JPH11309483A - Water purifying method using wetland in combination - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the treatment of excess sludge having needed much labor in the maintenance and control in catalytic oxidation in a water purifying system combining a catalytic oxidation process and a wetland process. SOLUTION: A filamentous microorganism carrier is provided in an oxidation tank 2 in a catalytic oxidation process to conduct biological oxidation, a submerged agitating pump is arranged in the tank 2 to keep the generated excess sludge suspended without depositing it on the tank bottom, and the excess sludge is continuously charged into a wetland 3 along with the treated water. Further, a marsh basement is formed in the wetland 3 by the porous artificial media 5 having a high porosity, the excess sludge and treated water are let flow down by infiltration, and oxidative decomposition and denitrification are promoted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a wet land in which aquatic plants such as reeds are planted, and more particularly to reduction of the wet land in combination with a contact oxidation treatment process. The present invention relates to a water purification method capable of realizing efficient treatment of surplus sludge inevitably generated in a process.

[0002]

2. Description of the Related Art In recent years, attempts have been made to purify polluted water in water bodies such as river water and lake water from the viewpoint of improving the environment of rivers and lakes and maintaining ecosystems.

[0003] At present, as a purification system for rivers, a so-called "contact oxidation method between gravel" is widely used. In this method, a packed layer of gravel is artificially created in the tank, and the purification ability by the adhered microorganism film is enhanced by multiplying the adhered microorganisms. In terms of the system, water is directly pumped up from a river, flows into a reaction tank in which the above-mentioned gravel packed layer is formed, purifies polluted water, and returns to the river again.

Further, as a method without using an artificial treatment facility, in order to improve the purifying action of the river itself, the riverbed form is modified so as to increase the area of contact with water, and the purification ability by sedimentation and adhering microorganisms is improved. There is something that aims to improve. Specifically, the river width is expanded and the water depth is reduced to increase the chances of contact between the flowing water and the riverbed, and microbial carriers such as ceramics, bricks, artificial aquatic plants, and artificial turf with a large surface area are attached to the riverbed. It is intended to improve the purification ability of rivers by suspending from the surface of water and expanding the habitat area of attached microorganisms.

On the other hand, a catalytic oxidation method using a high-efficiency microbial carrier made of natural or synthetic fibers, mainly for the purpose of purifying municipal effluents and business effluents, from the viewpoint of improving the sewage purification ability. Has been put to practical use. The microbial carrier is a combination of, for example, a trunk and a loop thread, or a spirally twisted or wound one, so that microorganisms such as bacteria, fungi, protozoa, and micrometastasis can easily attach and inhabit. When suspended in a treatment tank, wastewater is introduced into the treatment tank and subjected to aeration treatment, the oxygen accompanying the aeration is sufficiently supplied to the microbial carrier, and the microorganisms are actively activated. To demonstrate. Representatively, Japanese Patent Publication No. 6-65291 and Japanese Patent Publication No. 5-48116
And the microorganism carrier described in JP-B-2-5155.

On the other hand, as a purification method that has attracted attention in recent years, there is a method of purifying sewage by using an artificial wetland in which aquatic plants such as reeds, cattails, rushes, mushrooms, and sedges are planted.
This method is superior to other purification methods in that it does not destroy the surrounding environment and maintains the ecosystem. In this case, the sewage flow-down method is classified into a surface flow method in which the surface of the wetland flows, and a seepage flow method in which the water flows in the soil. In the former surface flow method, purification is carried out in the process of contacting sewage with soil and aquatic plants (ground stems). In the latter, the permeate flow method uses rhizomes in the rhizosphere of microorganisms and aquatic plants attached to soil particles. Purification is performed by the action of decomposing and purifying by microorganisms attached to the surface and by ingesting nutrients such as phosphorus and nitrogen into plants.

[0007]

However, in the case of the contact oxidation method between gravel, clogging is liable to occur if the pollution load is too high, and excess sludge accumulated between the gravel is periodically extracted. Otherwise, there is a problem that a stable purification action cannot be maintained. At present, a backwashing diffuser is provided below the gravel layer to perform regular backwashing, and the sludge mixed liquid is directly or statically settled and then removed using a pump or the like.
Once the gravel in the tank is removed and washed, it is laid again.

Further, the purification treatment method using a microbial carrier made of natural or synthetic fibers is superior to other catalytic oxidation methods in that the equipment space is small and the treatment efficiency can be improved. The more active the group, the larger the biofilm will be and the more excess sludge will be generated. Therefore, there is a problem that a separate treatment facility is required for treating the excess sludge. Specifically, a method has been adopted in which the separated sludge is taken out, sent to a sludge concentration tank, further made into concentrated sludge, and then carried out. In any case, these catalytic oxidation methods require a great deal of equipment and labor for maintenance in order to prevent clogging and treat excess sludge.

[0009] On the other hand, the treatment method using an artificial wetland in which aquatic plants are clustered is the most promising sewage treatment method in the future in that it can purify water while improving hydrophilicity, securing a natural landscape, and maintaining an ecosystem. It is. However, compared to purification processes such as the contact oxidation method between gravel or the catalytic oxidation method using a string or a thread-like microbial carrier, the purification capacity per unit area is small, so a vast wetland area is required and the land area is narrow. There are limits to its application in Japan. In particular, it is considered difficult to adopt it for small and medium-sized rivers in urban areas where pollution is advanced. Phosphorus and nitrogen are simultaneously removed by the ingestion of nutrients by aquatic plants. However, in wetlands where the load is large, there is a problem that the nutrient removal rate is extremely reduced.

The main object of the present invention is to combine a catalytic oxidation process with a wet land process in order to pursue a next-generation purification method that is friendly to the environment and ecosystems. The required area is much smaller than that of the conventional method, and it can be easily applied in Japan. Secondly, the treatment of excess sludge, which requires a great deal of labor for maintenance in the conventional catalytic oxidation method, is facilitated. Thirdly, it is necessary to effectively remove not only BOD but also nutrients such as nitrogen and phosphorus.

[0011]

In order to solve the above problems, the present invention provides a method for cleaning polluted river water or lake water.
What is claimed is: 1. A method for purifying water, comprising purifying by a contact oxidation treatment process in a first stage and a purification process by a wet land in a second stage, wherein the microbial carrier is disposed inside the oxidation treatment tank and the biological oxidation treatment is performed. And the excess sludge generated in the oxidation treatment tank is fed into a subsequent wet land together with the treated water.

In this case, a stirring means is provided inside the oxidation treatment tank to maintain the generated excess sludge in a floating state without accumulating on the bottom of the tank, and to continuously supply the excess sludge to the wet land together with the treated water. It is desirable to do so. Preferably, the stirring means is a submersible stirring pump, one end of an air supply pipe is connected to a discharge port of the submersible stirring pump, and oxygen is supplied together with jet water from a discharge port of the submersible stirring pump. Good. Sufficient oxygen supply promotes nitrification in the catalytic oxidation treatment process, so that denitrification can be efficiently performed in the subsequent wet land. Further, in order to promote denitrification in the wet land purification treatment process, the supply amount of the excess sludge is preferably at least six times or more than the nitrate nitrogen. Biological reduction by denitrifying bacteria (2NO ₃ ⁻ + 10H ⁺ → N ₂
(↑ + 4H ₂ O + 2OH ⁻ ), when the excess sludge (organic SS) as a hydrogen donor is sufficiently supplied,
Denitrification will be performed effectively.

On the other hand, as a microorganism carrier disposed in the contact oxidation tank, a tree-shaped carrier having a loop yarn projecting outward from a trunk portion, or a large number of horizontal fiber yarns can be formed in a vertical direction. A wide variety of materials, such as a surface formed by binding with a thread or a fixing member and a net-shaped material, can be used. In the present specification, these are generally referred to as "filamentous microbial carriers" in the sense that a filamentous member is used as a main microorganism carrier.

In terms of supporting microorganisms, microbial carriers such as gravel, ceramics, bricks, and plastics perform the same function. However, the present invention aims at making maintenance sludge free of excess sludge, and the microbial membrane becomes somewhat enlarged. If you do, the tree-like,
It is preferable to use the above-mentioned filamentous microorganism carrier in which the microorganism support is a linear member, such as a surface formed by a fiber thread or a net-like microorganism carrier.

Further, in the wet land, it is preferable to use an artificial filler having a porosity of at least 90% as a wetland base material, and to use a flow-down system of polluted water as a permeation flow. By using porous and high porosity artificial media as a wetland base material, the amount of microorganisms increases and oxidative decomposition can be performed efficiently,
Purification efficiency is improved by using a permeate flow. Either way, it will greatly contribute to making the wetland compact. Further, in order to effectively suppress clogging between wetland base materials, coarse particles such as sand mixed in river water or lake water are removed by a separation treatment process in the preceding stage of the contact oxidation treatment process. It is desirable to do so.

On the other hand, when a desired phosphorus removal rate cannot be achieved only by ingestion of aquatic plants with respect to the removal of the phosphorus compound, a metal-based porous material such as iron or aluminum is removed following the wetland purification treatment process. A filled dephosphorization facility is provided, and dephosphorization is performed on the treated water that has passed through the wet land.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic diagram of a water purification system according to the present invention, FIG. 2 is a plan view (partially bottom surface) of a wet land 3, and FIGS.

The present water purification system comprises a sand basin 1 and a contact oxidation treatment tank 2 as a pretreatment facility, and a reduced wet land 3 (hereinafter referred to as a compact wet land) as a post treatment facility. The most characteristic point is that the excess sludge generated by the contact oxidation treatment together with the treated water is discharged together with the treated water from the contact oxidation treatment tank 2 to the compact wet land 3. In the treatment tank 2, the point that a filamentous microbial carrier is used to increase the efficiency of BOD removal and promote nitrification, the introduction of the excess sludge into the compact wet land 3, and the promotion of nitrification in the pretreatment facility In combination, the efficient denitrification in the compact wet land 3 is realized, and the compact wet land 3 is effectively removed to effectively remove phosphorus compounds. Portland 3 to point to features a waterway filled with metallic porous body such as iron or aluminum adjacent the like as a main characteristic points.

The sedimentation basin 1 is used to prevent clogging between particles such as gravel or artificial media constituting a wetland base in the compact wetland 3 which is a post-process, and the cause of the clogging from polluted water taken in from a river. It is installed in order to remove coarse particles such as sand in advance, and the sand removed in the sand basin 1 is returned to the river again. The sedimentation basin 1 is arranged in two lines side by side and used alternately, and the deposited sand is carried out by a clamshell, a backhoe or the like in a timely manner. The point is that it is only necessary to remove sand causing blockage in the compact wet land 3. Therefore, in addition to the means by natural settling such as the sand basin 1, a liquid cyclone, a rotary classifier,
A method using mechanical separation such as a classifier or a vibrating screen may be used.

Next, in the present embodiment, for example, as shown in FIGS.
A and a plurality of treatment tanks, such as the second treatment tank 2B, are arranged side by side. The polluted water from the sand basin 1 is introduced into the tank via the measuring tank 23. Inside the first treatment tank 2A and the second treatment tank 2B, the filamentous microorganism carrier 2 is provided.
0 and 20 are provided, respectively, and submerged stirring pumps 21 and 21 are installed at the bottom of the tank. The underwater stirring pump 21 has a diffuser pipe 21a at a discharge port, an end of an air supply pipe 24 is connected to a base end of the diffuser pipe 21a, and air supplied through the air supply pipe 24 is used for the underwater stirring pump. The water is supplied into the tank together with the jet water discharged from the tank 21.

The polluted water that has flowed into the tank is biodegraded by microorganisms such as bacteria, fungi, protozoa, and micrometamorphous animals carried on the filamentous microbial carrier 20, thereby removing BOD. . In addition, nitrification, in which ammonia is oxidized by nitrifying bacteria in an aerobic atmosphere accompanying aeration and turned into nitrate nitrogen, is effectively promoted.

The microorganisms adhering to the filamentous microorganism carrier 20 are separated by their own weight due to enlargement and become surplus sludge as they are. In the present invention, the separated sludge is separated from the bottom of the tank by the jet water flow from the underwater stirring pump 21. It is circulated in a floating state without sedimentation, and is continuously guided to the subsequent compact wet land 3 together with the treated water. Therefore, no surplus sludge is accumulated at the bottom of the contact oxidation treatment tank 2, and the sludge treatment equipment that has been conventionally required can be eliminated. Note that the underwater stirring pump 21 may use a stirring means such as an underwater stirrer instead of the pump for the purpose of not depositing excess sludge on the bottom.

On the other hand, the filamentous microorganism carrier 20 includes:
Any form can be used in accordance with the present invention.

The first filamentous microbial carrier 20A shown in FIGS. 6 to 8 has a cross section from the side surface of the hollow stem 30 woven in a cylindrical shape, and is provided with bacteria, fungi, protists, micrometastasis and the like. A large number of fiber yarns 31A to 31D formed by bundling fiber yarns of a specific material to which the microorganisms easily attach and easily inhabit are formed in a loop shape and along the hollow trunk 30, and the core material 14 is inserted into the hollow trunk 30. It has some degree of independence. As shown in FIG. 6, for example, as shown in FIG. 6, the upper and lower ends of the filamentous microorganism carrier 20A are supported by an upper support 28 and a lower support 29, respectively. Place within. Then, when the sewage is introduced into the treatment tank and subjected to aeration treatment, the oxygen accompanying the aeration is sufficiently supplied from the outside and inside (the inside of the loop) to the microorganism carrier, and the aerobic microorganisms are activated actively. , Exhibit a high purification ability.

Next, the filamentous microorganism carrier 2 shown in FIG.
OB indicates a number of fiber yarns 2 arranged along the lateral direction.
7, 27 ... are fixed by fixing members 26, 26 ... composed of a bundle of a plurality of warp yarns arranged in the longitudinal direction.
The distance between the fixing members 26, 26,... Is slightly reduced by horizontally arranged distance regulating yarns 25, 25, so that the fiber yarns 27, 27,. .

Further, the filamentous microbial carrier 20C shown in FIG. 10 is composed of a bundle of a plurality of warp yarns arranged in a vertical direction by fixing a large number of fiber yarns 27 arranged in a horizontal direction. Are fixed by the members 26, 26, and when the fixing members 26, 26,... Are attached to the support, they are separately supported by the upper support 28 and the lower support 29, and the fixing members 26, 26,. The fiber yarns 27, 2
7 are bulged laterally in a wavy manner.

[0027] As in the case of the filamentous microorganism carriers 20A to 20C, if a filamentous member (including a string-like member) is used as a main microorganism support, the microorganisms will spontaneously peel off when the microorganisms grow to a certain degree of their own weight. Since it proceeds, it can be suitably used in accordance with the gist of the present invention. That is, maintenance is unnecessary because the microorganisms are naturally stripped off. Note that the same applies to a case where a string-like or fibrous yarn is arranged in the vertical and horizontal directions and the crossing portions are connected to form a lattice-shaped microorganism carrier.

On the other hand, the compact wet land 3 is preferably filled with a wetland base material made of gravel or artificial media, and a reed is preferably vegetated on the wetland base material. As described above, there are a surface flow method and a permeation flow method as the flow-down method of sewage. The permeation flow method is recommended from the viewpoint of purification efficiency. Trial calculations confirm that the wetland area can be reduced to 1/5 or less as compared with the surface flow method. The only drawback with the permeate flow method is that clogging is likely to occur. Although relative, it has been found that clogging is less likely to occur by inhabiting a reed as an aquatic plant than by other aquatic plants, and that clogging is less likely to occur by sufficiently developing a rhizosphere. In addition, clogging can be effectively suppressed by selecting a porous and high porosity artificial medium for the wetland base material. Specifically, for example, artificial media having a porosity of 90% or more using natural materials such as coconut fiber and coconut fiber and artificial fiber materials such as polypropylene, Saran fiber, vinylidene chloride, rock wool, and urethane are used to reduce the porosity. Artificial media with 90% or more is suitably used. In addition, the water flow direction is desirably a vertical flow because the flow distance can be shorter than that in the horizontal direction in order to prevent clogging. Specifically, as shown in FIG. 2, a water pipe 8 is laid on the upper surface of the compact wet land 3 and a water collecting pipe 9 is laid on the bottom surface of the wetland base material so that the water flow direction is vertical. I do.

The reed reaches 60 cm or more in the rhizosphere,
Since the root zone is deeper in the rhizosphere than other water extraction plants,
Oxygen supply capacity is higher than other water extraction plants, and can be suitably selected as a wetland aquatic plant of the infiltration flow system.

While the BOD is removed by the pretreatment, the excess sludge (organic SS) together with the nitrified treated water is simultaneously supplied to the compact wet land 3, which flows while penetrating the wetland base material. It is oxidatively decomposed by aerobic microorganisms attached to the surface of the rhizosphere, and some nutrients such as phosphorus and nitrogen are absorbed and removed from the root. In the anaerobic zone outside the rhizosphere, nitrated nitrate nitrogen is reduced to nitrogen gas by the denitrifying bacterium, which is an anaerobic microorganism, and released to the ground through the rhizome. The surplus sludge (organic SS) is effectively used as a hydrogen donor during the biological reduction action by the denitrifying bacteria, thereby promoting denitrification. In other words, according to the present invention, the denitrification can be effectively performed by putting excess sludge (organic SS) generated in the contact oxidation tank into the wet land.

At this time, in order to promote denitrification more effectively, it is important that excess sludge (organic SS) as a hydrogen donor be sufficiently supplied to the anaerobic zone. When BOD in wastewater is used as a hydrogen donor to remove nitrate nitrogen by reducing it to nitrogen gas, the amount of nitrogen must be three times or more (weight ratio) of nitrogen.
Is not necessarily converted to 100%, and the conversion rate is 50% at the maximum. Therefore, at least the organic SS is added at least 6 times with respect to nitrogen.

Further, since the removal rate of phosphorus in the compact wet land 3 can be expected only by absorption and removal by reeds, if a higher phosphorus removal capacity is required, the phosphorus is removed below the wetland base material 5. The treated water from the perforated water collecting pipe 6 is introduced into a dephosphorization channel once filled with a metal-based porous body 7 such as iron or aluminum, and is adsorbed on the metal-based porous body 7. To do. The phosphate ions are basically reacted with iron ions and aluminum ions and removed as insolubles. Iron plates, iron cans, aluminum cans and the like can be used as a material for supplying iron ions and aluminum ions, but a metal-based porous body 7 having a three-dimensional knitted structure can be used.
Has a large specific surface area and is excellent in contact efficiency, so that it can be used more preferably than others. Note that the treated water that has passed through the dephosphorization channel is discharged again to a river.

[0033]

As described above in detail, according to the present invention, by combining the contact oxidation process and the wet land process, the required area can be remarkably reduced as compared with the conventional wet land, and it can be easily realized in Japan. Applicable. In addition, since the excess sludge generated in the preceding contact oxidation process is directly introduced into the wet land, the excess sludge treatment equipment that was conventionally separately required in the contact oxidation treatment becomes unnecessary, and the maintenance and management can be facilitated. Become like Further, not only BOD but also nutrients such as nitrogen and phosphorus can be effectively removed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a water purification system according to the present invention.

FIG. 2 is a plan view (partially a bottom surface) of the compact wet land 3;

FIG. 3 is a side view of the contact oxidation treatment tank 2;

FIG. 4 is a plan view of a contact oxidation treatment tank 2;

FIG. 5 is a vertical sectional view of the contact oxidation treatment tank 2 (viewed along the arrow IV-IV in FIG. 2).

FIG. 6 is a structural perspective view of a filamentous microorganism carrier 20A.

FIG. 7 is an enlarged perspective view of a filamentous microorganism carrier 20A.

FIG. 8 is a cross-sectional view of the filamentous microorganism carrier 20A.

FIG. 9 is a structural perspective view of another filamentous microorganism carrier 20B.

FIG. 10 is a structural perspective view of another filamentous microorganism carrier 20C.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sand basin, 2 ... Contact oxidation treatment tank, 3 ... Compact wet land, 4 ... Reed, 5 ... Wetland base, 6 ... Water collecting pipe,
7 ... metal-based porous body, 8 ... water sprinkling pipe, 9 ... water collecting pipe, 20
20A / 20B / 20C: Filamentous microorganism carrier, 21: Submersible stirring pump, 24: Air supply pipe

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[Procedure amendment]

[Submission date] February 5, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a water purification method for purifying polluted water by a first-stage contact oxidation treatment process and a second-stage wet land purification treatment process. In the above-mentioned contact oxidation treatment process, a microorganism carrier is disposed inside the oxidation treatment tank, purification is performed by biological oxidation treatment, and excess sludge generated in the oxidation treatment tank is put into a subsequent wet land together with treated water. It is characterized by doing so.

 ──────────────────────────────────────────────────続 き Continued on the front page (71) Applicant 000140292 Okumura Gumi Co., Ltd. 2-2-2 Matsuzakicho, Abeno-ku, Osaka-shi, Osaka (71) Applicant 000001373 Kashima Construction Co., Ltd. 1-2-2 Moto-Akasaka, Minato-ku, Tokyo No. 7 (71) Applicant 000140694 Kato Construction Co., Ltd. 19-1, Kanie-Nitta-shi, Shiga-machi, Kanie-cho, Kaifu-gun, Aichi (71) Applicant 000104191 Kanatsu Giken Kogyo Co., Ltd. 636 Kasuga-cho, Matsue-shi, Shimane 71) Applicant 000162593 Kyowa Exio Co., Ltd. 3-29-20 Shibuya, Shibuya-ku, Tokyo (71) Applicant 000001317 Kumagaya Gumi Co., Ltd. 2- 6-8 Chuo, Fukui City, Fukui Prefecture (71) Applicant 391019740 Sanshin Construction Industry 1-2-7 Koraku, Bunkyo-ku, Tokyo (71) Applicant 000006655 Nippon Steel Corporation 2-6-Otemachi, Chiyoda-ku, Tokyo No. 3 (71) Applicant 390036504 Nittoku Construction Co., Ltd. 8-14-14 Ginza, Chuo-ku, Tokyo (71) Applicant 000004422 Nippon Kentei Co., Ltd. 1-1-1, Yamate, Funabashi-shi, Chiba (72) Invention Person Keigo Nakamura 1 Asahi, Oaza, Tsukuba City, Ibaraki Prefecture Inside the Public Works Research Institute, Ministry of Construction (72) Inventor Shopachi Tajima 2-2 Nishizawa, Tsukuba City, Ibaraki Prefecture Inside the Technical Research Institute, Public Works Research Center (72) Inventor Kazuo Murahashi Osaka City, Osaka Prefecture No. 7-6, Bashizashi-cho, Tennoji-ku Co., Ltd. Osaka Waterproof Construction Co., Ltd. (72) Inventor Kazunari Mukai 7-6, Nashisashicho, Tennoji-ku, Osaka, Osaka Co., Ltd. Okumura Gumi, Inc. 2-2-2 Matsuzaki-cho, Abeno-ku, Osaka City, Osaka (72) Inventor Yuaki Shiraishi 2-2-2 Matsuzaki-cho, Abeno-ku, Osaka City, Osaka Prefecture Okumura Gumi, Inc. (72) Inventor Haruki Wakimoto Kashima Construction Co., Ltd. 1-2-7 Moto-Akasaka, Minato-ku, Tokyo (72) Inventor Ta Naka Toshiki Kashima Construction Co., Ltd., 1-2-7 Moto-Akasaka, Minato-ku, Tokyo (72) Inventor Yoshiyuki Hamada Kanie-cho, Kaifu-gun, Aichi Prefecture 72) Inventor Sato Inada, 636 Kasuga-cho, Matsue-shi, Shimane Prefecture Inside Kanatsu Giken Kogyo Co., Ltd. Noboru 2-1, Tsukudo-cho, Shinjuku-ku, Tokyo Kumagaya Gumi Tokyo headquarters (72) Inventor Kazumi Osawa 1-2-7 Koraku, Bunkyo-ku, Tokyo Sanshinken Construction Industry Co., Ltd. (72) Inventor Shinsaka Takashi 1-2-7 Koraku, Bunkyo-ku, Tokyo Sanshin Ken Construction Industry Co., Ltd. (72) Inventor Osamu Miki 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Corporation (72) Inventor Kazuhisa Fukunaga Chiba 20-1 Shintomi, Futtsu City Nippon Steel Corporation (72) Inventor Kazuyuki Tamaki 8-14-14 Ginza, Chuo-ku, Tokyo (72) Inventor: Hikaru Ishida 1-1-1 Yamate, Funabashi-shi, Chiba Nipponken Steel Corporation

Claims (8)

[Claims] Claims: 1. The polluted river water or lake water, etc.
A water purification method for purifying water by a first-stage contact oxidation treatment process and a second-stage wet land purification treatment process, wherein in the contact oxidation treatment process, a microorganism carrier is disposed inside an oxidation treatment tank, and biological oxidation treatment is performed. A method for purifying water using wet land in combination, wherein excess sludge generated in the oxidation treatment tank is supplied to a subsequent wet land together with treated water. 2. An agitation means is provided in the inside of the oxidation treatment tank so that the generated excess sludge is maintained in a floating state without accumulating on the bottom of the tank, and the excess sludge is continuously supplied to the wet land together with the treated water. A method for purifying water using a wet land according to claim 1. 3. The underwater stirring pump is connected to one end of an air supply pipe at a discharge port of the underwater stirring pump.
3. The water purification method according to claim 1, wherein oxygen is supplied together with jet water from a discharge port of the underwater stirring pump. 4. The water purification method according to claim 1, wherein a filamentous microorganism carrier is used as the microorganism carrier. 5. The wet land purification process according to claim 1, wherein an artificial filler having a porosity of at least 90% is used as a wetland base material, and the flow of polluted water is a permeation flow. Water purification method by using in combination with wetland. 6. The water quality in combination with wet land according to any one of claims 1 to 5, wherein the supply amount of surplus sludge is at least 6 times or more of nitrate nitrogen in order to promote denitrification in said wet land purification treatment process. Purification method. 7. A dephosphorization facility filled with a metal-based porous material is provided subsequent to the wet land purification process, and dephosphorization is performed on treated water permeated through the wet land. A method for purifying water using a wet land according to any one of 1 to 6. 8. The water purification according to claim 1, further comprising a process of separating coarse particles mixed in river water or lake water before the contact oxidation process. Method.