Sewage treatment device and method based on ozone bubble-free aeration

Abstract

The invention provides a sewage treatment device and method based on ozone bubble-free aeration, and relates to the technical field of sewage treatment based on ozone bubble-free aeration, the device comprises a hollow fiber membrane contactor, the hollow fiber membrane contactor comprises a shell and a hollow fiber membrane module arranged in the shell, the shell is provided with a gas inlet, a liquid inlet, a gas outlet and a liquid outlet, the gas inlet and the gas outlet are connected with a tube pass of the hollow fiber membrane contactor, and the liquid inlet is connected with a shell pass of the hollow fiber membrane contactor; the input end and the output end of the ozone generator are respectively connected with the oxygen supply part and the gas inlet; the liquid inlet component and the hydrogen peroxide adding component are connected with the liquid inlet; the problems of low mass transfer rate and high energy consumption and cost of an ozone aeration technology in the prior art are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment by ozone bubbleless aeration, and more specifically, relates to a sewage treatment device and method based on ozone bubbleless aeration. Background Art

[0002] With the increasingly strict industrial wastewater discharge standards, industrial wastewater, industrial park wastewater, etc. all need to be deeply treated to reduce the pollutant concentration in the wastewater, especially the refractory organic matter (CODcr). Usually, advanced oxidation processes such as ozone and Fenton are used to remove it. Compared with Fenton-based advanced oxidation technologies, ozone advanced oxidation technology does not introduce other ions or pollutants, does not require excessive adjustment of the pH of water, and has almost no secondary pollution. It is widely used in the deep treatment of refractory industrial wastewater. However, the utilization rate of existing ozone aeration technologies is low, and there are technical bottlenecks such as system instability and high costs. The process of ozone oxidizing organic matter in water is a series of multi-step reactions composed of gas-liquid mass transfer and chemical reactions. The whole reaction process is controlled by mass transfer, and the reaction rate depends on the mass transfer rate from the ozone gas phase to the liquid phase. Traditional ozone bubble reactors use titanium plates for aeration, and the size of the generated ozone bubbles is generally in the centimeter range, with a low mass transfer rate, which limits the improvement of the ozone oxidation reaction rate. At the same time, traditional ozone advanced oxidation membrane treatment devices often require power supply for electrocatalysis and coupled electrolysis to occur ozone catalytic oxidation reactions, consuming a large amount of electrical energy. Summary of the Invention

[0003] The purpose of the present invention is to address the deficiencies in the prior art and provide a sewage treatment device and method based on ozone bubbleless aeration to solve the problems of low mass transfer rate, high energy consumption, and high cost in the existing ozone aeration technology.

[0004] To achieve the above purpose, the present invention provides a sewage treatment device based on ozone bubbleless aeration, which includes:

[0005] A hollow fiber membrane contactor, the hollow fiber membrane contactor includes a housing and a hollow fiber membrane module disposed in the housing. The housing is provided with a gas inlet, a liquid inlet, a gas outlet, and a liquid outlet. The gas inlet and the gas outlet are connected to the tube side of the hollow fiber membrane contactor, and the liquid inlet is connected to the shell side of the hollow fiber membrane contactor;

[0006] An ozone generator, the input end and the output end of the ozone generator are respectively connected to an oxygen supply component and the gas inlet;

[0007] A liquid inlet component and a hydrogen peroxide dosing component, the liquid inlet component and the hydrogen peroxide dosing component are connected to the liquid inlet.

[0008] Optionally, the liquid inlet component includes a raw water tank and a liquid inlet pipeline. An inlet water pump and a filter are arranged on the liquid inlet pipeline, and the hydrogen peroxide dosing component is connected to the liquid inlet pipeline.

[0009] Optionally, the filtration accuracy of the filter is 10 - 100 microns.

[0010] Optionally, a first pressure gauge, a first flowmeter, and a first regulating valve are arranged on the liquid inlet pipeline.

[0011] Optionally, the ozone generator is connected to the gas inlet through an ozone pipeline. An air pump, a second pressure gauge, and a second flowmeter are arranged on the ozone pipeline.

[0012] Optionally, it further includes a buffer tank. The buffer tank is provided with an oxygen inlet, an oxygen outlet, and a reflux inlet. The oxygen inlet is used to connect to an oxygen supply component. The oxygen outlet is connected to the input end through an oxygen pipeline. The reflux inlet is connected to the gas outlet through a reflux pipeline. A third pressure gauge and a second regulating valve are arranged on the reflux pipeline.

[0013] Optionally, the liquid outlet is connected to a liquid discharge pipeline. A fourth pressure gauge and a third regulating valve are arranged on the liquid discharge pipeline. The liquid discharge pipeline is connected to the raw water tank through a liquid discharge bypass. A fourth regulating valve is arranged on the liquid discharge bypass.

[0014] Optionally, the hollow fiber membrane of the hollow fiber membrane module is a hydrophobic porous membrane. The pore diameter of the hollow fiber membrane is 0.05um - 0.5um. The inner diameter of the hollow fiber membrane is 0.4mm - 0.8mm. The outer diameter of the hollow fiber membrane is 0.9 - 1.6mm. The porosity of the hollow fiber membrane is 40% - 70%. The breakthrough pressure of the hollow fiber membrane is 5.0bar - 10.0bar.

[0015] The present invention also provides a sewage treatment method based on ozone bubbleless aeration, using the above-mentioned sewage treatment device based on ozone bubbleless aeration. The method includes:

[0016] Inputting the ozone produced by the ozone generator into the tube side of the hollow fiber membrane contactor;

[0017] Inputting the sewage to be treated and hydrogen peroxide into the shell side of the hollow fiber membrane contactor through the liquid inlet component and the hydrogen peroxide dosing component;

[0018] Performing ozone bubbleless aeration treatment on the sewage to be treated through the hollow fiber membrane contactor, and discharging the treated sewage.

[0019] Optionally, it further includes:

[0020] Inputting the gas reacted in the hollow fiber membrane contactor into the buffer tank;

[0021] Input oxygen into the buffer tank;

[0022] Use the buffer tank to input oxygen into the input end of the ozone generator.

[0023] The present invention provides a sewage treatment device and method for ozone bubbleless aeration, and its beneficial effects are as follows: The sewage treatment device for ozone bubbleless aeration can produce ozone through an ozone generator and input the ozone into the tube side of a hollow fiber membrane contactor; input the sewage to be treated and hydrogen peroxide into the shell side of the hollow fiber membrane contactor through a liquid inlet component and a hydrogen peroxide dosing component; perform ozone bubbleless aeration treatment on the sewage to be treated through the hollow fiber membrane contactor, and the ozone gas enters the wastewater in a bubbleless aeration manner for mass transfer, fully reacts with the hydrogen peroxide added to the wastewater, undergoes an ozone catalytic oxidation reaction to generate ·OH, and degrades the organic matter in the wastewater; the sewage treatment device for ozone bubbleless aeration has a compact structure, good pressure resistance, a high packing density of the hollow fiber membrane module, a large specific surface area, and thus a large gas-liquid contact area, high mass transfer efficiency, and good mass transfer effect; at the same time, the sewage treatment device for ozone bubbleless aeration does not require power supply and electrocatalysis, can save electric energy, and reduce costs.

[0024] Other features and advantages of the present invention will be described in detail in the subsequent specific implementation part. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] By describing the exemplary embodiments of the present invention in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present invention will become more obvious, wherein, in the exemplary embodiments of the present invention, the same reference numerals generally represent the same components.

[0026] Figure 1 Shows a schematic structural diagram of a sewage treatment device based on ozone bubbleless aeration according to an embodiment of the present invention.

[0027] Figure 2 Shows a flowchart of a sewage treatment method based on ozone bubbleless aeration according to an embodiment of the present invention.

[0028] Description of the reference numerals:

[0029] 1. Hollow fiber membrane contactor; 2. Ozone generator; 3. Raw water tank; 4. Liquid inlet pipeline; 5. Feed water pump; 6. Filter; 7. First pressure gauge; 8. First flowmeter; 9. First regulating valve; 10. Ozone pipeline; 11. Air pump; 12. Second pressure gauge; 13. Second flowmeter; 14. Buffer tank; 15. Oxygen pipeline; 16. Return pipeline; 17. Third pressure gauge; 18. Second regulating valve; 19. Drainage pipeline; 20. Fourth pressure gauge; 21. Third regulating valve; 22. Drainage bypass; 23. Fourth regulating valve. Detailed Embodiment

[0030] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0031] As Figure 1 shown, the present invention provides a sewage treatment device based on ozone bubbleless aeration, and the device includes:

[0032] A hollow fiber membrane contactor 1, which includes a housing and a hollow fiber membrane module disposed inside the housing. The housing is provided with a gas inlet, a liquid inlet, a gas outlet and a liquid outlet. The gas inlet and the gas outlet are connected to the tube side of the hollow fiber membrane contactor 1, and the liquid inlet is connected to the shell side of the hollow fiber membrane contactor 1;

[0033] An ozone generator 2, the input end and the output end of the ozone generator 2 are respectively connected to an oxygen supply component and the gas inlet;

[0034] A liquid inlet component and a hydrogen peroxide dosing component, which are connected to the liquid inlet.

[0035] Specifically, to solve the problems of low mass transfer rate, high energy consumption and high cost in the existing ozone aeration technology; the sewage treatment device with ozone bubbleless aeration provided by the present invention can produce ozone through the ozone generator 2, and input the ozone into the tube side of the hollow fiber membrane contactor 1; input the sewage to be treated and hydrogen peroxide into the shell side of the hollow fiber membrane contactor 1 through the liquid inlet component and the hydrogen peroxide dosing component; perform ozone bubbleless aeration treatment on the sewage to be treated through the hollow fiber membrane contactor 1, and the ozone gas enters the wastewater in a bubbleless aeration manner for mass transfer, and fully reacts with the hydrogen peroxide added to the wastewater to undergo an ozone catalytic oxidation reaction to generate ·OH, which degrades the organic matter in the wastewater; the sewage treatment device with ozone bubbleless aeration has a compact structure, good pressure resistance, a high packing density of the hollow fiber membrane module, a large specific surface area, and thus a large gas-liquid contact area, high mass transfer efficiency and good mass transfer effect; at the same time, the sewage treatment device with ozone bubbleless aeration does not require power supply and electrocatalysis, can save electric energy and reduce costs.

[0036] Optionally, the liquid inlet component includes a raw water tank 3 and a liquid inlet pipeline 4. An inlet water pump 5 and a filter 6 are arranged on the liquid inlet pipeline 4, and the hydrogen peroxide dosing component is connected to the liquid inlet pipeline 4.

[0037] Specifically, the sewage to be treated in the original water tank 3 is first pumped into the filter 6 by the inlet water pump 5. The filtered water enters the hollow fiber membrane contactor 1, and hydrogen peroxide is added through the hydrogen peroxide dosing component before entering. The hollow fiber membrane contactor 1 adopts an external pressure structure, and the gas phase and liquid phase are respectively connected to the tube side and shell side of the hollow fiber membrane contactor 1.

[0038] Optionally, the filtration accuracy of the filter 6 is 10 - 100 microns.

[0039] Specifically, the filter 6 can adopt a bag filter 6 or a precision filter 6.

[0040] Optionally, a first pressure gauge 7, a first flow meter 8, and a first regulating valve 9 are provided on the liquid inlet pipeline 4.

[0041] Specifically, the first pressure gauge 7 and the first flow meter 8 are respectively used to measure the inlet water pressure and inlet water flow rate of the hollow fiber membrane contactor 1, and the first regulating valve 9 can adjust its inlet water.

[0042] Optionally, the ozone generator 2 is connected to the gas inlet through the ozone pipeline 10, and a gas pump 11, a second pressure gauge 12, and a second flow meter 13 are provided on the ozone pipeline 10.

[0043] Specifically, ozone is pumped into the hollow fiber membrane contactor 1 by the gas pump 11. The second pressure gauge 12 and the second flow meter 13 are respectively used to measure the inlet gas pressure and inlet gas flow rate of the hollow fiber membrane contactor 1. By controlling the frequencies of the inlet water pump 5 and the gas pump 11 and the first regulating valve 9, the flow rates and pressure differences of the gas-liquid two phases can be changed to ensure that the liquid phase pressure is greater than the gas phase pressure. The ozone gas enters the wastewater in a bubble-free aeration manner for mass transfer, reacts fully with the hydrogen peroxide added to the wastewater, undergoes an ozone catalytic oxidation reaction to generate ·OH, and degrades the organic matter in the wastewater.

[0044] Optionally, it further includes a buffer tank 14. The buffer tank 14 is provided with an oxygen inlet, an oxygen outlet, and a reflux inlet. The oxygen inlet is used to connect to an oxygen supplement component. The oxygen outlet is connected to the input end through an oxygen pipeline 15, and the reflux inlet is connected to the gas outlet through a reflux pipeline 16. A third pressure gauge 17 and a second regulating valve 18 are provided on the reflux pipeline 16.

[0045] Specifically, the ozone generator 2 uses oxygen as a gas source to generate ozone. The ozone is pumped out by the gas pump 11 and input into the hollow fiber membrane contactor 1. The tail gas discharged from the hollow fiber membrane contactor 1 has an oxygen content greater than 90% and an ozone content less than 1%. The tail gas flows through the third pressure gauge 17 and the second regulating valve 18 and enters the buffer tank 14, and new oxygen is appropriately supplemented to maintain a constant pressure in the buffer tank 14 and at the same time meet the pressure for entering the ozone generator 2. In this way, the ozone tail gas can be recycled to reduce the operating cost.

[0046] Optionally, a liquid discharge pipeline 19 is connected to the liquid outlet. A fourth pressure gauge 20 and a third regulating valve 21 are arranged on the liquid discharge pipeline 19. The liquid discharge pipeline 19 is connected to the original water tank 3 through a liquid discharge bypass 22, and a fourth regulating valve 23 is arranged on the liquid discharge bypass 22.

[0047] Specifically, after the treated sewage exits the hollow fiber membrane contactor 1, it is pressure-measured by the fourth pressure gauge 20, flows through the third regulating valve 21, and is discharged up to standard. If the treated sewage fails to meet the standard, the fourth regulating valve 23 is opened to make it flow into the original water tank 3 for further treatment until it meets the standard and is discharged.

[0048] Optionally, the hollow fiber membrane of the hollow fiber membrane module is a hydrophobic porous membrane. The pore diameter of the hollow fiber membrane is 0.05 μm to 0.5 μm, the inner diameter of the hollow fiber membrane is 0.4 mm to 0.8 mm, the outer diameter of the hollow fiber membrane is 0.9 to 1.6 mm, the porosity of the hollow fiber membrane is 40% to 70%, and the breakthrough pressure of the hollow fiber membrane is 5.0 bar to 10.0 bar.

[0049] Specifically, the hydrophobic porous membrane is used to separate the gas-liquid two-phase, and the hydrophobic porous membrane provides a gas-liquid mass transfer interface.

[0050] In this embodiment, the material of the hydrophobic porous membrane is polyvinylidene fluoride, polytetrafluoroethylene or polypropylene.

[0051] In this embodiment, the hollow fiber membrane module adopts an array weaving process, which is convenient for increasing local disturbance during the liquid phase flow process and greatly improving the gas-liquid mass transfer rate.

[0052] As Figure 2 shown, the present invention also provides a sewage treatment method based on ozone bubbleless aeration. Using the above-mentioned sewage treatment device based on ozone bubbleless aeration, the method includes:

[0053] Inputting the ozone produced by the ozone generator 2 into the tube side of the hollow fiber membrane contactor 1;

[0054] Inputting the sewage to be treated and hydrogen peroxide into the shell side of the hollow fiber membrane contactor 1 through the liquid inlet component and the hydrogen peroxide dosing component;

[0055] Performing ozone bubbleless aeration treatment on the sewage to be treated through the hollow fiber membrane contactor 1, and discharging the treated sewage.

[0056] Optionally, it further includes:

[0057] Inputting the gas reacted in the hollow fiber membrane contactor 1 into the buffer tank 14;

[0058] Inputting oxygen into the buffer tank 14;

[0059] Oxygen is input into the input end of the ozone generator 2 by using the buffer tank 14.

[0060] Optionally, the dosing ratio of hydrogen peroxide is O3:H2O2 = 2:1 to 3:1 (molar ratio).

[0061] In summary, for the sewage treatment method of ozone bubble-free aeration provided by the present invention, when in use, the above-mentioned sewage treatment device for ozone bubble-free aeration is utilized. Taking the biochemical effluent of a certain printing and dyeing factory with a CODcr of 300 mg / L as an example: First, the sewage to be treated is pumped into the filter 6 by the feed water pump 5. The filter 6 adopts a bag filter 6 with a filtration accuracy of 100 um. Next, the filtered sewage flows through the first flowmeter 8 and the second pressure gauge 12 into the shell side of the hollow fiber membrane contactor 1. Before entering, hydrogen peroxide is added through the hydrogen peroxide dosing component. The dosing ratio of hydrogen peroxide is O3:H2O2 = 2:1 (molar ratio). The hollow fiber membrane contactor 1 adopts an external pressure type structure. The material of the central control fiber membrane filament is polytetrafluoroethylene, with an average membrane pore size of 0.05 um, an inner diameter of 0.4 mm, an outer diameter of 0.9 mm, a porosity of 65%, and a breakthrough pressure of 5.0 bar to 10.0 bar. The packing density of the hollow fiber membrane contactor 1 is 1500 m 2 / m 3 ; The dosing ratio of ozone is O3:CODcr = 2:1 (mass ratio).

[0062] The ozone generator 2 uses oxygen as the gas source to generate ozone. The ozone flows through the air pump 11, the second flowmeter 13 and the second pressure gauge 12 into the tube side of the hollow fiber membrane contactor 1, enters the wastewater on the membrane surface (gas-liquid contact surface), and the tail gas discharged from the hollow fiber membrane contactor 1 has an oxygen content greater than 90% and an ozone content less than 1%. The tail gas flows through the third pressure gauge 17 and the second regulating valve 18 into the buffer tank 14. The tail gas and the newly added oxygen in the buffer tank 14 provide the gas source for the ozone generator 2.

[0063] The wastewater and ozone enter the hollow fiber membrane contactor 1. By controlling the operating frequencies of the feed water pump 5 and the air pump 11 and the regulating valves on both sides of the hollow fiber membrane contactor 1, the liquid phase pressure is 6.0 bar and the gas phase pressure is 4.0 bar. The ozone gas enters the wastewater in a bubble-free aeration manner for mass transfer, fully reacts with the hydrogen peroxide added to the wastewater, undergoes an ozone catalytic oxidation reaction to generate ·OH, degrades the organic matter in the wastewater, and the treated wastewater has a CODcr ≤ 80 mg / L and enters the subsequent treatment unit.

[0064] The above has described the embodiments of the present invention. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments.

Claims

1. A sewage treatment device based on ozone bubble-free aeration, characterized in that: The device includes: A hollow fiber membrane contactor, comprising a shell and a hollow fiber membrane assembly disposed in the shell, the shell being provided with a gas inlet, a liquid inlet, a gas outlet and a liquid outlet, the gas inlet and the gas outlet being connected to the tube side of the hollow fiber membrane contactor, and the liquid inlet being connected to the shell side of the hollow fiber membrane contactor; An ozone generator, wherein an input end and an output end of the ozone generator are respectively connected to an oxygen supply component and the gas inlet; A liquid inlet component and a hydrogen peroxide dosing component, wherein the liquid inlet component and the hydrogen peroxide dosing component are connected to the liquid inlet.

2. The sewage treatment device based on ozone bubble-free aeration according to claim 1 is characterized in that: The liquid inlet component comprises a raw water tank and a liquid inlet pipeline, a water inlet pump and a filter are arranged on the liquid inlet pipeline, and the hydrogen peroxide dosing component is connected to the liquid inlet pipeline.

3. The sewage treatment device based on ozone bubble-free aeration according to claim 2 is characterized in that: The filtering accuracy of the filter is 10-100 microns.

4. The sewage treatment device based on ozone bubble-free aeration according to claim 2 is characterized in that: The liquid inlet pipeline is provided with a first pressure gauge, a first flow meter and a first regulating valve.

5. The sewage treatment device based on ozone bubble-free aeration according to claim 1 is characterized in that: The ozone generator is connected to the gas inlet through an ozone pipeline, and an air pump, a second pressure gauge and a second flow meter are arranged on the ozone pipeline.

6. The sewage treatment device based on ozone bubble-free aeration according to claim 1 is characterized in that: It also includes a buffer tank, which is provided with an oxygen inlet, an oxygen outlet and a reflux inlet, the oxygen inlet is used to connect the oxygen replenishing component, the oxygen outlet is connected to the input end through an oxygen pipeline, the reflux inlet is connected to the gas outlet through a reflux pipeline, and the reflux pipeline is provided with a third pressure gauge and a second regulating valve.

7. The sewage treatment device based on ozone bubble-free aeration according to claim 2 is characterized in that: The liquid outlet is connected to a drainage pipeline, a fourth pressure gauge and a third regulating valve are arranged on the drainage pipeline, the drainage pipeline is connected to the raw water tank through a drainage bypass, and a fourth regulating valve is arranged on the drainage bypass.

8. The sewage treatment device based on ozone bubble-free aeration according to claim 1, characterized in that: The hollow fiber membrane of the hollow fiber membrane assembly is a hydrophobic porous membrane, the pore size of the hollow fiber membrane is 0.05um~0.5um, the inner diameter of the hollow fiber membrane is 0.4mm~0.8mm, the outer diameter of the hollow fiber membrane is 0.9~1.6mm, the porosity of the hollow fiber membrane is 40%~70%, and the penetration pressure of the hollow fiber membrane is 5.0bar~10.0bar.

9. A method for treating sewage based on ozone bubbleless aeration, using the sewage treatment device based on ozone bubbleless aeration according to any one of claims 1 to 8, characterized in that: The method includes: The ozone produced by the ozone generator is input into the tube side of the hollow fiber membrane contactor; The sewage to be treated and hydrogen peroxide are fed into the shell side of the hollow fiber membrane contactor through the liquid inlet component and the hydrogen peroxide dosing component; The wastewater to be treated is treated with ozone bubble-free aeration through a hollow fiber membrane contactor, and the treated wastewater is discharged.

10. The wastewater treatment method using ozone bubble-free aeration according to claim 9, characterized in that: Also includes: The reacted gas in the hollow fiber membrane contactor is input into a buffer tank; Input oxygen into the buffer tank; Oxygen is fed into the input of the ozone generator using a buffer tank.

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