Manufacturing method for anammox microbial granule including magnetite particles and anammox microbial granules prepared therefrom

Abstract

The present invention provides a method for manufacturing Anammox microbial granules attached with iron oxide particles, which can shorten the formation time of microbial granules manufactured using iron oxide particles produced by reverse co-precipitation as an internal carrier and maintain microbial activity to obtain stable and high contaminant removal performance, and Anammox microbial granules manufactured therefrom. To this end, the present invention comprises an iron oxide particle manufacturing step for manufacturing iron oxide particles; and a microbial granule granulation step for adding the manufactured iron oxide particles to a reaction vessel in which microbial granules are retained to induce granulation of microbial granules using iron oxide particles as an internal carrier. At this time, the iron oxide particle manufacturing step manufactures iron oxide particles through a reverse co-precipitation method in which a sodium hydroxide bulk solution is added in reverse to an iron precursor obtained by dissolving mill scale.

Description

Technology Field

[0001] The present invention relates to a method for producing Anammox microbial granules and Anammox microorganisms produced therefrom. More specifically, the invention relates to a method for producing Anammox microbial granules attached with iron oxide particles, which shortens the production time of microbial granules produced using iron oxide particles as an internal carrier and maintains microbial activity to obtain stable and high pollutant removal performance, and Anammox microbial granules produced therefrom. Background Technology

[0002] Arsenic is a heavy metal widely distributed in the environment in the form of various compounds and metalloids. In particular, the control of arsenic compounds in groundwater has become a critical global issue, as arsenic possesses fatal toxicity to the human body, such as causing skin cancer. Arsenic concentrations are particularly high in groundwater in Asia and Africa, and in some areas, levels exceeding 1,000 ppb are detected.

[0003] While methods such as coagulation, filtration-precipitation, adsorption, ion exchange, and membrane separation are known for removing arsenic, there is no significant disagreement that adsorption is the most efficient method when considering factors such as economic feasibility, field applicability, and ease of maintenance.

[0004] However, most adsorbents applied to arsenic-contaminated areas to date remain at the pilot stage due to factors such as high manufacturing costs, and currently face significant limitations in commercialization or large-scale expansion.

[0005] To overcome these limitations, reliance has been placed on empirical variations in the design or operation of arsenic removal processes; however, the need to understand the microbial community level has recently emerged. Given that biological processes depend on the coordinated activity of relevant microorganisms, it is predicted that microbial community composition will have a significant impact on the performance of arsenic removal processes.

[0006] Meanwhile, microbial granules have many advantages over plankton or biofilm forms due to characteristics such as high biomass density, small footprint, high resistance to chemical and oxygen exposure, and rapid inoculation into new reactors.

[0007] The formation of conventional microbial granules consumes a long time depending on the microbial growth rate and changes in environmental conditions, thereby delaying the start of the manufacturing process. In other words, the prolonged granule formation time and the inability to stably maintain microbial activity meant that high removal performance for contaminants, such as arsenic, could not be guaranteed. Prior art literature

[0008] Korean Registered Patent Publication No. 1890721 (Published Aug. 22, 2018) The problem to be solved

[0009] The objective of the present invention to solve the aforementioned problems is to provide a method for manufacturing Anammox microbial granules attached with iron oxide particles, which shortens the production time of microbial granules manufactured using iron oxide particles as an internal carrier and maintains microbial activity to obtain stable and high pollutant removal performance, and to provide Anammox microbial granules manufactured therefrom.

[0010] The problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art to which the present invention belongs from the description below. means of solving the problem

[0011] A method for manufacturing Anammox microbial granules attached with iron oxide particles according to an embodiment of the present invention for solving the above-mentioned problem comprises: an iron oxide particle manufacturing step for manufacturing iron oxide particles; and a microbial granule granulation step for adding the manufactured iron oxide particles to a reaction vessel in which microbial granules are retained to induce granulation of microbial granules using the iron oxide particles as internal carriers.

[0012] At this time, the iron oxide particle manufacturing step involves manufacturing the iron oxide particles through a reverse co-precipitation method in which a sodium hydroxide bulk solution (NaOH Bulk Solution) is added in reverse to a ferrous precursor obtained by dissolving mill scale.

[0013] In addition, the mill scale may contain Fe and O, and in this case, the total weight of the sum of Fe and O may exceed 90% by weight relative to the total weight of the mill scale.

[0014] In addition, the mill scale may contain 60 wt% FeO, 25 wt% Fe2O3, 8 wt% Fe3O4, and 7 wt% Si.

[0015] Meanwhile, the Anammox microbial granules according to an embodiment of the present invention can be manufactured by the method for manufacturing Anammox microbial granules with attached iron oxide particles described above. Effects of the invention

[0016] According to the present invention, mill scale, a byproduct of ironmaking, is used as a raw material for manufacturing iron oxide particles such as magnetite. Since the raw material itself is abundant in the ironmaking industry and its main component is iron oxide, it provides favorable conditions for producing magnetite. Accordingly, there is an advantage in that the cost of the manufacturing process can be significantly reduced.

[0017] According to the present invention, since iron oxide particles are manufactured through a reverse co-precipitation process, substances such as Fe(OH)3 or FeOOH are generated together, which can prevent problems such as the occurrence of red water over time during the operation of the arsenic adsorption module and has the advantage of ensuring stable adsorption performance over the long term.

[0018] According to the present invention, it has been confirmed that magnetite particles with a content of Fe and O of 90% or more can be produced by manufacturing magnetite using a simple acid treatment of mill scale and a reverse co-precipitation method using a base.

[0019] According to the present invention, experimental results using a column and plug flow reactor module confirmed that magnetite produced by the reverse co-precipitation method according to the present invention has an As(V) adsorption capacity of 9 mgAs / g or more, and through appropriate column reactor design, stable operation is possible to maintain the As(V) concentration of the treated water at 10 μg / L or less even during operation for more than one year (16,000 BV).

[0020] According to the present invention, it has been confirmed that when an adsorption material (magnetite) manufactured by the reverse co-precipitation method is stably applied, approximately 10 m³ of As(V) contaminated groundwater can be stably treated per 1 kg of material.

[0021] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention. Brief explanation of the drawing

[0022] Figure 1 is a schematic diagram showing the process of manufacturing magnetite, which is an iron oxide particle, using the hole-injection method. Figure 2 is a diagram showing the physicochemical properties of magnetite produced by the hole-injection method. Figure 3 is a diagram showing the particle size distribution of magnetite produced by the hole-draining method. Figure 4 is a diagram showing the effect of sodium hydroxide dosage (NaOH Dosage Rate) on the particle size distribution of ferrite particles during porosi. Figure 5 is a diagram showing the arsenic adsorption characteristics of magnetite produced by the hole injection method. Figure 6 is a diagram comparing the principle of manufacturing magnetite using the positive hole injection method and the principle of manufacturing magnetite using the reverse hole injection method according to an embodiment of the present invention. FIG. 7 is a block flowchart showing the process of manufacturing magnetite using a reverse co-precipitation method according to an embodiment of the present invention. FIG. 8 is a schematic diagram showing the process of manufacturing magnetite using a reverse co-precipitation method according to an embodiment of the present invention. Figure 9 is a figure showing a comparison of the FTIR spectra of magnetite produced by the reverse porositization method and magnetite produced by the positive porositization method according to an embodiment of the present invention. FIG. 10 is an exemplary diagram showing a column and plug-flow reactor module using magnetite prepared by the reverse co-precipitation method according to an embodiment of the present invention for an experiment on removing arsenic from water. Figure 11 is a diagram showing the effect of PZC and pH on arsenic adsorption of magnetite prepared by the reverse co-precipitation method according to an embodiment of the present invention during an underwater arsenic removal experiment. Figure 12 is a diagram showing the relationship between the adsorption desorption capacity and the cycle of adsorption and regeneration of magnetite produced by the reverse co-precipitation method according to an embodiment of the present invention during an underwater arsenic removal experiment. FIG. 13 is a diagram illustrating the amphoteric property of magnetite produced by the reverse co-precipitation method according to an embodiment of the present invention during an underwater arsenic removal experiment. FIG. 14 is a diagram showing the performance evaluation results of a column and a plug-flow reactor module using magnetite manufactured by the reverse co-precipitation method according to an embodiment of the present invention for evaluating the performance of removing arsenic from water. FIG. 15 is a diagram showing the change in particle size over time of microbial granules generally produced and the change in particle size over time of microbial granules when magnetite according to an embodiment of the present invention is used as an internal carrier. Specific details for implementing the invention

[0023] Preferred embodiments of the present invention, in which the problem to be solved described above can be specifically realized, are described below with reference to the attached drawings. In describing these embodiments, the same names and reference numerals may be used for identical components, and additional explanations thereof may be omitted.

[0024] A method for manufacturing Anammox microbial granules attached with iron oxide particles according to an embodiment of the present invention includes an iron oxide particle manufacturing step and a microbial granule granulation step.

[0025] The iron oxide particle manufacturing step may be a step for manufacturing iron oxide particles such as magnetite (Fe3O4).

[0026] The step of manufacturing iron oxide particles according to an embodiment of the present invention utilizes mill scale generated in the steel industry, dissolves the mill scale to obtain a ferrous precursor, and can manufacture iron oxide particles through a reverse co-precipitation process in which a sodium hydroxide bulk solution (NaOH Bulk Solution) is added in reverse to the obtained ferrous precursor.

[0027] At this time, the mill scale used may contain Fe and O, and the total weight of Fe and O combined may exceed 90 weight% relative to the total weight of the mill scale. The mill scale may contain 60 weight% FeO, 25 weight% Fe2O3, 8 weight% Fe3O4, and 7 weight% Si.

[0028] The microbial granule granulation step may be a step of inducing granulation of microbial granules using the iron oxide particles as internal carriers by adding the iron oxide particles produced in the iron oxide particle production step to a reaction vessel in which microbial granules are retained.

[0029] Using iron oxide particles, such as magnetite, as an internal carrier can significantly shorten the formation time of microbial granules and form high-density granules with fewer filamentous fungi. Additionally, the iron oxide particles used as an internal carrier can prevent the disintegration of microbial granules or hinder their aggregation. Furthermore, using high-density iron oxide particles as an internal carrier can improve the settling properties of microbial granules, thereby preventing loss.

[0030] In an embodiment of the present invention, pretreatment conditions for mill scale, which is ironmaking waste, and conditions for the generation of an iron precursor, conditions for the solubilization and reverse osmosis of mill scale, and physical and chemical properties of iron oxide particles, which are magnetite, as internal carriers for microbial granules are proposed.

[0031] In addition, in the embodiments of the present invention, the effect of magnetite as an iron oxide particle on the characteristics and microbial activity of Anammox microbial granules is determined, and the size distribution and filtration in solution of Anammox microbial granules containing magnetite are determined. Then, the SAA of Anammox microbial granules is evaluated, and the correlation of AHLs (Acylhomoserine Lactones) between magnetite and Anammox microbial granules is investigated.

[0032] In addition, in an embodiment of the present invention, the nitrogen removal characteristics of an experimental reactor module incorporating Anammox microbial granules containing magnetite are investigated, and a 2L capacity UASB low-energy nitrogen removal reactor incorporating MagG-AMX is operated to determine the effect of the amount of magnetite added to the MagG-AMX reactor module on SAA and nitrogen removal rates, and the performance of Anammox microbial granules using iron oxide particles such as magnetite as internal carriers is investigated by monitoring the microbial community characteristics of the Control (control group) and the MagG-AMX reactor module.

[0033] <Identifying the Effects of Iron Oxide Particles (Magnetite) on the Characteristics and Microbial Activity of Anammox Microbial Granules>

[0034] In naturally occurring Anammox microbial granules without inorganic additives, the microorganisms' EPS (Extra-cellular Polymeric Substances) and filamentous bacteria serve as important support structures. Generally, N2 gas is generated within the Anammox granules due to nitrogen removal; this gas becomes trapped by the slime layer on the outside, preventing easy discharge and causing it to accumulate. Consequently, the granules are highly susceptible to destruction due to increased internal pressure over time. Furthermore, the accumulated gas causes an overall decrease in specific gravity, leading to the granules easily floating to the surface of the reactor. Additionally, since the upper portion of the floating granules is prone to becoming oligotrophic, it becomes nearly impossible to maintain consistent activity.

[0035] On the other hand, MagG granules produced by adding iron oxide particles (magnetite) can overcome all the disadvantages of existing Anammox granules due to the porous characteristics and high specific gravity (5–5.5) of magnetite, and can act very favorably for the activation of Anammoxosomes by continuously supplying Fe2+ and Fe3+ depending on the chemical properties of magnetite. Therefore, by investigating the specific activity, size changes, and microbial community changes of Anammox microbial granules with added magnetite, magnetite can be a very effective internal carrier and core seed for single-stage Anammox operation.

[0036] <Elucidation of Nitrogen Removal Characteristics of a Reactor Module Applying Anammox Microbial Granules Containing Iron Oxide Particles (Magnetite)>

[0037] By operating a 1L capacity UASB-type low-energy nitrogen removal reactor module equipped with MagG-AMX, the effect of changes in the amount of magnetite added to MagG-AMX on SAA and nitrogen removal rates is evaluated, and the effect of changes in SSLE (Specific Sludge Load Equivalent, mg-magnetite / gTSS) (0–50.0) on SAA and nitrogen removal rates is determined. In addition, changes in the microbial community of the MagG-AMX reactor module with magnetite added as a core seed, along with the control group, are identified using high-throughput sequencing techniques to determine the nitrogen removal performance of Anammox microbial granules with magnetite applied.

[0038] <Expected Effects>

[0039] The method for producing Anammox microbial granules using magnetite produced by the reverse co-precipitation method according to the present invention as an internal carrier is expected to have the following effects.

[0040] First, this invention can establish new guidelines for the operation of Single-stage Anammox. Specifically, magnetite is a material exhibiting excellent photocatalytic effects that has been utilized for the decomposition of organic pollutants or the reduction of toxic substances. Due to its biocompatibility and chemical stability, it is widely used in biomedical science and biomass immobilization. However, due to the high cost of magnetite, there have been no cases of its application in water treatment using microorganisms to date. Furthermore, if successful results can be achieved by utilizing magnetite produced from mill scale as an adjuvant for Anammox microbial granules, it is expected to attract the attention of many researchers and have a significant impact on related engineering fields, given that Two-stage Anammox systems are currently being successfully disseminated and the demand for Single-stage Anammox development is rapidly increasing.

[0041] Furthermore, this invention demonstrates significant benefits in utilizing mill scale in terms of resource recovery. Currently, mill scale is treated as waste or recycled in the steel industry; however, as will be explained in detail later, producing magnetite by the reverse co-precipitation method of mill scale is not only important from a research and development perspective but also holds significant meaning from an engineering standpoint in that it recycles waste into high-value-added products.

[0042] Furthermore, when applied to processes requiring stable contaminant removal performance, the present invention allows for relative resistance to external inhibitory factors when operated with microbial granules, thereby enabling the rapid attainment of stable removal performance through rapid granule generation. Additionally, since rapid granule generation of slow-growing microorganisms is possible, this invention can be applied as a method for immobilizing microorganisms through granule generation in reactors where biomass loss may occur due to slow microbial growth rates.

[0043] Furthermore, when microbial granules are formed and stored according to the present invention, additional granules can be rapidly introduced into the reactor during operation when the shock load is severe. Additionally, for microbial species with slow growth rates, rapid granule formation can be expected by using magnetite containing iron, an essential trace element, as an internal carrier. Moreover, due to the high specific gravity of magnetite, using it as an internal carrier increases the specific gravity of the microbial granules, thereby effectively preventing loss.

[0044] Furthermore, while the conventional PVA-SA gel fixation method used for granule formation has the inconvenience of requiring separate microbial fixation, the present invention allows the microbial granulation process to occur naturally after magnetite is introduced into the reactor, thereby eliminating the need for additional processes for granule formation. Additionally, the PVC carrier serves only as a substrate for microbial attachment, and since the magnetite used as an internal carrier in the present invention slowly dissolves iron, an essential trace element for microorganisms, it can also be used as a stable iron reservoir.

[0045] In addition, the duration of conventional natural granule formation varies depending on the microbial species, and it is difficult to prevent microbial loss during the formation process. Since contaminant removal exhibits good performance when the microbial retention amount within the reactor is properly maintained, the present invention can easily achieve the desired removal performance through rapid microbial granule formation.

[0046] In addition, the present invention provides a surface to which microbial granules can attach, thereby facilitating rapid aggregation and creating a reactor dominated by microbial granules, which has the effect of stably responding to pollutant loads.

[0047] In addition, since the present invention utilizes high-density magnetite as an internal carrier, it is possible to increase the specific gravity of microbial granules during and after the granule formation process, thereby improving sedimentation properties.

[0048] The following provides a supplementary explanation of the iron oxide particle (magnetite) manufacturing step according to an embodiment of the present invention.

[0049] The iron oxide particle manufacturing step according to the present embodiment is characterized by utilizing mill scale generated in the steel industry, dissolving the mill scale to obtain a ferrous precursor, and manufacturing iron oxide particles through a reverse co-precipitation process in which a sodium hydroxide bulk solution (NaOH Bulk Solution) is added in reverse to the obtained ferrous precursor.

[0050] Here, the conventional Forward Co-precipitation Process and the Reverse Co-precipitation Process according to the present embodiment are compared as follows.

[0051] <Preparation of Iron Oxide Particles by Forward Co-precipitation Process>

[0052] Figure 1 is a schematic diagram showing the process of producing magnetite, which is an iron oxide particle, from mill scale using the hole infiltration method; Figure 2 is a diagram showing the physicochemical properties of magnetite produced by the hole infiltration method; Figure 3 is a diagram showing the particle size distribution of magnetite produced by the hole infiltration method; Figure 4 is a diagram showing the effect of sodium hydroxide dosage (NaOH Dosage Rate) during hole infiltration on the particle size distribution of ferrite particles; and Figure 5 is a diagram showing the arsenic adsorption characteristics of magnetite produced by the hole infiltration method.

[0053] The co-precipitation method is a technique for inducing co-precipitation in which mill scale generated in the steel industry undergoes pretreatment and particle size sorting processes to produce a dissolved iron precursor, and the generated iron precursor is introduced into a bulk sodium hydroxide solution with a pH of >12 to produce magnetite, which is an iron oxide particle. During this co-precipitation process, the particle size (3 to >300 µm) can be controlled by varying the addition rate (10 to 1,000 ml / min) of sodium hydroxide (NaOH).

[0054] However, when using the ion-infiltration method, a large amount of OH- penetrates into the magnetite crystals, generating a significant amount of chemically unstable brown Fe2O3 or FeOOH. Due to their relatively fast oxidation rates, Fe2O3 or FeOOH may be effective in the short term for the granulation of Anammox microorganisms, but there is a problem with reduced long-term effectiveness. For example, problems such as the occurrence of red water occur over time during the operation of the arsenic adsorption module.

[0055] On the other hand, the reverse co-precipitation method described below is a method of adding sodium hydroxide (NaOH) in reverse to an iron precursor, which can minimize the penetration of OH- into the crystalline structure of iron oxide particles such as magnetite.

[0056] <Preparation of Iron Oxide Particles by Reverse Co-precipitation Process>

[0057] FIG. 6 is a diagram comparing the principle of manufacturing magnetite using the positive co-precipitation method and the principle of manufacturing magnetite using the reverse co-precipitation method according to an embodiment of the present invention, FIG. 7 is a block example diagram showing the process of manufacturing magnetite using the reverse co-precipitation method according to an embodiment of the present invention, and FIG. 8 is a diagram schematically showing the process of manufacturing magnetite using the reverse co-precipitation method according to an embodiment of the present invention.

[0058] Here, the mill scale was 45–75 µm, aged at 70–80 degrees for 24 hours, and underwent a process of black ferrite particle formation and drying.

[0059] As explained earlier, magnetite was initially manufactured using the positive injection method; however, this method resulted in the co-generation of substances such as Fe(OH)3 or FeOOH, which caused problems such as the formation of red water over time during the operation of the arsenic adsorption reaction module. On the other hand, manufacturing magnetite using the negative injection method can resolve the problems associated with the positive injection method.

[0060] Figure 9 is a figure showing a comparison of the FTIR spectra of magnetite produced by the reverse porositization method according to an embodiment of the present invention and magnetite produced by the conventional positive porositization method.

[0061] FIG. 10 is an exemplary diagram showing a column and plug-flow reactor module using magnetite prepared by the reverse co-precipitation method according to an embodiment of the present invention for an experiment on removing arsenic from water.

[0062] Here, the basic specifications (Lab-Scale) of the module are a Column Height of 40.00 cm, a Mag. Packing Height of 20.00 cm, a Glass bead Height of 10.00 cm, an Inner Diameter of 2.00 cm, and a Cross-sectional Area of ​​3.14 cm². Additionally, the Mag. Particle Size is 150–300 μm, the Mag. Bulk Density is 2.30 g / cm³, the Mag. Packing Weight is 80 g, and the Input As Concentration is 0.10 mg / L. Furthermore, the EBCT is 0.50 hr, the Influent Flow Rate (calculated) is 125.66 ml / hr, the Influent Flow Rate (calculated) is 2.09 ml / min, and the EBV is 40.00 cm / hr. In addition, the daily treatment capacity is 3.02 L / d, and the daily As adsorbed amount is 0.27 mg As / d.

[0063] Also, the area of ​​each floor is 5600 mm2, the total area (8 floors) is 0.0448 m2, and the Mag. Weight is 80 g. In addition, the Input As conc is 0.10 mg / L, and the pH is 6.5 to 7.5.

[0064] Also, the influent flow rate (calculated) is 125.66 ml / hr, and the influent flow rate (calculated) is 2.09 ml / min. In addition, the daily treatment capacity is 3.02 L / d, and the daily As adsorbed amount is 0.27 mgAs / d.

[0065] The adsorption material (magnetite) prepared by the reverse co-precipitation method was applied to laboratory-scale column and plug-flow reactor modules to evaluate the arsenic removal performance of the treated water.

[0066] Each reactor module was operated stably for over a year based on a contact time of 30 minutes, and the influent arsenic concentration of each reactor module was set to 100 ppb based on As(V), and it was confirmed that the arsenic concentration of the treated water could stably satisfy the UN recommended standard of 10 ppb depending on the operation method.

[0067] Figure 11 is a diagram showing the effect of PZC and pH on arsenic adsorption of magnetite prepared by the reverse co-precipitation method according to an embodiment of the present invention during an underwater arsenic removal experiment.

[0068] Figure 12 is a diagram showing the relationship between the adsorption desorption capacity and the cycle of adsorption and regeneration of magnetite produced by the reverse co-precipitation method according to an embodiment of the present invention during an underwater arsenic removal experiment.

[0069] Here, the regeneration solution was 0.1N NaOH (100g magnetite / 1L regenerant), and the regeneration time was 2 hours, followed by washing three times and drying (70°C).

[0070] FIG. 13 is a diagram illustrating the amphoteric property of magnetite produced by the reverse co-precipitation method according to an embodiment of the present invention during an underwater arsenic removal experiment.

[0071] FIG. 14 is a diagram showing the performance evaluation results of a column and a plug-flow reactor module using magnetite manufactured by the reverse co-precipitation method according to an embodiment of the present invention for evaluating the performance of removing arsenic from water.

[0072] FIG. 15 is a diagram showing the change in particle size over time of microbial granules generally produced and the change in particle size over time of microbial granules when magnetite according to an embodiment of the present invention is used as an internal carrier.

[0073] As shown in the right side (B) of Fig. 15, it was confirmed that when magnetite according to the present embodiment was used as an internal carrier, the microbial granules were formed more quickly into large granules with a diameter of 1 mm or more.

[0074] As described above, the method for manufacturing Anammox microbial granules according to the present invention utilizes mill scale, a byproduct of ironmaking, as a raw material for producing iron oxide particles such as magnetite. Since the raw material itself is abundant in the ironmaking industry and its main component is iron oxide, it possesses favorable conditions for producing magnetite. Accordingly, there is an advantage in that the cost of the manufacturing process can be significantly reduced.

[0075] In addition, it was confirmed that by using a simple acid treatment of mill scale and a counter-precipitation method using a base according to the present invention to produce iron oxide particles such as magnetite, it is possible to produce magnetite particles with an Fe3O4 content of 95% or more.

[0076] In addition, experimental results using column and plug flow reactor modules confirmed that magnetite produced by the reverse co-precipitation method according to the present invention has an As(V) adsorption capacity of 9 mgAs / g or more, and through appropriate column reactor design, stable operation is possible to maintain the As(V) concentration of the treated water at 10 μg / L or less even during operation for more than one year (16,000 BV).

[0077] In addition, it was confirmed that when an adsorption material (magnetite) manufactured by the reverse co-precipitation method according to the present invention is stably applied, approximately 10 m³ of As(V) contaminated groundwater per 1 kg of material can be stably treated (from 100 ppb to 10 ppb or less).

[0078] As described above, preferred embodiments of the present invention have been explained with reference to the drawings; however, those skilled in the art may make various modifications or changes to the present invention without departing from the spirit and scope of the invention as described in the following claims.

Claims

Claim 1 Iron oxide particle manufacturing step for manufacturing iron oxide particles; The method comprises a microbial granule granulation step in which the manufactured iron oxide particles are added to a reaction vessel in which microbial granules are retained to induce granulation of microbial granules using the iron oxide particles as internal carriers, wherein the iron oxide particle manufacturing step manufactures the iron oxide particles through a reverse co-precipitation process in which a sodium hydroxide bulk solution is added in reverse to a ferrous precursor obtained by dissolving mill scale, wherein the mill scale contains Fe and O, and the total combined weight of Fe and O exceeds 90% by weight relative to the total weight of the mill scale, wherein the mill scale contains 60% by weight of FeO, 25% by weight of Fe2O3, 8% by weight of Fe3O4, and 7% by weight of Si, and wherein the iron oxide particles have an Fe3O4 content of 95% or more. A method for preparing Anammox microbial granules attached with iron oxide particles, characterized by having an As(V) adsorption capacity of 9 mgAs / g or more. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 Anammox microbial granules manufactured by the method for manufacturing Anammox microbial granules attached with iron oxide particles as described in claim 1, wherein the iron oxide particles are manufactured based on the mill scale containing 60 wt% FeO, 25 wt% Fe2O3, 8 wt% Fe3O4, and 7 wt% Si, and are characterized by having an Fe3O4 content of 95% or more and an As(V) adsorption capacity of 9 mgAs / g or more.

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