Upflow electrocatalytic gas floatation device and wastewater treatment method

Abstract

The application relates to an upflow electro-catalytic gas floatation device and a wastewater treatment method. The device comprises, from bottom to top, an electro-catalytic oxidation three-dimensional electrode filler layer, a water outlet pipeline, a micro-nano bubble distribution plate, a water inlet distribution pipeline and a skimmer arranged in a treatment chamber. The device further comprises an internal reflux pipeline, which comprises an upper reflux section and a lower reflux section. An upper reverse cone and a lower reverse cone for separating floatage and wastewater are respectively arranged on the upper reflux section and the water outlet pipeline. The lower reflux section guides the wastewater separated by the upper reverse cone to the lower part of the electro-catalytic oxidation three-dimensional electrode filler layer. The device has high integration, small floor area, high wastewater treatment efficiency, and can improve the electro-catalytic oxidation efficiency and reduce the equipment operation and maintenance cost.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to an upflow electrocatalytic flotation device and a wastewater treatment method. Background Technology

[0002] Currently, air flotation and electrocatalytic oxidation technologies are widely used in wastewater treatment. Air flotation is a water treatment technology that uses air or other gases to generate microbubbles, which then adhere to suspended particles (such as suspended solids, oil droplets, and algae) in the water, forming a gas-particle complex with a density less than water. This complex then floats to the surface, achieving separation. Electrocatalytic oxidation is an advanced oxidation technology based on electrochemical principles. Through electrode reactions or catalysis, it generates highly oxidizing substances (such as hydroxyl radicals (OH), ozone (O3), and hydrogen peroxide (H2O2)) that directly oxidize and decompose organic pollutants in water into CO2, H2O, and harmless small molecules, or convert them into easily biodegradable substances.

[0003] However, most existing air flotation and electrocatalytic oxidation coupling devices are simple combinations of the two devices, which occupy a large area, have low wastewater treatment efficiency, high power consumption, and high electrode wear and maintenance costs. Summary of the Invention

[0004] To address the shortcomings of the existing technologies, the present invention aims to provide an upflow electrocatalytic flotation device and a wastewater treatment method. The device has high integration and a small footprint, and can fully realize the coupling of flotation and electrolytic catalytic oxidation technologies, thereby improving the quality of wastewater treatment. Furthermore, it can improve the efficiency of electrocatalytic oxidation and reduce equipment operation and maintenance costs.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] An upflow electrocatalytic flotation device includes a treatment chamber and an internal reflux pipeline. The treatment chamber is provided from bottom to top with an electrocatalytic oxidation three-dimensional electrode packing layer, an outlet pipeline, a micro-nano bubble gas distribution plate, an inlet water distribution pipeline, and a skimmer. The internal reflux pipeline includes an upper reflux section, a lower reflux section, and two side reflux sections connecting the upper reflux section and the lower reflux section.

[0007] The top wall of the upper reflux section is provided with an upper reverse cone. The upper reflux section is located directly above the water inlet distribution pipe. The bottom wall of the water inlet distribution pipe has multiple water outlet holes facing the upper surface of the micro-nano bubble distribution plate. The side wall of the lower reflux section has multiple water outlets located directly below the electrocatalytic oxidation three-dimensional electrode packing layer. The top wall of the water outlet pipe is provided with a lower reverse cone.

[0008] Preferably, both the upper and lower reverse cones include multiple parallel-arranged separate reverse cones. Each separate reverse cone includes a water collection port at the bottom, a cone body, and an open top. The water collection port is located on the side wall of the corresponding upper return section or outlet pipe and is connected to the inside of the pipe. The open tops are all vertically upward and have multiple upward-sloping water collection holes.

[0009] Preferably, the electrocatalytic oxidation three-dimensional electrode packing layer is provided with a DC power supply and several three-dimensional electrodes. All three-dimensional electrodes are arranged side by side and adjacent three-dimensional electrodes are connected to different electrodes of the DC power supply, forming multiple alternating anodes and cathodes for the electrocatalytic oxidation reaction.

[0010] Preferably, each of the three-dimensional electrodes includes a titanium alloy frame electrode and a conductive carbon fiber electrode. The titanium alloy frame electrode is a three-dimensional frame structure with an internal accommodating space made of titanium alloy wire mesh. The conductive carbon fiber electrode fills the internal accommodating space of the titanium alloy frame electrode. The conductive carbon fiber electrode is a multi-porous three-dimensional structure made of carbon fiber and carries a catalyst.

[0011] Preferably, the catalyst is iridium oxide or rubidium oxide.

[0012] Preferably, multiple aeration heads or releasers are uniformly arranged on the upper surface of the micro-nano bubble air distribution plate, and the aeration heads or releasers are arranged corresponding to the water outlet holes of the water inlet and water distribution pipe.

[0013] Preferably, a regulating valve is provided on the internal return pipeline.

[0014] Preferably, the skimmer includes a drive motor, a swing-arm skimmer plate installed on the inner top wall of the processing chamber, and a skimmer trough located below the swing-arm skimmer plate.

[0015] A wastewater treatment method, applied to the aforementioned upflow electrocatalytic flotation device, includes the following steps:

[0016] A catalytic electrolysis reaction occurs in the electrocatalytic oxidation three-dimensional electrode packing layer, generating rising gas that enters the micro-nano bubble gas distribution plate.

[0017] The first wastewater to be treated is introduced into the inlet water distribution pipe and flows out through the outlet hole at the bottom of the inlet water distribution pipe into the treatment chamber;

[0018] The micro-nano bubble air distribution plate converts the incoming gas into micro-nano bubbles. The micro-nano bubbles attach to the suspended particles in the first wastewater, thus initially demulsifying the emulsified oil in the first wastewater and forming the first scum. The first wastewater and the first scum rise together.

[0019] When passing through the upper reverse cone, the upper reverse cone separates the first wastewater from the first scum. The separated first scum continues to rise and is collected by the skimmer installed above. The first wastewater enters the inner return pipeline through the upper reverse cone and flows to the bottom of the electrocatalytic oxidation three-dimensional electrode packing layer.

[0020] The electrocatalytic oxidation three-dimensional electrode packing layer undergoes a catalytic electrolysis reaction to produce oxidizing substances, which oxidize and decompose the incoming first wastewater, decomposing the organic pollutants in the first wastewater. The generated bubbles rise to the surface and attach to the suspended particles in the first wastewater, forming a second scum.

[0021] The lower reverse cone separates the first wastewater from the second scum. The separated second scum continues to float upwards into the micro-nano bubble aeration plate, and the separated water is output through the outlet pipe.

[0022] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0023] 1) The upflow electrocatalytic flotation device designed in this invention uses a micro-nano bubble distribution plate, an electrocatalytic oxidation three-dimensional electrode packing layer, upper and lower reverse cones, and an internal reflux pipeline to first treat wastewater with flotation. Then, the wastewater undergoes a first scum separation through the upper reverse cone. The separated scum enters the electrocatalytic oxidation equipment through the internal reflux pipeline. This process, where wastewater undergoes flotation treatment before entering the electrocatalytic oxidation equipment, can improve the treatment efficiency of the electrocatalytic oxidation three-dimensional electrode equipment and extend its service life.

[0024] 2) The upflow electrocatalytic flotation device designed in this invention has an upper reverse cone that collects wastewater after flotation demulsification treatment and introduces it into an internal reflux pipeline. The wastewater flows through the internal reflux pipeline to the bottom of the electrocatalytic oxidation three-dimensional electrode packing layer. The bubbles generated by the electrocatalytic oxidation of the wastewater pass through the lower reverse cone and enter the micro-nano bubble gas distribution plate. The lower reverse cone collects the wastewater after electrocatalytic oxidation treatment and introduces it into the effluent pipeline, forming an energy-saving and efficient circulation treatment path. It can use the wastewater treated at different stages for gas and water distribution in the flotation device or as the electrolyte for electrolytic catalysis, saving the use and operating costs of the equipment.

[0025] 3) The upflow electrocatalytic flotation device designed in this invention is used to treat wastewater. The first wastewater entering the inlet water distribution pipe first makes full use of the micro-nano bubbles generated by electrolysis to perform flotation demulsification and flotation, removing waste substances such as oil in the water. The scum and wastewater are separated by the upper reverse cone. The resulting first wastewater is returned to the bottom electrocatalytic oxidation three-dimensional electrode packing layer through the internal return pipe, where direct and indirect oxidation-reduction reactions occur. Then, the scum and wastewater are separated again by the lower reverse cone. The resulting second wastewater has effectively removed waste substances and is discharged through the outlet pipe. The wastewater treatment effect is good and the equipment operating cost is low.

[0026] 4) The upflow electrocatalytic flotation device designed in this invention, when used to treat wastewater containing emulsified oil, can perform phase conversion on the emulsified oil in the first wastewater through a micro-nano bubble air distribution plate, transforming the emulsified oil into floating oil, and finally achieving oil-water separation, removing oil from the water, thereby degrading organic matter such as COD in the water. The reverse cone collection effectively separates floating oil and scum and treats the effluent, achieving clear effluent water quality.

[0027] 5) The upflow electrocatalytic flotation device designed in this invention integrates the degradation and removal of organic matter in wastewater with the transformation and removal of organic matter. The device has a high degree of integration, is easy to replicate and mass-produce. For large-scale water treatment, it can be manufactured in parallel with a short investment cycle and less on-site civil construction. Attached Figure Description

[0028] Figure 1 A schematic diagram of the structure of the upflow electrocatalytic flotation device proposed in Embodiment 1 is shown;

[0029] Figure 2 A schematic diagram of a single split reverse cone is shown;

[0030] Figure 3 A schematic diagram of the structure of the titanium alloy frame electrode is shown.

[0031] Figure 4 A schematic diagram of the three-dimensional electrode structure is shown.

[0032] The attached diagram is labeled as follows: 1. Treatment chamber; 2. Electrocatalytic oxidation three-dimensional electrode packing layer; 3. Micro-nano bubble aeration plate; 4. Inlet water distribution pipe; 5. Outlet water pipe; 6. Internal reflux pipe; 7. Upper reverse cone; 8. Lower reverse cone; 9. Skimmer; 21. DC power supply; 22. Three-dimensional electrode; 31. Aeration head; 61. Upper reflux section; 62. Lower reflux section; 63. Side reflux section; 91. Drive motor; 92. Swing arm skimmer; 93. Skimmer trough; 221. Titanium alloy frame electrode; 222. Conductive carbon fiber electrode; 71. Water collection port; 72. Cone body; 73. Cone top opening; 731. Water collection hole. Detailed Implementation

[0033] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0034] Example 1

[0035] like Figure 1As shown, this embodiment proposes an upflow electrocatalytic flotation device, including a sealed processing chamber 1. The processing chamber 1 contains an electrocatalytic oxidation three-dimensional electrode packing layer 2 and a micro / nano bubble distribution plate 3 located above the electrocatalytic oxidation three-dimensional electrode packing layer 2. The electrocatalytic oxidation three-dimensional electrode packing layer 2 includes a DC power supply 21 and several three-dimensional electrodes 22.

[0036] A water inlet pipe 4 is located directly above the micro-nano bubble aeration plate 3. The inlet of the water inlet pipe 4 is located outside the treatment chamber 1, introducing the first wastewater to be treated. The water inlet pipe 4 is parallel to the micro-nano bubble aeration plate 3 and has multiple outlet holes evenly distributed towards the upper surface of the micro-nano bubble aeration plate 3 to ensure uniform water distribution. Multiple aeration heads 31 are evenly distributed on the upper surface of the micro-nano bubble aeration plate 3. Preferably, each aeration head 31 corresponds one-to-one with the outlet hole of the water inlet pipe 4 to ensure effective water and air distribution.

[0037] The treatment chamber is also equipped with an internal reflux pipeline 6, which includes an upper reflux section 61 located directly above the inlet water distribution pipeline 4 and a lower reflux section 62 located directly below the three-dimensional electrode 22. The two ends of the upper reflux section 61 and the lower reflux section 62 are connected by two side reflux sections 63, forming a circulating reflux path. Several separation reverse cones with their bottoms connected to the upper reflux section 61 are evenly arranged on the upper reflux section 61, forming an upper reverse cone 7. Wastewater separated by the upper reverse cone 7 enters the internal reflux pipeline 6.

[0038] The aeration head 31 can also be replaced by a conventional wastewater treatment release device, preferably a V-shaped release device (conical or similar structure), which includes an open V-shaped container facing upwards. Wastewater flowing from the inlet distribution pipe 4 flows into the V-shaped container from above, encountering significant resistance. A water vortex is generated within the V-shaped structure, creating an upward flow with even greater resistance, preventing the water from flowing downwards. Simultaneously, the upward resistance of the gas between the aeration heads 31 is very small, thus the water flow is intercepted by the gas as it rises. Therefore, the upper water level will not flow directly downwards due to gravity; it must flow downwards through the internal return pipe 6, and the aeration heads 31 will not become clogged.

[0039] A water outlet pipe 5 is located directly below the micro-nano bubble air distribution plate 3. Several separation reverse cones with their bottoms connected to the water outlet pipe 5 are evenly arranged on the water outlet pipe 5, forming a lower reverse cone 8. Wastewater separated by the lower reverse cone 8 enters the water outlet pipe 5 and is then output as treated wastewater.

[0040] The upper-layer reverse cone 7 and the lower-layer reverse cone 8 both include multiple separate reverse cones arranged side by side, such as Figure 2As shown, each separating reverse cone includes a water collection port 71 at the bottom, a cone body 72, and a cone top opening 73. The water collection port 71 is located on the side wall of the corresponding upper return section 61 or outlet pipe 5 and is connected to the interior of the pipe. The cone top openings 73 are all vertically upward and have multiple upward-sloping water collection holes 731. Each separating reverse cone is the same size and shape, resembling a funnel. Since the cone top openings 73 are all vertically upward, the gaps between the upper parts of each layer of reverse cones are small. The rising water flow further increases the rising speed of the scum. After the water flow or scum passes through the evenly distributed separating reverse cones, the water flow velocity decreases. The scum in the water continues to rise due to inertia and is collected by the reverse opening. Because the water flow velocity is slower in the opening, the collected water flow avoids carrying scum, thus achieving thorough separation of scum and wastewater. The upward water flow is the result of bubble agitation; the bubbles have a lifting effect, agitating the water flow upward. This embodiment adopts a multi-point layout design of the separation reverse cone, which can fully separate the gas generated by electrolysis from the internal reflux wastewater. The included angle of the effluent reverse cone is ≤50°, preferably 45°, and the cone angle is arranged downward, resulting in more uniform effluent.

[0041] The upflow electrocatalytic flotation device in this embodiment is also equipped with a skimmer 9, which includes a drive motor 91, a swing-arm skimmer 92 installed on the inner top wall of the processing chamber 1, and a skimmer 93 located below the swing-arm skimmer 92.

[0042] like Figure 3 and Figure 4 As shown, the electrocatalytic oxidation three-dimensional electrode packing layer 2 of this embodiment is provided with a DC power supply 21 and several three-dimensional electrodes 22. All three-dimensional electrodes 22 are arranged side by side, and adjacent three-dimensional electrodes 22 are connected to different electrodes of the DC power supply 21, forming multiple alternating anodes and cathodes for the electrocatalytic oxidation reaction. The electrode spacing, i.e., the spacing between adjacent electrodes, is preferably 1 cm. The three-dimensional electrode 22 includes: a titanium alloy frame electrode 221, and a conductive carbon fiber electrode 222 with a catalyst immobilized inside the titanium alloy frame electrode 221. The conductive carbon fiber electrode 222 adopts a multi-pore structure, similar to the pore structure of a sponge, which increases the number of wastewater flow channels and enhances the probability of contact reaction. The interior is further filled with carbon fiber with a catalyst immobilized inside, filled with oxides such as iridium and rubidium as catalysts. Moreover, the micropores of the carbon fiber itself reach the nanometer level, which can achieve micropore adsorption and aggregation of surrounding organic matter, thereby achieving effective adsorption and removal of organic matter in water. The titanium alloy frame electrode 221 is a frame structure with internal housing space made of titanium alloy wire mesh layer.

[0043] Example 2

[0044] This embodiment proposes a wastewater treatment method applied to the upflow electrocatalytic flotation device described in Embodiment 1, comprising the following treatment process:

[0045] 1) The electrocatalytic oxidation of the three-dimensional electrode packing layer 2 involves a catalytic electrolysis reaction, generating rising gas that enters the micro / nano bubble gas distribution plate 3. The electrocatalytic oxidation of the three-dimensional electrode packing layer 2 is placed in the initial electrolyte.

[0046] 2) The first wastewater to be treated is introduced into the inlet water distribution pipe 4 and flows out through the outlet hole at the bottom of the inlet water distribution pipe 4 into the treatment chamber 1.

[0047] 3) The micro-nano bubble air distribution plate 3 converts the incoming gas into micro-nano bubbles. The micro-nano bubbles attach to the suspended particles in the first wastewater, including the initial demulsification of the emulsified oil in the first wastewater, forming the first scum. This water intake method enables the first wastewater to fully contact the micro-nano bubbles formed by CO2 and other gases generated in the catalytic electrolysis reaction, achieving a good initial demulsification effect and the air flotation effect formed by bubble adhesion. The first wastewater and the first scum rise together.

[0048] 4) When passing through the upper reverse cone 7, the upper reverse cone 7 separates the first scum and the first wastewater. The first scum continues to rise and is effectively collected and discharged outside the device by the skimmer 9 with a swing-arm skimmer plate 92. The first wastewater enters the inner return pipe 6 and flows to the bottom of the electrocatalytic oxidation three-dimensional electrode packing layer 2. Since the first wastewater enters the upper reverse cone first, the scum has been basically removed.

[0049] 5) The electrocatalytic oxidation three-dimensional electrode packing layer 2 undergoes a catalytic electrolysis reaction to produce oxidizing substances, such as hydroxyl radicals (OH), ozone (O3), and hydrogen peroxide (H2O2), which oxidize and decompose the incoming first wastewater, decomposing the organic pollutants in the first wastewater. The generated CO2 bubbles rise to the surface and attach to a very small amount of suspended particles in the first wastewater, forming a second scum. The first wastewater and the second scum rise together.

[0050] 6) When passing through the lower reverse cone 8, the lower reverse cone 8 separates the first wastewater and the second scum, and obtains the separated second scum and the second wastewater. The separated second scum continues to float to the micro-nano bubble air distribution plate 3. The water quality of the second wastewater is already relatively high. At this point, the emulsified oil, organic waste particles and other substances in the first wastewater have been basically treated. The second wastewater is output as treated water through the outlet pipe 5.

[0051] The water inlet distribution pipe 4 continuously introduces the first wastewater to be treated, and the above actions are repeated.

[0052] A regulating valve is installed on the water outlet pipe 5. The liquid level of the electrolytic catalyst can be raised by adjusting the regulating valve.

[0053] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0054] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An upflow electrocatalytic flotation device, characterized in that: It includes a treatment chamber (1) and an internal reflux pipeline (6). In the treatment chamber (1), from bottom to top, there are an electrocatalytic oxidation three-dimensional electrode packing layer (2), an outlet pipeline (5), a micro-nano bubble gas distribution plate (3), an inlet water distribution pipeline (4), and a skimmer (9). The internal reflux pipeline (6) includes an upper reflux section (61), a lower reflux section (62), and two side reflux sections (63) connecting the upper reflux section (61) and the lower reflux section (62). The top wall of the upper reflux section (61) is provided with an upper reverse cone (7). The upper reflux section (61) is located directly above the water inlet distribution pipe (4). The bottom wall of the water inlet distribution pipe (4) is provided with multiple water outlet holes facing the upper surface of the micro-nano bubble distribution plate (3). The side wall of the lower reflux section (62) is provided with multiple water outlets located directly below the electrocatalytic oxidation three-dimensional electrode packing layer (2). The top wall of the water outlet pipe (5) is provided with a lower reverse cone (8). The upper reverse cone (7) and the lower reverse cone (8) each include multiple separate reverse cones arranged side by side. Each separate reverse cone includes a water collection port (71) at the bottom of the cone, a cone body (72) and a cone top opening (73). The water collection port (71) is located on the side wall of the corresponding upper return section (61) or water outlet pipe (5) and is connected to the inside of the pipe. The cone top openings (73) are all vertically upward and have multiple upward-sloping water collection holes (731). The electrocatalytic oxidation three-dimensional electrode packing layer (2) is provided with a DC power supply (21) and a number of three-dimensional electrodes (22). All three-dimensional electrodes (22) are arranged side by side and adjacent three-dimensional electrodes (22) are connected to different electrodes of the DC power supply (21) to form multiple alternating anodes and cathodes for the electrocatalytic oxidation reaction. Each of the three-dimensional electrodes (22) includes a titanium alloy frame electrode (221) and a conductive carbon fiber electrode (222). The titanium alloy frame electrode (221) is a three-dimensional frame structure with internal storage space made of titanium alloy wire mesh. The conductive carbon fiber electrode (222) is filled in the internal storage space of the titanium alloy frame electrode (221). The conductive carbon fiber electrode (222) is a three-dimensional structure with multiple pores made of carbon fiber and carries a catalyst. The upper surface of the micro-nano bubble air distribution plate (3) is uniformly provided with multiple aeration heads (31) or releasers, and the aeration heads (31) or releasers are correspondingly set with the water outlet holes of the water inlet distribution pipe (4).

2. The upflow electrocatalytic flotation device according to claim 1, characterized in that: The catalyst is either iridium oxide or rubidium oxide.

3. The upflow electrocatalytic flotation device according to claim 1, characterized in that: The internal return pipeline (6) is equipped with a regulating valve.

4. The upflow electrocatalytic flotation device according to claim 1, characterized in that: The skimmer (9) includes a drive motor (91), a swing-arm skimmer (92) installed on the inner top wall of the processing chamber (1), and a skimmer trough (93) located below the swing-arm skimmer (92).

5. A wastewater treatment method, applied to the upflow electrocatalytic flotation device according to any one of claims 1-4, characterized in that, Including the following steps: A catalytic electrolysis reaction occurs in the electrocatalytic oxidation three-dimensional electrode packing layer (2), generating floating gas that rises into the micro-nano bubble gas distribution plate (3). The water inlet and distribution pipe (4) introduces the first wastewater to be treated, which flows out through the outlet hole at the bottom of the water inlet and distribution pipe (4) and enters the treatment chamber (1); The micro-nano bubble air distribution plate (3) converts the incoming gas into micro-nano bubbles. The micro-nano bubbles attach to the suspended particles in the first wastewater, and the emulsified oil in the first wastewater is initially demulsified to form the first scum. The first wastewater and the first scum rise together. When passing through the upper reverse cone (7), the upper reverse cone (7) separates the first wastewater from the first scum. The first scum continues to rise after separation and is collected by the skimmer (9) set above. The first wastewater enters the inner return pipe (6) through the upper reverse cone (7) and flows to the bottom of the electrocatalytic oxidation three-dimensional electrode packing layer (2). The electrocatalytic oxidation three-dimensional electrode packing layer (2) undergoes a catalytic electrolysis reaction to produce oxidizing substances, which oxidize and decompose the incoming first wastewater, decompose the organic pollutants in the first wastewater, and the generated bubbles float to the surface, attaching to the suspended particles in the first wastewater to form a second scum. The lower reverse cone (8) separates the first wastewater from the second scum. The separated second scum continues to float upward into the micro-nano bubble air distribution plate (3), and the separated water is output through the water outlet pipe (5).

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