Ecological treatment system for rapidly eliminating black and odorous water body and ecological purification method thereof

Abstract

The present application provides a kind of ecological treatment system for quickly eliminating black and odorous water body and ecological purification method thereof, the ecological treatment system includes super-nano gas solution oxygenation system and dissolved oxygen automatic monitoring system;Super-nano gas solution oxygenation system includes super-nano gas solution equipment and the water inlet pipeline and water outlet pipeline communicated with super-nano gas solution equipment;Dissolved oxygen automatic monitoring system includes several dissolved oxygen automatic monitoring points arranged along the way;Super-nano gas solution equipment is communicated with oxygen generation system;The ecological purification method for quickly eliminating black and odorous water body of the present application is handled to black and odorous water body using the above ecological treatment system, and the purpose of quickly eliminating black and deodorizing is achieved by the way of sufficient reoxygenation to water body, without any chemical agent, microbial inoculant, without causing secondary pollution of water body, without visible bubble, without disturbing water body.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to an ecological treatment system and ecological purification method for rapidly eliminating black and odorous water bodies. Background Technology

[0002] The formation of urban black and odorous water bodies is mainly caused by outdated urban drainage systems. For example, in old urban areas, the mixing, misconnection, and leakage of combined sewer systems can lead to large amounts of domestic sewage overflowing into rainwater systems. This sewage then enters rivers and lakes along with the rainwater, and the high load of organic pollution far exceeds the self-purification capacity of the rivers and lakes, causing an imbalance between oxygen supply and demand in the water. This leads to the rapid proliferation of anaerobic microorganisms, producing large amounts of malodorous gases such as hydrogen sulfide, mercaptans, and ammonia. Simultaneously, the oxidation-reduction potential in the water decreases rapidly, and the Fe... 3+ Reduced Fe 2+ sulfides and Fe 2+ The combination of these substances forms blackening substances, causing the water to become black and smelly, seriously affecting the surrounding ecological environment and reducing citizens' sense of gain and happiness from a beautiful ecological environment.

[0003] Currently, common technologies for treating urban black and odorous water bodies include onshore stormwater and sewage separation projects, initial rainwater storage and treatment, and upgrading and expanding sewage treatment plants, aiming to achieve complete interception and treatment of sewage. However, these methods are costly and difficult to eradicate completely, with the phenomenon of blackening and odor recurring after rain persisting for a long time. Traditional technologies, such as dredging and water diversion, attempt to quickly eliminate blackness and odor. While these methods can solve the problem temporarily, they also have drawbacks such as transferring pollution sources and repeated high-cost engineering projects, making them unsustainable. Existing technologies often use biological and chemical methods such as adding microbial agents, coagulants, and deodorizers to the water, or use artificial floating islands and aquatic plants to eliminate blackness and odor, but the results are minimal, and there is a risk of secondary pollution to the water body.

[0004] Due to the lack of oxygen in black and odorous water bodies, a large number of oxygen replenishment and reoxygenation devices have emerged, such as fountain aeration, micro-nano blower aeration, and push-flow aerator. These methods can quickly eliminate blackness and odor to a certain extent, but they also have some drawbacks, including disturbing the water body, low oxygen utilization and transfer efficiency, and surface aeration being unable to meet the oxygen demand of the bottom. They also have problems such as high operating costs and frequent equipment maintenance and replacement.

[0005] In view of this, it is necessary to design an ecological treatment system and its ecological purification method for rapidly eliminating black and odorous water bodies in order to solve the above problems. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide an ecological treatment system and its ecological purification method for rapidly eliminating black and odorous water bodies. It does not involve the addition of any chemical agents or microbial agents, and will not cause secondary pollution of the water body; it produces no visible bubbles, does not disturb the water body, and can achieve the purpose of rapidly eliminating blackness and odor.

[0007] To achieve the above objectives, the present invention provides an ecological treatment system for rapidly eliminating black and odorous water bodies, comprising an ultra-nano dissolved oxygen reoxygenation system and an automatic dissolved oxygen monitoring system; the ultra-nano dissolved oxygen reoxygenation system includes an ultra-nano dissolved oxygen device, an inlet pipe and an outlet pipe connected to the ultra-nano dissolved oxygen device; the automatic dissolved oxygen monitoring system includes several automatic dissolved oxygen monitoring points set along the pipeline; the ultra-nano dissolved oxygen device is connected to the oxygen generation system through an air inlet pipe.

[0008] As a further improvement of the present invention, the water outlet pipe is divided into multiple branches, which are respectively set at different locations.

[0009] As a further improvement of the present invention, the ultra-nano aerosol device includes a conical aerosol tank, and the formula for calculating the contact radius R of the conical aerosol tank is as follows:

[0010]

[0011] Where R is the contact radius of the conical dissolved gas tank, in meters;

[0012] R1—Radius of the top of the conical dissolved gas tank, in meters;

[0013] R2—Radius of the bottom of the conical dissolved gas tank, in meters;

[0014] h—Height of the conical dissolved gas tank, in meters;

[0015] Z—coordinate;

[0016] The formula for calculating the effective cross-sectional area A of the conical dissolved air tank is as follows:

[0017] A = πR 2 (2)

[0018] Wherein, A—the effective cross-sectional area of ​​the cone-shaped dissolved air tank, m 2 ;

[0019] R—Contact radius of the conical dissolved gas tank, in meters;

[0020] π — Pi (the mathematical constant of a circle).

[0021] The water flow rate V inside the conical dissolved air tank s The calculation formula is:

[0022]

[0023] Among them, V s —Water flow rate, m / s;

[0024] Q w —Water flow rate, m 3 / s;

[0025] A—Effective cross-sectional area of ​​the conical dissolved gas tank, in m² 2 ;

[0026] The formula for calculating the oxygen mass transfer capacity J of the conical dissolved air tank is as follows:

[0027] J = K OL (C s -C0) (4)

[0028] C s =KP i (5)

[0029] Among them, J—the oxygen mass transfer capacity of the cone-shaped dissolved gas tank, mol / (m 2 ·s);

[0030] K OL —Mass transfer coefficient, m / s, related to the oxygen bubble radius r, K OL =0.6r (r < 6.67 × 10) -4 m) or K OL =4×10 -4 (r≥6.67×10 -4 m);

[0031] C s —Saturated dissolved oxygen concentration in water body, mol / m³ 3 ;

[0032] C0—Initial dissolved oxygen concentration in the water body, mol / m³ 3 ;

[0033] K — Henry's constant, mol / (Pa·m) 3 );

[0034] P i —Oxygen pressure at a certain depth, Pa;

[0035] The formula for calculating the residence time t of the oxygen bubbles in the conical dissolved gas tank is:

[0036]

[0037] Where t is the residence time of oxygen bubbles in the conical dissolved gas tank, in seconds;

[0038] k1—bubble rise coefficient, 0.2~0.5, dimensionless;

[0039] h—Height of the conical dissolved gas tank, in meters;

[0040] v b —The rising velocity of the oxygen bubble, m / s; the radius r of the oxygen bubble satisfies r < 7 × 10⁻⁶. -4 m,v b =4474r 1.357 (m / s); 7×10 -4 ≤r<5.1×10 -3 m,v b =0.23 (m / s); r≥5.1×10 -3 m,v b =4.202r 0.547 (m / s);

[0041] The formula for calculating the height h1 of the gas-liquid mixing zone in the conical dissolved gas tank is as follows:

[0042] h1=h-(V s -v b k)t (7)

[0043] Where h1 is the height of the gas-liquid mixing zone in the conical dissolved gas tank, in meters;

[0044] h—Height of the conical dissolved gas tank, in meters;

[0045] V s —Water flow rate, m / s;

[0046] v b —Oxygen bubble rising velocity, m / s;

[0047] k—an empirical parameter, 0.3 to 0.4, dimensionless;

[0048] t — Residence time of oxygen bubbles in the conical dissolved gas container, s;

[0049] The formula for calculating the residence time t1 of the oxygen bubbles in the water outlet pipe is:

[0050]

[0051] Where t1 is the residence time of oxygen bubbles in the water outlet pipe, in seconds;

[0052] Q w —Water flow rate, m 3 / s;

[0053] R3—Inner diameter of the outlet pipe, in meters;

[0054] L—Length of the outlet pipe, in meters;

[0055] π — Pi (the mathematical constant of a circle).

[0056] As a further improvement of the present invention, the length of the water outlet pipe is 10-500m and the diameter is 20-100mm.

[0057] As a further improvement of the present invention, the total residence time of oxygen bubbles in the ultra-nano aerosol device and the water outlet pipe is 60-90 seconds.

[0058] Furthermore, the pressure in the conical dissolved gas tank is 0.4–0.6 MPa.

[0059] As a further improvement of the present invention, the diameter of the water inlet pipe is 300-400 mm.

[0060] The oxygen generation system is either machine-generated oxygen or liquid oxygen in a Dewar flask.

[0061] This invention also provides an ecological purification method for rapidly eliminating black and odorous water bodies, employing the aforementioned ecological treatment system for rapidly eliminating black and odorous water bodies, comprising the following steps:

[0062] S1. Test the water quality and quantity of black and odorous water bodies and calculate the target oxygen demand for black and odorous water bodies;

[0063] S2. Install ultra-nano aerosol equipment at the end of the open channel to be treated, and install inlet and outlet pipes. At the same time, install automatic dissolved oxygen monitoring points along the channel.

[0064] S3. Start the ultra-nano dissolved oxygen device. When the dissolved oxygen in the water begins to rise, set the running time according to the dissolved oxygen content displayed by the automatic dissolved oxygen monitoring point. Start the device when the minimum dissolved oxygen content at the monitoring point is below 6 mg / L, and turn off the device when it is above 12 mg / L.

[0065] As a further improvement of the present invention, the target oxygen demand includes five-day biochemical oxygen demand, ammonia nitrogen oxidation oxygen demand, and sediment remediation oxygen demand.

[0066] The beneficial effects of this invention are:

[0067] (1) The ecological treatment system and its ecological purification method for rapidly eliminating black and odorous water bodies provided by the present invention treat black and odorous water bodies by fully reoxygenating the water body without the addition of any chemical agents or microbial agents, and will not cause secondary pollution of the water body.

[0068] (2) This invention has no visible bubbles and does not disturb the water body, and can truly achieve the purpose of deodorizing in 1 day and eliminating blackness in 3 days.

[0069] (3) For urban rivers, lakes and canals that are prone to turning black and smelly after rain, the method provided by this invention has a particularly obvious treatment effect, and has a good removal effect on pollutants in black and smelly water bodies, resulting in significant improvement in water quality, which is difficult to achieve with other existing technologies.

[0070] (4) This invention is simple to operate and maintain, and has low cost, approximately 6 cents / m 3 The equipment can be moved or fixed, making it highly mobile and flexible. The layout of the equipment and pipelines will not affect flood control. Attached Figure Description

[0071] Figure 1 This is a schematic diagram of the structure of the conical dissolved gas tank provided by the present invention.

[0072] Figure 2 This is a plan view of the ecological treatment system for rapidly eliminating black and odorous water bodies provided in Embodiment 1 of the present invention.

[0073] Figure 3 This is a time-point graph showing the trend and effect of dissolved oxygen changes in Example 1 of the present invention.

[0074] Figure Labels

[0075] 1-Ultra-nano aerosol equipment; 11-Conical dissolved air tank; 2-Inlet pipe; 3-Outlet pipe; 31-First outlet pipe; 32-Second outlet pipe; 33-Third outlet pipe; 4-Automatic dissolved oxygen monitoring point; 41-First monitoring point; 42-Second monitoring point; 43-Third monitoring point; 5-Inlet pipe; 6-Oxygen bubbles; 7-Rainwater culvert; 71-First rainwater culvert; 72-Second rainwater culvert; 8-Urban main road; 9-Lake. Detailed Implementation

[0076] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0077] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0078] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0079] Please see Figures 1 to 2As shown, the present invention provides an ecological treatment system for rapidly eliminating black and odorous water bodies, including an ultra-nano dissolved oxygenation system and an automatic dissolved oxygen monitoring system; the ultra-nano dissolved oxygenation system includes an ultra-nano dissolved oxygen device 1, an inlet pipe 2 and an outlet pipe 3 connected to the ultra-nano dissolved oxygen device 1, and the automatic dissolved oxygen monitoring system includes several automatic dissolved oxygen monitoring points 4 set along the pipeline; the ultra-nano dissolved oxygen device 1 is connected to an oxygen generation system through an air inlet pipe 5, and the oxygen generation system is either machine-generated oxygen or bottled liquid oxygen in Dewar flasks.

[0080] The diameter of the inlet pipe 2 is 300-400mm. The larger diameter ensures the stability of the inlet flow rate within the treatment area. The outlet pipe 3 is divided into multiple branches, each set at a different location to ensure the uniform distribution of the fully dissolved aerosol water in the ultra-nano aerosol equipment 1. The length of the outlet pipe 3 is 10-500m and the diameter is 20-100mm, which ensures that the oxygen meets the residence time requirements while reducing the disturbance to the water body during drainage.

[0081] Specifically, the ultra-nano aerosol device 1 includes a conical aerosol tank 11, and the formula for calculating the contact radius R of the conical aerosol tank 11 is:

[0082]

[0083] Where R is the contact radius of the conical dissolved gas tank 11, in meters;

[0084] R1—Radius of the top of the conical dissolved gas tank 11, in meters;

[0085] R2—Radius of the bottom of the conical dissolved gas tank 11, in meters;

[0086] h—Height of the conical dissolved gas tank 11, in meters;

[0087] Z-coordinate, refers to the height coordinate of a point inside the conical dissolved gas tank relative to the bottom of the cone;

[0088] The formula for calculating the effective cross-sectional area A of the conical dissolved air tank 11 is:

[0089] A = πR 2 (2)

[0090] Among them, A—the effective cross-sectional area of ​​the conical dissolved air tank 11, m 2 ;

[0091] R—Contact radius of the conical dissolved gas tank 11, in meters;

[0092] π — Pi (the mathematical constant of a circle).

[0093] Water flow rate V in cone-shaped dissolved air tank 11 s The calculation formula is:

[0094]

[0095] Among them, V s —Water flow rate, m / s;

[0096] Q w —Water flow rate, m 3 / s;

[0097] A—Effective cross-sectional area of ​​the conical dissolved gas tank 11, in m² 2 ;

[0098] The formula for calculating the oxygen mass transfer capacity J of the conical dissolved air tank 11 is:

[0099] J = K OL (C s -C0) (4)

[0100] C s =KP i (5)

[0101] Among them, the oxygen mass transfer capacity of the J-shaped cone-shaped dissolved air tank 11 is mol / (m 2 ·s);

[0102] K OL —Mass transfer coefficient, m / s, is related to the radius r of the oxygen bubble, K OL =0.6r (r < 6.67 × 10) -4 m) or K OL =4×10 -4 (r≥6.67×10 -4 m);

[0103] C s —Saturated dissolved oxygen concentration in water body, mol / m³ 3 ;

[0104] C0—Initial dissolved oxygen concentration in the water body, mol / m³ 3 ;

[0105] K — Henry's constant, mol / (Pa·m) 3 );

[0106] P i —Oxygen pressure at a certain depth, Pa;

[0107] According to Henry's Law, the saturated dissolved oxygen content in water is directly proportional to the partial pressure of oxygen. Since the mass transfer coefficient is related to the radius of oxygen bubbles, especially the size of the initial bubble radius, the larger the bubble, the greater the buoyancy in the water, the faster the rising speed, and the shorter its residence time. Pure oxygen generally requires a residence time of more than 60 to 90 seconds to completely dissolve in water. The initial bubble size is generally affected by the influent flow rate and the gas flow rate.

[0108] The formula for calculating the residence time t of oxygen bubbles 6 in the conical dissolved gas tank 11 is as follows:

[0109]

[0110] Where t is the residence time of oxygen bubble 6 in the conical dissolved gas tank 11, in seconds;

[0111] k1—bubble rise coefficient, 0.2~0.5, dimensionless;

[0112] h—Height of the conical dissolved gas tank 11, in meters;

[0113] v b —The rising velocity of oxygen bubble 6, m / s; the radius r of oxygen bubble 6 satisfies r < 7 × 10⁶ -4 m,

[0114] v b =4474r 1.357 (m / s); 7×10 -4 ≤r<5.1×10 -3 m,v b =0.23 (m / s); r≥5.1×10 -3 m,

[0115] v b =4.202r 0.547 (m / s)

[0116] Because pure oxygen requires a residence time of 60-90 seconds or more to dissolve naturally in water, a water column height of approximately 100 meters is needed for complete dissolution under natural conditions. Tests show that the conical dissolved oxygen tank 11 can accelerate dissolution by increasing pressure, but this still cannot meet such a height requirement and is not conducive to engineering implementation. Therefore, a gas-liquid mixing zone is formed at the top of the equipment. The smaller the volume and height of this mixing zone, the better the oxygen dissolution effect and the smaller the effluent bubbles. To further increase oxygen dissolution efficiency, the pipe length at the outlet is extended to allow for continuous dissolution, aiming to achieve a residence time of 60-90 seconds or more. However, pressure loss must be considered; excessively long pipes result in significant pressure loss, leading to higher operating power and increased operating costs. Therefore, by controlling the area of ​​the gas-liquid mixing zone to control bubble size and simultaneously increasing the pipe length at the outlet, the required residence time for pure oxygen is achieved, ensuring complete oxygen dissolution.

[0117] The formula for calculating the height h1 of the gas-liquid mixing zone in the conical dissolved gas tank 11 is:

[0118] h1=h-(V s -v b k)t (7)

[0119] Where h1 is the height of the gas-liquid mixing zone in the conical dissolved gas tank 11, in meters;

[0120] h—Height of the conical dissolved gas tank 11, in meters;

[0121] V s —Water flow rate, m / s;

[0122] v b —Oxygen bubble 6 rising velocity, m / s;

[0123] k—an empirical parameter, 0.3 to 0.4, dimensionless;

[0124] t—the residence time of oxygen bubbles 6 in the conical dissolved gas tank 11, in seconds;

[0125] The height of the gas-liquid mixing zone in the conical dissolved gas tank 11 is more than 95% of the space occupied by bubbles.

[0126] The formula for calculating the residence time t1 of oxygen bubbles 6 in the water outlet pipe 3 is as follows:

[0127]

[0128] Wherein, t1 is the residence time of oxygen bubbles 6 in the water outlet pipe 3, in seconds;

[0129] Q w —Water flow rate, m 3 / s;

[0130] R3—Inner diameter of water outlet pipe 3, in meters;

[0131] L—Length of the water outlet pipe, in meters;

[0132] π — Pi (the mathematical constant of a circle).

[0133] The total residence time of oxygen bubbles 6 in the ultra-nano aerosol device 1 and the outlet pipe 3 is 60–90 s. The pressure in the conical dissolved air tank 11 is 0.4–0.6 MPa to ensure sufficient reoxygenation and the absence of air bubbles.

[0134] The ecological treatment system and ecological purification method for rapidly eliminating black and odorous water bodies, as described above, include the following steps:

[0135] S1. Test the water quality and quantity of the black and odorous water body and calculate the target oxygen demand of the black and odorous water body; the target oxygen demand includes five-day biochemical oxygen demand, ammonia nitrogen oxidation oxygen demand and bottom sediment remediation oxygen demand.

[0136] S2. Install ultra-nano aerosol equipment 1 at the end of the open channel to be treated, install inlet pipe 2 and outlet pipe 3, and install automatic dissolved oxygen monitoring points 4 along the channel.

[0137] S3. Start the ultra-nano aerosol device 1. When the dissolved oxygen in the water begins to show an upward trend, set the running time according to the dissolved oxygen content displayed by the automatic dissolved oxygen monitoring point 4. Start the device when the minimum dissolved oxygen content at the monitoring point is lower than 6 mg / L, and turn off the device when it is higher than 12 mg / L.

[0138] The following describes the ecological treatment system and ecological purification method for rapidly eliminating black and odorous water bodies provided by the present invention, with reference to specific embodiments.

[0139] Example 1

[0140] The area is a plain with a network of waterways and belongs to the northern subtropical monsoon (humid) climate. It is characterized by abundant rainfall, sufficient heat, simultaneous rain and heat, simultaneous sunshine and heat, cold winters and hot summers, and distinct seasons. The average annual temperature is 15.8℃~17.5℃, and the annual precipitation is 1150 mm~1450 mm. Rainfall is concentrated from June to August each year, accounting for about 40% of the annual rainfall.

[0141] like Figure 2 As shown, the open channel to be treated is located in the northeast corner of Lake 9. It is the main drainage channel of the lake's catchment system, with a length of approximately 700 meters and a total area of ​​approximately 12,500 square meters. 2 The water is about 1.5 meters deep on average and is a semi-enclosed channel. Upstream, near the main urban road, there are two stormwater culverts 7, namely the first stormwater culvert 71 and the second stormwater culvert 72. Rainwater from the surrounding area is discharged into this open channel through the stormwater culverts 7. However, due to incomplete separation of rainwater and sewage in the surrounding catchment area, coupled with prominent issues of misconnection and leakage in the drainage network, the problem is complex. Whenever there is moderate to heavy rain, after the weir at the end of the culvert is opened, a large amount of rainwater, sewage, and sludge from the drainage ditches rush into the open channel, making the entire section black and smelly. This is especially true in summer when the temperature is high, accompanied by the continuous upwelling of black and smelly bottom sludge, which seriously affects the lives, leisure, and entertainment experience of urban residents, and also poses a great threat to the water quality of downstream lakes.

[0142] This embodiment provides an ecological treatment system for rapidly eliminating black and odorous water bodies, including an ultra-nano dissolved oxygen reoxygenation system and an automatic dissolved oxygen monitoring system. The ultra-nano dissolved oxygen reoxygenation system includes an ultra-nano dissolved oxygen device 1, an inlet pipe 2 and an outlet pipe 3 connected to the ultra-nano dissolved oxygen device 1. The diameter of the inlet pipe 2 is 300mm. The outlet pipe 3 is divided into three branches: a first outlet pipe 31, a second outlet pipe 32, and a third outlet pipe 33, located at different points, each 150m long and 50mm in diameter, with the ends... Located at a water depth of 1.5 meters, the pressure at the end of the pipeline is not less than 0.3 MPa. Due to the difference in the distance between the points before and after, it can be laid out in a curved manner, but the total length is 150 meters. The fully dissolved aerosol water in the ultra-nano aerosol device 1 flows into the open channel to be treated through the outlet pipe 3. The dissolved oxygen automatic monitoring system includes dissolved oxygen automatic monitoring points 4 set along the route, namely the first monitoring point 41, the second monitoring point 42 and the third monitoring point 43. The ultra-nano aerosol device 1 is connected to the oxygen generation system through the air inlet pipe 5. The oxygen generation system is an oxygen generator.

[0143] like Figure 1 As shown, the ultra-nano aerosol device 1 includes a conical dissolved oxygen tank 11, 2m high, with an upper radius of 0.15m and a lower radius of 1.10m, forming a gas-liquid mixing zone with a height of approximately 0.5m. Calculations show that the oxygen residence time within the conical dissolved oxygen tank 11 is approximately 40s, and the oxygen residence time within the outlet pipe 3 needs to be at least 20s. Therefore, the total length of the outlet pipe 3 is calculated to be at least 100m. To ensure that the pressure at the end of the pipe is not lower than 0.3MPa, the pipe length should not exceed 500m; in this embodiment, 150m is used. The ultra-nano aerosol device 1 can inject 10kg of dissolved oxygen into the water body per hour, with an outlet flow rate of 150m³ / h. 3 / h, equipment dissolved air pressure 0.4~0.6MPa, effluent dissolved oxygen content about 70mg / L.

[0144] The ecological purification method for rapidly eliminating black and odorous water bodies using the above-mentioned ecological treatment system includes the following steps:

[0145] S1. Preliminary investigation: Water quality and quantity of the open channel to be treated were tested, and the target oxygen demand of the black and odorous water body was calculated. The target oxygen demand includes five-day biochemical oxygen demand, ammonia nitrogen oxidation oxygen demand, and bottom sediment remediation oxygen demand. The theoretical oxygen demand was calculated to be 75 mg / L, and the total oxygen demand was 1406 kg. Considering the influencing factors such as air reoxygenation: 0.5-0.7, and taking the value of 0.6, the oxygen demand of the open channel is 843.6 kg.

[0146] S2. Install ultra-nano aerosol equipment 1 at the end of the open channel, install inlet pipe 2 and outlet pipe 3, and install automatic dissolved oxygen monitoring points 4 along the channel.

[0147] S3. Start the ultra-nano dissolved oxygen device 1 and run it for the first 24 hours. When the dissolved oxygen in the water begins to show an upward trend (from 0 to 1 mg / L), set the running time according to the dissolved oxygen content displayed by the automatic dissolved oxygen monitoring point 4. Start the device when the minimum dissolved oxygen content at the monitoring point is lower than 6 mg / L, and turn off the device when it is higher than 12 mg / L.

[0148] The effects before and after treatment in this embodiment are shown in Table 1 and... Figure 3 As shown in Table 1, the open channel water was noticeably black and odorous, requiring a large amount of dissolved oxygen to be added initially. When the dissolved oxygen content began to rise rapidly, the odor was largely eliminated. Continuous and stable reoxygenation further eliminated the black and odorous condition in about 3 days. Maintaining a high dissolved oxygen content resulted in significant water quality degradation in approximately 7 days. Table 1 demonstrates that this invention effectively removes pollutants from black and odorous water bodies, resulting in significant water quality improvement.

[0149] Table 1. Changes in key indicators before and after reoxygenation in Example 1

[0150]

[0151]

[0152] Example 2

[0153] Example 2 provides an ecological purification method for rapidly eliminating black and odorous water bodies. The difference from Example 1 lies only in the use of the ultra-nano aerosol device 1 and the water body to be treated. This water body is an open urban river in a micro-flow state, approximately 2.5 km long and 30-50 m wide, with a significant gradient of about 1‰. Its main function is flood control and drainage, with rainwater as the primary water source and a relatively small flow rate. To create an urban water landscape, concrete drop weirs and rubber dams were constructed at the 1 km mark and at the end of the river, respectively, storing water to a depth of about 1.5 m. However, due to a misconnection problem in the area's drainage system, opening the sluice gates during moderate to heavy rainfall causes a large amount of rainwater and sewage to overflow into the river (from the 1 km mark to the rubber dam), resulting in the river turning black and odorous again, with severe consequences. Therefore, the ultra-nano aerosol device 1 is used for on-site treatment. The ultra-nano aerosol device 1 can inject 5 kg of dissolved oxygen into the water body per hour, with a dissolved oxygen tank pressure of approximately 0.4-0.6 MPa and an outlet flow rate of approximately 100 m³ / h. 3 / h, dissolved air tank height 2.0m, upper bottom radius 0.2m, lower bottom radius 1.8m, outlet pipe inner diameter 25mm, length 480m, other experimental parameters and conditions are basically the same as in Example 1, and will not be repeated here. The effects before and after treatment are shown in Table 2.

[0154] Table 2. Changes in key indicators before and after reoxygenation in Example 2

[0155] project Before treatment Treatment for 3 days 7 days of treatment Target water quality pH 7.3 7.2 7.5 6-9 Ammonia nitrogen (mg / L) 9.35 7.21 4.37 ＜8 Sulfides (mg / L) 12.37 0.16 0.11 / Redox potential (mV) -98.3 165.3 224.6 ＞50 Transparency (cm) ＜10 43 55 ＞25 Dissolved oxygen (mg / L) 0.27 11.31 12.56 ＞2

[0156] As can be seen from Table 2, the 5kg / h ultra-nano dissolved oxygenation system used in this embodiment basically achieves the effect of Embodiment 1. That is, after the system is put into operation, it can quickly deodorize the water, degrade sulfides very rapidly, and because the system does not have visible bubbles, it will not carry the existing odor into the air and cause secondary pollution. The oxidation-reduction potential and transparency are significantly improved, basically achieving the goal of quickly eliminating black spots and deodorizing within 3 days after rain, and the water continues to improve as the equipment continues to operate.

[0157] Example 3

[0158] Example 3 provides an ecological purification method for rapidly eliminating black and odorous water bodies. Compared with Example 1, the only difference is that the water body to be treated is different. It is a landscape river in a plain water network, a semi-open river with a length of about 1 km, a width of 15-30 m, and an average water depth of about 2 m. It is mainly replenished by natural rainfall, with complete surrounding green facilities and the regional rainwater and sewage separation transformation is basically completed. The water quality of the river is usually well maintained. However, due to a period of continuous heavy snow and a sudden drop in temperature, the sewage pipe crossing the river broke, and a large amount of sewage entered the river for a week, causing this section to become abnormally black and odorous, which was repeatedly complained about by the surrounding residents. In order to quickly solve the black and odorous problem of this section of the river, the ultra-nano aerosol device 1 from Example 1 was introduced to this site for pilot testing. Other experimental parameters and conditions are basically the same as those in Example 1, and will not be repeated here. The effects before and after treatment are shown in Table 3.

[0159] Table 3. Changes in key indicators before and after reoxygenation in Example 3

[0160] project Before treatment Treatment for 3 days 7 days of treatment 30 days of treatment Target water quality pH 6.8 7.4 7.3 7.7 6-9 Ammonia nitrogen (mg / L) 15.71 12.46 8.32 1.67 ＜8 Sulfides (mg / L) 8.34 0.16 0.11 0.07 / Redox potential (mV) -128.2 178.6 215.3 236.8 ＞50 Transparency (cm) ＜10 43 65 74 ＞25 Dissolved oxygen (mg / L) 0.16 12.78 12.36 12.57 ＞2

[0161] As can be seen from Table 3, the water body in this embodiment was greatly affected by sewage, with a low oxidation-reduction potential and insufficient transparency. After the ultra-nano aerosol device 1 was started and operated, the dissolved oxygen and oxidation-reduction potential increased rapidly, the water transparency improved significantly, the sulfide content dropped rapidly from 8.34 mg / L to 0.16 mg / L, and the odor disappeared. The goal of eliminating blackening and deodorization was basically achieved in 3 days. After 30 days of continuous reoxygenation, the water body in this embodiment gradually returned to the state before the sewage entered, and the water quality was good.

[0162] Example 4

[0163] Example 4 provides an ecological purification method for rapidly eliminating black and odorous water bodies. Compared with Example 1, the only difference is that the length of the outlet pipe 3 is 200m, and the calculated oxygen residence time in the outlet pipe 3 is 38s. Other experimental parameters and conditions are basically the same as in Example 1, and will not be repeated here. The effects before and after treatment are shown in Table 4.

[0164] Table 4. Changes in key indicators before and after reoxygenation in Example 4

[0165] project Before treatment Treatment for 3 days 7 days of treatment Target water quality pH 6.3 7.0 7.4 6-9 Ammonia nitrogen (mg / L) 14.30 8.31 4.29 ＜8 Sulfides (mg / L) 12.62 0.27 0.14 / Redox potential (mV) -189.4 98.7 125.9 ＞50 Transparency (cm) ＜10 55 68 ＞25 Dissolved oxygen (mg / L) 0.36 13.71 12.87 ＞2

[0166] As can be seen from Table 4, the equipment capacity of this embodiment is 10 kg / h, and the outflow rate is 150 m³ / h. 3 / h, but by extending the pipeline length, it can cover a longer and farther distance, and the reoxygenation effect can still meet the equipment performance requirements. Through the operation of this system, the black and odorous phenomenon disappears quickly within 3 days, meeting the relevant requirements.

[0167] Comparative Example 1

[0168] Comparative Example 1 provides an ecological purification method for rapidly eliminating black and odorous water bodies. Compared with Example 1, the only difference is that the dissolved gas pressure of the ultra-nano aerosol device is 0.25-0.35 MPa, and the height of the gas-liquid mixing zone is higher, about 0.6 m. Other experimental parameters and conditions are basically the same as those in Example 1, and will not be repeated here. The effects before and after treatment are shown in Table 5.

[0169] Table 5. Changes in key indicators before and after reoxygenation in Comparative Example 1

[0170] project Before treatment Treatment for 3 days 7 days of treatment Target water quality pH 6.3 7.3 7.6 6-9 Ammonia nitrogen (mg / L) 14.30 12.17 8.58 ＜8 Sulfides (mg / L) 12.62 3.31 2.17 / Redox potential (mV) -189.4 -23.9 52.7 ＞50 Transparency (cm) ＜10 18 31 ＞25 Dissolved oxygen (mg / L) 0.36 1.37 3.21 ＞2

[0171] As can be seen from Table 5, adjusting the pressure of the dissolved air tank in the ultra-nano dissolved air equipment significantly increased the height of the gas-liquid mixing zone. However, the oxygen residence time in the dissolved air tank was insufficient. With the original water outlet pipe unchanged, there were obvious bubbles in the water outlet, indicating poor oxygenation. The water quality improvement results also clearly show that the dissolved oxygen increase was slow. The main reason is that most of the oxygen overflowed into the air due to insufficient residence time, resulting in a significant decrease in oxygen residence time and utilization rate. At the same time, the visible bubbles carried the odor from the water into the air, causing secondary pollution. It took 7 days to achieve the goal of eliminating black spots and odors, which is significantly less efficient than Example 1.

[0172] Comparative Example 2

[0173] Comparative Example 2 provides an ecological purification method for rapidly eliminating black and odorous water bodies. Compared with Example 1, the only difference is that the dissolved gas pressure of the ultra-nano aerosol device is 0.70-0.85 MPa, and the height of the gas-liquid mixing zone is about 0.45 m. Other experimental parameters and conditions are basically the same as those in Example 1, and will not be repeated here. The effects before and after treatment are shown in Table 6.

[0174] Table 6. Changes in key indicators before and after reoxygenation in Comparative Example 2

[0175] project Before treatment Treatment for 3 days 7 days of treatment Target water quality pH 6.3 7.7 7.4 6-9 Ammonia nitrogen (mg / L) 14.30 6.21 5.73 ＜8 Sulfides (mg / L) 12.62 0.17 0.14 / Redox potential (mV) -189.4 176.8 198.6 ＞50 Transparency (cm) ＜10 52 56 ＞25 Dissolved oxygen (mg / L) 0.36 12.15 12.43 ＞2

[0176] As can be seen from Table 6, by adjusting the pressure of the dissolved air tank, the height of the gas-liquid mixing zone can be reduced, thereby increasing the oxygen solubility of the equipment. With the water flow rate and pipe inner diameter remaining unchanged, the dissolved oxygen concentration in the effluent is higher, and the bubbles are smaller and invisible to the naked eye. For areas with severe oxygen deficiency, oxygen can be replenished quickly to meet the dissolved oxygen requirements of the water body. The results show that the goal of quickly eliminating black and odorous water can still be achieved. However, increasing the pressure of the dissolved air tank increases energy consumption compared to Example 1. At the same time, the increased pressure of the effluent pipe leads to higher material requirements. Therefore, the technical effect of Comparative Example 2 is not much different from that of Example 1, but the operating cost is significantly higher.

[0177] Comparative Example 3

[0178] Comparative Example 3 provides an ecological purification method for rapidly eliminating black and odorous water bodies. The only difference from Example 1 is that it uses existing micro-nano reoxygenation technology to treat the black and odorous water bodies in Example 1, as detailed below:

[0179] S1. Calculate the theoretical oxygen demand of the water body. As in Example 1, the oxygen demand of this open channel is 843.6 kg.

[0180] S2. Install micro-nano reoxygenation equipment. In this embodiment, six micro-nano reoxygenation devices (each 2.2kW) are used, arranged in a perforated pipe layout.

[0181] S3. Start the micro-nano reoxygenation equipment and run it for 24 hours. The effects before and after treatment are shown in Table 7.

[0182] Table 7. Changes in key indicators before and after reoxygenation in Comparative Example 3

[0183] project Before treatment Treatment for 3 days 7 days of treatment Target water quality pH 6.3 6.7 7.2 6-9 Ammonia nitrogen (mg / L) 14.31 11.78 8.17 ＜8 Sulfides (mg / L) 12.62 5.36 2.14 / Redox potential (mV) -189.4 10.8 45.7 ＞50 Transparency (cm) ＜10 18 30 ＞25 Dissolved oxygen (mg / L) 0.36 1.21 2.37 ＞2

[0184] As can be seen from Table 7, the oxygen replenishment efficiency of ordinary micro-nano reoxygenation technology is not high, making it difficult to achieve the goal of quickly eliminating black spots and odors within 3 days after rain. At the same time, due to the micro-nano bubbles, the existing odor in the water is carried into the air, causing secondary pollution. Although it can basically achieve the goal of eliminating black spots and odors within 7 days, the operating cost is high, and the perforated pipe layout is prone to blockage. It is also easily damaged by the impact of mixed sewage during rainy days.

[0185] In summary, the ecological treatment system and its ecological purification method for rapidly eliminating black and odorous water provided by this invention treat black and odorous water by fully reoxygenating the water body. It does not involve the addition of any chemical agents or microbial agents, does not cause secondary pollution of the water body, produces no visible bubbles, does not disturb the water body, and can achieve the purpose of rapidly eliminating blackness and odor.

[0186] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. An ecological treatment system for rapidly eliminating black and odorous water bodies, characterized in that, It includes an ultra-nano dissolved oxygen reoxygenation system and an automatic dissolved oxygen monitoring system; the ultra-nano dissolved oxygen reoxygenation system includes an ultra-nano dissolved oxygen device, an inlet pipe and an outlet pipe connected to the ultra-nano dissolved oxygen device; the automatic dissolved oxygen monitoring system includes several automatic dissolved oxygen monitoring points set along the process; the ultra-nano dissolved oxygen device is connected to the oxygen generation system through an air inlet pipe; The ultra-nano aerosol device includes a conical aerosol tank, and the formula for calculating the contact radius R of the conical aerosol tank is: （1） Where R is the contact radius of the conical dissolved gas tank, in meters; R1—Radius of the top of the conical dissolved gas tank, in meters; R2—Radius of the bottom of the conical dissolved gas tank, in meters; h—Height of the conical dissolved gas tank, in meters; Z-coordinate, referring to the height coordinate of a point inside the conical dissolved gas tank relative to the bottom of the cone; The formula for calculating the effective cross-sectional area A of the conical dissolved air tank is as follows: （2） Wherein, A—the effective cross-sectional area of ​​the cone-shaped dissolved air tank, m 2 ; R—Contact radius of the conical dissolved gas tank, in meters; π — Pi (the mathematical constant of a circle). The water flow rate V inside the conical dissolved air tank s The calculation formula is: （3） Among them, V s —Water flow rate, m / s; Q w —Water flow rate, m 3 / s; A—Effective cross-sectional area of ​​the conical dissolved gas tank, in m² 2 ; The formula for calculating the oxygen mass transfer capacity J of the conical dissolved air tank is: （4） （5） Among them, J—the oxygen mass transfer capacity of the conical dissolved air tank, mol / (m 2 ·s); K OL —Mass transfer coefficient, m / s, related to the oxygen bubble radius r, K OL =0.6r (r < 6.67 × 10) -4 m) or K OL =4×10 -4 (r≥6.67×10) -4 m); C s —Saturated dissolved oxygen concentration in water body, mol / m³ 3 ; C0—Initial dissolved oxygen concentration in the water body, mol / m³ 3 ; K — Henry's constant, mol / (Pa·m) 3 ); P i —Oxygen pressure at a certain depth, Pa; The formula for calculating the residence time t of the oxygen bubbles in the conical dissolved gas tank is: （6） Where t is the residence time of oxygen bubbles in the conical dissolved gas tank, in seconds; k1—bubble rise coefficient, 0.2~0.5, dimensionless; h—Height of the conical dissolved gas tank, in meters; v b —The rising velocity of the oxygen bubble, m / s; the radius r of the oxygen bubble satisfies r < 7 × 10⁻⁶. -4 m, 7×10 -4 ≤r<5.1×10 -3 m, r≥5.1×10 -3 m, ; The formula for calculating the height h1 of the gas-liquid mixing zone in the conical dissolved gas tank is as follows: （7） Where h1 is the height of the gas-liquid mixing zone in the conical dissolved gas tank, in meters; h—Height of the conical dissolved gas tank, in meters; V s —Water flow rate, m / s; v b —Oxygen bubble rising velocity, m / s; k—an empirical parameter, 0.3~0.4, dimensionless; t — Residence time of oxygen bubbles in the conical dissolved gas container, s; The formula for calculating the residence time t1 of the oxygen bubbles in the water outlet pipe is: （8） Where t1 is the residence time of oxygen bubbles in the water outlet pipe, in seconds; Q w —Water flow rate, m 3 / s; R3—Inner diameter of the outlet pipe, in meters; L—Length of the outlet pipe, in meters; π — Pi (the mathematical constant of a circle). The total residence time of the oxygen bubbles in the ultra-nano aerosol device and the water outlet pipe is 60-90 seconds. The pressure in the conical dissolved gas tank is 0.4~0.6MPa.

2. The ecological treatment system for rapidly eliminating black and odorous water bodies according to claim 1, characterized in that, The water outlet pipes are divided into multiple branches, each located at a different point.

3. The ecological treatment system for rapidly eliminating black and odorous water bodies according to claim 2, characterized in that, The length of the water outlet pipe is 10~500m, and the diameter is 20~100mm.

4. The ecological treatment system for rapidly eliminating black and odorous water bodies according to claim 1, characterized in that, The diameter of the water inlet pipe is 300~400mm.

5. The ecological treatment system for rapidly eliminating black and odorous water bodies according to claim 1, characterized in that, The oxygen generation system is either machine-generated oxygen or liquid oxygen in a Dewar flask.

6. An ecological purification method for rapidly eliminating black and odorous water bodies, employing the ecological treatment system for rapidly eliminating black and odorous water bodies as described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Test the water quality and quantity of black and odorous water bodies and calculate the target oxygen demand for black and odorous water bodies; S2. Install ultra-nano aerosol equipment at the end of the open channel to be treated, and install inlet and outlet pipes. At the same time, install automatic dissolved oxygen monitoring points along the channel. S3. Start the ultra-nano dissolved oxygen device. When the dissolved oxygen in the water begins to rise, set the running time according to the dissolved oxygen content displayed by the automatic dissolved oxygen monitoring point. Start the device when the minimum dissolved oxygen content at the monitoring point is below 6 mg / L, and turn off the device when it is above 12 mg / L.

7. The ecological purification method for rapidly eliminating black and odorous water bodies according to claim 6, characterized in that, The target oxygen demand includes five-day biochemical oxygen demand, ammonia nitrogen oxidation oxygen demand, and sediment remediation oxygen demand.

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