JPH0732000A - Low-concentration sludge slurry floc settling agent, inorganic flocculant, organic polymer flocculant, and sludge residual soil method - Google Patents

Abstract

(57) [Summary] [Objective] A slurry of low-concentration sludge is improved into a dehydrated cake that can be applied as backfill soil, and a dehydrated cake with a stable low water content is produced. [PROBLEMS] To provide a method for making residual soil that produces a stable dehydrated cake from sludge, and a low-concentration sludge slurry floc sedimentation agent used in this method, which comprises an inorganic flocculant and an organic polymer flocculant.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a low concentration sludge slurry floc, a sedimentation agent inorganic flocculant, an organic polymer flocculant and sludge for separating bottom sludge and construction sludge from rivers and lakes into water and dehydrated cake. Regarding the method of making residual soil. Regarding sludge,
Define as follows. The low-concentration sludge refers to a sludge having a high water content ratio with an apparent specific gravity of raw sludge: 1.2 or less. The high-concentration sludge refers to a sludge having a low water content ratio, which is an apparent specific gravity of raw sludge: 1.2 or more. The sludge having a high water content refers to a low-concentration sludge having an apparent specific gravity of raw water of sludge: 1.2 or less. The low water content sludge refers to a high-concentration sludge having an apparent specific gravity of raw water of sludge: 1.2 or more. The same applies hereinafter.

[0002]

2. Description of the Related Art Conventionally, high-concentration sludge from river and lake sediments and construction sludge has generally been subjected to natural drying, lime
After treatment with a cement-based solidifying agent, the landfill or the final disposal site is used for disposal.Muddy water with a low concentration of water content removes sand and gravel with a vibrating sieving machine, and the fine mud containing organic matter in the mud water is removed. The particles are agglomerated and settled and separated, and only the sewage is removed.The flocs after settling and separation are disposed of by the above-mentioned method such as natural drying, lime / cement solidifying agent, etc. There is no known method for converting sludge to residual soil by improving dehydration cake that can be applied as backfill soil to produce a dehydrated cake with a stable low water content.

Conventionally, as inorganic flocculants, calcium chloride, polychlorinated aluminum, sodium aluminate,
Aluminum sulfate, ferrous sulfate and ferric sulfate are known. Conventionally, as an organic polymer flocculant, anionic polyacrylic acid sodium acrylate, polyacrylamide anion modified product, nonionic polyacrylamide, cationic polyacrylamide cation modified product and the like are known.

Conventionally, an inorganic flocculant and an organic polymer flocculant are added to a flocculant that adjusts the raw water of sludge to the same ionization tendency, and the flocculant is adsorbed by the flocculant by the neutralizing flocculating function and the crosslinking effect of the flocculant It is known how to make it.

[0005]

In the prior art, most of the bottom sludge and construction sludge of rivers and lakes have been treated with a high water content ratio, so that a large amount of water is solidified, and a large amount of water is solidified. Since it was transported while still containing water, it was economically problematic in terms of securing a treatment site.

[0006] In the prior art, there is no method for treating low-concentration sludge that improves mud water having a high water content after primary treatment by removing solids such as gravel into a dehydrated cake applicable as backfill soil. Had a point.

In the prior art, the addition of an inorganic flocculant or a polymer flocculant is used only for the function of neutralizing and aggregating suspended solids and the function of adsorbing and flocculating suspended solids by a crosslinking effect. There was an issue that it is difficult to establish a method for making residual soil that improves a dehydrated cake that can be applied as backfill soil by using a slurry of low-concentration sludge to produce a stable dehydrated cake with a low water content.

In the prior art, a stirring tank is generally used for the stirring reaction of the inorganic flocculant and the organic polymer flocculant, but since a pump is used to transfer sludge from the stirring tank, the flocs are cut by the impeller of the pump. However, there is a problem that the continuous operation is difficult because the dehydration property is deteriorated and the turbidity of the filtrate is often increased.

The present invention has been made in view of the above problems of the prior art, and an object thereof is to produce an excellent low-concentration sludge slurry floc and a sedimentation agent which produce a stable dehydrated cake. It is intended to provide an inorganic flocculant, an organic polymer flocculant, and a method for converting sludge to residual soil.

[0010]

[Means and Actions for Solving the Problems] In order to achieve the above object, in the present invention, a method for making residual sludge is to remove solid matters such as construction sludge and sand gravel of bottom sludge of rivers and lakes. Inorganic flocculant was added to the fine mud particles containing organic matter that form the low concentration sludge slurry, and the mixture was stirred through a stirring pipe to cause needle-like crystals, and then the organic polymer flocculant was added. The method is characterized in that, after stirring through a stirring pipe, a floc suitable for the specifications of a dehydrating device is formed to produce a dehydrated cake with a low water content.

A construction pump, a sludge pump for construction sludge, river / lake sludge,
Move from the original position by fluid transportation method such as pump dredging, rotary dredging, etc., pass through a vibrating screener to remove solids such as sand and gravel, adjust to low concentration sludge slurry, add inorganic flocculant, and sludge Needle crystallizes the components and P of the separated water
H is adjusted, and flocs suitable for a dehydrator are produced by an organic polymer flocculant to continuously and effectively dehydrate.

Further, in order to perform proper agitation after the addition of the coagulant, the muddy water sent from the concentration adjusting tank by the pump pressure is pumped on the way to the thickener before entering the belt press or filter press which is a dehydrator. It does not install, but it goes through a stirring pipe with a stirring baffle inside the pipe, so stir without breaking the flocs.

[0013] Further, by adding an inorganic flocculant such as Portland cement or blast furnace cement to fine mud particles containing organic matter such as construction sludge, river / lake sludge, etc. It forms fine mud particles containing lumps of organic matter in an irreversible and stable dehydrated cake. Further, since the dehydrated cake has Portland cement or blast furnace cement added thereto, it becomes a residual soil having an appropriate strength over time, and promotes solidification of the dehydrated cake.

Low-concentration sludge slurries such as construction sludge and river / lake sludge from which solid matters such as sand and gravel are removed, and Portland cement 5,000 to 20,000 ppm or blast furnace cement 5,000 to 20,000 ppm and aluminum sulfate 500 to An inorganic flocculant containing 10,000 ppm of the mixture as a main component is added.

Fine mud particles containing an organic substance that form a low-concentration sludge slurry are acicular crystals to become water-insolubilized crystal bodies that incorporate the fine mud particles and are adjusted to PH: 6.5-9. It Furthermore, if the pH is adjusted to 6.5 to 9,
A mixture of an organic polymer flocculant which is a polyacrylic amide copolymerization flocculation aid and an alkaline earth metal salt containing calcium chloride as a main component is added to promote flocking. The flocs are in a good state of needle-like crystals containing an appropriate amount of water and aggregate and precipitate.

A suitable stirring pipe is installed in the flocculation reaction line in order to prevent breakage of the floc mass by the pump in order to form the planned floc mass, promote a proper stirring reaction, and generate flocs.

The fine mud particles containing an organic substance aggregated in acicular crystals are composed of fibrous crystals. For filtration and dehydration effect by pressing, conventional inorganic flocculants such as calcium chloride, polychlorinated aluminum, sodium aluminate, aluminum sulfate, ferrous sulfate and ferric sulfate are used as auxiliary agents.

The main organic polymer flocculants include anionic polyacrylic acid sodium acrylate, polyacrylamide anion modified product, nonionic polyacrylamide, and cationic polyacrylamide cation modified product. An inorganic flocculant and an organic polymer flocculant are added to the flocculant that adjusts the sludge raw water to the same ionization tendency. Inorganic flocculant mainly composed of Portland cement or blast furnace cement and aluminum sulfate is intentionally added according to the adsorption floc method of floating substance by neutralization flocculation function and crosslinking effect of suspended matter. The inorganic flocculant adsorbs fine particles in muddy water and forms acicular crystals to promote coagulation and solidification, so it acts as a dehydrating aid that helps dehydration epoch-making, filtering, dehydrating and adjusting properties, dehydrated cake Solidification is promoted so that the soil becomes a residual soil with appropriate strength over time.

[0019]

【Example】

[Table 1] An example will be described with reference to FIG.

[Table 1] is a processing flow chart of the solid-liquid separation method for construction sludge and bottom sludge from rivers and lakes.

In [Table 1], the sediment sludge from rivers and lakes is dredged to a predetermined position by pumping, and the dust removal device is allowed to pass by continuous pressure feeding to remove wood chips, metal objects, gravel, and other substances that interfere with muddy water treatment. Similarly, for construction sludge such as bentonite sludge and mud thrusting and shield construction methods, materials generated from the site are continuously fed under pressure to a dust remover, and then dust is stored in a raw water tank and agitated so that minute gravels do not settle.

After the raw water tank has reached a certain amount, the pump (A) passes a liquid cyclone and a vibrating sifter to remove gravel of 0.2 mm or more, and sludge after separating the gravel is pumped (B). ), It is stored in the concentration adjustment tank and adjusted to a predetermined concentration within a specific gravity of 1.05 to 1.20. If the specific gravity is high, the water content is adjusted, and if the specific gravity is lower than expected, the amount of the flocculant liquid is adjusted.

The sludge whose concentration has been adjusted by the concentration adjustment tank is transferred to the floc generation step by the pump (C),
The sludge pumped from the pump (C) is composed of a pipeline. First, a predetermined amount of inorganic coagulant is injected from the middle of the pipeline, stirred by a stirring pipe (A), and then an organic polymer coagulant is injected. After that, large flocs are generated by the stirring pipe (B).

At this time, the coagulant is blended in such a manner that the inorganic coagulant A is Portland cement 5,000 to 20,000 p.
pm or blast furnace cement 5,000 to 20,000 pp
by a low-concentration sludge slurry floc settling agent consisting of an inorganic flocculant A containing a mixture of m and 500 to 10,000 ppm of aluminum sulfate as a main component, and a polyacryamide amide copolymer flocculant which is an organic polymer flocculant. To do.

The flocs are solid-liquid separated by a belt press or a filter press in consideration of treatment scale, turbidity of drainage, drainage standards, and the like, and a dehydrated cake having a low water content ratio and a filtrate that meets environmental standards are discharged.

[0024]

Since the present invention is constructed as described above, it has the following effects.

Construction sludge and bottom sludge from rivers and lakes are generally in a neutral region around PH7, and the coagulant is mixed with Portland cement 5,000 to 2 as an inorganic coagulant.
50,000ppm or blast furnace cement 5,000-2
50,000 ppm and aluminum sulfate 500 to 10.0
Alkaline inorganic flocculant, which is composed of a low-concentration sludge slurry floc settant consisting of an inorganic flocculant mainly composed of a mixture of 00 ppm and a polyacryamide copolymer coagulant which is an organic polymer flocculant. Portland cement or blast furnace cement is mixed with aluminum sulfate, which is an acidic inorganic coagulant, according to the properties of sludge, and the floc formation of polyacryamide amide copolymer coagulant, an organic polymer coagulant, can be performed without any problem. Therefore, the filtrate after solid-liquid separation can be kept in a neutral region.

Further, since the flocs are produced by the above-mentioned composition and the mixture is agitated by the agitation pipe, the flocs can be surely produced, the dehydration property is dramatically improved as compared with the conventional method, and the flocs have a water content ratio: It can be dehydrated to 80% or less. The dehydrated cake retains moderate strength in a short time due to the hardening properties of Portland cement or blast furnace cement and aluminum sulfate, which is an acidic inorganic coagulant, so that it remains as irreversible and stable soil even if it is rained or flooded, as with ordinary earth and sand. It can be used as backfilling or laying material, and can be recycled or resources can be made effective.

Further, the action of the inorganic flocculant and the organic polymer flocculant produces a dehydrated cake containing heavy metals of sludge and malodorous molecules, so that the filtrate is a stable drainage that conforms to environmental standards. You can get it.

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[Procedure amendment]

[Submission date] July 14, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Title of invention

[Correction method] Change

[Correction content]

Title of invention Low concentration sludge slurry floc settling agent,
Inorganic flocculant, organic polymer flocculant, and sludge sludge making method

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B01D 21/01 108 9042-4D B09B 3/00 ZAB

Claims (4)

[Claims] 1. A low-concentration sludge slurry floc settling agent comprising an inorganic flocculant and an organic polymer flocculant, which is used in a method for leaving soil for producing a stable dehydrated cake from sludge. 2. The inorganic flocculant constituting the low concentration sludge slurry floc settling agent according to claim 1, is 5,000 pp.
An inorganic flocculant composed mainly of a mixture of Portland cement of m to 20,000 ppm or blast furnace cement of 5,000 ppm to 20,000 ppm and aluminum sulfate of 500 ppm to 10,000 ppm. 3. An organic polymer flocculant, wherein the organic polymer flocculant constituting the low-concentration sludge slurry floc settling agent according to claim 1 comprises a polyacryamide copolymer flocculation aid. 4. The inorganic agglomerate according to claim 2, wherein fine mud particles containing organic matter forming a low-concentration sludge slurry are obtained by removing solid matters such as construction sludge and sand gravel of bottom sludge from rivers and lakes. The agent is added, and the mixture is stirred through a stirring pipe to form needle crystals, and then the organic polymer flocculant according to claim 3 is added, and the mixture is stirred through a stirring pipe, and then the dehydration device has a specification. A method for sludge remaining soil formation, which comprises forming adapted flocs and producing a dehydrated cake having a low water content.