Photocatalytic treatment device for printing and dyeing wastewater

Abstract

The photocatalytic treatment device comprises a first tank body, a first carbon tube filling layer, a first titanium dioxide photocatalyst, a first doser, a first ultraviolet light source, a second tank body, a second carbon tube filling layer, a second titanium dioxide photocatalyst, a second doser, a second ultraviolet light source, an outer circulating pump and a first COD (Chemical Oxygen Demand) detector. According to the device, when a first COD value is greater than a standard COD value, printing and dyeing wastewater discharged from a first liquid outlet pipe of a first tank body flows back into a second liquid inlet pipe of a second tank body through an external circulating pump, and a first doser controls the concentration value of EDTA-Fa in the first tank body to be 2-4 mol / L, so that a first carbon tube filling layer is regenerated; on one hand, when the treatment capacity of the first tank body is reduced, the second tank body is switched to treat the printing and dyeing wastewater in time, finally, the COD value of the printing and dyeing wastewater reaches the standard for discharge, on the other hand, the first carbon tube filling layer can be regenerated in time when the treatment capacity of the first tank body is reduced, and the effect of achieving two purposes at a time is achieved.

Description

Technical Field

[0001] The invention relates to the field of printing and dyeing wastewater treatment, in particular to a photocatalytic treatment device for printing and dyeing wastewater. Background Art

[0002] Printing and dyeing wastewater contains a variety of printing and dyeing auxiliaries, which makes the treatment of printing and dyeing wastewater difficult. Therefore, in the treatment process of printing and dyeing wastewater, how to improve the removal efficiency of the chemical oxygen demand (COD) of printing and dyeing wastewater becomes the key to treating printing and dyeing wastewater. Summary of the invention

[0003] The invention provides a photocatalytic treatment device for printing and dyeing wastewater, the main purpose of which is to overcome the defect of high COD concentration in the printing and dyeing wastewater.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions: A photocatalytic treatment device for printing and dyeing wastewater, comprising: a first tank body, into which the printing and dyeing wastewater enters through a first liquid inlet pipe of the first tank body, and the printing and dyeing wastewater is discharged through a first liquid outlet pipe of the first tank body; a first carbon tube filling layer, the first carbon tube filling layer being arranged in the first tank body, and the first carbon tube filling layer being used for absorbing organic pollutants in the printing and dyeing wastewater; A first titanium dioxide photocatalyst, wherein the first titanium dioxide photocatalyst is disposed on a portion of the first carbon tube filling layer, and the first titanium dioxide photocatalyst is used for oxidatively decomposing organic pollutants in the printing and dyeing wastewater; a first doser, the first doser being used to add hydrogen peroxide and EDTA-Fa into the first tank, the hydrogen peroxide being used to oxidatively decompose organic pollutants in the printing and dyeing wastewater, and the EDTA-Fa being mixed with the hydrogen peroxide to oxidatively decompose organic pollutants in the printing and dyeing wastewater; a first ultraviolet light source, the ultraviolet light source being used to emit ultraviolet light and irradiate the hydrogen peroxide and the EDTA-Fa on the first titanium dioxide photocatalyst and the first carbon tube filling layer respectively; a second tank body, the printing and dyeing wastewater enters the second tank body through a second liquid inlet pipe of the second tank body, and the printing and dyeing wastewater is discharged through a second liquid outlet pipe of the second tank body; a second carbon tube filling layer, the second carbon tube filling layer being arranged in the second tank body, and the second carbon tube filling layer being used for absorbing the printing and dyeing wastewater; A second titanium dioxide photocatalyst, wherein the second titanium dioxide photocatalyst is disposed on a portion of the second carbon tube filling layer, and the second titanium dioxide photocatalyst is used to decompose organic pollutants in the printing and dyeing wastewater; A second doser, the second doser is used to add hydrogen peroxide and EDTA-Fa into the second tank, the hydrogen peroxide is used to oxidize and decompose organic pollutants in the printing and dyeing wastewater, and the EDTA-Fa is mixed with the hydrogen peroxide to oxidize and decompose organic pollutants in the printing and dyeing wastewater; a second ultraviolet light source, which is used to emit ultraviolet light and irradiate the hydrogen peroxide and the EDTA-Fa on the second titanium dioxide photocatalyst and the second carbon tube filling layer respectively; a first COD detector, the first COD detector being used to detect a first COD value of the printing and dyeing wastewater discharged from the first liquid outlet pipe; and External circulation pump; The printing and dyeing wastewater in the first tank is mixed with the first carbon tube filling layer, the first titanium dioxide photocatalyst, hydrogen peroxide and EDTA-Fa respectively, and the printing and dyeing wastewater in the second tank is mixed with the second carbon tube filling layer, the second titanium dioxide photocatalyst, hydrogen peroxide and EDTA-Fa respectively. Among them, when the first COD value is greater than the standard COD value, the printing and dyeing wastewater discharged from the first liquid outlet pipe flows back into the second liquid inlet pipe through the external circulation pump, and the first doser controls the concentration of EDTA-Fa in the first tank body to 2-4 mol / L, so that the first carbon tube filling layer is regenerated.

[0005] Compared with the prior art, the beneficial effects produced by the present invention are: The invention has a simple structure and strong practicality. When the first COD value is greater than the standard COD value, the printing and dyeing wastewater discharged from the first liquid outlet pipe of the first tank body flows back into the second liquid inlet pipe of the second tank body through the external circulation pump. The first doser controls the concentration value of EDTA-Fa in the first tank body to be 2-4 mol / L, so that the first carbon tube filling layer is regenerated. On the one hand, when the processing capacity of the first tank body decreases, the printing and dyeing wastewater is promptly switched to the second tank body for processing, and the COD value of the printing and dyeing wastewater is finally discharged up to the standard. On the other hand, when the processing capacity of the first tank body decreases, the first carbon tube filling layer can be promptly regenerated, achieving the effect of killing two birds with one stone. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 This is a schematic diagram of the structure of a photocatalytic printing and dyeing wastewater treatment device.

[0007] Figure 2 This is a module diagram of the first tank.

[0008] Figure 3 This is the module diagram of the second tank.

[0009] Figure 4Schematic diagram of effluent COD at a hydraulic retention time of 20 minutes and 40 minutes.

[0010] Figure 5 Schematic diagram of COD removal rate at hydraulic retention time of 20 minutes and 40 minutes.

[0011] Figure 6 Schematic diagram of the cumulative COD adsorption at a hydraulic retention time of 20 minutes and 40 minutes.

[0012] Figure 7 Schematic diagram of the cumulative COD adsorption at a hydraulic retention time of 20 minutes and 40 minutes.

[0013] Figure 8 Schematic diagram of activated carbon oxidation regeneration factor.

[0014] Fig. 9 Schematic diagram of activated carbon oxidation regeneration time.

[0015] Fig.10 This is a schematic diagram of the average inflow CODmg / L over three days.

[0016] Fig.11 Schematic diagram of the three-day column effluent COD mg / L and COD removal rate.

[0017] Fig.12 This is a schematic diagram of the column outflow SSg / L and SS removal rate on the first day. Implementation

[0018] The specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0019] To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0020] Unless otherwise defined, the technical or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the invention belongs. The words "first", "second" and similar terms used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Inside", "outside", "upper", "lower" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. "Multiple" means at least two.

[0021] Embodiment 1, refer to Figure 1 and Figure 2 A photocatalytic treatment device for printing and dyeing wastewater includes a first tank body 10, a first carbon tube filling layer 11, a first titanium dioxide photocatalyst 12, a first dosing device 14, a first ultraviolet light source 13, a second tank body 20, a second carbon tube filling layer 22, a second titanium dioxide photocatalyst 23, a second dosing device 24, a second ultraviolet light source 21, an external circulation pump 25 and a first COD detector 32.

[0022] Reference Figure 1 and Figure 2 The printing and dyeing wastewater enters the first tank body 10 through the first liquid inlet pipe 15 of the first tank body 10 , and is discharged through the first liquid outlet pipe 16 of the first tank body 10 .

[0023] Reference Figure 1 and Figure 2 The first carbon tube filling layer 11 is disposed in the first tank body 10 , and the first carbon tube filling layer 11 is used to adsorb organic pollutants in the printing and dyeing wastewater.

[0024] Reference Figure 1 and Figure 2 The first titanium dioxide photocatalyst 12 is disposed on a portion of the first carbon tube filling layer 11 , and the first titanium dioxide photocatalyst 12 is used for oxidatively decomposing organic pollutants in the printing and dyeing wastewater.

[0025] Reference Figure 1 and Figure 2 The first doser 14 is used to add hydrogen peroxide and EDTA-Fa into the first tank 10. The hydrogen peroxide is used to oxidize and decompose organic pollutants in the printing and dyeing wastewater. The EDTA-Fa is mixed with the hydrogen peroxide to oxidize and decompose organic pollutants in the printing and dyeing wastewater.

[0026] Reference Figure 1 and Figure 2 The ultraviolet light source is used to emit ultraviolet light and irradiate the hydrogen peroxide and EDTA-Fa on the first titanium dioxide photocatalyst 12 and the first carbon tube filling layer 11 respectively.

[0027] Reference Figure 1 and Figure 2 The printing and dyeing wastewater enters the second tank body 20 through the second liquid inlet pipe 30 of the second tank body 20 , and is discharged through the second liquid outlet pipe 31 of the second tank body 20 .

[0028] Reference Figure 1 and Figure 2 The second carbon tube filling layer 22 is disposed in the second tank body 20, and the second carbon tube filling layer 22 is used for absorbing printing and dyeing wastewater.

[0029] Reference Figure 1 and Figure 2The second titanium dioxide photocatalyst 23 is disposed on a portion of the second carbon tube filling layer 22, and the second titanium dioxide photocatalyst 23 is used to decompose organic pollutants in the printing and dyeing wastewater.

[0030] Reference Figure 1 and Figure 2 The second doser 24 is used to add hydrogen peroxide and EDTA-Fa into the second tank 20. The hydrogen peroxide is used to oxidize and decompose organic pollutants in the printing and dyeing wastewater. The EDTA-Fa is mixed with the hydrogen peroxide to oxidize and decompose organic pollutants in the printing and dyeing wastewater.

[0031] Reference Figure 1 and Figure 2 The second ultraviolet light source 21 is used to emit ultraviolet light and irradiate the hydrogen peroxide and EDTA-Fa on the second titanium dioxide photocatalyst 23 and the second carbon tube filling layer 22 respectively; the ultraviolet light can be 300nm ultraviolet light.

[0032] Reference Figure 1 and Figure 2 The first COD detector 32 is used to detect the first COD value of the printing and dyeing wastewater discharged from the first liquid outlet pipe 16; the printing and dyeing wastewater in the first tank body 10 is mixed with the first carbon tube filling layer 11, the first titanium dioxide photocatalyst 12, hydrogen peroxide and EDTA-Fa respectively, and the printing and dyeing wastewater in the second tank body 20 is mixed with the second carbon tube filling layer 22, the second titanium dioxide photocatalyst 23, hydrogen peroxide and EDTA-Fa respectively. When the first COD value is greater than the standard COD value, the printing and dyeing wastewater discharged from the first liquid outlet pipe 16 flows back to the second liquid inlet pipe 30 through the external circulation pump 25, and the first doser 14 controls the concentration of EDTA-Fa in the first tank body 10 to be 2-4 mol / L, so that the first carbon tube filling layer 11 is regenerated.

[0033] Reference Figure 1 and Figure 2 When the first COD value is less than the standard COD value, the first doser 14 controls the concentration of EDTA-Fa in the first tank 10 to be 0-2 mol / L, and the printing and dyeing wastewater discharged from the second liquid outlet pipe 31 flows back to the first liquid inlet pipe 15 through the external circulation pump 25, so that the second carbon tube filling layer 22 is regenerated.

[0034] Reference Figure 1 and Figure 2By setting that when the first COD value is greater than the standard COD value, the printing and dyeing wastewater discharged from the first liquid outlet pipe 16 flows back to the second liquid inlet pipe 30 through the external circulation pump 25, and the first doser 14 controls the concentration of EDTA-Fa in the first tank body 10 to be 2-4 mol / L, so that the first carbon tube filling layer 11 is regenerated. On the one hand, when the treatment capacity of the first tank body 10 decreases, it is switched to the second tank body 20 in time to treat the printing and dyeing wastewater, and finally the COD value of the printing and dyeing wastewater meets the discharge standard. On the other hand, when the treatment capacity of the first tank body 10 decreases, the first carbon tube filling layer 11 can be regenerated in time, achieving the effect of killing two birds with one stone.

[0035] Reference Figure 1 and Figure 2 The reaction mechanism is as follows: after hydrogen peroxide is irradiated by ultraviolet light emitted by an ultraviolet light source (the first ultraviolet light source 13 or the second ultraviolet light source 21), the oxygen-oxygen bond of hydrogen peroxide is broken, and self-decomposition produces hydroxyl free radicals to mineralize the organic pollutants in the printing and dyeing wastewater. EDTA-Fe can be oxidized by hydrogen peroxide, so that EDTA-Fe2+ in the circulating liquid 20 is converted into EDTA-Fe3+, and EDTA-Fe3+ is used to oxidize organic pollutants.

[0036] Example 2, refer to Figure 1 and Figure 2 The difference between the second embodiment and the first embodiment is that: a second COD detector 33 is provided on the second liquid outlet pipe 31, and the second COD detector 33 is used to detect the second COD value of the printing and dyeing wastewater discharged through the second liquid outlet pipe 31. When the second COD value is greater than the standard COD value, the second doser 24 controls the concentration of EDTA-Fa in the second tank body 20 to be 2-4 mol / L, and the printing and dyeing wastewater discharged from the second liquid outlet pipe 31 is refluxed into the first liquid inlet pipe 15 through the external circulation pump 25, so that the second carbon tube filling layer 22 is regenerated.

[0037] Reference Figure 1 and Figure 2 When the first COD value and the second COD value are both less than the standard COD value, the printing and dyeing wastewater enters the first tank body 10 through the first liquid inlet pipe 15 of the first tank body 10, and the printing and dyeing wastewater is discharged through the first liquid outlet pipe 16 of the first tank body 10, and the second tank body 20 is in a standby state.

[0038] Reference Figure 1 and Figure 2In this embodiment, when the second COD value is greater than the standard COD value, the printing and dyeing wastewater discharged from the second liquid outlet pipe 31 flows back to the first liquid inlet pipe 15 through the external circulation pump 25, and the second doser 24 controls the concentration of EDTA-Fa in the second tank body 20 to be 2-4 mol / L, so that the second carbon tube filling layer 22 is regenerated. On the one hand, when the processing capacity of the second tank body 20 decreases, it is switched to the first tank body 10 in time to treat the printing and dyeing wastewater, and finally the COD value of the printing and dyeing wastewater meets the discharge standard. On the other hand, when the processing capacity of the second tank body 20 decreases, the second carbon tube filling layer 22 can be regenerated in time, achieving the effect of killing two birds with one stone.

[0039] The other structures are similar to those of the first embodiment and will not be described in detail here.

[0040] Example 3, refer to Figure 1 and Figure 2 The difference between the third embodiment and the first embodiment is that: a first circulation pump 40 is arranged in the first tank body 10, and the first circulation pump 40 is arranged on the lower part of the first tank body 10. A plurality of first spray pipes 41 are arranged on the first circulation pump 40, and an adapted first spray pipe 41 is arranged on one side of each first carbon tube filling layer 11. The first spray pipe 41 is used to spray the liquid sucked by the first circulation pump 40 onto the first carbon tube filling layer 11 and the surface of the first titanium dioxide photocatalyst 12, respectively, so that the liquid circulates through the surface of the first titanium dioxide photocatalyst 12 and the surface of the first carbon tube filling layer 11 for multiple times, and the liquid is a mixture of hydrogen peroxide and EDTA-Fa.

[0041] Reference Figure 1 and Figure 2 A portion of the first spray pipe 41 is arranged on the outer side of the first tank body 10, and the liquid outlet pipe portion of the first spray pipe 41 passes through the outer shell of the first tank body 10 and extends into the first tank body 10. A plurality of first nozzles 42 are arranged at intervals on the liquid outlet pipe portion of the first spray pipe 41. The first nozzles 42 are used to spray liquid on the first carbon tube filling layer 11 and the first titanium dioxide photocatalyst 12. The liquid inlet pipe portion of the first spray pipe 41 is arranged on the liquid outlet of the first circulation pump 40.

[0042] Reference Figure 1 and Figure 2When the first circulation pump 40 sprays the mixed liquid on the first carbon tube filling layer 11 through the first spray pipe 41 for multiple cycles, a part of the mixed liquid is sprayed into the first carbon tube filling layer 11 and contacts with the printing and dyeing wastewater in the first carbon tube filling layer 11, a part of the hydrogen peroxide is used to oxidize the organic pollutants in the printing and dyeing wastewater, and another part of the hydrogen peroxide is used to oxidize EDTA-Fe so that the EDTA-Fe2+ in the mixed liquid is converted into EDTA-Fe3+, and EDTA-Fe3+ is used to oxidize the organic pollutants, thereby regenerating the activated carbon in the first carbon tube filling layer 11.

[0043] Reference Figure 1 and Figure 2 In this embodiment, by providing a first circulation pump 40 and a first spray pipe 41, the mixed liquid in the first tank body 10 is circulated through the surface of the first carbon tube filling layer 11 for multiple times, and the hydrogen peroxide and EDTA-Fe sprayed on the surface of the first carbon tube filling layer 11 can remove the organic pollutants in the printing and dyeing wastewater, thereby cleaning the first carbon tube filling layer 11 and maintaining the pore structure in the first carbon tube filling layer 11. The desorbed organic pollutants are directly removed by the circulating water, so that the first carbon tube filling layer 11 can be regenerated in time to maintain good adsorption performance.

[0044] Reference Figure 1 and Figure 2 When the first circulation pump 40 sprays at least a part of the mixed liquid on the surface of the first carbon tube filling layer 11 and the first titanium dioxide photocatalyst 12 through the first spray pipe 41 for multiple cycles, a part of the mixed liquid is sprayed into the first carbon tube filling layer 11 and contacts with the printing and dyeing wastewater in the first carbon tube filling layer 11, so that the first carbon tube filling layer 11 is regenerated, and another part of the mixed liquid is sprayed onto the first titanium dioxide photocatalyst 12 to form a catalyst and contacts with the printing and dyeing wastewater, so that the organic pollutants in the printing and dyeing wastewater are decomposed.

[0045] Reference Figure 1 and Figure 2In this embodiment, by providing a first circulation pump 40 and a first spray pipe 41, the mixed liquid in the tank body is circulated through the surface of the first titanium dioxide photocatalyst 12 and the surface of the first carbon tube filling layer 11 for multiple times, thereby increasing the contact area between the printing and dyeing wastewater and the first carbon tube filling layer 11 and the first titanium dioxide photocatalyst 12. On the one hand, the first titanium dioxide photocatalyst 12 is fully contacted with the printing and dyeing wastewater, thereby effectively decomposing the organic pollutants in the printing and dyeing wastewater, and the first carbon tube filling layer 11 is fully contacted with the printing and dyeing wastewater, thereby fully adsorbing the organic pollutants in the printing and dyeing wastewater, thereby reducing the COD value of the printing and dyeing wastewater. On the other hand, the mixed liquid is sprayed on the surface of the first carbon tube filling layer 11 multiple times to clean the first carbon tube filling layer 11, keep the pore structure in the first carbon tube filling layer 11 unobstructed, so that the first carbon tube filling layer 11 can be regenerated in time to maintain good adsorption performance. The desorbed organic pollutants are directly decomposed on the surface of the first titanium dioxide photocatalyst 12, which has the effect of serving two purposes.

[0046] Reference Figure 1 and Figure 2 In this embodiment, a first ultraviolet light source 13 is provided to emit ultraviolet light to irradiate the first titanium dioxide photocatalyst 12 (TiO2) for photocatalytic oxidation reaction, wherein the particle size of titanium dioxide is 25nm powder. On the one hand, hydrogen peroxide (hydrogen peroxide) and EDTA-Fe are combined to carry out chemical catalytic oxidation reaction to improve the efficiency of degrading organic pollutants. On the other hand, hydrogen peroxide and EDTA-Fe can also promote the regeneration of activated carbon in the first carbon tube filling layer 11, so that the first carbon tube filling layer 11 maintains a high adsorption efficiency, achieving the effect of killing two birds with one stone.

[0047] Reference Figure 1 and Figure 2 A second circulation pump 43 is provided in the second tank body 20, and the second circulation pump 43 is provided on the lower part of the second tank body 20. A plurality of second spray pipes 44 are provided on the second circulation pump 43. An adapted second spray pipe 44 is provided on one side of each second carbon tube filling layer 22. The second spray pipe 44 is used to spray the liquid sucked by the second circulation pump 43 onto the second carbon tube filling layer 22 and the surface of the second titanium dioxide photocatalyst 23, respectively, so that the liquid circulates through the surface of the second titanium dioxide photocatalyst 23 and the surface of the second carbon tube filling layer 22 for multiple times, and the liquid is a mixture of hydrogen peroxide and EDTA-Fa.

[0048] Reference Figure 1 and Figure 2A portion of the second spray pipe 44 is arranged on the outer side of the second tank body 20, and the liquid outlet pipe portion of the second spray pipe 44 passes through the outer shell of the second tank body 20 and extends into the second tank body 20. A plurality of second nozzles 45 are arranged at intervals on the liquid outlet pipe portion of the second spray pipe 44. The second nozzles 45 are used to spray liquid on the second carbon tube filling layer 22 and the second titanium dioxide photocatalyst 23. The liquid inlet pipe portion of the second spray pipe 44 is arranged on the liquid outlet of the second circulation pump 43.

[0049] Reference Figure 1 and Figure 2 When the second circulation pump 43 sprays the mixed liquid on the second carbon tube filling layer 22 through the second spray pipe 44 for multiple cycles, a part of the mixed liquid is sprayed into the second carbon tube filling layer 22 and contacts with the printing and dyeing wastewater in the second carbon tube filling layer 22, a part of the hydrogen peroxide is used to oxidize the organic pollutants in the printing and dyeing wastewater, and another part of the hydrogen peroxide is used to oxidize EDTA-Fe so that the EDTA-Fe2+ of the mixed liquid is converted into EDTA-Fe3+, and EDTA-Fe3+ is used to oxidize the organic pollutants, thereby regenerating the activated carbon in the second carbon tube filling layer 22.

[0050] Reference Figure 1 and Figure 2 In this embodiment, by providing a second circulation pump 43 and a second spray pipe 44, the mixed liquid in the second tank body 20 is circulated through the surface of the second carbon tube filling layer 22 for multiple times, and the hydrogen peroxide and EDTA-Fe sprayed on the surface of the second carbon tube filling layer 22 can remove the organic pollutants in the printing and dyeing wastewater, thereby cleaning the second carbon tube filling layer 22 and maintaining the pore structure in the second carbon tube filling layer 22. The desorbed organic pollutants are directly removed by the circulating water, so that the second carbon tube filling layer 22 can be regenerated in time to maintain good adsorption performance.

[0051] Reference Figure 1 and Figure 2 When the second circulation pump 43 sprays at least a part of the mixed liquid on the surface of the second carbon tube filling layer 22 and the second titanium dioxide photocatalyst 23 through the second spray pipe 44 for multiple cycles, a part of the mixed liquid is sprayed into the second carbon tube filling layer 22 and contacts with the printing and dyeing wastewater in the second carbon tube filling layer 22, so that the second carbon tube filling layer 22 is regenerated, and another part of the mixed liquid is sprayed onto the second titanium dioxide photocatalyst 23 to form a catalyst and contacts with the printing and dyeing wastewater, so that the organic pollutants in the printing and dyeing wastewater are decomposed.

[0052] Reference Figure 1 and Figure 2In this embodiment, by providing a second circulating pump 43 and a second spray pipe 44, the mixed liquid in the tank body is circulated through the surface of the second titanium dioxide photocatalyst 23 and the surface of the second carbon tube filling layer 22 for multiple times, thereby increasing the contact area between the printing and dyeing wastewater and the second carbon tube filling layer 22 and the second titanium dioxide photocatalyst 23. On the one hand, the second titanium dioxide photocatalyst 23 is fully contacted with the printing and dyeing wastewater, thereby effectively decomposing the organic pollutants in the printing and dyeing wastewater, and the second carbon tube filling layer 22 is fully contacted with the printing and dyeing wastewater, thereby fully adsorbing the organic pollutants in the printing and dyeing wastewater, thereby reducing the COD value of the printing and dyeing wastewater. On the other hand, the mixed liquid is sprayed on the surface of the second carbon tube filling layer 22 multiple times to clean the second carbon tube filling layer 22, keep the pore structure in the second carbon tube filling layer 22 unobstructed, so that the second carbon tube filling layer 22 can be regenerated in time to maintain good adsorption performance. The desorbed organic pollutants are directly decomposed on the surface of the second titanium dioxide photocatalyst 23, which has the effect of serving two purposes.

[0053] Reference Figure 1 and Figure 2 In this embodiment, a second ultraviolet light source 21 is provided to emit ultraviolet light to irradiate the second titanium dioxide photocatalyst 23 (TiO2) for photocatalytic oxidation reaction, wherein the particle size of titanium dioxide is 25nm powder. On the one hand, hydrogen peroxide (hydrogen peroxide) and EDTA-Fe are combined to carry out chemical catalytic oxidation reaction to improve the efficiency of degrading organic pollutants. On the other hand, hydrogen peroxide and EDTA-Fe can also promote the regeneration of activated carbon in the second carbon tube filling layer 22, so that the second carbon tube filling layer 22 can maintain a high adsorption efficiency, achieving the effect of killing two birds with one stone.

[0054] The other structures are similar to those of the first embodiment and will not be described in detail here.

[0055] Embodiment 4, referring to Figure 1 and Figure 2 The difference between the fourth embodiment and the first embodiment is that the first liquid outlet pipe 16 and the second liquid outlet pipe 31 are both connected to an intermediate pool 46, and the intermediate pool 46 is connected to the external circulation pump 25. When the first COD value is greater than the standard value, the printing and dyeing wastewater in the intermediate pool 46 flows back to the second liquid inlet pipe 30 through the external circulation pump 25. When the second COD value is greater than the standard value, the printing and dyeing wastewater in the intermediate pool 46 flows back to the first liquid inlet pipe 15 through the external circulation pump 25.

[0056] Reference Figure 1 and Figure 2 When the wastewater treatment device is under maintenance, the printing and dyeing wastewater is discharged into the intermediate pool 46.

[0057] The other structures are similar to those of the first embodiment and will not be described in detail here.

[0058] Example 5, refer to Figure 1 and Figure 2 The difference between the fifth embodiment and the first embodiment is that the concentration of EDTA-Fe is 0-8 mol / L, the hydrogen peroxide is 5.55%-5.6% hydrogen peroxide, when the COD value of the printing and dyeing wastewater discharged from the gas outlet 11 is less than 150 mg / L, the doser 14 controls the EDTA-Fe concentration in the tank body to be 0-2 mol / L, and when the COD value of the printing and dyeing wastewater discharged from the gas outlet 11 is greater than 150 mg / L, the doser 14 controls the EDTA-Fe concentration in the tank body to be 2-4 mol / L.

[0059] For example, the concentration of EDTA-Fe is 0, 1, 2, 3, 4, 5, 6, 7 or 8 mol / L, and the hydrogen peroxide is 5.55%, 5.56%, 5.57%, 5.58%, 5.59% or 5.6% hydrogen peroxide.

[0060] Ozone can also be introduced into the first tank through the first doser, and ozone can also be introduced into the second tank through the second doser.

[0061] The catalytic effect between hydrogen peroxide and ozone produces hydroxyl radicals, which more effectively promotes the conversion of EDTA-Fe2+ into EDTA-Fe3+. In addition, the substances introduced during the oxidation process react and decompose into water and oxygen, and no new impurities that require post-treatment are introduced.

[0062] Ozone is an oxidant and is combined with the first ultraviolet light source or the second ultraviolet light source to enhance the oxidative efficiency of ozone through ultraviolet rays.

[0063] In this embodiment, by introducing ozone into the first tank body or the second tank body, the proportion of macromolecular organic matter in the printing and dyeing wastewater is reduced, and the adsorption efficiency of the activated carbon is increased. At the same time, ozone can also enhance its oxidizing properties on the surface and inside of the activated carbon, decompose the organic matter adsorbed on the activated carbon, improve the oxidation efficiency of ozone, and accelerate the adsorption, regeneration and renewal speed of the activated carbon in the first carbon tube filling layer 13 and the second carbon tube filling layer 22, reduce the adsorption load borne by the activated carbon, increase the single use time of the activated carbon, and reduce the project investment and regeneration costs.

[0064] The other structures are similar to those of the first embodiment and will not be described in detail here.

[0065] Embodiment 6, the difference between the embodiment 6 and the embodiment 1 is that: the first carbon tube filling layer 11 and the second carbon tube filling layer 22 are activated carbon or rice husk activated carbon, the particle size of the activated carbon is 0.5-2 mm, for example: the particle size of the activated carbon is 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2 mm, the particle size of the rice husk activated carbon is 0.5-2 mm, for example: the particle size of the rice husk activated carbon is 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2 mm. 9 or 2mm, the hydraulic flow rate is set at 120mL / min to 140mL / min, for example: the hydraulic flow rate is set at 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139 or 140mL / min, and the hydraulic retention time is 20min to 40min, for example, the hydraulic retention time is 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39 or 40min.

[0066] The preparation of rice husk activated carbon includes the following steps: In step S01, the rice husks are first washed in clean water to remove powder and insects from the rice husks, and then dried in a drying oven.

[0067] Step S02, placing the rice husks processed in step S01 in a container, adding 0.1 mol of sodium hydroxide to soak, and stirring them with a stirrer for 2.5 to 3 hours, sieving them with a 10-mesh sieve, and drying them in a drying oven.

[0068] Step S03, then placing the rice husk treated in step S02 in a reactor, adding 1 mol of potassium hydroxide to soak at a temperature of 90-95° C. for 3.5-4 hours, sieving with a 35-mesh sieve, and drying in a drying oven to obtain activated rice husk.

[0069] Step S04, a plurality of pores are punched on the surface of the activated rice husk, and then the activated rice husk is placed in a high temperature furnace for oxygen-free calcination at a temperature of 830-850° C. for 4.5-5 hours to obtain carbonized rice husk.

[0070] Step S05, placing the carbonized rice husk in a reactor, adding pure water to soak at a temperature of 90-95°C for 3.5-4 hours, sieving with a 35-mesh sieve, and drying in a drying oven to obtain rice husk activated carbon.

[0071] The calculation formula for the adsorption capacity of activated carbon is: (1); CODads is the amount of activated carbon adsorbed in one day, BK_eff is the blank average outflow COD, Day1_AVE is the removal rate of the previous day, and Day2_AVE is the removal rate of the next day.

[0072] Reference Figure 4 The flow rate is 7.2L / hr, the vertical axis is the outflow COD, and the horizontal axis is the cumulative time (hr). The average inflow COD from the first day to the third day is about 262mg / L, 284mg / L, and 290mg / L. The wastewater inflow rate is 120mL / min and 240mL / min to control the hydraulic retention time, which is 40 minutes and 20 minutes respectively. Figure 5 The COD removal efficiency was almost zero at a flow rate of 240 mL / min in two days. The hydraulic retention time of 20 minutes for the 1,400 g activated carbon column was too short, so the effluent concentration dropped after one day. Figure 6 As shown, it was observed that the cumulative adsorption amount of 1,400g activated carbon at a flow rate of 120mL / min was about 52g, and the cumulative adsorption amount at a flow rate of 240mL / min was about 43g. A higher flow rate would reduce the adsorption amount of activated carbon, and a flow rate of 120mL / min was relatively appropriate.

[0073] The other structures are similar to those of the first embodiment and will not be described in detail here.

[0074] Embodiment 7. The difference between Embodiment 7 and Embodiment 1 is that: the mass of the first titanium dioxide photocatalyst 12 is 0.01-0.05 g, the mass of the second titanium dioxide photocatalyst 23 is 0.01-0.05 g, for example: the mass of the first titanium dioxide photocatalyst 12 is 0.01, 0.02, 0.03, 0.04 or 0.05 g, the mass of the second titanium dioxide photocatalyst 23 is 0.01, 0.02, 0.03, 0.04 or 0.05 g, the concentration of hydrogen peroxide is 0.26-0.68 mol / L, for example: the concentration of hydrogen peroxide is 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67 or 0.68, and the concentration of EDTA-Fe is 0.09-0.18 mol / L, for example: the concentration of EDTA-Fe is 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17 or 0.18 mol / L.

[0075] The effective factors of ultraviolet light degradation of organic pollutants through titanium dioxide photocatalyst, hydrogen peroxide and EDTA-Fa were tested experimentally. There are three kinds of organic pollutants involved in the experiment. The first one is activated carbon ID Red-114 (AR-114) (acid red), with the molecular formula of C37H28N4Na2O1S3, the second one is Reactive Bl activated carbon K-5 (RB-5) (activated black 5), with the molecular formula of C26H21N5Na4O19S6, and the third one is Disperse Bl activated carbon K- EX-SF (DB-EX-SF) (disperse black EX-SF), with the molecular formula of C22H19N6O6Br.

[0076] Experiment 1, testing the optimal dosage of titanium dioxide photocatalyst: First, the dosage of titanium dioxide photocatalyst is divided into 5 dosages, namely 0.01g, 0.025g, 0.05g, 0.1g, and 0.25g, and ultraviolet light is used for reaction. In the AR-114 and RB-5 reactions, the degradation rate of organic pollutants is measured by UV spectrophotometer. When the dosage of titanium dioxide photocatalyst is added at 0.05g, the degradation rate (degradation ratio) is 49.2% and 70.1% respectively. After that, the degradation rate has tended to be flat, and when the dosage is added more, its degradation rate gradually decreases. The reason is that when titanium dioxide photocatalyst is added to a certain dosage, the transmittance gradually decreases, so that the oxidizing power is also weakened. Therefore, the preferred dosage range of titanium dioxide photocatalyst is preferably 0 to 0.05g.

[0077] The range of 0-0.05g is evenly divided into five additive dosages, namely 0.01g, 0.02g, 0.03g, 0.04g, and 0.05g. These five dosages of titanium dioxide photocatalyst are then matched with the optimal dosage points of hydrogen peroxide and EDTA-Fe.

[0078] Experiment 2: Testing the optimal ratio of hydrogen peroxide and EDTA-Fe: First, 0, 0.09, 0.18, 0.27 and 0.36 mol / L EDTA-Fe and 0, 8.16, 16.32, 24.47 and 32.63 mol / L hydrogen peroxide were tested. Taking AR-114 as an example, as the amount of hydrogen peroxide and EDTA-Fe added increased, the degradation rate showed a better trend.

[0079] However, based on cost considerations, this embodiment tends to achieve a certain good degradation rate under the condition of using less dosage. The maximum degradation change of hydrogen peroxide is between 0-8.16mol / L hydrogen peroxide and 0.18-0.27mol / L EDTA-Fe, while the maximum degradation change of EDTA-Fe is between 0-0.09mol / L EDTA-Fe and 32.63mol / L hydrogen peroxide. Since this embodiment tends to degrade organic pollutants by photocatalytic oxidation reaction, and the holes generated by titanium dioxide photocatalyst are used for oxidation reaction, this embodiment selects the area with less hydrogen peroxide dosage, that is, the maximum degradation change of hydrogen peroxide.

[0080] The degradation rates of hydrogen peroxide doses of 0 mol / L and 8.16 mol / L are quite different. By combining different concentrations of hydrogen peroxide and EDTA-Fe, the degradation ratios (%) of different organic pollutants (AR-114) are obtained. When the hydrogen peroxide dose of 0.68 mol / L is added, the degradation trend is almost flat, and the degradation rate is not much different. For example, compared with 1.36 mol / L hydrogen peroxide, the degradation rate (78.1%) is only about 2% different; if compared with 0.34 mol / L hydrogen peroxide, the degradation rate (62.3%) is still 10-15% different. In this hydrogen peroxide dose (0.68 mol / L), the highest degradation rate is 75.9%, so the optimal dose of hydrogen peroxide and EDTA-Fe in the AR-114 results is selected as a combination of 0.68 mol / L hydrogen peroxide and 0.18 mol / L EDTA-Fe.

[0081] In this embodiment, compared with the degradation rate of 23.0% obtained by treating organic pollutants with only 0.68 mol / L hydrogen peroxide and the degradation rate of 16.9% obtained by treating organic pollutants with only 0.18 mol / L EDTA-Fe, the preferred dosage of hydrogen peroxide and EDTA-Fe selected in this embodiment is 0.68 mol / L hydrogen peroxide and 0.18 mol / L EDTA-Fe, and the degradation rate obtained is as high as 75.9%.

[0082] The degradation rate in 0.26mol / L hydrogen peroxide and 0.09mol / L EDTA-Fe is 72.5%. After this point, even if the dosage of hydrogen peroxide is increased, the degradation rate tends to be flat. Compared with the degradation rate of 0.13mol / L hydrogen peroxide, the difference is about 15%. Therefore, the preferred dosage of hydrogen peroxide and EDTA-Fe is selected as a combination of 0.26mol / L hydrogen peroxide and 0.09mol / L EDTA-Fe.

[0083] In another embodiment, compared with the degradation rate of 2.4% obtained by treating organic pollutants with only 0.26 mol / L hydrogen peroxide and the degradation rate of 9.0% obtained by treating organic pollutants with only 0.09 mol / L EDTA-Fe, the preferred dosage of hydrogen peroxide and EDTA-Fe selected in this embodiment is 0.26 mol / L hydrogen peroxide and 0.09 mol / L EDTA-Fe, and the degradation rate obtained is as high as 72.5%.

[0084] Experiment three, testing the ratio of titanium dioxide photocatalyst, hydrogen peroxide and EDTA-Fe: In this embodiment, 0.01g, 0.02g, 0.03g, 0.04g and 0.05g of titanium dioxide photocatalyst are used in combination with ultraviolet light for reaction, and the above-mentioned preferred ratios of hydrogen peroxide and EDA-Fe are combined to find the preferred ratio of titanium dioxide photocatalyst, hydrogen peroxide and EDTA-Fe with the highest degradation rate in the oxidation reaction of each organic pollutant. When the dosage of titanium dioxide photocatalyst is 0.04g, the degradation rate is 88.3%, which is more than 10% different from the degradation rate (75.9) of no titanium dioxide photocatalyst. Therefore, in the reaction of AR-114, 0.04g of titanium dioxide photocatalyst, 0.68mol / L of hydrogen peroxide and 0.18mol / L of EDTA-Fe are selected as the preferred ratio.

[0085] In the results of RB-5, the degradation effect was the best when the titanium dioxide photocatalyst was 0.01g, and the degradation rate was as high as 85.9%, which was more than 10% different from the degradation rate of the photocatalyst without titanium dioxide (72.5%). When the dosage of titanium dioxide photocatalyst was increased, its degradation rate gradually weakened, indicating that the increase in dosage had an inhibitory effect on the reaction. Therefore, 0.01g of titanium dioxide photocatalyst, 0.26mol / L of hydrogen peroxide and 0.09mol / L of EDTA-Fe were selected as the optimal ratio.

[0086] By setting up activated carbon, titanium dioxide photocatalyst, hydrogen peroxide and EDTA-Fa to treat organic pollution in printing and dyeing wastewater, and combining photocatalytic oxidation reaction and chemical catalytic oxidation reaction to treat organic pollutants, the dosage of substances required for related degradation can be greatly reduced.

[0087] Compared with the prior art, this embodiment has the following advantages: 1. This embodiment uses a lower dosage of substances (titanium dioxide photocatalyst and hydrogen peroxide dosage) to treat pollutants, which can significantly reduce the impact on the biological treatment system and also reduce the cost of treating organic pollutants.

[0088] 2. This embodiment combines activated carbon, titanium dioxide photocatalyst, hydrogen peroxide and EDTA-Fa, and finds a better ratio. The results show that the pollutant degradation efficiency of this embodiment can exceed the highest degradation efficiency achieved by a single oxidation technology, and its effect exceeds the sum of the two.

[0089] 3. This embodiment combines activated carbon, titanium dioxide photocatalyst, hydrogen peroxide and EDTA-Fa to further improve the efficiency of degrading organic pollutants, replace the need for chemicals with ultraviolet light, and reduce the amount of chemical reagents used.

[0090] The other structures are similar to those of the first embodiment and will not be described in detail here.

[0091] Embodiment 8: The difference between Embodiment 8 and Embodiment 1 is that: a plurality of first carbon tube filling layers 11 are arranged in a bottom-up order and in a transversely stacked manner in the tube body, and a plurality of second carbon tube filling layers 22 are arranged in a bottom-up order and in a transversely stacked manner in the tube body.

[0092] Alternatively, a plurality of first carbon tube filling layers 11 are arranged in a vertical stack from left to right in the tube body, and a plurality of second carbon tube filling layers 22 are arranged in a vertical stack from left to right in the tube body.

[0093] The other structures are similar to those of the first embodiment and will not be described in detail here.

[0094] Embodiment 9: The difference between the embodiment 9 and the embodiment 6 is that: The preparation of rice husk activated carbon includes the following steps: In step S01, the rice husks are first washed in clean water to remove powder and insects from the rice husks, and then dried in a drying oven.

[0095] Step S02, placing the rice husks processed in step S01 in a container, adding 0.1 mol of sodium hydroxide to soak, and stirring them with a stirrer for 2.5 hours. After completion, sieving them with a 10-mesh screen and drying them in a drying oven.

[0096] Step S03, then place the rice husk treated in step S02 in a reactor, add 1 mol of potassium hydroxide and soak at 90° C. for 3.5 hours. After completion, sieve with a 35-mesh sieve and dry in a drying oven to obtain activated rice husk.

[0097] Step S04, a plurality of pores are punched on the surface of the activated rice husk, and then the husk is placed in a high-temperature furnace for oxygen-free calcination at a temperature of 830° C. for 4.5 hours to obtain carbonized rice husk.

[0098] Step S05, placing the carbonized rice husk in a reactor, adding pure water to soak at 90°C for 3.5 hours, sieving with a 35-mesh sieve, and drying in a drying oven to obtain rice husk activated carbon.

[0099] The other structures are similar to those of the fifth embodiment and will not be described in detail here.

[0100] Embodiment 10: The difference between the embodiment 10 and the embodiment 6 is that the preparation of rice husk activated carbon comprises the following steps: In step S01, the rice husks are first washed in clean water to remove powder and insects from the rice husks, and then dried in a drying oven.

[0101] Step S02, placing the rice husks processed in step S01 in a container, adding 0.1 mol of sodium hydroxide to soak, and stirring them with a stirrer for 3 hours. After completion, sieving them with a 10-mesh sieve and drying them in a drying oven.

[0102] Step S03, then placing the rice husk treated in step S02 in a reactor, adding 1 mol of potassium hydroxide to soak at 94° C. for 4 hours, sieving with a 35-mesh sieve, and drying in a drying oven to obtain activated rice husk.

[0103] Step S04, a plurality of pores are punched on the surface of the activated rice husk, and then the activated rice husk is placed in a high temperature furnace for oxygen-free calcination at a temperature of 845° C. for 5 hours to obtain carbonized rice husk.

[0104] Step S05, placing the carbonized rice husk in a reactor, adding pure water to soak at 94°C for 4 hours, sieving with a 35-mesh sieve, and drying in a drying oven to obtain rice husk activated carbon.

[0105] The other structures are similar to those of the sixth embodiment and will not be described in detail here.

[0106] Embodiment 11: The difference between this embodiment 11 and embodiment 1 is that the regeneration rate of activated carbon is tested with printing and dyeing wastewater as the pollutant, and the calculation formula of the activated carbon regeneration rate is: , CR represents the removal rate of wastewater by the regenerated activated carbon group in 24 hours. CF represents the removal rate of wastewater by the fresh activated carbon in 24 hours, which is 71% in this experiment. The initial concentration of the wastewater is 297 mg / L. Figure 8 , Fig. 9 It can be observed that according to the formula The regeneration removal rate of 5.55% H2O2 oxidation was 79%, and the regeneration removal rate of 4mM EDTA-Fe was 84%. The regeneration rate of the combination of the two reached 85%, which was the best effect. 4mM EDTA-Fe and 5.55% H2O2 were used as the test regeneration time dosage. Figure 7 , it was observed that the highest regeneration rate was observed at a regeneration time of 1 hour.

[0107] The activated carbon column was set between the regulating tank and the biological tank to test the treatment efficiency after the activated carbon regeneration. Fig.10 , the flow rate is 7.2L / hr, the vertical axis is the outflow COD, the horizontal axis is the cumulative time (hr), and the chemical oxygen demand for three days is about 2,500mg / L. From the outflow concentration, it can be found that the outflow concentration has a gradual upward trend in the first 2 hours, and then decreases in the 4th hour. This is because the COD and SS in the regulating pool at 12 noon in the actual field are both decreasing. Fig.11 According to the formula It is known that within 4 hours, the total amount of COD adsorbed by the activated carbon column is about 62.26g on the first day, about 40.47g on the second day, and about 37.01g on the third day. Fig.12 It was found that the SS of the regulating pool tended to decrease over time and reached the lowest level in the 4th hour. The average SS of the blank column outflow was about 527g / L in 4 hours, and the average SS of the activated carbon column was about 60g / L. According to the formula A total of about 12.51 g of suspended solids were removed, with an average removal of about 87.5% of suspended solids.

[0108] The activated carbon column treats wastewater at the front end of the sewage treatment plant (average COD ~ 2,500mg / L), removing 50% of the influent COD in 4 hours of operation. However, it can be operated continuously for 50 hours at the back end to treat wastewater (average COD ~ 185mg / L), and its effluent exceeds the discharge standard by 140mg / L. In addition, the activated carbon column can remove 88% of the SS of the front end wastewater; 50% of the SS of the back end wastewater. 3. The regeneration conditions of activated carbon are to use 5.6% H2O2 and 4mM EDTA-Fe as reagents, and the reaction is 1 hour. 4. After regeneration with pure water, the adsorption amount of activated carbon is about 33% lower than that of the original activated carbon; but with oxidation regeneration, the adsorption amount of activated carbon decreases more slowly. It is not feasible to place it at the front end with a short adsorption time, a large amount of activated carbon, and an overly large tank. It is placed at the back end with an adsorption time of 50 hours, a smaller amount of activated carbon, and a tank size that is more suitable for actual field placement. The cost of regeneration reagents is also much less than that required at the front end.

[0109] The other structures are similar to those of the first embodiment and will not be described in detail here.

[0110] Table 1. Cumulative COD adsorption at hydraulic retention time of 20 min and 40 min. The above is only a specific implementation of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial changes to the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. A photocatalytic treatment device for printing and dyeing wastewater, characterized in that: include: a first tank body, into which printing and dyeing wastewater enters through a first liquid inlet pipe of the first tank body, and is discharged through a first liquid outlet pipe of the first tank body; a first carbon tube filling layer, the first carbon tube filling layer being arranged in the first tank body, and the first carbon tube filling layer being used for absorbing organic pollutants in the printing and dyeing wastewater; A first titanium dioxide photocatalyst, wherein the first titanium dioxide photocatalyst is disposed on a portion of the first carbon tube filling layer, and the first titanium dioxide photocatalyst is used for oxidatively decomposing organic pollutants in the printing and dyeing wastewater; a first doser, the first doser being used to add hydrogen peroxide and EDTA-Fa into the first tank, the hydrogen peroxide being used to oxidatively decompose organic pollutants in the printing and dyeing wastewater, and the EDTA-Fa being mixed with the hydrogen peroxide to oxidatively decompose organic pollutants in the printing and dyeing wastewater; a first ultraviolet light source, which is used to emit ultraviolet light and irradiate the hydrogen peroxide and the EDTA-Fa on the first titanium dioxide photocatalyst and the first carbon tube filling layer respectively; a second tank body, the printing and dyeing wastewater enters the second tank body through a second liquid inlet pipe of the second tank body, and the printing and dyeing wastewater is discharged through a second liquid outlet pipe of the second tank body; a second carbon tube filling layer, the second carbon tube filling layer being arranged in the second tank body, and the second carbon tube filling layer being used for absorbing the printing and dyeing wastewater; A second titanium dioxide photocatalyst, wherein the second titanium dioxide photocatalyst is disposed on a portion of the second carbon tube filling layer, and the second titanium dioxide photocatalyst is used to decompose organic pollutants in the printing and dyeing wastewater; A second doser, the second doser is used to add hydrogen peroxide and EDTA-Fa into the second tank, the hydrogen peroxide is used to oxidize and decompose organic pollutants in the printing and dyeing wastewater, and the EDTA-Fa is mixed with the hydrogen peroxide to oxidize and decompose organic pollutants in the printing and dyeing wastewater; a second ultraviolet light source, the second ultraviolet light source being used to emit ultraviolet light and irradiate the hydrogen peroxide and the EDTA-Fa on the second titanium dioxide photocatalyst and the second carbon tube filling layer respectively; A first COD detector, the first COD detector is used to detect a first COD value of the printing and dyeing wastewater discharged from the first liquid outlet pipe; as well as External circulation pump; The printing and dyeing wastewater in the first tank is mixed with the first carbon tube filling layer, the first titanium dioxide photocatalyst, hydrogen peroxide and EDTA-Fa respectively, and the printing and dyeing wastewater in the second tank is mixed with the second carbon tube filling layer, the second titanium dioxide photocatalyst, hydrogen peroxide and EDTA-Fa respectively. Among them, when the first COD value is greater than the standard COD value, the printing and dyeing wastewater discharged from the first liquid outlet pipe flows back into the second liquid inlet pipe through the external circulation pump, and the first doser controls the concentration of EDTA-Fa in the first tank body to 2-4 mol / L, so that the first carbon tube filling layer is regenerated.

2. A photocatalytic treatment device for printing and dyeing wastewater as claimed in claim 1, characterized in that: A second COD detector is provided on the second liquid outlet pipe, and the second COD detector is used to detect the second COD value of the printing and dyeing wastewater discharged through the second liquid outlet pipe. When the second COD value is greater than the standard COD value, the second doser controls the concentration of EDTA-Fa in the second tank body to be 2-4 mol / L, and the printing and dyeing wastewater discharged from the second liquid outlet pipe flows back into the first liquid inlet pipe through the external circulation pump, so that the second carbon tube filling layer is regenerated.

3. A photocatalytic treatment device for printing and dyeing wastewater as claimed in claim 2, characterized in that: When the first COD value and the second COD value are both lower than the standard COD value, the printing and dyeing wastewater enters the first tank body through the first liquid inlet pipe of the first tank body, and is discharged through the first liquid outlet pipe of the first tank body, and the second tank body is in a standby state.

4. A photocatalytic treatment device for printing and dyeing wastewater as claimed in claim 2, characterized in that: The first liquid outlet pipe and the second liquid outlet pipe are both connected to an intermediate pool, and the intermediate pool is connected to the external circulation pump. When the first COD value is greater than the standard value, the printing and dyeing wastewater in the intermediate pool flows back to the second liquid inlet pipe through the external circulation pump. When the second COD value is greater than the standard value, the printing and dyeing wastewater in the intermediate pool flows back to the first liquid inlet pipe through the external circulation pump.

5. A photocatalytic treatment device for printing and dyeing wastewater as claimed in claim 4, characterized in that: When the wastewater treatment device is under maintenance, the printing and dyeing wastewater is discharged into the intermediate pool.

6. A photocatalytic treatment device for printing and dyeing wastewater as claimed in claim 1, 2, 3, 4 or 5, characterized in that: A first circulation pump is arranged in the first tank body, and the first circulation pump is arranged on the lower part of the first tank body. A plurality of first spray pipes are arranged on the first circulation pump, and an adapted first spray pipe is arranged on one side of each first carbon tube filling layer. The first spray pipe is used to spray the liquid sucked by the first circulation pump onto the first carbon tube filling layer and the surface of the first titanium dioxide photocatalyst respectively, so that the liquid flows through the surface of the first titanium dioxide photocatalyst and the surface of the first carbon tube filling layer in multiple cycles, and the liquid is a mixture of hydrogen peroxide and EDTA-Fa.

7. A photocatalytic treatment device for printing and dyeing wastewater as claimed in claim 6, characterized in that: A portion of the first spray pipe is arranged on the outer side of the first tank body, a liquid outlet pipe portion of the first spray pipe extends into the first tank body through the outer shell of the first tank body, a plurality of first nozzles are arranged at intervals on the liquid outlet pipe portion of the first spray pipe, the first nozzles are used to spray the liquid on the first carbon tube filling layer and the first titanium dioxide photocatalyst, and a liquid inlet pipe portion of the first spray pipe is arranged on the liquid outlet of the first circulation pump.

8. A photocatalytic treatment device for printing and dyeing wastewater as claimed in claim 1, 2, 3, 4 or 5, characterized in that: A second circulation pump is arranged in the second tank body, and the second circulation pump is arranged on the lower part of the second tank body. A plurality of second spray pipes are arranged on the second circulation pump, and an adapted second spray pipe is arranged on one side of each second carbon tube filling layer. The second spray pipe is used to spray the liquid sucked by the second circulation pump onto the second carbon tube filling layer and the surface of the second titanium dioxide photocatalyst respectively, so that the liquid flows through the surface of the second titanium dioxide photocatalyst and the surface of the second carbon tube filling layer in multiple cycles, and the liquid is a mixture of hydrogen peroxide and EDTA-Fa.

9. A photocatalytic treatment device for printing and dyeing wastewater as claimed in claim 8, characterized in that: A portion of the second spray pipe is arranged on the outer side of the second tank body, a liquid outlet pipe portion of the second spray pipe extends into the second tank body through the outer shell of the second tank body, a plurality of second nozzles are arranged at intervals on the liquid outlet pipe portion of the second spray pipe, the second nozzles are used to spray the liquid on the second carbon tube filling layer and the second titanium dioxide photocatalyst, and a liquid inlet pipe portion of the second spray pipe is arranged on the liquid outlet of the second circulation pump.

10. A photocatalytic treatment device for printing and dyeing wastewater according to claim 1, 2, 3, 4 or 5, characterized in that: When the first COD value is less than the standard COD value, the first doser controls the EDTA-Fa concentration in the first tank to be 0-2 mol / L, and the printing and dyeing wastewater discharged from the second liquid outlet pipe flows back into the first liquid inlet pipe through the external circulation pump, so that the second carbon tube filling layer is regenerated.

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