JPS6158239B2 - - Google Patents

Description

[Detailed description of the invention]

This invention uses so-called river water sludge, which is a dehydrated cake of precipitate generated in the water treatment process of a river water purification treatment plant such as a water treatment plant, together with so-called wool sludge, which is a dehydrated cake of waste after dyeing wool. It relates to a method of solidification. <Prior art> Conventionally, there was no effective solidification technology for river water sludge, and most of it was simply dumped in landfills. However, as the amount of urban waste and industrial waste soil has been increasing steadily in recent years, methods for solidifying and treating them have begun to be considered. One idea was to introduce a large amount of cement-based or lime-based treatment agents, but if the target soil is highly water-containing, or When the organic content is high, the amount of processing agent is large, making it uneconomical, and high solidification strength cannot be expected. In addition, recently, waste soil has been solidified by producing ettrin guide (hydrated sulfate of calcium and aluminum) by mixing a reactive alumina-containing substance with a lime-based treatment agent (especially (Refer to Japanese Patent Publication No. 1986-92869), it is difficult to solidify unless the amount of alumina, lime, and gypsum, which are necessary coagulants for ettringite production, is reduced.
It had the disadvantage of not being economical. Moreover, since the solidified material solidified by the above-mentioned coagulant has a relatively low compressive strength, it is disadvantageous to use it as a landfill material. On the other hand, in factories that dye wool, there has been a desire for a good method for solidifying wool sludge, a dehydrated cake of waste produced during washing and dyeing of wool. As one method for this, it was devised to add auxiliary materials such as wastewater treatment sludge from the plating process and special adhesives to wool sludge, dry or bake it, and use it as a molded product for building materials, etc. (see Publication No. 48-46564), the processing agent and firing process are expensive,
Only a small amount of wool sludge can be used for special purposes, and it is not suitable for disposing of large amounts of wool sludge. <Object of the present invention> The present invention provides that when wool sludge to be disposed of is added to the Ettlin guide product and mixed,
By focusing on the fact that a solidified product with strong compressive strength can be obtained, eliminating the above-mentioned conventional drawbacks, and also processing wool sludge,
To provide a method for mixing and solidifying river water sludge and wool sludge, which can reduce the amount of coagulant used, improve economic efficiency, and obtain a solidified product with high compressive strength. <Summary of the present invention> In research on solidifying river water sludge, the present inventor discovered that a dehydrated cake of waste generated during washing and dyeing of wool, so-called wool sludge, is useful for solidifying river water sludge, and that it can be used as a solidifying product. The alumina used in the past is normally discharged as raw material waste at ceramic industry-related factories. It is composed of fine sand and low quality clay. As a result of experiments, he learned that so-called Kira could be used and completed this invention. In other words, an alumina-containing composition (Kira) and gypsum (calcium sulfate _CaCo2 ,
2H ₂ O) and slaked lime or quicklime powder to form a hydrated solidified product, which contains about 5 to 50 parts by weight of the river water sludge with a water content of about 60% and an alumina content of about 20 to 30 parts by weight. About 100 parts by weight of the above-mentioned Kira, about 5 to 30 parts by weight of gypsum, and about 2 parts by weight of slaked lime or quicklime.
It has been found that a mixed solidified product with the highest compressive strength can be obtained by mixing in a mixing range of ~30 parts by weight. Hereinafter, the configuration of the present invention will be explained based on experimental examples. First, a predetermined amount of river water sludge produced at a water treatment plant is mixed into a base containing powders of Kira, gypsum, and quicklime, and a solidified product is formed by a hydration reaction.The compressive strength of the solidified product (Kg/ cm ² ) is shown in Figure 1. Kira in this example has a sandy content of 7 and a low quality clay content of 3.
The chemical composition and particle size composition are as follows:
As shown in Table and Table 2.

【table】

[Table] The river water sludge in this example is from Kasugai Water Purification Plant in Nagoya City, and is as shown in Table 3.

[Table] This experiment consisted of 100 parts by weight of Kira (dried material) (hereinafter referred to as
It is simply abbreviated as part. ), 7 parts of gypsum, and 2 parts of quicklime, mixed with a predetermined amount of 0 to 10 parts of river water sludge with a water content of 60% to give a slurry concentration of 48%, which was then placed in a certain mold and cured. It was made into a hydrated solidified product. The compressive strength of the solidified product was measured after curing at room temperature for 4 weeks using an Instron testing machine in accordance with the JIS standard. As is clear from FIG. 1, as the amount of river water sludge added to the base increases, the compressive strength decreases significantly. From Fig. 1, it is impossible to add more than 2 parts of river water sludge to the base in terms of practical strength. However, when wool sludge is mixed with the mixture shown in Figure 1, which is unsuitable for practical use due to its low compressive strength, the compressive strength of the solidified product is surprising, as shown in Figure 2. will be increased as much as possible. In other words, Figure 2 shows 100 parts of Kira and 7 pieces of gypsum.
A predetermined amount of river water sludge (0 to 20
Part) shows the relationship between the blending amount of wool sludge and the compressive strength of each solidified product when mixed to form a hydrated solidified product. The wool sludge is discharged from a dyeing factory and contains soil and sand adhering to the wool, sheep excrement, dyes derived from the dyeing process, soap,
It is a slurry composition containing soda, lime, a polymer flocculant, sulfuric acid, etc. In this example, the wool sludge was previously dehydrated to a moisture content of 60%, and its pH was 12. The chemical composition of this wool sludge is shown in Table 4.

[Table] In addition, the compressive strength of the hydrated solidified material in Figure 2 was measured after the slurry concentration was 46%, placed in the specified mold, and cured in steam at 65°C for 3 days. . Next, add 5 parts and 10 parts of wool sludge to the base (100 parts of Kira, 7 parts of gypsum, 2 parts of quicklime).
River water sludge is added to each formulation.
The experimental results of mixing 20 parts to form a hydrated solidified product are shown in the third
In the figure, graph A shows the compressive strength when 5 parts of wool sludge is added, and graph B shows the compressive strength when 10 parts of wool sludge is added. As can be seen from Figure 3, when the amount of river water sludge blended exceeds 10 parts, the compressive strength decreases somewhat, but the compressive strength of the solidified product containing 20 parts of river water sludge is still sufficient for practical use. have. Furthermore, according to another experimental example, if 5 parts or more of wool sludge is mixed, hydration solidification with high compressive strength can be achieved even without mixing quicklime or slaked lime (Figure 4 shows the case where quicklime is used). I got something. The results of this experiment are shown in FIG. This formulation consists of 100 parts of Kira, 7 parts of gypsum, and 5 parts of river water sludge, and 5 to 20 parts of wool sludge of the above composition is mixed with a base that is not mixed with quicklime or slaked lime. (The curing conditions for the hydrated solidified product are the same as those in the experimental example shown in Figure 2.) Also, if the processing steps used to produce them are the same, the compositions of Kira and wool sludge will be roughly the same. Therefore, once the composition is investigated, it can be used as a source of the same composition from then on. <Action/Effect> As is clear from the explanation of the experimental examples, the present invention has the following effects on river water sludge and wool sludge:
A hydrated solidified product is obtained by adding an alumina-containing composition, gypsum, and quicklime or slaked lime. Since quicklime or slaked lime is added to form a solidified product, the compressive strength of the solidified product can be increased. The present invention uses 100 parts of Kira (containing about 20-30% alumina), which is discharged as ceramic raw material waste, and about 5 parts of gypsum.
30 parts of slaked lime or quicklime, about 5 to 30 parts of wool sludge, and about 5 to 50 parts of river water sludge with a moisture content of about 60%. Next, as an example of the present invention, a case will be described in which river water sludge (water content 62.5%), which is obtained by settling and dewatering sludge in a sedimentation tank of Oji Water Purification Plant in Nagoya City, is solidified. The river water sludge has an Ig.loss of 19.0%,
_{AI2O3 25.0} %, _SiO2 39.0% MgO 1.5%, CaO
11.0%, Fe ₂ O ₃ 4.5%, and PH13, which has almost the same composition as the sludge used in the experimental example described above. The wool sludge was collected on a different day from the same wool dyeing factory used in the above experimental example. In addition, the gypsum ( _CaSO4・
2H ₂ O) was used as a powder with a purity of 99.3%, which was a by-product from the desulfurization process of flue gas containing sulfur dioxide gas.
In addition, Kira was used that was discharged from a silica sand manufacturing factory in Seto City. The composition of Kira was almost the same as shown in Table 1 above. Then, put the predetermined amounts of each material into a mixer at the respective mixing ratios for ~ and control groups shown in Table 5, add an appropriate amount of water, and stir and mix to make the mixture into a slurry with a slurry concentration of 46%. . This slurry was then poured into a cylindrical mold with inner dimensions of 5 cm in diameter and 10 cm in height, and steam cured (3 days of steam curing at 65°C).
A solid was formed.

【table】

[Table] The compressive strength of each solidified product is shown in Table 6. As is clear from Table 6, the compressive strength of the solidified products in the sections ~ to which wool sludge was added was higher than that of the control section to which wool sludge was not added. The solidified material formed was used as a filler in an abandoned mine. The raw material cost of gypsum can be reduced by using by-products. Although Kira was used in this example, other alumina-containing compositions may be used in place of Kira. In this case, the alumina content is required to be about 20 to 30%, the same as Kira. Examples of alumina-containing compositions include kibushi clay and allofen (composition No. 7).
It is also possible to use Kanuma soil, etc., which contains (table).

[Table] According to the present invention, a solidified product with high compressive strength can be obtained by using wool sludge and slaked lime or quicklime. In addition, since the wool sludge that is disposed of as a solidifying agent for the river water sludge of the present invention is used, the raw material cost is low, and there is an advantage that it is possible to effectively dispose of these materials, which become a source of pollution and are difficult to dispose of when disposed of together with the river water sludge. According to the method of the present invention, a solidified product with high compressive strength can be obtained, so it can be used for reclamation of mining sites, unnecessary road falls, etc., for improving soft ground, for preventing gas generation in garbage landfills, and for reclamation of waste landfill sites. Can be used for improvements, etc.

[Brief explanation of the drawing]

The figures show the experimental results that form the basis of the present invention. Figure 1 is a graph showing the relationship between the amount of river water sludge mixed and the strength of the hydrated solidified product, and Figure 2 is a graph showing the relationship between the amount of river water sludge mixed and the strength of the hydrated solidified product. Figure 3 is a graph showing the strength of the hydrated solidified product when river water sludge is blended into a base containing wool sludge.
A graph showing the relationship between the blending amount of river water sludge and the strength of its hydrated solidified product. Figure 4 shows a reference example, and shows the strength of the hydrated solidified product when no lime agent is added to the base containing wool sludge. This is a graph showing.

Claims (1)

[Claims] 1. For river water sludge generated during river water purification treatment and wool sludge generated during wool washing and dyeing treatment, hydrated solidified product is produced by mixing Kira and gypsum, which are discharged as ceramic raw material waste, and slaked lime or quicklime. When making eggplant, the moisture content is approximately 60%.
about 5 to 50 parts by weight of the river water sludge, about 5 to 30 parts by weight of the wool sludge having a water content of about 60%, and about 100 parts by weight of the alumina composition having an alumina content of about 20 to 30%; A method for mixing and solidifying river water sludge and wool sludge, comprising mixing about 5 to 30 parts by weight of gypsum and about 2 to 30 parts by weight of slaked lime or quicklime.