KR100926382B1 - Method of producing filter material comprising bottom ash - Google Patents

Abstract

PURPOSE: A method for manufacturing water-purifying material including bottom ash is provided to supply the water-purifying material with inexpensive by recycling landfill ash efficiently. CONSTITUTION: A method for manufacturing water-purifying material including bottom ash includes the following steps of: performing a transfer process by collecting landfill ash from a reclaimed land(S1,S2); performing a distributing process of the transferred landfill ash(S3); performing a sorting process of the separated landfill ash according to particle size(S4); performing a micropowder separating process removing the micropowder after performing a washing process(S5,S6); performing a dehydration process dehydrating the landfill ash(S8); and performing a disinfection process of the dehydrated landfill ash(S9).

Description

Method for producing water purification material containing bottom ash {Method of producing filter material comprising bottom ash}

The present invention relates to a method for producing a water purifying material, and more particularly, to a method for manufacturing a water purifying material including bottom ash produced by treating a buried ash.

Most coastal farming and reclamation projects in Korea are carried out in the bay with few waves, and there is little distribution of seawater and low quality in the bay, and the water quality is contaminated by the continuous inflow of pollutants from the land. In particular, the quality of the water is low due to a decrease in pH, a decrease in dissolved oxygen, an increase in nutrients, and an increase in H2S, which makes it harder for living in the bottom layer. It is becoming.

Water purification material is used to purify water quality in the agricultural and fishery industry and other industrial fields. A large amount of water purification material is used for agriculture and fisheries and for industrial purposes. In the case of natural materials such as sand used as conventional water purification material Although the price is low, the water purification performance is low and the weight is heavy, so the practical use is limited. On the other hand, activated carbon and zeolite are used for treating influent and discharged water generated in farms or reclamation projects in Korea because of their excellent adsorption efficiency of pollutants, but most of them are expensive because they are imported from foreign countries or produced by adopting their manufacturing technology. Since the supply is not smooth, it is difficult to use widely as a water purification material. In particular, in the case of a sintered body such as zeolite, there is a limit that it becomes difficult to use for a long time due to the pore clogging phenomenon occurs as the use time is longer.

On the other hand, in coal-fired power plants, landfill ash (ash remaining after coal is burned) is continuously generated. Landfill ash can be classified into bottom ash (fly ash) and fly ash (fly ash), depending on where it occurs. Bottom ash is a ash falling under the boiler furnace of a power plant. Compared to the fly ash, fly ash has a fine powder form because it captures the scattering to the chimney after coal combustion. The occurrence rate of fly ash and bottom ash varies depending on the power plant, but it is generally about 80 to 85% by weight: about 15 to 20% by weight.

Coal is the cheapest and most abundant fuel in the world, and the construction of coal-fired power plants is continuously increasing. As a result, the amount of landfill ash has increased, resulting in more than 6 million tons of landfills annually. However, in the case of fly ash recycling, a large amount of fly ash is recycled with concrete admixtures, but in the case of bottom ash, only a part of the ash ash is recycled, and the rest is disposed of in landfills.

In this way, fly ash and bottom ash generated from coal-fired power plants are buried in water or underground, and the landfill ash which is thus disposed and discarded is called "landfill ash". Recently, it is difficult to secure landfills due to the increase of landfills, which causes various environmental problems and social problems, resulting in enormous obstacles to the operation of coal-fired power plants.

The present invention was developed in order to overcome the problems of the present situation as described above, by manufacturing water purification material using the landfill ash matured in a coal-fired power plant ash treatment plant for a long time, permeability, water retention of the bottom ash of the landfill It aims to show the water purification ability by filtration and adsorption of water pollutants and air pollutants by using intrinsic characteristics such as adsorption power.

In particular, the present invention recycles landfill ash, which has been discarded as waste, as a water purification material to prevent depletion of natural resources, and at the same time to supply users with water purification materials at an affordable price, thereby increasing the treatment efficiency of pollutants and increasing the amount of waste. It aims to contribute to environmental conservation through savings.

In the present invention, in order to achieve the above object, by collecting the aged landfill ash embedded in the ash processing plant of the power plant for a long time, classification, pulverization, powder removal, such as fly ash in the pore, other salt removal, harmful bacteria removal, effective Provided is a process prepared by microbial treatment, drying, or the like, a method of producing a water purification material mainly containing bottom ash is provided.

According to an embodiment of the present invention, since the landfill can be recycled as water purification material, it is possible to meet the national resource recycling policy, and to solve the problem of securing the landfill of power plants.

In addition, the present invention by using the landfill ash buried in the water for a long time to prevent the exhaustion of natural resources, at the same time to be able to supply the water purification material to users at a low price to increase the treatment efficiency of pollutants and Reducing the amount of waste contributes to environmental conservation.

Hereinafter, the present invention will be described in detail by explaining embodiments of the present invention with reference to the accompanying drawings. However, the present invention is not limited by the following examples.

1 is a flowchart illustrating a water purification material manufacturing process according to an embodiment of the present invention, Figure 2 is a schematic diagram of a manufacturing apparatus for producing a water purification material according to the present invention.

In the present invention, the water purification material is manufactured by using the landfill ash matured in a coal power plant ash processing plant for a long time, first, the landfill ash is collected from the ash processing plant (S1). Landfills can be either landfilled or landfilled, and landfillers are collected from the treatment plant using harvesting equipment such as dredging equipment, excavators, sand pumps or loaders. Collected landfill ash is transported to the workplace by the transfer means (10) (S2). When the landfill ash is collected by dredging equipment, the landfill ash collected through the pipeline can be transported, and when the landfill ash is collected by using the excavator or the loader, the conveyor belt when the moving distance is near. In case of a long distance, a dump truck can be used.

In order to improve the sorting efficiency of the hardened landfill ashes, the landfill ashes transferred from the ash processing plant are subjected to a classification process (S3). In the classification process, the landfill society is evenly divided and supplied to facilitate the disposal of the landfill assembly in a subsequent process. In FIG. 2, reference numeral 20 denotes a classification facility 20 for classifying a landfill meeting. As such a classification facility 20, in the wet method using a dredging facility, a classification storage tank of a square or circular tank can be used, and in the dry method, a distributor can be used to evenly classify the transferred landfill. At this time, in order to crush the landfill ashes which are stuck together due to the hardness, the treated water or fresh water may be sprayed at a high pressure. In this case, a high pressure pump and an injection nozzle for injecting the treated water or fresh water may be installed in the classification facility 20.

Thereafter, the classified landfill is separated by particle size through a screening process (S4). Through this sorting step (S4) it is possible to sort the bottom ash or fly ash to a desired size from the landfill. As the sorting facility 30, for example, a trommel or a plate-type vibrating sorting facility commonly used in a quarry or a sand quarry may be used. Specifically, the first stage has a net of 12.0 mm or 25.0 mm, and The stage may have a 3.0mm or 5.0mm web and a three-stage plate-type vibratory sorting system having a three-stage 1.6mm web. On the other hand, the bottom ash has a physical property that the surface is sharp, irregular and light due to the short production period. Therefore, the sorting efficiency may be lowered, so the sorting angle should be lowered by 1 to 2 ° than the general aggregate when the sorting facility is installed.

As such, during the sorting process or just before the process, a process (preliminary washing process) may be performed to wash the landfill ash using a washing liquid to remove fly ash, unburned carbon powder and other fine powder contained in the landfill ash. (S3-1). In the washing operation, by installing a washing nozzle to spray the treated water or fresh water at a high pressure to efficiently remove the fine powder contained in the landfill ash from the bottom ash, and also remove the chloride contained in the landfill ash . Washing equipment for the cleaning process can be installed on top of the sorting facility. However, this preliminary washing process may be omitted as necessary.

Since the bottom ash contained in the selected landfill ash may contain excessively large particles that are excessively inadequate for use as a water purifying material, a large size may be used by using a crusher 40 following the separation process if necessary. The shredding process of crushing the bottom ash is performed (S4-1). However, this shredding step is not necessary and may be omitted.

In Figure 2, the member number 50 is a storage facility 50 for temporarily storing the landfill ash classified by particle diameter after finishing the sorting process (S4), the member number 51 is a transfer pump for transporting the landfill ash completed the sorting process (S4) (51).

As a result of the screening process (S4) as described above, for the landfill ash that does not pass through the screening network (1.6mm mesh) having a mesh size of 1.6mm among the landfill ashes sorted by the particle size, chloride, fine powder and other Carry out a washing process (S5) to remove foreign matter. For the landfill ash which passed through the 1.6mm net, as described below, the landfill ash was administered in water to perform a fine powder separation process (S6) to remove suspended fines.

The washing step (S5) is the first washing step (S5-1) by spraying water, the second washing step (S5-2) through the deposition, or the third washing step (S5-) for washing the chloride removal chemicals 3) may be included. For example, in the sorting process (S4), the landfill ash that does not pass through the 1.6mm net, by spraying the treated water or fresh water at a high pressure by using a washing nozzle, chloride, fine powder and other foreign matter contained in the landfill ash To proceed to the first washing step (S5-1) to remove. If necessary, the additional sorting process (S4-2) may be further performed by using a sorting facility for the landfill ash which has undergone the crushing process before proceeding to the washing process (S5). In Figure 2, the member number 52 is a sorting facility 52 for proceeding the additional sorting process. Reference numeral 61 is a primary washing facility 61 for performing the primary washing step (S5-1), for example, may be composed of a nozzle.

After the first washing step S5-1, the second washing step S5-2 may be further performed. In the first washing step (S5-1), foreign matter adhering to the surface of the landfill ash is removed by water injection, but the chloride deposited in the pores of the landfill ash, specifically, the bottom ash is not easily removed. Therefore, in order to remove the chloride deposited in the pores of the bottom ash, it is possible to perform a second washing step (S5-2) that is deposited for a predetermined time in water. At this time, in order to increase the efficiency of chloride removal during deposition, it is also possible to use a commercially available chloride removal agent, such as sodium sulfite (NaSO) that is commercially available. In addition, if necessary, the method may further include a third washing step of additionally washing the second washed landfill ash using fresh water to remove chemicals used for desalination included in the second washed landfill ash. It may be (S5-3). In the drawings, reference numerals 62 and 63 denote tanks 62 and 63 as facilities for secondary and tertiary washing processes.

On the other hand, as mentioned above, the fine ash separation process is carried out for the landfill ash that passed through the 1.6mm mesh that can be divided into sorting facilities (30, 52) (S6). This differential separation process (S6) can be performed by the underwater injury separation method based on the principle of specific gravity difference using the flotation separation tank (70). In other words, when the landfill ash is put into the tank and a certain amount of water is supplied from the bottom, the particles having a large particle size are heavy and sink due to the difference in the floating pressure and specific gravity of the water, and the particles or fine powder (such as unburned carbon powder) are suspended. Particles having a particle size of about 0.3 mm or more are settled, and particles having a particle size of less than about 0.3 mm are suspended.

Thus, the landfill ash classified by particle diameter in the state in which small particles and fines are removed through the washing process and the fine powder separation process is subjected to the dehydration process (S7). As the dehydration facility 80 for such a dehydration step, a plate-type vibration dehydrator used for dewatering sand or fine aggregates or a belt press dehydrator used for sludge dewatering can be used.

Disinfection step (S8) is carried out for the landfill ash that has undergone the dehydration process, in order to remove the harmful microorganisms that may be contained in the pores of the landfill ash is reduced through the dehydration process using ozone or chlorine, etc. Will be done. Subsequently, the microbial treatment step (S9) is performed, in order to improve the water purification performance, to perform the microbial treatment step (S9) for attaching the useful microorganisms in the pores of the disinfected landfill. The effective microoganisms (EMs) are both anaerobic and aerobic and aerobic, present in the fertile soil while being harmless to all living things including humans. It refers to a composite of microorganisms and micro-aerobic microorganisms, which is a composite effective microorganism which is made to have a synergistic effect through extraction and synthesis of microorganisms. The useful microorganism itself is already known by Korean Patent Publication No. 10-2005-13683. In the present invention, the landfill ash is contained in the solution containing the useful microorganisms or the solution containing the useful microorganisms in the landfill ash is to carry out the microbial treatment step (S9) for the landfill ash.

In this way, the landfill ash that has undergone the microbial treatment step (S9) becomes a water purification material including bottom ash. The water purification material manufactured through this process may be additionally dried so that it may be easily stored in a separate place and easily used on site (S10). The drying process may be performed using various drying methods such as natural drying or drying using hot air. After finishing the drying process, the produced water purification product is packaged. It is easy to use and is packaged in various forms such as 5ℓ, 10ℓ, 20ℓ, 500ℓ, 1000ℓ.

Water purification material including the bottom ash according to the present invention made by such a manufacturing method exhibits a water purification function through a physical action and a chemical action. First, as a physical action, filtration by pores of the water purification material is exerted. In other words, by using the micro-gap that the bottom ash possesses, impurities such as suspension material are filtered out by the gap, and the filtration action is exerted. As another physical action, the adsorption action is exerted. The water purification material according to the present invention using the bottom ash has a lot of micropores, and since the adsorption of contaminants is made in these micropores, the water purification function is exerted accordingly. 3 shows an electron micrograph of a water purification material including a bottom ash prepared according to the present invention. As can be seen from FIG. 3, there are many pores inside the water purification material according to the present invention. Purification function is exerted.

On the other hand, the chemical action includes ion exchange action and precipitation production action. Since the water purification material according to the present invention using the bottom ash is mainly composed of inorganic ion exchange components AE2₂O₃ and SiO₂, ion exchange, formation of hydration products and co-precipitation of calcium carbonate occur, thereby removing various heavy metals. Chemical water purification will take place.

The water purification material manufactured according to the manufacturing method according to the present invention described above can be used by adjusting the particle size according to the use through the particle size adjusting process. That is, the particle size of the landfill ash can be classified according to the size and used according to the purpose of water purification materials.

Table 1 below is a particle size analysis result of the water purification material produced using the manufacturing method according to an embodiment of the present invention.

In Table 1, in the case of the water purification product 1 according to the embodiment of the present invention, the particle diameter is about 0.3 mm or more and less than 1.6 mm, and has a particle size of ordinary sand. Present at about 97 wt%.

In the case of the product (2) in Table 1, the particle diameter is about 1.6mm or more to less than 5.0mm is made of water purification material of the fine aggregate size.

In the case of the product (3) in Table 1, the particle diameter is produced from the water purification material of the coarse aggregate size of about 5.0mm or more to less than 12.0mm, and can be made into the product (1) or (2) by further crushing if necessary. have.

In the case of the product (4) in Table 1, the particle diameter is produced as a coarse aggregate size water purification material of about 12.0 mm or more to 50.0 mm or less, and if necessary, the product (1), (2) or (3) It can be prepared as.

On the other hand, in the case of landfill ash having a particle diameter of less than 0.3 mm in Table 1, in the manufacturing method step of the present invention described above, it can be produced using the landfill ash floating for specific gravity difference in the process of fine powder separation (S6), fine powder In the separation step (S6), the ratio of the landfill ash having a diameter of less than about 0.3 mm (based on 0.297 mm sieve) is about 92.8%, and when dehydrated and dried, it becomes a powder form. In the case of the landfill ash having a particle diameter of less than 0.3 mm, the ratio of bottom ash to fly ash is present in a ratio of about 70 wt%: 30 wt%.

Table 2 below shows the results of the detection of harmful substances carried out to confirm the environmental stability of the examples of the water purification material prepared according to the present invention. The test method was carried out according to the Waste Management Act standards, as shown in Table 2 below, the water purification material prepared according to the present invention was confirmed that the environmentally harmful substances are not eluted and safe. The numerical unit in Table 2 below is ppm.

On the other hand, nutrients are represented by nitrogen and phosphorus, which causes water pollution in manure or lakes, coasts, reclaimed lands, and farms through the activities of humans and animals, resulting in excessive reproduction of algae and deterioration of water quality. Deficiency and malodorous eutrophication causes fatal problems for aquatic organisms and fish farms such as fish. Using the water purifier prepared according to the present invention was carried out a test for the removal performance of nitrogen and phosphorus as the causative agent of eutrophication.

Specifically, according to the manufacturing method of the present invention, the product 1 of Table 1 in the form of sand and the product 2 of Table 1 in the form of fine gravel were prepared. For the polluted water, the livestock wastewater generated at the pig farm in Seocheon, Chungnam, Korea was concentrated for a long time, and the viscous wastewater was concentrated 20 times. In order to confirm the useful microbial effect of the water purification material according to the present invention, during the microbial treatment process, "EM active liquid" sold by Jeonju University was purchased and used, and the "EM active liquid" purchased was diluted 500 times.

Specifically, the test was performed according to the following steps.

1) Accurately take 30 liters of water purifying materials prepared by treating the landfill ash aged in the ash processing plant according to the production method according to the present invention, and put them in a plastic barrel 40 liters.

2) Dilute the useful microbial (EM) active solution 500 times with pure water.

3) Dilute 1.0ℓ of each livestock wastewater collected from pig farm 10 times.

4) Take 10ℓ of diluted useful microorganism active liquid and inject it into the water purifying material in the container.

5) Close the lid of the container containing the water purification material injected with the useful microorganism active liquid, deposit it for a certain time (16 hours in this test), and analyze the water quality.

Table 3 below summarizes the above test specifications.

Table 4 below is a result of analyzing the water quality of the sample of the water purification material according to the present invention deposited in the waste water according to the above test method.

As can be seen in Table 4, the sample (b) has a particle size similar to sand, it was confirmed that the filtration efficiency and pollutant removal performance is excellent. Sample (c) has a particle size of fine aggregate, which also shows excellent filtration efficiency and pollutant removal performance. Meanwhile, Samples (d) and (e) are prepared by diluting 500-fold dilution of useful microorganism (EM) active liquids into the samples (b) and (c) and undergoing a microbial treatment process. It was confirmed that the pollutant removal efficiency was much superior to that of the water purification samples.

As such, the water purification material according to the present invention has excellent filtering performance and ability to remove contaminants, and thus, when applied to a water pollution prevention facility, a significant effect can be obtained.

On the other hand, when the floating substances contained in seawater or fresh water (ground water) directly enter the farms, lakes, and rivers, they may enter as germs, and red tide occurs frequently due to the increase of marine pollution and seawater temperature. In addition, when contaminated water enters, various problems such as farming, appeal, and the death of fish in rivers occur due to the occurrence of diseases and difficulty in breathing.

In this situation, a test was conducted to confirm the performance of the water purification material according to the present invention. Table 5 below shows the test results.

In Table 5 above, the products (1), (2), (3), and (4) are the same as the products (1), (2), (3), and (4) of Table 1, respectively. As can be seen from, the product (1) and product (2) is excellent in the removal efficiency of the chemical oxygen demand (COD) and total nitrogen and the removal efficiency of total phosphorus as well as the removal efficiency of suspended solids. On the other hand, the products (3) and (4) were evaluated to be somewhat lower in purification efficiency than the products (1) and (2), respectively, and it was found that it is effective to use them as pre-filters.

Tests were also performed on the heavy metal removal performance of the water purifying material according to the present invention. Tables 6 to 8 below show the products of Table 1 in the heavy metal standard solutions (solutions having heavy metal concentrations of 10 ppm and 50 ppm, respectively). ) To (3) is a result of measuring the removal ability of heavy metals by depositing (shaking) for a predetermined time, Table 6 is the removal ability test results for copper (Cu), Table 7 is the removal ability test for zinc (Zn) Table 8 shows the results of the removal capacity test for lead (Pb).

Based on the above test results, the water purifying material according to the present invention may have different uses according to its particle size distribution. Table 9 below summarizes the recommended uses according to the particle size distribution of the water purifying material according to the present invention. will be. However, the use of the water purification material according to the present invention is not limited thereto.

1 is a flow chart for explaining the manufacturing process of the water purification material according to an embodiment of the present invention.

Figure 2 is a schematic diagram of the apparatus used in the manufacturing process of the water purification material according to an embodiment of the present invention.

       3 is an electron micrograph of a water purification material according to an embodiment of the present invention.

Claims (5)

As a method of manufacturing a water purification material containing bottom ash by collecting landfill ash containing bottom ash from a landfill site, Performing a process of collecting and transporting the landfill ash from the ash processing plant (S1-S2); Performing a process of classifying the transferred landfill (S3); Performing a sorting process of separating and classifying the classified landfill ash by particle size (S4); Of the landfill ashes classified and sorted by the particle size, the landfill ash that did not pass through the 1.6mm net was subjected to a washing process (S5) to remove chlorides, fine powder and other foreign matter, and to the landfill ash which passed through the 1.6mm net. For the step of performing a fine powder separation process (S6) to remove the suspended fine powder by administering in water; Dehydration step (S8) for dewatering the landfill ash; And Method of producing a water purification material including a bottom ash, characterized in that it comprises a step (S9) of sterilizing the dehydrated landfill. The method of claim 1, Subsequent to the disinfecting step (S9), the bottom ash comprising a microorganism treatment step (S10) of contacting the sterilized landfill ash with the useful microbial solution to attach the useful microorganisms in the pores of the landfill ash; Method for producing water purification material. The method according to claim 1 or 2, The washing step (S5), First washing the landfill ash by water spray (S5-1); And Method of manufacturing a water purification material containing a bottom ash, characterized in that it comprises a step (S5-2) of washing the landfill ash by immersing the first washed landfill ash in water. The method according to claim 1 or 2, The washing step (S5) is A method for producing a water purification material including a bottom ash, characterized in that it comprises a step of washing the landfill ash using a chloride remover. The method of claim 4, wherein Subsequent to the process of washing the landfill ash using a dechlorinating agent, Method of producing a water purification material, including bottom ash, characterized in that to further carry out the third washing step (S5-3) to wash the chloride removal agent by immersing the landfill ash in water.

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