KR101185428B1 - Sludge solidified agent and menufacturing method of artificial soil usign the same - Google Patents

Abstract

PURPOSE: An agent for solidifying organic sludge is provided to reduce content of water content by using CaO which is contained in raw material in quantity, to evaporate moisture through absorption and heat generation of CaO, thereby capable of preventing generation of bad smell and elution of heavy metal. CONSTITUTION: An agent for solidifying organic sludge comprises 100.0 parts by weight of paper sludge incineration ash of which calcium oxide(CaO) content is 35-70 %, 10-50 parts by weight of high-calcium fly ash, of which CaO content is 40-75%, generated from an in-furnace desulfurization type coal boiler, and 10-200 parts by weight of high-calcium slag dusts of which CaO content is 40-80 %. Surface area of the paper sludge incineration ash, high-calcium fly ash, and high-calcium slag dust is respectively 2,000-9,000 /g.

Description

Organic sludge hardener and method for manufacturing artificial soil using same {SLUDGE SOLIDIFIED AGENT AND MENUFACTURING METHOD OF ARTIFICIAL SOIL USIGN THE SAME}

The present invention relates to a solidifying agent for effectively solidifying organic sludge, such as sewage sludge, and an artificial soil manufacturing method using the same. More specifically, high calcium fly ash generated from a paper sludge incineration ash, a furnace desulfurization type coal combustion boiler, and the like, By using absorption of CaO contained in high calcium slag dust, heat generation and volume expansion action, artificial soil is produced by reducing the moisture content of high functional sludge such as sewage sludge. The present invention relates to an organic sludge solidifying agent that fundamentally blocks the generation of odors such as ammonia odors and an artificial soil manufacturing method using the same.

Recently, a large amount of organic sludge is generated. For example, sewage sludge is an organic sludge composed of carcasses such as microorganisms remaining after purification of domestic sewage at a sewage treatment plant. As a representative high functional material, it has been conventionally treated by methods such as ocean dumping, landfilling and the like.

For example, sewage sludge, which is currently emitting more than 8,000 tons per day, has been banned from landfills since July 2003, and even the most easily disposed of dumping at sea is limited only by the end of 2011 under the London Convention. have.

Currently, the sewage sludge is solidified in Daegu, Busan, and Jeju, including landfills in the Seoul metropolitan area, and a treatment facility is being manufactured to produce artificial soils that can be used as daily and intermediate cover materials. However, there is an urgent need to develop an excellent hardener in terms of facility operability and quality of artificial soil.

Conventional researches on sewage sludge solidifying agents have not only caused the problems of facility mobility, such as sticking to facilities due to the use of strong alkaline materials such as quicklime and cement, and the quality problems such as odor generation and reslurrying. In order to reduce the emission of ammonia by adding additional acidic materials such as expensive sulfuric acid and iron sulfate, the cost of raw materials is high and the economical efficiency is insufficient.

The present invention has been made to solve the above problems, an object of the present invention is to use a high function such as organic sludge by the absorption, exothermic and volume expansion of CaO contained in a large amount of paper sludge, high calcium fly ash and high calcium slag dust Artificial sludge is produced by reducing the water content of sludge, and organic sludge solidifying agent which fundamentally blocks the generation of odors such as ammonia odor due to high alkali by mixing acidic material with the manufactured artificial soil and artificial soil manufacturing method using the same In providing.

In order to solve the above technical problem, the organic sludge solidifying agent according to the present invention is produced in a furnace desulfurization type coal combustion boiler with respect to 100 parts by weight of paper sludge incinerator having a calcium oxide (CaO) content of 35 to 70%, and calcium oxide content. 10 to 50 parts by weight of the high calcium fly ash (40 to 75%) and 10 to 200 parts by weight of the high calcium slag dust having a calcium oxide (CaO) content of 40 to 80%.

In addition, the paper sludge incineration material, high calcium fly ash and high calcium slag dust is preferably a specific surface area of 2,000 ~ 9,000 / g.

In addition, it is preferable to further include a heating agent in order to increase the exothermic reaction with the organic sludge.

In addition, the heating agent is preferably any one or a mixture of two or more selected from the group consisting of quicklime powder, light dolomite powder and petroleum coke incinerator powder.

In addition, the heat generating agent is preferably mixed 5 to 50 parts by weight based on 100 parts by weight of the papermaking sludge incinerator.

In addition, it is preferable to further include a pH reducing agent to prevent odor generation and heavy metal elution of the solidified solidified organic sludge.

In addition, the pH reducing agent is any one or a mixture of two or more selected from the group consisting of acid powder suitable for sulfuric acid powder, sodium aluminum sulfate (SAS) powder and sodium aluminum fluoride (SAF) powder by-products generated during the polysilicon manufacturing process. It is preferable.

In addition, the pH reducing agent is preferably mixed 5 to 50 parts by weight based on 100 parts by weight of the papermaking sludge incineration ash.

Artificial soil manufacturing method according to the present invention comprises the steps of 1) preparing the hardener; 2) measuring 5 to 80 parts by weight of the solidifying agent based on 100 parts by weight of organic sludge; 3) mixing the metered organic sludge with a solidifying agent; And 4) curing the mixture of organic sludge and solidifying agent.

In addition, when the pH reducing agent is not included in the solidifying agent, it is preferable that after step 4), 5) adding and mixing the pH reducing agent to the mixture is further added.

In addition, the pH reducing agent is preferably added to 10 to 100 parts by weight based on 100 parts by weight of the papermaking sludge incineration ash.

According to the present invention, there is an effect of reducing the water content of organic sludge by using CaO contained in a large amount of high calcium fly ash and high calcium slag dust generated from paper sludge incineration residue and furnace desulfurization type coal combustion boiler.

It also has the effect of evaporation of water due to the absorption of CaO and the exothermic action.

In particular, the high-calcium slag dust contains a large amount of Free-CaO and FeO, which is very exothermic and has a high exothermic temperature.

In addition, in the preparation of a solidifying agent of the pH reducing agent, it is also effective to prevent the occurrence of odor and the elution of heavy metals by reducing the pH of the solidified by post-injection or post-addition to the mixture.

1 is a diagram illustrating a process of generating high calcium fly ash in a coal-fired boiler which does in-furnace desulfurization without providing a separate desulfurization facility.
Figure 2 illustrates a process for generating fly ash in a coal-fired power plant equipped with a separate desulfurization facility.

Hereinafter, the organic sludge solidifying agent according to the present invention and a manufacturing method of artificial soil using the same will be described in detail.

First, the components and actions of the organic sludge solidifying agent according to the present invention will be described.

The organic sludge solidifying agent according to the present invention is a paper sludge incinerator having a calcium oxide (CaO) content of 35% to 70%, a high calcium fly ash having a calcium oxide content of 40 to 75%, and a calcium oxide (CaO) content of 40 to Contains 80% high calcium slag dust. The high calcium fly ash is preferably used that is generated in the furnace desulfurization coal combustion boiler.

Calcium oxide contained in high calcium fly ash and high calcium slag dust produced in paper sludge incineration ash and furnace desulfurization coal combustion boiler is absorbed, exothermic and expanded with water to become calcium hydroxide. The reaction scheme is as follows.

CaO + H ₂ O-> Ca (OH) ₂ +15.6 mol ^-1

Although fly ash generated from a coal-fired boiler is recycled to concrete admixtures, fly ash containing a large amount of calcium oxide cannot be used as concrete admixtures due to its absorption, heat generation, and expansion characteristics. In (KS), the coal-fired fly ash standard with high calcium oxide content is not established.

In addition, the paper sludge incineration material uses limestone fine powder as a filler to reduce the amount of pulp used in the paper manufacturing process and to improve the quality of the paper. The limestone fine powder discharged in the form of sludge is incinerated in a boiler. Incinerator having a high content of the decarbonated calcium oxide is generated.

In particular, the high calcium slag dust is subjected to particle size adjustment in order to utilize slag generated as a by-product in the production of steel and non-ferrous metals as a road substrate material, wherein the main components are CaO component and FeO as the fine dust collected in the dust collector during the grinding process It contains a large amount of components, and it is not available to be used as a concrete admixture due to its absorption, heat generation, and expansion characteristics.

Therefore, the present invention uses high-calcium fly ash and high-calcium slag dust generated from the paper sludge incinerator and the furnace desulfurization-type coal-fired boiler that are not available as concrete admixtures.

In other words, when high-water content organic sludge is mixed with paper sludge incinerator containing a large amount of calcium oxide, and high calcium fly ash and high calcium slag dust generated in a furnace desulfurization coal-fired boiler, calcium hydroxide is produced by the above reaction and water of organic sludge is produced. This is to be reduced. In addition, since the heat generated by the above reaction evaporates the water of the organic sludge, it is possible to further reduce the moisture content of the organic sludge.

Particularly, high calcium slag dust has a high exothermic temperature and absorption ability when contacted with moisture by free-CaO and FeO components, which are much higher than high calcium fly ash, thus reducing the amount of quicklime and light dolomite used as a heating agent. have.

The specific surface area of the high calcium fly ash and the high calcium slag dust generated in the papermaking sludge ash and the furnace desulfurization type coal combustion boiler is preferably 2,000 to 9,000 / g. If the specific surface area is less than 2,000 / g, there is a lack of fine powder and the activity is lowered. Therefore, the water content reduction effect is lowered when the organic sludge is solidified. If the specific surface area is more than 9,000 / g, the apparent density is lowered during the transfer of the solidifying agent. It scatters and facility operability falls.

Fly ash is produced in a coal-fired power plant, and in particular, the fly ash produced in a power plant having a furnace desulfurization method has a high content of calcium oxide. In the furnace desulfurization method, because the mixed combustion of coal and limestone, the fly ash contains a large amount of free CaO. Figure 1 is a schematic diagram showing a high calcium fly ash generating process of the furnace desulfurization coal fired boiler.

In contrast, fly ash produced in power plants with separate desulfurization plants has less than 5% calcium oxide. 2 is a schematic diagram showing a fly ash generating process of a coal-fired power plant equipped with a separate desulfurization facility.

Table 1 shows the difference between the power plant fly ash with separate wet desulfurization and the high calcium fly ash in the furnace.

Item Power plant with separate desulfurization Fly ash Furnace Desulfurization Method  power plant High calcium Fly ash Combustion fuel Coal Coal, limestone, other chemicals Combustion temperature 1350 degrees
-High combustion efficiency for economic power plant operation, reduction of coal ash generation rate and high quality coal ash discharge About 850 degrees
-Nitrogen emission reduction while decarbonation temperature range Exhaust Gas Desulfurization Facility Separate wet desulfurization facility Induction of furnace desulfurization with limestone mixture Exhaust gas denitrification plant Separate denitrification equipment Maintain low combustion temperatures and spray ammonia and other chemicals into boilers Chemical composition SiO _{2 ,} Al ₂ O _{3 ,} Fe ₂ O ₃ Due to limestone mixing
High free CaO component. Vitrification Degree high low Main recycling purpose Peak season with concrete admixture
Recycle all generation Clay substitute cement raw material,
Landfill of waste disposal site through long distance transportation Advantages and problems of using concrete admixture -Increased long-term strength with pozzolanic activity
- Improved workability
-Reduced unit quantity (durability, improved strength)
-Reduced heat of hydration (structure crack prevention) -Free CaO exothermic reaction
-Unit quantity increase (strength, durability decline)
-Increased heat of hydration (structure cracking)
-Reduced workability Etc KS L 5405 conformity product generation Do not satisfy the chemical composition and physical performance of KS L 5405

That is, the fly ash produced by the furnace desulfurization method contains a large amount of calcium oxide, but the fly ash produced in a facility equipped with a separate desulfurization device contains a very small amount of calcium oxide. Therefore, as described above, fly ash generated in a facility having a separate desulfurization device contains a small amount of calcium oxide can be recycled as a concrete admixture.

Therefore, the solidifying agent of the present invention uses high-calcium fly ash and high-calcium slag dust generated from paper sludge incinerator and non-reactor desulfurization coal-fired boilers as concrete admixtures as main raw materials.

The mixing ratio of the high calcium fly ash generated in the paper sludge incinerator and the furnace desulfurization coal combustion boiler is preferably 10 to 50 parts by weight of the high calcium fly ash generated in the furnace desulfurization coal combustion boiler, based on 100 parts by weight of the paper sludge incinerator. If the amount of high calcium fly ash generated in the desulfurization type coal-fired boiler is less than 10 parts by weight, the exothermic performance is lowered. If it is more than 50 parts by weight, the mixture of the organic sludge and the hardener is kneaded and the equipment mobility is reduced. .

In addition, the mixing ratio of the papermaking sludge incineration material and high calcium slag dust is preferably 10 to 200 parts by weight of high calcium slag dust with respect to 100 parts by weight of papermaking sludge incineration ash, and the heat generation performance is lowered when the mixing amount of the high calcium slag dust is less than 10 parts by weight. When it is more than 200 parts by weight, the mixture of organic sludge and solidifying agent is kneaded and the equipment mobility is lowered.

In addition, the solidifying agent according to the present invention further includes a heat generating agent when organic sludge has a high moisture content due to seasonal factors or requires more heat for other reasons. The heat generating agent includes quicklime powder, light dolomite powder, and petroleum coke incineration powder. It is preferably any one selected from the group consisting of or a mixture of two or more.

The quicklime powder is a product obtained by calcining limestone at a high temperature, decarbonated, and then processed into a powder having a constant particle size, which is generally obtained on the market, and has a CaO content of 85% or more.

The light dolomite powder is a product obtained by calcining dolomite at high temperature and then decarbonated into a powder having a constant particle size, which is generally obtained on the market, and has a CaO + MgO content of 80% or more.

The petroleum coke ash is a raw material used in place of coal when high calorie and combustion efficiency is required. This also mixes limestone for desulfurization, and decarbonated calcium oxide particles occupy most of the ash. , Exothermic and volume expansion.

The heat generating agent is preferably mixed 5 to 50 parts by weight based on 100 parts by weight of the papermaking sludge incinerator. If the amount of the heat generating agent is less than 5 parts by weight, the heat generation when reacting with the sludge is insufficient, and the water content reduction effect is lowered. When the amount of the heat generating agent is more than 50 parts by weight, the water content is greatly reduced, but the strength is increased so much that the solids are firmly fixed to the equipment. There is a risk of lowering the productivity.

In addition, the solidifying agent according to the present invention is an acid component suitable for the powder of sulfuric acid such as neutral fly ash, metakaolin, etc. in order to prevent odor from being generated in the artificial soil which is a solid of organic sludge, and SAS which is a by-product generated during the polysilicon manufacturing process. PH reducing agents such as (Sodium Aluminum Sulfate) powder and Sodium Aluminum Fluorid (SAF) powder may be further incorporated. When the pH reducing agent is further mixed, the pH of the organic sludge solidified drops quickly, and the pH of the solidified is adjusted to 12 or less, which is the pH boundary that generates the most odor.

The mixing amount of the pH reducing agent is mixed with 5 to 50 parts by weight based on 100 parts by weight of the papermaking sludge incinerator when prepared by pre-injection into a solidifying agent. If the amount of the pH reducing agent is less than 5 parts by weight based on 100 parts by weight of the papermaking sludge incinerator, there is no pH reduction effect. When the amount of the pH reducing agent is more than 50 parts by weight, the economical efficiency is reduced and the solids become tough.

In addition, when the pH reducing agent is post-added to the organic sludge solidified, 10 to 100 parts by weight with respect to 100 parts by weight of the paper sludge incineration ash is added and mixed. If the amount of the pH reducing agent is less than 10 parts by weight based on 100 parts by weight of the papermaking sludge incinerator, there is no pH reduction effect. If the amount of the pH reducing agent exceeds 100 parts by weight, the economical efficiency is lowered and the solidity of the solids is increased.

Hereinafter will be described the artificial soil manufacturing method according to the present invention.

First, the above-mentioned solidifying agent is prepared, and then 5 to 80 parts by weight of the solidifying agent is uniformly mixed with respect to 100 parts by weight of sewage sludge. If the content of the solidifying agent is mixed at less than 5 parts by weight, the water content is not sufficiently reduced, so that it cannot be used as a cover material. If the content is more than 80 parts by weight, the water content is too low, the solids are scattered, the cover work is difficult, and the economic efficiency is reduced.

Next, the mixture of the sewage sludge and the hardener is cured at room temperature or heated until the moisture content is 60% or less.

Finally, if necessary, the mixture is post-added with a pH reducing agent.

Hereinafter, the performance of the embodiment of the artificial soil prepared using the solidifying agent according to the present invention and the comparative example for comparing the properties with the above example were analyzed.

Example  One

First, with respect to 100 parts by weight of the papermaking sludge incinerator having a calcium oxide content of 47%, 20 parts by weight of a high calcium fly ash having a 54% calcium oxide content generated in the furnace desulfurization coal fired boiler and a furnace desulfurization coal fired boiler. 10 parts by weight of high calcium fly ash with 49% calcium oxide content, 50 parts by weight of high calcium slag dust with 57% CaO content, and 15 parts by weight of sodium aluminum sulfate (SAS) powder as a pH reducing agent Was prepared.

Next, with respect to 100 parts by weight of sewage sludge having a water content of 81%, 50 parts by weight of the solidifying agent prepared as described above was mixed to cure at room temperature to prepare artificial soil.

Example  2

First, with respect to 100 parts by weight of the papermaking sludge incinerator having a calcium oxide content of 47%, 20 parts by weight of a high calcium fly ash having a 54% calcium oxide content generated in the furnace desulfurization coal fired boiler and a furnace desulfurization coal fired boiler. 10 parts by weight of high calcium fly ash with 49% calcium oxide content, 50 parts by weight of high calcium slag dust with 57% CaO content, 20 parts by weight of a mixture of 60% by weight of light and small dolomite powder and 40% by weight of quicklime powder as a heating agent And, as a pH reducing agent, 15 parts by weight of SAS (Sodium Aluminum Sulfate) powder was mixed uniformly to prepare a solidifying agent.

Next, with respect to 100 parts by weight of sewage sludge having a water content of 81%, 50 parts by weight of the solidifying agent prepared as described above was mixed to cure at room temperature to prepare artificial soil.

Comparative example  One

First, with respect to 100 parts by weight of the papermaking sludge incinerator having a calcium oxide content of 47%, 20 parts by weight of a high calcium fly ash having a 54% calcium oxide content generated in the furnace desulfurization coal fired boiler and a furnace desulfurization coal fired boiler. 10 parts by weight of high calcium fly ash having a calcium oxide content of 49% and 15 parts by weight of sodium aluminum sulfate (SAS) powder as a pH reducing agent were uniformly mixed to prepare a solidifying agent.

Next, with respect to 100 parts by weight of sewage sludge having a water content of 81%, 50 parts by weight of the solidifying agent prepared as described above was mixed to cure at room temperature to prepare artificial soil.

Comparative example  2

First, with respect to 100 parts by weight of the papermaking sludge incinerator having a calcium oxide content of 47%, 20 parts by weight of a high calcium fly ash having a 54% calcium oxide content generated in the furnace desulfurization coal fired boiler and a furnace desulfurization coal fired boiler. 10 parts by weight of a high calcium fly ash having a calcium oxide content of 49%, 20 parts by weight of a mixture of 60% by weight of a light dolomite powder and 40% by weight of quicklime powder as a heating agent, and a sodium aluminum sulfate (SAS) powder as a pH reducing agent 15 The weight part was uniformly mixed to prepare a solidifying agent.

Next, with respect to 100 parts by weight of sewage sludge having a water content of 81%, 50 parts by weight of the solidifying agent prepared as described above was mixed to cure at room temperature to prepare artificial soil.

Performance Test Method and Result of Artificial Soil

As shown in Table 2 below, the water content was measured by the KS F 2306 method, and the compressive strength and permeability tests were performed by the KS F 2343 and KS F 2322 methods.

Experiment Way Remarks Water content KS F 2306 How to measure the water content of soil Compressive strength KS F 2343 Uniaxial compressive strength method Permeability coefficient KS F 2322 Variable Position Permeability Test

(1) water content change

The moisture content of artificial soils prepared by Example 1 and Comparative Example 1 according to time is shown in Table 3 below. As confirmed in Table 3, the water content of the sewage sludge before mixing the solidifying agent was 81%, it can be seen that the water content is rapidly reduced over time. The moisture content is greatly reduced because, as described above, the exothermic reaction occurs immediately after the solidifying agent is mixed with the sewage sludge and the hydration reaction proceeds simultaneously. In addition, the water content gradually decreases due to hydrate formation and natural drying over time. After 3 days of natural curing, it is expected to not only be easy to handle but also to increase the compressive strength.

In particular, Example 1 exhibited a water content reduction effect almost similar to that of Comparative Example 2, even though no exothermic agent was added. As described above, it is possible to reduce the water content of the sludge more sharply than the comparative example because the high calcium slag dust is included. That is, by contacting with water by the free-CaO and FeO components contained in a large amount of high calcium slag dust, the exothermic temperature is higher than the high calcium fly ash, and the water absorption ability is superior, so that the water content of the sludge is drastically reduced. Therefore, according to the present invention, it is possible to reduce the amount of heat generating agent such as quicklime in order to exhibit the same water content reducing effect as compared with the comparative example.

division Immediately after improvement 3 hours 1 day 3 days Example 1 46.3% 44.3% 36.8% 32.6% Example 2 45.3% 36.5% 33.6% 27.6% Comparative Example 1 50.7% 49.3% 40.6% 35.6% Comparative Example 2 45.9% 43.6% 35.8 31.9%

(2) change in uniaxial compressive strength

Table 4 below shows the uniaxial compressive strength of the artificial soil prepared by Example 1. As can be seen through the 3 days of curing, Example 1 was 4.2kgf / cm ² , Comparative Example 1 was found to be 3.9kgf / cm ² .

This is 0.5kgf / cm ² , the strength standard of cover and fill material. And 1.0 kgf / cm ² , which is significantly higher than that, and exhibited sufficient strength to be used as various ground materials such as soft ground improving material, water repellent material, and back fill material. When mixed with a solidifying agent, it can reduce moisture and reform sewage sludge by absorbing exothermic reaction, which leads to consolidation of particles, resulting in consolidation promoting effect, and calcium silicate reaction is induced by CaO and fly ash SiO ₂ components. This is because the solidification reaction to secure the strength occurs to enhance the strength. In addition, the water content of sewage sludge is relatively lowered due to the absorbency of the solidifying agent, and the fine clay and colloidal components are separated by the absorbent of the solidifying agent and ion exchange, pozzolanication and carbonation reaction, and the particle size distribution is changed to improve the quality soil. It is judged that uniaxial compressive strength increases.

In particular, unlike the comparative example, the embodiment further includes high calcium slag dust, so that the water saving and the reforming effect of the sludge by the absorption exothermic reaction are further increased. As the acidic film is destroyed by the stimulus, latent hydrophobicity is activated to increase the solidification strength.

division Compressive strength ( kgf /) 1 day Compressive strength ( kgf /) 3 days Example 1 2.3 4.2 Example 2 2.9 5.2 Comparative Example 1 1.9 3.9 Comparative Example 2 2.5 4.5

(3) change in uniaxial compressive strength before and after immersion

When the artificial soil manufactured by the present invention is used as a daily cover material for landfills, it must have the required strength and at the same time, the reslurrification phenomenon and the strength reduction phenomenon caused by the inundation such as heavy rain and heavy snow, which are the climatic characteristics of Korea, should not occur. something to do. Therefore, in this experiment, the uniaxial compressive strength changes before and after 1 day immersion were investigated for artificial soils cured for 3 days.

The change in uniaxial compressive strength before and after immersion is shown in Table 5 below. As can be seen through this, the artificial soil prepared by Example 1 is -0.1kg / kg / cm ² , and the artificial soil prepared by Comparative Example 1 is -0.2kg / cm ^2. The rate of change of strength was shown.

As can be seen from the above results, when the high calcium slag dust is mixed, the uniaxial compressive strength change before and after the inundation of artificial soil is relatively reduced. It is judged that no obvious water absorption occurs. Therefore, when the artificial soil prepared by the present invention is used in landfill, reslurrying or strength reduction phenomenon due to flooding due to snowfall is insignificant. do.

Strength expression at early age following the addition of the solidifying agent is achieved by the C-S-H gel in which the strength-expressing agent is formed simultaneously with a large amount of ethringite. In addition, the C-S-H gel fills the voids of the hardened paste tightly, forming a dense networked network structure with ettringite and continuously expressing high strength. Therefore, if the content of the strength-expressing agent is increased according to the use of the solidified, it can express the strength that can be utilized not only for the cover material but also for various ground materials such as the fill material, the order material, and the backfill material.

In particular, unlike the comparative example, the embodiment further includes high calcium slag dust, and thus, in addition to the pozzolanic reaction of the high calcium fly ash, the latent rigidity of the high calcium slag dust is complex, resulting in less change in strength due to more dense tissue formation.

Before immersion (kgf /) After immersion (kgf /) Intensity change Example 1 4.2 4.1 0.1 Example 2 5.2 5.1 0.1 Comparative Example 1 3.9 3.7 0.2 Comparative Example 2 4.5 4.3 0.2

(4) Permeability characteristics

Table 6 shows the permeability coefficient of the artificial soil prepared by Example 1 and Comparative Example 1. The permeability coefficient was 1.11 × 10 ^{−6 in} Example 1 and 1.24 × 10 ^{−6 in} Comparative Example 1, respectively, at 3 days of age. If you look at the national standard for permeability of cover material, the waste management law only specifies the thickness of the cover material, but it does not provide any specific standard. However, in the Middlesex country of New Jersey, the permeability coefficient of landfill cover is 1 × 10 ^-3. In view of what is presented in cm / sec to 1 × 10 ⁻⁷ cm / sec, the artificial soil prepared by the present invention is considered to have a sufficient permeability function as a landfill daily and intermediate cover material.

In particular, in Example 1, unlike the Comparative Example 1, the high calcium slag dust is further included in addition to the pozzolanic reaction of the high calcium fly ash, combined with the latent rigidity of the high calcium slag dust, the water permeability coefficient is lowered by more dense tissue formation.

 Permeability coefficient Example 1 1.11 × 10 ^-6 Comparative Example 1 1.24 × 10 ^-6

(5) pH change characteristics

Table 7 shows the pH changes according to the natural curing date of the mixture of sewage sludge and solidifying agent. As a result of the experiment, Example 1 shows a change from strong alkali to weak alkalinity at pH 11.5 or less from 3 days when the physical change of sewage sludge is finished. I think you can.

In particular, unlike the comparative example, the Example further includes high calcium slag dust, which shows a high alkaline state, but shows a characteristic of decreasing pH from the 3rd day of age, which shows that the high calcium slag dust has a rapid initial reactivity compared to the high calcium fly ash. This is because the pH of the Free-CaO and FeO components gradually decreases after the reaction with water.

Immediately after mixing 3 hours after mixing 1 day 3 days 7 days 14 days Example 1 12.4 11.8 11.6 11.3 9.2 8.9 Example 2 12.6 12.5 11.0 10.7 9.0 8.8 Comparative Example 1 12.2 11.7 11.6 11.5 9.3 9.1 Comparative Example 2 12.5 11.7 11.5 11.5 9.6 9.1

(6) Odor control (ammonia)

Sewage sludge mainly produces odors due to the decomposition of organic matter. As the pH rises, the activity of microorganisms decreases and the decomposition of organic matter in the sludge is also stopped, resulting in the inherent odor of sewage sludge. However, when the quicklime and sewage sludge are mixed, severe odor is generated, which is the biggest problem in the lime stabilization process with ammonia gas which is rapidly released as the pH rises.

This is because the ammonia present in the soluble ammonium ion state in the neutral region is released as the nonionic ammonia gas with the rise of pH.

In order to evaluate the malodor control ability of the solidifying agent according to the present invention, the artificial soil produced by Example 1 and the artificial soil produced by Comparative Example 1 below, which is a conventional general artificial soil manufacturing method, were tested. Table 8 shows.

Ammonia Detection Over Time Classification Example 1 Comparative Example 1 Measuring position
Measuring time surface inside surface inside Immediately after mixing 130 150 150 180 1 hours 55 110 70 130 3 hours 15 35 30 50 6 hours 10 15 15 25 12 hours 5 5 5 10 24 hours 5 5 5 5 72 hours 5 5 5 5

According to Example 1, ammonia odors of 130 ppm on the surface and 150 ppm on the inside were detected immediately after mixing of the sewage sludge and the solidifying agent, and gradually decreased over time. After 6 hours, the surface was 10 ppm on the inside and 15 ppm on the inside. Decreased to a degree.

Compared with Comparative Example 1, which does not contain high calcium slag dust, the odor reduction performance of the artificial soil according to the present invention was confirmed. This is thought to be controlled through physical adsorption due to the adsorption of ultra-fine particles of high calcium slag.

(7) heavy metal elution

Table 9 below shows the heavy metal elution test results of the artificial soil prepared by Example 1. As can be seen, most of the heavy metals were not eluted. This is because the heavy metal is substituted or fixed into the crystal structure by being fixed by the hydrate generated in the hydration reaction. Therefore, the elution concentration in all these experiments is much lower than the standard value or is not detected so that the sewage sludge is solidified and used as daily cover material, land reforming material and landfill material. I don't think so.

Hazardous Substances
Dissolution Method CD As Pb Hg Cr ⁶⁺ Cu Org.P TCE PCE Domestic standard
(KSLP) Reference value 0.3 1.5 3.0 0.05 1.5 3.0 1.0 0.1 0.3 Solid N.D. N.D. 0.002 N.D. N.D. 0.22 N.D. N.D. N.D. US EPA
(TCLP) Reference value 1.0 - 5.0 0.2 5.0 - - - - Solid N.D. - 0.005 N.D. 0.003 - - - -  N.D: Not Detected

(8) Small model test evaluation to evaluate the stability of cover material in landfill

The small model test is to test the performance of the cover material during actual landfilling. A cylinder with a diameter of 10cm and a height of 15cm is manufactured, and a valve is installed in the lower 4cm portion. The sewage sludge solidified in Example 1 is placed in the upper 11cm space. After mixing the seawater at the ratio of 10, 20, 25, 30, 35, 40, 45%, after 28 days, the condensation test is performed with a compression tester to calculate the strength. pH, heavy metal content test and organic matter content were measured.

As a result, environmental engineering experiments such as pH, organic matter, heavy metal leaching, BOD and COD showed weak alkalinity with pH of 8.5, and heavy metal leaching was (Cd, Cu, Pb, Cr, Zn) of 0.001 ~ 0.3025. The Enforcement Rule, Leachate Emission Standard, was satisfied. In addition, BOD and COD also satisfies the 150 mg / L and 70 mg / L values specified in the Waste Management Act.

(9) Soil test for evaluation of settlement amount of cover material at landfill

Soil test was conducted to analyze the settlement amount of cover material at the time of landfill using 105 cm high, 42 cm wide and 78 cm long. The solids of Example 3 were placed in the earthenware and loaded up to 500 kg, and the load and settlement according to time were observed. The results of the soil test showed that almost all settlements occurred within 80 hours. In other words, the artificial soil produced by the present invention is not settled long enough to be used as a landfill cover material.

As a result of all experiments, the artificial soil produced by the present invention can be said to be highly applicable as cover soil and landfill material. The results are summarized in Table 10 below.

division  Performance Value of Artificial Soil Prepared by the Present Invention Mixture appearance Natural ocher Reslurry None (after 3 days of age) Ammonia odor 15 ppm
(3 hours after curing, 10 cm of mixture surface) pH Day 3: pH 11.6
14 days: pH 8.9 Moisture content 44.3% (3 hours after mixing) Uniaxial compressive strength Fit (4.2kgf / cm ² , 3 days old) Heavy metal elution Appropriate (age 3 days, baseline 1/10 or less) Small model test (BOD, COD) BOD 10 (baseline 150 mg / L)
COD 40 (baseline 70 mg / L) Earthwork Experiment Almost all settlements occur within 80 hours

Claims (11)

In the solidifying agent for solidifying organic sludge,
With respect to 100 parts by weight of paper sludge incinerator having a calcium oxide (CaO) content of 35 to 70%,
10 to 50 parts by weight of high calcium fly ash, which is generated in a furnace desulfurization type coal combustion boiler and has a calcium oxide content of 40 to 75%,
10 to 200 parts by weight of high calcium slag dust having a calcium oxide (CaO) content of 40 to 80%,
The paper sludge incineration material, high calcium fly ash and high calcium slag dust has a specific surface area of 2,000 ~ 9,000 / g organic sludge solidifying agent.


delete The method of claim 1,
An organic sludge solidifying agent, characterized in that it further comprises a heating agent to increase the exothermic reaction with the organic sludge.
The method of claim 3,
The heating agent is an organic sludge solidifying agent, characterized in that any one or a mixture of two or more selected from the group consisting of quicklime powder, light dolomite powder and petroleum coke ash ash powder.
The method of claim 4, wherein
The heat generating agent is an organic sludge solidifying agent, characterized in that mixed 5 to 50 parts by weight based on 100 parts by weight of the papermaking sludge incineration.
The method of claim 1,
Organic sludge solidifying agent further comprises a pH reducing agent in order to prevent odor generation and heavy metal elution of the solidified solidified organic sludge.
The method according to claim 6,
The pH reducing agent may be any one or a mixture of two or more selected from the group consisting of acid powder suitable for sulfuric acid powder, sodium aluminum sulfate (SAS) powder and sodium aluminum fluoride (SAF) powder which are by-products generated during the polysilicon manufacturing process. Characterized organic sludge solidifying agent.
The method of claim 7, wherein
The pH reducing agent is an organic sludge solidifying agent, characterized in that mixed 5 to 50 parts by weight based on 100 parts by weight of the papermaking sludge incineration.
1) preparing a solidifying agent of any one of claims 1 and 3 to 8;
2) measuring 5 to 80 parts by weight of the solidifying agent based on 100 parts by weight of organic sludge;
3) mixing the metered organic sludge with a solidifying agent;
4) curing the mixture of organic sludge and solidifying agent; And
5) If the pH reducing agent is not included in the hardener, adding a pH reducing agent to the mixture and mixing; artificial soil manufacturing method comprising a.



delete 10. The method of claim 9,
The pH reducing agent is artificial soil manufacturing method, characterized in that for adding 10 to 100 parts by weight based on 100 parts by weight of the papermaking sludge incineration.

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