An oxidation pond system for treating livestock wastewater

Abstract

This invention relates to an oxidation pond system for treating livestock breeding wastewater, comprising solar panels, a buoyancy unit, a stirring unit, and an electrocoagulation unit. Several solar panels are mounted on the buoyancy unit and float on the surface of the wastewater in the oxidation pond. Several motors of the stirring unit and the power supply of the electrocoagulation unit are located on the buoyancy unit and connected to the solar panels, utilizing solar energy to power the oxidation pond system. Several stirring sections of the stirring unit and several cathode and anode plates of the electrocoagulation unit extend downwards into the oxidation pond and are submerged in the wastewater, performing electrocoagulation treatment on the wastewater while in a stirring state. Several aeration pipes are provided at the bottom of the oxidation pond, with a stirring section and an aeration pipe positioned between a pair of cathode and anode plates, enabling stirring and aeration of a specific electrocoagulation area, thereby improving treatment efficiency.

Description

Technical Field

[0001] This invention belongs to the field of wastewater oxidation treatment technology, specifically relating to an oxidation pond system for treating livestock breeding wastewater. Background Technology

[0002] With the rapid transformation of livestock production methods, scientific feeding and technological levels have continued to improve, especially in dairy farming, which has seen rapid development and significant increases in scale, intensification, and industrialization. Livestock farming also generates large amounts of wastewater high in organic matter, nitrogen, and phosphorus. The main treatment methods include returning the wastewater to the fields, industrial wastewater treatment, and natural treatment. Currently, large-scale dairy farms in northern my country primarily utilize oxidation ponds, a natural treatment method, to treat livestock wastewater, which has advantages such as economy, low investment, and ease of maintenance. However, oxidation ponds also have disadvantages such as low treatment efficiency (COD removal rate of only 50%-60%, nitrogen and phosphorus removal rate of less than 40%) and long retention times. Furthermore, many large-scale farms are located in suburban or rural areas, allowing for relatively large oxidation pond areas, but the power grid may be unstable or electricity prices may be high. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides an oxidation pond system for treating livestock breeding wastewater, comprising solar panels, a buoyancy unit, a stirring unit, and an electrocoagulation unit. Several solar panels are mounted on the buoyancy unit and can float on the surface of the wastewater in the oxidation pond. Several motors of the stirring unit and the power supply of the electrocoagulation unit are mounted on the buoyancy unit and connected to the solar panels, thereby utilizing solar energy to power the oxidation pond system.

[0004] Several stirring sections of the stirring unit and several cathode and anode plates of the electrocoagulation unit extend downward into the oxidation pond and are submerged in the wastewater. Under stirring conditions, the wastewater is treated by electrocoagulation. Several aeration pipes are provided at the bottom of the oxidation pond. A stirring section and an aeration pipe are set between a pair of cathode and anode plates, which can be used to stir and aerate a single electrocoagulation area, thereby improving treatment efficiency.

[0005] This invention improves oxidation ponds used for treating livestock wastewater. A buoyancy unit is equipped with the aforementioned units and can guide them to float within the oxidation pond. The modification method is simple, facilitating the upgrading of existing oxidation ponds and promoting future adoption. Electrocoagulation technology, as a highly efficient and compact physicochemical treatment technology, has advantages in treating recalcitrant wastewater; however, its relatively high energy consumption limits its widespread application. In this invention, a solar panel is mounted above the buoyancy unit, and a stirring unit and an electrocoagulation unit are located below it. The motors and power supplies for both units are connected to the solar panel, utilizing solar energy to drive the stirring section and power the electrode plates, achieving low-carbon wastewater treatment. The area between a pair of anode and cathode plates is the electrocoagulation zone, where a stirring section and an aeration pipe are correspondingly installed to increase water turbulence and further improve treatment efficiency.

[0006] Optionally, the buoyancy unit is a buoyancy plate that can float on the surface of wastewater; several solar panels are evenly arranged on the buoyancy plate, all of which can receive sunlight; the top of the stirring part passes through the buoyancy plate and is connected to the motor shaft on the buoyancy plate, with the stirring part and the motor corresponding one-to-one.

[0007] The tops of both the cathode and anode plates are detachably connected to the lower surface of the buoyancy plate. The wires of the cathode plate pass through the buoyancy plate and are then connected to the positive terminal of the power supply; the wires of the anode plate pass through the buoyancy plate and are then connected to the negative terminal of the power supply to energize the electrode plates.

[0008] Optionally, several electrode plates below the buoyancy plate are parallel to each other and evenly distributed along the length of the buoyancy plate, with cathode plates and anode plates alternately arranged; the anode plate is an iron plate or an aluminum plate, and the cathode plate is a stainless steel plate or a graphite plate.

[0009] Alternatively, the spacing between two adjacent electrode plates is equal, with a spacing of 20-30cm; a stirring section is set in the middle between the cathode and anode plates, and the aeration pipe is also located in the middle between the cathode and anode plates, so that stirring and aeration can be evenly applied within an electrocoagulation area.

[0010] Alternatively, several aeration pipes are parallel to each other and evenly distributed along the length of the buoyancy plate at the bottom of the oxidation pond; the two ends of the aeration pipes are close to the two opposite sides of the oxidation pond, and several aeration holes are evenly distributed on the upper surface of the aeration pipes; the main air pipe connects all the aeration pipes in parallel, and an air pump outside the oxidation pond supplies air to the aeration pipes.

[0011] In practical applications, considering the weight of the solar panels, stirring unit, and electrocoagulation unit, as well as the buoyancy of the buoyancy plate, the number of solar panels, stirring units, and motor plates loaded on the buoyancy plate is limited. However, the area of ​​the oxidation pond may be large, requiring the buoyancy plate to move throughout the pond to more effectively treat the wastewater. Adding power facilities around the buoyancy plate not only increases energy consumption but also increases the load on the buoyancy plate. This invention addresses this problem by proposing the following solution.

[0012] Optionally, the stirring part is rod-shaped and inclined, which can push the buoyancy plate to move; adjacent stirring parts are inclined in opposite directions, which can push the buoyancy plate to move in opposite directions; the motor on the buoyancy plate is also tilted and fixed.

[0013] Conventional agitators have a vertically positioned stirring rod with several horizontally or inclined impellers. These agitators can stir water to rotate horizontally, forming circular or conical vortices with a vertical central axis. Therefore, traditional agitators cannot propel a buoyancy plate laterally. This invention improves upon the agitator by tilting it entirely, resulting in a dual disturbance effect—both vertical and horizontal—generating lateral thrust while stirring. If a conventional agitator with impellers is simply tilted, the gravity of the water causes uneven stirring, leading to instability during rotation and resulting in vertical or oblique oscillations. Further improvements are needed.

[0014] Further optionally, the stirring part includes a central rod, a plurality of first bulging parts and a plurality of second bulging parts, the central rod is inclined, the first bulging parts are all located in the upper middle part of the central rod, the second bulging parts are all located in the lower middle part of the central rod, the first bulging parts are circular, the second bulging parts are elliptical, and the major axis of the second bulging parts is parallel to the central rod.

[0015] A ring of stirring paddles is provided between two adjacent first bulges, and a ring of stirring paddles is also provided between two adjacent second bulges to expand the stirring range.

[0016] Further optionally, a plurality of support rods are provided around the central rod, and the plurality of support rods are evenly arranged along the circumference of the central rod; the plurality of support rods protrude outward toward the outside of the stirring part at the same position corresponding to the central rod, forming a first bulge or a second bulge; except for the bulge, the other parts of the support rods are parallel to the central rod and form a bundle with the central rod.

[0017] Further optionally, the side wall of the central rod is provided with a stirring paddle, and several stirring paddles in the same circle are evenly distributed along the circumference of the central rod and have the same height;

[0018] The head of the agitator is connected to the central rod, and the tail extends outward toward the agitator. The agitator extends out from the gap between the support rods without affecting the support rods.

[0019] Further optionally, the radius of the first bulge is the maximum vertical distance between the middle of the corresponding support rod and the central rod, and the minor axis radius of the second bulge is the maximum vertical distance between the middle of the corresponding support rod and the central rod; the lengths of both bulges are along the length direction of the central rod.

[0020] The ratio of the radius of the first bulge to the minor axis radius of the second bulge is 1:(1.1-2.2); the ratio of the length of the first bulge to the length of the second bulge is 1:(1.6-2.7).

[0021] Further optional, along the length of the mixing section, a ring of long mixing blades and a ring of short mixing blades are alternately arranged, with long mixing blades provided at both the top and bottom of the mixing section;

[0022] The ratio of the length of the short agitator to the length of the long agitator is 1:(1.5-2.1); the ratio of the minor axis radius of the second bulge to the length of the short agitator is 1:(1.1-1.3).

[0023] In this invention, when treating livestock wastewater, an electrocoagulation zone is formed between a pair of anode and cathode plates, and several electrocoagulation zones are located below the buoyancy plate. Within each electrocoagulation zone, corresponding stirring sections agitate the wastewater, and corresponding aeration pipes aerate it, concentrating the agitation of the wastewater within the electrocoagulation zone. This synergy with the electrocoagulation process improves treatment efficiency. The sludge produced by electrocoagulation settles at the bottom of the oxidation pond and is periodically dredged. Adjacent stirring sections are tilted in opposite directions, pushing the buoyancy plate in both directions. This allows the buoyancy plate to carry the electrode plates through most of the oxidation pond. For example, all stirring sections with their bottoms tilted to the left rotate simultaneously and at the same speed, pushing the buoyancy plate to the right until it reaches the far right side of the oxidation pond. Then, the previously rotating stirring sections pause, and all stirring sections with their bottoms tilted to the right rotate simultaneously and at the same speed, pushing the buoyancy plate to the left until it reaches the far left side of the oxidation pond. This control of the buoyancy plate's back-and-forth movement within the oxidation pond ensures thorough wastewater treatment. Moreover, all electrode plates are constantly energized, and the water flow in the electrocoagulation zone with stirring is violently disturbed, resulting in a very good treatment effect; while in the adjacent electrocoagulation zone without stirring, the water flow is also in a relatively moving state as the buoyancy plate moves, and the corresponding aeration pipe can appropriately increase the aeration volume to increase the disturbance, which also has a water treatment effect.

[0024] This invention improves the rotational stability of the stirring section by arranging first and second bulges on the stirring section and using stirring paddles of varying lengths. Specifically, for the upper part of the stirring section, where the water level is shallow and the water pressure is low, a first bulge with a small radius is used. Between two adjacent first bulges, there is a ring of long or short stirring paddles. The first bulges first stir the water, forming small, inclined vortices from top to bottom. The stirring paddles between each pair of small vortices rotate, forming slightly larger vortices at the short stirring paddles and even larger vortices at the long stirring paddles. The alternation of large and small vortices avoids the simultaneous formation of large vortices and the overcoming of large resistance at the same time. The overall water resistance experienced by the upper part of the stirring section is controllable, preventing the stirring section from outputting large power due to overcoming large water resistance, which would lead to instability.

[0025] For the lower part of the stirring section, where the water level is deeper and the water pressure is greater, a second expansion section with a larger radius is used, along with long and short stirring paddles, to perform a similar function as described above, rotating stably in the lower part of the oxidation pond and stirring the water. Attached Figure Description

[0026] Figure 1 A schematic diagram of an oxidation pond system for treating livestock breeding wastewater;

[0027] Figure 2 This is a schematic diagram of the stirring section;

[0028] Figure 3 This is a top view of the cross-section of the stirring section;

[0029] Figure 4 This is a schematic diagram of the side of the support rod.

[0030] Among them, 1-battery panel, 2-buoyancy plate, 3-motor, 4-power supply, 5-stirring part, 6-cathode plate, 7-anode plate, 8-aeration pipe, 9-support column, 10-center rod, 11-first expansion part, 12-second expansion part, 13-long stirring paddle, 14-short stirring paddle, 15-support rod, 16-plastic plate. Detailed Implementation

[0031] The following examples and comparative examples were implemented at a large-scale dairy farm in Hebei Province. This dairy farm is located in an area with long hours of sunshine, averaging approximately 8.5 hours per day, making it suitable for solar power generation. It has nearly 6,500 dairy cows and produces approximately 117 tons of dairy farm wastewater daily. The wastewater is treated using a three-stage oxidation pond system, with each of the three oxidation ponds having a volume of 25,000 m³. 3 (Level 1 pond), 20,000 m 3 (Secondary pond) and 60,000 m 3 (Third-level pond).

[0032] Taking the secondary pond as an example, the secondary pond is a cuboid with a length of 59.5m, a width of 58m, and a depth of 5.8m.

[0033] Example 1

[0034] This embodiment provides an oxidation pond system for treating livestock breeding wastewater, such as... Figures 1-4 As shown, the system includes a solar panel, a buoyancy unit, a stirring unit, and an electrocoagulation unit. Two solar panels 1 (silicon crystal photovoltaic panels) are mounted on the buoyancy unit and can float on the surface of the wastewater in the oxidation pond. The four motors 3 of the stirring unit and the power supply 4 of the electrocoagulation unit are mounted on the buoyancy unit and connected to the solar panels 1, using solar energy to power the oxidation pond system.

[0035] The four stirring sections 5 of the stirring unit and the eight cathode plates 6 and anode plates 7 of the electrocoagulation unit extend downward into the oxidation pond and are submerged in the wastewater. Under stirring conditions, the wastewater is treated by electrocoagulation. The bottom of the oxidation pond is equipped with four aeration pipes 8. A stirring section 5 and an aeration pipe 8 are set between a pair of cathode and anode plates 7, which can be used to stir and aerate a single electrocoagulation area, thereby improving treatment efficiency.

[0036] The buoyancy unit is a buoyancy plate 2, which can float on the surface of wastewater; two solar panels are evenly arranged on the buoyancy plate 2, and both can receive sunlight; the top of the stirring part 5 passes through the buoyancy plate 2 and is connected to the motor shaft on the buoyancy plate 2, and the stirring part 5 corresponds to the motor one by one.

[0037] The tops of both the cathode plate 6 and the anode plate 7 are detachably connected to the lower surface of the buoyancy plate 2. The wires of the cathode plate 6 pass through the buoyancy plate 2 and are then connected to the positive terminal of the power supply; the wires of the anode plate 7 pass through the buoyancy plate 2 and are then connected to the negative terminal of the power supply to energize the electrode plates.

[0038] The solar panel is hinged to a support column 9 in the middle, and the bottom of the support column 9 is connected to the upper surface of the buoyancy plate 2. This allows the tilt angle of the solar panel to be adjusted according to the real-time position of the sun, ensuring that the upper surface of the solar panel always faces the sun during the day. The location where the electrical wire passes through the buoyancy plate 2 is sealed, and the location where the stirring part 5 passes through the buoyancy plate 2 is shaft-sealed to prevent wastewater from entering the upper surface of the buoyancy plate 2 through the holes.

[0039] The electrode plates below the buoyancy plate 2 are parallel to each other and evenly distributed along the length of the buoyancy plate 2. The cathode plate 6 and the anode plate 7 are alternately arranged. The length of the electrode plate is not greater than the width of the buoyancy plate 2. The height of the electrode plate is adjusted according to the depth of the wastewater in the oxidation pond. The anode plate 7 is an iron plate and the cathode plate 6 is a stainless steel plate.

[0040] The spacing between adjacent electrode plates is equal, with a spacing of 30 cm. A stirring section 5 is located in the middle between the cathode and anode plates, and an aeration pipe 8 is also positioned in the middle between the cathode and anode plates, ensuring that stirring and aeration can act evenly within an electrocoagulation area. The maximum output voltage of the solar panel supplying the power source is 60 V, while the maximum output voltage of the solar panel supplying the motor is 20 V.

[0041] Four aeration pipes 8 are parallel to each other and are evenly distributed at the bottom of the oxidation pond along the length of the buoyancy plate 2. The two ends of the aeration pipes 8 are close to the two opposite sides of the oxidation pond, and several aeration holes are evenly distributed on the upper surface of the aeration pipes 8. The main air pipe connects each aeration pipe 8 in parallel, and the air pump outside the oxidation pond supplies air to the aeration pipes 8.

[0042] The stirring part 5 is rod-shaped and inclined, which can push the buoyancy plate 2 to move; the adjacent stirring parts 5 are inclined in opposite directions, which can push the buoyancy plate 2 to move in opposite directions.

[0043] If the bottom of the stirring section 5 tilts to the right, it can push the buoyancy plate 2 to move to the left; if the bottom of the stirring section 5 tilts to the left, it can push the buoyancy plate 2 to move to the right.

[0044] The stirring part 5 includes a central rod 10, two first bulges 11 and two second bulges 12. The central rod 10 is inclined and forms a 30° angle with the vertical direction. The first bulges 11 are all located in the upper middle part of the central rod 10, and the second bulges 12 are all located in the lower middle part of the central rod 10. The first bulges 11 are circular and the second bulges 12 are elliptical. The major axis of the second bulges 12 is parallel to the central rod 10, so that the inclined stirring part 5 can remain as stable as possible when rotating, and avoid violently swinging around when the stirring part 5 rotates.

[0045] A ring of stirring paddles is provided between two adjacent first bulges 11, and a ring of stirring paddles is also provided between two adjacent second bulges 12 to expand the stirring range.

[0046] The central rod 10 is surrounded by four support rods 15, which are evenly arranged around the circumference of the central rod 10. The four support rods 15 protrude outward from the stirring part 5 at the same position corresponding to the central rod 10, forming a first bulge 11 or a second bulge 12. Except for the bulge, the other parts of the support rods 15 are parallel to the central rod 10 and form a bundle with the central rod 10.

[0047] The side wall of the central rod 10 is provided with a stirring paddle, and several stirring paddles in the same circle are evenly distributed along the circumference of the central rod 10 and have the same height.

[0048] The head of the stirring paddle is connected to the central rod 10, and the tail extends outward toward the stirring part 5. The stirring paddle extends out from the gap between the support rods 15 without affecting the support rods 15.

[0049] Two first bulges 11 occupy the upper half of the stirring part 5, and two second bulges 12 occupy the lower half of the stirring part 5; the distance between two adjacent first bulges 11 is equal, the distance between two adjacent second bulges 12 is equal, and the distance between two adjacent first bulges 11 is equal to the distance between two adjacent second bulges 12.

[0050] A ring of stirring paddles is provided at the middle position between two adjacent first bulges 11, and a ring of stirring paddles is provided at the middle position between two adjacent second bulges 12.

[0051] Each of the arc-shaped support rods 15 of the bulge is equipped with a plastic plate 16 inside. The outer side of the plastic plate 16 is detachably connected to the support rod 15. The inner side of the plastic plate 16 is parallel to the central rod 10 and extends radially towards the central rod 10 along the bulge, so that the bulge can better agitate the water.

[0052] The radius of the first bulge 11 is the maximum vertical distance between the middle of the corresponding support rod 15 and the central rod 10, and the radius of the minor axis of the second bulge 12 is the maximum vertical distance between the middle of the corresponding support rod 15 and the central rod 10; the length of both bulges is along the length direction of the central rod 10.

[0053] The ratio of the radius of the first bulge 11 to the minor axis radius of the second bulge 12 is 1:1.1; the ratio of the length of the first bulge 11 to the length of the second bulge 12 is 1:1.6.

[0054] Along the length of the stirring section 5, a ring of long stirring paddles 13 and a ring of short stirring paddles 14 are alternately arranged, and long stirring paddles 13 are provided at the top and bottom of the stirring section 5.

[0055] The ratio of the length of the short impeller 14 to the length of the long impeller 13 is 1:1.5; the ratio of the minor axis radius of the second bulge 12 to the length of the short impeller 14 is 1:1.1.

[0056] Comparative Example 1

[0057] This comparative example provides an oxidation pond system for treating livestock breeding wastewater, which is the same as Example 1, except that it does not include an aeration pipe and a stirring unit.

[0058] Comparative Example 2

[0059] This comparative example provides an oxidation pond system for treating livestock breeding wastewater, which is the same as Example 1, except that it does not include a stirring unit.

[0060] After the oxidation pond was operating stably, it treated wastewater during the day and stopped treating it at night. Compared with Comparative Example 1, the removal rates of chemical oxygen demand (COD), total phosphorus, total nitrogen, and ammonia nitrogen in Comparative Example 2 increased by 4.1%, 5.4%, 2.1%, and 3.3%, respectively. Compared with Comparative Example 1, the removal rates of COD, total phosphorus, total nitrogen, and ammonia nitrogen in Example 1 increased by 14.8%, 17.5%, 7.3%, and 9.6%, respectively.

[0061] Example 2

[0062] This embodiment provides an oxidation pond system for treating livestock breeding wastewater, which is the same as that in Embodiment 1. The difference is that a conventional vertically arranged stirring part is used, and a stirring paddle is connected to the outside of the central rod of the stirring part. The length of the stirring paddle is the same as that of the long stirring paddle in Embodiment 1. The number of stirring paddles in this embodiment is the same as that in Embodiment 1.

[0063] Since the buoyancy plate cannot move autonomously within the oxidation pond, it can only be moved with the help of external forces. In this case, ropes are used to pull the buoyancy plate from both sides, which requires additional energy.

[0064] Example 3

[0065] This embodiment provides an oxidation pond system for treating livestock breeding wastewater, which is the same as that in Embodiment 1, except that the stirring part only includes a first expansion part and a long stirring paddle, and the first expansion part and a ring of long stirring paddles are alternately arranged.

[0066] Example 4

[0067] This embodiment provides an oxidation pond system for treating livestock breeding wastewater, which is the same as that in Embodiment 1, except that the stirring part only includes a first expansion part, a second expansion part and a long stirring paddle, with a ring of long stirring paddles arranged between two adjacent expansion parts.

[0068] Example 5

[0069] This embodiment provides an oxidation pond system for treating livestock breeding wastewater, which is the same as that in Embodiment 1, except that the stirring part only includes a first expansion part, a second expansion part and a short stirring paddle, with a ring of short stirring paddles arranged between two adjacent expansion parts.

[0070] Example 6

[0071] This embodiment provides an oxidation pond system for treating livestock breeding wastewater, which is the same as that in Embodiment 1, except that the ratio of the radius of the first bulge to the minor axis radius of the second bulge is 1:2.2.

[0072] Example 7

[0073] This embodiment provides an oxidation pond system for treating livestock breeding wastewater, which is the same as that in Embodiment 1, except that the ratio of the radius of the first bulge to the minor axis radius of the second bulge is 1:1.

[0074] Example 8

[0075] This embodiment provides an oxidation pond system for treating livestock breeding wastewater, which is the same as that in embodiment 1, except that the ratio of the length of the first bulge to the length of the second bulge is 1:2.7.

[0076] Example 9

[0077] This embodiment provides an oxidation pond system for treating livestock breeding wastewater, which is the same as that in Embodiment 1, except that the ratio of the length of the first bulge to the length of the second bulge is 1:1.5.

[0078] Example 10

[0079] This embodiment provides an oxidation pond system for treating livestock breeding wastewater, which is the same as that in Embodiment 1, except that the length ratio of the short stirring paddle to the long stirring paddle is 1:2.1.

[0080] Example 11

[0081] This embodiment provides an oxidation pond system for treating livestock breeding wastewater, which is the same as that in Embodiment 1, except that the length ratio of the short stirring paddle to the long stirring paddle is 1:2.2.

[0082] Example 12

[0083] This embodiment provides an oxidation pond system for treating livestock breeding wastewater, which is the same as that in Embodiment 1, except that the ratio of the minor axis radius of the second bulge to the length of the short stirring paddle is 1:1.3.

[0084] Example 13

[0085] This embodiment provides an oxidation pond system for treating livestock breeding wastewater, which is the same as that in Embodiment 1, except that the ratio of the minor axis radius of the second bulge to the length of the short stirring paddle is 1:1.

[0086] Example 14

[0087] This embodiment provides an oxidation pond system for treating livestock breeding wastewater, which is the same as that in embodiment 2, except that the stirring part is inclined and the central rod forms a 30° angle with the vertical direction.

[0088] Examples 3 to 14 are examples for studying the stability of the stirring section. The swing amplitude of the central rod is used as the measurement index. The swing amplitude is the maximum distance that the bottom end of the central rod deviates from the bottom end of the central rod when it is stationary during rotation. The measurements are obtained after taking pictures with a camera.

[0089] Table 1. Comparison of the stability of the stirring section in Examples 3 to 14

[0090] project Swing amplitude (cm) project Swing amplitude (cm) Example 1 2.0 Example 9 3.6 Example 3 7.3 Example 10 2.6 Example 4 5.6 Example 11 4.0 Example 5 4.9 Example 12 2.1 Example 6 2.4 Example 13 3.1 Example 7 3.2 Example 14 8.4 Example 8 2.5

[0091] As can be seen from the table above, the improvements made to the stirring section in this invention can effectively reduce the swing amplitude of the central rod, improve the overall stability of the stirring section during rotation, and avoid mechanical failures and damage to the motor shaft.

Claims

1. An oxidation pond system for treating livestock breeding wastewater, characterized in that, It includes solar panels, a buoyancy unit, a stirring unit, and an electrocoagulation unit. Several solar panels are mounted on the buoyancy unit and can float on the surface of the wastewater in the oxidation pond. Several motors of the stirring unit and the power supply of the electrocoagulation unit are mounted on the buoyancy unit and connected to the solar panels, so as to use solar energy to power the oxidation pond system. Several stirring sections of the stirring unit and several cathode and anode plates of the electrocoagulation unit extend downward into the oxidation pond and are submerged in the wastewater. Under stirring conditions, the wastewater is treated by electrocoagulation. Several aeration pipes are provided at the bottom of the oxidation pond. A stirring section and an aeration pipe are set between a pair of cathode and anode plates, which can be used to stir and aerate a single electrocoagulation area, thereby improving treatment efficiency.

2. The oxidation pond system according to claim 1, characterized in that, The buoyancy unit is a buoyancy plate that can float on the surface of wastewater; several solar panels are evenly arranged on the buoyancy plate and can all receive sunlight; the top of the stirring part passes through the buoyancy plate and is connected to the motor shaft on the buoyancy plate, with the stirring part and the motor corresponding one-to-one. The tops of both the cathode and anode plates are detachably connected to the lower surface of the buoyancy plate. The wires of the cathode plate pass through the buoyancy plate and are then connected to the positive terminal of the power supply; the wires of the anode plate pass through the buoyancy plate and are then connected to the negative terminal of the power supply to energize the electrode plates.

3. The oxidation pond system according to claim 2, characterized in that, The electrode plates below the buoyancy plate are parallel to each other and evenly distributed along the length of the buoyancy plate, with cathode plates and anode plates alternately arranged; the anode plate is an iron plate or an aluminum plate, and the cathode plate is a stainless steel plate or a graphite plate. The spacing between two adjacent electrode plates is equal, with a spacing of 20-30cm; a stirring section is set in the middle between the cathode and anode plates, and the aeration pipe is also located in the middle between the cathode and anode plates, so that stirring and aeration can be evenly applied within an electrocoagulation area.

4. The oxidation pond system according to claim 2, characterized in that, Several aeration pipes are parallel to each other and evenly distributed along the length of the buoyancy plate at the bottom of the oxidation pond; the two ends of the aeration pipes are close to the two opposite sides of the oxidation pond, and several aeration holes are evenly distributed on the upper surface of the aeration pipes; the main air pipe connects all the aeration pipes in parallel, and the air pump outside the oxidation pond supplies air to the aeration pipes.

5. The oxidation pond system according to claim 2, characterized in that, The stirring section is rod-shaped and inclined, which can push the buoyancy plate to move; adjacent stirring sections are inclined in opposite directions, which can push the buoyancy plate to move in opposite directions; the motor on the buoyancy plate is also tilted and fixed.

6. The oxidation pond system according to claim 5, characterized in that, The stirring part includes a central rod, several first bulging parts and several second bulging parts. The central rod is inclined. The first bulging parts are all located in the upper middle part of the central rod, and the second bulging parts are all located in the lower middle part of the central rod. The first bulging parts are circular, and the second bulging parts are elliptical. The major axis of the second bulging parts is parallel to the central rod. A ring of stirring paddles is provided between two adjacent first bulges, and a ring of stirring paddles is also provided between two adjacent second bulges to expand the stirring range.

7. The oxidation pond system according to claim 6, characterized in that, The central rod is surrounded by several support rods, which are evenly arranged along the circumference of the central rod. Several support rods protrude outward from the stirring part at the same position corresponding to the central rod, forming a first bulge or a second bulge. Except for the bulge, the other parts of the support rods are parallel to the central rod and form a bundle with the central rod.

8. The oxidation pond system according to claim 7, characterized in that, The side wall of the central rod is provided with a stirring paddle, and several stirring paddles in the same circle are evenly distributed along the circumference of the central rod and have the same height. The head of the agitator is connected to the central rod, and the tail extends outward toward the agitator. The agitator extends out from the gap between the support rods without affecting the support rods.

9. The oxidation pond system according to claim 8, characterized in that, The radius of the first bulge is the maximum vertical distance between the middle of the corresponding support rod and the central rod, and the minor axis radius of the second bulge is the maximum vertical distance between the middle of the corresponding support rod and the central rod; the lengths of both bulges are along the length direction of the central rod. The ratio of the radius of the first bulge to the minor axis radius of the second bulge is 1:(1.1-2.2); the ratio of the length of the first bulge to the length of the second bulge is 1:(1.6-2.7).

10. The oxidation pond system according to claim 9, characterized in that, Along the length of the mixing section, a ring of long stirring paddles and a ring of short stirring paddles are alternately arranged, with long stirring paddles at the very top and very bottom of the mixing section. The ratio of the length of the short agitator to the length of the long agitator is 1:(1.5-2.1); the ratio of the minor axis radius of the second bulge to the length of the short agitator is 1:(1.1-1.3).

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