover, since it is a combustion ash of coal, which is a natural substance, it contains trace components such as manganese, magnesium, boron, and iron, which are effective as fertilizers.

Therefore, the mixture of foamed lightweight concrete and coal ash, or the moisture conditioner of the present invention obtained by further granulating the mixture, is excellent in the synergistic effect of the combined use of foamed lightweight concrete and coal ash. It exerts a water-regulating action, a fermentation promoting action, and a malodor preventing action.

A common feature of foamed lightweight concrete and coal ash such as fluidized-bed boiler ash is that they are porous bodies having very many fine pores. This allows
The water content adjusting material of the present invention adsorbs organic substances such as ammonia and lower fatty acids which cause a bad odor, and thus has the effect of suppressing the generation of a bad odor. It also has the effect of bleaching.

Further, the water content adjusting material of the present invention has an adsorbing capacity for heavy metals in addition to organic substances, so that the mixing of heavy metals into waste water can be suppressed.

[0037]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples.

Examples 1 and 2 As Example 1, as foam light-weight concrete waste material (particle size 4 m
m or less) and fluidized bed boiler ash in a volume ratio of 1: 1. As Example 2, foamed lightweight concrete waste material pulverized to 1 mm or less and fluidized bed boiler ash in a volume ratio of 1: 1.
The mixture obtained in 1 was further granulated, and those having a particle size of 2 to 4 mm were used, and each was added at a ratio of 20% by volume to the organic matter-containing sludge, and its water content adjusting performance was evaluated.

The evaluation was carried out by measuring the ammonia content as a malodor with a gas measuring tube and visually observing the fermentation state. The results are shown in Table 1.

Comparative Example 1 With respect to the organic matter-containing sludge to which the moisture conditioner was not added, the ammonia content was measured and the fermentation state was examined, and the results are shown in Table 1.

Comparative Example 2 Evaluation was performed in the same manner as in Example 1 except that sawdust was used as the water content adjusting material, and the results are shown in Table 1.

[0042]

[Table 1]

As is clear from Table 1, by using the moisture control material of the present invention, it is possible to prevent vaporization of malodorous components represented by ammonia in the fermentation treatment process of organic matter-containing sludge, and The fermentation period can be shortened significantly.

[0044]

As described above in detail, according to the moisture conditioner of the present invention, in the fermentation treatment of organic matter-containing sludge, the fermentation time is shortened to improve the treatment capacity and to generate a bad odor. A moisture conditioner having excellent properties such as effective prevention is provided.

According to the moisture conditioner of the present invention, the cost of the product can be reduced by using industrial waste, and the amount of waste can be reduced by effectively using the industrial waste. The social contribution of inventions is extremely high.

Particularly, according to the moisture conditioner of claims 2 to 4 and 6 to 8, a moisture conditioner of higher performance can be provided.

Claims (8)

[Claims] 1. A water content adjusting material for adjusting the water content of an organic matter-containing sludge, wherein the water content adjusting material comprises a mixture of foamed lightweight concrete particles and coal ash. 2. The particle size of the foamed lightweight concrete particles is 4
The moisture control material according to claim 1, wherein the moisture control material is less than or equal to mm. 3. The coal ash is at least one selected from the group consisting of pulverized coal boiler ash, stalker boiler ash and fluidized bed boiler ash.
Alternatively, the moisture conditioner according to item 2. 4. The mixing ratio of the foamed lightweight concrete granules and the coal ash in a volume ratio of 1: 9 to 9: 1, according to any one of claims 1 to 3. Moisture conditioner. 5. A water content adjusting material for adjusting the water content of an organic matter-containing sludge, which is obtained by granulating a mixture of foamed lightweight concrete powder and coal ash. 6. The water content adjusting material according to claim 5, wherein the particle diameter is 1 to 4 mm. 7. The coal ash is at least one selected from the group consisting of pulverized coal boiler ash, stalker boiler ash and fluidized bed boiler ash.
Alternatively, the moisture conditioner according to item 6. 8. The water content adjusting method according to claim 5, wherein the mixing ratio of the foamed lightweight concrete powder and the coal ash is 1: 9 to 9: 1 in volume ratio. Material.