System and method for removing new pollutants through MBR coupling advanced oxidation

Abstract

The invention provides a system and method for removing new pollutants through MBR coupling advanced oxidation, and belongs to the technical field of sewage treatment.The main process comprises an MBR process unit and an advanced oxidation process unit, the advanced oxidation process comprises an ozone micro-nano bubble device, a corresponding intelligent ozone adding control module, an ultraviolet light catalysis advanced oxidation device and a corresponding intelligent hydrogen peroxide adding control module. The background value of pollutants in water is fully reduced and a part of new pollutants are removed through the MBR process unit; part of light absorption substances and part of new pollutants are removed through the ozone micro-nano bubble device, and the light transmittance of the water body is increased to 82% or above; finally, hydroxyl free radicals (. OH) with strong oxidizing property are generated through UV / H2O2 excitation, and most of new pollutants are removed. The two process units are deeply coupled, the working procedures are closely linked, and new pollutants can be efficiently removed; the two intelligent control modules are used for accurately adding chemicals according to the treatment effect, so that the operation cost can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a system and method for removing new pollutants by MBR coupling advanced oxidation. Background Art

[0002] For water pollution, traditional sewage biochemical treatment processes can effectively remove conventional pollutants such as nutrients and organic matter in water, but there is uncertainty in the removal rate of new pollutants, so advanced oxidation technology is usually required to remove new pollutants. Advanced oxidation technology is a method based on the strong oxidation decomposition of pollutants by hydroxyl radicals (·OH). It can remove new pollutants by exciting oxidants such as O3 and H2O2 with ultraviolet light to produce ·OH. However, when treating new pollutants, advanced oxidation technology still has problems such as low oxidant utilization, high cost, and unstable water quality, making it difficult to promote on a large scale. Summary of the invention

[0003] The object of the present invention is to provide a system and method for removing new pollutants by coupling MBR with advanced oxidation, so as to solve at least one technical problem existing in the above-mentioned background technology.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] The present invention provides a system for removing new pollutants by coupling MBR with advanced oxidation, comprising an anaerobic tank, a front anoxic tank, an aerobic tank, a rear anoxic tank, a biochemical system of a membrane tank, an ozone micro-nano bubble device, an ultraviolet catalytic advanced oxidation device and an intelligent dosing control module, wherein the intelligent dosing control module comprises an ozone intelligent dosing control module and a hydrogen peroxide intelligent dosing control module; the ozone micro-nano bubble device is connected to the ozone intelligent dosing control module, and the UV 254 The detection points are set at the water inlet and outlet of the ozone micro-nano bubble device; the ultraviolet catalytic advanced oxidation device is connected to the hydrogen peroxide intelligent dosing control module, and the ORP detection points are set at the water inlet and outlet of the ultraviolet catalytic advanced oxidation device; the intelligent dosing control modules are integrated in the control cabinet, and the monitoring data signals are collected and transmitted to the control cabinet in real time, wherein the ozone intelligent dosing control module is connected to the water inlet and outlet UV 254 The value and changes of ORP control the ozone dosage, and the ultraviolet photocatalytic advanced oxidation device controls the hydrogen peroxide dosage through the ORP value and changes of its inlet and outlet water, thereby achieving stable removal of new pollutants and reducing operating costs.

[0006] Furthermore, the control cabinet is connected to an environmental parameter monitoring and acquisition module, including a feedforward control instrument group and a feedback control instrument group; the feedforward control instrument group is used to monitor water inlet flow data, ozone concentration data, ozone flow data, hydrogen peroxide flow data, ozone micro-nano bubble device water inlet UV254 data, ORP data of water inlet of UV-catalytic advanced oxidation device; the feedback control instrument group is used to monitor the UV outflow of ozone micro-nano bubble device 254 Data, ORP data of water outlet from ultraviolet photocatalytic advanced oxidation device.

[0007] Furthermore, the water flow data, ozone concentration data, ozone flow data, hydrogen peroxide flow data, ozone micro-nano bubble device water UV 254 Numerical value, ozone micro-nano bubble device water UV 254 The numerical value, the UV-catalytic advanced oxidation device inlet ORP value, and the UV-catalytic advanced oxidation device outlet ORP value are sent to the control cabinet, and real-time calculation is performed in the control cabinet to achieve a lower dosage of the agent while ensuring the water quality.

[0008] Furthermore, the sewage is pre-treated and separated by the MBR membrane through the biochemical system of anaerobic tank-front anoxic tank-aerobic tank-post anoxic tank-membrane tank, achieving stable effluent UV 254 ≤0.12, turbidity ≤0.15NTU.

[0009] Furthermore, ozone micro-nano bubbles are introduced into the water UV 254 The value is passed to the ozone intelligent dosing control module, and the model calculates and adjusts the ozone dosage in real time to maintain the ozone dosage and UV 254 The proportion of reduction is in the high efficiency range, and the UV of the water outlet of the micro-nano bubble device is controlled 254 In the set value.

[0010] Furthermore, for the MBR effluent, the ozone dosage was increased from 0 to 1-2 mg / L as a step, and 4-5 groups of UV of the effluent from the ozone micro-nano bubble device under different dosages were obtained. 254 The value is calculated as follows:

[0011]

[0012] O 3,limit =|UV i / b0|

[0013] Wherein, O3 represents the amount of ozone added, mg / L; Indicates the average ozone dosage, mg / L; UV o Indicates water UV 254 Value, cm -1 ; Indicates water UV 254 Mean, cm -1 ; b0 represents the initial unit ozone reduction UV 254 Value, cm -1 / (mg / L); R2 represents the correlation coefficient of the fitted straight line; 3,limit Indicates the upper limit of ozone dosage for ozone micro-nano bubble device, mg / L; UV i Indicates the current water UV of the ozone micro-nano bubble device 254 When R 2 ≥0.8, the current value is taken as b0 value, when R 2 When <0.8, remove the point with the maximum deviation and recalculate the b0 value;

[0014] The initial dosage is calculated as follows:

[0015] O 3,0 =(UV S -UV i ) / b,UV i >UV S

[0016] O 3,0 =0,UV i ≤UV S

[0017] Among them, O 3,0 Indicates the initial ozone dosage, mg / L; UV S Indicates the water outlet setting value of the ozone micro-nano bubble device.

[0018] Furthermore, the calculation method of ozone dosage during operation is as follows:

[0019] O 3,T+1 =O 3,T +ΔO 3，T+1 , [0, O 3,limit ]

[0020] ΔO 3,T+1 =((UV S -UV O,T )+(UV i，T+1 -UV i，T )) / b0

[0021] Wherein, the self-control adjustment period T = hydraulic retention time (HRT) of the ozone micro-nano bubble device; 3,T Indicates the ozone dosage setting value of the current cycle, mg / L; O 3,T+1 Indicates the ozone dosage setting value for the next cycle, mg / L, and so on; ΔO 3,T+1 Indicates the change in ozone dosage in the next cycle, mg / L, and so on; UV O,T Indicates the UV output of the ozone micro-nano bubble device in the current cycle 254 Value, cm -1 ; UV i，TIndicates the water UV of the ozone micro-nano bubble device in the current cycle 254 Value, cm -1 ; UV i，T+1 Indicates the water UV of the ozone micro-nano bubble device in the next cycle 254 Value, cm -1 , and so on;

[0022] If ΔO3>0 twice in a row, calculate If b T >b T-1 >0.8×b0, then ΔO 3，T+1 =0;

[0023] Wherein, ΔO3 represents the change in ozone dosage per cycle, mg / L; b T Indicates the UV reduction per unit ozone dosage in the current cycle 254 Value, cm -1 / (mg / L); b T-1 Indicates the UV reduction per unit ozone dosage in the previous week 254 Value, cm -1 / (mg / L), and so on; UV O，T-1 Indicates the UV of the water outlet of the ozone micro-nano bubble device in the previous cycle 254 Value, cm- 1 , and so on;

[0024] If ΔO3≠0, calculate b T , take the average of the first 5 times like Then b0=b T .

[0025] Furthermore, the current ozone dosage and the ORP value of the water inlet of the ultraviolet photocatalytic advanced oxidation device are transmitted to the hydrogen peroxide intelligent dosage control module. The model calculates and adjusts the hydrogen peroxide dosage in real time, maintains the ratio of hydrogen peroxide dosage to O3 reduction in the high-efficiency range, and controls the water outlet ORP of the ultraviolet photocatalytic advanced oxidation device ≤250mV.

[0026] Furthermore, for the effluent of the ozone micro-nano bubble device, the dosage of hydrogen peroxide was increased from 0 to 1-2 mg / L as a step, and the ORP values ​​of the effluent of the ultraviolet photocatalytic advanced oxidation device under 4-5 different dosages were obtained, which were calculated as follows:

[0027]

[0028] H2O 2,limit =O 3,limit

[0029] Wherein, H2O2 represents the dosage of hydrogen peroxide, mg / L; Indicates the average amount of hydrogen peroxide added, mg / L; ORP o Indicates the outlet water ORP value, mV; represents the average ORP value of the effluent, mV; k0 represents the value of the initial unit of hydrogen peroxide to reduce the ORP, mV / (mg / L); R 2 Represents the correlation coefficient of the fitting line; H2O 2,limit Indicates the upper limit of hydrogen peroxide dosage;

[0030] The calculation method of initial dosage is as follows:

[0031] H2O 2,0 =(ORP s -ORP i ) / k0,ORP i >ORP s

[0032] H2O 2,0 =0,ORP i ≤ORP s

[0033] Among them, H2O 2,0 Indicates the initial hydrogen peroxide dosage, mg / L; ORP s Indicates the outlet water setting value of the UV photocatalytic advanced oxidation device, 250mV; ORP i Indicates the ORP value of the water inlet to the UV photocatalytic advanced oxidation device, mV.

[0034] Furthermore, the calculation method for the amount of ozone hydrogen peroxide added during the operation process is as follows:

[0035] H2O 2，t+1 =H2O 2,t +ΔH2O 2,t+1 ,[0,H2O 2,limit ]

[0036] ΔH2O 2，t+1 =((ORP s -ORP O，t )+(ORP i，t+1 -ORP i,t )) / k0

[0037] Among them, the automatic adjustment cycle t = the hydraulic retention time of the ultraviolet photocatalytic advanced oxidation device; H2O 2，t Indicates the amount of hydrogen peroxide added in the current cycle, mg / L; H2O 2，t+1 Indicates the setting value of hydrogen peroxide dosage in the next cycle, mg / L, and so on; ΔH2O 2，t+1 Indicates the change in the amount of hydrogen peroxide added in the next cycle, mg / L, and so on; ORP O，tIndicates the outlet ORP value of the UV-catalytic advanced oxidation device in the current cycle, mV; ORP i,t Indicates the ORP value of the water inlet of the UV-catalytic advanced oxidation device in the current cycle, mV; ORP i,t+1 It indicates the ORP value of the water inlet of the UV-catalytic advanced oxidation device in the next cycle, mV, and so on;

[0038] If ΔH2O2>0 twice in a row, calculate If k t >k t-1 >0.8×k0, then ΔH2O 2，t+1 =0;

[0039] Where ΔH2O2 represents the change in the amount of hydrogen peroxide added per cycle, mg / L; k t Indicates the ORP value of the unit hydrogen peroxide dosage reduction in the current cycle, mV / (mg / L); ORP O，t-1 Indicates the ORP value of the effluent from the UV-catalytic advanced oxidation device in the previous cycle, and so on; ORP i,t-1 It indicates the ORP value of the water inlet of the UV-catalytic advanced oxidation device in the previous cycle, and so on;

[0040] If ΔH2O2≠0, calculate k t , take the average of the first 5 times like but

[0041] The invention has the following beneficial effects: the MBR technology is used to provide favorable water quality conditions for advanced oxidation to remove new pollutants: low turbidity, low and stable organic matter content; the ozone micro-nano bubble technology is used to provide favorable water quality conditions for ultraviolet light catalytic advanced oxidation: high light transmittance, low light-absorbing organic matter content; low-pressure ultraviolet light advanced oxidation technology is used to directly degrade a part of new pollutants using ultraviolet light, and at the same time, based on the high light absorption of O3 at 254nm wavelength and the dual effects of hydrogen peroxide, ·OH generation is stimulated, the process is deeply coupled, the connection is tight, and new pollutants are removed efficiently. The ozone micro-nano bubble aeration device is equipped with an ozone intelligent dosing control module, which is controlled by UV light. 254 The numerical value and change value of ORP are used to intelligently control the O3 dosage in a cost-effective range. The ultraviolet photocatalytic advanced oxidation device is equipped with a hydrogen peroxide intelligent dosing control module. Through the numerical value and change value of ORP, the hydrogen peroxide dosage is intelligently controlled to match the O3 dosage, thereby reducing the pollutant treatment cost.

[0042] Additional advantages of the present invention will be more clearly presented in the following description or learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0044] Figure 1 This is a schematic diagram of the system structure of MBR coupled with advanced oxidation to remove new pollutants according to an embodiment of the present invention.

[0045] Figure 2 The ozone reaction unit ORP and UV 254 Schematic diagram of changes in ozone concentration.

[0046] Figure 3 The ultraviolet catalytic reaction unit ORP and UV 254 Schematic diagram of the change in hydrogen peroxide dosage concentration.

[0047] Figure 4 This is a graph showing the variation of sulfadiazine removal efficiency over time as described in an embodiment of the present invention.

[0048] Figure 5 UV water production under different ozone dosages described in the embodiments of the present invention 254 , schematic diagram of ORP changes.

[0049] Figure 6 UV water production under different hydrogen peroxide dosages described in the embodiments of the present invention 254 , schematic diagram of ORP changes. DETAILED DESCRIPTION

[0050] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below by the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0051] It should be understood by those skilled in the art that unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this invention belongs.

[0052] It should also be understood that terms, such as those defined in commonly used dictionaries, should be understood to have a meaning consistent with that in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless as defined herein.

[0053] Those skilled in the art will appreciate that, unless otherwise stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements and / or groups thereof.

[0054] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. Different embodiments or examples described in this specification and features of different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

[0055] To facilitate understanding of the present invention, the present invention is further explained below with reference to specific embodiments in conjunction with the accompanying drawings, and the specific embodiments do not constitute a limitation on the embodiments of the present invention.

[0056] Those skilled in the art should understand that the drawings are merely schematic diagrams of embodiments, and the components in the drawings are not necessarily necessary for implementing the present invention.

[0057] The present invention provides a system and method for removing new pollutants by coupling an MBR (membrane bioreactor) with advanced oxidation. Sewage sequentially enters a biochemical system (MBR process unit) provided with an anaerobic tank, an anoxic tank, an aerobic tank, a post-anoxic tank, and a membrane tank, an ozone micro-nano bubble aeration device, and an ultraviolet photocatalytic advanced oxidation device. The dosage of ozone and hydrogen peroxide is adjusted in real time through an intelligent dosing control module, thereby solving at least one technical problem existing in the above-mentioned background technology.

[0058] The present invention is realized by the following technical scheme: a system for removing new pollutants by coupling MBR with advanced oxidation, in which municipal sewage enters the MBR process unit, and conventional pollutants and a part of new pollutants are removed through high sludge concentration and membrane filtration separation, and the turbidity and organic matter content of the effluent are greatly reduced; the effluent of MBR enters the ozone micro-nano bubble aeration device to remove UV 254Increase the light transmittance to more than 82%, reduce the waste of interfering substances absorbing ultraviolet light, and remove some new pollutants at the same time; the effluent from the ozone micro-nano bubble aeration device enters the ultraviolet light catalytic advanced oxidation device, which uses ultraviolet light to directly degrade some new pollutants, and at the same time, a large amount of ·OH is jointly produced by O3 / UV / H2O2 to remove most of the new pollutants. Through the above technical solution, the sewage passes through the MBR process unit, reducing the substances that significantly affect the efficiency of removing new pollutants and the dosage of the advanced oxidation unit; after passing through the ozone micro-nano bubble aeration device, the ozone mass transfer efficiency and utilization rate are increased to more than 95% by using the efficient dissolution method of ozone, and UV is removed. 254 , reduce the content of interferences to strengthen the subsequent excitation effect of ultraviolet light on the oxidant; after the ultraviolet light catalytic advanced oxidation device, use ultraviolet light to directly degrade a part of the new pollutants, and at the same time, based on the high absorbance of O3 to 254nm wavelength and the dual effects of hydrogen peroxide, promote the chain reaction of OH generation to remove most of the new pollutants. Among them, the dosage of the agent is intelligently controlled to achieve efficient, low-consumption and stable removal of new pollutants. The ozone micro-nano bubble aeration device is equipped with an ozone intelligent dosing control module, including an inlet flowmeter, an ozone concentration meter, an ozone flowmeter, a flow regulating valve, and two UV inlet and outlet valves. 254 The online monitoring instrument is used to control the ozone dosage in real time. The ultraviolet photocatalytic advanced oxidation device is equipped with a hydrogen peroxide intelligent dosing control module, which includes a hydrogen peroxide flow meter, a flow regulating valve, an ultraviolet photocatalytic advanced oxidation device inlet ORP meter, and an ultraviolet photocatalytic advanced oxidation device outlet ORP meter, which is used to control the hydrogen peroxide dosage in real time.

[0059] Example 1

[0060] In this embodiment 1, a system and method for removing new pollutants by MBR coupling advanced oxidation is provided, including a biochemical system (MBR process unit) of an anaerobic tank-front anoxic tank-aerobic tank-rear anoxic tank-membrane tank arranged in sequence, an ozone micro-nano bubble device, an ultraviolet photocatalytic advanced oxidation device, and an intelligent dosing control module including an ozone intelligent dosing control module and a hydrogen peroxide intelligent dosing control module. The ultraviolet photocatalytic advanced oxidation device uses a 254nm low-pressure ultraviolet lamp. The ozone micro-nano bubble device is connected to the ozone intelligent dosing control module, UV 254 The detection points are set at the water inlet and outlet of the ozone micro-nano bubble device; the ultraviolet catalytic advanced oxidation device is connected to the hydrogen peroxide intelligent dosing control module, and the ORP detection points are set at the water inlet and outlet of the ultraviolet catalytic advanced oxidation device; the intelligent dosing control modules are integrated in the control cabinet, and the monitoring data signals are collected and transmitted to the control cabinet in real time, wherein the ozone intelligent dosing control module is connected to the water inlet and outlet UV 254The value and changes of ORP control the ozone dosage, and the ultraviolet photocatalytic advanced oxidation device controls the hydrogen peroxide dosage through the ORP value and changes of its inlet and outlet water, thereby achieving stable removal of new pollutants and reducing operating costs.

[0061] The control cabinet is connected to the environmental parameter monitoring and acquisition module, including a feedforward control instrument group and a feedback control instrument group; the feedforward control instrument group is used to monitor water flow data, ozone concentration data, ozone flow data, hydrogen peroxide flow data, ozone micro-nano bubble device water UV 254 data, ORP data of water inlet of UV-catalytic advanced oxidation device; the feedback control instrument group is used to monitor the UV outflow of ozone micro-nano bubble device 254 Data, UV catalytic advanced oxidation device outlet ORP data. Inlet flow data, ozone concentration data, ozone flow data, hydrogen peroxide flow data, ozone micro-nano bubble device inlet UV 254 Numerical value, ozone micro-nano bubble device water UV 254 The numerical value, the UV-catalytic advanced oxidation device inlet ORP value, and the UV-catalytic advanced oxidation device outlet ORP value are sent to the control cabinet, and real-time calculation is performed in the control cabinet to achieve a lower dosage of the agent while ensuring the water quality.

[0062] The urban sewage is pre-treated and the biochemical system of anaerobic tank-front anoxic tank-aerobic tank-post anoxic tank-membrane tank (MBR process unit) is precisely separated by MBR membrane to achieve stable effluent UV 254 ≤0.12, turbidity ≤0.15NTU. Put ozone micro-nano bubbles into the water UV 254 The value is passed to the ozone intelligent dosing control module, and the model calculates and adjusts the ozone dosage in real time to maintain the ozone dosage and UV 254 The proportion of reduction is in the high efficiency range, and the UV of the water outlet of the micro-nano bubble device is controlled 254 Near the set value.

[0063] The specific process is to increase the ozone dosage from 0 to 1-2 mg / L for the effluent of the MBR of a specific water plant, and obtain 4-5 groups of UV of the effluent of the ozone micro-nano bubble device under different dosages. 254 The value is calculated as follows:

[0064]

[0065] O 3，limit =|UV i / b0|

[0066] Wherein, O3 represents the amount of ozone added, mg / L; Indicates the average ozone dosage, mg / L; UV o Indicates water UV254 Value, cm -1 ; Indicates water UV 254 Mean, cm -1 ; b0 represents the initial unit ozone reduction UV 254 Value, cm -1 / (mg / L); R 2 represents the correlation coefficient of the fitted straight line; 3,limit Indicates the upper limit of ozone dosage for ozone micro-nano bubble device, mg / L; UV i Indicates the current water UV of the ozone micro-nano bubble device 254 When R 2 >0.8, the current value is taken as b0 value, when R 2 When <0.8, remove the point with the maximum deviation and recalculate the b0 value.

[0067] The initial dosage is calculated as follows:

[0068] O 3,0 =(UV S -UV i ) / b,UV i >UV S

[0069] O 3,0 =0,UV i ≤UV S

[0070] Among them, O 3,0 Indicates the initial ozone dosage, mg / L; UV S Indicates the water outlet setting value of the ozone micro-nano bubble device, which is set to 0.08 cm in this embodiment -1 .

[0071] The calculation method of ozone dosage during operation is as follows:

[0072] O 3，T+1 =O 3，T +ΔO 3，T+1 , [0, O 3,limit ]

[0073] ΔO 3，T+1 =((UV S -UV O,T )+(UV i，T+1 -UV i，T )) / b0

[0074] Wherein, the self-control adjustment period T = hydraulic retention time (HRT) of the ozone micro-nano bubble device; s，T Indicates the ozone dosage setting value of the current cycle, mg / L; O3,T+1 Indicates the ozone dosage setting value for the next cycle, mg / L, and so on; ΔO 3,T+1 Indicates the change in ozone dosage in the next cycle, mg / L, and so on; UV O，T Indicates the UV254 value of the water outlet of the ozone micro-nano bubble device in the current cycle, cm -1 ; UV i，T Indicates the water UV of the ozone micro-nano bubble device in the current cycle 254 Value, cm -1 ; UV i，T+1 Indicates the water UV of the ozone micro-nano bubble device in the next cycle 254 Value, cm -1 , and so on.

[0075] If ΔO3>0 twice in a row, calculate If b T >b T-1 >0.8×b0, then ΔO 3,T+1 =0.

[0076] Wherein, ΔO3 represents the change in ozone dosage per cycle, mg / L; b T Indicates the UV reduction per unit ozone dosage in the current cycle 254 Value, cm -1 / (mg / L); b T-1 Indicates the UV reduction per unit ozone dosage in the previous week 254 Value, cm -1 / (mg / L), and so on; UV O,T-1 Indicates the UV of the water outlet of the ozone micro-nano bubble device in the previous cycle 254 Value, cm -1 , and so on.

[0077] If ΔO3≠0, calculate b T , take the average of the first 5 times like Then b0=b T .

[0078] The current ozone dosage and the ORP value of the water inlet of the ultraviolet photocatalytic advanced oxidation device are passed to the hydrogen peroxide intelligent dosing control module. The model calculates and adjusts the hydrogen peroxide dosage in real time to maintain the ratio of hydrogen peroxide dosage to O3 reduction in the high-efficiency range, and controls the water outlet ORP of the ultraviolet photocatalytic advanced oxidation device ≤250mV.

[0079] The specific process is to increase the dosage of hydrogen peroxide from 0 to 1-2 mg / L for the effluent of the ozone micro-nano bubble device, and obtain 4-5 groups of ORP values ​​of the effluent of the ultraviolet photocatalytic advanced oxidation device under different dosages, and calculate as follows:

[0080]

[0081] H2O 2,limit =O 3,limit

[0082] Wherein, H2O2 represents the dosage of hydrogen peroxide, mg / L; Indicates the average amount of hydrogen peroxide added, mg / L; ORP o Indicates the outlet water ORP value, mV; represents the average ORP value of the effluent, mV; k0 represents the value of the initial unit of hydrogen peroxide to reduce the ORP, mV / (mg / L); R 2 Represents the correlation coefficient of the fitting straight line; H2O 2,limit Indicates the upper limit of hydrogen peroxide dosage.

[0083] The initial dosage is calculated as follows:

[0084] H2O 2,0 =(ORP s -ORP i ) / k0,ORP i >ORP s

[0085] H2O 2,0 =0,ORP i ≤ORP s

[0086] Among them, H2O 2,0 Indicates the initial hydrogen peroxide dosage, mg / L; ORP s Indicates the outlet water setting value of the UV photocatalytic advanced oxidation device, 250mV; ORP i Indicates the ORP value of the water inlet to the UV photocatalytic advanced oxidation device, mV.

[0087] The calculation method for the amount of ozone hydrogen peroxide added during operation is as follows:

[0088] H2O 2,t+1 =H2O 2,t +ΔH2O 2,t+1 ,[0,H2O 2,limit ]

[0089] ΔH2O 2，t+1 =((ORP s -ORP O，t )+(ORP i，t+1 -ORP i，t )) / k0

[0090] Among them, the self-control adjustment period t = the hydraulic retention time (HRT) of the ultraviolet photocatalytic advanced oxidation device; H2O 2，t Indicates the amount of hydrogen peroxide added in the current cycle, mg / L; H2O 2，t+1 Indicates the setting value of hydrogen peroxide dosage in the next cycle, mg / L, and so on; ΔH2O 2，t+1 Indicates the change in the amount of hydrogen peroxide added in the next cycle, mg / L, and so on; ORP O，t Indicates the outlet ORP value of the UV-catalytic advanced oxidation device in the current cycle, mV; ORP i，t Indicates the ORP value of the water inlet of the UV-catalytic advanced oxidation device in the current cycle, mV; ORP i，t+1 Indicates the ORP value of the water inlet of the UV-catalytic advanced oxidation device in the next cycle, mV, and so on. If ΔH2O2>0 twice in a row, calculate If k t >k t-1 >0.8×k0, then ΔH2O 2，t+1 =0.

[0091] Wherein, ΔH2O2 represents the change in the amount of hydrogen peroxide added per cycle, mg / L; k t Indicates the ORP value of the unit hydrogen peroxide dosage reduction in the current cycle, mV / (mg / L); ORP O，t-1 Indicates the ORP value of the effluent from the UV-catalytic advanced oxidation device in the previous cycle, and so on; ORP i,t-1 It indicates the ORP value of the water inlet of the ultraviolet photocatalytic advanced oxidation device in the previous cycle, and so on.

[0092] If ΔH2O2≠0, calculate k t , take the average of the first 5 times like but

[0093] The MBR process unit can biodegrade most nutrients and some new pollutants by using high sludge concentration, which can fully reduce the background value of pollutants in the water for the subsequent advanced oxidation process unit; in the advanced oxidation process unit, O3 can oxidize new pollutants containing double bonds or benzene rings, and the 254nm wavelength of ultraviolet light can directly degrade some new pollutants, and can generate strong oxidizing ·OH with O3, H2O2, etc., and degrade new pollutants indiscriminately. The mechanisms of UV / O3, UV / H2O2, and O3 / H2O2 to produce ·OH are as follows:

[0094] UV / O3

[0095] O3+hv→O( 1 D)+O2

[0096] O(1 D) +H2O→2·OH

[0097] UV / H2O2

[0098] H2O2+hv→2·OH

[0099] O3 / H2O2

[0100]

[0101] like Figure 1 As shown, in this embodiment, a system and method for removing new pollutants by MBR coupling advanced oxidation are provided. The sewage sequentially enters a biochemical system (MBR process unit) equipped with an anaerobic tank-anoxic tank-aerobic tank-post-anoxic tank-membrane tank, an ozone micro-nano bubble aeration device, and an ultraviolet photocatalytic advanced oxidation device, and the dosage of ozone and hydrogen peroxide is adjusted in real time through an intelligent dosing control module. The MBR process unit removes conventional pollutants and a portion of new pollutants through high sludge concentration and membrane filtration separation, and greatly reduces the turbidity and organic matter content of the effluent; the ozone micro-nano bubble aeration device is located after the MBR process unit, and the MBR effluent enters the ozone micro-nano bubble aeration device to remove UV 254 The light transmittance is increased to more than 82%, the absorption waste of ultraviolet light by interfering substances is reduced, and a part of new pollutants are removed at the same time; the ultraviolet catalytic advanced oxidation device is located after the ozone micro-nano bubble aeration device, and uses ultraviolet light to directly degrade a part of new pollutants, and at the same time, a large amount of ·OH is jointly produced by O3 / UV / H2O2 to remove most of the new pollutants.

[0102] Furthermore, the ozone micro-nano bubble aeration device is equipped with an ozone intelligent dosing control module, which includes a water inlet flow meter, an ozone concentration meter, an ozone flow meter, a flow regulating valve, two UV 254 Online monitoring instrument, the signal is used to calculate the ozone dosage in real time for regulation.

[0103] Furthermore, the ultraviolet photocatalytic advanced oxidation device is equipped with a hydrogen peroxide intelligent dosing control module, which includes a hydrogen peroxide flowmeter, a flow regulating valve, an ultraviolet photocatalytic advanced oxidation device inlet ORP meter, and an ultraviolet photocatalytic advanced oxidation device outlet ORP meter. The signal is used to calculate the hydrogen peroxide dosage in real time for regulation.

[0104] When treating actual sewage, the COD, TN and TP in the influent are 120-300 mg / L, 20-50 mg / L and 1.5-5 mg / L respectively. The MLSS of the biochemical pool of the MBR process unit is controlled at 8-10 g / L, and the total HRT is 16-18h. After the MBR reaction, the effluent UV 254≤0.12, most of the conventional pollutants are removed, and then the MBR effluent enters the ozone micro-nano bubble aeration device, and the ozone intelligent dosing module controls the ozone dosing concentration at 6-8mg / L, and the effluent UV 254 Stable below 0.07cm -1 The effluent from the ozone micro-nano bubble aeration device enters the ultraviolet catalytic oxidation device, and the hydrogen peroxide dosage is controlled by the hydrogen peroxide intelligent dosing module at about 6 mg / L, which can stably ensure the total process effluent UV 254 Less than 0.03cm -1 , ORP is lower than 250mV.

[0105] The system and method for removing new pollutants by MBR coupled with advanced oxidation described in this embodiment can achieve effective removal of new pollutants. The system includes an ozone intelligent dosing control module and a hydrogen peroxide intelligent dosing control module. The intelligent dosing module can control ozone and hydrogen peroxide to be added in a cost-effective dosing area, which is conducive to reducing the cost of pollutant treatment. At the same time, the MBR process unit and the advanced oxidation process unit are deeply coupled and closely connected, and new pollutants are efficiently removed.

[0106] The experimental results show that b0 = -0.068, R 2 =0.99, k0=-69.50, R 2 =0.99, initial water inlet UV 254 =0.117, calculated as O 3,limit =17mg / L, initial O 3,0 =5.4mg / L, calculated H2O 2,limit =5.4mg / L, follow the procedure, the effect is as follows Figures 2 to 6 shown.

[0107] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative work on the basis of the technical solution disclosed in the present invention should be included in the scope of protection of the present invention.

Claims

1. A system for removing new pollutants by coupling MBR with advanced oxidation, characterized in that: The invention comprises an anaerobic tank, a front anoxic tank, an aerobic tank, a rear anoxic tank, a biochemical system of a membrane tank, an ozone micro-nano bubble device, an ultraviolet catalytic advanced oxidation device and an intelligent dosing control module which are arranged in sequence; the intelligent dosing control module comprises an ozone intelligent dosing control module and a hydrogen peroxide intelligent dosing control module; the ozone micro-nano bubble device is connected to the ozone intelligent dosing control module, and the UV 254 The detection points are set at the water inlet and outlet of the ozone micro-nano bubble device; The ultraviolet catalytic advanced oxidation device is connected to the hydrogen peroxide intelligent dosing control module, and the ORP detection points are set at the water inlet and outlet of the ultraviolet catalytic advanced oxidation device; the intelligent dosing control modules are integrated in the control cabinet, and the monitoring data signals are collected and transmitted to the control cabinet in real time, wherein the ozone intelligent dosing control module controls the water inlet and outlet UV 254 The value and changes of ORP control the ozone dosage, and the ultraviolet photocatalytic advanced oxidation device controls the hydrogen peroxide dosage through the ORP value and changes of its inlet and outlet water, thereby achieving stable removal of new pollutants and reducing operating costs.

2. The MBR coupled advanced oxidation system for removing new pollutants according to claim 1 is characterized in that: The control cabinet is connected to the environmental parameter monitoring and acquisition module, including a feedforward control instrument group and a feedback control instrument group; the feedforward control instrument group is used to monitor water flow data, ozone concentration data, ozone flow data, hydrogen peroxide flow data, ozone micro-nano bubble device water UV 254 Data, UV photocatalytic advanced oxidation device inlet ORP data; The feedback control instrument group is used to monitor the UV of the water outlet of the ozone micro-nano bubble device 254 Data, ORP data of water outlet from ultraviolet photocatalytic advanced oxidation device.

3. The MBR coupled advanced oxidation system for removing new pollutants according to claim 1 is characterized in that: The water flow data, ozone concentration data, ozone flow data, hydrogen peroxide flow data, ozone micro-nano bubble device water UV 254 Numerical value, ozone micro-nano bubble device water outlet UV 254 The numerical value, the UV-catalytic advanced oxidation device inlet ORP value, and the UV-catalytic advanced oxidation device outlet ORP value are sent to the control cabinet, and real-time calculation is performed in the control cabinet to achieve a lower dosage of the agent while ensuring the water quality.

4. The MBR coupled advanced oxidation system for removing new pollutants according to claim 1 is characterized in that: The sewage is pre-treated and separated by the MBR membrane through the biochemical system of anaerobic tank, front anoxic tank, aerobic tank, rear anoxic tank and membrane tank, achieving stable effluent UV 254 ≤0.12, turbidity ≤0.15NTU.

5. The MBR coupled advanced oxidation system for removing new pollutants according to claim 1 is characterized in that: Put ozone micro-nano bubbles into water UV 254 The value is passed to the ozone intelligent dosing control module, and the model calculates and adjusts the ozone dosage in real time to maintain the ozone dosage and UV 254 The proportion of reduction is in the high efficiency range, and the UV of the water outlet of the micro-nano bubble device is controlled 254 In the set value.

6. The MBR coupled advanced oxidation system for removing new pollutants according to claim 5 is characterized in that: For the MBR effluent, the ozone dosage was increased from 0 to 1-2 mg / L as a step to obtain 4-5 groups of UV of the effluent from the ozone micro-nano bubble device under different dosages. 254 The value is calculated as follows: O 3,limit =|UV i / b0| Wherein, O3 represents the amount of ozone added, mg / L; Indicates the average ozone dosage, mg / L; UV o Indicates water UV 254 Value, cm -1 ; Indicates water UV 254 Mean, cm -1 ; b0 represents the initial unit ozone reduction UV 254 Value, cm -1 / (mg / L); R 2 represents the correlation coefficient of the fitted straight line; 3,limit Indicates the upper limit of ozone dosage for ozone micro-nano bubble device, mg / L; UV i Indicates the current water UV of the ozone micro-nano bubble device 254 When R 2 ≥0.8, the current value is taken as b0 value, when R 2 When <0.8, remove the point with the maximum deviation and recalculate the b0 value; The initial dosage is calculated as follows: O 3,0 =(UV S -UV i ) / b,UV i >UV S O 3,0 =0,UV i ≤UV S Among them, O 3,0 Indicates the initial ozone dosage, mg / L; UV S Indicates the water outlet setting value of the ozone micro-nano bubble device.

7. The MBR coupled advanced oxidation system for removing new pollutants according to claim 6 is characterized in that: The calculation method of ozone dosage during operation is as follows: O 3,T+1 =O 3,T +ΔO 3,T+1 ,[0,O 3,limit ] ΔO 3,T+1 =((UV S -UV O,T )+(UV i,T+1 -UV i,T )) / b0 Wherein, the self-control adjustment period T = hydraulic retention time (HRT) of the ozone micro-nano bubble device; 3,T Indicates the ozone dosage setting value of the current cycle, mg / L; O 3,T+1 Indicates the ozone dosage setting value for the next cycle, mg / L, and so on; ΔO 3,T+1 Indicates the change in ozone dosage in the next cycle, mg / L, and so on; UV O,T Indicates the UV output of the ozone micro-nano bubble device in the current cycle 254 Value, cm -1 ; UV i,T Indicates the water UV of the ozone micro-nano bubble device in the current cycle 254 Value, cm -1 ; UV i,T+1 Indicates the water UV of the ozone micro-nano bubble device in the next cycle 254 Value, cm -1 , and so on; If ΔO3>0 twice in a row, calculate If b T >b T-1 >0.8×b0, then ΔO 3,T+1 =0; Wherein, ΔO3 represents the change in ozone dosage per cycle, mg / L; b T Indicates the UV reduction per unit ozone dosage in the current cycle 254 Value, cm -1 / (mg / L); b T-1 Indicates the UV reduction per unit ozone dosage in the previous week 254 Value, cm -1 / (mg / L), and so on; UV O,T-1 Indicates the UV of the water outlet of the ozone micro-nano bubble device in the previous cycle 254 Value, cm -1 , and so on; If ΔO3≠0, calculate b T , take the average of the first 5 times like Then b0=b T .

8. The MBR coupled advanced oxidation system for removing new pollutants according to claim 7 is characterized in that: The current ozone dosage and the ORP value of the water inlet of the ultraviolet photocatalytic advanced oxidation device are passed to the hydrogen peroxide intelligent dosing control module. The model calculates and adjusts the hydrogen peroxide dosage in real time to maintain the ratio of hydrogen peroxide dosage to O3 reduction in the high-efficiency range, and controls the water outlet ORP of the ultraviolet photocatalytic advanced oxidation device ≤250mV.

9. The MBR coupled advanced oxidation system for removing new pollutants according to claim 8, characterized in that: For the effluent of the ozone micro-nano bubble device, the dosage of hydrogen peroxide was increased from 0 to 1-2 mg / L as a step, and the ORP values ​​of the effluent of the ultraviolet photocatalytic advanced oxidation device under 4-5 different dosages were obtained. The calculation was as follows: H2O 2,limit =O 3,limit Wherein, H2O2 represents the dosage of hydrogen peroxide, mg / L; Indicates the average amount of hydrogen peroxide added, mg / L; ORP o Indicates the outlet water ORP value, mV; represents the average ORP value of the effluent, mV; k0 represents the value of the initial unit of hydrogen peroxide to reduce the ORP, mV / (mg / L); R 2 Represents the correlation coefficient of the fitting straight line; H2O 2,limit Indicates the upper limit of hydrogen peroxide dosage; The calculation method of initial dosage is as follows: H2O 2,0 =(ORP s -ORP i ) / k0,ORP i >ORP s H2O 2,0 =0,ORP i ≤ORP s Among them, H2O 2,0 Indicates the initial hydrogen peroxide dosage, mg / L; ORP s Indicates the outlet water setting value of the UV photocatalytic advanced oxidation device, 250mV; ORP i Indicates the ORP value of the water inlet to the UV photocatalytic advanced oxidation device, mV.

10. The MBR coupled advanced oxidation system for removing new pollutants according to claim 9, characterized in that: The calculation method for the amount of ozone hydrogen peroxide added during operation is as follows: H2O 2,t+1 =H2O 2,t +ΔH2O 2,t+1 ,[0,H2O 2,limit ] ΔH2O 2,t+1 =((ORP s -ORP O,t )+(ORP i,t+1 -ORP i,t )) / k0 Among them, the automatic adjustment cycle t = the hydraulic retention time of the ultraviolet photocatalytic advanced oxidation device; H2O 2,t Indicates the amount of hydrogen peroxide added in the current cycle, mg / L; H2O 2,t+1 Indicates the setting value of hydrogen peroxide dosage in the next cycle, mg / L, and so on; ΔH2O 2,t+1 Indicates the change in the amount of hydrogen peroxide added in the next cycle, mg / L, and so on; ORP O,t Indicates the outlet ORP value of the UV-catalytic advanced oxidation device in the current cycle, mV; ORP i,t Indicates the ORP value of the water inlet of the UV-catalytic advanced oxidation device in the current cycle, mV; ORP i,t+1 It indicates the ORP value of the water inlet of the UV-catalytic advanced oxidation device in the next cycle, mV, and so on; If ΔH2O2>0 twice in a row, calculate If k t >k t-1 >0.8×k0, then ΔH2O 2,t+1 =0; Where ΔH2O2 represents the change in the amount of hydrogen peroxide added per cycle, mg / L; k t Indicates the ORP value of the unit hydrogen peroxide dosage reduction in the current cycle, mV / (mg / L); ORP O,t-1 Indicates the ORP value of the effluent from the UV-catalytic advanced oxidation device in the previous cycle, and so on; ORP i,t-1 It indicates the ORP value of the water inlet of the UV-catalytic advanced oxidation device in the previous cycle, and so on; If ΔH2O2≠0, calculate k t , take the average of the first 5 times like but

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