JP2003311294A - Tubular body for purification of sewage and method for purifying sewage by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tubular body for purification of sewage for removing pollutants contained in a water mass and for recovering useful resources by making eutrophic and poor-oxygen or anoxic polluted water mass pass through the tubular body where photosynthetic bacteria are deposited and grown so as to promote photosynthesis, and to provide a method for purifying sewage to purify an eutrophic water region at a low cost with low energy. <P>SOLUTION: The tubular body for purification of polluted water comprises such tubular bodies that at least a part of the inner wall has a function of depositing photosynthetic bacteria and photosynthesis can be promoted by making poor-oxygen or anoxic polluted water pass through the tubular bodies. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a sewage purification tubular body for purifying contaminated water quality such as found in eutrophic water areas and livestock wastewater, and recovering useful resources, and the same. Regarding sewage purification method.

[0002]

2. Description of the Related Art In recent years, deterioration of water quality due to eutrophication has become a serious problem in dam areas such as dam lakes, reservoirs, inner bays, and fishing ports. In addition, there are many reports of water-blooms and freshwater red tides in the water area that serves as the source of tap water, and the interest in water quality at the civic level has risen to a level unprecedented. As the cause of eutrophication, the decomposition of the leaves that flow into the water in the mountains,
Excessive influx of nitrogen and phosphorus into the water area due to inflow of domestic wastewater in urban areas such as excretion of human waste from dairy farming and livestock is considered. The inflow to these waters promotes the overgrowth of phytoplankton and their dead bodies (Detritus).
Settles and significantly increases the organic content of the sediment.
As a result, when a density stratification is formed due to a rise in water temperature of the surface layer, invasion of salt water, etc., the bottom layer portion is easily deoxidized and deoxidized. In surface water containing oxygen, the concentration of dissolved substances is generally low due to biochemical reactions. On the other hand, dissolved substances are accumulated in the bottom water at a high concentration, and improving the quality of the bottom water is a very important issue.

Conventionally, a deep layer aeration method and an activated sludge method have been generally used as a sewage treatment method. The deep aeration method includes a method for directly dissolving oxygen in the bottom water by aeration,
There is a method of destroying stratification by aeration to promote vertical mixing. However, in the former deep aeration method, the oxygen supply rate to the bottom layer water is limited to the solubility of oxygen from the air sent to the bottom layer to water, and in reality it is not possible to realize sufficient oxygen supply. is there. In the latter deep aeration method, there is a problem that it is almost impossible to mix the whole water area because the horizontal range affected by aeration is limited. In addition, both deep aeration methods employ a method in which air having a density that is overwhelmingly smaller than that of water is sent to the bottom layer, so enormous artificial energy must be input and enormous cost is required. In addition, there is a problem of environmental load due to a large amount of energy input. In wastewater treatment such as the activated sludge method, a large amount of by-products such as sludge is generated in the treatment process, and treatment such as dehydration / drying is required, resulting in the problem that high cost and high energy must be input.

On the other hand, when a density stratification is formed in a eutrophic water area, photosynthetic bacteria may rarely accumulate near the pycnocline. This is because photosynthetic bacteria are vulnerable to competition with phytoplankton, which performs oxygen-generating photosynthesis, and that the number of individuals cannot increase near the surface of the water where light can reach sufficiently. This is because it is possible to use the nutrient salt of. As a method for purifying sewage using the above-mentioned photosynthetic bacteria, there is a method in which the photosynthetic bacteria are fixed to a ceramic carrier or a gel-like substance to maintain the population. For example, Japanese Patent Application Laid-Open No. 9-85282 discloses that "agar gel fixes photosynthetic bacteria, a river,
A water quality improving device for lakes and marshes is disclosed. JP-A-9
Japanese Patent No. 234482 discloses "a floating water purification apparatus and a water purification method in which water in a stratified lake or the like is vertically stirred." Japanese Unexamined Patent Publication No. 9-75985 discloses "a water purification device in which photosynthetic bacteria are attached to a porous carrier". Japanese Patent Application Laid-Open No. 11-289913 discloses "a purification filter and a purification device for aquaculture breeding water in which a photosynthetic organism is attached to a fiber".

However, the conventional methods for purifying sewage using photosynthetic bacteria have the following problems. JP-A-9
Since the water quality improving device in Japanese Patent No. 85282 fixes photosynthetic bacteria to agar gel, it takes 1 to 2 weeks.
There is a problem that the gel collapses after continuous operation for about a week, and the purification ability decreases. The floating-type water purification device in Japanese Patent Laid-Open No. 9-234482 uses photosynthetic bacteria partially, but does not collect nitrogen and phosphorus, so the total amount of nitrogen and phosphorus contained in the water area does not decrease. Therefore, although the water quality is temporarily improved during the operation of the device, there is a problem that the water quality is restored after the operation is stopped for a while.
In addition, a large amount of energy is required for purification, and there is a problem that valuable materials cannot be recovered. In the water purification apparatus disclosed in Japanese Patent Laid-Open No. 9-75985, oxygen is consumed as it progresses from the surface of a carrier using activated carbon or the like to the inside, and photosynthetic bacteria become active in the place where oxygen disappears. It is greatly attenuated (light disappears before oxygen), and there is a problem that sufficient photosynthetic activity cannot be obtained. In addition, the photosynthetic bacteria that have proliferated are incorporated into the food chain of the body of water, and thus play a role of water purification, but there is a problem that valuable materials cannot be recovered. The purification filter and the purification device in JP-A No. 11-289913 selectively irradiate a wavelength advantageous for photosynthesis, but since the treatment target is water for breeding cultured fish, it contains a considerable amount of oxygen. There is a problem that photosynthetic bacteria are unlikely to occur under such conditions. Since water containing oxygen is the target of treatment, it is difficult to maintain the type of photosynthetic bacteria that exerts its purifying ability under anaerobic conditions.

In addition, in the conventional method for purifying sewage using photosynthetic bacteria, heterogeneity of various elements related to metabolic activity of photosynthetic bacteria such as light conditions, nutritional conditions, anaerobic and aerobic conditions occurs, and all photosynthetic bacteria are caused. There is a problem that the effective activity of the can not be expected. In addition, it is necessary to artificially irradiate the inside of a reactor or the like with controlled oxygen conditions to adjust the conditions of oxygen and light, and to install the reactor, transport water from the wastewater generation source to the reactor, and use energy for the light source. However, there is a problem in that a large amount of labor and energy must be input. On the other hand, it has been pointed out that phosphorus as a resource may be depleted in the near future, and effective resource measures such as recovery of phosphorus are strongly desired.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to remove a polluted water mass that has been eutrophic, deoxidized, or deoxidized.
Passing through a tubular body to which photosynthetic bacteria are adhered and grown, and promoting photosynthesis, while removing pollutants contained in the water mass, providing a sewage purification tubular body that recovers useful resources, and An object of the present invention is to provide a sewage purification method for purifying a eutrophic water area at low cost and with low energy.

[0008]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have shown that photosynthetic microorganisms cannot predominate in the presence of phytoplankton found in eutrophic waters. The present invention has been completed by discovering that, when light conditions are satisfied under a condition where phytoplankton is absent or abundant (for example, filtered water), active activities are performed and a large amount of nutrient salts are absorbed.

That is, the present invention provides the following [1] to [1]
[0]]. [1] A tubular body for purifying wastewater, wherein at least a part of the inner wall surface has a photosynthetic microorganism-adhering ability, and is composed of a tubular body capable of photosynthesizing by passage of deoxygenated or deoxygenated wastewater. [2] The sewage purification tubular body according to [1], wherein at least a part of the inner surface of the tubular body is a polymer having a photosynthetic microorganism adhering ability and a light transmitting ability. [3] The sewage purification tubular body according to [2], wherein the polymer has gas permeability. [4] The sewage purification tubular body according to [2] or [3], wherein the polymer is at least one selected from polytetrafluoroethylene, polyvinyl chloride, and silicone resin. [5] The tubular body for purifying wastewater according to any one of [1] to [4], wherein the tubular body has a circular shape, a polygonal shape, or a combination thereof. [6] A method for purifying sewage, characterized in that the tubular body according to any one of [1] to [5] is passed through the sewage deoxidized or deoxygenated in the tubular body in the presence of a trace amount of oxygen. . [7] The method for purifying sewage according to [6], wherein after adhering the photosynthetic microorganisms to the tubular body, sewage is passed through the tubular body. [8] The method for purifying sewage according to [6] or [7], which comprises recovering valuable substances attached to the tubular body after purifying sewage. [9] The valuable material is a phosphorus-containing material [8]
The sewage purification method described in. [10] The wastewater purification method according to any one of [6] to [9], wherein the wastewater is anaerobic wastewater.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The present invention attaches photosynthetic microorganisms predominantly in the vicinity of the stratum corneum in the on-site water area to the inner wall surface of a sewage purification tubular body installed on a water surface with good light conditions, and photosynthesis occurs in the absence of competing phytoplankton. Is performed to remove high-concentration pollutants dissolved in water and to recover valuable substances such as phosphorus-containing substances.

The material of the tubular body in the present invention is not particularly limited as long as at least a part of the inner wall surface has photosynthetic microorganism adhering ability, but a material having unevenness on the inner wall surface of the tubular body is used. Then, the photosynthetic microorganisms are easily attached to the inner wall surface, and the attachment area is increased, which is preferable. A polymer in which at least a part of the inner surface of the tubular body has photosynthetic microorganism adhesion and light transmission properties, for example, polytetrafluoroethylene, polyvinyl chloride, silicone resin, polyethylene, polystyrene, AS resin, ABS resin, polypropylene, acrylic resin, Methacrylic resin, polyethylene terephthalate, polyamide, polycarbonate, polyacetal, modified polyphenylene ether, polybutylene terephthalate, polyphenylene sulfide, polyarylate, polysulfone, polyethersulfone, polyetheretherketone, polyetherimide, polyamideimide, liquid crystal polymer, polyimide, Polyphthalamide, polyacrylonitrile, fluororesin, phenolic resin, urea resin, melamine resin, epoxy resin, unsaturated polyester Le, polyurethane, diallyl phthalate resin, or alkyd resins, polylactic acid, polyhydroxybutyric acid,
It is preferable to use one or more biodegradable polymers such as polycaprolactone, polybutylene succinate, polyethylene succinate, polyvinyl alcohol and polyurethane in order to avoid the problem of plastic waste treatment on a global scale. Among them, a polymer having gas permeability is preferable. However, when oxygen required for growth of photosynthetic microorganisms is supplied from the sewage, it does not need to have gas permeability. The photosynthetic bacteria-adhering ability, light-transmitting ability, and gas-permeating ability do not need to be provided on the entire inner surface of the tubular body, and may be part thereof.

Here, the photosynthetic microorganism adhering ability means the property that one or more photosynthetic microorganisms adhere to the inner wall surface of the tubular body, and if the inner wall surface has irregularities, the adhering ability increases. The gas permeation performance refers to the property of supplying an appropriate amount of oxygen from the outside of the tubular body through a process such as molecular diffusion, which is required when the photosynthetic microorganisms attached to the inner wall surface of the tubular body perform photosynthesis. The light transmission performance refers to the property of transmitting a required amount of light when the photosynthetic microorganisms attached to the inner wall surface of the tubular body perform photosynthesis. A material having a light transmittance that maximizes the metabolic activity of photosynthetic bacteria is preferable. For example, in the case of purple sulfur bacteria, a material that transmits light of about 5000 lux or less, which maximizes metabolic activity, is preferable. Light stronger than this may cause damage such as inactivation of photosynthetic bacteria. In this case, some kind of light shield must be provided.

Examples of the photosynthetic microorganisms used in the present invention include anaerobic photosynthetic bacteria and anaerobic photosynthetic microorganisms. Specifically, it is a bacterium that grows by photoinorganic nutrition or photoorganotrophy using light energy, and there are Rhodospirillum genus, Rhodopseudomonas genus, Chromatheum genus, Chloroflexus genus, Chlorobium genus, etc. Filidis, Rhodospirillum rubrum and the like are preferably used.
For example, for sewage sludge, Rhodo-Pseudo-Momas pulse tris (Joong Kyun Kim, Bum-kyu Lee, Sang-Hee Kim,
Jung-Hye Moon, Aquacultural Enginnering, 1999 ), and red sulfur bacteria (JLSund, CJ Even
son, KA Strevett, RW Nairn, D. Athay, E. Trawi
nski, Journal of Environmental Quality, 2001 ), non-sulfur photosynthetic bacteria belonging to the genus Rhodrum in the ocean
(Tadashi Matsunaga, Tomoyuki Hatano, Akiyo Yamada,
Mitsufumi Matsumoto, Biotechnology and Bioengineer
ing, 2000 ) is used. In particular, purple sulfur bacteria
Organic compounds can be photo-assimilated, such as fatty acids,
Other organic acids, primary and secondary alcohols, carbohydrates, aromatics are also assimilated. In addition, these photosynthetic bacteria can simultaneously utilize most of the organic substances capable of photoassimilation as respiratory substrates. Further, it is possible to grow photoautoautotrophically using a reduced inorganic sulfur compound. These photosynthetic bacteria may be sampled from a highly concentrated habitat such as a lake, cultivated and concentrated, or commercially available photosynthetic bacteria may be used. Further, as a carrier for entrapping immobilization of photosynthetic bacteria, there are natural polymer gels such as agar, color geninan, alginic acid and the like, and polyvinyl alcohol, synthetic polymer gels such as polyacrylamide, but also as nutrient salts for photosynthetic bacteria and other existing microorganisms. Available agar is used. Anaerobic photosynthetic bacteria grow in an environment where there is little light such as a water temperature stratified layer, but oxygen is contained in a very small amount.

The shape of the tubular body used in the present invention may be a polygon such as a circle, a square, a rectangle, a rhombus, a triangle, a pentagon, and a hexagon, or a combination thereof, but is not limited thereto. . The length of the tubular body is
It is not particularly limited and can be appropriately changed according to the installation place.

The sewage used in the present invention is deficient or anoxic sewage, and specific examples include eutrophication bottom water, livestock wastewater, and factory wastewater, but are not limited thereto. Not something. Anaerobic sewage is preferred because it promotes the metabolic activity of photosynthetic bacteria. Here, hypoxia means that a small amount of molecular oxygen is dissolved, but the dissolved oxygen concentration is such that organisms that perform aerobic metabolism such as fish are difficult to continuously grow. Means decrease. Further, deoxidation means that molecular oxygen is deficient.

The sewage purification tubular body of the present invention is composed of one or more tubular bodies, but the number or arrangement of the tubular bodies may be appropriately changed depending on the place of installation. The sewage purification tubular body of the present invention purifies contaminated water quality such as that found in eutrophied water bodies and livestock wastewater, recovers useful resources, and is used in combination with aquaculture cages in various ways. Widely used for purposes.

[0017] In aquaculture cages, pollutants are deposited directly below the cages due to excessive bait dispersion and excretion of cultured fish, and often the surrounding bottom water quality is deteriorated. When the tubular body according to the present invention is used in combination with the aquaculture cage, it is possible to improve the water quality of the water area, especially immediately below the aquaculture cage where the contamination is remarkable. As described above, when the tubular body according to the present invention is used together with the aquaculture cage, the purification can be performed more efficiently than when the tubular body according to the present invention is installed in other relatively uncontaminated water area. Further, by using it together with the aquaculture cage, it is possible to reduce the labor and cost of separately installing the system of the tubular body for purifying sewage of the present invention.

At present, the livestock wastewater discharged from a livestock house is often retained in a sedimentation basin for a certain period of time and discharged as it is. In most cases, the bottom layer of the sedimentation basin is deoxidized, so that application of the present invention makes it possible to construct a very simple facility, low cost, and low environmental load purification system.

The sewage purification method using the sewage purification tubular body of the present invention will be described below. When the tubular body of the present invention installed on a water surface with good light conditions is filled with sewage that is deoxygenated or deoxygenated in the presence of a trace amount of oxygen, a photosynthetic microorganism that predominates near the stratum corneum in the on-site water area is present. It adheres to the inner wall surface of the tubular body of the invention. Then, due to the gas permeability of the tubular body, oxygen permeates from the periphery of the tubular body into the tubular body, and the vicinity of the inner wall to which the photosynthetic microorganisms are attached becomes an ideal microaerobic condition for growth. Usually, dissolved oxygen, which is a substrate for metabolism of photosynthetic microorganisms, is accumulated in high concentration in sewage (bottom layer water) that has been deoxidized or deoxidized. Then, photosynthesis is carried out in the absence of competing phytoplankton as described above, high-concentration pollutants dissolved in water are removed, and valuable substances are recovered as necessary.

Here, the trace amount of oxygen means the amount of oxygen required for photosynthesis by the photosynthetic microorganism used in the present invention. When oxygen is present in excess, the photosynthetic activity of the photosynthetic microorganism is reduced or the photosynthetic activity is lost. On the other hand, when the photosynthetic microorganism of the present invention is immobilized using a carrier, the photosynthetic microorganism is attached to the tubular body, and then the oxygen-depleted or deoxygenated waste water is passed through the tubular body.

As a method for adhering the photosynthetic microorganisms, the photosynthetic microorganisms are adhered and proliferated on the inner wall surface of the tubular body by making the inside of the tubular body a microaerobic condition ideal for the growth of the photosynthetic microorganisms by diffusion supply of oxygen or the like. However, the method is not limited to these.

Examples of valuable substances or pollutants to be recovered according to the present invention include phosphorus, nitrogen, metals such as iron, copper, zinc, nickel, manganese, cadmium, mercury and antimony, and organic tin compounds (tributyltin compound, dibutyltin). Compounds, monobutyltin compounds, triphenyltin compounds), phthalates, phenols (nonylphenol, bisphenol A), organochlorine compounds (PC
B, dioxins, etc., environmental hormones, various antibiotics, etc., but not limited thereto.
As a method of recovering the valuable resource, any known method can be used and is not limited.

The sewage purification system using the tubular body of the present invention will be specifically described below with reference to the drawings. (Embodiment 1) FIG. 1 is a configuration diagram showing a sewage purification system in a eutrophic water area, and FIG. 2 is a schematic view of a main part of the sewage purification system.

In FIGS. 1 and 2, 1 is a sewage purification system, 2 is a sewage purification tubular body in which red sulfur bacterium, which is one of photosynthetic microorganisms, is adhered and grown on the inner wall surface, 3 is a sewage purification tubular body 2 is a floating body, 4 is a pump for pumping water below the density layer to the tubular body 2, 5 is a pumping pipe for pumping water below the density layer to the tubular body 2, 6
Is a wire for adjusting the horizontal and vertical positions of the floating body 3, 8
Is a water supply pipe for supplying treated water after purification and resource recovery to the lower layer again, 9 is a weight for adjusting the vertical position of the floating body 3, 10 is an anchor, 11 is a valve for adjusting the flow rate, 1
Reference numeral 2 is a photovoltaic power generator that drives the pumping pump 4.

In the present system 1, the wire 6 is in a state of hanging from the anchor 10 via a pulley installed on the floating body 3, and a weight 9 is provided at the tip of the wire 6. That is, the wire 6 is the floating body 3.
It is possible to adjust the horizontal and vertical position of the and is always in tension. In addition, the floating body 3 has a downward force by the weight 9, a lateral force from the anchor 10,
Due to the upward force of the buoyancy 3, it is stationary where the balance is maintained. Therefore, the advantage of the present system 1 is that it can cope with water level fluctuations such as tide. For example, when the water surface rises, it is necessary to extend the wire 6 from the anchor 10 to the floating body 3, but the wire 6 extending vertically downward from the floating body 3 is automatically adjusted accordingly. In this system 1, since the bottom layer water that has become deficient or anoxic due to eutrophication is targeted, the bottom layer water is temporarily pumped up to a floating body, where purification and resource recovery are performed, and the bottom layer water is collected. It is a return system. Further, since the series of tubular bodies 2 are attached to the floating body 3, and the floating body 3 can be installed completely independently of other structures, it can be used in any water area. is there. In the present system 1, the photosynthetic microorganisms used for the tubular body 2 normally live in an anaerobic environment, and it is necessary to pump water below the pycnocline satisfying the habitat conditions. It is preferable to install the pump 4 and the pumping pipe 5.

A sewage purification method using the sewage purification system 1 configured as described above will be described below. When the tubular body of the present invention is filled with oxygen-deficient or anoxic sewage in the presence of a trace amount of oxygen, photosynthetic bacteria, which are one of the photosynthetic microorganisms, adhere to the inner wall surface of the tubular body of the present invention. Next, the sewage purification tubular body 2 having photosynthetic bacteria attached to the light-bearing layer (near the surface layer) is placed on the floating body 3. Then, anaerobic water (bottom layer water) to be treated is moved into the tubular body 2 by using the pump 4. At this time, oxygen is supplied into the tubular body 2 by diffusion due to the concentration gradient of the oxygen concentration on the outer side and the inner side of the tubular body 2. The trace amount of oxygen supplied to the inner wall of the tubular body 2 by diffusion is utilized for metabolic activity (photosynthesis) of photosynthetic bacteria.
At this time, the photosynthetic bacteria attached to the inner wall of the tubular body 2 ingest the pollutants in the treated water flowing in the tubular body 2.
That is, the photosynthetic action of the photosynthetic bacteria attached to the inner wall surface assimilates and absorbs pollutants such as phosphorus, nitrogen, and heavy metals contained in water, and purifies the water quality. As a result,
The pollutants of the treated water are removed and retained in the living body of photosynthetic bacteria attached to the inner wall of the tubular body 2. By collecting the tubular body 2, the removal of pollutants from the target water (water area) is completed. Since the photosynthetic bacteria adhere to the inner wall of the tubular body 2, it is possible to prevent the pollutants from returning to the treated water.

Thus, phosphorus, nitrogen, and heavy metals are accumulated in high concentration on the inner wall surface of the tubular body 2, which is a very advantageous means from the viewpoint of resource recovery. Further, the dissolved pollutants in the eutrophic water are assimilated and absorbed by the photosynthetic bacteria, so that the photosynthetic bacteria efficiently assimilate the substances, and the most efficient water purification and resource recovery are performed. There is no generation of sludge or slurry, and there is no burden of secondary pollution and recovery processing due to these, so it is excellent in usability.

[0028]

The present invention will be described in more detail with reference to the following examples, but these examples are merely illustrative and do not limit the present invention, and may be modified without departing from the scope of the present invention. Good. In this example, as a basic research toward the construction of a new water purification system, the water purification ability such as the wall adhesion amount of the tubular body of photosynthetic microorganisms, nutrient salt absorption rate, the material of the tubular body, the flow rate, the light conditions, the nutrient salt The quantification of the relationship with environmental conditions such as concentration was confirmed.

Example 1 A laboratory experiment of a continuous culture system quantified the nutrient uptake ability of photosynthetic bacteria. The experimental apparatus is shown in FIG. The present experimental apparatus is a continuous culture system in which the water supplied to the sample core 25 by the perister pump 28 and the water directly above the sample core 25 are sent to the sample bottles for DO measurement and various dissolved substance concentration measurements. There is. The entire device was covered with a thick black curtain-like cloth, leaving the sample core 25 in a pitch dark state. This is because the site where the mud has been collected is pitch-black, so that it matches the situation at the site. Here, the sample core 25 is a pipe made of acrylic resin having an inner diameter of 8.5 cm and containing mud sampled from the site, and is composed of a deposit portion and a direct water portion. By using the acrylic pipe containing mud together, it becomes possible to simulate the water in the form of sediment on site. On the other hand, Tygon tube 31 (trade name; manufactured by Norton) with photosynthetic bacteria attached to the inner wall
Was installed in the horizontal portion of the line connecting the respective upper ends of the sample core 25 or the reference core 26 and the pump 28.
The main feature of this experimental device is that the water quality conditions (DO concentration, pH, etc.) of the water flowing in the tube 31 can be kept steady, and only the effects of specific environmental conditions should be extracted and investigated. You can

The sample is Lake Nakaumi located in the eastern part of Shimane Prefecture.
The sediment and bottom water collected from the heart were used. To supply water
Is bottom water that has been suction filtered using Whatman GF / C.
The DO concentration was adjusted to 0 mg / l by nitrogen aeration and used.
As the experimental condition, the deposit portion of the sample core 25 is dark.
Conditions, about 29 ℃ in the constant temperature water tank 30, tube 31 part
Was light conditions and room temperature. In addition, the development and proliferation of photosynthetic bacteria
In order to ensure that the The result
This is shown in FIGS. From Figure 4 and Figure 5, the feed water has a high concentration.
Contains nutrient salts (PO_Four ^-3-P is about 75μ
g / l, NH_Four ⁺-N is about 150 μg / l), in the effluent
It can be seen that the nutrient concentration of
_Four ^-3-P is about 45 μg / l, NH _Four ⁺-N is about 20μ
g / l). This is a red sulfur fine particle adhering to the inner wall of the tube.
It is considered to be the result of ingestion by photosynthesis performed by the bacterium. This
As shown in FIG.
Information such as salt intake rate was obtained. Also, there is no deposit
Photosynthetic bacteria can develop and grow even under conditions
The result was obtained. Unit is calculated by the following formula (1) (Equation 1)
Calculate the nutrient uptake rate by red sulfur bacteria per area
It was

[0031]

[Equation 1] (In the formula, R is the nutrient salt intake rate per unit area by the red sulfur bacterium, A is the tube inner area, C _in is the nutrient concentration _in the supplied water, C _out is the nutrient concentration in the outflow water, and Q is the flow rate. )

As a result, the PO ₄ ^-3- P intake rate was about 1
0 mg / m ² / day, NH ₄ ⁺ -N intake rate is about 31
It was estimated to be mg / m ² / day. However, the amount of elution from the sediment is not considered in this calculation process,
Considering that the concentration of effluent is extremely low and is disadvantageous for nutrient intake, it is likely that the true nutrient intake rate is underestimated. Taking into account the Reynolds number based on the above results, a simple calculation of the annual water treatment capacity when using 10 tubes with a diameter of 30 cm and a length of 10 m is about 800.
It becomes 0 m ² / yr.

Example 2 An oxygen permeation experiment for determining the oxygen permeation coefficient of various tubes in air was conducted indoors. The tubes used in this example are vinyl (polyvinyl chloride) tubes, silicone (SR) tubes, Toaron tubes (trade name: manufactured by Toa Kagaku), and Tygon tubes (trade name: manufactured by Norton).
I went there. In addition, Toaron tube is PVC and chlorinated P
E, a graft polymer of methyl methacrylate is thermally fused. The tube has an inner diameter of 4 mm, an outer diameter of 6 mm, and a wall thickness of 1 mm. The dissolved oxygen (DO) permeation coefficient k was calculated using the following equation (2) (Equation 2).

[0034]

[Equation 2] (In the formula, C _out is the DO concentration in the outflow water, C _in is the DO concentration _in the inflow water, C _sat is the saturated DO concentration, and C is the DO concentration in the tube that is the target of the DO permeation (the average of the outflow water and the inflow water. (Concentration), L is the wall thickness of the tube, A is the area of the tube that is the target of DO permeation, and Q is the flow rate).

The DO permeability coefficient is shown in Table 1 when each tube is present in air at room temperature of about 15 ° C. From Table 1, it was found that they were a vinyl tube, a Toaron tube, a Tygon tube, and an SR tube in ascending order of oxygen transmission. Especially, the oxygen permeability of the SR tube was remarkably high.

Example 3 The DO permeability coefficient is shown in Table 1 (Table 1) when each tube was immersed in water (DO concentration was saturated) at about 13 ° C. From Table 1, it was found that they were a vinyl tube, a Tygon tube, a Toaron tube, and an SR tube in ascending order of oxygen permeability. Especially, the oxygen permeability of the SR tube was remarkably high. Compared with Example 2, the order of the Tygon tube and the Toaron tube was interchanged. Small values were obtained for Tygon tubes and SR tubes, large values for Toaron tubes, and equivalent values for vinyl tubes, but no significant difference was observed. From Examples 2 and 3, comparing the case where the tube is in water and the case where the tube is in air, the DO permeation coefficient does not change so much. Therefore, when designing a water purification facility using photosynthetic bacteria, it is considered possible to install the tube either in air or in water.

Example 4 When each tube is immersed in water (DO concentration is saturated) at about 20 ° C., the DO permeability coefficient is shown in Table 1 (Table 1). From Table 1, it was found that they were a vinyl tube, a Toaron tube, a Tygon tube, and an SR tube in ascending order of oxygen transmission. Especially, the oxygen permeability of the SR tube was remarkably high. Compared with Example 3, the order of the Tygon tube and the Toaron tube was exchanged. A large value was obtained except for the Toaron tube. From Examples 3 and 4, it can be seen that when the tube is in water, the DO permeation coefficient increases as the water temperature increases except for the Toaron tube.

Example 5 When each tube is immersed in water (DO concentration is saturated) at about 30 ° C., the DO permeability coefficient is shown in Table 1 (Table 1). From Table 1, it was found that they were a vinyl tube, a Toaron tube, a Tygon tube, and an SR tube in ascending order of oxygen transmission. Especially, the oxygen permeability of the SR tube was remarkably high. Compared with Example 3, the order of the Tygon tube and the Toaron tube was exchanged. 12 ° C
It was in the same order as it was in -14 ° C water. Greater values were obtained in all tubes than when the water temperature was low.

[0039]

[Table 1]

From Examples 3 to 5, no significant increase in DO permeation coefficient with increasing water temperature was observed except for the Toaron tube. But for other tubes,
It was observed that the DO permeation coefficient tends to increase as the water temperature increases. From Examples 2 to 5, it is understood that the silicone tube has the highest DO permeation coefficient, and the highest water purification ability (by photosynthetic bacteria) is likely to be exhibited under the appropriate environmental conditions. In the case of the silicone tube, the DO permeation coefficient increased as the water temperature increased. The metabolic activity of photosynthetic bacteria often reaches its maximum around 30 ° C (30 ° C is the optimum growth temperature for R. spheroides. See "Environmental conservation with photosynthetic bacteria" (Tatsuharu Kobayashi)). From the above, it is understood that under the condition that the water temperature is 30 ° C or lower (the seawater in the environment is considered to be the water temperature of 30 ° C or lower), there is a high possibility that the water purification capacity will increase with the increase of the water temperature.

[0041]

EFFECTS OF THE INVENTION According to the sewage purification tubular body of the present invention, a polluted water mass enriched in eutrophication, anoxia or anoxia is passed through a tubular body grown with adhering photosynthetic bacteria,
By promoting photosynthesis, it is possible to easily and simply remove pollutants contained in the water mass and collect useful resources, and to construct a new water purification system. Moreover, since the photosynthetic bacteria can be attached thinly and widely to the inner wall surface of the tubular body, it is possible to uniformly apply various conditions such as light, oxygen supply, and nutrient supply to the entire photosynthetic bacteria. In addition, if one optimal condition is prepared, the condition will be distributed to all individuals, so it becomes easy to give optimal conditions to all photosynthetic bacterial individuals, and the water purification ability of the photosynthetic bacteria to be retained is maximized. It is possible to withdraw the limit. In addition, since the photosynthetic bacteria that perform water treatment spread thinly on the inner wall of the tubular body, it is possible to easily dehydrate by draining the water inside the tubular body without generating a large amount of sludge, which requires a large amount of equipment, cost and labor. Does not need Furthermore, since it can be easily installed in the water area of the site, does not require long-distance transportation of water, and uses natural light, it does not require a large amount of energy input, and can be easily and sufficiently coped with, for example, solar power generation.

According to the sewage purification method of the present invention, it is possible to purify an eutrophic water area at low cost and with low energy. Also, the necessary artificial energy is only to transfer the bottom layer water to the light layer (near the surface layer),
It can be operated with very little energy input.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a wastewater purification system in the present embodiment.

FIG. 2 is a schematic view of a main part of the wastewater purification system according to the present embodiment.

FIG. 3 is a schematic diagram of a continuous culture system experimental apparatus in Example 1 of the present invention.

FIG. 4 is a graph showing nutrient uptake ability (PO ₄ ^-3- P) of photosynthetic bacteria in Example 1 of the present invention.

FIG. 5 is a graph showing nutrient uptake ability (NH ₄ ⁺ −N) of photosynthetic bacteria in Example 1 of the present invention.

[Explanation of symbols]

1 Sewage purification system 2 Tubular body for purifying sewage 3 floating body 4 Pumping pump 5 pumping pipe 6 wires 8 water supply pipe 9 weights 10 anchor 11 valves 12 solar power generator A density layer 21 DO meter 22 Supply tank (1) 22 'Supply tank (2) 23 Oxygen cylinder 24 nitrogen cylinder 25 sample cores 26 Reference Core 27 DO meter 28 pumps 29 stirrer 30 constant temperature water tank 31 tubes

Claims (10)

[Claims] 1. A pipe for purifying sewage, characterized in that at least a part of the inner wall surface has a photosynthetic microorganism adhering ability, and is composed of a tubular body capable of photosynthesis by passage of sewage that has been deoxidized or deoxygenated. body. 2. The tubular body for purifying wastewater according to claim 1, wherein at least a part of the inner surface of the tubular body is a polymer having photosynthetic microorganism adhering ability and light transmitting ability. 3. The sewage purification tubular body according to claim 2, wherein the polymer has gas permeability. 4. The tubular body for purifying sewage according to claim 2 or 3, wherein the polymer is at least one selected from polytetrafluoroethylene, polyvinyl chloride, and silicone resin. 5. The sewage purification tubular body according to any one of claims 1 to 4, wherein the tubular body has a circular cross section, a polygonal cross section, or a combination thereof. 6. A method for purifying sewage, characterized in that the sewage deoxidized or deoxygenated is passed through the tubular body according to any one of claims 1 to 5 in the presence of a trace amount of oxygen. . 7. After attaching photosynthetic microorganisms to the tubular body,
7. Sewage is passed through the tubular body.
The sewage purification method described in. 8. The method for purifying sewage according to claim 6 or 7, wherein after the sewage is purified, the valuable substances attached to the tubular body are recovered. 9. The wastewater purification method according to claim 8, wherein the valuable resource is a phosphorus-containing material. 10. The sewage purification method according to any one of claims 6 to 9, wherein the sewage is anaerobic sewage.