Device and method for treating mine hydroxamic acid organic wastewater by dielectric barrier discharge synergistic catalyst

Abstract

The present invention discloses an apparatus and method for treating mine hydroxamic acid organic wastewater by dielectric barrier discharge in cooperation with a catalyst, which includes a water tank (1) with a cover, a gas blowing device (2) arranged outside the water tank, an inner quartz dielectric tube (3) and an outer quartz dielectric tube (5) that cross the water tank and are sleeved with each other, a conductive component (4) wrapped inside the inner quartz dielectric tube, an air inlet hole (7) arranged at one end of the outer quartz dielectric tube, and a grounding electrode (11) arranged on the water tank. In the present invention, a catalyst is put into the small hole area of the outer quartz dielectric tube in the organic wastewater of the water tank, the gas blowing device and an AC high-voltage power supply are turned on, the gas flow rate is adjusted to 20-35 L / min, the peak value of the AC voltage is 10 kV-14.5 kV, and the residence time is 10-42 min. The apparatus of the present invention has strong corrosion resistance and can efficiently degrade benzohydroxamic acid wastewater. When the input voltage increases from 13 kV to 14.5 kV, the degradation efficiency of benzohydroxamic acid also increases significantly, reaching 98.7%.

Description

Technical Field

[0001] The present invention belongs to the technical field of wastewater treatment, and particularly relates to a device and method for treating organic wastewater of hydroxamic acid in mines by dielectric barrier discharge synergistic catalyst. Background Art

[0002] Hydroxamic acid is a flotation collector used in mineral flotation to enhance its capture ability and selectivity and improve the flotation effect, and has been widely used in mine flotation due to its capture effect. In recent years, a series of new hydroxamic acid modified collectors have been developed by introducing single or multi-functional groups based on hydroxamic acid agents and applied in mine flotation. However, due to the toxicity of hydroxamic acid and the resulting eutrophication of water, the environmental pollution problems caused by the application of hydroxamic acid have become pain points in the application.

[0003] At present, the treatment methods for mine organic wastewater are as follows: The natural degradation method is the most commonly used treatment method for mine wastewater. By setting up a mine tailings pond to store sewage and allowing pollutants to degrade by themselves, but hydroxamic acid collectors are not completely degraded or hardly degraded naturally under natural conditions, and direct discharge will cause serious secondary pollution to the environment; The biodegradation method has low energy consumption, is environmentally friendly and economical, and can well treat easily degradable organic matters such as xanthate. However, hydroxamic acid contains a benzyl structure and is difficult to degrade under single-substrate conditions. Nutrients need to be added to the strains. However, the actual mine organic wastewater contains various heavy metals, which is not conducive to the cultivation of strains. A variety of inorganic ions reduce the activity of the catalyst or even deactivate it. Therefore, the degradation effect of treating hydroxamic acid mine wastewater by adding a catalyst alone does not meet the discharge requirements. It is necessary to research and develop a device and method for treating organic wastewater of hydroxamic acid in mines to treat the difficult-to-degrade organic wastewater of hydroxamic acid in mines with toxicity, strong corrosiveness, excessive heavy metals of various types, and high solution density. Summary of the Invention

[0004] The purpose of the present invention is to solve the deficiencies of the prior art and provide a device and method for treating organic wastewater of hydroxamic acid in mines by dielectric barrier discharge synergistic catalyst with high degradation efficiency, strong corrosion resistance and not affected by heavy metals.

[0005] The technical solution adopted by the present invention is as follows:

[0006] Device for treating mine hydroxamic acid organic wastewater by dielectric barrier discharge synergistic catalyst, comprising a water tank with a cover, a gas blowing device arranged outside the water tank, an inner quartz dielectric tube and an outer quartz dielectric tube which cross the water tank and are sleeved with each other, a conductive component wrapped inside the inner quartz dielectric tube, an air inlet hole arranged at one end of the outer quartz dielectric tube, and a grounding electrode arranged on the water tank; a cavity between the inner wall of the outer quartz dielectric tube and the outer wall of the inner quartz dielectric tube forms a discharge area, both ends of the inner quartz dielectric tube and the outer quartz dielectric tube are arranged outside the water tank and are closed at both ends, a group of small holes are opened on the outer quartz dielectric tube located inside the water tank, the gas blowing device is communicated with the air inlet hole through a pipeline, and the conductive component and the water tank are connected to an AC high-voltage power supply through a wire.

[0007] Further, the inner quartz dielectric tube and the outer quartz dielectric tube are coaxially arranged.

[0008] Further, the group of small holes are evenly distributed at the bottom of the outer quartz dielectric tube.

[0009] Further, the device further comprises a monitoring device arranged on the wire to obtain circuit parameters.

[0010] A method for treating mine hydroxamic acid organic wastewater by using the device synergistic catalyst, adding hydroxamic acid organic wastewater containing hydroxamic acid and putting in catalyst activated carbon (boiling water, 5A molecular sieve, carbon nanotube) into the water tank of the device, putting the catalyst in the small hole area of the outer quartz dielectric tube, turning on the gas blowing device and the AC high-voltage power supply, adjusting the gas flow rate to 20 - 35 L / min, the peak value of the AC voltage to 13 kV - 14.5 kV, and the hydroxamic acid organic wastewater stays in the device for 10 - 42 min to complete the wastewater treatment.

[0011] Further, based on the volume of the treated wastewater, the catalyst addition amount is 0.5 - 2 g / L.

[0012] Further, the concentration of hydroxamic acid substances in the mine hydroxamic acid organic wastewater is 10 - 80 mg / L.

[0013] Further, the pH value of the mine hydroxamic acid organic wastewater is 8.

[0014] Advantages of the present invention:

[0015] The device of the present invention is provided with a double-layer quartz dielectric tube to protect the conductive component from contacting with the mine hydroxamic acid organic wastewater, and enhances the corrosion resistance of the device.

[0016] The organic wastewater of hydroxamic acid in mines has a high conductivity due to the excessive levels of various heavy metals. A high conductivity of the organic wastewater will significantly reduce the degradation effect. The discharge interval of the present invention is not in the organic wastewater but in the air, and the degradation effect is not affected by the conductivity of various heavy metals in the organic wastewater.

[0017] The active substances generated by low-temperature discharge plasma generally have a short effective time. In the present invention, the reaction interval of the catalyst is closely attached to the outer-layer dielectric quartz tube, and the active substances generated during discharge can be instantaneously contacted with the catalyst, improving the treatment efficiency of the organic wastewater. Brief Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of the device of the present invention;

[0019] Figure 2 It is a diagram of the degradation efficiency at different voltages in the embodiment of the present invention;

[0020] Figure 3 It is a diagram of the energy efficiency of the device for treating the hydroxamic acid wastewater in mines at different voltages in the embodiment of the present invention;

[0021] Figure 4 It is a diagram of the influence of lead and cadmium heavy metals on the degradation efficiency of the device for treating the hydroxamic acid wastewater in mines in the embodiment of the present invention. Embodiments

[0022] The content of the present invention will be further described below in conjunction with the drawings of the specification and the embodiments.

[0023] As Figure 1As shown in the figure, a device for treating organic wastewater containing hydroxamic acid in mines by dielectric barrier discharge synergistic catalyst includes a water tank 1 with a lid. The material of the water tank is acrylic. There is a gas blowing device 2 outside the water tank, an inner quartz dielectric tube 3 and an outer quartz dielectric tube 5 that cross the water tank and are sleeved with each other. The inner quartz dielectric tube and the outer quartz dielectric tube can be coaxially arranged. There is a conductive component 4 wrapped inside the inner quartz dielectric tube, an air inlet hole 7 arranged at one end of the outer quartz dielectric tube, and a grounding electrode 11 arranged on the water tank. The cavity between the inner wall of the outer quartz dielectric tube and the outer wall of the inner quartz dielectric tube forms a discharge area 6. The two ends of the inner quartz dielectric tube and the outer quartz dielectric tube are arranged outside the water tank and are closed at both ends. A group of small holes 8 are opened on the outer quartz dielectric tube located inside the water tank. The group of small holes can be evenly distributed at the bottom of the outer quartz dielectric tube. The gas blowing device is connected to the air inlet hole through a pipeline. The conductive component is connected to the water tank through a wire to access an AC high-voltage power supply 10. The AC high-voltage power supply can adopt a power frequency AC power supply (CTP-2000K) manufactured by Nanjing Suman Company. The device also includes a monitoring device 12 for obtaining circuit parameters on the wire. The monitoring device 12 includes a voltage probe (P6015A Tektronix), a capacitance low-voltage probe 0.47uf (TPP0201 Tektronix), a current probe (Model411 PEARSON), and a digital oscilloscope (DSOX4054A Agilent).

[0024] In this embodiment, the length of the water tank is 200mm, the width is 150mm, and the height is 150mm. The material is acrylic. A coaxial double-layer quartz dielectric circular tube crosses the water tank. The diameter of the outer quartz dielectric circular tube is 14mm, and the diameter of the inner quartz dielectric circular tube is 8mm. The lengths of the inner and outer quartz circular tubes are both 240mm, and the thicknesses are both 1mm and are closed at both ends. The inner wall of the outer quartz circular tube and the outer wall of the inner quartz circular tube form a symmetric discharge space discharge area 6. An air inlet hole 7 is opened at one end of the outer quartz circular tube. The inner quartz circular tube closely wraps the conductive component as the high-voltage electrode. The conductive component can be a steel threaded rod with an outer diameter of 8mm, a length of 260mm, and a pitch of 1mm. The grounding electrode 11 is a stainless steel threaded nail with a length of 15mm. Air enters the discharge area 6 from the air inlet hole of the outer quartz circular tube through the gas blowing device. By using 6-18 openings with a diameter of 1-2mm at the bottom of the outer quartz circular tube with the opening facing vertically downward, various active substances generated in the discharge area 6 are brought into the organic wastewater for degradation treatment. Example

[0025] Pour 1 L of benzyhydroxamic acid wastewater with a concentration of 80 mg / L into this device. Add 1.5 g / L of activated carbon catalyst in the small hole 9 area of the outer quartz dielectric tube. Adjust the wastewater pH to 8 with NaOH and HCl. Turn on the air-blowing equipment to adjust the flow rate to 30 L / min. Air is blown into the discharge area 6 through the air inlet hole 7, and then forms a water column through the small hole 8 at the bottom of the outer quartz dielectric tube 5 and enters the organic wastewater solution. Apply voltage to the high-voltage electrode conductive component 4, with an AC peak value of 13 kV and a current frequency of 7500 Hz. Every 7 minutes, open the water tank cover to take three groups of parallel samples, and sample 6 times. Use the high-performance liquid chromatograph (1260 Infinty Agilent) of Agilent Technologies to test the concentration of benzyhydroxamic acid. Example

[0026] Except for the initial stage of discharge, apply an AC peak value of 13.5 kV, and the rest of the operations are the same as in Example 1. Example

[0027] Except for the initial stage of discharge, apply an AC peak value of 14 kV, and the rest of the operations are the same as in Example 1. Example

[0028] In this example, 1 L of benzyhydroxamic acid wastewater with a concentration of 80 mg / L contains 5 mmol / l Pb(NO3)2, 10 mmol / l Pb(NO3)2, 5 mmol / l Cd(NO3)2, and 10 mmol / l Cd(NO3)2 respectively. Except for the initial stage of discharge, apply an AC peak value of 14.5 kV, and the rest of the operations are the same as in Example 1.

[0029] As Figure 2 shown, after 42 minutes of treatment of benzyhydroxamic acid wastewater in this device, the degradation efficiencies of Examples 1-4 are all greater than 90%. Using the device and method of the present invention can efficiently degrade benzyhydroxamic acid wastewater. When the input voltage increases from 13 kV to 14.5 kV, the degradation efficiency of benzyhydroxamic acid also increases significantly, reaching a maximum of 98.7%. As the input voltage increases, the active substances such as ozone and hydroxyl radicals generated by the dielectric barrier discharge device also gradually increase, improving the degradation efficiency. However, considering economic benefits, the present invention uses monitoring equipment to count the energy consumption as Figure 3 shown, and the highest energy efficiency is 0.633 mg / kWh in Example

[0030] From Figure 4It can be seen that the initial degradation efficiency of benzyhydroxamic acid mine wastewater without heavy metal ions is 93.57%. After the addition of heavy metal ions, the degradation efficiency of benzyhydroxamic acid increases. The highest degradation efficiency of benzyhydroxamic acid mine wastewater reaches 98.68%. The discharge area of the present invention in air will not affect the discharge high-voltage electrode and conductivity, and heavy metal ions will not inhibit the degradation of mine wastewater by dielectric barrier discharge synergistic catalyst.

[0031] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. An apparatus for treating organic wastewater of hydroxamic acid type in mines by dielectric barrier discharge synergistic catalyst, characterized in that, It includes a water tank (1) with a lid, an air-blowing device (2) arranged outside the water tank, an inner-layer quartz dielectric tube (3) and an outer-layer quartz dielectric tube (5) which cross the water tank and are sleeved with each other, a conductive component (4) wrapped inside the inner-layer quartz dielectric tube, an air inlet hole (7) arranged at one end of the outer-layer quartz dielectric tube, and a grounding electrode (11) arranged on the water tank; a cavity between the inner wall of the outer-layer quartz dielectric tube and the outer wall of the inner-layer quartz dielectric tube forms a discharge area (6), both ends of the inner-layer quartz dielectric tube and the outer-layer quartz dielectric tube are arranged outside the water tank and are closed at both ends, a group of small holes (8) are opened in the outer-layer quartz dielectric tube located inside the water tank, the small holes of the outer-layer quartz dielectric tube are evenly distributed at the bottom to form a water column, the catalyst is placed in the small hole area of the outer-layer quartz dielectric tube, the air-blowing device is communicated with the air inlet hole through a pipeline, and the conductive component and the water tank are connected to an AC high-voltage power supply (10) through a wire.

2. The device for treating mine hydroxamic acid organic wastewater by dielectric barrier discharge synergistic catalyst according to claim 1, wherein The inner-layer quartz dielectric tube and the outer-layer quartz dielectric tube are coaxially arranged.

3. The device for treating hydroxamic acid organic wastewater from mines by dielectric barrier discharge and catalyst according to claim 1, characterized in that: The group of small holes are evenly distributed at the bottom of the outer-layer quartz dielectric tube.

4. The device for treating mine hydroxamic acid organic wastewater by dielectric barrier discharge synergistic catalyst according to claim 1, wherein The device further includes a monitoring device (12) arranged on the wire to obtain circuit parameters.

5. A method for treating mine hydroxamic acid organic wastewater by using the device according to any one of claims 1-4 in cooperation with a catalyst, characterized in that, Add the organic wastewater containing hydroxamic acid and put in the catalyst into the water tank of the device, turn on the air-blowing device and the AC high-voltage power supply, adjust the air flow rate to 20 - 35 L / min, and the peak value of the AC voltage to 13 kV - 14.5 kV. The organic wastewater containing hydroxamic acid stays in the device for 10 - 42 min to complete the wastewater treatment.

6. The method according to claim 5, characterized in that, Based on the volume of the treated wastewater, the catalyst addition amount is 0.5 - 2 g / L.

7. The method according to claim 5, characterized in that, The concentration of the hydroxamic acid substance in the organic wastewater of the mine containing hydroxamic acid is 10 - 100 mg / L, and the wastewater temperature is 15 - 40 °C.

8. The method according to claim 5, wherein The pH value of the organic wastewater of the mine containing hydroxamic acid is 8.

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