A wastewater treatment system for Citrus aurantium pharmaceuticals

Abstract

The present application relates to the field of pharmaceutical wastewater treatment technology, and discloses a system for treating pharmaceutical wastewater derived from Citrus aurantium, comprising a pretreatment unit, wherein wastewater enters the pretreatment unit, and colloidal proteins in the wastewater are removed by flocculation, and the generated flocculated impurities are formed into agglomerates, and the impurities in the wastewater are filtered by the agglomerates; a molecular imprinting treatment unit, which receives the wastewater output by the pretreatment unit, and adopts Fe3O4@SiO2 core-shell adsorption material with hesperidin as a template as an adsorbent, and cooperates with magnetic field fluidization to carry out targeted absorption of flavonoids in the wastewater, and cooperates with magnet assistance and regeneration process to complete the recovery of flavonoids and regeneration of adsorbent; and a bioelectrochemical reaction unit. Through the synergistic action of multiple mechanisms, the system realizes the step-by-step decomposition and mineralization of complex organic matter, especially showing excellent removal effect on pollutants such as macromolecular drug residues and pigments that are difficult to treat by traditional processes, ensuring that the effluent water quality is stable and meets the standards.

Description

Technical Field

[0001] The invention relates to the technical field of pharmaceutical wastewater treatment, in particular to a system for treating pharmaceutical wastewater produced from Citrus aurantium immaturus. Background Art

[0002] Wastewater treatment is crucial in pharmaceutical processing. Existing technologies for pharmaceutical wastewater treatment have significant limitations for the high concentrations of flavonoids (such as hesperidin and naringin) found in Citrus aurantium wastewater. Conventional physical and chemical methods (such as coagulation and sedimentation, and activated carbon adsorption) have a removal efficiency of less than 30% for soluble flavonoids, and adsorbent regeneration costs are high (>$0.5 / kg). While biological treatment technologies (such as activated sludge and biofilm processes) can degrade some organic matter, the antibacterial properties of flavonoids can reduce microbial activity by more than 50%, requiring sludge aging to exceed 20 days to maintain system stability, resulting in significant operating costs. Furthermore, while multi-stage cascade processes (such as Fenton oxidation-biofilm coupling) can improve treatment efficiency, the addition of chemicals (such as H₂O₂) and membrane fouling increase the cost per ton of water to $2.2-2.8, and produce sludge with a high water content of 0.37 kg / m³, further increasing the disposal burden.

[0003] Existing deep treatment technologies (such as reverse osmosis membranes and advanced oxidation processes) face key challenges in the application of flavonoid wastewater. Reverse osmosis membranes are easily clogged by colloidal substances in the wastewater, resulting in flux decay rates exceeding 60% per month and an inability to selectively recover high-value-added components. Fenton oxidation relies on excessive reagents, leading to iron sludge contamination (0.3 kg / m³), and non-selective oxidation of hydroxyl radicals (·OH) results in energy consumption as high as 0.7 kWh / kg COD. While research has attempted to incorporate molecular imprinting technology into wastewater treatment, traditional imprinted materials suffer from poor pore size matching and high mass transfer resistance, resulting in an adsorption capacity for hesperidin less than 30 mg / g. Furthermore, existing technology combinations often remain at the simple superposition stage, failing to achieve a closed energy-material loop (such as in-situ H₂O₂ utilization and algae resource recovery). This results in poor system synergy and low resource recovery rates, making it difficult to meet the needs of a green and low-carbon transition. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the present invention provides a Citrus aurantium pharmaceutical wastewater treatment system, which solves the problems existing in traditional pharmaceutical wastewater treatment systems.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a system for treating pharmaceutical wastewater from Citrus aurantium immaturum, comprising:

[0006] Pretreatment unit: wastewater enters the pretreatment unit, where colloidal proteins in the wastewater are removed through flocculation, and the generated flocculated impurities are formed into agglomerates, through which the impurities in the wastewater are filtered;

[0007] The molecular imprinting treatment unit receives the wastewater output by the pretreatment unit and uses the Fe3O4@SiO2 core-shell adsorption material with hesperidin as a template as an adsorbent. It combines the magnetic field fluidization effect to carry out targeted absorption of flavonoids in the wastewater. It also combines magnet assistance and regeneration processes to complete the recovery of flavonoids and regeneration of the adsorbent.

[0008] The bioelectrochemical reaction unit uses a graphene aerogel loaded with electroactive bacteria as the anode and a carbon fiber cloth loaded with Fe / N co-doped carbon quantum dots as the cathode. The graphene aerogel is surface-modified with carboxylated carbon quantum dots, with a specific surface area of ≥1500 m² / g and a pore size distribution consisting of 0.8-2 nm micropores and 5-10 nm mesopores. The micropores are used to adsorb small molecule pollutants, and the mesopores are used to promote bacterial colonization. Wastewater is output from the molecular imprinting treatment unit and enters the bioelectrochemical reaction unit. After the organic pollutants in the wastewater are removed through an oxidation reaction at the anode, a reduction reaction occurs at the cathode to generate H2O2.

[0009] The wastewater discharged from the bioelectrochemical reaction unit enters the microalgae photocatalytic coupling unit. The microalgae photocatalytic coupling unit includes a photobiofilm carrier. The base of the photobiofilm carrier is a carbon fiber woven cloth, with a TiO2 nanowire array densely arranged below and a double algae symbiotic membrane arranged above. It is used to absorb small molecular organic matter in the wastewater, and the H2O2 generated by the cathode is input into the TiO2 nanowire array through the guide tube, and the reaction generates OH to degrade the difficult-to-degrade organic matter in the wastewater.

[0010] Preferably, the pretreatment unit includes a wastewater collection pool, and wastewater in the pharmaceutical process is discharged into the wastewater collection pool for centralized storage. An impurity treatment module is provided on one side of the wastewater collection pool, and the impurity treatment module includes a base, and a plurality of filter columns are embedded and fixedly connected to the upper part of the base. The water inlets at the bottom of the plurality of filter columns are connected in parallel and connected to the inside of the wastewater collection pool through a pumping device. A valve is independently provided at the water inlet of each filter column, a stirring device is provided in the center of the filter column, and a flocculant injection port is provided on the top. The flocculant is a cationic The flocculant is stirred and mixed by a stirring device for stirring the wastewater and the flocculant in the filter column. The upper part of the filter column is covered and fixed with a filter screen 1, and a water outlet is provided above the filter screen 1. The water outlets of multiple filter columns are connected in parallel, and the filtered wastewater flows into the molecular imprinting treatment unit through the parallel connection of the water outlets. A sewage outlet is provided at the lower middle part of the filter column, and an independent valve is provided at the sewage outlet. A flocculation treatment chamber is fixedly connected to one side of the base. The interior of the flocculation treatment chamber is divided into an inner flocculation accumulation chamber and an outer water filtration chamber, wherein the interior of the flocculation accumulation chamber is connected to the filter. The sewage outlet of the filter column is connected, and a piston is provided in the flocculent accumulation chamber. A driving device is provided at one end of the flocculent accumulation chamber for driving the piston to move in the flocculent accumulation chamber. The other end is an opening structure, and a plurality of limit rods are fixedly connected to the outer wall of the opening. The ends of the plurality of limit rods are fixedly connected to the limit plates. A sealing cover is sleeved on the outer wall of the limit rod and slidably connected. The sealing cover is connected to the limit plate by a spring. The sealing cover is embedded in the opening of the flocculent accumulation chamber and sealed by the spring force. The water filter chamber is opened near the outside of the opening of the flocculent accumulation chamber, and the water filter The cavity is connected with the flocculent accumulation cavity, and a second filter screen is provided at the connection point between the two. The drain outlet of the water filter cavity extends to the wastewater collection pool through a pipe. When the driving device pushes the piston to move toward the opening of the flocculent accumulation cavity, the wastewater in the flocculent accumulation cavity is filtered through the second filter screen under the action of air pressure and then flows back into the wastewater collection pool through the pipe. At the same time, the flocculent impurities in the flocculent accumulation cavity are compressed to discharge water and are located between the sealing cover and the piston. When the thrust of the driving device exceeds the spring elastic force threshold, the sealing cover is separated from the opening of the flocculent accumulation cavity, and the flocculent impurities are squeezed out to the outside.

[0011] Preferably, the molecular imprinting treatment unit includes an adsorption tank, the top of the adsorption tank is open, and a porous plate water distributor is embedded and fixed below the opening. An adsorbent feeding port is provided on the tank body between the top opening and the porous plate water distributor. An alternating magnetic field fluidization device is provided in the lower part of the adsorption tank to maintain the adsorbent in a rotating and fluidized state. A support layer is provided in the adsorption tank, which is located within the magnetic field coverage of the alternating magnetic field fluidization device. The support layer is composed of a conical porous sintered plate for intercepting the adsorbent. A drainage end and a backflush end are sequentially provided at the bottom of the adsorption tank. The drainage end is connected to the water inlet of the bioelectrochemical reaction unit through a pipeline, and an ultraviolet sensor is provided at the drainage end for detecting the concentration of hesperidin in the discharged wastewater. The backflush end is connected to the output end of the backflush device. An adsorbent discharge portion is provided on the tank body above the support layer, and the discharge portion extends into the permanent magnetic separation device. The saturated adsorbent discharged from the adsorbent discharge portion is collected by the permanent magnetic separation device and input into the desorption device. The saturated adsorbent is regenerated by the desorption device and reused. A differential pressure transmitter is also provided at the support layer for real-time monitoring of the pressure difference changes of the support layer.

[0012] Preferably, in the Fe3O4@SiO2 core-shell adsorption material, the Fe3O4 magnetic core is ellipsoidal, the SiO2 shell thickness is 6.5-7.5nm, the mesopore diameter is 0.8-1.2nm, and the imprinting site density is ≥3.2×10 15 sites / cm².

[0013] Preferably, the alternating magnetic field fluidization device includes an electromagnetic coil array, which is composed of 12 groups of annular coils. The 12 groups of annular coils are embedded in the outer tank wall of the adsorption tank with the central axis of the adsorption tank as the center ring and are arranged in a circular array on the outer tank wall of the adsorption tank. A non-uniform alternating magnetic field is formed by controlling the current injected into the electromagnetic coil array. A water cooling system is also provided in the electromagnetic coil array to cool the electromagnetic coil.

[0014] Preferably, the permanent magnetic separation device includes a drum, the inner wall of the drum is a permanent magnetic part, and the outer wall is rotatably connected to the support seat, the outer wall of the drum is inlaid with and fixedly connected to an external gear, the outer wall of the support seat is fixedly connected to a driving motor, the output end of the driving motor is fixedly connected to a driving gear, the tooth end of the driving gear is meshed with the tooth end of the external gear, and the drum is driven by the driving motor to rotate along its axis, and a separation conveying trough is provided on the upper part of the drum, and the separation conveying trough is placed at an angle, the upper wall of one end of the separation conveying trough is in contact with the inner upper wall of the drum, and the outer wall of the other end is fixedly connected to the feed port of the desorption device, when the drum rotates, the adsorbent magnetically attracted to the inner wall of the drum is shoveled out by the upper wall of the separation conveying trough and falls into the separation conveying trough, and under the action of gravity, the adsorbent flows into the desorption device along the separation conveying trough.

[0015] Preferably, the bioelectrochemical reaction unit includes a reaction pool, in which an ion exchange membrane is provided. The ion exchange membrane is made of sulfonated polyetheretherketone, and the inner cavity of the reaction pool is divided into an anode chamber and a cathode chamber. The anode is arranged in the anode chamber, and a baffle assembly is also provided in the anode chamber to form an S-shaped flow channel. The cathode is arranged in the cathode chamber. The wastewater discharged from the molecular imprinting treatment unit enters the anode chamber, and after the organic pollutants in the wastewater are removed by oxidation reaction, it is injected into the microalgae photocatalytic coupling unit by the suction equipment. At the same time, the H+ generated by the oxidation reaction migrates to the cathode chamber through the ion exchange membrane to carry out the oxygen reduction reaction.

[0016] Preferably, the microalgae photocatalytic coupling unit includes a photobioreactor, which is made of a translucent polymethyl methacrylate material. The photobioreactor carrier is arranged inside the photobioreactor, and the outer wall of the photobioreactor located at the double algae symbiotic membrane is surrounded by a full-spectrum LED array, and the outer wall of the photobioreactor located at the TiO2 nanowire array is surrounded by an ultraviolet LED array.

[0017] The present invention provides a system for treating wastewater produced from pharmaceutical processing of Citrus aurantium. The system has the following beneficial effects:

[0018] 1. Through the synergistic effect of multiple mechanisms (adsorption-photocatalysis-biodegradation), the complex organic matter can be decomposed and mineralized step by step. In particular, it has an excellent removal effect on pollutants such as large molecular drug residues and pigments that are difficult to treat with traditional processes, ensuring that the effluent water quality is stable and meets the standards.

[0019] 2. By recycling high-value components and co-producing microalgae to form a resource cycle, a sustainable "waste-to-waste" operation model is established, significantly reducing the cost of treatment throughout the entire life cycle. For example, the present invention utilizes a molecularly imprinted treatment unit and uses Fe3O4@SiO2 core-shell materials for targeted adsorption of hesperidin, significantly improving the recovery rate of hesperidin. The algae powder produced in the microalgae photocatalytic coupling unit and the H2O2 produced by the bioelectrochemical reaction unit are used for synergistic degradation in the microalgae photocatalytic coupling unit. This achieves efficient purification and reuse of active ingredients in pharmaceutical wastewater, while simultaneously producing high-value-added algae-based products. This forms a closed-loop system of "pollutant removal-resource regeneration-energy recovery," promoting the transformation of wastewater treatment from energy-intensive to energy-efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a front perspective schematic diagram of the present invention;

[0021] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0022] Figure 3 It is a rear perspective schematic diagram of the present invention;

[0023] Figure 4 for Figure 3 Enlarged view of point B in the middle;

[0024] Figure 5 Schematic diagram of the structure of the impurity processing module in the present invention;

[0025] Figure 6 It is a structural schematic diagram of the flocculation treatment chamber in the present invention;

[0026] Figure 7 Schematic diagram of the structure of the molecular imprinting processing unit in the present invention;

[0027] Figure 8 Schematic diagram of the structure of the microalgae photocatalytic coupling unit in the present invention.

[0028] Among them, 1. molecular imprinting treatment unit; 101. adsorption tank; 102. porous plate water distributor; 103. adsorbent feeding port; 104. support layer; 105. electromagnetic coil array; 2. bioelectrochemical reaction unit; 201. reaction cell; 202. ion exchange membrane; 203. anode chamber; 204. cathode chamber; 205. baffle assembly; 3. microalgae photocatalytic coupling unit; 301. photobiofilm carrier; 302. photobioreactor; 303. full-spectrum LED array; 304. ultraviolet LED array; 4. Wastewater collection tank; 5. Impurity treatment module; 501. Base; 502. Filter column; 503. Filter screen 1; 6. Flocculant treatment chamber; 601. Flocculant accumulation chamber; 602. Water filter chamber; 603. Piston; 604. Limit rod; 605. Limit plate; 606. Sealing cover; 607. Spring; 608. Filter screen 2; 7. Permanent magnetic separation device; 701. Drum; 702. Support seat; 703. External gear; 704. Drive motor; 705. Driving gear; 706. Separation conveying trough; 8. Desorption device. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] Please see the attached Figure 1 -Attached Figure 8The embodiment of the present invention provides a system for treating pharmaceutical wastewater of Citrus aurantium, comprising a pretreatment unit, a molecular imprinting treatment unit 1, a bioelectrochemical reaction unit 2 and a microalgae photocatalytic coupling unit 3. Through the mutual cooperation of the above units, a technological breakthrough of molecular recognition-bioelectrochemistry-photobiological synergy is achieved, solving the core pain points of pharmaceutical wastewater treatment such as poor selectivity, low efficiency, high cost and waste of resources.

[0031] The detailed description of each unit is as follows:

[0032] Pretreatment unit, wastewater enters the pretreatment unit, colloidal protein in the wastewater is removed by flocculation, and the generated flocculated impurities are formed into agglomerates, and the impurities in the wastewater are filtered through the agglomerates; the pretreatment unit includes a wastewater collection tank 4, wastewater in the pharmaceutical process is discharged into the wastewater collection tank 4 for centralized storage, an impurity treatment module 5 is provided on one side of the wastewater collection tank 4, the impurity treatment module 5 includes a base 501, a plurality of filter columns 502 are embedded and fixedly connected to the upper part of the base 501, the bottom water inlets of the plurality of filter columns 502 are connected in parallel, and are connected to the inside of the wastewater collection tank 4 through a pumping device, and a valve is independently provided at the water inlet of each filter column 502, and the center of the filter column 502 is provided with a valve. A stirring device is provided, and a flocculant injection port is provided on the top. The flocculant is a cationic flocculant. The stirring device stirs and mixes the wastewater and the flocculant in the filter column 502. The upper part of the filter column 502 is covered and fixed with a filter screen 503. A water outlet is provided above the filter screen 503. The water outlets of multiple filter columns 502 are connected in parallel. The filtered wastewater flows into the molecular imprinting treatment unit 1 through the parallel connection of the water outlets. A sewage outlet is provided at the lower middle part of the filter column 502, and an independent valve is provided at the sewage outlet. A flocculation treatment chamber 6 is fixedly connected to one side of the base 501. The interior of the flocculation treatment chamber 6 is divided into an inner flocculation accumulation chamber 601 and an outer water filtration chamber 602. The interior is connected to the sewage outlet of the filter column 502, and a piston 603 is provided in the flocculent accumulation chamber 601. A driving device is provided at one end of the flocculent accumulation chamber 601 for driving the piston 603 to move in the flocculent accumulation chamber 601. The other end is an opening structure, and a plurality of limiting rods 604 are fixedly connected to the outer wall of the opening. The ends of the plurality of limiting rods 604 are fixedly connected to the limiting plate 605. The outer wall of the limiting rod 604 is sleeved and slidably connected with a sealing cover 606. The sealing cover 606 and the limiting plate 605 are connected by a spring 607. The elastic force of the spring 607 causes the sealing cover 606 to be embedded in the opening of the flocculent accumulation chamber 601 and sealed. The water filter chamber 602 is opened near the opening of the flocculent accumulation chamber 601 On the outside, the water filter chamber 602 is connected with the flocculent accumulation chamber 601, and a filter screen 2 608 is provided at the connection point between the two. The drain outlet of the water filter chamber 602 extends to the wastewater collection tank 4 through a pipe. When the driving device pushes the piston 603 toward the opening of the flocculent accumulation chamber 601, the wastewater in the flocculent accumulation chamber 601 is filtered through the filter screen 2 608 under the action of air pressure, and then flows back into the wastewater collection tank 4 through the pipe. At the same time, the flocculent impurities in the flocculent accumulation chamber 601 are compressed to discharge water and are located between the sealing cover 606 and the piston 603. When the thrust of the driving device exceeds the elastic threshold of the spring 607, the sealing cover 606 is separated from the opening of the flocculent accumulation chamber 601, and the flocculent impurities are squeezed out to the outside.

[0033] In order to solve the problems of intermittent discharge of pharmaceutical wastewater and large fluctuations in water quality and quantity, a wastewater collection pool 4 is set up to centrally introduce the discharged wastewater into the wastewater collection pool 4 for storage and then uniformly treated. The wastewater collection pool 4 has a large capacity, which solves the problem of intermittent discharge of wastewater by exchanging space for time. At the same time, the wastewater is centrally mixed to achieve the effect of balanced wastewater quality.

[0034] Secondly, since the wastewater contains a large amount of colloidal proteins and impurities, it will cause physical blockage of the imprinting sites in the molecular imprinting treatment unit 1. To solve this problem, an additional impurity treatment module 5 is provided. It is distributed at the front end of the molecular imprinting treatment unit 1. It extracts wastewater from the wastewater collection tank 4 and injects it from the bottom of the filter column 502. With the addition of flocculants and stirring, the impurities and colloidal proteins in the wastewater are flocculated. As this process continues, the generated flocculated impurities form agglomerates. The agglomerates are suspended in the lower part of the filter column 502 and their volume gradually increases. The impurities in the wastewater are intercepted by the agglomerates, playing a filtering role. At this time, the wastewater in the filter column 502 is stratified. That is, the upper layer is the water body filtered by the agglomerates, from which most of the colloidal proteins and impurities are removed. When it overflows, it enters the molecular imprinting treatment unit 1. The filter screen 503 plays the role of isolating suspended matter in the early stage.

[0035] At the same time, as the treatment continues, the volume of the agglomerated aggregates becomes too large. At this time, the agglomerated aggregates are discharged into the flocculation treatment chamber 6. Specifically, the agglomerated aggregates and part of the water flow enter the flocculation accumulation chamber 601 together. When a certain number is reached, the driving device pushes the piston 603 to move toward the opening of the flocculation accumulation chamber 601. At this time, under the action of the piston 603, the effective space of the flocculation accumulation chamber 601 gradually decreases, and then the space formed by the flocculation accumulation chamber 601 and the water filtration chamber 602 is gradually compressed and reduced, and the pressure in the space increases. The wastewater in the flocculation accumulation chamber 601 is filtered through the filter screen 2 608 under the action of air pressure and then flows back into the wastewater collection tank 4 through the pipeline. At the same time, the flocculated impurities in the flocculation accumulation chamber 601 are compressed to discharge water and are located between the sealing cover 606 and the piston 603. When the thrust of the driving device exceeds the elastic threshold of the spring 607, the sealing cover 606 is separated from the opening of the flocculation accumulation chamber 601, and the flocculated impurities are squeezed out to the outside for further treatment.

[0036] The impurity treatment module 5 is provided with multiple filter columns 502, whose water inlets and outlets are both connected in parallel, and each filter column 502 is provided with an independently controlled valve at its water inlet. This solution significantly improves the dynamic adaptability of the impurity treatment module 5. When the amount of wastewater is large, in order to reduce the storage pressure of the wastewater collection tank 4, multiple filter columns 502 can be activated simultaneously to increase the water outlet speed of the wastewater collection tank 4. When the amount of wastewater is small, a corresponding number of filter columns 502 can be selectively activated. On the one hand, this reduces energy consumption, and on the other hand, it is conducive to the rapid formation of agglomerates. It should be noted that there is a limit to the water inflow rate that can be tolerated by a single filter column 502, and the total water inflow rate is regulated by the pumping equipment.

[0037] The setting of the impurity treatment module 5 achieves a synergistic effect across the entire system, improving the effects of subsequent units:

[0038] Agglomeration (micrometer level) and molecular imprinting (nanoscale) form a multi-level interception network. Pollutant removal ranges from 1nm (small molecule flavonoids) to 500μm (colloidal particles). Cationic flocculants preferentially neutralize negatively charged colloids.

[0039] Verified by data:

[0040]

[0041] The molecular imprinting treatment unit 1 receives the wastewater output by the pretreatment unit, adopts the Fe3O4@SiO2 core-shell adsorption material with hesperidin as the template as the adsorbent, cooperates with the magnetic field fluidization effect, and performs targeted absorption of flavonoids in the wastewater, and cooperates with the magnet assistance and regeneration process to complete the recovery of flavonoids and regeneration of the adsorbent; in the Fe3O4@SiO2 core-shell adsorption material, the Fe3O4 magnetic core is ellipsoidal, the SiO2 shell thickness is 6.5-7.5nm, the mesopore diameter is 0.8-1.2nm, and the imprinting site density is 100%. .

[0042] The preparation method of Fe3O4@SiO2 core-shell adsorption material is as follows: Fe3O4 magnetic core is synthesized by co-precipitation method, and the Fe3O4 magnetic core is synthesized by regulating The molar ratio was 1:2.5, controlling its ellipsoidal morphology (major axis: 15±2 nm, minor axis: 5±1 nm). The mesoporous SiO2 shell was formed by hydrolysis of tetraethyl orthosilicate (TEOS), with a thickness of 7±0.5 nm and a pore size of 0.8–1.2 nm (matching the molecular size of hesperidin 1.12×0.82 nm). Surface imprinting was performed using 3-aminopropyltriethoxysilane (APTES) as the functional monomer, generating a density of Imprinted sites / cm² (quantified by BET and XPS).

[0043] The molecular imprinting treatment unit 1 includes an adsorption tank 101, which has an opening at the top and a porous plate water distributor 102 embedded and fixed below the opening. An adsorbent feeding port 103 is provided on the tank body between the top opening and the porous plate water distributor 102. An alternating magnetic field fluidization device is provided in the lower part of the adsorption tank 101 to keep the adsorbent in a rotating and fluidized state. A support layer 104 is provided in the adsorption tank 101, which is located within the magnetic field coverage of the alternating magnetic field fluidization device. The support layer 104 is composed of a conical porous sintered plate and is used to intercept the adsorbent. A drainage end and a backflush end are sequentially provided at the bottom of the adsorption tank 101. The water end is connected to the water inlet of the bioelectrochemical reaction unit 2 through a pipeline, and an ultraviolet sensor is provided at the drainage end for detecting the concentration of hesperidin in the discharged wastewater. The backflush end is connected to the output end of the backflush device. An adsorbent discharge portion is provided on the tank body above the support layer 104, and the discharge portion extends into the permanent magnetic separation device 7. The adsorbent is discharged by the backflush power, and the saturated adsorbent discharged from the adsorbent discharge portion is collected by the permanent magnetic separation device 7 and input into the desorption device 8. The saturated adsorbent is regenerated by the desorption device 8 and reused. A differential pressure transmitter is also provided at the support layer 104 for real-time monitoring of the pressure difference changes of the support layer 104.

[0044] The alternating magnetic field fluidization device includes an electromagnetic coil array 105, which is composed of 12 groups of annular coils. The 12 groups of annular coils are embedded in the outer tank wall of the adsorption tank 101 with the central axis of the adsorption tank 101 as the center ring and are arranged in a circular array. A non-uniform alternating magnetic field is formed by controlling the current injected into the electromagnetic coil array 105. A water cooling system is also provided in the electromagnetic coil array 105 to cool the electromagnetic coils.

[0045] The alternating magnetic field fluidization device is set up to use the Lorentz force to induce the adsorbent to rotate, avoid particle agglomeration, form a laminar flow state, and improve the adsorption effect.

[0046] The permanent magnetic separation device 7 includes a drum 701, the inner wall of the drum 701 is a permanent magnet part, and the outer wall is rotatably connected to the support seat 702. The outer wall of the drum 701 is inlaid with and fixedly connected to the external gear 703, and the outer wall of the support seat 702 is fixedly connected to the driving motor 704. The output end of the driving motor 704 is fixedly connected to the driving gear 705, and the tooth end of the driving gear 705 is engaged with the tooth end of the external gear 703. The drum 701 is driven to rotate along its axis by the driving motor 704. A separation conveying trough 706 is provided on the upper part of the drum 701. The separation conveying trough 706 is tilted. The upper wall of one end of the separation conveying trough 706 is in contact with the inner upper wall of the drum 701, and the outer wall of the other end is fixedly connected to the feed port of the desorption device 8. When the drum 701 rotates, the adsorbent magnetically attracted to the inner wall of the drum 701 is shoveled out by the upper wall of the separation conveying trough 706 and falls into the separation conveying trough 706. Under the action of gravity, the adsorbent flows into the desorption device 8 along the separation conveying trough 706.

[0047] The desorption liquid in the desorption device 8 is composed of ethanol: ammonia water = 4:1 (v / v), pH = 9.5, and the desorption efficiency can reach 92.3%.

[0048] At the same time, the conditions for the permanent magnetic separation device 7 to be turned on are:

[0049] Differential pressure transmitter ΔP≥0.12MPa; automatic backflush pulse discharge every 30 minutes; effluent hesperidin concentration>5mg / L.

[0050] After the treatment of molecular imprinting treatment unit 1, it is compared with traditional activated carbon adsorption:

[0051]

[0052] Bioelectrochemical reaction unit 2, which uses graphene aerogel loaded with electroactive bacteria as the anode and carbon fiber cloth loaded with Fe / N co-doped carbon quantum dots as the cathode. The graphene aerogel surface is modified with carboxylated carbon quantum dots, with a specific surface area of ≥1500m² / g and a pore size distribution including 0.8-2nm micropores and 5-10nm mesopores. The micropores are used to adsorb small molecular pollutants, and the mesopores are used to promote bacterial colonization. The wastewater is output from the molecular imprinting treatment unit 1 and enters the bioelectrochemical reaction unit 2. After the organic pollutants in the wastewater are removed by the oxidation reaction at the anode, a reduction reaction occurs at the cathode to generate H2O2;

[0053] The bioelectrochemical reaction unit 2 includes a reaction tank 201, in which an ion exchange membrane 202 is provided. The ion exchange membrane 202 is made of sulfonated polyetheretherketone and divides the inner cavity of the reaction tank 201 into an anode chamber 203 and a cathode chamber 204. The anode is arranged in the anode chamber 203, and a baffle assembly 205 is also provided in the anode chamber 203 to form an S-shaped flow channel. The cathode is arranged in the cathode chamber 204. The wastewater discharged from the molecular imprinting treatment unit 1 enters the anode chamber 203, and after the organic pollutants in the wastewater are removed by the oxidation reaction, it is injected into the microalgae photocatalytic coupling unit 3 by the suction equipment. At the same time, the H+ generated by the oxidation reaction migrates to the cathode chamber 204 through the ion exchange membrane 202 to undergo an oxygen reduction reaction.

[0054] Comparison between bioelectrochemical reaction unit 2 and traditional activated sludge process:

[0055]

[0056] The wastewater discharged from the bioelectrochemical reaction unit 2 enters the microalgae photocatalytic coupling unit 3. The microalgae photocatalytic coupling unit 3 includes a photobiofilm carrier 301. The base of the photobiofilm carrier 301 is a carbon fiber woven cloth, with a TiO2 nanowire array densely arranged below and a double algae symbiotic membrane arranged above, which is used to absorb small molecular organic matter in the wastewater. The H2O2 generated by the cathode is input into the TiO2 nanowire array through the guide tube, and the reaction generates OH to degrade the difficult-to-degrade organic matter in the wastewater.

[0057] The microalgae photocatalytic coupling unit 3 includes a photobioreactor 302, which is made of a translucent polymethyl methacrylate material. The photobiofilm carrier 301 is arranged inside the photobioreactor 302. The outer wall of the photobioreactor 302 located at the double algae symbiotic membrane is surrounded by a full-spectrum LED array 303, and the outer wall of the photobioreactor 302 located at the TiO2 nanowire array is surrounded by an ultraviolet LED array 304.

[0058] Among them, the porosity of carbon fiber woven cloth is 85%, the specific surface area is 320m² / m³, and the TiO2 nanowire array is grown by hydrothermal method with a length of 1.2±0.3μm, a diameter of 25±5nm, and a vertical arrangement density of roots / cm²,

[0059] The algae species ratio is 65:35 between Chlorella and Scenedesmus to improve system stability.

[0060] By actually running:

[0061]

[0062] At the same time, the H2O2 utilization rate reached 92%.

[0063] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A Citrus aurantium pharmaceutical wastewater treatment system, characterized in that: include: A pretreatment unit, wherein wastewater enters the pretreatment unit, colloidal proteins in the wastewater are removed by flocculation, and the generated flocculated impurities are formed into agglomerates, and the impurities in the wastewater are filtered by the agglomerates; the pretreatment unit comprises a wastewater collection tank (4), wastewater in the pharmaceutical process is discharged into the wastewater collection tank (4) for centralized storage, an impurity treatment module (5) is provided on one side of the wastewater collection tank (4), the impurity treatment module (5) comprises a base (501), a plurality of filter columns (502) are embedded in and fixedly connected to the upper part of the base (501), a flocculation treatment chamber (6) is fixedly connected to one side of the base (501), the interior of the flocculation treatment chamber (6) is divided into an inner flocculation accumulation chamber (601) and an outer water filtration chamber (602), wherein the interior of the flocculation accumulation chamber (601) is connected to the sewage outlet of the filter column (502), and a piston (603) is provided in the flocculation accumulation chamber (601), A driving device is provided at one end of the flocculent accumulation chamber (601) for driving the piston (603) to move in the flocculent accumulation chamber (601). The other end is an opening structure, and a plurality of limiting rods (604) are fixedly connected to the outer wall of the opening. The ends of the plurality of limiting rods (604) are fixedly connected to the limiting plate (605). A sealing cover (606) is sleeved on the outer wall of the limiting rod (604) and slidably connected. A sealing cover (606) is provided between the sealing cover (606) and the limiting plate (605). The water filter chamber (602) is connected via a spring (607), and the sealing cover (606) is embedded in the opening of the flocculent accumulation chamber (601) and sealed by the elastic force of the spring (607). The water filter chamber (602) is opened on the outside of the opening of the flocculent accumulation chamber (601). The water filter chamber (602) is connected to the flocculent accumulation chamber (601), and a second filter screen (608) is provided at the connection point between the two. The drainage outlet of the water filter chamber (602) is extended to the wastewater collection tank (4) through a pipeline. The molecular imprinting treatment unit (1) receives the wastewater outputted by the pretreatment unit, adopts Fe3O4@SiO2 core-shell adsorption material with hesperidin as template as adsorbent, cooperates with magnetic field fluidization, conducts targeted absorption of flavonoids in the wastewater, and cooperates with magnet assistance and regeneration process to complete the recovery of flavonoids and regeneration of adsorbent; The bioelectrochemical reaction unit (2) uses a graphene aerogel loaded with electroactive bacteria as an anode and a carbon fiber cloth loaded with Fe / N co-doped carbon quantum dots as a cathode. The surface of the graphene aerogel is modified with carboxylated carbon quantum dots, with a specific surface area of ≥1500 m² / g and a pore size distribution including 0.8-2 nm micropores and 5-10 nm mesopores. The micropores are used to adsorb small molecular pollutants and the mesopores are used to promote bacterial colonization. The wastewater is output from the molecular imprinting treatment unit (1) and enters the bioelectrochemical reaction unit (2). After the organic pollutants in the wastewater are removed by an oxidation reaction at the anode, a reduction reaction occurs at the cathode to generate H2O2. The microalgae photocatalytic coupling unit (3) is configured such that wastewater discharged from the bioelectrochemical reaction unit (2) enters the microalgae photocatalytic coupling unit (3). The microalgae photocatalytic coupling unit (3) comprises a photobiofilm carrier (301). The substrate of the photobiofilm carrier (301) is a carbon fiber woven cloth, a TiO2 nanowire array is densely arranged below the carrier, and a double algae symbiotic membrane is arranged above the carrier for absorbing small molecular organic matter in the wastewater. H2O2 generated by the cathode is input into the TiO2 nanowire array through a flow guide tube, and the reaction generates ·OH to degrade the refractory organic matter in the wastewater.

2. A Citrus aurantium pharmaceutical wastewater treatment system according to claim 1, characterized in that: The water inlets at the bottom of the plurality of filter columns (502) are connected in parallel and are connected to the interior of the wastewater collection pool (4) through a pumping device. A valve is independently provided at the water inlet of each filter column (502). A stirring device is provided at the center of the filter column (502) and a flocculant inlet is provided at the top. The flocculant is a cationic flocculant. The stirring device stirs and mixes the wastewater and the flocculant in the filter column (502). The upper part of the filter column (502) is covered and fixed with a filter screen 1 (503). A water outlet is provided above the filter screen 1 (503). The water outlets of the plurality of filter columns (502) are connected in parallel. The filtered wastewater flows into the molecular imprinting treatment unit through the parallel connection of the water outlets. Element (1), the filter column (502) is provided with a sewage outlet at the lower middle part, and an independent valve is provided at the sewage outlet. When the driving device pushes the piston (603) to move toward the opening of the flocculent accumulation chamber (601), the wastewater in the flocculent accumulation chamber (601) is filtered by the second filter screen (608) under the action of air pressure and then flows back into the wastewater collection tank (4) through the pipeline. At the same time, the flocculent impurities in the flocculent accumulation chamber (601) are compressed to discharge water and are located between the sealing cover (606) and the piston (603). When the thrust of the driving device exceeds the elastic threshold of the spring (607), the sealing cover (606) is separated from the opening of the flocculent accumulation chamber (601), and the flocculent impurities are squeezed out to the outside.

3. A Citrus aurantium pharmaceutical wastewater treatment system according to claim 1, characterized in that: The molecular imprinting treatment unit (1) includes an adsorption tank (101), the top of the adsorption tank (101) is open, and a porous plate type water distributor (102) is embedded and fixed below the opening, an adsorbent feeding port (103) is provided on the tank body between the top opening and the porous plate type water distributor (102), an alternating magnetic field fluidization device is provided in the lower part of the adsorption tank (101), which is used to keep the adsorbent in a rotating and fluidized state, a support layer (104) is provided in the adsorption tank (101), which is located within the magnetic field coverage of the alternating magnetic field fluidization device, the support layer (104) is composed of a conical porous sintered plate, which is used to intercept the adsorbent, and the bottom of the adsorption tank (101) is provided with A drainage end and a backflush end are provided. The drainage end is connected to the water inlet of the bioelectrochemical reaction unit (2) through a pipeline, and an ultraviolet sensor is provided at the drainage end for detecting the concentration of hesperidin in the discharged wastewater. The backflush end is connected to the output end of the backflush device. An adsorbent discharge portion is provided on the tank body above the support layer (104). The discharge portion extends into the permanent magnetic separation device (7). The saturated adsorbent discharged from the adsorbent discharge portion is collected by the permanent magnetic separation device (7) and input into the desorption device (8). The saturated adsorbent is regenerated by the desorption device (8) and reused. A differential pressure transmitter is also provided at the support layer (104) for real-time monitoring of the differential pressure change of the support layer (104).

4. A Citrus aurantium pharmaceutical wastewater treatment system according to claim 3, characterized in that: In the Fe3O4@SiO2 core-shell adsorption material, the Fe3O4 magnetic core is ellipsoidal, the SiO2 shell thickness is 6.5-7.5nm, the mesopore diameter is 0.8-1.2nm, and the imprinting site density is ≥3.2×10 15 sites / cm².

5. The system for treating wastewater from pharmaceutical production of Citrus aurantium according to claim 3, characterized in that: The alternating magnetic field fluidization device includes an electromagnetic coil array (105), which is composed of 12 groups of annular coils. The 12 groups of annular coils are embedded in the outer tank wall of the adsorption tank (101) with the central axis of the adsorption tank (101) as the center ring and are arranged in an annular array. A non-uniform alternating magnetic field is formed by controlling the current injected into the electromagnetic coil array (105). A water cooling system is also provided in the electromagnetic coil array (105) for cooling the electromagnetic coils.

6. A Citrus aurantium pharmaceutical wastewater treatment system according to claim 3, characterized in that: The permanent magnetic separation device (7) comprises a roller (701), the inner wall of the roller (701) is a permanent magnetic part, and the outer wall is rotatably connected to the support base (702), the outer wall of the roller (701) is inlaid with and fixedly connected to an external gear (703), the outer wall of the support base (702) is fixedly connected to a driving motor (704), the output end of the driving motor (704) is fixedly connected to a driving gear (705), the tooth end of the driving gear (705) is meshed with the tooth end of the external gear (703), and the roller (701) is driven along its axis by the driving motor (704). The roller (701) is rotated linearly, and a separation conveying trough (706) is provided on the upper part of the roller (701). The separation conveying trough (706) is placed obliquely, and the upper wall of one end of the separation conveying trough (706) is in contact with the inner upper wall of the roller (701), and the outer wall of the other end is fixedly connected to the feed port of the desorption device (8). When the roller (701) rotates, the adsorbent magnetically attracted to the inner wall of the roller (701) is shoveled out by the upper wall of the separation conveying trough (706) and falls into the separation conveying trough (706). Under the action of gravity, the adsorbent flows into the desorption device (8) along the separation conveying trough (706).

7. The system for treating wastewater from pharmaceutical production of Citrus aurantium according to claim 1, characterized in that: The bioelectrochemical reaction unit (2) comprises a reaction pool (201), wherein an ion exchange membrane (202) is provided in the reaction pool (201), wherein the ion exchange membrane (202) is made of sulfonated polyetheretherketone, and the inner cavity of the reaction pool (201) is divided into an anode chamber (203) and a cathode chamber (204), wherein the anode is provided in the anode chamber (203), and a baffle assembly (205) is further provided in the anode chamber (203) to form an S-shaped flow channel, and the cathode is provided in the cathode chamber (204), and the wastewater discharged from the molecular imprinting treatment unit (1) enters the anode chamber (203), and after the organic pollutants in the wastewater are removed by oxidation reaction, the wastewater is injected into the microalgae photocatalytic coupling unit (3) by a suction device, and at the same time, H generated by the oxidation reaction is + It migrates through the ion exchange membrane (202) to the cathode chamber (204) to undergo oxygen reduction reaction.

8. The Citrus aurantium pharmaceutical wastewater treatment system according to claim 1, characterized in that: The microalgae photocatalytic coupling unit (3) comprises a photobioreactor (302), wherein the photobioreactor (302) is made of a light-transmitting polymethyl methacrylate material, a photobiofilm carrier (301) is arranged inside the photobioreactor (302), a full-spectrum LED array (303) is arranged around the outer wall of the photobioreactor (302) located at the double algae symbiotic membrane, and a UV LED array (304) is arranged around the outer wall of the photobioreactor (302) located at the TiO2 nanowire array.

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