KR101116122B1 - The Ceramic filter media for the removal of nonpoint pollution source - Google Patents

Abstract

The present invention relates to a "ceramic filter medium for removing non-point source," and relates to a new filter medium capable of effectively removing various non-point source, as well as being able to use semi-permanently for a long time.
The mixed composition for the preparation of the "non-point source removal ceramic filter medium" according to the present invention is composed of "barite, cryolite, dolomite, silvite" as a main component.
"Non-point pollutant removal ceramic filter medium" according to the present invention has the advantage that the removal ability of various non-point sources is superior to any conventional filter, as well as mass production at a low price.
[Index]
Nonpoint source, filter media

Description

Ceramic filter media for removing non-point pollution sources and manufacturing method of ceramic balls using the same {“The Ceramic filter media” for the removal of nonpoint pollution source}

The present invention relates to a 'ceramic filter medium for removing non-point source', and to a new technology that not only effectively removes a non-point source, but also extends the life of the filter medium, and has the advantage of being able to mass-produce at a low price.

Nonpoint source refers to a source that emits unspecified water pollutants from an unspecified place as a city, road, farmland, mountainous area, construction site, etc. (Article 2, Article 2 of the Act on the Conservation of Water Quality and Aquatic Ecosystems). number)

Point pollutants are easy to collect due to the clear outflow path of pollutants, and can be predicted annually due to the relatively small seasonal effects, making it easier to design and maintain / manage treatment facilities such as conduits and treatment plants. An example of a point source is an example of a wastewater discharge facility in factories and workplaces under the Act on Water Quality and Ecosystem Conservation.

On the other hand, non-point sources are difficult to collect because the flow and discharge paths of pollutants are not clearly distinguished, and the design and maintenance of treatment facilities is difficult because the amount / emissions are highly dependent on weather conditions such as precipitation. .

Examples of nonpoint source include: fertilizers and pesticides that are not absorbed by crops, remaining in agricultural land, manure that is grazed on pasture, untreated livestock waste from livestock farms, air pollutants mixed with rainwater, sediments on road surfaces, This includes sewage / sewage and rainwater mixed in the sewage pipe that flows into the river beyond the design amount during rainfall.

Point sources and nonpoint sources are relative concepts. For example, factories that discharge plant wastewater that are collected through conduits and treated through water pollution prevention facilities are point sources, while they are introduced into rivers without any other treatment. Factory sites such as yards that discharge rainfall runoff can be said to belong to nonpoint source.

An example of a nonpoint source is as follows.

end. Sediment

In soil, nutrients, metals, hydrocarbons, and other contaminants are adsorbed and moved together. Soils are a major contaminant of rainfall runoff and cause a fatal effect on aquatic organisms' photosynthesis, respiration, growth and reproduction.

I. Nutrients

Nutrients such as nitrogen and phosphorus are used as fertilizers, which are often leaked by rainwater and promote algae growth, thereby worsening the quality of rivers and lakes. It flows out of lawns, farmland, urban roads and sewers of houses and golf courses and flows into rivers.

All. Bacteria & Viruses

It is frequently detected in animal wastes and overflows from sewers. In the United States, high concentrations of bacteria and viruses in rainfall runoff have caused streams and lakes to be contaminated, leading to closure.

la. Oil & Grease

Oil and grease can be fatal to aquatic life, even in small amounts. Pollution can occur during accidents such as leaks, vehicle rollovers, vehicle cleaning, and waste dumping.

hemp. Metals

Heavy metals such as lead, zinc, cadmium, copper, and nickel are commonly detected in rainfall runoff in urban areas, and over 50% of the total amount of metals flowing into rivers is discharged through soil.

Metallic substances are fatal to the aquatic ecosystem and require special management because of the potential for bioaccumulation and drinking water contamination.

bar. Organics

It flows from a wide range of places such as fields, rice fields, forests, and residential areas, and especially in conjoined conduits, organic materials contained in sewage and sewage, which usually flow through sewage pipes at a low flow rate, are deposited at the bottom of the conduit, and are discharged at the time of rainfall. .

In industrial areas, artificial organic compounds such as adhesives, cleaners, and solvents are widely used, resulting in improper storage and disposal.

four. Pesticides

Insecticides such as herbicides, pesticides, and antifungal agents can accumulate in aquatic organisms such as plankton, causing bioconcentration through the food web, which can be fatal to fish and algae.

Ah. Gross Pollutants

Garbage, residues, suspended solids, etc. generated at construction sites and workplaces may include heavy metals, insecticides, bacteria, and the like. Remnants of fallen leaves or grass, animal waste, and dumped waste are the carriers of bacteria, viruses, etc. to rivers and lakes, and can also cause fish death by reducing dissolved oxygen.

As urban development and industrialization progress, land development is accelerated, and the area of impermeable layers such as land, roads, and parking lots is increasing, so the impact of water quality on rivers and lakes caused by nonpoint sources is increasing. Floating substances such as soil and sand, nutrients such as nitrogen and phosphorus, and high concentrations of heavy metals are difficult to collect and treat due to rainfall from nonpoint sources, and contaminate the water quality immediately by entering the river without special treatment. Aquatic ecosystems are disturbed by mass deaths and destruction of benthic habitats. In addition, an increase in impermeable layers due to land development increases the amount of rainwater that is not absorbed or evaporated into the soil during rainfall, increasing the risk of flooding and reducing groundwater replenishment, which in turn causes dryness of rivers. It becomes a factor.

Existing non-point source reduction methods are divided into natural facilities and device-type facilities.

Natural facilities are divided into "storage facilities, artificial wetlands, infiltration facilities, and vegetation facilities".

Apparatus-type facilities are divided into “filtration facilities, vortex-type facilities, screen-type facilities, flocculation and sedimentation treatment facilities, and biological treatment facilities”.

The natural facilities are as follows.

Reservoir (Reservoir) is a facility that stores non-point pollutants by storing rainfall runoff and sedimentation. There are natural reservoir and underground reservoir.

Artificial wetland is a facility that reduces non-point pollutants by artificially improving the purification capacity of natural wetlands such as sedimentation, filtration, adsorption, microbial decomposition, and purification by vegetation plants.

Infiltration facility is a facility to reduce non-point pollutants according to filtration and adsorption of soil by infiltrating rainfall runoff underground, including perforated pavement, permeable pavement, infiltration tank, infiltration reservoir, permeation ditch.

Vegetation-type facilities mean facilities that function as greenery while providing non-point pollutants by filtration and adsorption of soil and adsorption of plants, and provide animal and plant habitat spaces. have.

Device type facilities are as follows.

The filtration facility is a facility to reduce non-point pollutants by collecting rainfall runoff in a collecting tank and then filtering it through filter media such as sand and soil.

Vortex type facility is a facility to reduce non-point pollutants by forming vortices by moving the central rotary to float floating materials such as oil and grease to the top, and sediment sediment and separation to the bottom.

Screen-type facility is a facility that removes relatively large floats and garbage by filtration and separation of the network and is mainly used for pretreatment.

The advantages and disadvantages of nonpoint source reduction facilities are summarized in the table below.

A filter media is a porous medium used for filtration and varies depending on the characteristics of the target material. Also called a filter or filter. Particle or powder media such as sand, gravel, garnet, activated carbon, diatomaceous earth, and anthracite are used for large-scale water treatment of water and sewage. Sand or anthracite is used in double filtration, while sand, garnet, and anthracite are used in triple filtration. A typical filtration method using sand is slow filtration of a water treatment plant. Fiber types include filter cloth, paper, felt and sponge, etc., but the price is relatively cheap and the dust collecting effect is good, so the application range is wide. The material of the filter cloth is various kinds by natural fiber and artificial fiber. Carbon, metal, plastic, etc. are used as the porous material, and high mechanical strength is used for industrial high pressure filter. Carbon is especially suitable for filters that must withstand corrosion well. Separation membrane is used for the membrane separation method which is a desalination technique of industrial water. This medium, called osmotic or semipermeable membrane, is a solid or liquid membrane made of cellulose acetate. Materials to be filtered include dyeing and dye wastewater, heavy water, sewage, heavy metal wastewater, petrochemical wastewater and landfill leachate. The properties of these media should be ① the size of micropore is appropriate ② the adhesion is good ③ the hole is not clogged ④ resistant to pressure and friction ⑤ corrosion resistance is good ⑥ the filter resistance is small and ⑦ low price.

Ceramics refers to products made by heat-treating inorganic materials other than metals. Ceramic products made of clay or silica sand, and products made by heat treatment using inorganic materials other than metal. Pottery, glass, cement, brick, refractory, abrasives, enamel, tiles, etc. Ceramic products are excellent in heat resistance, rust and electricity. Nowadays, they are also used as refractory and semiconductors that withstand very high temperatures.

The ceramic filter medium for removing non-point source according to the present invention is not only to effectively remove various non-point source, but also to extend the life of the filter medium and to provide a mixed composition capable of mass production at a low price.

The present invention for achieving the above object is 8-12 wt% of barite, 15-25 wt% of cryolite, 20-30 wt% of dolomite, 40-50 wt% of Silvite A ceramic filter medium for removing non-point source, characterized in that it is configured to have a composition ratio;
A ceramic filter media mixture for removing non-point sources consisting of 8-12 wt% barite, 15-25 wt% cryolite, 20-30 wt% dolomite, and 40-50 wt% Silvite After micronization to 2000-3000 mesh, water is added to the finely divided nonpoint source removal ceramic filter media mixture and stirred for 10 to 15 minutes, and the stirred non-point source removal ceramic filter media mixture is processed into spherical balls. It is to provide a ceramic ball production method characterized in that the first firing in a kiln of 1500 ℃ ~ 2000 ℃, and then firing in a kiln of 2500 ℃ ~ 3000 ℃ to produce a ceramic ball.

The present invention relates to a new non-point source removal filter material that can effectively remove the non-point source that is the main factor of various water pollution, increase the life of the filter medium and furthermore, can be manufactured at low cost.

Although the invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that modifications and variations can be made within the spirit and scope of the invention, and such variations or modifications are within the scope of the appended claims. will be.

"Ceramic filter medium for non-point source removal" according to the present invention is composed of a step of mixing the filtration material, firing the mixed material, ceramic coating the spherical ball produced by firing.

Looking at each step in detail.

There is a need to prepare filtration materials for effectively removing nonpoint sources. The filter medium is composed mainly of "barite, cryolite, dolomite and silbite".

Barite is a mineral belonging to a tetragonal system with a crystal structure like olivine, and its chemical composition is BaSO4. Usually, it shows a ridge-shaped crystal, and in addition, it forms a quadrilateral plate, columnar shape, and lobe shape, and sometimes a massive shape is formed. Sometimes. Cleavage is complete on the base and main surface. The monocyte is not flat. Hardness 2.5-3.5, specific gravity 4.3-4.7. Many are colorless, transparent or white translucent, and may be yellow, red, blue, or brown. There is glass gloss, pearly gloss on the split surface parallel to the base. It is commonly produced as a mineral vein mineral of various hydrothermal deposits. It is important as a raw material for white pigments and paints, and is used for papermaking, textile manufacturing, and medical care.

Cryolite is a mineral belonging to the monoclinic system. Used as a flux in aluminum smelting and produced in large quantities in Greenland. The chemical component is Na 3 AlF 6. It mainly forms aggregates of aggregates or granules and rarely exhibits crystal forms. There are no splits, but there are ten in three directions, which cause them to break into cube-like shapes. Hardness 2.5 and specific gravity 2.97. Snow white and slightly transparent, sometimes reddish brown. There is glass gloss, and streak color is white. Dissolves in sulfuric acid to generate hydrogen fluoride. When heated, it is easy to melt and the flame turns yellow. Used as a flux for smelting aluminum.

Dolomite is a trigonal mineral, formed by the dolomite of calcite, similar to calcite. Also known as dolomite (白雲石) or kaolinite (苦 灰石). The chemical component is CaMg (CO3) 2. Lime carbonate and magnesium carbonate form 1: 1 bicarbonate. However, part of magnesium is often replaced by iron or manganese. It shows a rhombus crystal and the crystal plane is somewhat curved. It often forms a saddle or rose bud. In some cases, they are formed into granules or aggregates of dense matter. The firmness is 3.5-4 and the specific gravity is 2.8-2.9. There is a complete split in the direction of the rhombus. White, gray, pink, yellow, brown, etc., sometimes green. It is transparent or translucent and has a glass luster, and the crystal sometimes has a pearl luster. Similar to calcite, but slightly heavier, the degree of foaming by dilute hydrochloric acid is weaker than calcite. Some of the calcite constituting the limestone is dolomite, but only a part is dolomite. The dolomite of part of the limestone is called dolomite limestone.

Sylvite is a glassy white or colorless equiaxed mineral. The chemical formula is KCl and has a molecular weight of 74.551. The crystal system is a cubic system. Appearances appear as cubic crystals, octahedral and cubic-octahedral, masses, and the like. Colors vary from white, gray, blue, red, and transparent, with a glass gloss.

The above composition ratio is the result of finding the most suitable golden ratio through the experiment.

When the mixed composition produced and manufactured is processed in the form of a spherical ball, it is possible to effectively remove various nonpoint sources.

The firing step of the mixed material is as follows.
A ceramic filter media mixture for removing non-point sources consisting of 8-12 wt% barite, 15-25 wt% cryolite, 20-30 wt% dolomite, and 40-50 wt% Silvite Differentiate to 2000 ~ 3000 mesh.
Water is added to the finely divided nonpoint source ceramic filter media mixture and stirred for 10 to 15 minutes.
The stirred non-point source removal ceramic filter media mixture is processed into a spherical ball, followed by primary firing in a baking furnace at 1500 ° C to 2000 ° C, and then firing at a baking furnace at 2500 ° C to 3000 ° C.
The reason for dividing the firing into the primary and secondary is to prevent the disappearance of the rapid heating.

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Looking at the step of ceramic coating the spherical ball produced by firing as follows.

Thermal spray coating, developed around 1910, is a cold coating technology that can be applied to a base material without thermal deformation. The coating material in the form of powder, wire, or rod is transferred into a flame, electric arc, or plasma flame. It is a surface treatment technology that forms a coating by spraying and colliding with a base material at high speed after the transfer melting.

Plasma spraying, a kind of thermal spray coating, is a technique developed by transforming plasma welding (PTA) in the special chamber where electric arc energy is composed of nozzle and electrode, and it can be used for the inert gas such as argon, hydrogen, nitrogen or helium. Ionization forms a plasma consisting of electrons, neutrons, and both, and the high temperature, high heat, and high velocity plasma flame is ejected out of the chamber while the ionized plasma recombines. The powder-like material is transferred to the flame salt at a uniform speed and melt-sprayed into the base material to form a high density coating film. Plasma fusion coating method is a high density coating is possible because the gas is compressed in a limited chamber, the stability of the arc is good, and heat energy can be concentrated. Since the flame speed is high at 650 m / sec, a coating having few pores and excellent adhesion can be obtained. Also very little oxidation of the coating.

Coating method of the filter medium for removing the non-point source according to the present invention is to use the plasma melt coating method. The coating ceramic is a 1: 1 mixture of zirconia and alumina to surface-coating the spherical ball prepared by the above method by plasma thermal coating.

Zirconium is a silvery or grayish white shiny metal and belongs to the hexagonal system. Amorphous is black powder, and powder has a low flash point and is easy to explode when mixed with an oxidizing agent. It is easy to oxidize at normal temperature, but it is easy to become zirconium oxide at high temperature. Insoluble in acids and alkalis, soluble only in aqua regia and hydrofluoric acid. Its properties are similar to titanium, and its separation from hafnium is difficult, especially because its chemical properties resemble hafnium. The melting point is higher than that of titanium, but the heat resistance is weaker than that of titanium, and the tensile strength is lowered above 400 ° C. The absorption cross-sectional area of the thermal neutron is the smallest among the metal materials, and the corrosion resistance is very good. However, since it is necessary to contain no hafnium, a chelating compound is made of an acetylacetone derivative, the hafnium is separated, and then metallurgical purification. In addition, it is used for getters of vacuum tubes, flashlights for photographs, and the like, and for deoxidation and desulfurization in the steel industry, and for acid-resistant materials as alloys. Oxides are used as white pigments and refractory materials.

Zirconia (zirconia) is a type of zirconium that refers to all over zirconium oxide. Zirconium oxide, white crystals. The chemical formula is ZrO2. The molecular weight is 123.22 and the melting point is about 2,700 ° C. It is rare mineral in monoclinic system. The refractive index is large and the melting point is high, so the corrosion resistance is large. It is insoluble in water and soluble in sulfuric acid and hydrofluoric acid. It is an important raw material for ceramics, and it is also used as a substitute for teeth due to its high strength and aesthetics among the ceramic materials used in dentistry. Since it withstands rapid temperature changes, it is also used in appliances (eg crucibles) of rapid heat and quenching.

Alumina is also called aluminum oxide. Alumina is a compound of aluminum and oxygen, and the chemical formula is Al2O3. The molecular weight is 101.96. Naturally, there are ruby and sapphire, which are produced by corundum, a crystal mineral, and colored by pure corundum. It is known to have various forms, and α-aluminum oxide produced by heating aluminum hydroxide to 300 ° C. or lower is the purest and most stable form. (alpha)-aluminum oxide is mainly a raw material of aluminum, and the melt | dissolved crystal | crystallization is generally hardened (Moss-harden 9), refractive index 1.76-1.77, and is used also as an artificial gemstone | polishing agent. As crystals develop, they are less soluble in acids and alkalis, so they are sintered to form alumina porcelain.

The coating method of the filter medium for removing the non-point source according to the present invention is a ceramic coating is used by using a mixture of zirconia and alumina in a 1: 1, when the filter medium is subjected to the surface coating treatment by plasma melt coating method, the filter medium Can be extended semi-permanently.

The filter medium for removing non-point source according to the present invention effectively removes various contaminants of the non-point source and has a long life of the filter medium, thereby reducing the burden of replacing the filter medium, and securing a merit that can be manufactured at a lower cost.

Claims (5)

Boiling point comprising 8-12 wt% of barite, 15-25 wt% of cryolite, 20-30 wt% of dolomite, and 40-50 wt% of Silvite. Ceramic filter media for pollutant removal. A ceramic filter media mixture for removing non-point sources consisting of 8-12 wt% barite, 15-25 wt% cryolite, 20-30 wt% dolomite, and 40-50 wt% Silvite After micronization to 2000-3000 mesh, water is added to the finely divided nonpoint source removal ceramic filter media mixture and stirred for 10 to 15 minutes, and the stirred non-point source removal ceramic filter media mixture is processed into spherical balls. A primary firing in a kiln at 1500 ° C. to 2000 ° C., followed by firing in a kiln at 2500 ° C. to 3000 ° C. to produce a ceramic ball.
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