Biological treatment apparatus using nanobubbles

Abstract

To provide a biological treatment apparatus using nanobubbles that utilizes oxygen nanobubbles in sewage treatment using biodegradation treatment by bacteria to efficiently perform sewage treatment.SOLUTION: A biological treatment apparatus using nanobubbles includes: a raw water tank to which sewage from homes and factories is discharged, and which settles and removes solid matters included in the sewage; an aeration tank to which the sewage from which the solid matters included in the sewage is removed by the raw water tank is supplied, and which performs biodegradation by bacteria to purify the sewage; nanobubble generating means which supplies oxygen-nanobubble water to the aeration tank, supplies a large amount of oxygen to the bacteria, and assists biodegradation treatment of the sewage by the bacteria; and an electrolysis treatment tank which performs sterilization treatment of liquid subjected to purification treatment by the bacteria in the aeration tank.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a biological treatment apparatus using nanobubbles, which uses biodegradation by bacteria in sewage treatment, utilizes oxygen nanobubbles, efficiently performs sewage treatment, and performs more environmentally friendly sewage treatment without increasing the size of the apparatus.

Background Art

[0002] Regarding nanoscale microbubbles, research on their physical properties, generation mechanisms, specific applications, and their practical implementation has been rapidly progressing. For example, research has been conducted on the cultivation of aquatic organisms using fine bubble-containing water containing nano-order microbubbles, and supplying fine bubble-containing water to paddy fields to improve water quality. Currently, research on the purification treatment of sewage and sterilization in particular has attracted attention.

[0003] Conventionally, for the purification treatment of sewage, sewage from homes and factories discharged through drain pipes is put into a raw water tank, solid matter in the sewage is precipitated and removed at the bottom of the raw water tank, and the sewage from which the solid matter has been removed is sent to an aeration tank, where it is biodegraded and purified by bacteria such as amoeba and pill bugs in the aeration tank and then discharged.

[0004] The invention of Patent Document 1 proposes a method for removing carbon and nitrogen pollutants in sewage using bacteria. This method is based on the physiological characteristics of bacteria and the metabolic principle of the combined oxidation of carbon and nitrogen, and performs ideal purification treatment in a temperature range of, for example, 6°C to 40°C, and does not require the discharge of sludge during the removal process.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the invention described in Patent Document 1, a device for controlling the aeration tank to a predetermined temperature is required, and the equipment becomes large-sized. Further, in the invention described in Patent Document 1, it is necessary to use a chemical such as a sodium phenolate solution, and it is impossible to perform sewage treatment without using any chemicals.

[0007] Therefore, the present invention utilizes oxygen nanobubble water during sewage treatment by biodegradation using bacteria, efficiently purifies sewage, enables large-capacity sewage treatment without increasing the size of the device, and provides a biological treatment device using nanobubbles that is environmentally friendly without using any chemicals.

Means for Solving the Problems

[0008] According to the present invention, the above problems can be achieved by providing a biological treatment device using nanobubbles, which includes a raw water tank for discharging sewage from homes and factories and removing precipitated solids contained in the sewage, an aeration tank supplied with the sewage from which the solids contained in the sewage have been removed by the raw water tank, and performing biodegradation by bacteria to purify the sewage, an oxygen nanobubble water generation means for supplying oxygen nanobubble water to the aeration tank, supplying a large amount of oxygen to the above bacteria, and efficiently performing the biological decomposition treatment of sewage by the bacteria, and an electrolysis treatment tank for performing sterilization treatment of the liquid purified by the bacteria in the above aeration tank.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an overall configuration diagram of a biological treatment apparatus using nanobubbles according to this embodiment. In the figure, 1 is a raw water tank into which raw sewage 2 from homes and factories is discharged. For example, sewage containing feces and urine is discharged from homes, and oxygen-consuming pollutants such as various organic carbons, nitrogen, inorganic nitrogen, and phosphorus are discharged from factories.

[0011] The raw water tank 1 has a solid-liquid separation function, and the solids contained in the sewage 2 settle to the bottom of the raw water tank 1 as sediment 3, and the solids contained in the sewage 2 are removed. Further, the sewage (liquid) 4 from which the solids have been removed is sent to the next aeration tank 5. Incidentally, the sediment 3 accumulated at the bottom of the raw water tank 1 is treated as industrial waste together with the sediment 6 discharged in the next step.

[0012] In the aeration tank 5, aerobic bacteria 7 such as amoeba, pill bugs, and earwigs are present, which decompose nitrogen, phosphorus, etc. contained in the sewage and perform purification treatment of the sewage. Also, this aerobic bacteria requires a large amount of oxygen for the decomposition treatment. Therefore, in the present invention, oxygen nanobubble water is supplied to this aeration tank 5.

[0013] FIG. 2 is a diagram for explaining an oxygen nanobubble water generator that supplies oxygen nanobubble water to the aeration tank 5. In the figure, the oxygen nanobubble water generator 8 used in this embodiment is composed of a liquid input pipe 9, an aspirator 10, a gas supply unit 11, and a discharge pipe 12.

[0014] Pressurized liquid (hereinafter referred to as water) is vigorously supplied to the liquid input pipe 9 using a pump (not shown), etc., and blades 9a for generating a swirling flow are provided in the liquid input pipe 9. As shown in FIG. 2, the diameter of the tip 10a of the aspirator 10 is small, and it is configured to increase the flow velocity of the supplied water flow. The aspirator 10 creates a decompressed state by utilizing this water flow and the Venturi effect.

[0015] The gas supply unit 11 supplies oxygen to the apparatus 8. For this purpose, the gas supply unit 11 is provided with a through hole 11a through which oxygen passes, and the tip of this through hole 11a communicates with an air supply port 12a provided in the discharge pipe 12. This position is a region that becomes a negative pressure state due to the high-speed water flow, and the supplied oxygen is automatically sucked from the air supply port 12a.

[0016] A groove 13 is provided on the inner peripheral surface of the discharge pipe 12. The water flow near the peripheral surface of the discharge pipe 12 rotates at high speed. The bubbles broken by the swirling flow further collide with the groove 13 to become fine bubbles, and the water containing fine bubbles is discharged from the discharge pipe 12.

[0017] That is, the oxygen sucked into the discharge pipe 3 becomes bubbles due to the gas-liquid mixing effect, is broken by the high-speed swirling flow, and becomes fine bubbles and flows in the discharge pipe 12. At this time, the bubbles flowing outside the water flow collide with the groove 13 formed on the peripheral surface of the discharge pipe 3, the bubbles are further broken, and nano-level bubbles containing oxygen are generated.

[0018] In this way, the bubbles mixed in the swirling flow are nano-order fine bubbles, and are discharged from the discharge pipe 12 as water containing fine bubbles into the aeration tank 5.

[0019] When the nano-bubble water containing oxygen is supplied to the aeration tank 5, the decomposition treatment of nitrogen, phosphorus, etc. contained in the sewage by the bacteria 7 is activated.

[0020] Figure 3 is a diagram schematically showing this state. As shown in the figure, bacteria such as amoeba and pill bugs perform the purification treatment of the sewage discharged into the aeration tank 5 by biodegradation treatment, and aerobic bacteria particularly require a large amount of oxygen for the decomposition treatment. Therefore, when the oxygen concentration decreases, an oxygen-deficient state occurs and the sewage treatment function deteriorates.

[0021] Here, when fine bubbles containing oxygen are supplied from the oxygen nano-bubble water generator 8 to the aeration tank 5 as described above, the biodegradation function of the bacteria 7 is activated and the purification function is promoted.

[0022] Furthermore, the nanobubble water supplied from the nanobubble generator 8 contains a large amount of fine bubbles, further improving the purification function of the sewage and enabling more efficient purification treatment.

[0023] In addition, since a large amount of oxygen is supplied, sewage treatment can be efficiently performed without using any chemicals, and a biological treatment device using nanobubbles that is more environmentally friendly can be obtained.

[0024] When the sewage is biodegraded in this way, solids precipitate as sediment 6 at the bottom of the aeration tank 5. This residue (sediment 6) and the sediment 3 discharged in the previous process as described above are both treated as industrial waste.

[0025] The sewage that has undergone decomposition treatment in the aeration tank 5 is sent to the oxidation-reduction tank 12 and sterilized by electrolysis. FIG. 4 is a schematic diagram of the oxidation-reduction tank 14. For example, the positive electrode (+) 15 is made of aluminum or the like, and the negative electrode (-) 16 is made of stainless steel (SUS) or the like. The purified water biodegraded by the aeration tank 5 is passed through this oxidation-reduction tank 14 for sterilization treatment.

[0026] As described above, according to the present invention, by using oxygen nanobubble water, sewage treatment by biodegradation using bacteria can be efficiently performed, large-capacity sewage treatment can be enabled without increasing the size of the device, and a biological treatment device using nanobubbles that is environmentally friendly without using any chemicals can be provided.

[0027] In addition, in the description of this embodiment, the case where aerobic bacteria 7 such as amoeba, pill bugs, and earwigs are present in the aeration tank 5 has been described. However, when anaerobic bacteria are used for sewage purification, nitrogen is supplied to the aeration tank 5 in order to promote the biodegradation function of the anaerobic bacteria present in the aeration tank 5.

[0028] In this case, instead of the oxygen nanobubble water generator 8 shown in FIG. 2, a nitrogen nanobubble water generator (not shown) is used. That is, nitrogen is supplied from the gas supply unit 11, and the nitrogen sent through the through-hole 11a is sucked into the discharge pipe 3, becomes bubbles due to the gas-liquid mixing effect, is crushed by a high-speed swirling flow, becomes fine bubbles, and becomes nanolevel bubbles containing nitrogen, and is configured to be supplied to the aeration tank 5.

[0029] 1···Raw water tank 2···Sewage 3···Sediment 4···Sewage (liquid) 5···Aeration tank 6···Sediment 7···Bacteria 8···Oxygen nanobubble water generator 9···Liquid input pipe 9a···Blade 10···Aspirator 10a···Tip 11···Gas supply unit 11a···Through-hole 12···Discharge pipe 12a···Air supply port 13···Groove 14···Oxidation-reduction tank 15···Positive electrode (+) 16···Negative electrode (-)

Claims

1. A raw water tank that discharges sewage from homes and factories and precipitates and removes solids contained in the sewage, An aeration tank that is supplied with sewage from which solids contained in the sewage have been removed by the raw water tank, and that purifies the sewage by biodegradation by bacteria, Nanobubble generation means that supplies oxygen nanobubble water to the aeration tank, supplies a large amount of oxygen to the bacteria, and assists the biodegradation treatment of the sewage by the bacteria, A biological treatment apparatus using nanobubbles, characterized by comprising the above.

2. A raw water tank that discharges sewage from homes and factories and precipitates and removes solids contained in the sewage, An aeration tank that is supplied with sewage from which solids contained in the sewage have been removed by the raw water tank, and that purifies the sewage by biodegradation by aerobic bacteria, Nanobubble generation means that supplies oxygen nanobubble water to the aeration tank, supplies a large amount of oxygen to the bacteria, and assists the biodegradation treatment of the sewage by the bacteria, An electrolysis treatment tank that performs sterilization treatment on the liquid purified by the bacteria in the aeration tank, A biological treatment apparatus using nanobubbles, characterized by comprising the above.

3. The biological treatment apparatus using nanobubbles according to claim 1 or 2, wherein the bacteria are aerobic bacteria.

4. The biological treatment apparatus using nanobubbles according to claim 1 or 2, wherein the bacteria are anaerobic bacteria.

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