KR20120056154A - Ceramic composition for removing phosphorous and manufacturing method of thereof - Google Patents

Abstract

PURPOSE: A ceramic for removing phosphorus and a manufacturing method thereof are provided to economically remove dissolved low concentration phosphorus without any drug treatments by using olivine, zeolite, and slag. CONSTITUTION: A ceramic for removing phosphorus comprises 40-45 weight% of forsterite, 10-20 weight% of zeolite, and 40-45 weight% of slag. A manufacturing method of the ceramic material for removing phosphorus comprises the following steps: pulverizing forsterite, zeolite, and slag into powder and assorting thereof; mixing 40-45 weight% of forsterite, 10-20 weight% of zeolite, 40-45 weight% of slag; adding water to the mixture, kneading and molding the mixture; and plasticizing the product after drying thereof. The slag is a steel-manufacturing slag generated in a converter.

Description

Ceramic composition for phosphorus removal and manufacturing method thereof

The present invention relates to a ceramic composition for phosphorus removal and a method for manufacturing the same, and more particularly, to a ceramic composition for phosphorus removal and a method for producing the same, which can effectively remove phosphorus in a dissolved state which is difficult to treat biologically using ceramics. will be.

Conventional sewage and wastewater treatment facilities install screens at the inlet of sewage and wastewater treatment plants to treat organic substances, nitrogen, and phosphorus contained in sewage and wastewater, and separate suspended solids, etc. Nitrogen and phosphorus were removed and discharged to the stream.

Such stream discharge is regulated by law, and in order to satisfy these emission standards, conventionally installed and operated a high-level treatment facility (anaerobic, aerobic) to remove nitrogen and phosphorus by changing aerobic treatment method. Has come.

Currently, nitrogen and phosphorus treatment methods commonly used in sewage and wastewater treatment have been newly established to eliminate nitrogen and phosphorus, which are the main sources of eutrophication, by establishing an anaerobic and anaerobic tanks.

Biological nitrogen and phosphorus removal processes commonly used in these methods are most commonly used A2 / O series, MLE series, SBR series, etc. Recently, MBR series using hollow fiber membranes is installed and operated.

All of these treatments involve denitrification using nitrate as a hydrogen donor under anoxic conditions and decomposing POLY-P in cells under anaerobic conditions to induce the release of phosphorus, followed by dehydration by releasing microorganisms that overdose phosphorus under aerobic conditions. It is based on biological mechanisms to remove nutrients.

The conventional method described above has the advantage of being used for a long time as a method for removing phosphorus and having low maintenance costs, but the operating conditions for controlling microorganisms are difficult and the microorganisms for removing nitrogen and phosphorus prefer conditions that are opposite to each other. There was a problem in that the installation cost of the facility was to be separated by operating separately. In addition, as a control condition for removing phosphorus, many conditions such as temperature, dissolved oxygen concentration, SRT, and BOD / P balance were required in an anaerobic tank.

As a result, the wastewater treated and discharged from the wastewater treatment plant contains a large amount of residual phosphorus, and such wastewater flows into the stream, causing eutrophication of the stream.

Recently, to solve this problem, the Ministry of Environment recommends lowering the concentration of phosphorus in the discharged wastewater treatment facilities in the four major rivers to less than 0.5 mg / l and gradually applying it to all wastewater treatment plants in the country. It is planned to do so.

Phosphorus is a eutrophication that is several orders of magnitude higher than nitrogen, and removal of phosphorus is a very important way to protect rivers. Since the removal concentration of phosphorus by the conventional microorganism is difficult to remove less than 0.5 mg / ℓ has been proposed a treatment method for solving this.

Conventional techniques for solving the above problems have been proposed as a method of removing phosphorus by administering a drug that reacts with phosphorus as a method that is expensive compared to biological treatment and has a problem of generating sludge but has a very high efficiency.

In the case of the method of administering a drug, it is a method of condensing and separating phosphorus by administering aluminum salt or iron salt, which is usually inexpensive and easy to supply, and is very efficient, easy to operate, and easily responds to load fluctuations. Moreover, the removal efficiency is very stable even if the discharged water discharged by the deterioration of microbial state contains a large amount of suspended solids.

However, in order to enlarge the coagulated fine colloidal particles, a large amount of inorganic coagulant and an organic coagulant need to be administered. It is difficult to apply sequentially to existing sewage and wastewater treatment plants with a large flow rate and narrow land area.

The present invention has been made to improve the above problems, and a ceramic composition and a method for preparing the same, which can be removed in a simple and economical way without using a separate chemical treatment of low concentration phosphorus in the biologically difficult dissolved state using a ceramic The purpose is to provide.

Phosphorus removal ceramic composition of the present invention for achieving the above object is characterized in that it contains olivine, zeolite, slag.

40 to 45% by weight of the olivine, 10 to 20% by weight of the zeolite, 40 to 45% by weight of the slag is characterized in that the composition is mixed.

And the method for producing a ceramic composition for phosphorus removal of the present invention for achieving the above object comprises a crushing step of crushing the olivine, zeolite, slag by powder; A mixing step of mixing 40 to 45 wt% of the olivine, 10 to 20 wt% of the zeolite, and 40 to 45 wt% of the slag; A molding step of kneading by adding water to the mixture obtained in the mixing step and then molding into a molded body; It characterized by comprising a; firing step of drying the molded body after firing.

The slag is characterized in that the steel slag generated in the converter.

As described above, according to the present invention, a low concentration of phosphorus in a biologically difficult dissolved state can be removed in a simple and economical manner without a separate chemical treatment.

In addition, high treatment efficiency can be obtained regardless of wastewater characteristics in the removal of phosphorus.

1 is a graph showing the concentration of phosphorus as a result of phosphorus removal experiments,
2 is a graph showing phosphorus removal efficiency as a result of phosphorus removal experiment.

Hereinafter, a ceramic composition for phosphorus removal according to a preferred embodiment of the present invention and a manufacturing method thereof will be described in detail.

The ceramic composition for phosphorus removal of this invention contains olivine, zeolite, and slag.

Olivine is a silicate mineral belonging to the tetragonal system, and has a strong alkalinity of pH 9.1-9.3. The main component is SiO ₂ , Al ₂ O ₃ , and Fe ₂ O ₃ , which are adsorption-induced oxidation minerals. Finely ground olivine has a large surface area and is excellent in the ability to remove phosphorus. Preferably the olivine is micronized to 200 to 300 mesh particle size to increase the surface area in contact with water.

In addition, olivine contains CaO, MgO, K ₂ O, Na ₂ O, and exhibits a strong alkaline state due to OH ⁻ generated by their hydrolysis, so that heavy metal ions can be adsorbed and removed. The main components of the olivine applied to the present invention are shown in Table 1 below.

ingredient SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO  MgO Content (wt%) 39 1.5 11.2 3.3 35.0

The zeolite is a hydrous aluminosilicate containing Si and Al as main components and a small amount of Na, K, Ca, Mg, Sr and Ba as cations. In terms of crystal structure, all of the oxygen in the (Si, Al) O ₄ tetrahedron, one of the basic units of silicate minerals, is shared by another tetrahedron and belongs to a three-dimensionally linked reticilicate mineral (tectosilicate). The bonds of the atoms are loose in crystal structure, and even though the moisture filling the spaces is released at high heat, the skeleton remains the same, so that other fine particles can be adsorbed. Preferably the zeolite is micronized to a size of 200 to 300 mesh particle size to increase the surface area in contact with water.

Zeolite applied to the present invention is taken from nature, for example, the main components of the zeolite are shown in Table 2 below.

ingredient SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO K ₂ O Na ₂ O Content (wt%) 66.6 13.1 0.7 1.7 0.4 4.78 1.44

And slag (slag) using the slag generated in the steelmaking process or steelmaking process of the steel mill. Slag is divided into blast furnace slag and steelmaking slag according to the type of furnace used. Blast furnace slag is produced in the process of manufacturing pig iron from iron ore at high temperature, and steelmaking slag is produced in the process of refining pig iron in the converter to remove impurities such as carbon, phosphorus and sulfur. In addition, pretreatment slag generated in the pretreatment process of steelmaking, refining furnace slag of a stainless steelmaking process, etc. can be used. The slag is separated from the waste water by using the difference in specific gravity, and it is classified into palletized slag-air cooled in the air and granulated slag-water cooled by spraying water according to the cooling method. Can be. Preferably, steelmaking slag generated in the converter is used as slag.

Slag is micronized to 200 to 300 mesh particle size to increase the surface area in contact with water. The composition of the steelmaking slag applied in the present invention is shown in Table 3 below.

ingredient SiO ₂ CaO Fe ₂ O ₃ Al ₂ O ₃ MgO MnO TiO ₂ S Content (wt%) 13.3 44.3 17.5 1.5 6.4 5.3 1.5 0.07

Hereinafter, the manufacturing method of the ceramic composition for phosphorus removal is demonstrated.

First, a crushing step of crushing olivine, zeolite and slag into powder is performed. Olivine, zeolite and slag are micronized to increase the contact area with water. Preferably micronized to 200 to 300 mesh particle size. In the crushing step, the collected ore is pulverized using a hammer mill, a ball mill, a roche mill, and the like, and then screened using a sieve of 200 to 300 mesh.

Next, the materials ground in the mixing step are mixed at a predetermined ratio. Preferably 40 to 45% by weight of olivine, 10 to 20% by weight of zeolite and 40 to 45% by weight of slag are mixed.

In addition, water is kneaded by adding water to the mixture obtained in the mixing step, and then a molding step of molding into a molded body having a desired shape and size is performed. The shaped body may be shaped into a spherical or square, pellet form. In the forming step, a binder may be added in addition to water for forming strength. The binder firmly binds the fine powders and allows the adhesion to be maintained even upon firing and immersion. The binder may be mixed in a weight ratio of 20 to 30% relative to the total weight of the olivine, zeolite and slag. Methyl cellulose may be used as the binder.

The molded body is dried in a drying chamber or the like and then calcined at 800 to 1000 ° C. for 30 to 90 minutes to solidify.

Hereinafter, the manufacturing method of the present invention will be described through examples. However, the following examples are intended to illustrate the present invention in detail, and the scope of the present invention is not limited to the following examples.

(Example 1)

Olivine, zeolite and slag were ground and screened using a 250 mesh sieve. The fine powder thus obtained was mixed at a ratio of 40% by weight of olivine, 20% by weight of zeolite, and 40% by weight of slag, and then kneaded with water, and dried. After drying, the mixture was put in an electric furnace and fired at 900 ° C. for 60 minutes to prepare a ball-shaped ceramic composition having a size of about 2 to 4 mm.

(Example 2)

To prepare a ceramic composition in the same manner as in Example 1, 45% by weight of olivine, 10% by weight of zeolite, 45% by weight of slag was mixed.

(Comparative Example 1)

A ceramic composition was prepared in the same manner as in Example 1, but olivine and zeolite were used, and the composition was mixed in a ratio of 70% by weight of olivine and 30% by weight of zeolite.

(Comparative Example 2)

To prepare a ceramic composition in the same manner as in Example 1, using olivine and slag, the composition was mixed in a ratio of 70% by weight of olivine, 30% by weight of slag.

(Comparative Example 3)

A ceramic composition was prepared in the same manner as in Example 1, but slag and zeolite were used, and the composition was mixed at a ratio of 70 wt% slag and 30 wt% zeolite.

Experimental Example: Phosphorus Removal Experiment

Artificial sewage was prepared by dissolving KH ₂ PO ₄ reagent in tertiary distilled water to adjust the concentration so that the phosphorus content was 19.352 mg / l.

1 L of the prepared artificial sewage was added to a 2.4 L reactor, and the ceramic composition was added at a rate of 10% (W / V). In other experimental conditions, the reaction was performed at a water temperature of 25 ° C., a reactor rotation speed of 140 RPM, and a reaction time of 24 hours.

The total phosphorus concentration in the artificial sewage was measured through the experiments using the ceramic compositions of Examples and Comparative Examples, respectively, and is shown in the graphs of Table 4 and FIG. 1.

division Before experiment Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 T-P (mg / l) 19.352 0.841 0.655 0.289 0.100 0.056

In the graph of FIG. 2, the concentration of phosphorus after the experiment with respect to the initial concentration of phosphorus before the experiment was represented as removal efficiency. For reference, in FIG. 1 and FIG. 2, case1 refers to Comparative Example 1, case2 refers to Comparative Example 2, case3 refers to Comparative Example 3, case4 refers to Example 1, and case5 refers to Example 2.

Referring to Table 4 and FIGS. 1 and 2, it can be seen that phosphorus removal efficiency is very excellent when using the ceramic compositions according to Examples 1 and 2 of the present invention. In the case of the embodiment it can be seen that the phosphorus removal efficiency is more than 99%. And Example 2 showed a somewhat higher effect than Example 1.

On the other hand, the comparative examples were found to have a lower phosphorus removal efficiency than the embodiments. From these results, it can be seen that when the ceramic composition is prepared by mixing all three types of olivine, zeolite, and slag, the phosphorus removal efficiency is increased compared to using only two materials of olivine, zeolite, and slag. have.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation.

Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

Claims (4)

A phosphate ceramic composition for phospholipids containing zeolite, zeolite and slag. The ceramic composition for phosphorus removal according to claim 1, wherein 40 to 45% by weight of the olivine, 10 to 20% by weight of the zeolite, and 40 to 45% by weight of the slag are mixed. A crushing step of crushing olivine, zeolite and slag by powder;
A mixing step of mixing 40 to 45 wt% of the olivine, 10 to 20 wt% of the zeolite, and 40 to 45 wt% of the slag;
A molding step of kneading by adding water to the mixture obtained in the mixing step and then molding into a molded body;
And a firing step of firing the molded body after drying the molded body. The method of claim 3, wherein the slag is steelmaking slag generated in the converter.

Images