JPS6087813A - Coagulating, settling and solidifying agent - Google Patents

Abstract

PURPOSE:To obtain an agent for coagulating, settling, and solidifying treatment of sludge capable of increasing settling and solidifying speed or increasing the strength of settled and solidified product using a cementitious solidifying agent in combination with org. polymeric coagulating agent. CONSTITUTION:A coagulating, settling, solidifying agent is obtd. by adding a fine pulverous org. polymeric coagulating agent comprising acrylamide/sodium acrylate copolymer to a cementitious solidifying agent contg. a chemical compsn. of ettringite precursor as shown in the table. The org. polymeric coagulating agent should be selected depending on the object to be treated. Anionic or nonionic coagulant may be suited for dredged sludge or muddy water of urban engineering work. On the other hand, cationic coagulant may be suited for org. sludge such as excess sludge of sewage and night soil treating facility or digested sludge, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coagulation sedimentation solidification treatment material for dredging, urban civil engineering mud, organic sludge, etc. in sewage and human waste treatment facilities.

Conventional methods for coagulating, settling, and solidifying sludge such as organic sludge in dredging waste, urban civil engineering mud, and sewage human waste treatment facilities include adding an anionic, nonionic, or cationic polymer flocculant to the sludge. A method of solidifying the flocculated sludge by adding a cement-based solidifying agent to the flocculated sludge, or a method of solidifying the flocculated sludge by adding a cement-based solidifying agent to the flocculated sludge.
A method of solidifying by adding a solidifying agent has been used.

However, these methods have drawbacks such as complicated treatment steps, slow sedimentation and solidification rate, and low strength of the sedimentation and solidification.

The present inventors completed the present invention as a result of further investigation in view of these conventional drawbacks.

That is, the present invention is a coagulation-sedimentation-treated material prepared by blending a finely powdered polymer flocculant with a cement-based solidification material containing an Ettringai precursor composition.

The cement-based solidifying material in the present invention is a cement I-based solidifying material containing a ringite precursor composition, and may be any type of solidifying material as long as it can solidify the target sludge. In order to coagulate and settle the solid content and then effectively solidify the sludge, it is preferable to use a solid (71) made of a composition that produces a large amount of ettringite through a hydration reaction.

The reason for this is, first of all,
This is because, as its chemical formula shows, 103.3CaSO4.32112 ol has 4586 of its own weight as water, and has a remarkable effect on reducing the water content of sludge. In addition, since Ku-1 Ringai-1 is a needle-shaped crystal, even in sludge with a high moisture content, the needle-shaped crystals of Ku-I-Ringai-1 form bridges between soil particles, binding the soil particles together and developing strength. It is possible. In addition, in general cement 1, solidification is hindered when monoacid coexists, but the hydration reaction that forms cement 1-ringite is less affected even in the presence of organic acids, and it is difficult to combine with organic polymer flocculants. Combined use is ijj function.

Furthermore, in order to generate Ca 24. and Ringai 1-, Ca 24. The presence of cations such as Δ13+ and anions such as OI do and SO7 ions is greatly related to the flocculation-sedimentation effect shown later, and produces an effect similar to that of adding an inorganic flocculant. is bringing.

As the organic polymer flocculant to be blended, if it is a powder, one ordinarily used one can be used, but it must be selected depending on the object. Anionic or nonionic flocculants are preferable for dredging, river mouths, urban civil engineering mud, etc., such as polyacrylamide, partial hydrolyzate of polyacrylamide, and copolymer of acrylamide and acrylic acid.

On the other hand, when considering dehydration and solidification treatment of organic sludge such as sewage, surplus sludge from human waste treatment facilities, and digested sludge, cationic sludge is preferred, such as dialkylaminoalkyl (meth).
Homopolymers of tertiary salts or quaternary ammonium salts of acrylate-1 or copolymers with other vinyl R-mers,
Examples include cationic modified polyacrylamide.

The polymer flocculant to be blended must be a fine powder, and its particle size is preferably 0.3+u or less, more preferably 0.05 to 0.3 fins. When the particle size of the powder exceeds 0.3 fins, the dissolution rate of the polymer flocculant in water becomes slow and there is a problem that the flocculation effect is not expressed immediately after addition. Also, add polymer flocculant to 0.05 +
If the product is finely pulverized to less than n, polymer chain shearing will occur during pulverization, which will lower the molecular weight and reduce flocculating performance. It is also possible to maintain performance by increasing the amount -V.

As for the method of finely pulverizing the polymer flocculant, if it is a dry pulverizing method, a normal fine pulverizing method such as a screen mill or a voluminator can be used.
The temperature is preferably 80°C or lower, more preferably 60°C, since crosslinking of the polymer will proceed and deterioration will occur if exposed to
It is preferable to use a method of finely pulverizing the powder while cooling. It is also possible to carry out frozen grinding.

The polymer flocculant is a relatively hygroscopic substance, and the cement-based solidifying material dislikes moisture, so it is necessary to grind it in a state where it does not absorb moisture.

The blending amount of the polymer flocculant is subject to ', r! Although it varies depending on the quality, concentration, and pH of the turbidity or sludge, it is generally 0.0% for cement-based solidification. (1001% by weight ~ 1゜(
] It is preferable to blend within the range of % by weight. If the amount of flocculant added is too small, no flocs will naturally be formed, but if it is too large, the flocculation performance will deteriorate due to repulsion between the polymers.

When the concentration of sludge becomes high, the pH goes out of the optimum range, or the amount of organic sludge increases, it is possible to maintain performance by increasing the blending amount.

Regarding the mixing method of polymer coagulant and cement solidifying agent, the usual mixing method is horizontal cylindrical mixer, V-type mixer,
Mixing methods using double conical mixers, ribbon mixers, conical screw mixers, etc. are adopted, but since the amount of polymer flocculant blended is small, it is necessary to mix as uniformly as possible. .

Since the bulk specific gravity of the polymer flocculant and the cement 1 solidification material are different, it is necessary to avoid a mixing method that causes classification in the mixing device.

The coagulation-sedimentation solidification treatment material of the present invention is directly added to the target suspended matter or sludge to cause flocculation and solidification, but the addition method, amount, etc. (This is done in the same way as 1.

The coagulation-sedimentation solidification treatment H of the present invention may contain an accelerator that promotes the solidification of cenone 1. The accelerator has the effect of controlling the calcium ion concentration in the hydrated liquid phase, the effect of removing the hydrate formed around the Shichimen 1 particle, and the effect of rapidly forming ettringite etc. have.

Examples of the accelerator include calcium chloride, monolium carbonate, calcium aluminate, etc. In addition, the coagulation-sedimentation-solidified material of the present invention may contain calcium hydroxide produced in the solidified material after the coagulation-sedimentation treatment. A neutralization charge for neutralization can also be added. By adding a neutralizing material, the alkalinity of the soil can be reduced, making it suitable for the growth of 116 species.

Examples of the neutralizing material include aluminum sulfate, slag powder, and activated silica. The coagulation sedimentation solidified material of the present invention has the following effects.

(1) Since flocculation and sedimentation and assimilation are performed at the same time, there is no need for a device to suspend and transport the flocculant. Solidification treatment in ice is also possible.

(21 A disadvantage of using an FA-terminated polymer flocculant is the formation of mako.When dissolving the powdered polymer flocculant, it is possible to achieve a relatively /8 solution by dispersing it little by little in water. However, if the powder is put into water all at once, the surface of the powder becomes wet and extremely sticky, causing the powder to coagulate and form a glue-like mass, resulting in so-called mako.

This lump cannot be broken by stirring, etc., and it is impossible to completely melt the lump even after stirring for several hours or days, which is very uneconomical and tends to stick to the inside of the melting tank. This causes various problems such as difficulty in peeling off.

In order to prevent the occurrence of mako, it is necessary to disperse the particles as uniformly as possible during the initial stage of melting, and to prevent the particles from adhering to each other.
However, in the case of the coagulation and solidification treatment material of the present invention, a large amount of cement acts as a dispersion medium, and particles of the polymer flocculant are less likely to adhere to each other, so it is possible to prevent the occurrence of lumps.

In addition, the basic components in cement improve dispersibility,
Since dissolution is promoted, it is possible to prevent the occurrence of mako.

(3) Since the aqueous solution of the polymer flocculant has a very high viscosity, it is referred to as the flocculant solution) 12! Although uniform mixing with turbidity or sludge is quite difficult, in the present invention, flocculating performance is developed after mixing with the mud, and a large amount of inorganic salts in cement 1 exhibits a viscosity-reducing effect, so that the coagulant and sludge can be mixed together. It is extremely easy to mix.

In addition, when dewatering is performed using a dehydrator, the coagulated sedimentation solidified material acts as a dehydration aid and forms so-called water, increasing the rate of water movement within the sludge layer and reducing the water content.

(4) Cement 1 type solidification shrine is F1. The core of J-Tsuku is that even difficult-to-treat wastewater with a high organic matter content increases the sedimentation rate of the drain and improves the clarity of the supernatant.

(5) ′ in water. Y! ．． Turbid matter generally has a negative charge (!!J
Therefore, it is common practice to neutralize the surface charge of dredging sludge, urban civil engineering mud, etc. with inorganic salts such as sulfuric acid or polyaluminum chloride, and then add an anionic or nonionic polymer flocculant. However, in the present invention, a large amount of inorganic salt in the cement-based solidified material neutralizes the surface charge, so there is no need for inorganic salt for fjf.

(6) It is a well-known fact that when a cationic flocculant and an anionic flocculant are used in combination, flocculating performance and dewatering performance are improved for the same reason as stated in (5). When a cationic flocculant and an anionic flocculant are simultaneously melted in one dissolution tank, a polyion complex is generated and becomes water-insoluble, so two dissolution tanks are required, but in the case of the present invention, dissolution and flocculation are required. Since these are thought to occur almost simultaneously, their combined use is easily possible.

(7) A solution of a polymer flocculant does not deteriorate over time due to light, temperature, dissolved oxygen, etc., but in the present invention, since it is melted and used at the same time, no deterioration occurs.

Next, the present invention will be explained in more detail with reference to Reference Examples, Examples, and Comparative Examples.

Note that the percentages on each side mean percentages by weight.

The polymer coagulant and cement-based hardening material used were as follows.

Polymer & 2 Building Agent Anionic polymer flocculant (hereinafter referred to as flocculant A) Composition Polymer flocculant consisting of acrylamide/sl-lium acrylate copolymer Cationic polymer flocculant 71'lJ (hereinafter referred to as flocculant B) (hereinafter referred to as solidifying material ■), a polymer flocculant consisting of a quaternary salt of methyl chloride of N,N-dimethylaminoethyl methacrylate-I/acrylamide 1' copolymer (hereinafter referred to as solidifying material ■) Composition Cement 1 solidification sample ■ (hereinafter referred to as assimilated material ■) Chemical composition reference example 1 A comparison of the dissolution rate according to the powder particle size of flocculant A at a melt concentration of 0.
It was performed at 1%.

The results are shown in FIGS. 1 and 2.

Reference Example 2 A case where a coagulation sedimentation solidification treatment material in which a finely pulverized product of flocculant A is mixed with a solidifying agent ■ is dissolved in a beaker under the following conditions, and a case where a finely pulverized product of flocculant A and a solidifying agent ■ are added separately and melted. The presence or absence of mako formation and Brookfield viscosity were measured.

The results are shown in Table 1.

Melting concentration: flocculant 0.1% Dissolution time: 3 hours *Since cement flocs were formed, the viscosity of the supernatant liquid after floc settling was measured. ``Example 1 A flocculation-sedimentation solidification treatment material prepared by mixing a finely powdered flocculant A and a solidification material ■ or ■ is added to a 5% kaolin suspension in a 500ml cylinder, and after mixing 5 times, it is allowed to stand still and allowed to settle. Velocity measurements were taken.

Experiments were conducted by changing the amount of flocculant and cement solidifying agent, the amount of coagulation sedimentation solidifying agent added, the type of solidifying agent, etc. The results are shown in Table 2.

From this result, it is clear that the coagulation-sedimentation and solidification-treated material shows the effect immediately after addition, and has a remarkable 6-year effect compared to the product without the addition of a coagulant.

Comparative Example A 0.1% aqueous solution of coagulant A was prepared separately, and this and solidifying agent ■
The sedimentation rate was measured in the same manner as in Example I when (1) and (2) were added separately to a 5% kaolin suspension. The results are shown in Table 3.

Table 2 Table 3 Example 2 and Comparative Example 2 Align (3Ca 0 ・3A 120i ・Ca 5
A solidifying material that produces a large amount of ettringite through a hydration reaction, consisting of O4), anhydrous plaster (CaSO4), etc.
A solidified material was prepared by adding flocculant A to the mixture.

Add 10% of this solidified material to kaolin wastewater with a water content of 90%.
After stirring, the mixture was filled into a plastic bag with an inner diameter of 5 LJnφ to a height of 130 marks, and the height of the settling surface after 3 hours and the unconfined compressive strength at a material age of 70 were measured. The results are not shown in Table 4. For the compressive strength of Φ111, a specimen was molded from the - part and lower part of a solid body and subjected to the test.

Table 4 *1: Ordinary Portolan I Cement [- From the above results, it is possible to quickly settle and solidify the mud by using the flocculant when a cement-based solidification agent and an organic polymer flocculant are used in combination.

In addition, the moisture content of the solidified substance decreases due to sedimentation, so it becomes solid (IZ
It is also highly advantageous in terms of strength. On the other hand, those to which Yen-ichi-hi wood is added alone have poor settling properties, high moisture content of the solidified material, and low strength. Furthermore, when ordinary cement and a flocculant are used in combination, although the settling property is the same as that of the product of the present invention, the flocculant interferes with the hydration reaction of the cement, so almost no strength is developed.

Example 3 and Comparative Example 3 0.6% of flocculant B was added to the solidified moon to prepare a flocculated sedimentation solidified material. P II 5.6, SS 2790
0 ppm of sewage digested sludge with 1.2.3
．． After adding 4%, stir at 500 rpm for 30 seconds to 0.84 k
Pressure dehydration was performed at a pressure of g/cJ, and the water content was measured. In addition, the sludge after dewatering was molded in a cylindrical mold of 5 cmφ×]Ocm to obtain a material age of 30 - - axial compression strength (Example 3
).

In addition, 300 ppm of flocculant B alone was added to the sludge,
The unconfined compressive strength was measured in the same manner (Comparative Example 3).

The results are shown in Table 5.

Table 5 As shown above, if the coagulation-sedimentation solidification treatment material of the present invention and dewatering operation are used together in the treatment of sewage sludge, the water content of dewatered sludge can be significantly reduced, and the solidification strength can also be sufficiently demonstrated. processing becomes easier. Furthermore, the use of the coagulation-sedimentation and solidification treatment material of the present invention does not require any special equipment other than the treatment material supply device.

[Brief explanation of drawings]

Figures 1 and 2 are graphs showing the dissolution rate of the flocculant depending on the powder particle size in Reference Example 1.
Flocculant A2 with a particle size of 0.833 am or more... Flocculant A3 with a particle size of 0.495 to 0.833 m++...
...Flocculant A4 with a particle size of 0.351 to 0.4951M.
...Flocculant A5 with a particle size of 0.246 to 0.351 mm...Flocculant A with a particle size of 0.175 to 0.246 +U Patent applicant Chichibu Cement, Toagosei Chemical Industry Co., Ltd. I. Motooka Tsusho Co., Ltd. Mei/JJ Suirin 4-壓 (-+n) Nu 2 凰Recruitment Gun Igari (Familiar)

Claims (1)

[Scope of Claims] 1. A coagulation-sedimentation solidification material prepared by blending a cement 1-based solidification material containing a precursor composition with a microorganism-based polymer flocculant. 2. Yes; The coagulation, sedimentation, and solidification treated material according to claim 1, wherein the particle size of the multi-system polymer flocculant is 0.3 mm or less. 3. The coagulation-sedimentation solidification material according to claim 1, wherein the amount of organic polymer flocculant added to the cement solidification material is 0.000 J to 1.0% by weight.