Nano adsorbent online recovery adsorption-membrane separation device for deep treatment of printing and dyeing wastewater

Abstract

The invention discloses a nano adsorbent online recovery adsorption-membrane separation device for deep treatment of printing and dyeing wastewater. According to the device, a water inlet pump, a blast aeration pipe, micropore aeration discs arranged on the two sides of the blast aeration pipe in pairs, a flat sheet membrane assembly, a penetrating fluid suction main pipe, a pressure meter, a suction pump and a time controller are integrated in a single shell, and suction / aeration timing switching is achieved. A sludge collecting hopper and an inclined guide plate are arranged below the shell, and a backflow sludge outlet loop, a backflow water outlet loop and a sludge discharge port are arranged, so that an adsorbent is circularly enriched and returned between the reaction area and the sludge collecting hopper, loss is reduced, membrane pollution is inhibited, and the device is suitable for stable operation of standard discharge and reuse of printing and dyeing wastewater.

Description

Technical Field

[0001] This invention relates to the field of dyeing and printing wastewater treatment technology and equipment, and more particularly to an online recovery adsorption-membrane separation device for deep treatment of dyeing and printing wastewater using nano-adsorbents. Background Technology

[0002] Dyeing and printing wastewater is characterized by high concentrations of heavy metal ions, high color intensity, and strong water quality fluctuations. It also contains new pollutants with high ecotoxicity and hazard, such as perfluorinated and polyfluoroalkyl substances (PFAS). In recent years, nano-adsorbents, due to their large specific surface area, high surface energy, and abundant active sites, can effectively remove trace organic pollutants and recalcitrant components such as heavy metal ions from water within a very short residence time, making them an important research direction in the field of advanced treatment and resource recovery of dyeing and printing wastewater. Current processes typically involve directly adding nano-adsorbents to coagulation sedimentation tanks, bioreactors, or sand filtration units to ensure sufficient contact and rapid adsorption of pollutants. However, because nano-adsorbents are small in size and have a much higher surface atom ratio than bulk materials, they are prone to agglomeration into stable colloids or coupling with large organic molecules, thus losing their superior performance at the nanoscale. Furthermore, due to their small particle size, strong migration and diffusion, and strong binding ability, nano-adsorbents in the environment are difficult to separate and recover efficiently using traditional sedimentation, centrifugation, or sieving methods after adsorption. Under high-throughput operation conditions, these adsorbents are more likely to be lost with the effluent or accumulate in the system, resulting in increased costs, secondary pollution, and uncontrolled adsorbent usage.

[0003] To improve the recyclability of nano-adsorbents, some studies have attempted to use methods such as magnetization modification or immobilization on a support, or to add ultrafiltration, microfiltration, or even reverse osmosis units in subsequent processes for retention. However, magnetization modification often leads to the shielding of adsorption sites and a decrease in adsorption capacity; immobilization or support methods significantly reduce the specific surface area of ​​particles and mass transfer efficiency; while additional membrane separation units can capture free adsorbents, they are accompanied by a series of operational bottlenecks such as increased transmembrane pressure difference, concentration polarization, and membrane fouling. Furthermore, functions such as feed water, aeration, suction, and adsorbent recycling are mostly in the form of dispersed modules, resulting in increased land occupation and energy consumption, and cumbersome system maintenance.

[0004] Based on the above problems, there is an urgent need for an integrated adsorption-membrane separation reactor for removing pollutants from dyeing and printing wastewater. Summary of the Invention

[0005] The purpose of this invention is to solve the problems of difficult efficient recovery of nanoscale adsorbents in continuous flow systems, easy loss with effluent, easy membrane fouling after coupling with membrane units, and scattered operation control. The invention proposes an integrated adsorption-membrane separation reactor for removing pollutants from dyeing and printing wastewater.

[0006] Specifically, it is an integrated adsorption-membrane separation reactor for removing organic pollutants and heavy metal ions from dyeing and printing wastewater.

[0007] The device integrates water inlet, aeration and mixing, membrane separation, clear liquid suction and sludge collection and return units within a single reactor body shell, enabling the water-solid-gas three phases to fully contact and circulate under controlled conditions, achieving online enrichment and return of nano-adsorbents, while maintaining stable operation of the membrane module.

[0008] To achieve the above objectives, this invention provides a reactor that, on the one hand, fully leverages the rapid mass transfer advantages of nano-adsorbents and the selective retention characteristics of membrane separation; on the other hand, it enables online recovery and regeneration of the adsorbent. This device allows for controlled circulation of water, solid, and gas phases within the same reaction space, and by optimizing fluid distribution and shear conditions, effectively mitigates membrane fouling while ensuring efficient retention and directional transport of the nano-adsorbent within the device.

[0009] The reactor includes:

[0010] The reactor body has an inlet and pressurization unit at the bottom, a blower aeration system connected to the aeration pipe inside the shell, and microporous aeration discs arranged at equal intervals on the aeration pipe to form a turbulent suspension mixture of water and nano-adsorbent in a fine bubble manner. Flat plate membrane modules are arranged in parallel above the aeration pipe, and the membrane modules are supported by the support steps on the side wall of the shell. The permeate outlets of each membrane module are collected into the suction main pipe. The suction main pipe is equipped with a pressure detection and suction drive unit. After the suction / aeration cycle is switched by a time control switch, the clear liquid can be discharged.

[0011] An inclined guide plate is provided between the reactor body and the sludge collection hopper below, which is used to direct the sinking solids and adsorbent into the bottom of the sludge collection hopper.

[0012] The sludge hopper is vertically supported and equipped with two return branches: one is the sludge return branch, where the return sludge pump and return sludge pipe send the high solids content mixed liquor back to the aeration mixing area inside the shell; the other is the turbid liquid return branch, where the return water pump and return water pipe send the turbid liquid on the side of the sludge hopper back to the inlet water side of the membrane area to adjust the internal circulation volume and particle residence time.

[0013] The bottom of the sludge hopper is equipped with a sludge discharge port for intermittent or continuous discharge of enriched sludge and depleted adsorbent.

[0014] Without introducing rigid partitions, this invention creates functional areas from bottom to top within the reactor body shell through the spatial arrangement of components:

[0015] The lower part is the aeration and mixing zone, which is used to keep the nano-adsorbent suspended and enhance mass transfer; the middle part is the membrane separation zone, which is used to selectively retain the mixture containing the adsorbent.

[0016] The upper part is the clear liquid suction zone, used for stable suction and backwash control; the bottom and sludge collection hopper together form the sludge collection and return zone, realizing the online enrichment, return and discharge of adsorbent and solids.

[0017] In addition, each liquid pump and blower adopts frequency conversion control, and closed-loop regulation is performed based on the transmembrane pressure difference, dissolved oxygen or flow signal as feedback; microfiltration or ultrafiltration membranes can be selected for flat sheet membrane modules; a single main pipeline should be used on the suction side to collect the permeate of all membrane modules, simplifying the pipeline and facilitating centralized monitoring and control.

[0018] Compared with the prior art, the present invention integrates the sludge collection hopper and the dual reflux loop to construct a closed-loop management of the nano-adsorbent in the device, which significantly reduces adsorbent loss and reduces replenishment and operating costs.

[0019] In terms of gas-liquid interaction, the microporous aeration disc and the membrane module are set in the vertical direction respectively. The bubbles rise to both sides of the membrane to form uniform shear and disturbance, continuously cleaning the membrane surface and weakening concentration polarization, thereby inhibiting membrane fouling.

[0020] In addition, water intake, aeration, membrane separation, suction and reflux are all completed in a single housing, significantly reducing external units and pipelines, which not only reduces footprint and energy consumption, but also facilitates centralized monitoring and automated control.

[0021] Due to the synergistic effect of the above structures, the device significantly improves the removal efficiency of PFAS and heavy metal ions while maintaining stable operation, making it suitable for advanced treatment and reuse of dyeing and printing wastewater. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the adsorption-membrane separation reactor of the present invention.

[0023] Figure 2 This is a diagram of the experimental setup for an adsorption-membrane separation reactor.

[0024] Figure 3 The performance of the adsorption-membrane separation reactor during operation is: (a) normalized flux; (b) instantaneous membrane flux and transmembrane pressure difference.

[0025] Figure 4 This is a graph showing the removal performance of total chromium (TCr) by a membrane adsorption-separation reactor.

[0026] Figure 5 The boundary performance diagrams of the adsorption-membrane separation reactor under high concentration of nano-adsorbents are as follows: (a) normalized flux versus permeate volume; (b) instantaneous membrane flux versus transmembrane pressure difference.

[0027] Reference numerals: 1-Reactor body, 2-Inlet pipe, 3-Inlet water pump, 4-Blower, 5-Aeration pipe, 6-Microporous aeration disc, 7-Membrane module, 8-Suction main pipe, 9-Pressure gauge, 10-Outlet suction pump, 11-Time control switch, 12-Outlet pipe, 13-Supporting step, 14-Sludge hopper, 15-Support foot, 16-Inclined guide plate, 17-Return sludge pump, 18-Return sludge pipe, 19-Return water pump, 20-Return water pipe, 21-Sludge discharge port. Detailed Implementation

[0028] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0029] This invention provides an integrated adsorption-membrane separation reactor for removing pollutants from dyeing and printing wastewater, comprising:

[0030] Reactor body 1;

[0031] A water inlet pipe 2 is provided on one side of the bottom of the reactor body 1, and the water inlet pipe 2 is connected to the water inlet pump 3;

[0032] An aeration system is installed inside the reactor body 1. The aeration system includes an aeration pipe 5, which is connected to a blower 4. Multiple (at least 5 sets) microporous aeration discs 6 are arranged at intervals along the length of the pipe body of the aeration pipe 5. The microporous aeration discs 6 are respectively arranged on both sides of the aeration pipe 5 and are arranged in pairs with the central pipe of the aeration pipe 5 as the symmetrical line.

[0033] Eight flat sheet membrane modules 7 are arranged parallel above the aeration pipe 5, and the flat sheet membrane modules 7 are arranged at intervals along the length of the reactor body 1.

[0034] The permeate outlets at the top of all membrane modules 7 are connected to the suction main pipe 8 via pipes and converge through the middle outlet of the suction main pipe 8; the middle outlet of the suction main pipe 8 is connected in sequence to the pressure gauge 9 and the water suction pump 10 via pipes and the end of the pipe is connected to the water outlet pipe 12; the water suction pump 10 is connected to the time control switch 11.

[0035] The membrane module 7 is supported by the support steps 13, which are located on the side walls on both sides of the reactor body 1.

[0036] The present invention provides a specific implementation method as follows:

[0037] The sludge hopper 14 is located below the reactor body 1; the sludge hopper 14 is supported by support legs 15;

[0038] An inclined guide plate 16 is provided between the bottom of the sludge hopper 14 and the reactor body 1;

[0039] A return mud pipe 18 is provided at one end of the bottom of the mud hopper 14, and the return mud pipe 18 is connected to the return mud pump 17.

[0040] A return water pipe 20 is provided at the other end of the bottom of the sludge hopper 14. One end of the return water pipe 20 is connected to the return water pump 19, and the other end is connected to and returned to the other side of the bottom of the reactor body 1 opposite to the inlet pipe 2.

[0041] The mud collection hopper 14 is equipped with a mud discharge port 21 at the bottom.

[0042] The present invention provides a specific implementation method as follows:

[0043] The reactor body 1 is vertically divided into an aeration mixing zone, a membrane separation zone, and a clear liquid suction zone from bottom to top.

[0044] The aeration mixing zone is defined by the aeration pipe 5 and the microporous aeration discs 6 on both sides.

[0045] The membrane separation zone is defined by the membrane module 7 and the supporting step 13;

[0046] The clear liquid suction area is defined by the suction main pipe 8, pressure gauge 9, water suction pump 10, time control switch 11, and water outlet pipe 12.

[0047] The present invention provides a specific implementation method as follows:

[0048] The microporous aeration discs 6 are arranged vertically in correspondence with each membrane module 7;

[0049] The rising bubbles formed by the microporous aeration disc 6 can form a uniform shear flow on both sides of the membrane of each membrane module 7.

[0050] The present invention provides a specific implementation method as follows:

[0051] The time control switch 11 is used to control the start and stop cycle of the effluent suction pump 10 and to switch between suction and aeration modes at regular intervals.

[0052] The present invention provides a specific implementation method as follows:

[0053] The suction main pipe 8 is a single main pipe that connects in series to the permeate side outlets of all membrane modules 7;

[0054] The suction main pipe 8 is located at the upper part of the reactor body 1, the aeration pipe 5 and the microporous aeration disc 6 are located at the lower part of the reactor body 1, and the membrane module 7 is located in the middle of the reactor body 1.

[0055] The present invention provides a specific implementation method as follows:

[0056] The inclined guide plate 16 is arranged at an angle from the bottom of the reactor body 1 toward the bottom of the sludge hopper 14, and is used to introduce the settled solids and adsorbent into the sludge hopper 14.

[0057] The present invention provides a specific implementation method as follows:

[0058] The sludge return pump 17 is used to return the high solids content mixed liquid enriched in the sludge collection hopper 14 to the downstream of the aeration pipe 5 or the aeration mixing zone of the reactor body 1 via the sludge return pipe 18.

[0059] The return water pump 19 returns the liquid in the return water pipe 20 to the inlet water side of the membrane separation zone of the reactor body 1 to adjust the circulation volume and particle residence time.

[0060] The present invention provides a specific implementation method as follows:

[0061] The inlet pump 3, outlet pump 10, return mud pump 17 and return outlet pump 19 are frequency converters used to adjust the flow rate or pressure according to the operating load.

[0062] The present invention provides a specific implementation method as follows:

[0063] Blower 4 is a variable frequency blower used to adjust the aeration volume.

[0064] Example 1

[0065] like Figure 1 As shown, the present invention provides an adsorption-membrane separation reactor for online recovery of nano-adsorbents, comprising a reactor body 1, which is rectangular in shape. The reactor body 1 contains an inlet and pressurization unit, an aeration unit, a membrane separation and clear liquid suction unit, and a sludge collection and return unit located below the reactor body 1. The device sequentially forms an aeration mixing zone, a membrane separation zone, and a clear liquid suction zone from bottom to top.

[0066] The bottom of the reactor body 1 is shaped like a square pyramid. The bottom of the reactor body 1 shell is connected to the sludge collection hopper 14 below the inclined guide plate 16, together forming a sludge collection and recirculation zone. The units are arranged continuously in space and cooperate with each other in function to realize the online retention, enrichment and recycling of nano-adsorbents, and maintain the stable operation of the membrane module 7.

[0067] The water inlet and pressurization unit of reactor body 1 is located in the lower part of reactor body 1. The water inlet pipe 2 is connected to the water inlet pump 3 to send raw water into reactor body 1. In the blower-aeration unit, the blower 4 is connected to the aeration pipe 5 inside the shell. The aeration pipe 5 is arranged along the length of the shell, and microporous aeration discs 6 are symmetrically arranged on both sides of the aeration pipe 5 to form a gas-liquid contact interface with uniformly distributed fine bubbles. The nano-adsorbent is continuously stirred and kept suspended in this area, so as to fully contact the pollutants in the incoming water, while providing uniform and controllable bottom shear conditions for the membrane separation zone above.

[0068] The membrane separation and supernatant suction unit is arranged on the aeration pipe 5. Eight flat sheet membrane modules 7 are arranged in parallel. The bottoms of both ends of the flat sheet membrane modules 7 are supported by support steps 13 set on the inner side walls of both ends of the reactor body 1. The permeate outlets at the top of the flat sheet membrane modules 7 are all collected into a single suction main pipe 8. A pressure gauge 9 and an effluent suction pump 10 are connected in series on the suction main pipe 8, and a time control switch 11 is configured to perform periodic suction operations to suppress membrane deposition and concentration polarization. The supernatant is discharged through the effluent pipe 12.

[0069] The above arrangement allows the bubble flow formed from bottom to top to generate uniform shear and disturbance on both sides of the membrane, thereby achieving both online membrane cleaning and flux stability without adding additional components.

[0070] An inclined guide plate 16 is installed between the bottom of the shell and the sludge collection hopper 14 below. During operation, the adsorbent and solid particles are directionally collected into the sludge collection hopper 14 by the inclined guide plate 16 during the turbulent-sedimentation process in the lower part of the reactor body 1 shell. The sludge collection hopper 14 is fixed to the bottom of the reactor body 1 shell by four support legs 15 and is equipped with two independent return loops: one is a sludge return loop, including a sludge pump 17 and a sludge pipe 18, used to return the high solids content mixture at the bottom of the sludge collection hopper 14 to the aeration mixing zone inside the reactor body 1 shell to maintain the effective concentration of adsorbent and particle residence time in the system; the other is a turbid liquid return loop, including a return water pump 19 and a return water pipe 20, used to return the supernatant on one side of the sludge collection hopper 14 to the inlet water side of the membrane zone to balance water fluctuations and improve the internal circulation hydraulic conditions. A sludge discharge port 21 is provided at the bottom of the sludge collection hopper 14 for intermittent or continuous discharge of enriched sludge or exhausted adsorbent, facilitating subsequent regeneration or proper disposal.

[0071] The specific steps of the method for treating dyeing and printing wastewater using the above-mentioned membrane adsorption separation reactor are as follows:

[0072] Dyeing and printing wastewater is continuously fed into the reactor body 1 shell, and the dosage of nano-adsorbent is adjusted according to the pollutant concentration. Blower 4 and aeration pipe are turned on to form a fine bubble turbulent aeration mixing zone below membrane module 7. The effluent suction pump 10 is turned on to maintain stable suction in the membrane separation zone, and the suction is started and stopped at preset intervals by time control switch 11. At the same time, according to the enrichment of solids in the device, sludge return pipe 18 is turned on to return the high solids mixed liquid to the aeration mixing zone. The return ratio of turbid liquid return pipe 20 is adjusted according to the influent water quality and load changes. When the solids in sludge hopper 14 accumulate to a set height, sludge discharge port 21 is turned on for discharge to maintain the material balance and long-term stable operation of the device. In this method, rigid baffles are not required inside the reactor. The arrangement of the membrane modules corresponds to the aeration mixing zone formed by the aeration pipes and microporous aeration discs below. Combined with the bottom inclined guide plate and sludge collection hopper structure, functional areas such as aeration mixing zone, membrane separation zone and sludge collection zone are naturally formed inside the reactor. This reduces the number of internal components and facilitates inspection and maintenance while ensuring process integration.

[0073] Optionally, the membrane module 7 can adopt a flat-plate structure of microfiltration or ultrafiltration membrane. The reactor body 1 shell and piping can be made of corrosion-resistant polyvinylidene fluoride (PVDF) depending on the corrosiveness of the treated medium. The suction main pipe 8 should preferably adopt a single-pipe collection method for centralized monitoring and control. The array of aeration pipes 5 and microporous aeration discs 6 can be arranged in zones, and the air volume distribution in different zones can be achieved through valve cooperation. A return pump is correspondingly set on the return sludge pipe 18 and the return water pipe 20. The return pump, the effluent suction pump, and the blower are all connected to a time controller. The time controller is used to automatically switch between suction and aeration modes according to a preset cycle, so that the reactor works in a "run-stop-run" cycle mode: during the suction phase, the effluent suction pump is started for intermittent suction, and during the aeration phase, the blower aeration is maintained or enhanced to achieve membrane surface scouring and mixed liquor renewal. Preferably, the suction phase lasts for 7-9 minutes, the stop phase lasts for 1-3 minutes, and the cycle is 8-12 minutes, thereby maintaining stable suction while reducing concentration polarization and membrane fouling. Furthermore, the preferred operating flux during the suction phase is 15-30 L / (m³). 2 • h), the transmembrane pressure difference is preferably controlled within the range of 10-30 kPa to balance the output water volume and operational stability.

[0074] Example 2

[0075] This embodiment improves upon Embodiment 1 by modularizing its functionality to verify the removal performance of the membrane adsorption separation reactor for Cr(VI), a typical heavy metal ion, in dyeing and printing wastewater. The experimental principle of this scheme is the same as that of Embodiment 1, except that the device is changed from an integrated structure to a modular combination that can be controlled independently, facilitating the testing and adjustment of operating parameters.

[0076] Experimental setup such as Figure 2 As shown, it includes a feed tank, a peristaltic pump, a magnetic stirrer, a membrane adsorption separation reactor, a pressure monitor, a water collection tank, an electronic balance, and a real-time data recording system for flux and transmembrane pressure difference (TMP).

[0077] Experimental conditions: The water supply simulated dyeing and printing wastewater, the reaction volume was 750 mL, the pH was adjusted to 3.0 to conform to the characteristics of acidic dyeing and printing wastewater, and the dosage of nano-adsorbent was 1.0 g / L.

[0078] To maintain a constant adsorbent concentration and Cr(VI) concentration within the reactor, a peristaltic pump continuously replenishes the Cr(VI) solution from the feed tank. A magnetic rotor is installed at the bottom of the reactor, working in conjunction with an external magnetic stirrer to simulate the hydraulic disturbances generated on the membrane module by aeration pipe 5 in Example 1. A negative pressure environment is established by the peristaltic pump to achieve continuous sampling of the permeate. A pressure gauge and the peristaltic pump are connected in series in the suction line to monitor TMP and maintain steady-state suction. Permeate flows through the outlet pipe into a collection tank placed on an electronic balance, and a data acquisition system connected to the balance and pressure gauge synchronously records flux and pressure changes.

[0079] Experimental results are as follows Figure 3 As shown: The membrane adsorption separation reactor filtered a cumulative total of 300 mL of water sample over 5 hours. With increasing filtration volume, the normalized flux (J / J0) remained stable, with an average specific flux of 0.999 and an average permeate flux of 21.72 L / (m²). 2 •h). TMP remained stable at 2.39 kPa. Influent and effluent water quality results are as follows: Figure 4 As shown, the influent total chromium (TCr) concentration was 24.06 mg / L, the effluent TCr concentration was 0.10 mg / L, and the removal rate reached 99.58%.

[0080] The results show that the modular reactor can effectively suppress membrane fouling caused by nano-adsorbents while meeting the actual operating flux requirements, and exhibits excellent Cr(VI) removal performance.

[0081] Example 3

[0082] The reactor device used in this embodiment is the same as that in Embodiment 2, and is mainly used to study the operational stability and load-bearing limit of the membrane adsorption separation reactor under high concentration of nano-adsorbent conditions.

[0083] The experimental conditions were as follows: the feed water was deionized water, and the reaction volume was 40 mL. The initial concentration of the nano-adsorbent was 40 g / L (total 1.6 g), and then the concentration was increased by 20 g / L every 1 h until the adsorbent concentration in the system reached 500 g / L (total 20.0 g).

[0084] like Figure 5As shown in Table 1, the effect of continuously increasing adsorbent concentration on reactor operating performance can be divided into three stages:

[0085] (1) Stabilization period. When the adsorbent concentration is below 200 g / L (total dosage ≤ 8.0 g), the reactor flux and TMP are basically stable. The average flux is 44.51 L / (m²). 2 •h), average TMP 13.13 kPa.

[0086] (2) Fluctuation period. When the adsorbent concentration is 200-400 mg / L (total dosage 8.0-16.0 g), the specific flux decreases slowly, while the total flux (TMP) increases with adsorbent dosage. The average flux is 42.83 L / (m²). 2 •h), average TMP 15.63 kPa.

[0087] (3) Breakthrough period. At an adsorbent concentration of 400 g / L (total dosage 16.0 g), TMP rapidly increased, reaching 30.7 kPa at the maximum adsorbent concentration, corresponding to a drop in normalized flux to 0.814. The average flux was 39.18 L / (m²). 2 •h), average TMP 24.92 kPa.

[0088] Experimental results show that the membrane adsorption separation reactor can maintain stable filtration performance under high concentration of nano-adsorbent (≤ 200 g / L), without significant membrane clogging or flux decline. However, as the adsorbent concentration further increases, a significant increase in transmembrane pressure difference occurs. These results provide crucial information for the engineering scale-up, parameter tuning, and upper limit control of adsorbent dosage.

[0089] Table 1. Effect of adsorbent dosage on the filtration performance of the membrane adsorption separation reactor

[0090] .

Claims

1. An online recovery adsorption-membrane separation device for nano-adsorbents in the deep treatment of dyeing and printing wastewater, characterized in that, include: Reactor body (1); A water inlet pipe (2) is provided on one side of the bottom of the reactor body (1), and the water inlet pipe (2) is connected to the water inlet pump (3); An aeration system is installed inside the reactor body (1). The aeration system includes an aeration pipe (5), which is connected to a blower (4). Multiple sets of microporous aeration discs (6) are arranged at intervals along the length of the aeration pipe (5) on both sides of the pipe body. The microporous aeration discs (6) are arranged in pairs with the center line of the aeration pipe (5) as the symmetrical line. At least 8 flat membrane modules are arranged in parallel above the aeration pipe (5). The permeate outlets at the top of all membrane modules (7) are connected to the suction main pipe (8) through pipes and converge through the middle outlet of the suction main pipe (8); the middle outlet of the suction main pipe (8) is connected to the pressure gauge (9) and the water suction pump (10) in sequence through pipes and the end of the pipe is connected to the water outlet pipe (12); the water suction pump (10) is connected to the time control switch (11). The membrane module (7) is supported by a support step (13), which is set on the side walls on both sides of the reactor body (1).

2. The apparatus according to claim 1, characterized in that, The sludge hopper (14) is located below the reactor body (1); the sludge hopper (14) is supported by support legs (15); An inclined guide plate (16) is provided between the bottom of the sludge collection hopper (14) and the reactor body (1). The bottom end of the sludge collection hopper (14) is provided with a return sludge pipe (18), which is connected to the return sludge pump (17); The other end of the bottom of the sludge collection hopper (14) is provided with a return water pipe (20). One end of the return water pipe (20) is connected to the return water pump (19), and the other end is connected to and sent back to the other side of the bottom of the reactor body (1) opposite to the inlet pipe (2). The mud collection hopper (14) is provided with a mud discharge port (21) at the bottom.

3. The apparatus according to claim 1 or 2, characterized in that, The reactor body (1) is vertically arranged from bottom to top into an aeration mixing zone, a membrane separation zone, and a clear liquid suction zone. The aeration mixing zone is defined by the aeration pipe (5) and the microporous aeration discs (6) on both sides; The membrane separation zone is defined by the membrane module (7) and the supporting steps (13); The clear liquid suction area is defined by the suction main pipe (8), pressure gauge (9), water suction pump (10), time control switch (11), and water outlet pipe (12).

4. The apparatus according to claim 1, characterized in that, The microporous aeration disc (6) is arranged vertically in correspondence with each membrane module (7). The rising bubbles formed by the microporous aeration disc (6) can form a uniform shear flow on both sides of the membrane of each membrane module (7).

5. The apparatus according to claim 1, characterized in that, The time control switch (11) is used to control the start and stop cycle of the effluent suction pump (10) and to switch between suction and aeration modes at regular intervals.

6. The apparatus according to claim 1, characterized in that, The suction main pipe (8) is a single main pipe that connects in series to the permeate side outlets of all membrane modules (7); The suction main pipe (8) is located at the upper part of the reactor body (1), the aeration pipe (5) and the microporous aeration disc (6) are set at the lower part of the reactor body (1), and the membrane module (7) is set in the middle of the reactor body (1).

7. The apparatus according to claim 2, characterized in that, The inclined guide plate (16) is arranged at an angle from the bottom of the reactor body (1) toward the bottom of the sludge hopper (14) to introduce the settled solids and adsorbent into the sludge hopper (14).

8. The apparatus according to claim 2, characterized in that, The reflux sludge pump (17) is used to return the high solids content mixed liquid enriched in the sludge collection hopper (14) to the downstream of the aeration pipe (5) or the aeration mixing zone of the reactor body (1) via the reflux sludge pipe (18). The reflux pump (19) sends the liquid in the reflux pipe (20) back to the inlet water side of the membrane separation zone of the reactor body (1) to adjust the circulation volume and particle residence time. The inlet pump (3), outlet pump (10), sludge return pump (17) and outlet pump (19) are variable frequency drives used to adjust the flow rate or pressure according to the operating load.

9. The apparatus according to claim 1, characterized in that, The blower (4) is a variable frequency blower used to adjust the aeration volume.

10. A method of using the apparatus according to any one of claims 1-9, characterized in that, When the reactor is running, nano-sized adsorbent is added and circulated and recycled online through the loop formed by the return mud pipe (18) and the return water pipe (20).

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