Persulfate advanced oxidation reaction device based on mechanical-ultrasonic synergistic activation

Abstract

A persulfate advanced oxidation reaction device based on mechanical-ultrasonic synergistic activation comprises a reactor main body, a persulfate adding device and a catalyst adding device, the reactor main body adopts a structural design of a cylinder at the upper part and a cone at the lower part, and is internally provided with an anchor-paddle composite water impeller, a filler layer, a persulfate distributor and a catalyst distributor; an ultrasonic device and an overflow weir are arranged on the outer wall of the reactor body, a strong shear flow field and an ultrasonic cavitation field are constructed through the synergistic effect of anchor-paddle composite plug flow and the ultrasonic device, and efficient activation of persulfate and a catalyst is achieved. The device has the advantages of high solid-liquid mass transfer efficiency, high catalyst utilization rate, low operation energy consumption, remarkable sludge reduction effect and the like, and is particularly suitable for treating degradation-resistant organic wastewater such as antibiotics and the like.

Description

Technical Field

[0001] The utility model belongs to the technical field of sewage treatment, and specifically relates to a persulfate advanced oxidation reaction device based on mechanical-ultrasonic synergistic activation, which is particularly suitable for the treatment of difficult-to-degrade organic wastewater such as antibiotics. Background Art

[0002] At present, the treatment technologies for difficult-to-degrade organic pollutants such as antibiotics mainly include physical and chemical methods and biological treatment methods. The commonly used physical and chemical methods include adsorption, coagulation and chemical oxidation. The adsorbent in water treatment technology is usually activated carbon, but whether it is powdered activated carbon or granular activated carbon, its adsorption effect is closely related to factors such as pollutant concentration and water quality background conditions. Although the coagulation method is simple to operate, the removal effect of the coagulant on the target pollutant is very unsatisfactory, and the amount of coagulant used is large, which produces a large amount of sludge. Although adsorption and coagulation methods can remove some pollutants to a certain extent, they only transfer them and do not completely degrade them. Therefore, it is still necessary to completely degrade and remove the target pollutants through chemical oxidation.

[0003] Advanced oxidation processes can attack target pollutants through a series of chain reactions triggered by free radicals, degrading them into H2O and CO2, thereby reducing secondary pollution. Advanced oxidation methods also have great application prospects due to their high efficiency, rapidity, and thorough oxidation reactions. In recent years, persulfate-based advanced oxidation technologies have received increasing attention. Compared with traditional advanced oxidation technologies, they have the following advantages: higher free radical production, a wider range of activation methods, better adaptability to operating parameters (such as peroxide dosage) and water background (such as pH, coexisting ions, etc.), and easier transportation and storage of persulfate. Therefore, persulfate-based advanced oxidation technologies have broader application prospects in wastewater treatment.

[0004] Existing persulfate reactors have a stirring dead zone (accounting for about 15-20% of the total volume), which leads to serious catalyst deposition and a catalyst utilization rate of less than 60%. Alternatively, they use a simple ultrasonic activation method, resulting in high energy consumption (2.5-3.8 kWh of electricity per ton of water) and a sharp drop in the treatment effect on high-concentration wastewater (COD>2000 mg / L). Utility Model Content

[0005] In response to the shortcomings of the existing technology, the utility model designs an anchor-propeller composite flow-pushing device and an ultrasonic device to work together to construct a strong shear flow field and an ultrasonic cavitation field, thereby improving the efficiency of treating wastewater containing difficult-to-degrade organic matter and improving the effluent water quality.

[0006] The utility model adopts the following technical solution: a persulfate advanced oxidation reaction device based on mechanical-ultrasonic synergistic activation, comprising a reactor body, a persulfate adding device, and a catalyst adding device, characterized in that: the reactor body is an upper cylindrical / lower conical structure, a water inlet is provided on the top, and a composite flow propeller composed of an anchor stirrer and a three-blade paddle stirrer is configured inside; a packing layer is filled above the interior of the reactor body, a persulfate distributor and a catalyst distributor are provided below the packing layer; an ultrasonic device and an overflow weir are provided on the outer wall of the reactor body; the persulfate adding device comprises a persulfate storage tank and a persulfate metering pump; and the catalyst adding device comprises a catalyst storage tank and a catalyst metering pump.

[0007] Furthermore, the upper part of the reactor body is cylindrical with a height-to-diameter ratio of 2:1-4:1, the lower part is conical with a cone angle of 45-75°, and a polytetrafluoroethylene anti-corrosion layer is provided on the inner wall.

[0008] Furthermore, the composite flow propeller is driven by a motor with a rotation speed of 30-200 rp / min, the anchor agitator is adapted to the conical structure at the bottom of the reactor, and the gap between the anchor blade and the cone wall is 10-20 mm.

[0009] Furthermore, the filler layer is filled with ceramsite with a diameter of 5-10 mm and a filling height of 3-50 cm.

[0010] Furthermore, the number of the ultrasonic devices is 4-8, which are arranged at equal intervals along the axis of the reactor, with an operating frequency of 20-100 kHz and a power density of 0.1-1.0 W / cm 3 .

[0011] Furthermore, the inlet end of the persulfate metering pump is connected to the persulfate storage tank, and the outlet end is connected to the persulfate distributor; the inlet end of the catalyst metering pump is connected to the catalyst storage tank, and the outlet end is connected to the catalyst distributor; the persulfate distributor and the catalyst distributor adopt an annular porous water distribution pipe.

[0012] The beneficial effects of the present invention are as follows: (1) The present invention forms a strong shear flow field by designing the bottom of the reactor in a conical shape and cooperating with an anchor agitator, which has a high solid-liquid mass transfer efficiency, can effectively prevent catalyst deposition, and improve catalyst utilization.

[0013] (2) The utility model designs an anchor propeller composite flow and an ultrasonic device to work together to construct a strong shear flow field and an ultrasonic cavitation field, thereby promoting the generation of more free radicals, thereby improving the efficiency of treating wastewater containing difficult-to-degrade organic matter and reducing operating energy consumption.

[0014] (3) The utility model generates less oxidation by-products and has a significant sludge reduction effect, which is beneficial to controlling secondary pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the process flow chart of this utility model.

[0016] Figure 2 This is a schematic diagram of the fluid flow in the persulfate advanced oxidation reactor of the present invention.

[0017] Figure: 1. Water inlet, 2. Anchor-propeller composite flowmaker, 21. Anchor agitator, 22. Three-blade paddle agitator, 3. Packing layer, 4. Motor, 5. Overflow weir, 6. Ultrasonic device, 7. Persulfate distributor, 8. Catalyst distributor, 9. Mud discharge port, 10. Persulfate storage tank, 11. Persulfate metering pump, 12. Catalyst storage tank, 13. Catalyst metering pump. DETAILED DESCRIPTION

[0018] The present invention will be described in detail below with reference to the embodiments and accompanying drawings.

[0019] like Figure 1 As shown, a persulfate advanced oxidation reaction device based on mechanical-ultrasonic synergistic activation includes a reactor body, a persulfate adding device, and a catalyst adding device, characterized in that: the reactor body is an upper cylindrical / lower conical structure, a water inlet 1 is provided on the top, and a composite flow propeller 2 composed of an anchor stirrer 21 and a three-blade paddle stirrer 22 is configured inside, a packing layer 3 is filled above the interior of the reactor body, and a persulfate distributor 7 and a catalyst distributor 8 are provided below the packing layer 3, an ultrasonic device 6 and an overflow weir 5 are provided on the outer wall of the reactor body, the persulfate adding device includes a persulfate storage tank 10 and a persulfate metering pump 11, and the catalyst adding device includes a catalyst storage tank 12 and a catalyst metering pump 13.

[0020] Wherein, the upper part of the reactor body is a cylinder with a height-to-diameter ratio of 2:1-4:1, the lower part is a cone with a cone angle of 45-75°, and a polytetrafluoroethylene anti-corrosion layer is provided on the inner wall. The composite flow propeller 2 is driven by a motor 4 with a rotation speed of 30-200 rp / min, the anchor agitator 21 is adapted to the conical structure of the lower part of the reactor, and the gap between the anchor blade and the cone wall is 10-20 mm. The packing layer 3 is filled with ceramsite with a diameter of 5-10 mm, a porosity of 40-45%, and a filling height of 3-50 cm. There are 4-8 ultrasonic devices 6, which are arranged at equal intervals along the axis of the reactor, with an operating frequency of 20-100 kHz and a power density of 0.1-1.0 W / cm 3The inlet end of the persulfate metering pump 11 is connected with the persulfate storage tank 10, and the outlet end is connected with the persulfate distributor 7; the inlet end of the catalyst metering pump 13 is connected with the catalyst storage tank 12, and the outlet end is connected with the catalyst distributor 8; the persulfate distributor 7 and the catalyst distributor 8 adopt annular porous water distribution pipes and are located at a position 20-30 cm below the filler layer 3, so that the persulfate and the catalyst are put into the reaction active area.

[0021] In operation, the wastewater to be treated enters the reactor from the water inlet 1, the persulfate oxidant is added into the reactor by the persulfate metering pump 11 through the persulfate distributor 7, and the catalyst is added into the reactor by the catalyst metering pump 13 through the catalyst distributor 8; under the action of the anchor propeller composite plug flow device 2 and the ultrasonic device 6, the wastewater is uniformly mixed with the persulfate and the catalyst and fully reacts; when the reaction proceeds to a certain extent (the residence time of the wastewater in the reactor is about 15-30 minutes), the supernatant gradually rises to the height of the overflow weir (the overflow weir 5 is 10-15 cm higher than the filler layer 3) under the pushing of the continuous water inlet (the water inlet flow is 0.5-2 m 3 / h), at this time, the supernatant with smaller density is preferentially discharged through the overflow weir 5 to the subsequent treatment unit (the wastewater flow direction is shown in Figure 2 The filler layer 3 plays a buffering and blocking role, and the ceramic particles filled therein can intercept part of the suspended solids, particulate matter, silt and other impurities in the water. The sludge generated in the reactor is discharged from the sludge discharge port 9 regularly, once every 8 hours, for 5-10 minutes each time, so as to prevent the distributor from being blocked, and the discharged sludge is dewatered in the sludge treatment unit and then is transported out for harmless disposal.

[0022] The above describes the technical scheme of the present application in detail, but is not limited to the protection scope of the present application, and the ordinary skilled in the art can make improvements and modifications on the basis of the above, but these improvements and modifications are within the protection scope of the claims of the present application.

Claims

1. A persulfate advanced oxidation reaction device based on mechanical-ultrasonic synergistic activation, comprising a reactor body, a persulfate addition device, and a catalyst addition device, characterized in that: The reactor body is an upper cylindrical / lower conical structure with a water inlet on the top and a composite flow propeller composed of an anchor stirrer and a three-blade paddle stirrer. A packing layer is installed above the interior of the reactor body, and a persulfate distributor and a catalyst distributor are provided below the packing layer. An ultrasonic device and an overflow weir are provided on the outer wall of the reactor body. The persulfate addition device includes a persulfate storage tank and a persulfate metering pump. The catalyst addition device includes a catalyst storage tank and a catalyst metering pump.

2. The persulfate advanced oxidation reaction device based on mechanical-ultrasonic synergistic activation according to claim 1, characterized in that: The upper part of the reactor body is cylindrical with a height-to-diameter ratio of 2:1-4:1, the lower part is conical with a cone angle of 45-75 degrees, and a polytetrafluoroethylene anti-corrosion layer is provided on the inner wall.

3. The persulfate advanced oxidation reaction device based on mechanical-ultrasonic synergistic activation according to claim 1, characterized in that: The composite flow propeller is driven by a motor with a rotation speed of 30-200 rp / min. The anchor stirrer is adapted to the conical structure at the bottom of the reactor, and the gap between the anchor blade and the cone wall is 10-20 mm.

4. The persulfate advanced oxidation reaction device based on mechanical-ultrasonic synergistic activation according to claim 1, characterized in that: The packing layer is filled with ceramsite with a diameter of 5-10 mm and a filling height of 3-50 cm.

5. The persulfate advanced oxidation reaction device based on mechanical-ultrasonic synergistic activation according to claim 1, characterized in that: The number of ultrasonic devices is 4-8, which are evenly spaced along the axis of the reactor, with an operating frequency of 20-100 kHz and a power density of 0.1-1.0 W / cm 3 .

6. The persulfate advanced oxidation reaction device based on mechanical-ultrasonic synergistic activation according to claim 1, characterized in that: The inlet end of the persulfate metering pump is connected to the persulfate storage tank, and the outlet end is connected to the persulfate distributor. The inlet end of the catalyst metering pump is connected to the catalyst storage tank, and the outlet end is connected to the catalyst distributor. The persulfate distributor and the catalyst distributor adopt an annular porous water distribution pipe.

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