Wastewater treatment methods

Abstract

The object of the present invention is to provide a method for treating wastewater that involves a new process of ionizing the wastewater by generating the Leonard effect through high-pressure movement of the wastewater. [Solution] A method for treating wastewater (0) comprising an aeration process and a sedimentation process in which sediment is removed using a sedimentation tank (5), in which a refinement process is provided before the aeration process in which oil and organic matter in wastewater (0) containing organic matter and oil is refined. In the refinement process, a refinement device (7) is used, and air is mixed into the wastewater sent at high pressure by an ejector (9) in the direction of arrow X, thereby pulverizing the organic matter and oil in the wastewater (0) by the ejector effect, and at the same time, the high-pressure movement of the wastewater (0) generates a Lenard effect, ionizing the wastewater (0).

Description

[Technical Field]

[0001] The present invention relates to a method for treating wastewater by utilizing aerobic bacteria in the purification of wastewater contaminated with organic matter, mineral oil, vegetable oil, etc. [Background technology]

[0002] In factories and other places that use water, a commonly used method for purifying wastewater contaminated with organic matter, mineral oil, vegetable oil, etc. is to treat the contaminated water by subjecting the water to aerobic bacteria, etc., and allowing the bacteria to grow and digest the contaminated components. In such wastewater treatment methods, it is said that a hydraulic retention time of about 10 hours is required for wastewater containing a high concentration of oil (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6157860 Summary of the Invention [Problem to be solved by the invention]

[0004] Such conventional wastewater treatment methods require a hydraulic retention time of approximately 10 hours due to bacterial growth and other reasons, which means that large-scale treatment equipment (number of tanks, capacity, etc.) is required to treat the required wastewater, and this is not necessarily optimal for the purpose of efficient wastewater treatment.

[0005] The present invention has been made in consideration of the above problems, and aims to provide a method for treating wastewater that can reduce the required hydraulic retention time to at least 3 hours by adding a micronization process that micronizes oil and organic matter in wastewater containing organic matter and oil before the aeration process that promotes bacterial growth, and by passing through a new process that generates the Lenard effect by moving the wastewater under high pressure to ionize the wastewater. [Means for solving the problem]

[0006] The wastewater treatment method of the present invention, which solves these problems, uses an aeration tank in which aeration is performed in an activated sludge tank where aerobic treatment is performed using bacteria, and a settling tank, and includes an aeration treatment process in which the aerobic treatment using bacteria is performed in the aeration tank for a predetermined residence time, and a settling process in which sediment is removed using the settling tank.The method includes a micronization process, which micronizes the oil and organic matter in the wastewater containing organic matter and oil, before the aeration treatment process, and the micronization process uses a pump to transport the wastewater, mixing air into the wastewater using the ejector effect to pulverize the organic matter and oil, and also ionizes the wastewater by generating a Lenard effect due to the high pressure movement of the wastewater.

[0007] Furthermore, in the above wastewater treatment method, the atomization step is a step of causing the wastewater to collide with a plurality of blades by the pump to obtain the Lenard effect. [Effects of the Invention]

[0008] According to the present invention, an object of the present invention is to provide a method for treating wastewater which includes a micronization step and a new step of ionizing the wastewater by generating the Leonard effect through high-pressure movement of the wastewater, thereby micronizing the oil and organic matter in the wastewater and promoting the ionization of water particles, making it easier to maintain the oil and organic matter in a micronized state, promoting biodegradation through aerobic treatment by bacteria, and enabling aerobic treatment to be carried out efficiently, thereby reducing the required hydraulic retention time. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an explanatory diagram of the overall configuration of a wastewater treatment device used in the first embodiment of the present invention. [Figure 2] A side view of the micro-finishing device used in the micro-finishing process of the device. [Figure 3]FIG. 1 is an explanatory diagram showing the effect of finely pulverizing wastewater by the finely pulverizing step according to the first embodiment of the present invention. [Figure 4] FIG. 1 is a cross-sectional side view of an aeration tank used in the first embodiment of the present invention. [Figure 5] FIG. 1 is a cross-sectional side view of an aeration unit used in the first embodiment of the present invention. [Figure 6] FIG. 1 is a front view of a micronization unit used in a micronization process according to a first embodiment of the present invention; [Figure 7] Left side view of the same microfabrication unit [Figure 8] Right side view of the same microfabrication unit [Figure 9] FIG. 1 is a partial cross-sectional view of the main part of the micro-fining device. [Figure 10] FIG. 1 is a perspective view of a cylindrical body of an aeration unit used in the first embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram of a wastewater treatment device used in the first embodiment of the present invention. Wastewater 0 contaminated with organic matter, mineral oil, vegetable oil, etc. in water-using factories and other facilities is stored in raw water tank 2, where solids are removed using screen 3 and stored in adjustment tank 4 before being sent to aeration tank 1, where aerobic bacteria are used to propagate and digest the contaminated components. Adjustment tank 4 adjusts the amount of wastewater sent to aeration tank 1 to match the aeration tank's wastewater purification treatment capacity. Wastewater 0 is sent to aeration tank 1 and undergoes an aeration treatment process, where it is treated aerobically with bacteria for a specified residence time. After the aeration treatment process, wastewater 0 goes to sedimentation tank 5, where sediment 6 is removed. The treated water separated from sediment 6 is confirmed to meet specified wastewater standards and then discharged or reused.

[0011] Conventional aeration processes require a hydraulic retention time of approximately 10 hours to prevent bacterial growth and other problems. However, the first embodiment of the present invention improves this by providing a refinement process for refining oil and organic matter in wastewater. The refinement process will now be described. FIG. 2 is a side view of a refinement device 7 used in the refinement process. In the first embodiment, the refinement device 7 is installed parallel to the adjustment tank 4. The wastewater stored in the adjustment tank 4 is pumped to the refinement device 7 by a pump 8. In this refinement process, the pump 8 sends wastewater to an ejector 9. The ejector 9 mixes the wastewater, which is sent under high pressure in the direction of arrow X, with air from an air inlet 10 installed above. This ejector effect breaks down the organic matter and oil in the wastewater. The high-pressure movement of the wastewater also creates a Lenard effect, ionizing the wastewater. These steps constitute the refinement process. In the micronization process using the micronization device 7, the Leonard effect is enhanced by using a micronization unit 100, which will be described in detail later.

[0012] 3 shows measurement results indicating that wastewater is refined by the refinement process in embodiment 1 of the present invention (values ​​without using the refinement unit 100), in which the turbidity of the treated water (wastewater) changes over the course of treatment time, and after two hours of treatment, the turbidity approaches a constant level at saturation, demonstrating that the refinement process has achieved the desired effect (the values ​​on the vertical axis of FIG. 3 indicate the values ​​of the MLSS concentration meter, with the solid line representing the measurement results of embodiment 1 and the dotted line representing the measurement results without the refinement process for comparison). The increase in turbidity indicates that organic matter, mineral oil, vegetable oil, etc. in the water to be treated have been refined and are floating in the water instead of settling.

[0013] Next, the aeration tank 1 used in the first embodiment of the present invention will be described. FIG. 4 is a side cross-sectional view of the aeration tank 1. After a process for reducing oil and organic matter in the wastewater, the wastewater is supplied to the inlet 11 of the aeration tank 1 by a pump (not shown). The amount of wastewater supplied is adjusted by adjusting the operation of the pump to match the processing capacity of the aeration tank 1. The reduced wastewater is then supplied from the inlet 11 to the aeration unit 13 via a pipe 12. As will be described later, the aeration unit 13 uses air pump 14 to supply pressurized air to the wastewater containing the reduced oil and organic matter, and an aeration process is carried out in which bacteria in the aeration tank 1 aerate for a predetermined retention time. After a predetermined retention time and the aeration process, the treated water flows out of the outlet 15 and is introduced into the sedimentation tank 5, completing the wastewater treatment process. The bacteria in the aeration tank 1 are naturally present in the aeration tank 1, but they may also be supplied separately.

[0014] Next, the aeration unit 13 will be described. FIG. 5 is a side cross-sectional view of the aeration unit 13 used in the first embodiment of the present invention. The aeration unit 13 is disposed above an air outlet 102 connected to an air supply source (not shown) of an air pump 14. The aeration unit 13 is fixed and supported by fixtures 104 in an aeration tank 1 that stores a liquid such as wastewater, and is used in the liquid such as wastewater. The aeration unit 13 is configured by stacking multiple cylinders 107 in the axial direction of the cylinders. Each cylinder 107 is made of a cylindrical frame 105 (see FIG. 10) and multiple protrusions 106 (see FIG. 10) protruding toward the center from the frame 105. The cylinders 107 are made of resin and are fixed to each other by ultrasonic welding. When air is supplied in the direction of arrow R from the air pump 14, the air and wastewater collide with the protrusions 106 of the cylinders 107, further reducing the size of the bubbles and oil, thereby enabling more efficient decomposition of the oil by bacteria and the like.

[0015] Next, we will explain the micronization unit 100 used in the micronization device 7 used in the micronization step. The micronization unit 100 is configured by sharing a cylindrical frame 105 (see Figures 7 and 10) used in the aeration unit 13 and a columnar body 107 consisting of a plurality of protrusions 106 (see Figures 7 and 10) protruding from the frame 105 toward the center. In the micronization unit 100, wastewater is sent to the ejector 9, and in the ejector 9, air is mixed into the wastewater sent at high pressure in the direction of arrow X from an air port 10 provided above, and the organic matter and oil in the wastewater are pulverized by the ejector effect, and further, by placing the micronization unit 100 at the destination of the wastewater, the high-pressure movement of the wastewater enhances the Lenard effect.

[0016] The micronization unit 100 (cylinder 107) will be further described with reference to Figures 7 to 9. The micronization unit 100 (cylinder 107) is composed of a cylindrical frame 105 and a plurality of protrusions 106 protruding from the frame 105 toward the center, and the protrusions 106 of the cylinder 107 are set to a predetermined length so that they face each other at the center and form openings 111 for generating cavitation. The plurality of protrusions 106 have radial grooves 112 formed on the upper surface (downstream side in the direction of the air and water currents (arrow X)) that are U-shaped in circumferential cross section and open upward (i.e., the grooves 112 are formed in the length direction of the protrusions 106).

[0017] Furthermore, groove 112, which is U-shaped in circumferential cross section, has an additional deep groove 113 at the groove bottom. Groove 112 and deep groove 113 are formed so as to open toward the downstream side in the direction of the air current and water current (arrow X), and are shaped to form Karman vortices (shown by arrow K in FIG. 9). The formation of Karman vortices K applies shear force to the oil and grease and air bubbles in the wastewater, further reducing the size of the oil and grease and air bubbles (experiments have confirmed that particle sizes become 3 to 7 microns).

[0018] Furthermore, the plurality of protrusions 106 are provided with a pair of stepped collision surfaces 116 on the left and right sides of the lower surface of the protrusions 106 in the longitudinal direction of the protrusions 106, the pair being perpendicular to and facing the wastewater (arrow X) ejected from the ejector 9, with the step tip 117 at the center. The stepped collision surfaces 116 are provided in pairs on the left and right sides of the step tip 117, each having three collision surfaces 118. In the first embodiment, the U-shaped cross-sectional groove 112 and the plurality of collision surfaces 118 are provided on the upper and lower surfaces of the same protrusions 106, but a selective arrangement in which only the stepped collision surfaces 116 are provided is also possible through appropriate design, and can be changed to suit the required ability to refine grease and bubbles.

[0019] The plurality of protrusions 106 are provided with a plurality of stepped collision surfaces 116 that are perpendicular to and face the wastewater (arrow X) ejected from the ejector 9, thereby further enhancing the Lenard effect. One atomization unit 100 is provided at the tip of the ejector 9, but a plurality of units may be provided in the direction of the wastewater flow.

[0020] In the first embodiment, the micronization device 7 is provided in parallel with the adjustment tank 4, but in another embodiment, the micronization device 7 may be placed inside the adjustment tank 4, or the adjustment tank 4 may be placed before the adjustment tank 4. Also, the adjustment tank 4 may be omitted, and wastewater may be supplied from the screen 3 to the aeration tank 1 by a pump or the like. [Industrial Applicability]

[0021] The present invention enables efficient purification of wastewater and is therefore widely applicable to the treatment of wastewater generated in paint factories, machining equipment, paper mills, factories handling chemical substances, and the like. [Explanation of symbols]

[0022] 1 aeration tank 4 Adjustment tank 5 Sedimentation tank 7 Microfabrication equipment (microfabrication process) 13 Aeration unit 100 Micronization Unit

Claims

1. an aeration tank for aeration in an activated sludge tank for aerobic treatment using bacteria; A settling tank is used, After an aeration treatment step in which the aerobic treatment by the bacteria is performed in the aeration tank for a predetermined retention time, A wastewater treatment method comprising a sedimentation step of removing sediment using the sedimentation tank, Before the aeration treatment step, a micronization step is provided in which the oil and organic matter in the wastewater containing the organic matter and the oil are micronized; The pulverization process is a process in which the wastewater is pumped and air is mixed into the wastewater by an ejector effect, and the organic matter and oil are pulverized, and the high-pressure movement of the wastewater causes a Lenard effect to ionize the wastewater. How wastewater is treated.

2. 2. The wastewater treatment method according to claim 1, wherein the micronizing step is a step of causing the pump to impinge the wastewater against a plurality of blades to obtain the Lenard effect.

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