KR20030080689A - Ceramic Media Cured at low Temperature for Wastewater Treatment using Wastes and Method of Manufacturing such Media - Google Patents

Abstract

PURPOSE: A ceramic media for biological wastewater treatment and a method for preparing the ceramic media using solid wastes at low temperature are provided. CONSTITUTION: The method comprises the steps of preparing a first mixture by mixing blast furnace slag cement 30 to 50 wt%, coal ash 20 to 40 wt.%, waste carbon 10 to 20 wt.%, kaolin 5 to 15 wt.%, zeolite 5 to 15 wt.%, and waste organic foam powder 1 to 2.5 wt.%; preparing a second mixture by mixing the first mixture with water containing 1.3 to 2.3 wt.% of fluidizing agent; molding the second mixture into a spherical shape with a diameter of 3 to 30 mm with an extrusion molding machine at a pressure of 1 to 20 kgf/cm¬2; and hardening the molded media, wherein the hardening process is subject to either low temperature calcination at 170 to 200 deg.C after drying the molded media at 10 to 25 deg.C for more than 20 days in shade or hydrothermal treatment at a pressure of 8.1 to 15.9 kgf/cm¬2 for 8 to 15 hrs after calcining the molded media at low temperature of 170 to 200 deg.C.

Description

Ceramic Media Cured at low Temperature for Wastewater Treatment using Wastes and Method of Manufacturing such Media}

The present invention relates to a ceramic carrier composition for wastewater treatment using various industrial wastes and a method for manufacturing the same. More specifically, industrial waste is a main component and easily attached various microorganisms capable of removing impurities from the wastewater. The present invention relates to a porous ceramic carrier having a space for growth and nutrients, and a method of manufacturing the same.

Since various wastewaters contain a lot of pollutants, chemical methods such as pH control and removal of some harmful substances are required. Also, a large amount of oxygen is required to decompose various pollutants. It is high in nutrients such as phosphorus, so it is necessary to remove the causative agents of eutrophication (green algae and red algae) of rivers, lakes and coastal seas.

Except for industrial wastewater containing excessively neutral pH or containing harmful components, biological methods are known to be most effective in treating various wastewater and wastewater, and biological methods can be roughly classified into activated sludge and biofilm processes.

Activated sludge method is a method to put microorganisms useful for wastewater and wastewater to be suspended and suspended in suspended state so that microorganisms can treat contaminants in wastewater and wastewater, and can be applied to anaerobic tank, anaerobic tank and aeration tank (oxygen supply). have.

This activated sludge method has the advantage of treating the sewage and wastewater of Daerang at low cost, but because the concentration of microorganisms in the reactor is low, the treatment speed is slow and the processing time is long, so a large capacity treatment tank is needed to secure a large amount of microorganisms. Problems include high initial capital investment costs, sludge swelling and a large amount of excess sludge, resulting in a sharp increase in the cost of treatment, and insufficient ability to cope with load fluctuations of influent wastewater.

These problems can be solved by the biofilm method and the purchase price of the carrier is a problem, but due to the problem solving ability as described above, the situation is gradually increasing and the installation place is increasing. In particular, the biofilm method has recently been pointed out as a problem of eutrophication, and is a way to reduce and solve the content of total nitrogen and total phosphorus, especially total nitrogen, which are expected to be strengthened.

The biofilm method fills an appropriate amount of microbial carriers (about 20-40%) in aeration tanks (which can be installed in anaerobic tanks and anoxic tanks), and microorganisms are attached to the carrier surface and pores with a large growth space to treat waste water.

Therefore, more and more kinds of microorganisms are stably attached to the carriers in large quantities to grow and treat waste and waste water, and microbial growth conditions are excellent as the microbial outflow to the next process tank is reduced and the composition of the carriers becomes a nutrient source for microorganisms. Wastewater treatment is active. Therefore, it is able to actively cope with the fluctuation of quantity and water quality of the inflow wastewater, and the microorganisms can be used continuously because there is little outflow of microorganisms, so the treatment efficiency is high.

The material of the microorganism carrier includes organic and inorganic materials, and organic materials include various polymer materials such as cellulose, polyethylene, polypropylene, polyvinyl chloride, and the like, and various inorganic materials such as fine ceramics, synthetic inorganic materials, and amorphous materials such as glass. , Sand, gravel and activated carbon are used.

The organic material may not provide a nutrient source of microorganisms, but may provide only a space for attaching and growing microorganisms, and thus, the performance of the organic material may be lower than that of the inorganic material, and the material itself may swell or deteriorate with time. Desorption of microorganisms occurs frequently, as well as a large amount of sludge generation and pollutants at disposal, which is difficult to process, but has a relatively low price.

Sand and gravel are still used in some of the mineral materials, but they were used in the early stages of wastewater treatment process development. They are cheap but low in microbial growth space, and activated carbon has good performance but is expensive and usually used in powder form. Therefore, it has to be added continuously and has the disadvantage that there is no microbial nutrient source except carbon.

Inorganic materials other than these three are excellent in heat resistance, chemical resistance and durability, can provide nutrients of microorganisms, and have various growth spaces due to the variety of pore size and number, and are similar to soil, so they are not disposed of after use. There is no advantage, but the disadvantage is that the price is higher than the organic material because of the high temperature firing process.

Therefore, it is desirable to develop an inorganic carrier that can adopt a low temperature firing process and utilize various wastes to lower the price.

In addition, the organic carrier has a number of pores, but the pore size is almost constant, there is a problem in that the various microorganisms are attached, there is a disadvantage that there is almost no substance that is a nutrient source of the microorganism.

An object of the present invention for solving the above problems is to utilize the unused or discarded minerals and various wastes as main components in Korea, while securing the physical properties of the mineral carrier having the above-mentioned advantages, and also has a price competitiveness Provides a porous carrier for wastewater and wastewater treatment using waste, which can solve the problem of manufacturing cost, which is a disadvantage of inorganic carriers, by using payment and firing it at low temperature below 200 ℃ to reduce energy cost for high temperature firing. There is.

Another object of the present invention is to add a variety of pore-forming agents to have a variety of sizes and many pores, by holding various elements necessary for the growth of microorganisms in the carrier, the attached microorganisms can continue to grow and reproduce without detachment The present invention provides a porous carrier for wastewater treatment and a method of manufacturing the same.

Another object of the present invention is to have various components in the carrier to neutralize the toxic components that may be present in the waste water, to provide the growth conditions of the microorganisms, and to form some of the impurities in the carrier that cannot be decomposed by the microorganisms. The present invention provides a porous carrier for wastewater treatment using waste which can play a role of removing and causing a chemical reaction, and a method of manufacturing the same.

Still another object of the present invention is to provide heat resistance, chemical resistance, and weather resistance of a general ceramic carrier, and to provide mechanical strength, that is, durability related to the life of the carrier, and a porous carrier for wastewater treatment using waste. And to provide a method for producing the same.

Carrier for wastewater treatment using waste, which is a constituent of the present invention which achieves the object as described above and removes the drawbacks of the related art, has a blast furnace cement of 30 to 50 wt%, coal ash 20 to 40wt%, and waste carbons. 10-20 wt%, 5-15 wt% of kaolin tailings, 5-15 wt% of zeolite tailings, 1-2.5 wt% of waste organic foam powder, and 1.3-2.3 wt% of a fluidizing agent.

In the above, the blast furnace cement refers to the blast furnace cement mixed with the general cement clinker by grinding the blast furnace slag produced as a by-product in the steel mill, the blast furnace slag containing 40wt% or more, general portland cement may be used. The reason why the composition section of the blast furnace cement is limited is that when the blast furnace cement is added at 30 wt% or less, the strength shortage of the carrier appears and when the addition is more than 50 wt%, the strength is increased but the amount of other components is decreased.

Coal ash refers to fly ash produced as a by-product from coal-fired coal or anthracite coal-fired power plants. Some of them are used as cement substitutes for concrete, but are still landfilled and cause dust generation and water pollution. It is a social issue.

Coal ash is composed mainly of silicon oxide (SiO ₂ ) and aluminum oxide (Al ₂ O ₃ ), besides calcium oxide (CaO), iron oxide (Fe ₂ O ₃ ), magnesium oxide (MgO) potassium oxide (K ₂ O), and oxidation Titanium (TiO ₂ ), sodium oxide (Na ₂ O) and manganese oxide (MnO) and the like is contained about 5wt% unburned carbon powder in the present invention may be a lot of unburned carbon powder, so the pretreatment for the removal of carbon powder no need.

The waste carbons contain carbon components, and the waste carbons are recycled after first use of waste coal or activated carbon.

The kaolin tailings may be of low grade and may be used unused or discarded. Zeolite tailings may refer to natural minerals and may also be of low grade or discarded.

The addition amount of the coal ash, waste carbons, kaolin and zeolite tailings is difficult because the above range is suitable and less is less effective addition effect and the addition amount of other active ingredients is reduced when a large amount is added.

The waste organic foam powder is preferably pulverized polystyrene, polyurethane, phenol foam, etc., which are discarded in the industry and at home, in the form of a powder (particle size of about 3 mm or less, especially 2 mm or less irregular size). The reason for the limitation as described above is that the pore formed when added to 1wt% or less is not sufficient, and when added to 2.5wt% or more, there is more space for microorganisms to attach and grow, but the viscosity of the carrier composition mixture is lowered and extruded. This is because the disadvantage is that the liquidity worsens.

The fluidizing agent may be added to improve the fluidity when the present carrier is manufactured in an extrusion molding method, and may use a fluidizing agent containing a foaming agent and a foaming agent containing a foaming agent. If it is 1.3 wt% or less, the fluidity is not improved. If the added amount is 2.3 wt% or more, the fluidity is so good that it is difficult to maintain the shape after extrusion molding.

As a step for mixing the raw materials as described above, a liquid component in which a fluidizing agent is added to water and the remaining powder composition are mixed, and then the two components are mixed again.

The mixture is molded using an extrusion method and is extruded into a cylindrical shape and then cut into an appropriate size to produce a spherical shape (3 ~ 30 Φ mm).

The manufacturing method of the carrier of the present invention will be described step by step as follows.

Method for producing an inorganic carrier of the present invention comprises the steps of first mixing the blast furnace cement, coal ash, waste carbons, kaolin and zeolite tailings and waste organic foam powder:

Mixing the second mixture by adding water containing a fluidizing agent to the first mixture;

Shaping the secondary mixture;

Curing the molded composition.

The molding step is produced in a spherical shape (3 ~ 30 Φ mm) using an extrusion molding machine at a pressure of 1 ~ 20 kgf / ㎠.

In the step of curing the composition, the composition is cured by curing at room temperature and calcining or by hydrothermal treatment. When curing at room temperature, the composition is left to cure in a shaded atmosphere of about 10 to 25 ° C. for about 20 days or more, and then sufficiently cured in a drying furnace. The carrier is prepared by hardening by low temperature baking at a temperature of 200 ° C. or by hydrothermal treatment for 8 to 15 hours at a pressure of 8.1 to 15.9 kg / cm 2 after low temperature baking at a temperature of 170 to 200 ° C.

Hereinafter, the configuration and the operation of the embodiment of the present invention will be described in detail.

<Example 1>

200 kg of blast furnace cement, 150 kg of coal ash containing about 6 wt% unburned carbon, 75 kg of low calorie coal, 50 kg of kaolin tailings, 50 kg of zeolite tailings and 7.5 kg of waste polystyrene foam powder, and 9 kg of a fluidizing agent added to about 175 kg of water After mixing, the two compositions were thoroughly mixed to prepare a homogeneous mixture.

The mixture was extruded into a cylindrical shape having a diameter of 8 mm in an extruder and then cut to prepare a carrier having a spherical shape of about 8 Φ mm.

The spherical carrier was left in the air for 3 hours and then cured by hydrothermal treatment for 12 hours at a temperature of about 180 ° C. and a pressure of about 11 atmospheres. The physical properties of the prepared carrier were 48 kgf / cm 2, specific gravity of 1.25, and specific surface area of 7.5 m 2 / g.

<Example 2>

Example 2 was prepared in the same manner as in Example 1 except that it was left in a shaded place for 28 days at a temperature of about 15 to 25 ° C. without hydrothermal treatment and then heated to 180 ° C. for 3 hours in a drying furnace. The physical properties of the prepared support were 52 kgf / cm 2, specific gravity of 1.24, and specific surface area of 7.7 m 2 / g.

<Example 3>

Example 3 was prepared in the same manner as in Example 1 except that activated carbon was used instead of low calorie coal, and the physical properties of the prepared carrier were 42 kgf / cm 2, specific gravity 1.23, and specific surface area. 8.3 m 2 / g.

<Test Example 1>

Wastewater treatment test was performed using the carrier prepared in Example 1.

Influent water was used for wastewater discharged from the dyeing plant. In pilot plant consisting of several water tanks, the carrier was injected into the aeration tank with a capacity of about 0.22m3 in weight ratio to the amount of wastewater. In order to do this, the prepared carrier was put in a disk-shaped organic case having a diameter of about 70 mm.

Water quality analysis was performed at steady state more than 1 month after the carrier was introduced. The hydraulic retention time was 6 hours and the results are shown in the table.

<Test Example 2>

The carrier prepared in Example 3 was tested in the same manner as in Test Example 1, and the results are shown in the table.

Comparative Example

It was tested in the same manner as in Test Example 1 using a commercially available hot-fired ceramic carrier (approximately 5Φ mm in size), and the carrier was put in a disc-shaped organic case for comparison under the same conditions. Is shown in.

<Table> Dyeing Wastewater Treatment Using Carrier

Analysis item Inflow water quality (mg / ℓ) Test Example 1 Test Example 2 Comparative example Existing Process Treatment water quality (mg / ℓ) % Removal Treatment water quality (mg / ℓ) % Removal Treatment water quality (mg / ℓ) % Removal Treatment water quality (mg / ℓ) % Removal BOD 105.9 5.3 95.0 5.5 94.8 14.7 86.1 6.3 94.1 COD _Mn 106.6 25.0 76.5 25.7 75.9 24.5 77.0 27.2 74.5 COD _Cr 257.7 49.2 80.9 48.9 81.0 65.3 74.7 47.9 81.4 SS 88.7 20.7 76.7 17.8 79.9 34.6 61.0 25.4 71.4 T-N 24.0 18.8 21.7 19.0 20.8 21.2 11.7 21.7 9.6 T-P 5.7 0.8 86.0 0.7 87.7 4.5 21.1 4.9 14.0 Chromaticity 1015.9 403.9 60.2 399.6 60.7 715.1 29.6 401.6 60.5

The treatment method in the existing aeration tank of dyeing wastewater is activated sludge method, although the hydraulic residence time is 15.3 hours and the treatment time in the above table is 6 hours, the treatment effect of total phosphorus (TP) is excellent and the water quality of the remaining 6 items is Almost similar values were shown.

In other words, it was found that the removal efficiency of harmful components was excellent enough that the treated water quality was similar even at the residence time of about 2/5.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

As mentioned above, the present invention shows that the removal efficiency is excellent for BOD, COD, and SS as well as chromaticity, which is a problem in dyeing wastewater. there was.

In addition, since the main component of the carrier is industrial waste, it is possible to maximize the utilization of resources and to maintain a comfortable living environment, and to produce the carrier at low cost by preparing the carrier at low temperature, not at high temperature.

Claims (11)

Blast furnace cement 30-50wt%, coal ash 20-40wt%, waste carbon 10-20wt%, kaolin tailings 5-15wt%, zeolite tailings 5-15wt%, waste organic foam powder 1-2.5wt% and fluidizing agent 1.3-2.3 A low temperature fired carrier for wastewater treatment utilizing wastes, characterized in that it comprises wt%. The method of claim 1, The blast furnace cement is a low-temperature fired carrier for wastewater treatment utilizing waste, characterized in that the blast furnace slag powder is contained 40wt% or more. The method of claim 1, The coal ash refers to the fly ash discharged as a by-product from the coal-fired power plant using anthracite coal or bituminous coal, and low-temperature baking carrier for wastewater treatment using waste, characterized in that it contains unburned carbon powder. The method of claim 1, The waste carbon is any low temperature calcined carrier for wastewater treatment utilizing wastes, characterized in that any one selected from the group consisting of coals that have been left or discarded in coal mines or waste activated carbons recycled after primary use due to low heat. . The method of claim 1, The kaolin tailings are low-temperature calcined carrier for wastewater treatment using waste, characterized in that the kaolin is not used because of its low grade. The method of claim 1, The zeolite tailings is a low-temperature fired carrier for wastewater treatment utilizing waste, characterized in that the natural zeolite is not used because of its low grade. The method of claim 1, The waste organic foam powder is any one selected from the group consisting of pulverizing the polyurethane foam, phenol foam and polystyrene foam, which are discarded after the first use to about 2 mm or less. Low temperature fired carrier for treatment. The method of claim 1, The fluidizing agent is a fluidizing agent for hydraulic cement, a low temperature calcined carrier for waste water treatment utilizing waste, characterized in that any one selected from the group consisting of a fluidizing agent containing a foaming agent or a non-containing fluidizing agent. In the method for producing an inorganic carrier, Firstly mixing the blast furnace cement, coal ash, waste carbons, kaolin and zeolite tailings and waste organic foam powder: Mixing the second mixture by adding water containing a fluidizing agent to the first mixture; Shaping the secondary mixture; Method for producing a low-temperature calcined carrier for waste water treatment using waste, characterized in that it comprises the step of curing the molded composition. The method of claim 9, The molding step is a method for producing a low temperature calcined carrier for wastewater treatment using waste, characterized in that the production of spherical (3 ~ 30 Φ mm) using an extrusion molding machine at a pressure of 1 ~ 20 kgf / ㎠. The method of claim 9, The curing step is a step of low temperature firing at 170 to 200 ℃ after being left for 20 days or more in a shaded place of 10-25 ℃, 8 to 15 at a pressure of 8.1 to 15.9 kgf / ㎠ after low temperature baking at 170 to 200 ℃ Method for producing a low-temperature calcined carrier for wastewater treatment using waste, characterized in that the one selected from the steps of time hydrothermal treatment.