KR100883436B1 - Non-point pollution source treatment apparatus using biological media and treatment method thereof - Google Patents

Abstract

A nonpoint pollution processing unit using a bio-filter is provided to make a pH condition that microorganisms smoothly cause denitrification and to improve efficiency of water treatment by supplying continuously alkalinity in a carrier containing pearlite and calcium hydrooxide causing alkalinity. A nonpoint pollution processing unit using a bio-filter contains a precipitation part(5) separating foreign materials in rain flown in by difference of specific gravity, a first bio-filter processing unit(40) removing organic compound in the rain flown out from the precipitation part and a second bio-filter processing unit(50) removing nitrogen and phosphorus in the rain flown out from the first bio-filter processing unit. The precipitation part comprises a first settling tank(10) and a second settling tank(30). The first settling tank includes a compartment diaphragm, an influx unit formed into an inclined plate so that the rain is flown into a rear space part, a screen network installed in an opened top part of the first settling tank and connected to the influx unit.

Description

Non-point pollution source treatment apparatus using biological media and treatment method

The present invention relates to a non-point source treatment apparatus and treatment method using a biofilm, the present invention relates to a non-point source of residual soil, organic matter, heavy metals, etc. occurring during development or roadside construction or construction, and a large amount of boiling point after completion of the development project The present invention relates to a non-point pollution source treatment apparatus and treatment method for reducing the pollution source.

At present, global water shortage is a major issue in many countries, and Korea has also been unable to neglect it. In order to solve this water shortage, we have found ways to efficiently manage, secure and utilize water in various ways. There is a situation.

Therefore, in order to solve the water shortage phenomenon, various methods for efficiently using rainwater falling naturally have been researched and developed.

However, such rainwater is exposed to various pollutants in the air and falls down, and the groundwater is permeated into rivers with various pollutants on the surface of the earth, thus removing the pollutants contained in the rainwater and improving the water quality of the streams. In order to achieve this, there is a need for an excellent purification facility.

In general, pollutants include point pollutants and agricultural land, grassland, forest land, construction sites, mines, logging sites, waste disposal plants, wastes, etc., which are discharged from a defined and limited point source, such as domestic rainwater, industrial wastewater, and livestock wastewater. Discharge areas such as landfills, urban areas, roads and industrial sites can be divided into nonpoint pollutants emitted from a wide range of nonpoint sources.

Contaminants emitted from the pollutant as described above are distributed in a variety of forms such as heavy metals, pathogenic microorganisms, organic compounds, radioactive materials, toxic substances and other salts. These pollutants are usually swept away in rainy weather and flow into public waters such as rivers, bays and lakes, or underground waters, causing water pollution, and eventually destroying ecosystems. It causes great harm.

If no action is taken on stormwater treatment facilities around non-point sources, or only the various rocks, oils, and heavy metals provided by nonpoint sources are removed, untreated organic matter flows into the rivers, acting as a major source of pollution.

Therefore, it is required to install a prevention facility for treating nonpoint source. During the development project, nonpoint source planning aims to minimize the area and duration of exposure to rainfall and to minimize surface disturbances in areas and slopes where nonpoint pollutants are likely to leak. In addition, the backfilling soil for use in the soil and aggregate collection process stored on site is covered with a cover to prevent exposure to rainfall, and a drainage drainage is installed so that the sludge leaked during rainfall is introduced into a non-point source facility.

In the case of point pollutants among pollutants, a separate purification device or wastewater treatment facility is installed in homes, factories, and livestock farms, and some of the pollutants are purified. However, most of them remain on the earth's surface and flow into rainwater, public waters such as rivers, bays, lakes, and groundwater, causing rainwater pollution.

Conventional techniques for treating such non-point sources include natural facilities such as reservoirs, artificial wetlands, infiltration facilities, vegetation-type facilities, filtration-type facilities, vortex-type facilities, and screen-type facilities.

In the case of storage tanks, heavy rains in summer require large-scale land or equipment, and if untreated water is kept, pests such as flies and mosquitoes are generated, which causes hygiene problems. Infiltration type causes soil clogging due to inflow of soil or floating material during construction, and vegetation type requires more than a certain amount of land and conditions for maintaining vegetation, but it is difficult in case of having four seasons like Korea. There is this.

Recently, since sewage pipes are classified pipes, treatment for non-point pollutants spilled in rainwater is required, and various technologies have been developed for methods and devices for removing non-point pollutants generated during development and rainwater.

Various techniques are known, such as the initial excellent purification treatment apparatus of Korean Patent No. 0779513 and the non-point contaminant purification apparatus of the initial effluent of No. 561092, but most of them are limited to physical treatment methods such as precipitation and filtration. There is a problem that can not be removed.

The present invention has been made to improve the above problems, the main technique is to physically remove the precipitated material that occurs when the conventional apparatus for treating non-point source is excellent, but in the present invention rockfall or sand, etc. It provides a non-point source treatment apparatus and treatment method which precipitates solids and removes colloidal material including organics by biological membrane method using gravel layer and removes nitrogen or phosphorus from biological process consisting of anoxic and aerobic tanks. Its purpose is to.

Non-point source treatment apparatus of the present invention for achieving the above object comprises a sedimentation unit for separating the foreign matter in the incoming sewage by the difference in specific gravity; A first biofilm treatment unit for removing organic substances in the sewage flowing out of the precipitation unit; And a second biofilm treatment unit for removing nitrogen and phosphorus from the effluent flowing out of the first biofilm treatment unit.

The sedimentation unit is characterized in that it comprises a first sedimentation tank for separating rock or sediment contained in the sewage by screening, and a second sedimentation tank for sedimenting the remaining solids contained in the sewage passed through the first sedimentation tank.

The first biofilm treatment unit may include a contact tank and a gravel layer formed under the contact tank and having microorganisms attached to a surface thereof.

The second biofilm treatment unit is filled with a first carrier in which nitrifying microorganisms are fixed, and aeration tank for nitrifying ammonia nitrogen and organic nitrogen in rainwater, and rainwater flows from the aeration tank as overflow, thereby fixing sulfur oxide microorganisms. And an anoxic tank filled with a second carrier to denitrify the nitrate nitrogen, and a discharge tank for pouring rainwater into the overflow from the anoxic tank and separating and discharging the treated water and sludge.

The first carrier is characterized in that formed by mixing pearlite, hydrated lime and water.

The second carrier is characterized in that formed by mixing sulfur, pearlite, slaked lime and water.

And the non-point source treatment method of the present invention for achieving the above object is a precipitation step of separating the foreign matter in the incoming sewage by the difference in specific gravity; An organic material removing step of removing the organic material contained in the sewage after the precipitation step is completed; A nitrification step of nitrifying the ammonia nitrogen and the organic nitrogen in the sewage by the first carrier to which the nitrifying microorganism is fixed after completion of the organic material removing step; And a denitrification step of denitrifying the nitrate nitrogen in the sewage by the second carrier to which the sulfur oxidizing microorganism is immobilized after the nitrification step is completed.

The second carrier is characterized in that the molded body kneaded by mixing sulfur, pearlite, hydrated lime and water, dried, immersed in calcium hydroxide solution, washed and dried.

As described above, according to the non-point source treatment apparatus and processing method of the present invention, non-point pollution is generated by purifying non-point pollutants such as organic matter, nitrogen or phosphorus, as well as falling rocks, gravel and suspended solids generated from nonpoint sources. By preventing water pollution due to materials, it is possible to reduce the load of organic materials into the water purification plant.

Particularly, in the present invention, microorganisms are smoothly denitrified by continuously supplying alkalinity from a carrier itself containing perlite and slaked lime, which are alkalinity-causing substances, without adding a carbon source and an alkali source to drugs, shells, and limestones that supply alkalinity. It creates a pH condition that can cause an increase in water treatment efficiency.

It also has excellent removal performance of dissolved dissolved substances in influent, minimizes the secondary burden caused by biological treatment of pollutants and minimizes the environmental burden. It offers the advantage of semi-permanent treatment technology without the need for replacement.

In addition, the biological reaction tank is operated by the water level control, so when there is no inflow water, the operation is stopped and the electricity consumption is reduced.

Hereinafter, a non-point source treatment apparatus and a treatment method according to a preferred embodiment of the present invention with reference to the accompanying drawings will be described in detail.

1 is a perspective view showing a non-point source processing apparatus according to an embodiment of the present invention, Figure 2 is a cross-sectional view showing the interior of the non-point source processing apparatus of FIG.

The present invention is a non-point source treatment apparatus that combines precipitation and biological treatment methods by solid-liquid separation as a non-continuous reactor for treating non-point sources stored in roadsides, forests, and individual livestock farms during business development or stormwater.

The present invention provides roadside construction or construction, construction of industrial sites and industrial complexes, energy development, construction of airports, reclamation and reclamation of shared waters, development of tourism complexes, development of mountainous areas, installation of military defense facilities, and installation of soil sand gravel It can be applied to the non-point source generated during the development project such as collection and the non-point source generated in the non-point pollution factory after the construction of the development project is completed.

1 and 2, the non-point source treatment apparatus of the present invention has a precipitating unit 5, a first biofilm processing unit 40, and a second biofilm processing unit 50.

The sedimentation part 5 separates by the difference of specific gravity from the solid particle | grains which are comparatively large particle containing rockfall or the big contaminant contained in rainwater to the initial rainwater initial rainfall during rainfall, and the comparatively small particle solid object such as earth and sand. The first biofilm processing unit 40 removes the organic matter contained in the rainwater that has passed through the precipitation unit 5 by using the microbial film attached to the gravel 43, and the second biofilm processing unit 50 is the first biofilm processing unit 40. Nitrogen or phosphorus not removed from the biological process is removed.

The sedimentation part 5 is the earth sediment contained in the rainwater which passed the 1st sedimentation tank 10 and the 1st sedimentation tank 10 for isolate | separating the solid particle which is comparatively large particle containing rockfall or a major contaminant contained in rainwater. And a second settling tank 30 for precipitating solid foreign matter having a relatively small particle size.

The first settling tank 10 is formed in a rectangular cylindrical shape with a hollow inside and an open top. The first settling tank 10 has a structure separated into a front space 23 and a rear space 25 by a partition plate 18 partitioning across the inner space. In addition, an upper portion of the first settling tank 10 in which the rear space portion 25 is located is a screen for separating the inflow portion 11 formed by the inclined plate so that the rainwater flows in, and the rockfall in the rainwater flowing through the inflow portion 11. The net 13 is installed to be inclined.

The front space 23 is a rockfall 27 filtered by the screen net 13, relatively large gravel and the like is rolled down and stored along the screen net (13). In this case, most rainwater flows into the rear space portion 25, but in case the rainwater flows into the front space portion 23, the rain space is filled in the front space portion 23. A wall hole 19 may be formed in the partition wall 18 so as to flow in the wall.

Rainwater flowing through the screen net 13 is introduced into the rear space 25, and the major contaminants and solids having a small particle size included in the rainwater are separated from the water by the difference in specific gravity and settle on the bottom. . In addition, suspended solids such as dust and oil, which are foreign substances having a smaller specific gravity than water, rise above the water surface. In this case, an adsorption cloth (not shown) is installed on the upper side of the rear space of the first settling tank to remove suspended substances including oil and the like.

Rainwater flows into the second settling tank 30 through the first outlet pipe 21 formed on the upper sidewall of the first settling tank 10.

The second settling tank 30 is formed in a rectangular cylindrical shape having an upper portion and having a predetermined size space therein. In this case, the second settling tank 30 is preferably formed so that the upper end is somewhat lower than the first outlet pipe 21.

Rainwater flowing into the second settling tank 30 precipitates the foreign matter 39 having relatively small particles such as soil, sand, and heavy metal not removed from the first settling tank 10 to the bottom surface. Therefore, the present invention effectively separates the foreign matter according to specific gravity by configuring two sedimentation tanks that are continuously processed.

Rainwater that has passed through the second settling tank 30 is introduced into the first biofilm processing unit 40 through the second outlet pipe 35 formed on the upper sidewall of the second settling tank 30.

The first biofilm processing unit 40 includes a contacting tank 41 and a gravel layer formed of a plurality of gravel 43 formed under the contacting tank 41 and having microorganisms attached to the surface thereof. Preferably, the gravel constituting the gravel layer uses a size of 20 to 200mm. This gravel layer may additionally have a filtering function. In particular, preferably utilizing the gravel stored in the front space portion 23 of the first precipitation tank.

The contact tank 41 has a rectangular cylindrical shape with an upper opening, and is formed such that its upper end is lower than the second outlet pipe 35 of the second settling tank. In the first biofilm processing unit 40, rainwater flowing out through the second outflow pipe 35 falls naturally due to gravity and flows into the contact tank 41, and the microbial membrane attached to the gravel causes BOD ₅ , COD, TSS, Organic substances such as TN and TP are decomposed. In this case, microorganisms such as Vorticela, Aspidisca, Rotaria, Euplotes, Amphileptus, etc. may be used.

Rainwater that has passed through the first biofilm processor 40 flows out to the second biofilm processor 50. The second biofilm treatment unit stops operation when the water level is below a certain level because there is no inflow water, and microorganisms have a rest period due to assetization and activity deterioration, and microorganisms can remove organic matters when rainwater, including pollutants, is introduced again. Activity is activated.

The second biofilm treatment unit 50 is formed in a rectangular cylindrical shape installed on the side of the contact tank 41 and has a predetermined size space therein. The inner space is divided into an aeration tank 60, an oxygen-free tank 70, and an exhaust tank 80 by two first and second partition walls 53 and 55 extending vertically from the bottom. At this time, the upper ends of the partitions 53 and 55 are formed to be spaced apart from the upper plate of the second biofilm treatment unit by a predetermined distance.

Rainwater flows into the aeration tank 60 through the third outlet pipe 45 installed below the side wall of the contact tank 41. And the lower part of the aeration tank 60 is provided with an diffuser 61 for aeration of air in rainwater. The diffuser 61 is connected to the air supply line 69 extending to the outside, and although not shown, the air supply line 69 is supplied with air of a constant pressure through a blower. And on the air supply line 69 may be installed a flow meter and a valve for adjusting the amount of air.

Above the diffuser 61, the upper porous panel 63 and the lower porous panel 65 are installed to be spaced apart by a predetermined distance vertically across the aeration tank 60 horizontally. A plurality of through holes are formed in the upper and porous panels 63 and 65 to allow rainwater to pass through. The first carrier 67 is filled between the upper and lower porous panels 63 and 65. In this case, the first carrier is filled to occupy 5 to 30% of the total volume of the aeration tank depending on the conditions of the installation site.

Preferably, the first carrier 67 is formed by mixing pearlite, slaked lime and water. The first carrier 67 is mixed with 80 to 120 parts by weight of calcined lime and 200 to 400 parts by weight of water based on 100 parts by weight of perlite, and then stirred by mixing 200 to 400 parts by weight of water in the mixture. The dough is formed in a dumpling or rod form, dried at room temperature, washed several times with distilled water, dried in a dryer at 50 ° C. for 15 hours, and fixed with nitric oxide microorganisms. In addition, the first carrier may of course use a conventional carrier to which nitrifying microorganisms are fixed.

As nitrification microorganisms, nitrosomonas and nitrobacter may be used, and the air is aerated to keep the temperature at 15 to 20 ° C. and dissolved oxygen at 3 to 5 ppm.

In the aeration tank 60, the organic material of BOD and chemical oxygen demand (COD) as well as the organic material of BOD is maintained at 20 ppm or less so that nitrification microorganisms can proliferate, so that ammonia and organic nitrogen are nitric acid. Nitrify with nitrogen. In addition, the microorganism removes the phosphorus by causing excessive intake of phosphorus released under anaerobic conditions.

Rainwater that has passed through the aeration tank 60 flows into the anaerobic tank 70 by overflowing the upper end of the first partition 53.

The oxygen-free tank 70 is for denitrification by nitrogen gas by reducing nitrate nitrogen, and the second carrier 73 is filled in the oxygen-free tank.

The second carrier 73 is formed by mixing sulfur, pearlite, slaked lime and water. The second carrier 73 is 50 to 70 parts by weight perlite based on 100 parts by weight of sulfur, 30 to 50 parts by weight of slaked lime and then uniformly mixed by adding 200 to 400 parts by weight of water to the mixture and then kneaded or loaded It is prepared in the form of (rode), dried for at least 10 days, and then immersed in 0.3 M calcium hydroxide (Ca (OH) ₂ ) solution for about 4 hours.

By immersing in the calcium hydroxide solution as described above to remove the particles present in the form of powder between the pores of the carrier during the production of the carrier to increase the porosity and to sufficiently supplement the alkali to the pore surface formed inside the carrier. After immersion, washing several times with distilled water and drying in a dryer at 50 ° C. for 15 hours to fix sulfur oxidizing microorganisms.

Sulfur acts as a substrate for denitrification using sulfated microorganisms, and pearlite is sodium oxide (Na ₂ O), potassium oxide (K ₂ O), calcium oxide (CaO), iron oxide (Fe ₂ O ₃ ), phosphorus oxide ( P ₂ O ₅ ), magnesium oxide (MgO), nickel oxide (TiO ₂ ) and other components are present to play the essential nutrients for the growth of sulfur oxide microorganisms.

Slaked lime (Ca (OH) ₂ ) reacts with carbon dioxide to form calcium carbonate, as shown in the equation below.In autotrophic denitrification, alkalinity is reduced when nitric oxide (NO ₃ ^_ -N) is reduced and removed as the denitrification reaction proceeds. As it is consumed, it replenishes the alkalinity that is consumed, creating a pH condition that allows microorganisms to smoothly denitrify.

Ca (OH) ₂ + CO ₂ → CaCO ₃ + H ₂ O

^{_{CaCO 3 + H + → Ca 2}} + + HCO 3 -

As described above, in the present invention, a carrier, which is made of porous second carrier 25 using perlite (pellite) and calcined lime which is an alkalinity-causing substance, is added to the chemicals, shells, and limestones for supplying alkalinity without adding a carbon source and an alkali source. By continuously supplying alkalinity on its own, it creates a pH condition that microorganisms can smoothly denitrify, thereby improving water treatment efficiency.

Sulfur oxidation autotrophic microorganisms immobilized on the first and second carriers used in the present invention include Thiobacillus denier tripicus. denitrificans ) (ATCC 23644; DSM 12475; JCM3870; NCIMB 9548), and thiobacillus dinate tricuses cultured according to the culture information of S-8 MEDIUM FOR THIOBACILLI (Domestic Sewage, Taxonomy of anaerobic thiobacilli, J. Gen. Microbiol. 47; 17-23, 1967.This strain was wrongly guoted as NCIB 8327 in Bergey's Manual of Systenatric Bacteriology, vol. 3., p. 1855, 1989. Anaerobic). The second carrier is immersed in the thiobacilli denier tripicons culture and fixed at 30 ° C. As an example of immobilization, a carrier is mixed with a growth medium in an algebraic growth phase, incubated at 80 ° C. at 30 ° C., followed by a growth medium, centrifuged at 3600 rpm for 20 minutes, and again as a basic medium to fix microorganisms.

Under anoxic conditions, sulfur oxidative autotrophic microorganisms are NO using sulfur (S) and various reducing sulfur compounds (S ^2- , S, S ₂ O ₃ ^2- , S ₄ O ₆ ^2- , SO ₃ ^2- ). _A metabolic process of reducing energy by ₃ ^-- N to N ₂ gas to remove nitrogen in rainwater.

The reaction formula for autotrophic denitrification using sulfur is as follows.

^{_{NO 3 - + 1.1S + 0.76H 2}} O + 0.4CO 2 + 0.08NH 4 + → 0.08C 5 H 7 O 2 N + 0.8N 2 + 1.1SO 4 2 - + 1.28H +

As shown in the reaction scheme, autotrophic denitrification proceeds under anoxic conditions, nitrogen nitrate (NO ₃ ^-- N) is reduced in the carrier to generate nitrogen gas (N ₂ ), and sulfur (S) is oxidized to sulfate ions. do.

And the denitrified rainwater flows into the overflow tank 80 over the top of the second partition wall 55, the final treated water is discharged to the outside through the discharge pipe 83, sludge sludge outlet 85 Can be processed through

Hereinafter, a non-point source treatment method according to an embodiment of the present invention will be described.

Non-point source treatment method of the present invention comprises a precipitation step of separating the foreign matter in the rainwater greatly introduced by the difference in specific gravity, the organic material removal step, the nitrification step, and the denitrification step.

In the sedimentation step, foreign matters such as rockfall are separated and stored through the screen network, and the rainwater is separated by solid-liquid separation. The oil or suspended matter is then removed from the adsorption cloth to be precipitated.

The organic matter removing step removes the organic matter in the rainwater that has been treated in the precipitation step. In this process, organic substances such as BOD ₅ , COD, TSS, TN, and TP are decomposed by the microbial membrane attached to the gravel layer.

The nitrification step nitrifies the ammonia nitrogen and the organic nitrogen in rainwater by the first carrier to which the nitrifying microorganism is immobilized after the organic material removal step is completed.

The denitrification step is carried out by reducing the nitrate nitrogen in rainwater to nitrogen gas by the second carrier to which the sulfur oxidizing microorganism is fixed after completion of the nitrification step.

As described above, the present invention is the treatment of nonpoint pollutants in the initial rainfall runoff in the sewage treatment area, treatment of the overflow water in the combined sewage treatment area, removal of nonpoint pollutants introduced from the water supply source or dam, fire, water pollution in the workplace In case of an accident, it can be used as a non-point pollution reduction facility that has a combination of emergency storage tanks.In addition to the treatment of non-point pollutants generated in various development projects such as complex development, combined use with an excellent storage tank, and reuse of water in golf courses due to its excellent treatment efficiency It is a highly available technology that can be applied to the back.

As described above, the present invention has been described with reference to one embodiment, which is merely exemplary, and those skilled in the art will understand that various modifications and equivalent embodiments are possible therefrom.

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

1 is a perspective view showing a non-point source treatment apparatus according to an embodiment of the present invention,

FIG. 2 is a cross-sectional view illustrating an interior of the non-point source treatment apparatus of FIG. 1.

<Description of the symbols for the main parts of the drawings>

5: sedimentation section 10: first precipitation tank

30: second settling tank 40: first biofilm treatment unit

41: contact tank 43: gravel

50: second biofilm treatment unit 60: aeration tank

61: diffuser 67: first carrier

70: anoxic 73: second carrier

80: discharge tank

Claims (8)

Precipitating unit for separating the foreign matter in the rainwater introduced by the difference in specific gravity; A first biofilm treatment unit for removing organic matter in rainwater flowing out of the precipitation unit; And a second biofilm treatment portion for removing nitrogen and phosphorus from rainwater flowing out from the first biofilm treatment portion. The sedimentation unit is for separating rockfalls or contaminants contained in rainwater by screening and depositing a solid first sedimentation tank having a hollow inside and an open top and remaining solids contained in rainwater that has passed through the first sedimentation tank. 2 sedimentation tank, The first sedimentation tank is formed so as to cross the interior space partition partition partitioning into the front space portion and the rear space portion, the inlet portion formed by the inclined plate so that rainwater flows into the rear space portion, the inlet is connected to the rear space The rainwater flowing through the inlet portion is installed in the upper portion of the first settling tank located therein is introduced into the rear space portion and the screen net formed to be inclined downward so as to be stored in the front space to roll down the rockfall of the rain, and the rear space Non-point source treatment apparatus characterized in that it is provided on the upper part of the first settling tank located in the first discharge pipe is discharged to the second settling tank. delete The non-point source treatment apparatus of claim 1, wherein the first biofilm treatment unit includes a contact tank and a gravel layer formed under the contact tank and having microorganisms attached to a surface thereof. The method of claim 1, wherein the second biofilm treatment unit is filled with a first carrier to which the nitrifying microorganisms are immobilized to nitrify ammonia nitrogen and organic nitrogen in rainwater, and rainwater flows from the aeration tank as overflow and sulfur flows. And an anoxic tank filled with a second carrier having the oxidized microorganism fixed therein to denitrify the nitrate nitrogen, and a discharge tank for flowing rainwater from the anoxic tank as overflow and separating and discharging the treated water and sludge. Nonpoint source treatment device. The non-point source treatment apparatus of claim 4, wherein the first carrier is formed by mixing pearlite, slaked lime and water. The non-point source treatment apparatus according to claim 4, wherein the second carrier is formed by mixing sulfur, pearlite, slaked lime and water. A precipitation step of separating the foreign matter in the rainwater introduced by the difference in specific gravity in the precipitation section; An organic material removing step of removing the organic material contained in the rainwater after completion of the precipitation step; A nitrifying step of nitrifying the ammonia nitrogen and the organic nitrogen in rainwater by the first carrier to which the nitrifying microorganism is immobilized after the organic material removing step is completed; And a denitrification step of denitrifying nitrate nitrogen in rainwater by the second carrier to which the sulfur oxidizing microorganism is fixed after completion of the nitrification step. The sedimentation unit is for separating rockfalls or contaminants contained in rainwater by screening and depositing a solid first sedimentation tank having a hollow inside and an open top and remaining solids contained in rainwater that has passed through the first sedimentation tank. 2 sedimentation tank, The first sedimentation tank is formed so as to cross the interior space partition partition partitioning into the front space portion and the rear space portion, the inlet portion formed by the inclined plate so that rainwater flows into the rear space portion, the inlet is connected to the rear space The rainwater flowing through the inlet portion is installed in the upper portion of the first settling tank located therein is introduced into the rear space portion and the screen net formed to be inclined downward so as to be stored in the front space to roll down the rockfall of the rain, and the rear space Non-point source treatment method characterized in that it is provided on the upper part of the first settling tank located additionally having a first outflow pipe outflow rainwater to the second settling tank. 8. The method of claim 7, wherein the second carrier is dried by kneading a mixture of sulfur, pearlite, slaked lime and water, and then immersed in a calcium hydroxide solution, washed, and dried.

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