System and method for removal of recalcitrant multi-characteristic water pollutants

Abstract

The application provides a removal system and method for refractory biodegradable multi-characteristic water pollutants, wherein the removal system comprises: a combined treatment unit; an acid adjusting component for pre-adjusting the pH of raw water in a storage and lifting unit to a first interval and adjusting the pH in a hydroxyl radical generating unit to a second interval; an active catalyst feeding component comprising a first catalyst feeding component connected to the hydroxyl radical generating unit, a second catalyst feeding component connected to a degassing and adsorption decoloring unit, and a third catalyst feeding device arranged in the hydroxyl radical generating unit respectively; an oxidant feeding component comprising a main oxidant feeding component and an auxiliary oxidant feeding component; an alkali adjusting component for adjusting the pH in the degassing and adsorption decoloring unit to a third interval; an adsorption complex feeding component comprising an adsorbent component and a multi-calcium component; and a coagulant feeding component. According to the removal system provided by the application, the removal efficiency of the characteristic pollutants in water can be improved.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, and in particular to a system and method for removing multi-characteristic water pollutants that are difficult to biodegrade. Background Technology

[0002] Characteristic pollutants refer to a representative portion of the pollutants emitted by a certain industry, which can reflect the pollution level of that industry. Generally, they can be understood as pollutants emitted in large quantities or in total emissions, such as organic and inorganic pollutants that are difficult to biodegrade to the limit in the pharmaceutical industry. Within the same industry, the water pollutants referred to can also be different due to differences in production processes and products, and the difficulty of degradation and treatment will also vary.

[0003] In the process of realizing this invention, the inventors discovered at least the following problems in the prior art:

[0004] Existing industrial wastewater, wastewater from special industries, and mixed industrial wastewater often contain a variety of organic pollutants (such as aromatic compounds and heterocyclic compounds). Current degradation technologies, such as conventional Fenton oxidation, Fenton-like oxidation, or ozone-aerated biological filters, typically achieve removal rates of less than 45% for persistent organic pollutants (CODnb) with long-chain functional groups that are difficult to biodegrade. This makes it difficult to ensure that the overall effluent meets or exceeds Class A discharge standards or reclaimed water standards. COD often exceeds 50 mg / L, color far exceeds 30 mg / L, and total phosphorus also exceeds 0.5 mg / L. These pollutants are difficult to effectively degrade through biochemical pathways, resulting in low removal efficiency. Consequently, the effluent contains high levels of dissolved COD, color, recalcitrant total phosphorus, and emerging water pollutants (such as POPs and PPCPs). Products contain high residual concentrations of multiple characteristic pollutants, including antibiotics, endocrine disruptors (EDCs), perfluorinated and polyfluoroalkyl substances (PFAS), and fluorides. These pollutant indicators in the effluent are difficult to consistently meet standards, making it difficult to guarantee the ultimate quality of the effluent and to meet the requirements for its resource reuse. Furthermore, the infrastructure investment is large, with high energy, material, and water consumption, as well as high periodic maintenance costs. The emissions of greenhouse gases, particularly carbon dioxide equivalents, are also significant, making it difficult to achieve a significant synergistic effect of environmental, economic, and social benefits.

[0005] Therefore, there is a need for a removal system and method for recalcitrant and biodegradable multi-characteristic water pollutants to at least partially solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides a system and method for removing multi-characteristic water pollutants that are difficult to biodegrade, which can enhance the removal efficiency of residual characteristic pollutants such as COD and TP in water that are difficult to degrade through biochemical pathways.

[0007] In a first aspect, embodiments of the present invention provide a removal system for recalcitrant and biodegradable multi-characteristic water pollutants, the removal system comprising:

[0008] The combined treatment unit includes a raw water storage and lifting unit, a hydroxyl oxidation unit, a degassing coupled adsorption and decolorization unit, a coagulation reaction unit, and a sedimentation and separation unit connected in sequence; wherein the hydroxyl oxidation unit and the degassing coupled adsorption and decolorization unit each have a meandering, extended partitioned reaction guide corridor (or partition wall) formed by spaced partition plates.

[0009] The pH adjustment component is connected to the raw water storage and lifting unit and the hydroxyl oxidation unit, respectively, and is used to pre-adjust the pH in the raw water storage and lifting unit to the first range and adjust the pH in the hydroxyl oxidation unit to the second range.

[0010] The active catalyst feeding component includes a first catalyst feeding component connected to the inlet near the head end of the hydroxyl oxidation unit, a second catalyst feeding component connected to the inlet near the head end of the degassing coupled adsorption and decolorization unit, and a third catalyst feeding device respectively disposed in the hydroxyl oxidation unit; wherein, the first catalyst feeding component and the second catalyst feeding component are used to add a catalytic activator solution with a preset flow rate ratio, and the third catalyst feeding device is used to add solid catalytic active granular material;

[0011] The oxidant feeding component includes a main oxidant component and an auxiliary oxidant component, each connected to a pipeline near the inlet of the hydroxyl oxidation unit. The main oxidant component and the auxiliary oxidant component are used to feed the first oxidant solution and the second oxidant solution, respectively.

[0012] The alkali adjustment component is connected to the front-middle point and the middle-rear point of the degassing coupled adsorption decolorization unit, respectively, and is used to adjust and neutralize the pH in the degassing coupled adsorption decolorization unit to the third range.

[0013] An adsorption and complexation feeding component includes an adsorbent component and a multi-calcium material component, each connected to a near-terminal corridor of the degassing coupled adsorption and decolorization unit. The adsorbent component and the multi-calcium material component are used to respectively add the adsorbent solution and the multi-calcium powder solution; and

[0014] The coagulant feeding component is connected to the inlet end of the coagulation reaction unit and is used to add coagulant.

[0015] The removal system according to the present invention includes a combined treatment unit, an acid-adjusting component, an active catalyst feeding component, an oxidant feeding component, an alkali-adjusting component, an adsorption-complexing feeding component, and a coagulant feeding component. Through the coupled isotopic reactions of the active catalyst feeding component and the oxidant feeding component, and the coordinated optimal pH adjustment of the acid-adjusting and alkali-adjusting components, it achieves highly efficient removal of recalcitrant organic pollutants (such as aromatic compounds and heterocyclic compounds). The highly efficient input of the adsorption-complexing feeding component further enhances the synergistic physicochemical removal of multiple pollutants with low microbial biochemical degradation efficiency, such as dissolved COD, color, recalcitrant total phosphorus, emerging water pollutants, and fluorides. Furthermore, it significantly reduces infrastructure investment, saves energy, chemical, and water consumption, and reduces periodic maintenance costs, thereby reducing greenhouse gas carbon dioxide equivalent emissions.

[0016] Secondly, embodiments of the present invention also provide a method for removing recalcitrant and biodegradable multi-characteristic water pollutants, based on the removal system described above.

[0017] The degassing coupled adsorption decolorization unit employs a first operating mode and a second operating mode, which are alternately regulated in a cyclical manner.

[0018] First operating mode: the second controllable switch is activated, the third controllable switch is deactivated, the fourth controllable switch is activated, and the adsorbent component and the multi-calcium material component are in a shutdown and closed state. Under this condition, the degassing coupled adsorption decolorization unit reaction zone forms a coupled spatial reaction partition of "Fenton oxidation reaction level II zone - pre-degassing zone - post-neutralization reaction zone".

[0019] Second operating mode: The second controllable switch is closed, the third controllable switch is open, the fourth controllable switch is closed, and the adsorbent component and the multi-calcium material component are in the operating state. Under this condition, the degassing coupled adsorption decolorization unit reaction zone forms a coupled spatial reaction partition of "Fenton oxidation reaction level II zone - neutralization and degassing zone - adsorption and multi-calcium complex feeding reaction zone".

[0020] According to the removal method of the present invention, the degassing coupled adsorption decolorization unit adopts a first operating mode and a second operating mode for cyclical alternation and control, which can greatly reduce reagent consumption, save energy consumption, and the combined process can further enhance the removal efficiency of residual characteristic pollutants that are difficult to degrade through biochemical pathways, such as COD, TP, and emerging pollutants (such as POPs, PPCPs, EDCs, PFAS).

[0021] Thirdly, embodiments of the present invention also provide a method for removing recalcitrant and multi-characteristic water pollutants, based on the removal system described above.

[0022] Specifically, the pH of the raw water storage and booster unit is adjusted to 3.0-4.5 by adding an acid regulator to pre-adjust the acidity, thus providing an acidic environment for the hydroxyl oxidation unit. The pH of the hydroxyl oxidation unit is then adjusted to 2.5-3.5 by adding an acid regulator to maintain the pH in the first third of the influent area of ​​the degassing-coupled adsorption-decolorization unit within a slightly acidic range of 3.5-4.8, thereby ensuring that the first third of the influent area of ​​the degassing-coupled adsorption-decolorization unit continues to participate in the acidic reaction environment of Fenton oxidation stage II.

[0023] Pre-adjusted acidity mode: The acid storage agent dosing component of the first acid adjustment component is interlocked with the first pH meter to control the amount of acid regulator, and the pH value is adjusted by PID within the range;

[0024] The main acidity adjustment mode: The acid storage agent dosing component of the second acid adjustment component is interlocked with the second pH meter and the third pH meter to control the dosage of acid regulator. The second pH meter feeds forward to control the frequency conversion frequency of the acid storage agent dosing component of the second acid adjustment component to adjust the dosage. The third pH meter feeds back to assist in monitoring and correcting the frequency conversion frequency of the acid storage agent dosing component of the second acid adjustment component. The pH value range is adjusted by PID.

[0025] According to the removal method of the present invention, the delivery frequency of the acid storage agent dosing component of the first acid conditioning component and the pumping component of the acid storage agent dosing component of the second acid conditioning component can be accurately achieved.

[0026] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows, and will also become apparent in part to those skilled in the art upon studying the description, or may be learned by practice of the invention. The objects and other advantages of the invention can be realized and obtained by means of the structures specifically pointed out in the description and drawings.

[0027] Those skilled in the art will understand that the objectives and advantages achievable with this invention are not limited to those specifically described above, and that the above and other objectives achievable with this invention will become clearer from the following detailed description. Attached Figure Description

[0028] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, are not intended to limit the scope of the invention. The components in the drawings are not drawn to scale but are merely illustrative of the principles of the invention. For ease of illustration and description of certain parts of the invention, corresponding portions in the drawings may be enlarged, i.e., may appear larger relative to other components in an exemplary device actually manufactured according to the invention. In the drawings:

[0029] Figure 1This is a schematic diagram of a removal system according to an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram of the degassing coupled adsorption decolorization unit in the first operating mode in a removal method according to an embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the degassing coupled adsorption decolorization unit in the removal method according to an embodiment of the present invention when it is in the second operating mode; and

[0032] Figure 4 This is a schematic diagram illustrating the improved removal efficiency of a removal system according to an embodiment of the present invention for residual recalcitrant COD.

[0033] Explanation of reference numerals in the attached figures:

[0034] 100. Remove system;

[0035] 11. Raw water storage and lifting unit; 12. Hydroxyl oxidation unit; 13. Degassing coupled adsorption and decolorization unit; 14. Coagulation reaction unit; 15. Sedimentation separation unit;

[0036] 21. Acid storage agent dosing components; 23. Acid storage agent dosing components; 22. Dosing pipeline components; 24. Dosing pipeline components;

[0037] 31. Catalyst dosing component; 32. Catalyst feeding pipeline; 33. Catalyst feeding pipeline; 3a'. Solid particulate catalyst head-end interception device; 3b'. Solid particulate catalyst tail-end interception device; 3'. Solid catalytic active particulate material;

[0038] 41. Main material oxidant component; 42. Auxiliary material oxidant component;

[0039] 51. Alkali storage agent dosing components and main dosing pipeline; 52. Branch pipelines; 53. Branch pipelines;

[0040] 61. Adsorbent component; 62. Multi-calcium material component;

[0041] 7. Coagulant feeding component;

[0042] 81. First mixing component; 82. Second mixing component; 83. Aeration component; 84. Third mixing component; 85. Sludge scraping and suction component;

[0043] 91. First pH meter; 92. Second pH meter; 93. Third pH meter; 94. Fourth pH meter;

[0044] 121. Reaction liquid reflux pipeline; 121a. Reflux pump components;

[0045] 131. Separated reaction flow channel;

[0046] 151a, Sludge return pipeline; 151b, Sludge discharge pipeline; 151a1, Pumping components; 151b1, Pumping components. Detailed Implementation

[0047] The objects and functions of the present invention, as well as the methods for achieving these objects and functions, will be clarified by referring to exemplary embodiments. However, the present invention is not limited to the exemplary embodiments disclosed below; it can be implemented in various forms. The purpose of this specification is merely to help those skilled in the art to comprehensively understand the specific details of the invention.

[0048] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0049] The ordinal numbers such as "first" and "second" used in this invention are merely identifiers and do not have any other meaning, such as a specific order. Moreover, for example, the term "first component" does not imply the existence of "second component," and the term "second component" does not imply the existence of "first component."

[0050] It should be noted that the terms “up,” “down,” “front,” “back,” “left,” “right,” “inner,” “outer,” and similar expressions used in this article are for illustrative purposes only and are not intended to be limiting.

[0051] This invention provides a system 100 for removing recalcitrant and multi-characteristic water pollutants. (Reference) Figure 1 The removal system 100 may include a combined processing unit, an acid adjustment component, an active catalyst feeding component, an oxidant feeding component, an alkali adjustment component, an adsorption complexation feeding component, a coagulant feeding component, a power component, and a pH measuring instrument component.

[0052] Specifically, the combined treatment unit may include a raw water storage and lifting unit 11, a hydroxyl oxidation unit 12, a degassing coupled adsorption decolorization unit 13, a coagulation reaction unit 14, and a sedimentation separation unit 15. The raw water storage and lifting unit 11 is connected to the wastewater to be treated via pipelines. Within the raw water storage and lifting unit 11, acid pre-conditioning is performed to provide an acidic environment for subsequent oxidation in the hydroxyl oxidation unit 12, with a hydraulic retention time of 20-40 minutes. The hydroxyl oxidation unit 12 and the degassing coupled adsorption decolorization unit 13 are the main units for the physicochemical reaction (equipped with a separation reaction guide corridor 131, such as the separation reaction guide corridor 131 within the degassing coupled adsorption decolorization unit 13), with a hydraulic retention time of 3-6 hours for the hydroxyl oxidation unit 12 and 2-4 hours for the degassing coupled adsorption decolorization unit 13. The coagulation reaction unit 14 promotes the modification and agglomeration of colloidal, particulate pollutants and suspended solids through electrochemical neutralization, flocculation, and adsorption bridging. The sedimentation separation unit 15 performs gravity separation of the reaction precipitate and wastewater, with a hydraulic retention time of 1-3 hours. A reaction liquid return pipeline 121 (with a return pump component 121a) can be installed at the end of the self-generating hydroxyl oxidation unit 12, allowing the reaction liquid to return to its inlet end at a return ratio of 3%-10% of the treatment capacity. This recirculates unreacted residual reagents back into the hydroxyl oxidation unit 12 system, reducing the loss of acids, catalysts, oxidants, and other chemical reagents, and improving reagent utilization. The sedimentation separation unit 15 can be equipped with a bottom sludge conveying system 151, including a sludge return pipeline 151a and a sludge discharge pipeline 151b, with corresponding pumping components 151a1 and 151b1. A small amount of sludge from the bottom of the sedimentation separation unit 15 is circulated back to the middle and rear points of the degassing coupled adsorption decolorization unit 13 via the sludge return pipeline 151a, with a return ratio of 5% to 12% of the treatment capacity. Excess sludge from the sedimentation separation unit 15 is discharged to the sludge storage unit to be dewatered via the sludge discharge pipeline 151b for subsequent sludge dewatering treatment. This limits the depth of the bottom sludge layer in the sedimentation separation unit 15, ensuring that there is a sufficient clean water protective layer above the sludge layer (the upper clean water layer is not less than 1.0 m). Figure 1 Not shown in the image.

[0053] The acid conditioning components may include piping components 21-24. Specifically, acid storage agent dosing components 21 and 23 mainly contain a solution storage tank and an acid-resistant pump for dispensing the solution. The pump is an intelligent pump with variable frequency precision for adjusting the dosage. Acid storage agent dosing component 21 can be interlocked with the first pH meter 91 (mentioned below) to control the dosage, and acid storage agent dosing component 23 can be interlocked with the second pH meter 92 (mentioned below) to control the dosage. Components 22 and 24 are dosing piping components (the piping is equipped with controllable switches for opening / closing / adjusting flow, such as valves). The acid conditioner can be concentrated sulfuric acid or dilute sulfuric acid, adjusting and controlling the pH within the raw water storage and lifting unit 11 to reach 3.0-4.5. The first pH meter 91 can be interlocked with the acid-resistant pump for dispensing the solution of acid storage agent dosing component 21. Within the pH range, PID control is used; when the pH value is below the lower threshold, the pump stops; when the pH value is above the upper threshold, the pump starts, for pre-adjusting the acidity. The pH within the hydroxyl oxidation unit 12 is adjusted to reach 2.5-3.5. The second pH meter 92 can be interlocked with the acid-resistant pumping component of the acid storage agent dosing unit 23 for control. Within the pH range, PID control is used; when the value is below the lower threshold, the pump stops; when the value is above the upper threshold, the pump starts. The second pH meter 92 feeds forward to control the frequency converter of the acid-resistant pumping component of the acid storage agent dosing unit 23 to adjust the dosage, while the third pH meter 93 provides feedback auxiliary monitoring and moderately corrects the frequency converter of the acid-resistant pumping component of the acid storage agent dosing unit 23. Thus, through the second pH meter 92 and the third pH meter 93, the precise frequency of the acid-resistant pumping component of the acid storage agent dosing unit 23 is achieved through feedforward main control and feedback monitoring / correction control, primarily regulating the acidity. By adjusting the pH range of the hydroxyl oxidation unit 12 to 2.5-3.5, it can be further ensured that the pH in the first third of the space near the inlet end of the degassing coupled adsorption decolorization unit 13 can still be maintained in the slightly acidic range of 3.5-4.8, thereby continuing the acidic reaction environment of the first third of the space in the degassing coupled adsorption decolorization unit 13 to participate in the second stage of Fenton oxidation reaction.

[0054] The active catalyst feeding component, for Fenton oxidation stage I, may include components 31-33 and solid particulate catalyst head-end interception device 3a' and solid particulate catalyst tail-end interception device 3b' respectively installed at the inlet and outlet of the hydroxyl oxidation unit 12. The interception devices 3a' and 3b' may be configured as mesh boxes each filled with solid catalytic active particles 3'. Specifically: 31 is the catalyst feeding component (mainly containing a solvent storage tank and a liquid pump component) and the main feeding pipeline. 32 and 33 are the catalyst feeding pipelines near the inlet of the hydroxyl oxidation unit 12 and the degassing coupled adsorption decolorization unit 13, respectively (the pipelines are equipped with controllable switches for opening / closing / adjusting flow rates, with the second controllable switch on the catalyst feeding pipeline 33). The flow rate ratio of the liquid entering the hydroxyl oxidation unit 12 and the degassing coupled adsorption decolorization unit 13 is (0.9~0.95):(0.05~0.1). The catalyst activator in catalyst dosing component 31 is preferably ferrous salt (Fe). 2+ The active catalytic powder 3' is mainly composed of ferrous sulfate, supplemented with ferrous chloride and magnetic powder Fe3O4. The mass ratio of these three components can be in the range of 1-3:1:0.2-0.5. After dry powder mixing, it is dissolved in water. The powder can be diluted to a 2%-10% liquid solution using tap water or purified water from the sedimentation separation unit 15 before being transported. The solid catalytic active granules 3' can be a mixture of activated alumina, molecular sieves, and titanium dioxide (TiO2) in a mass ratio of 1-3:1:0.2-0.5, with a volume filling ratio of 5%-15% in the hydroxyl oxidation unit 12. The solid catalytic active granules 3' are placed inside a fixed-position mesh box. The pores of the mesh box are smaller than the particle size of the active granules, ensuring that water can pass through while the active granules are blocked inside the mesh box. The ferrous salt (Fe3O4) is then used to dilute the active catalytic powder. 2+ A heterogeneous catalytic reaction system is formed by combining magnetic powder (Fe-II and Fe-III iron-based divalent states), activated alumina, molecular sieves, and titanium dioxide (TiO2).

[0055] The oxidant feeding component may include a main oxidant component 41 and an auxiliary oxidant component 42, both of which add oxidant to the inlet near the head end of the hydroxyl oxidation unit 12. Both the main oxidant component 41 and the auxiliary oxidant component 42 contain a solution storage tank and a solution pumping component. The main oxidant component 41 adds hydrogen peroxide (generally 27.5% or lower), i.e., the first oxidant solution. The auxiliary oxidant component 42 adds potassium persulfate (which can be prepared as a 2%~10% liquid dilution using tap water or purified water from the precipitation separation unit 15), i.e., the second oxidant solution. Oxidation and decomposition of persulfate can generate sulfate free radicals and hydroxyl free radicals. These two oxidant components 41 and 42 are provided in the aforementioned ferrous salt (Fe... 2+With the coupling of magnetic powder (iron-based bivalent states of divalent Fe-II and trivalent Fe-III), activated alumina, molecular sieve and titanium dioxide (TiO2), a heterogeneous mixture of sulfate radicals and hydroxyl radicals (·OH) is formed, forming a catalytic activation-persulfate-Fenton co-oxidation system.

[0056] The alkali conditioning component may include piping components 51-53. Specifically: 51 is the alkali storage agent dosing component and main dosing pipeline, primarily containing a storage tank and an alkali-resistant pumping component. The pumping component is an intelligent pump with variable frequency precision for adjusting the dosage, which is interlocked with 93 or 94 (mentioned below) to control the dosage. 52 and 53 are branch pipelines that allow the dosing agent to enter the pre-middle and mid-rear points of the degassing coupled adsorption decolorization unit 13, respectively. The pipelines are equipped with controllable switches for opening / closing and adjusting the flow rate; a third controllable switch is installed on branch pipeline 52, and a fourth controllable switch is installed on branch pipeline 53. The alkali conditioner can be liquid sodium hydroxide, used to adjust and neutralize the pH within the degassing coupled adsorption decolorization unit 13 to maintain a pH of 7.0-8.5. The third pH meter 93 or the fourth pH meter 94 is interlocked with the alkali storage agent dosing component and the alkali-resistant pumping component of the dosing main pipeline 51. The pH value is adjusted by PID within the range. When the value is lower than the lower threshold, the pump is started; when the value is higher than the upper threshold, the pump is stopped.

[0057] The connection point between the branch pipe 52 and the degassing coupled adsorption decolorization unit 13 is at least one corridor away from the first end corridor of the degassing coupled adsorption decolorization unit 13.

[0058] The adsorption and complexation feeding component may include an adsorbent component 61 and a multi-calcium material component 62, both of which are added to the near-tail end corridor of the degassing coupled adsorption and decolorization unit 13. Both the adsorbent component 61 and the multi-calcium material component 62 contain a solution storage tank and a solution pumping component. The adsorbent component 61 is activated carbon for coal-based wastewater (with an iodine adsorption value of not less than 750 mg / g and a methylene blue adsorption value of not less than 110 mg / g), supplemented with adsorption resin in a well-mixed ratio (the mass ratio of activated carbon to resin is 1~3:0.3~0.6). 62 is a mixed multi-calcium powder component, using calcium aluminate, calcium hydroxide, calcium chloride, and calcium carbonate in a mixed ratio. The total mass of the mixture is approximately 70%~80% calcium aluminate, 10%~20% calcium hydroxide, and approximately 2.5%~5% each of calcium chloride and calcium carbonate. The mixed powder can be prepared into a 2%~10% liquid dilution using tap water or purified water from the sedimentation and separation unit 15 before being transported. The adsorbent component 61 targets the residual organic pollutants, emerging pollutants (such as POPs, PPCPs, EDCs, PFAS), total phosphorus (such as phytic acid and phytates with phosphorus substituents), and colored functional groups in the wastewater after heterogeneous oxidation by the self-generated hydroxyl oxidation unit 12, which are still present as soluble, recalcitrant components. It further removes these pollutants through enhanced dual adsorption. The multi-calcium material component 62 assists the adsorbent component 61 and, together with the aforementioned total phosphorus, fluorides, and colored functional groups targeting the recalcitrant organic or inorganic phosphorus components, forms calcium fluoride and complexes such as iron phosphate and calcium phosphate through iron (Fe-III) and calcium ions. This process migrates the characteristic pollutants from the aqueous phase to the solid phase, where they are co-adsorbed, flocculated, and precipitated for removal.

[0059] The coagulant feeding component 7 adds the coagulant to the near-end corridor of the coagulation reaction unit 14. It may include a solvent storage tank and a liquid pumping component. The coagulant is a mixed feedstock, using anionic PAM (polyacrylamide) and sodium alginate in a specific ratio. The total mass of the mixture is approximately 70%–85% PAM and 15%–30% sodium alginate. The mixed powder can be diluted to a concentration of 0.8‰–2.0‰ using tap water or purified water from the sedimentation and separation unit 15 before being transported.

[0060] The power components may include a first stirring component 81, a second stirring component 82, an aeration component 83, a third stirring component 84, and a sludge scraping and suction component 85. Components 81-84 provide stirring or aeration power one-to-one to the raw water storage and lifting unit 11, the hydroxyl oxidation unit 12, the degassing coupled adsorption and decolorization unit 13, and the coagulation reaction unit 14. The sludge scraping and suction component 85 performs solid-liquid separation of sludge and water within the sedimentation and separation unit 15, ensuring that the upper clear liquid, achieving the expected purification efficiency, is discharged, and the bottom sludge is periodically removed from the system.

[0061] pH measuring instrument components may include a first pH meter 91 installed in the raw water storage and lifting unit 11, a second pH meter 92 installed in the hydroxyl oxidation unit 12, and a third pH meter 93 and a fourth pH meter 94 installed in the inlet head region and inlet tail region of the degassing coupling adsorption decolorization unit 13, respectively, for monitoring the pH of the reaction liquid at the installation location of the corresponding unit.

[0062] In summary, the removal system 100 of the present invention achieves highly efficient removal of recalcitrant organic pollutants (such as aromatic compounds and heterocyclic compounds) by coupling isotopic reactions of the active catalyst feeding component and the oxidant feeding component, and by linking the acid adjustment component and the alkali adjustment component to adjust the optimal reaction pH environment. Through the efficient input of the adsorption and complexation feeding component and the reasonable reflux of the circulating liquid, the synergistic physicochemical removal of multiple pollutants with low microbial biochemical degradation efficiency, such as soluble COD, color, recalcitrant total phosphorus, emerging water pollutants, and fluorides, can be further enhanced. For example, the COD index (COD of recalcitrant long-chain functional group recalcitrant organic pollutants) can be effectively removed. nb For the removal of COD, compared to existing degradation technologies such as conventional Fenton oxidation, Fenton-like oxidation, or ozone-aerated biological filters, this method is more effective. nb With a removal rate of 30%~45%, it can further guarantee a significant improvement in removal efficiency of 20%~40%, while greatly reducing infrastructure investment, saving energy, material and water consumption, and periodic maintenance costs, and reducing greenhouse gas carbon dioxide equivalent emissions. Significant environmental benefits: After wastewater undergoes secondary biological degradation treatment, the stubborn organic pollutants COD (Chemical Oxygen Demand) in the raw water are significantly reduced. nb When the concentration of COD remains in the range of 80-110 mg / L, this coupled enhancement technology can be used to control and remove it, ensuring that the overall effluent is better than Class A, and that the COD reaches a concentration of 30-50 mg / L or lower (e.g., Figure 4 (Example). Simultaneously, it can ensure that the color is reduced to below 30 mg / L. When the total phosphorus in the raw water that is difficult to biodegrade or degraded by coagulation and sedimentation is in the range of 0.3~1.2 mg / L, it can be reduced to 0.15~0.40 mg / L by adjusting and removing it using this technology, with orthophosphate reduced to below 0.05 mg / L. It also has a good oxidative removal effect on emerging pollutants in water.

[0063] Secondly, the present invention also provides a removal method based on the removal system 100 of the above embodiments.

[0064] The following will be based on Figure 2 and Figure 3 The process of the removal method in this embodiment of the invention is briefly described.

[0065] Figure 2 , Figure 3 The two main control timing alternation modes of the degassing coupled adsorption decolorization unit 13 are adopted in a cascade cyclic control (the first operating mode is followed by the second operating mode, and then back to the first operating mode, and so on repeatedly). The first operating mode has a running time of 0~30 min and the preset time T1 parameter is adjustable. The second operating mode follows the first operating mode and the running time is also 0~30 min and the preset time T2 parameter is adjustable.

[0066] For example, when T1 and T2 are set to 30 minutes, the system runs in the first operating mode for 30 minutes, then switches to the second operating mode for 30 minutes, and then switches back to the first operating mode, repeating this cycle. This alternating operation significantly reduces reagent consumption, saves energy, and, combined with the process, enhances the removal efficiency for residual characteristic pollutants that are difficult to degrade through biochemical pathways, such as COD, TP, and emerging pollutants (e.g., POPs, PPCPs, EDCs, PFAS).

[0067] First operating mode: The second controllable switch and corresponding pumping components are started, the third controllable switch is closed, the fourth controllable switch and corresponding pumping components are turned on, and the adsorbent component and the multi-calcium material component are in a shut-down state. Under this condition, the degassing coupled adsorption decolorization unit reaction zone forms a coupled spatial reaction partition of "Fenton oxidation reaction level II zone - pre-degassing zone - post-neutralization reaction zone".

[0068] Second operating mode: The second controllable switch and corresponding pumping components are closed, the third controllable switch and corresponding pumping components are open, the fourth controllable switch is closed, and the adsorbent component and the multi-calcium material component are in the operating state. Under this condition, the degassing coupled adsorption decolorization unit reaction zone forms a coupled spatial reaction partition of "Fenton oxidation reaction level II zone - neutralization and degassing zone - adsorption and multi-calcium complex feeding reaction zone".

[0069] Thirdly, the present invention also provides a removal method based on the removal system 100 of the above embodiments.

[0070] Specifically, the pH of the raw water storage and booster unit is adjusted to 3.0-4.5 by adding an acid regulator to pre-adjust the acidity, thus providing an acidic environment for the hydroxyl oxidation unit. The pH of the hydroxyl oxidation unit is then adjusted to 2.5-3.5 by adding another acid regulator to maintain the pH in the first third of the influent area of ​​the degassing-coupled adsorption-decolorization unit within a slightly acidic range of 3.5-4.8. This ensures that the first third of the influent area of ​​the degassing-coupled adsorption-decolorization unit continues to participate in the acidic reaction environment of Fenton oxidation stage II within the degassing-coupled adsorption-decolorization unit.

[0071] Among them, the pre-adjusted acidity mode: the acid storage agent dosing component (pumping component) of the first acid adjustment component is interlocked with the first pH meter to control the amount of acid regulator, and the pH value range is adjusted by PID.

[0072] The main acidity adjustment mode: The acid storage agent dosing component of the second acid adjustment component is interlocked with the second pH meter and the third pH meter to control the dosage of acid regulator. The second pH meter feedforward controls the frequency conversion frequency of the (pumping component) of the acid storage agent dosing component of the second acid adjustment component to adjust the dosage. The third pH meter feedback assists in monitoring and correcting the frequency conversion frequency of the (pumping component) of the acid storage agent dosing component of the second acid adjustment component. The pH value range is adjusted by PID.

[0073] Other embodiments of the invention will be readily conceived and understood by those skilled in the art in conjunction with the description and practice of the invention disclosed herein. The descriptions and embodiments are to be considered exemplary only, and the true scope and spirit of the invention are defined by the claims.

Claims

1. A method for the removal of a recalcitrant, biologically-degradable, multi- characteristic water pollutant, characterized by, The removal method comprises a removal system, which comprises: a combined treatment unit, comprising sequentially connected raw water storage and lifting unit, hydroxyl radical generating unit, degassing and adsorption decoloring unit, coagulation reaction unit and sedimentation separation unit; wherein the hydroxyl radical generating unit and the degassing and adsorption decoloring unit each have a windingly extended partition reaction channel formed by spaced partition plates; an acid adjusting component, which is connected to the raw water storage and lifting unit and the hydroxyl radical generating unit respectively, and is used for pre-adjusting the pH in the raw water storage and lifting unit to a first interval and adjusting the pH in the hydroxyl radical generating unit to a second interval; an active catalyst feeding component, which comprises a first catalyst feeding component connected to the inlet near the head of the hydroxyl radical generating unit, a second catalyst feeding component connected to the inlet near the head of the degassing and adsorption decoloring unit, and a third catalyst feeding device arranged in the hydroxyl radical generating unit respectively; wherein the first catalyst feeding component and the second catalyst feeding component are used for feeding a preset flow ratio of catalyst activator liquid, and the third catalyst feeding device is used for feeding solid catalyst active granules; the second catalyst feeding component comprises a second catalyst feeding pipeline with a second controllable switch connected to the catalyst feeding component; an oxidant feeding component, which comprises a main oxidant feeding component and an auxiliary oxidant feeding component each connected to the inlet near the head of the hydroxyl radical generating unit, and is used for feeding first oxidant liquid and second oxidant liquid respectively; a base adjusting component, which is connected to the front middle point and the middle rear point of the degassing and adsorption decoloring unit respectively, and is used for adjusting and controlling the pH in the degassing and adsorption decoloring unit to a third interval; the base adjusting component comprises a first base adjusting feeding pipeline component with a third controllable switch and a second base adjusting feeding pipeline component with a fourth controllable switch, which are each connected to the front middle point and the middle rear point of the degassing and adsorption decoloring unit respectively; an adsorption complex feeding component, which comprises an adsorbent component and a calcium material component each connected to the near-end channel of the degassing and adsorption decoloring unit, and is used for feeding adsorbent liquid and calcium powder multi-material liquid respectively; and a coagulant feeding component, which is connected to the inlet head of the coagulation reaction unit, and is used for feeding coagulant; wherein the degassing and adsorption decoloring unit adopts a first operation mode and a second operation mode to be cyclically and alternately regulated, the first operation mode: the second controllable switch is started, the third controllable switch is closed, the fourth controllable switch is opened, and the adsorbent component and the calcium material component are in a shutdown state, in this case, the reaction zone of the degassing and adsorption decoloring unit forms a coupled space reaction partition of "Fenton oxidation reaction II stage area - front degassing area - rear neutralization reaction area"; the second operation mode: the second controllable switch is closed, the third controllable switch is opened, the fourth controllable switch is closed, and the adsorbent component and the calcium material component are in a running state, in this case, the reaction zone of the degassing and adsorption decoloring unit forms a coupled space reaction partition of "Fenton oxidation reaction II stage area - neutralization and degassing area - adsorption and calcium complex feeding reaction area".

2. The removal method according to claim 1, characterized by, The acid adjusting component includes a first acid adjusting component with a controllable switch connected to the raw water storage and lifting unit and a second acid adjusting component with a controllable switch connected to the hydroxyl radical production unit, the first acid adjusting component is used to pre-adjust the pH in the raw water storage and lifting unit to 3.0-4.5, and the second acid adjusting component is used to adjust the pH in the hydroxyl radical production unit to 2.5-3.

5. The first acid adjusting component and the second acid adjusting component each include an acid storage and dosing component and a dosing pipeline component with a controllable switch connected thereto.

3. The removal method according to claim 1, characterized by, The first catalyst dosing component includes a first catalyst dosing pipeline with a controllable switch connected to the catalyst dosing component; the third catalyst dosing device includes a meshed interception device arranged at the inlet and outlet of the hydroxyl radical production unit to prevent the filler from running out of the hydroxyl radical production unit, and a solid catalytically active granular material filled in the interception device; The catalytic activator is a 2%-10% liquid diluent prepared by dissolving a powder in water, wherein the components of the powder include ferrous sulfate, ferrous chloride and magnetic powder Fe3O4, and the mass ratio of each component is 1-3:1:0.2-0.5; the components of the solid catalytically active granular material include activated alumina, molecular sieve and titanium dioxide, and the mass ratio of each component is 1-3:1:0.2-0.5, and the volume filling ratio of the solid catalytically active granular material in the hydroxyl radical production unit is 5%-15%; and / or The flow rate ratio of the catalytic activator liquid dosed by the first catalyst dosing component and the second catalyst dosing component is (0.9-0.95):(0.05-0.1).

4. The removal method according to claim 1, characterized by, The main and auxiliary oxidant components each include a storage tank and a liquid pumping component, and the first and second oxidant liquids are hydrogen peroxide and potassium persulfate diluent, respectively.

5. The removal method according to claim 1, wherein The base adjusting agent is a sodium hydroxide solution.

6. The removal method according to claim 1, wherein The adsorbent liquid is a mixture of coal sewage activated carbon and adsorbent resin in a mass ratio of 1-3:0.3-0.6, wherein the iodine adsorption value of the coal sewage activated carbon is not less than 750 mg / g, and the methylene blue adsorption value is not less than 110 mg / g. The calcium powder multi-liquid is a 2%-10% liquid diluent prepared by dissolving calcium powder multi-ingredient in water, wherein the components of the calcium powder multi-ingredient include calcium aluminate, calcium hydroxide, calcium chloride and calcium carbonate, wherein the mass ratio of calcium aluminate is 70%-80%, the mass ratio of calcium hydroxide is 10%-20%, and the mass ratio of calcium chloride and calcium carbonate is each 2.5%-5%.

7. The removal method according to claim 1, characterized by, Further comprising: The power component includes a first stirring component, a second stirring component, an aeration component, a third stirring component and a mud scraping component arranged in the raw water storage and lifting unit, the hydroxyl radical production unit, the degassing coupled adsorption decolorization unit, the coagulation reaction unit and the sedimentation separation unit, respectively; and / or pH measuring instrument components, including a first pH meter arranged in the raw water storage and lifting unit, a second pH meter arranged in the hydroxyl radical generating unit, and a third pH meter and a fourth pH meter arranged at the inlet head and tail of the deaeration and adsorption decolorization unit, respectively, for monitoring the pH of the reaction solution at the corresponding positions.

8. The removal method according to claim 1, characterized by, Further comprising: A reaction solution reflux pipeline is arranged at the end of the hydroxyl radical generating unit and communicates with the inlet head and tail of the reaction solution, so as to realize reflux of the reaction solution at a preset reflux ratio of the treatment capacity; wherein the preset reflux ratio of the treatment capacity is 3% to 10%, A sludge conveying system connected to the bottom of the sedimentation and separation unit, the sludge conveying system comprising: A sludge reflux pipeline component for refluxing the bottom sludge at a preset reflux ratio of the treatment capacity to the middle and rear point of the deaeration and adsorption decolorization unit, wherein the preset reflux ratio of the treatment capacity is 5% to 12%; and / or A sludge discharge pipeline component for discharging excess sludge at the bottom to limit the depth of the sludge layer in the sedimentation and separation unit.

9. The removal method of claim 1, wherein, The pH in the raw water storage and lifting unit is adjusted and controlled to 3.0 to 4.5 by adding an acid regulator, which is a pre-adjusted acidity, to provide an acidic environment for the oxidation of the hydroxyl radical generating unit; the pH in the hydroxyl radical generating unit is adjusted and controlled to 2.5 to 3.5 by adding an acid regulator, which is a main-adjusted acidity, to further ensure that the pH in the first third area near the inlet head of the deaeration and adsorption decolorization unit can still be maintained in the slightly acidic range of 3.5 to 4.8, thereby continuing the acidic reaction environment of the first third area near the inlet head of the deaeration and adsorption decolorization unit to participate in the Fenton oxidation reaction II stage; wherein The pre-adjusted acidity mode: the acid storage dosing component of the first acid adjusting component is connected to the first pH meter to control the amount of acid regulator, and the pH value range is adjusted by PID; The main-adjusted acidity mode: the acid storage dosing component of the second acid adjusting component is connected to the second pH meter and the third pH meter to control the amount of acid regulator, the second pH meter feeds forward to control the frequency of the acid storage dosing component of the second acid adjusting component to adjust the delivery amount, the third pH meter feeds backward to assist in monitoring and correcting the frequency of the acid storage dosing component of the second acid adjusting component, and the pH value range is adjusted by PID.

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