KR100860017B1 - Soil aggregate composition for civil engineering and construction materials using process sludge and manufacturing method thereof - Google Patents

Abstract

A soil aggregate composition using process sludge is provided to be usable as fine aggregate of construction materials, and filling materials of pavement blocks, embankment blocks, lightweight blocks, or clay blocks. A soil aggregate composition for civil engineering and construction materials using process sludge includes 100 parts by weight of sludge, 20-50 parts by weight of a coarse pozzolan material(reject ash) having a specific surface area of 2,000 cm^2/g or less, 10-40 parts by weight of fly ash having a specific surface area of 3,000-3,500 cm^2/g, 5-35 parts by weight of process sludge produced as byproducts from the production process of polyesters, artificial marble, and other chemical products, 1-5 parts by weight of ferrous sulfate, and 10-25 parts by weight of at least one inorganic binder selected from the group comprising calcium oxide, blast furnace slag powder, portland cement, and mixtures thereof. The sludge is water treatment sludge, sewage sludge, or a mixed sludge thereof. When the water treatment sludge and sewage sludge are individually used, the sludge is used in an amount of 100 parts by weight. When the mixed sludge is used, the water treatment sludge and sewage sludge are used in amounts of 10-90 parts by weight, respectively. Further, an average diameter of the fly ash is 30 to 50 mum.

Description

SOIL AGGREGATE COMPOSITION FOR CIVIL ENGINEERING AND CONSTRUCTION MATERIALS USING PROCESS SLUDGE AND MANUFACTURING METHOD THEREOF}

The present invention is a process sludge and sludge which can be preferably used as a soil aggregate, which is used as a filling material for civil engineering materials such as cover materials, fill materials, and building materials, fine aggregates, sidewalk blocks, raft blocks, lightweight bricks, or clay bricks. It relates to a soil aggregate composition for civil and building materials using and a manufacturing method thereof.

In general, in order to recycle sludge with high water content, the solidified material prepared by mixing fly ash, quicklime, cement, etc. was used as a landfill material for landfill. However, due to the strong alkali-based material, ammonia gas is generated in a large amount, and a long curing period occurs.

Subsequently, in the case of the method of preparing a solidifying agent, a method of neutralizing the powder with strong alkali-based materials using 95 to 98% of strong acid and waste acid was proposed. However, due to the rapid exothermic reaction and the generation of harmful fume gas such as hydrogen sulfide in the neutralization reaction, there are many potential problems, such as the need for emission gas regulation or a new prevention facility.

Meanwhile, in regions where large sludge solidification plants such as metropolitan landfills are scarce, local governments are struggling to prepare countermeasures, such as a lack of places for disposal due to the regulation of ocean dumping. Therefore, there is an urgent problem in securing a new treatment method or a recycling treatment facility and treatment plant suitable for local characteristics, which has been advanced from the existing solidification treatment method.

Sludge produced in Korea is purified waste sludge produced by tap water production, sewage and wastewater sludge produced in sewage and wastewater treatment plants, and sediment sludge produced by natural sedimentation on rivers, lakes and shores. have. Among them, purified water and sewage sludge are by-products generated by the final agglomeration and sedimentation during the treatment process, and have a very high moisture content, difficult water desorption, and are contaminated with heavy metals. In addition, it contains a large amount of organic matter, and if left unattended, it easily decomposes, causing severe odors, polluting the surrounding environment, and causing inhalation and headache when vomiting.

Most of this sludge is dependent on ocean dumping, incineration or simple landfilling. In the case of ocean dumping, it is recognized as the main culprit of the deepening destruction of the marine ecosystem, and the dumping of marine dumping will be banned in 2011. In addition, incineration causes social problems by releasing so-called highly toxic carcinogens such as dioxin, formaldehyde, and acrolein due to incomplete combustion, which is not suitable for the situation of Korea where energy resources are scarce due to huge construction and maintenance costs. . And even in the case of landfill, it is difficult to secure landfill, and complaints related to leachate problems, pathogenic bacteria, pest eggs, dust generation, and odor spread are not easy to handle. Composting efforts using sewage sludge also restrict urban sewage sludge from being used as compost for fear of harmful substances affecting people through crops.

The present invention complies with waste regulations that prohibit the direct reclamation of organic sludge containing a large amount of water and minimizes the generation of harmful gases such as hydrogen sulfide, which is inevitably generated during the neutralization reaction by replacing strong acidic materials with process sludge. It aims to stabilize, solidify, detoxify and cleanse purified water and sewage sludge at low disposal costs by using waste resources, which are general wastes of workplace discharge facilities around the facility.

In addition, this paper proposes a method of manufacturing soil aggregate using the same, and uses it to cover wastewater and sewage sludge that can be recycled into abandoned landfills, dangerous landfills, or daily landfills of landfills. The purpose is to develop soil aggregate for refining, ground reinforcement, land improvement and building materials.

At present, various types of fly ash, bottom ash, and incineration ash, which are useful for recycling, are being reused in large part due to the government's active recycling policy, but a large amount is still being discarded or disposed of in landfills.

In addition, process sludges that cause various odors are also subject to evasion and do not have a place to be treated.

In addition, water purification sludge is treated as sewage sludge, so the research and development is very insufficient, and marine dumping is banned as of January 1, 2007, and it is used as some cement raw materials or relies on landfill and mixed landfill.

Therefore, Applicant uses the process sludge, which is a waste material that can effectively replace the high-purity strong acidic material, which is the solidification treatment material, to make the reactive material usable by adding the pozzolanic material and a small amount of ferrous sulfate, and to the mixed additive mixed with the inorganic binder. Recycled soil aggregates are prepared by mixing purified water sludge depending on ocean dumping or landfill, or by mixing the mixed additives in a proportion to the composition of purified water sludge, sewage sludge and inorganic minerals. It aims to prevent secondary environmental pollution and to replace scarce aggregate and soil at low cost. In addition, the present invention proposes a method for producing soil aggregate, which can be usefully used as a raw material for dry materials by selectively storing and drying only the final processed material containing a lot of mineral inorganic materials.

The present invention covers the use of purified water, sewage sludge, ground reinforcement, land improvement, and construction, which can be recycled as abandoned landfills of abandoned abandoned mines, hazardous construction sites, or as daily cover materials for landfills. It aims to provide the earth aggregate composition for materials.

In another aspect, the present invention to minimize the generation of harmful gases such as hydrogen sulfide, and to provide a method for producing a soil aggregate composition using purified water and sewage sludge at a low treatment cost, using waste resources that are the general waste of the plant discharge facility around the recycling facility. The purpose.

In order to achieve the above object, the present invention

In the earth aggregate composition for civil engineering and building materials using process sludge and sludge, based on 100 parts by weight of sludge

20 to 50 parts by weight of a pozzolanic substance (Reject Ash, residue) having a specific surface area of 2,000 cm ² / g or less,

10 to 40 parts by weight of fly ash having a specific surface area of 3,000 to 3,500 cm ² / g,

5 to 35 parts by weight of process sludge produced as a by-product from polyester, artificial marble and other chemical products

1 to 5 parts by weight of ferrous sulfate, and

10-25 parts by weight of one inorganic binder selected from the group consisting of calcium oxide, blast furnace slag powder, portland cement and mixtures thereof
Including;
The sludge is purified sludge, sewage sludge and mixed sludge thereof,

When using purified water and sewage sludge alone, 100 parts by weight is used, and in the case of mixed use, process sludge and sludge civil engineering using 10 to 90 parts by weight, and sewage sludge to 10 to 90 parts by weight. It provides a soil aggregate composition for building materials.

In another aspect, the present invention is a method for producing a soil aggregate composition for civil engineering and building materials using a process sludge and sludge,

(S1) 20 to 50 parts by weight of a pozzolanic substance (Reject Ash) of coarse powder having a specific surface area of 2,000 cm ² / g or less and 10 to 40 parts by weight of fly ash having a specific surface area of 3,000 to 3,500 cm ² / g. A first mixing step of preparing a first mixture;

(S2) a second mixing step of preparing a second mixture by mixing 5 to 35 parts by weight of process sludge and 1 to 5 parts by weight of ferrous sulfate, which are produced as by-products in polyester, artificial marble, and other chemical product manufacturing processes;

(S3) 3 to prepare a third mixture by mixing the first mixture and the second mixture with 10 to 25 parts by weight of one inorganic binder selected from the group consisting of calcium oxide, blast furnace slag fine powder, portland cement, and mixtures thereof. Tea mixing step;

(S4) a fourth mixing step of preparing a fourth mixture by mixing the third mixture with 100 parts by weight of sludge; And

(S5) curing step of curing the fourth mixture

It provides a method for producing a soil aggregate composition for civil engineering and building materials, including.

Process for producing soil aggregate using the process sludge and the purified water and sewage sludge according to the present invention has the following effects.

First, resource sludge can be saved by using process sludge, which relies on expensive incineration and ocean dumping, as an alternative to acidic substances that suppress odor and harmful gas generation.

Second, although it can be used as cover material, horticultural soil, land material (soil improver), landfill material, and roban material, it is not widely recognized as a recyclable material due to the distorted idea and lack of research that it is similar to sewage sludge. Wastewater sludge that has been discarded can be effectively solidified sewage sludge with high moisture content and high harmful components.

Third, the method is superior to the conventional method in terms of water content reduction, odor removal, removal of harmful substances, economical efficiency, processing efficiency, process simplification and continuity, and can be used in accordance with regional characteristics considering transport distance and by-product generation location. There is this.

Fourthly, in terms of using wastes discarded, it is environmentally friendly, has a very short curing period, and has the effect of refining the final mixture.

Hereinafter, the present invention will be described in more detail.

Sludge referred to throughout this specification includes purified sludge and sewage sludge, unless otherwise defined.

As used throughout this specification, '%' means weight percent unless otherwise specified.

Soil aggregate composition according to the present invention using the water purification and sewage sludge in order to manufacture soil aggregate for cover, fill, ground reinforcement, land improvement and construction materials, using a water content control function, process sludge to lower the moisture content Various mixtures with pH control function, deodorization function to remove odor, harmful substance removal function to remove heavy metals and harmful substances, and strength strengthening function to strengthen strength are used.

Such mixtures include pozzolanic materials, fly ash, process sludge, ferrous sulfate and an inorganic binder.

Composition

Hereinafter, each composition will be described in more detail.

At this time, the content range of each composition described below is an optimum range for maximizing each effect obtained when using each composition and the synergy effect obtained by mixing with other compositions. Not get

The soil aggregate composition according to the present invention is prepared with sludge as a main component.

The sludge may be used alone or in combination with purified water and sewage sludge, and mixed with inorganic minerals if necessary. Specifically, the sludge is purified sludge alone; Water and sewage sludge mixing; Mixtures of purified sludge with inorganic minerals, sewage sludge with inorganic minerals are possible.

More specifically, each of the purified water and sewage sludge is used at 100% by weight, and when used alone, a mixture of 50 to 85% by weight of purified water sludge and 15 to 50% by weight of inorganic minerals; A mixture of 50 to 85% by weight of sewage sludge and 15 to 50% by weight of inorganic minerals; And a mixture of 30-50 wt% of purified sludge, 30-35 wt% of sewage sludge and 15-40 wt% of inorganic minerals.

Inorganic minerals include feldspar, pyrophillite, silica, silica and potite stone and Sericite mines. Waste stone powder generated as a by-product from the mill process, Red Mud, a by-product of aluminum hydroxide manufacturing process, and the like.

For such sludge, in the present invention, a pozzolanic substance (Reject Ash, Residual) having a specific surface area of 2,000 cm ² / g or less is used in an amount of 20 to 50 parts by weight based on 100 parts by weight of the sludge, and the specific surface area is 3,000. Fly ash of ˜3,500 cm ² / g is used in 10-40 parts by weight.

The fly ash is generated as a by-product of coal-fired power plants, cogeneration plants, paper mills, incineration plants, etc., and has an average particle size of 30 to 50 μm, a LOI (loss of ignition) of 3 to 13%, and a moisture content of less than 1%. .

These pozzolanic materials serve to lower the water content of the sludge and are not hydrophobic on their own, but the calcium hydroxide (Ca (OH) ₂ ) produced by the hydration of the inorganic binder, which will be described later, and the silicon dioxide contained in the fly ash ( SiO ₂ ) reacts to produce a hydrate. The resulting calcium silicate hydrate (Ettringitte) (3CaOAl ₂ O ₃ 3CaSO ₄ 3H ₂ O) makes the hardened structure more compact. Unburned carbon powder also has the property of adsorbing odors. The chemical formula is as follows.

3Ca (OH) ₂ + 2SiO ₂ = 3CaO · 2SiO _{2 ·} 3H ₂ O (CSH)

In particular, the soil aggregate composition presented in the present invention uses a process sludge.

The process sludge is generated as a by-product from polyester, artificial marble, and other chemical production processes, and is used in 5 to 35 parts by weight of process sludge with respect to 100 parts by weight of sludge.

The process sludge uses general wastes having a pH of 2.5 to 8.0 generated as a by-product from polyester, artificial marble, and other chemical product manufacturing processes, and adjusts to have a pH of 4 to 6.

Process sludge is an acidic substance (pH2.5 ~ pH8.0, waste process test method, 10g 25ml) generated during the recovery of the catalyst contained in the mother liquor at a polymer-based chemical product manufacturing plant such as terephthalic acid (TPA). 30min 25 ℃), generating thousands to tens of thousands of tons per year.

Process sludge used in the present invention is a general waste that is harmless to human body and hardly contains heavy metals. Until now, the process sludge has been relied on marine dumping or incineration treatment. Process sludge has a unique smell with mixed odor of organic substances contained in process sludge, specific gravity is about 1.5 and the particles are sticky, so the facility should be considered in consideration of this. It is preferable to use after deodorizing treatment using.

 Process sludge heavy metal dissolution test result Inspection items Designated Waste Standard result unit Process sludge A Process sludge B Hydrogen ion concentration (pH)  Waste acid: Less than 2.0 waste alkali: More than 12.5 2.5 to 3.5 6.5 ~ 7.5 - Hexavalent chrome     1.5 or more Not detected Not detected mg / l Lead Content     More than 3 Not detected Not detected mg / l Copper content     More than 3 0.03 Not detected mg / l Cadmium content     0.3 or more Not detected Not detected mg / l Arsenic content     1.5 or more Not detected Not detected mg / l Mercury content     0.005 or more Not detected Not detected mg / l Trichloroethylene     0.3 or more Not detected Not detected mg / l Tetrachloroethylene     0.1 or more Not detected Not detected mg / l Cyan content     1 or more Not detected Not detected mg / l Organophosphorus compounds     1 or more Not detected Not detected mg / l

Before using the process sludge, it is preferable to perform heavy metal dissolution test according to the waste process test method, and then verify that the regulated harmful element is eluted above the allowable standard value. Process sludges with very low hydrogen ion concentrations (pH) are preferably mixed with neutral process sludges or weakly alkaline materials and used preferably with a pH range of 4-6.

The process sludge of the present invention shows good results in the heavy metal dissolution test, so it can be usefully used as an alternative to acidic substances (sulfuric acid, nitric acid, hydrochloric acid) as pH regulators in acid-alkali neutralization reactions. It is easy. In addition, it is made of solid materials, so it is much easier to control the moisture content than using liquid waste acid.This eliminates the need for a separate dangerous goods storage facility and can be used without drying and grinding processes. Continuous process is possible.

In addition, the soil aggregate composition according to the present invention uses ferrous sulfate in an amount of 1 to 5 parts by weight based on 100 parts by weight of sludge in order to use it as a daily landfill for landfills.

The ferrous sulfate (FeSO ₄ ) is prepared by injecting a small amount of iron into dilute sulfuric acid and extracted from the waste solution of the steel industry, titanium oxide process, or containing a ferrous sulfate solution prepared so that the iron content is 7% or less on average It features.

In detail, the ferrous sulfate according to the present invention may contain heavy metals such as Ni, Cr, and Pb in the pickling process of a steel mill or waste sulfuric acid in a chemical industry, so it is natural to use a ferrous sulfate. Solid ferrous sulfate can use both FeSO _{4 ·} H ₂ O as monohydrate _and FeSO _{4 ·} 7H ₂ O as monohydrate _, but most ferrous sulfate monohydrates produced in Korea have strong acidity, so they It is preferable to mix and use.

It is also possible to use a ferrous sulfate solution in which iron is dissolved at 7% or less.As a result, when the ambient temperature decreases, crystalline water may be formed in the storage tank or the transfer line, which may interfere with the flow of the solution. Use care, such as processing.

This ferrous sulfate has a strong oxidation function. It easily combines with the water in the sludge to oxidize to form a solid solid and to give the final mixture a clay-like color.

In addition, an inorganic binder is used to use the soil aggregate composition according to the present invention. The inorganic binder may be one selected from the group consisting of calcium oxide, blast furnace slag powder, portland cement, and mixtures thereof.

The role of the inorganic binder serves to strengthen the binding force between the respective constituent mixtures, inhibit heavy metal elution, and enhance the uniaxial compressive strength. The main functions of these inorganic binders are as follows.

First, calcium oxide (CaO) has a much better water adsorption capacity than fly ash, activated alumina and silica gel. The calcium oxide easily reacts with moisture contained in the sludge to produce an exothermic reaction, thereby producing calcium hydroxide (Ca (OH) ₂ ), and absorbing carbon dioxide in the air to produce calcium carbonate (CaCO ₃ ). The general scheme is shown below.

CaO + H ₂ O = Ca (OH) ₂ + 15.6 Kcal / mol

Ca (OH) ₂ + CO ₂ = CaCO ₃ + H ₂ O (↑)

In addition, the blast furnace slag powder has a specific gravity of 2.85 to 2.95, which is about 8% lower than cement, but has excellent dispersibility in concrete. When stimulated with alkali (Ca (OH) ₂ , KOH, NaOH) or sulfates (CaSO ₄ ), it has latent hydraulic properties that begin to cure as the elution of ions from the slag and insoluble matters precipitate. These materials can be mixed with the Portland cement alone to achieve superior quality, such as enhanced long-term strength, reduced heat of hydration, and increased watertightness.

Portland cement is a material that meets moisture in the sludge, loses fluidity, hardens, solidifies and hardens to develop strength. The main components of the Portland cement include lime CaO, silica SiO ₂ , alumina Al ₂ O ₃ and iron oxide Fe ₂ O ₃ , and these components generate heat of hydration when hydrated. The heat of hydration is the largest tricalcium aluminate, followed by tricalcium silicate. And among the constituents of cement, tricalcium silicate is fast in hydration and good in strength, contributing to early strength. In addition, silicate lime is slow in hydration and enhances strength over a long period of time. And alumina tricalcite is faster to hydrate than other constituent compounds, and reacts rapidly with water to harden. At this time, the hydration reaction is known to proceed as follows.

3CaO3Al ₂ O ₃ CaSO ₄ + 8CaSO ₄ + 6Ca (OH) ₂ + 90H ₂ O = 3 (CaOAl ₂ O ₃ CaSO ₄ 32H ₂ O) ₂

Ett0ringitte

3Ca (OH) ₂ + 2SiO ₂ = 3CaO · 2SiO _{2 ·} 3H ₂ O (CSH-based hydrate)

The inorganic binder uses 10 to 25 parts by weight of one selected from the group consisting of calcium oxide, blast furnace slag fine powder, portland cement, and mixtures thereof, based on 100 parts by weight of sludge. If the amount of the inorganic binder is less than the above range, the binding force between particles is weakened, which is not sufficient. On the contrary, if the amount of the inorganic binder exceeds the above range, the ratio of solidification performance to the increase in processing cost is low, and the concentration of hydrogen ions in the final mixture is increased. This is because the ammonia gas is dissociated from the ions and there is enough potential to generate harmful gas. When used in combination with sewage sludge and other inorganic minerals, the content of the inorganic binder may be increased to 15 to 25 parts by weight based on 100 parts by weight of the sludge.

The soil aggregate composition according to the present invention comprising the composition as described above includes purified water and sewage sludge and pozzolanic, fly ash, process sludge, ferrous sulfate and an inorganic binder. The soil aggregate composition is selected and stored only in the final processed material containing a lot of mineral minerals, and then dried to be used as a raw material for filling aggregates, building blocks, sidewalk blocks, light bricks, lightweight bricks, clay bricks as building materials. At this time, the composition of the bar can be appropriately adjusted according to each purpose.

Manufacturing method

Hereinafter, a method for preparing the soil aggregate composition of the present invention with reference to the accompanying drawings. 1 is a flowchart showing a method for producing soil aggregate using purified water and sewage sludge according to the present invention, and FIG. 2 is a view listing the names of mixed additives used for producing soil aggregate using purified water and sewage sludge according to the present invention. .

Referring to Figure 1, the soil aggregate is produced using a process sludge and sludge

(S1) 20 to 50 parts by weight of a pozzolanic substance (Reject Ash) of coarse powder having a specific surface area of 2,000 cm ² / g or less and 10 to 40 parts by weight of fly ash having a specific surface area of 3,000 to 3,500 cm ² / g. A first mixing step of preparing a first mixture;

(S2) a second mixing step of preparing a second mixture by mixing 5 to 35 parts by weight of process sludge and 1 to 5 parts by weight of ferrous sulfate, which are produced as by-products in polyester, artificial marble, and other chemical product manufacturing processes;

(S3) 3 to prepare a third mixture by mixing the first mixture and the second mixture with 10 to 25 parts by weight of one inorganic binder selected from the group consisting of calcium oxide, blast furnace slag fine powder, portland cement, and mixtures thereof. Tea mixing step;

(S4) a fourth mixing step of preparing a fourth mixture by mixing the third mixture with 100 parts by weight of sludge; And

(S5) It is prepared through a curing step of curing the fourth mixture.

First, in the step (S1), a first mixing step of preparing a first mixture is performed by mixing 20 to 50 parts by weight of coarse pozzolanic material (Reject Ash, residue) and 10 to 40 parts by weight of fly ash.

Next, in the step (S2), a second mixing step of preparing a second mixture is performed by mixing 5 to 35 parts by weight of process sludge and 1 to 5 parts by weight of ferrous sulfate.

Next, in step (S3), a third mixing step of preparing a third mixture is performed by mixing the first mixture and the second mixture with 10 to 25 parts by weight of the inorganic binder.

Next, in step (S4), the fourth mixture is mixed with 100 parts by weight of the sludge to prepare a fourth mixture.

Mixers used in the mixing of the (S1) to (S4) may be a device that is commonly used, for example, double cone mixer, ribbon mixer, V mixer, paddle mixer, blade mixer, high speed stirring mixer, drum mixer, and the like. Use

Next, in step (S5) to prepare the soil aggregate through the curing step of curing the fourth mixture.

The fourth mixture is fed to a curing storage facility via a belt conveyor. At this stage, insoluble hydrates are stabilized to fix heavy metals to inhibit elution, and during the hydration of poorly soluble materials such as Ca ₆ Al ₂ (OH) ₂ (SO ₄ ) · 26H ₂ O or CaPb ₃ Si ₃ O ₁₁ Heavy metals are substituted or solidified into the crystal structure to stabilize.

The final mixture thus formed becomes more robust as the residual moisture evaporates in the curing storage facility. Depending on the application, it is usually cured for one day or 1-3 days and then recycled.

In particular, when water sludge alone is treated alone, the water content of the final mixture is very low, and when it is worried about scattering, it can be reused as a water content control agent for curing or sewage sludge after curing.

Usage

The soil aggregate produced through the steps described above has a water content of 40 vol% or less, an organic matter of about 5 to 30 vol%, and a uniaxial compressive strength of 1.0 to 1.7 kg / cm ² . As a result, the soil aggregate composition not only satisfies the uniaxial compressive strength 0.5kg / cm ² for use as cover material, but also exceeds the 1.0kg / cm ² of the filling material for landfill.

Therefore, the final mixture completed in the above step can be recycled as soil cover for cover, fill, ground reinforcement and land improvement, as well as raw materials for building materials. In order to use it as a safer raw material for building materials, only the final processed materials containing mineral minerals are separately selected and stored, and then dried and used as filling materials for fine aggregates, sidewalk blocks, raft blocks, lightweight bricks, clay bricks, etc. It is preferable.

In particular, in the present invention, it is more efficient to treat the mixed sludge and the sewage sludge than to treat the sewage sludge alone, which accounts for 30 to 60% of the silica components in the purified sludge composition to be compressed in the sewage sludge and compressed in the stirring process. The sewage sludge containing moisture is dispersed. This facilitates moisture absorption, thereby promoting exothermic reactions, ion exchange reactions, pozzolanic reactions, carbonation reactions, and hydration reactions of the pozzolanic material and the inorganic binder, thereby increasing the pozzolanic reaction and allowing the solidification to proceed rapidly. As a result, drying proceeds rapidly and water content is significantly reduced and heavy metals are removed to shorten curing time.

In addition, purified sludge, especially Alum sludge, improves treatment efficiency and sludge improvement during wastewater treatment, and is excellent in adsorption and removal of phosphorus. In other words, when alum sludge is directly injected during wastewater treatment, up to 95% of phosphorus in wastewater is removed and iron salt sludge is injected at a concentration of 1,100 mg / L at pH 6, resulting in highly efficient removal of oil, grease, COD and TSS. Found to be excellent. Water purification sludge can be effectively used to remove the chromaticity of textile wastewater and wastewater containing various dyes.

As a result of using alum sludge as a condensation nucleus during the flocculation process, it is possible to remove up to 94% of lead in the waste water by injecting 75-100mg / L.

Purified sludge is also used to adsorb and remove various contaminants and heavy metals, especially chromium and mercury, from wastewater. Phosphate in the wastewater is adsorbed through the precipitation reaction with aluminum ions by substituting functional groups on the surface of the alum sludge. The maximum chromium adsorption capacity of the purified sludge was 1.4 mg / g at pH4.6 and mercury was 0.43 mg / g at pH6.0. In addition, fluorine, copper, and lead can also be adsorbed by purified sludge.

In Korea, about 160 tons of purified sludge was produced per day in 2005, and about 130 tons were treated by ocean dumping method (National Institute of Environmental Research, 2006). Increasing the input of purified sludge into sewage sludge increases the removal of heavy metals and the solidification capacity proportionately. In particular, when solidifying the purified sludge alone, treatment efficiency is superior to the same treatment weight compared to sewage sludge.

At the same time, the present invention replaces the strong acid stock and liquid waste acid with pH control function with solid process sludge, which is the waste of the workplace, maximizing the treatment cost and maximizing the treatment efficiency, blocking the generation of harmful gases, and eliminating the drying and grinding process. In addition to simplifying the process, waste resources can be recycled.

Although specific embodiments of the present invention have been described and illustrated above, it is obvious that the present invention may be embodied in various modifications by those skilled in the art. Such modified embodiments should not be individually understood from the technical spirit or the prospect of the present invention, and such modified embodiments should fall within the scope of the appended claims.

(Examples 1-3)

A first mixture is prepared by mixing pozzolanic (specific surface area of 2,000 cm ² / g or less) and fly ash (specific surface area of 3,000 to 3,500 cm ² / g), and mixing the process sludge with ferrous sulfate in a separate mixer. Two mixtures were prepared.

The first mixture, the second mixture, and an inorganic binder were added to the high speed stirring mixer to obtain a third mixture, and then, purified water sludge was added and uniformly mixed again at a stirring speed of 10 to 12 RPM to prepare an earth aggregate composition.

Each composition used at this time is as shown in Table 2.

Composition (part by weight) Example 1 Example 2 Example 3 First mixture Pozzolan substance (residue) 20 20 20 Fly ash 10 10 10 Second mixture Process sludge 15 25 35 Ferrous sulfate 3 3 3 Tertiary mixture bookbinder Calcium oxide 5 - - Blast furnace slag powder - - 3 Portland cement 5 10 7 Fourth mixture Water purification and sewage sludge (1: 1) 100 100 100

Experimental Example 1

The physical properties of the soil aggregate composition prepared in the above example were measured, and the results obtained are shown in Table 3 below. At this time, sewage sludge was used as Comparative Example 1.

Water content (moisture) test

According to the waste process test method, the final mixture sample in the wet state was dried at 105 to 110 ° C. and the moisture content was measured by the weight difference before and after drying.

Organic matter content test

According to the waste process test method, add 25% ammonium nitrate solution to 20 g of the first dried sample, wet the sample slowly, and carbonize it by heating slowly. Heat it for 3 hours in an electric furnace at 600 ㅁ 25 ℃, cool it in sulfate desiccator, and weigh it. (W3) was calculated by precise measurement.

Uniaxial compressive strength test

Samples were made of cylindrical specimens and tested by applying a axial load (1% / min) with a compressive strength tester in the absence of lateral pressure.

Ammonia Gas (NH ₃ ) exam

An average value was obtained by measuring three times directly on the surface of the sample using a detection tube type gas detector (Gastec).

division Moisture content (%) Organic matter content (%) Uniaxial Compressive Strength (kg / cm ² ) NH ₃ generation amount (ppm) Example 1 37 22.3 1.28 12 Example 2 39 24.1 1.62 5 Example 3 37 27.6 1.54 0 Comparative Example 1 79 48.6 0.31 35

Referring to Table 3, the soil aggregate composition prepared according to the present invention can be seen that the water content (lowest 37%) and organic matter content (less than 30%) is significantly lower than the sewage sludge. In addition, the uniaxial compressive strength was measured as 1.0kg / cm ² or more, the maximum 1.62 kg / cm ² , it can be seen that the amount of ammonia gas is reduced as the process sludge addition amount is increased. It can be seen that this value is sufficiently controllable by adjusting the content of the composition used.

1 is a flow chart showing a method for producing soil aggregate using water and sewage sludge according to the present invention.

      Figure 2 is a view showing the name of the mixed additives used in the soil aggregate manufacturing method using purified water and sewage sludge according to the present invention.

Claims (10)

delete In the earth aggregate composition for civil engineering and building materials using process sludge and sludge, About 100 parts by weight of sludge 20 to 50 parts by weight of a pozzolanic substance (Reject Ash, residue) having a specific surface area of 2,000 cm ² / g or less, 10 to 40 parts by weight of fly ash having a specific surface area of 3,000 to 3,500 cm ² / g, 5 to 35 parts by weight of process sludge produced as a by-product from polyester, artificial marble and other chemical products 1 to 5 parts by weight of ferrous sulfate, and 10-25 parts by weight of one inorganic binder selected from the group consisting of calcium oxide, blast furnace slag powder, portland cement and mixtures thereof Including; The sludge is purified sludge, sewage sludge or mixed sludge thereof, When using purified water and sewage sludge alone, 100 parts by weight is used, and in the case of mixed use, process sludge and sludge civil engineering using 10 to 90 parts by weight, and sewage sludge to 10 to 90 parts by weight. Earth aggregate composition for construction materials. The method of claim 2, The sludge is collected from feldspar, pyrophillite, silica stone, pottery stone, pottery stone, and sericite mines. Waste stone powder generated as a by-product in the process, the process of manufacturing aluminum hydroxide Red Mud, and a combination of these inorganic minerals selected from the group consisting of a process sludge and sludge for civil engineering and building materials Earth aggregate composition. The method of claim 3, The sludge is a mixture of 50 to 85% by weight of purified sludge and 15 to 50% by weight of inorganic minerals; A mixture of 50 to 85% by weight of sewage sludge and 15 to 50% by weight of inorganic minerals; And Soil aggregate composition for civil engineering and building materials using process sludge and sludge, characterized in that any one of a mixture of water purification sludge 30-50% by weight, sewage sludge 30-35% by weight and inorganic minerals 15-40% by weight . The method of claim 2, The fly ash is generated as a by-product of coal-fired power plants and cogeneration plants, paper mills, or incineration plants, and has an average particle size of 30 to 50 µm, a LOI (loss of ignition) of 3 to 13%, and a moisture content of less than 1%. Soil aggregate composition for civil engineering and building materials using the process sludge and sludge. delete delete The method of claim 2, The soil aggregate composition is a soil aggregate composition for civil engineering and building materials using a process sludge and sludge, characterized in that it is used as a filling material of fine aggregate, sidewalk block, raft block, lightweight brick, or clay brick of building materials. The method of claim 2, The soil aggregate composition and water content of 40 vol% or less, and the organic matter is from 5 to 30 vol%, the unconfined compressive strength of 1.0~1.7 kg / cm ² in the sludge process, characterized in using a sludge and civil engineering and building materials for soil Aggregate composition. In the manufacturing method of earth aggregate composition for civil engineering and building materials using process sludge and sludge, (S1) 20 to 50 parts by weight of a pozzolanic substance (Reject Ash) of coarse powder having a specific surface area of 2,000 cm ² / g or less and 10 to 40 parts by weight of fly ash having a specific surface area of 3,000 to 3,500 cm ² / g. A first mixing step of preparing a first mixture; (S2) a second mixing step of preparing a second mixture by mixing 5 to 35 parts by weight of process sludge and 1 to 5 parts by weight of ferrous sulfate, which are produced as by-products in polyester, artificial marble, and other chemical product manufacturing processes; (S3) 3 to prepare a third mixture by mixing the first mixture and the second mixture with 10 to 25 parts by weight of one inorganic binder selected from the group consisting of calcium oxide, blast furnace slag fine powder, portland cement, and mixtures thereof. Tea mixing step; (S4) a fourth mixing step of preparing a fourth mixture by mixing the third mixture with 100 parts by weight of sludge; And (S5) curing step of curing the fourth mixture Process for producing earth aggregate composition for civil engineering and building materials using a process sludge and sludge, characterized in that it is produced.

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