System and process for removing micro-plastic composite perfluorinated pollutants in wastewater

Abstract

The invention relates to a system and a process for removing micro-plastic composite perfluorinated pollutants in wastewater, the system is used for removing the micro-plastic composite perfluorinated pollutants in the wastewater, the system comprises: a reduction irradiation unit for performing reduction and irradiation treatment on the wastewater containing the micro-plastic composite perfluorinated pollutants to obtain primary purified water; the oxidation irradiation unit is connected with the reduction irradiation unit and is used for carrying out oxidation and secondary irradiation treatment on the primary purified water to obtain secondary purified water; and the purified water collecting unit is connected with the oxidation irradiation unit and is used for collecting secondary purified water. Compared with the prior art, the micro-plastic composite perfluorinated pollutants in the wastewater can be removed, the wastewater can be purified, the perfluorinated pollutants in a water body can be completely removed, oxidative degradation of micro-plastic can be effectively promoted, the micro-plastic composite perfluorinated pollutant treatment capacity is more excellent, and the treatment effect is better. The perfluorinated pollutants in a high-concentration range can be treated, and the influence degree of the treatment efficiency by an environmental matrix is relatively small.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and in particular to a system and process for removing microplastic-containing composite perfluorinated pollutants in wastewater. Background Art

[0002] Since their production, perfluorinated chemicals (PFAS) and plastic products have been widely used in various industries, including the textile industry, papermaking, electroplating industry, and automobile manufacturing. PFAS and microplastics are stable in nature and extremely persistent in the environment. They are one of the most difficult organic pollutants to decompose. Microplastics are also very easy to combine with PFAS in the environment to form microplastic-complex perfluorinated pollutants. A large number of studies have shown that microplastic-complex perfluorinated pollutants are almost impossible to degrade by conventional means. In recent years, microplastic-complex perfluorinated pollutants have been detected in large quantities in the environment, attracting widespread attention from society and academia. Microplastic-complex perfluorinated pollutants are characterized by biological toxicity, environmental persistence, and bioaccumulation. They pose significant environmental and health risks and have been proven to be directly related to damage to human health.

[0003] However, there are currently no practical and effective measures for wastewater containing microplastics and perfluorinated pollutants, and conventional pollutant treatment methods are not suitable for the degradation treatment of wastewater containing microplastics and perfluorinated pollutants. Traditional oxidation processes (such as biological oxidation) may achieve the removal of single organic pollutants, but they can hardly produce a bond-breaking effect on PFAS and microplastics, and it is difficult to achieve the removal of microplastics and perfluorinated pollutants. Conventional wastewater treatment plants are almost unable to achieve degradation and removal of wastewater containing microplastics and perfluorinated pollutants. Microorganisms can only decompose microplastics and perfluorinated pollutants into more toxic and persistent short-chain pollutants. Therefore, the development of special treatment technologies for wastewater containing microplastics and perfluorinated pollutants is a major challenge in the current field of environmental science research.

[0004] Patent publication number CN220149323U discloses a device for removing perfluorinated pollutants from water. The device comprises a solar collector, a membrane distillation unit, and a photoreduction treatment unit. The solar collector is used to heat a water sample containing perfluorinated pollutants. The membrane distillation unit, connected to the solar collector, concentrates the heated water sample by membrane distillation. The photoreduction treatment unit includes a degradation tank and a UV lamp, the degradation tank being connected to the concentrated liquid outlet of the membrane distillation unit. However, this device only removes perfluorinated pollutants and cannot effectively promote the oxidative degradation of microplastics. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a system and process for removing microplastics and perfluorinated pollutants in wastewater, so as to achieve the removal of microplastics and perfluorinated pollutants in wastewater and the purification of wastewater. It can not only achieve the complete removal of perfluorinated pollutants in water bodies, but also effectively promote the oxidative degradation of microplastics, have better perfluorinated pollutant treatment capabilities, can treat perfluorinated pollutants in a high concentration range, and the treatment efficiency is less affected by the environmental matrix.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] In one aspect, the present invention provides a system for removing microplastics and perfluorinated pollutants in wastewater, which is used to remove microplastics and perfluorinated pollutants in wastewater. The system comprises:

[0008] The reduction and irradiation unit reduces and irradiates wastewater containing microplastics and perfluorinated pollutants to obtain primary purified water;

[0009] an oxidizing irradiation unit connected to the reducing irradiation unit, performing oxidation and secondary irradiation treatment on the primary purified water to obtain secondary purified water;

[0010] and a purified water collecting unit connected to the oxidation irradiation unit and used for collecting secondary purified water.

[0011] Furthermore, the microplastics composite perfluorinated pollutants include perfluorinated pollutants and microplastics;

[0012] The perfluorinated pollutants include perfluorinated carboxylic acids (PFCAs), perfluorinated sulfonic acids (PFSAs), perfluorinated sulfonates (PFASs) or perfluorinated telomers;

[0013] The microplastics include polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), polyurethane (PU), polyethylene terephthalate (PET) or polylactic acid (PLA);

[0014] The perfluorinated pollutant concentration is 4×10 -5 ~200mg / L, preferably 0.0001~150mg / L;

[0015] The concentration of the microplastics is 0.00001 to 5 g / L, preferably 0.001 to 2 g / L.

[0016] Furthermore, the reduction irradiation unit includes:

[0017] a first cylinder;

[0018] A first liquid inlet provided on the first cylinder and used for the inflow of wastewater containing microplastics and perfluorinated pollutants;

[0019] a first liquid outlet provided on the first cylinder and used for primary purified water to flow out;

[0020] a reducing agent input port provided on the top of the first cylinder and used for inputting the reducing agent;

[0021] and a first irradiation device arranged at the top of the first cylinder and used for irradiation.

[0022] Furthermore, the irradiation dose of the first irradiation device is 100 to 1000 kGy, preferably 200 to 500 kGy;

[0023] The radiation source of the first irradiation device includes a low- to medium-energy electron beam radiation source, a high-energy electron beam radiation source, or a gamma-ray radiation source.

[0024] Furthermore, a first flow controller is provided on the pipeline connected to the first liquid inlet for controlling the inlet flow rate of the wastewater containing microplastics and perfluorinated pollutants.

[0025] Furthermore, the oxidation irradiation unit includes:

[0026] a second cylinder;

[0027] a second liquid inlet provided on the second cylinder and used for the primary purified water to flow in;

[0028] a second liquid outlet provided on the second cylinder and used for the secondary purified water to flow out;

[0029] an oxidant inlet provided at the top of the second cylinder and used for injecting oxidant;

[0030] and a second irradiation device arranged at the top of the second cylinder and used for irradiation.

[0031] Furthermore, the irradiation dose of the second irradiation device is 100 to 1000 kGy, preferably 200 to 500 kGy;

[0032] The radiation source of the second irradiation device includes a low- to medium-energy electron beam radiation source, a high-energy electron beam radiation source, or a gamma-ray radiation source.

[0033] Furthermore, the system also includes a circulation unit for circulating the secondary purified water flowing out of the oxidation irradiation unit to the reduction irradiation unit, and the circulation unit includes a circulation pipeline with one end connected between the oxidation irradiation unit and the purified water collection unit and the other end connected to the reduction irradiation unit.

[0034] Furthermore, the circulation unit further includes:

[0035] a three-way valve connecting the oxidation irradiation unit, the reduction irradiation unit and the circulation pipeline;

[0036] And a detection component connected between the oxidation irradiation unit and the three-way valve and used to detect the concentrations of perfluorinated pollutants, microplastics and COD in the secondary purified water flowing out of the oxidation irradiation unit.

[0037] Furthermore, the detection components are high performance liquid chromatography mass spectrometry, pyrolysis gas chromatography quadrupole-time of flight mass spectrometry and COD online analyzer.

[0038] Furthermore, a second flow controller is provided between the oxidation irradiation unit and the three-way valve for controlling the circulation flow rate or outflow flow rate of the second purified water.

[0039] Furthermore, the three-way valve is connected to a controller, and the controller is controlled by PLC.

[0040] Furthermore, the purified water collection unit includes:

[0041] The third cylinder;

[0042] a third liquid inlet provided on the third cylinder and used for the inflow of secondary purified water;

[0043] And a third liquid outlet is provided on the third cylinder and is used for the secondary purified water to flow out.

[0044] On the other hand, the present invention also provides a process for removing microplastics and perfluorinated pollutants in wastewater, which is implemented using the system and includes the following steps:

[0045] S1. Passing the wastewater containing microplastics and perfluorinated pollutants into the reduction and irradiation unit for reduction and irradiation treatment, wherein the perfluorinated pollutants in the wastewater containing microplastics and perfluorinated pollutants are decomposed and removed by reducing free radicals through a defluorination process to obtain primary purified water;

[0046] S2. Passing the primary purified water into the oxidative irradiation unit to perform oxidation and secondary irradiation treatment on the primary purified water. Under the action of the strong oxidative irradiation unit, the degradation intermediates of perfluorinated pollutants and microplastics and organic pollutants in the wastewater in the primary purified water can be further oxidized and decomposed by oxidative free radicals to obtain secondary purified water;

[0047] S3. Collect the secondary purified water through the purified water collection unit, and complete.

[0048] Furthermore, the reducing agent added to the reduction irradiation unit includes hydrogen sulfide, sodium dithionite, sodium bisulfite, ferrous sulfate, calcium polysulfide, divalent iron, zero-valent iron, sulfite, and sodium formate;

[0049] The concentration of the reducing agent added to the reduction irradiation unit in the wastewater containing microplastics and perfluorinated pollutants is 0.01 to 1 mol / L, preferably 0.01 to 0.5 mol / L;

[0050] The oxidant added to the oxidation irradiation unit includes persulfate, hydrogen peroxide, peracetic acid, peroxymonosulfate, percarbonate, permanganate and ozone;

[0051] The concentration of the oxidant added to the oxidation irradiation unit in the primary purified water is 0.01 to 1 mol / L, preferably 0.01 to 0.5 mol / L.

[0052] Furthermore, the inlet flow rate of the wastewater containing microplastics and perfluorinated pollutants is 1 to 20 m 3 / h, preferably 1 to 15m 3 / h.

[0053] Furthermore, the outflow speed of the secondary purified water is 1 to 20 m 3 / h, preferably 1 to 10 m 3 / h.

[0054] Furthermore, when the system includes a circulation unit, the secondary purified water flowing out of the oxidation irradiation unit is returned to the reduction irradiation unit through the circulation unit, and steps S1 and S2 are repeated, and the secondary purified water flowing out last is collected in the purified water collection unit.

[0055] Furthermore, the number of cycles is 1 to 30 times.

[0056] Furthermore, when the circulation unit includes a three-way valve and a detection component, when the detection component detects that the concentration of perfluorinated pollutants in the secondary purified water is lower than 0.04ug / L, the COD concentration is lower than 40mg / L, and the microplastic concentration is lower than 0.5g / L, the three-way valve is controlled to allow the secondary purified water to flow into the purified water collection unit; otherwise, the three-way valve is controlled to allow the secondary purified water to flow into the reduction irradiation unit through the circulation pipeline, and steps S1 and S2 are repeated until the concentration of perfluorinated pollutants is lower than 0.04ug / L, the COD concentration is lower than 40mg / L, and the microplastic concentration is lower than 0.5g / L.

[0057] Compared with the prior art, the present invention has the following advantages:

[0058] (1) The present invention provides a system and process for removing microplastics and perfluorinated pollutants from wastewater. The innovative design of a reduction irradiation unit and an oxidation irradiation unit allows for the simultaneous removal of perfluorinated pollutants and organic, refractory pollutants from wastewater. This invention pioneers the use of two degradation units, leveraging the combined effects of active free radicals generated by irradiation and those generated by reducing agents / oxidants to enhance the treatment performance of wastewater containing microplastics and perfluorinated pollutants.

[0059] (2) The secondary purified water after oxidative irradiation of the present invention is further returned to the reduction irradiation unit and irradiated again until the concentrations of perfluorinated pollutants and COD in the wastewater to be treated are lower than the national standards. The entire process has many advantages such as fast treatment rate, clean and environmental protection, low treatment cost and simple operation.

[0060] (3) The present invention provides a system and process for removing microplastics and perfluorinated pollutants from wastewater. The reduction irradiation unit and the oxidation irradiation unit are used to irradiate wastewater containing microplastics and perfluorinated pollutants; the circulation unit returns the treated wastewater to the irradiation treatment unit for irradiation again to ensure that the treated wastewater indicators meet the standards.

[0061] (4) The present invention is provided with a first flow controller and a second flow controller for regulating the water inlet flow and the wastewater flow returned to the reduction irradiation unit, ensuring that the entire process is automatically controlled without the need for manual intervention and control, thereby realizing the automated treatment of wastewater containing microplastics and perfluorinated pollutants.

[0062] (5) The present invention determines the concentration of the reducing agent added and the irradiation dose based on the concentration of perfluorinated pollutants in the wastewater, thereby achieving complete removal of perfluorinated pollutants within a wide range of concentrations. The concentration of the oxidant added and the irradiation dose are determined based on the COD concentration in the wastewater, thereby achieving effective degradation and removal of microplastics and difficult-to-degrade organic pollutants in the wastewater.

[0063] (6) The present invention provides a system and process for removing microplastic-containing perfluorinated pollutants from wastewater. The overall process operation is simple, and it can effectively remove wastewater containing microplastic-containing perfluorinated pollutants and effectively purify the wastewater. It has broad application prospects in the field of wastewater treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 Schematic diagram of the system for removing microplastics and perfluorinated pollutants from wastewater as shown in Example 1;

[0065] Figure 2 Figure 4 shows the changes in PFOS concentration in treated water (a) and mass loss of microplastics (b) at different irradiation doses.

[0066] Figure 3 Schematic diagram of the system for removing microplastics and perfluorinated pollutants from wastewater as shown in Example 5;

[0067] Figure 4 The concentration changes of PFOA, COD (a) and microplastics (b) in wastewater at different cycle times shown in Example 5;

[0068] Figure 5 The concentration changes of PFOA, COD (a) and microplastics (b) in wastewater at different cycle times shown in Example 6;

[0069] Figure 6 Schematic diagram of the system for removing microplastic and perfluorinated pollutants from wastewater as shown in Example 7.

[0070] Description of the marks in the figure:

[0071] 1-reduction irradiation unit, 11-first cylinder, 12-first liquid inlet, 13-first liquid outlet, 14-reducing agent input port, 15-first irradiation device, 16-first flow controller;

[0072] 2-oxidation irradiation unit, 21-second cylinder, 22-second liquid inlet, 23-second liquid outlet, 24-oxidant input port, 25-second irradiation device, 26-second flow controller;

[0073] 3-purified water collecting unit, 31-third cylinder, 32-third liquid inlet, 33-third liquid outlet;

[0074] 4-circulation unit, 41-circulation pipeline, 42-three-way valve, 43-detection component. DETAILED DESCRIPTION

[0075] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. The embodiments are based on the technical solutions of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments. In the following embodiments or examples, unless otherwise specified, functional components or structures are conventional components or conventional structures used in the art to achieve the corresponding functions.

[0076] It should be noted that in the description of the present invention, the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," "the other end," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0077] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "provided with," "connected," etc., should be understood in a broad sense. For example, "connected" may refer to a fixed connection, a detachable connection, or an integral connection; it may refer to a mechanical connection or an electrical connection; it may refer to a direct connection or an indirect connection through an intermediate medium; it may refer to internal communication between two components. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0078] Unless otherwise specified, the reagents, methods, instruments and equipment used in the present invention are conventional reagents, methods, instruments and equipment in the art.

[0079] In the following examples, wastewater was prepared in the laboratory. River water was collected as the bottom substrate, and high concentrations of perfluorinated pollutants and microplastics were subsequently added to the water to prepare the experimental wastewater. The perfluorinated pollutants were perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), both purchased from China National Pharmaceutical Group Co., Ltd. The microplastics were polypropylene, polyvinyl chloride, and polylactic acid microplastic particles, all purchased from Guangzhou Hengfa Plastics Co., Ltd., China.

[0080] In the following embodiments, the first irradiation device and the second irradiation device were both purchased from the medium and low energy electron accelerator of Shanghai Pioneer Electric Factory, model GJ-Ⅱ. The concentration of perfluorinated pollutants was detected by quadrupole time-of-flight liquid chromatography mass spectrometry, and the mass spectrometer was purchased from Abbott, USA, model X500R QTOF. COD was detected by a COD online analyzer, purchased from Hach Company, USA, model CODmax III. The concentration of microplastics was detected by pyrolysis gas chromatography quadrupole-time-of-flight mass spectrometry, and the mass spectrometer was purchased from Agilent, USA, model 7890A-7200 (Q-TOF) GC / MS. The flow controllers were all purchased from SMC Corporation of Japan, model FC2W-X110 water flow controller.

[0081] Irradiation technology uses high-energy rays (such as gamma rays or electron beams) to act directly on pollutant molecules. Through ionization and excitation, the pollutant molecules undergo a series of physical, chemical, and biochemical changes, thereby achieving rapid degradation or harmless treatment of the pollutants. Irradiation is an efficient and environmentally friendly method that is often used to treat wastewater, dyes, antibiotics, or other difficult-to-degrade organic pollutants. Compared with other wastewater treatment technologies, irradiation technology has many advantages, including: the use of irradiation technology does not produce additional pollutants, it has strong penetrating power in water, and the irradiation process can disinfect the wastewater while degrading pollutants.

[0082] Based on this, the present invention aims to provide a system and process for the efficient, simple, and harmless removal of microplastics and perfluorinated pollutants from wastewater using irradiation technology. The free radicals generated during the irradiation process and the active particles produced by the reducing / oxidizing agents interact with the wastewater containing microplastics and perfluorinated pollutants, achieving harmless degradation and treatment of the wastewater containing microplastics and perfluorinated pollutants. This addresses the difficulties and obstacles in treating microplastics and perfluorinated pollutants. Through multiple cycles of irradiation treatment, the wastewater containing microplastics and perfluorinated pollutants can ultimately be completely purified.

[0083] A system for removing microplastics and perfluorinated pollutants in wastewater, which is used for removing microplastics and perfluorinated pollutants in wastewater, and the system comprises:

[0084] Reduction and irradiation unit 1, which performs reduction and irradiation treatment on wastewater containing microplastics and perfluorinated pollutants to obtain primary purified water;

[0085] The oxidation irradiation unit 2 connected to the reduction irradiation unit 1 performs oxidation and secondary irradiation treatment on the primary purified water to obtain secondary purified water;

[0086] and a purified water collecting unit 3 connected to the oxidation irradiation unit 2 and used for collecting secondary purified water.

[0087] In some specific embodiments, the system targets wastewater containing microplastics and perfluorinated pollutants, and through the construction of a reducing irradiation system and an oxidizing irradiation system, it achieves both the reduction removal of perfluorinated pollutants and the oxidation purification of the wastewater.

[0088] In some specific embodiments, the microplastics and perfluorinated pollutants include perfluorinated pollutants and microplastics;

[0089] The perfluorinated pollutants include PFCAs, PFSAs, PFASs or perfluorinated telomers;

[0090] The microplastics include PP, PE, PVC, PS, PU, ​​PET or PLA;

[0091] The perfluorinated pollutant concentration is 4×10 -5 ~200mg / L, preferably 0.0001~150mg / L;

[0092] The concentration of the microplastics is 0.00001 to 5 g / L, preferably 0.001 to 2 g / L.

[0093] In some specific embodiments, the reducing irradiation unit 1 includes:

[0094] First cylinder 11;

[0095] A first liquid inlet 12 provided on the first cylinder 11 and used for the inflow of wastewater containing microplastics and perfluorinated pollutants;

[0096] a first liquid outlet 13 provided on the first cylinder 11 and used for the primary purified water to flow out;

[0097] a reducing agent inlet 14 provided on the top of the first cylinder 11 and used for injecting reducing agent;

[0098] And a first irradiation device 15 is provided at the top of the first cylinder 11 and is used for irradiation.

[0099] In some specific embodiments, the irradiation dose of the first irradiation device is 100 to 1000 kGy, preferably 200 to 500 kGy;

[0100] The radiation source of the first irradiation device 15 includes a low- to medium-energy electron beam radiation source, a high-energy electron beam radiation source, or a gamma-ray radiation source.

[0101] In some specific embodiments, a first flow controller 16 is provided on the pipeline connected to the first liquid inlet 12 for controlling the inlet flow rate of the wastewater containing microplastics and perfluorinated pollutants.

[0102] In some specific embodiments, the oxidative irradiation unit 2 includes:

[0103] Second cylinder 21;

[0104] a second liquid inlet 22 provided on the second cylinder 21 and used for primary purified water to flow in;

[0105] a second liquid outlet 23 provided on the second cylinder 21 and used for the secondary purified water to flow out;

[0106] an oxidant inlet 24 provided at the top of the second cylinder 21 and used for injecting oxidant;

[0107] and a second irradiation device 25 disposed at the top of the second cylinder 21 and used for irradiation.

[0108] In some specific embodiments, the irradiation dose of the second irradiation device is 100 to 1000 kGy, preferably 200 to 500 kGy;

[0109] The radiation source of the second irradiation device 25 includes a low- to medium-energy electron beam radiation source, a high-energy electron beam radiation source, or a gamma ray radiation source.

[0110] In some specific embodiments, in order to ensure that wastewater treatment meets national emission standards, the system also includes a circulation unit 4 for circulating the secondary purified water flowing out of the oxidation irradiation unit 2 to the reduction irradiation unit 1, and the circulation unit 4 includes a circulation pipeline 41 connected between the oxidation irradiation unit 2 and the purified water collection unit 3 at one end and connected to the reduction irradiation unit 1 at the other end.

[0111] In some specific embodiments, the circulation unit 4 further includes:

[0112] a three-way valve 42 connecting the oxidation irradiation unit 2, the reduction irradiation unit 1 and the circulation pipeline 41;

[0113] And a detection component 43 connected between the oxidation irradiation unit 2 and the three-way valve 42 and used to detect the concentrations of perfluorinated pollutants, microplastics and COD in the secondary purified water flowing out of the oxidation irradiation unit 2.

[0114] In some specific embodiments, the three-way valve 42 is connected to a controller, and the controller is controlled by PLC.

[0115] In some specific embodiments, the detection component 43 is a high performance liquid chromatography mass spectrometer, a pyrolysis gas chromatography quadrupole-time of flight mass spectrometer, and a COD online analyzer.

[0116] In some specific embodiments, a second flow controller 26 is provided between the oxidation irradiation unit 2 and the three-way valve 42 for controlling the circulation flow rate or outflow flow rate of the second purified water.

[0117] In some specific embodiments, the purified water collecting unit 3 includes:

[0118] The third cylinder 41;

[0119] A third liquid inlet 32 ​​provided on the third cylinder 41 and used for the inflow of secondary purified water;

[0120] And a third liquid outlet 33 is provided on the third cylinder 41 and is used for the secondary purified water to flow out.

[0121] A process for removing microplastics and perfluorinated pollutants from wastewater, which is implemented using the system, comprises the following steps:

[0122] S1. Passing the wastewater containing microplastics and perfluorinated pollutants into the reduction and irradiation unit 1 for reduction and irradiation treatment, wherein the perfluorinated pollutants in the wastewater containing microplastics and perfluorinated pollutants are decomposed and removed by reducing free radicals through a defluorination process to obtain primary purified water;

[0123] S2, passing the primary purified water into the oxidative irradiation unit 2, oxidizing and secondary irradiating the primary purified water. Under the action of the strong oxidative irradiation unit, the degradation intermediates of perfluorinated pollutants and the microplastics and organic pollutants in the wastewater in the primary purified water can be further oxidized and decomposed by oxidative free radicals to obtain secondary purified water;

[0124] S3. Collect the secondary purified water through the purified water collecting unit 3. Complete.

[0125] In some specific embodiments, the reducing agent added to the reducing irradiation unit 1 includes hydrogen sulfide, sodium dithionite, sodium bisulfite, ferrous sulfate, calcium polysulfide, divalent iron, zero-valent iron, sulfite, and sodium formate;

[0126] The concentration of the reducing agent added to the reduction irradiation unit 1 in the wastewater containing microplastics and perfluorinated pollutants is 0.01 to 1 mol / L, preferably 0.01 to 0.5 mol / L;

[0127] The oxidizing agent introduced into the oxidizing irradiation unit 2 includes persulfate, hydrogen peroxide, peracetic acid, peroxymonosulfate, percarbonate, permanganate and ozone;

[0128] The concentration of the oxidant added to the oxidation irradiation unit 2 in the primary purified water is 0.001 to 1 mol / L, preferably 0.01 to 0.5 mol / L.

[0129] In some specific embodiments, in step S1, a reducing agent is first added to the reduction irradiation unit 1, and then irradiation treatment is performed. During the irradiation process, on the one hand, the water molecules are activated by the indirect effect of irradiation, generating active species such as hydrated electrons and hydrogen free radicals. These active species can directly react with perfluorinated pollutants to remove them; on the other hand, irradiation acts on the strong reducing agent, causing it to produce a variety of reducing active ions. The reducing active particles react with perfluorinated pollutants and microplastics, promoting the defluorination degradation of perfluorinated pollutants and the aging removal of microplastics.

[0130] In some specific embodiments, in step S2, an oxidant is first added to the oxidation irradiation unit 2, and then a secondary irradiation treatment is performed. During the irradiation treatment, on the one hand, the water molecules are activated by the indirect effect of irradiation, generating active species such as hydroxyl radicals. These active species can directly react with the degradation intermediates of perfluorinated pollutants and microplastics in the wastewater to remove them; on the other hand, the irradiation acts on the strong oxidant, causing the strong oxidant to produce a variety of oxidative active ions. The oxidative active particles react with the degradation intermediates of perfluorinated pollutants and the refractory organic pollutants in the wastewater, promoting the degradation and removal of the degradation intermediates of perfluorinated pollutants and the refractory organic pollutants in the wastewater.

[0131] In some specific embodiments, the inlet flow rate of the wastewater containing microplastics and perfluorinated pollutants is 1 to 20 m 3 / h, preferably 1 to 15m 3 / h.

[0132] In some specific embodiments, the outflow velocity of the secondary purified water is 0.3-1.5 m / s, preferably 0.5-1.0 m / s.

[0133] In some specific embodiments, when the system includes a circulation unit 4, in order to ensure that the wastewater treatment meets the national emission standards, the secondary purified water flowing out of the oxidation irradiation unit 2 is returned to the reduction irradiation unit 1 through the circulation unit 4, and steps S1 and S2 are repeated, and the secondary purified water flowing out last is collected in the purified water collection unit 3.

[0134] In some specific embodiments, the number of cycles is 1 to 30 times.

[0135] In some specific embodiments, when the circulation unit 4 includes a three-way valve 42 and a detection component 43, when the detection component 43 detects that the concentration of perfluorinated pollutants in the secondary purified water is lower than 0.04ug / L, the COD concentration is lower than 40mg / L, and the microplastic concentration is lower than 0.5g / L, the three-way valve 42 is controlled to allow the secondary purified water to flow into the purified water collection unit 3; otherwise, the three-way valve 42 is controlled to allow the secondary purified water to flow into the reduction irradiation unit 1 through the circulation pipeline 41, and steps S1 and S2 are repeated until the concentration of perfluorinated pollutants is lower than 0.04ug / L, the COD concentration is lower than 40mg / L, and the microplastic concentration is lower than 0.5g / L.

[0136] The above embodiments may be implemented individually or in any combination of two or more.

[0137] The following describes the details with reference to specific embodiments.

[0138] Example 1

[0139] A system for removing microplastics and perfluorinated pollutants in wastewater, which is used to remove microplastics and perfluorinated pollutants in wastewater, such as Figure 1 As shown, the system includes:

[0140] Reduction and irradiation unit 1, which performs reduction and irradiation treatment on wastewater containing microplastics and perfluorinated pollutants to obtain primary purified water;

[0141] The oxidation irradiation unit 2 connected to the reduction irradiation unit 1 performs oxidation and secondary irradiation treatment on the primary purified water to obtain secondary purified water;

[0142] and a purified water collecting unit 3 connected to the oxidation irradiation unit 2 and used for collecting secondary purified water.

[0143] In this embodiment, the microplastic composite perfluorinated pollutants include perfluorinated pollutants and microplastics; the perfluorinated pollutants are perfluorooctane sulfonic acid, with a concentration of 10 mg / L; and the microplastics are polypropylene, with a concentration of 1 g / L.

[0144] In this embodiment, the reducing irradiation unit 1 includes:

[0145] First cylinder 11;

[0146] A first liquid inlet 12 provided on the first cylinder 11 and used for the inflow of wastewater containing microplastics and perfluorinated pollutants;

[0147] a first liquid outlet 13 provided on the first cylinder 11 and used for the primary purified water to flow out;

[0148] a reducing agent inlet 14 provided on the top of the first cylinder 11 and used for injecting reducing agent;

[0149] And a first irradiation device 15 is provided at the top of the first cylinder 11 and is used for irradiation.

[0150] In this embodiment, the irradiation dose of the first irradiation device 15 is 200 kGy, and the radiation source of the first irradiation device 15 is a low-medium energy electron beam radiation source.

[0151] In this embodiment, a first flow controller 16 is provided on the pipeline connected to the first liquid inlet 12 for controlling the inlet flow rate of the wastewater containing microplastics and perfluorinated pollutants.

[0152] In this embodiment, the oxidation irradiation unit 2 includes:

[0153] Second cylinder 21;

[0154] a second liquid inlet 22 provided on the second cylinder 21 and used for primary purified water to flow in;

[0155] a second liquid outlet 23 provided on the second cylinder 21 and used for the secondary purified water to flow out;

[0156] an oxidant inlet 24 provided at the top of the second cylinder 21 and used for injecting oxidant;

[0157] and a second irradiation device 25 disposed at the top of the second cylinder 21 and used for irradiation.

[0158] In this embodiment, the irradiation dose of the second irradiation device 25 is 200 kGy. The radiation source of the second irradiation device 25 is a low-medium energy electron beam radiation source.

[0159] The radiation source of the second irradiation device 25 includes a low- to medium-energy electron beam radiation source, a high-energy electron beam radiation source, or a gamma ray radiation source.

[0160] In this embodiment, the purified water collecting unit 3 includes:

[0161] The third cylinder 41;

[0162] A third liquid inlet 32 ​​provided on the third cylinder 41 and used for the inflow of secondary purified water;

[0163] And a third liquid outlet 33 is provided on the third cylinder 41 and is used for the secondary purified water to flow out.

[0164] A process for removing microplastics and perfluorinated pollutants from wastewater, which is implemented using the system, comprises the following steps:

[0165] S1. Passing the wastewater containing microplastics and perfluorinated pollutants into the reduction and irradiation unit 1 for reduction and irradiation treatment, wherein the perfluorinated pollutants in the wastewater containing microplastics and perfluorinated pollutants are decomposed and removed by reducing free radicals through a defluorination process to obtain primary purified water;

[0166] S2, passing the primary purified water into the oxidative irradiation unit 2, oxidizing and secondary irradiating the primary purified water. Under the action of the strong oxidative irradiation unit, the degradation intermediates of perfluorinated pollutants and the microplastics and organic pollutants in the wastewater in the primary purified water can be further oxidized and decomposed by oxidative free radicals to obtain secondary purified water;

[0167] S3. Collect the secondary purified water through the purified water collecting unit 3. Complete.

[0168] In this embodiment, the reducing agent added to the reduction irradiation unit 1 is sodium formate, and its concentration in the wastewater containing microplastics and perfluorinated pollutants is 0.02 mol / L. The oxidizing agent added to the oxidation irradiation unit 2 is hydrogen peroxide, and its concentration is 0.01 mol / L.

[0169] In this embodiment, in step S1, a reducing agent is first introduced into the reduction irradiation unit 1, and irradiation treatment is performed five minutes after the introduction. During the irradiation process, on the one hand, the water molecules are activated by the indirect effect of irradiation, generating active species such as hydrated electrons and hydrogen radicals. These active species can directly react with perfluorinated pollutants and remove them. On the other hand, irradiation acts on the strong reducing agent, causing it to produce a variety of reducing active ions. These reducing active particles react with perfluorinated pollutants and microplastics, promoting the defluorination and degradation of perfluorinated pollutants and the aging and removal of microplastics.

[0170] In this embodiment, in step S2, an oxidant is first added to the oxidation irradiation unit 2, and a secondary irradiation treatment is performed five minutes after the addition. During the irradiation treatment, on the one hand, the water molecules are activated by the indirect effect of irradiation, generating active species such as hydroxyl radicals. These active species can directly react with the degradation intermediates of perfluorinated pollutants and microplastics in the wastewater to remove them; on the other hand, the irradiation acts on the strong oxidant, causing the strong oxidant to produce a variety of oxidative active ions. The oxidative active particles react with the degradation intermediates of perfluorinated pollutants and the refractory organic pollutants in the wastewater, promoting the degradation and removal of the degradation intermediates of perfluorinated pollutants and the refractory organic pollutants in the wastewater.

[0171] In this embodiment, the inlet flow rate of the wastewater containing microplastics and perfluorinated pollutants is 10m 3 / h.

[0172] In this embodiment, the outflow velocity of the secondary purified water is 0.8 m / s.

[0173] Example 2

[0174] A system for removing microplastic-complex perfluorinated pollutants from wastewater, the same as that in Example 1.

[0175] A process for removing microplastic-composite perfluorinated pollutants in wastewater. Compared with Example 1, the irradiation dose of the first irradiation device 15 is adjusted to 300 kGy, and the irradiation dose of the second irradiation device 25 is adjusted to 300 kGy.

[0176] Example 3

[0177] A system for removing microplastic-complex perfluorinated pollutants from wastewater, the same as that in Example 1.

[0178] A process for removing microplastic-composite perfluorinated pollutants in wastewater. Compared with Example 1, the irradiation dose of the first irradiation device 15 is adjusted to 400 kGy, and the irradiation dose of the second irradiation device 25 is adjusted to 400 kGy.

[0179] Example 4

[0180] A system for removing microplastic-complex perfluorinated pollutants from wastewater, the same as that in Example 1.

[0181] A process for removing microplastic-composite perfluorinated pollutants in wastewater. Compared with Example 1, the irradiation dose of the first irradiation device 15 is adjusted to 500 kGy, and the irradiation dose of the second irradiation device 25 is adjusted to 500 kGy.

[0182] from Figure 2 It can be seen that with the continuous increase of irradiation dose, the concentration of perfluorooctane sulfonic acid shows a significant downward trend, significantly decreasing from 1.25ug / L to 0.028ug / L, and falling below the national standard limit level. With the continuous increase of irradiation dose, it can also be observed that the mass loss of microplastics increases significantly. When the irradiation dose increases to 500kGy, the mass loss of microplastics reaches 73%, achieving effective removal of microplastics in water bodies. Through research, it can be proved that the system of the present invention can effectively achieve the effective removal of microplastics and perfluorinated pollutants, and can achieve effective removal of pollutants when the electron beam irradiation dose reaches 200-500kGy. Further increase in irradiation dose will greatly increase the system operating cost and irradiation treatment time, which is not conducive to large-scale treatment of microplastics and perfluorinated pollutants. Therefore, when operating the system, the irradiation dose should be set to 200-500kGy.

[0183] Example 5

[0184] A system for removing microplastics and perfluorinated pollutants in wastewater, which is used to remove microplastics and perfluorinated pollutants in wastewater, such as Figure 3 As shown, the system includes:

[0185] Reduction and irradiation unit 1, which performs reduction and irradiation treatment on wastewater containing microplastics and perfluorinated pollutants to obtain primary purified water;

[0186] The oxidation irradiation unit 2 connected to the reduction irradiation unit 1 performs oxidation and secondary irradiation treatment on the primary purified water to obtain secondary purified water;

[0187] and a purified water collecting unit 3 connected to the oxidation irradiation unit 2 and used for collecting secondary purified water.

[0188] In this embodiment, the microplastic composite perfluorinated pollutants include perfluorinated pollutants and microplastics; the perfluorinated pollutants are perfluorooctanoic acid with a concentration of 1 mg / L; the microplastics are PVC with a concentration of 2 g / L, and the COD concentration is 900 mg / L.

[0189] In this embodiment, the reducing irradiation unit 1 includes:

[0190] First cylinder 11;

[0191] A first liquid inlet 12 provided on the first cylinder 11 and used for the inflow of wastewater containing microplastics and perfluorinated pollutants;

[0192] a first liquid outlet 13 provided on the first cylinder 11 and used for the primary purified water to flow out;

[0193] a reducing agent inlet 14 provided on the top of the first cylinder 11 and used for injecting reducing agent;

[0194] And a first irradiation device 15 is provided at the top of the first cylinder 11 and is used for irradiation.

[0195] In this embodiment, the irradiation dose of the first irradiation device 15 is 400 kGy, and the radiation source of the first irradiation device 15 is a low-medium energy electron beam radiation source.

[0196] In this embodiment, a first flow controller 16 is provided on the pipeline connected to the first liquid inlet 12 for controlling the inlet flow rate of the wastewater containing microplastics and perfluorinated pollutants.

[0197] In this embodiment, the oxidation irradiation unit 2 includes:

[0198] Second cylinder 21;

[0199] a second liquid inlet 22 provided on the second cylinder 21 and used for primary purified water to flow in;

[0200] a second liquid outlet 23 provided on the second cylinder 21 and used for the secondary purified water to flow out;

[0201] an oxidant inlet 24 provided at the top of the second cylinder 21 and used for injecting oxidant;

[0202] and a second irradiation device 25 disposed at the top of the second cylinder 21 and used for irradiation.

[0203] In this embodiment, the irradiation dose of the second irradiation device 25 is 300 kGy, and the radiation source of the second irradiation device 25 is a low-medium energy electron beam radiation source.

[0204] The radiation source of the second irradiation device 25 includes a low- to medium-energy electron beam radiation source, a high-energy electron beam radiation source, or a gamma ray radiation source.

[0205] In this embodiment, the purified water collecting unit 3 includes:

[0206] The third cylinder 41;

[0207] A third liquid inlet 32 ​​provided on the third cylinder 41 and used for the inflow of secondary purified water;

[0208] And a third liquid outlet 33 is provided on the third cylinder 41 and is used for the secondary purified water to flow out.

[0209] In this embodiment, in order to ensure that the wastewater treatment meets the national emission standards, the system also includes a circulation unit 4 for circulating the secondary purified water flowing out of the oxidation irradiation unit 2 to the reduction irradiation unit 1, and the circulation unit 4 includes a circulation pipeline 41 connected between the oxidation irradiation unit 2 and the purified water collection unit 3 at one end and connected to the reduction irradiation unit 1 at the other end.

[0210] In this embodiment, a second flow controller 26 is provided between the oxidation irradiation unit 2 and the circulation pipeline 41 for controlling the circulation flow rate or outflow flow rate of the second purified water.

[0211] A process for removing microplastics and perfluorinated pollutants from wastewater, which is implemented using the system, comprises the following steps:

[0212] S1. Passing the wastewater containing microplastics and perfluorinated pollutants into the reduction and irradiation unit 1 for reduction and irradiation treatment, wherein the perfluorinated pollutants in the wastewater containing microplastics and perfluorinated pollutants are decomposed and removed by reducing free radicals through a defluorination process to obtain primary purified water;

[0213] S2, passing the primary purified water into the oxidative irradiation unit 2, oxidizing and secondary irradiating the primary purified water. Under the action of the strong oxidative irradiation unit, the degradation intermediates of perfluorinated pollutants and the microplastics and organic pollutants in the wastewater in the primary purified water can be further oxidized and decomposed by oxidative free radicals to obtain secondary purified water;

[0214] S3. In order to ensure that the wastewater treatment meets the national emission standards, the secondary purified water flowing out of the oxidation irradiation unit 2 is returned to the reduction irradiation unit 1 through the circulation unit 4, and steps S1 and S2 are repeated. The secondary purified water flowing out last is collected in the purified water collection unit 3 to complete.

[0215] In this embodiment, the reducing agent added to the reduction irradiation unit 1 is sodium sulfite, and its concentration in the wastewater containing microplastics and perfluorinated pollutants is 0.02 mol / L. The oxidizing agent added to the oxidation irradiation unit 2 is hydrogen peroxide, and its concentration is 0.01 mol / L.

[0216] In this embodiment, in step S1, a reducing agent is first introduced into the reduction irradiation unit 1, and irradiation treatment is performed five minutes after the introduction. During the irradiation process, on the one hand, the water molecules are activated by the indirect effect of irradiation, generating active species such as hydrated electrons and hydrogen radicals. These active species can directly react with perfluorinated pollutants and remove them. On the other hand, irradiation acts on the strong reducing agent, causing it to produce a variety of reducing active ions. These reducing active particles react with perfluorinated pollutants and microplastics, promoting the defluorination and degradation of perfluorinated pollutants and the aging and removal of microplastics.

[0217] In this embodiment, in step S2, an oxidant is first added to the oxidation irradiation unit 2, and a secondary irradiation treatment is performed five minutes after the addition. During the irradiation treatment, on the one hand, the water molecules are activated by the indirect effect of irradiation, generating active species such as hydroxyl radicals. These active species can directly react with the degradation intermediates of perfluorinated pollutants and microplastics in the wastewater to remove them; on the other hand, the irradiation acts on the strong oxidant, causing the strong oxidant to produce a variety of oxidative active ions. The oxidative active particles react with the degradation intermediates of perfluorinated pollutants and the refractory organic pollutants in the wastewater, promoting the degradation and removal of the degradation intermediates of perfluorinated pollutants and the refractory organic pollutants in the wastewater.

[0218] In this embodiment, the inlet flow rate of the wastewater containing microplastics and perfluorinated pollutants is 12m 3 / h.

[0219] In this embodiment, the number of cycles is 3, and the concentration of the secondary purified water in each cycle is as follows: Figure 4 As shown, the concentration of perfluorooctanoic acid that finally flows into the purified water collection unit 3 and is put into the secondary purified water is lower than 0.04ug / L, the COD concentration is lower than 40mg / L, and the microplastic concentration is lower than 0.5g / L. Figure 4 It can be seen that with the continuous increase in the number of cycle treatments, the concentration of microplastics and perfluorinated pollutants in the water body is also significantly reduced. In the first cycle, the concentration of perfluorooctanoic acid has been significantly reduced to 0.09 mg / L. When it reaches the third cycle, it can be detected that the concentration of perfluorooctanoic acid is lower than the national detection standard. In the first cycle, the COD concentration was 362 mg / L. As the number of cycles increased to 3 times, the COD concentration dropped rapidly to 38 mg / L. As the number of cycles increased, it can also be noticed that the concentration of microplastics showed a significant downward trend. As the number of cycles increased, it can be observed that the concentration of microplastics decreased from 2 g / L to 0.27 g / L. The above examples show that with the increase in the number of cycles, the concentration of microplastics and perfluorinated pollutants in water bodies will show a significant downward trend, proving that the present invention has excellent treatment efficiency for microplastics and perfluorinated pollutants in water bodies.

[0220] Example 6

[0221] In this embodiment, the wastewater containing microplastics and perfluorinated pollutants includes perfluorinated pollutants and microplastics; the perfluorinated pollutants are perfluorooctane sulfonic acid with a concentration of 5 mg / L; the microplastics are PLA with a concentration of 2 g / L, and the COD concentration is 500 mg / L.

[0222] A system for removing microplastic-complex perfluorinated pollutants from wastewater, the same as that in Example 2.

[0223] A process for removing microplastics and perfluorinated pollutants from wastewater is similar to that of Example 2, except that in this embodiment, the reducing agent added to the reduction irradiation unit 1 is sodium bisulfite, and the concentration in the wastewater containing microplastics and perfluorinated pollutants is 0.02 mol / L. The oxidizing agent added to the oxidation irradiation unit 2 is potassium persulfate, and the concentration is 0.05 mol / L. The number of cycles is 4, and the concentration of the secondary purified water in each cycle is as follows: Figure 4 As shown, the concentration of PFOS that finally flows into the purified water collection unit 3 and is put into the secondary purified water is lower than 0.04ug / L, the COD concentration is lower than 40mg / L, and the microplastic concentration is lower than 0.5g / L. Figure 5 It can be seen that with the continuous increase in the number of cycle treatments, the concentrations of microplastics, perfluorinated pollutants and COD in the water body are also significantly reduced. In the first cycle, the concentration of perfluorooctanoic acid has been significantly reduced from 5mg / L to 0.78mg / L. When the fourth cycle is reached, it can be detected that the concentration of perfluorooctanoic acid is lower than the national detection standard. In the first cycle, the COD concentration is 128mg / L. As the number of cycles increases to 4 times, the COD concentration drops rapidly to 12.8mg / L, which is far below the national effluent detection standard. As the number of cycles increases, it can also be noticed that the concentration of microplastics shows a significant downward trend. As the number of cycles increases, it can be observed that the concentration of microplastics decreases from 2g / L to 0.026g / L. The above examples show that with the increase in the number of cycles, the concentration of microplastics and perfluorinated pollutants in water bodies will show a significant downward trend, proving that the present invention has excellent treatment efficiency for microplastics and perfluorinated pollutants in water bodies.

[0224] Example 7

[0225] A system for removing microplastics and perfluorinated pollutants from wastewater is provided based on Example 2, wherein the circulation unit 4 further comprises:

[0226] a three-way valve 42 connecting the oxidation irradiation unit 2, the reduction irradiation unit 1 and the circulation pipeline 41;

[0227] and a detection component 43 disposed between the oxidation irradiation unit 2 and the three-way valve 42 and used for detecting the concentrations of perfluorinated pollutants and COD in the secondary purified water flowing out of the oxidation irradiation unit 2 .

[0228] In this embodiment, the three-way valve 42 is connected to a controller, and the controller is controlled by a PLC.

[0229] In this embodiment, the detection component 43 is a high performance liquid chromatography mass spectrometer, a pyrolysis gas chromatography quadrupole-time of flight mass spectrometer and a COD online analyzer.

[0230] A process for removing microplastics and perfluorinated pollutants from wastewater is provided on the basis of Example 2. In step S3, when the detection component 43 detects that the concentration of perfluorinated pollutants in the secondary purified water is lower than 0.04ug / L, the COD concentration is lower than 40mg / L, and the microplastic concentration is lower than 0.5g / L, the three-way valve 42 is controlled to allow the secondary purified water to flow into the purified water collection unit 3; otherwise, the three-way valve 42 is controlled to allow the secondary purified water to flow into the reduction irradiation unit 1 through the circulation line 41, and steps S1 and S2 are repeated until the concentration of perfluorinated pollutants is lower than 0.04ug / L and the COD concentration is lower than 40mg / L. In this embodiment, after S1 and S2 are cycled three times, the detection component 43 detects that the concentration of perfluorinated pollutants in the secondary purified water is lower than 0.04ug / L and the COD concentration is lower than 40mg / L, and the three-way valve 42 is controlled to allow the secondary purified water to flow into the purified water collection unit 3.

[0231] In summary, the system and process of the present invention are characterized by good treatment effects, low carbon emissions, and simple operation. The irradiation conditions and reagent dosage can be adjusted according to the occurrence and conditions of microplastic and perfluorinated contaminants in wastewater to achieve the purpose of removing microplastic and perfluorinated contaminants. This process can meet the requirements of removing microplastic and perfluorinated contaminants of different types and concentrations in a variety of different environmental matrices, and has a good removal effect on wastewater containing microplastic and perfluorinated contaminants.

[0232] Although the present invention has been described in detail above using general explanations, specific embodiments, and experiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A system for removing microplastics and perfluorinated pollutants from wastewater, characterized in that: Used to remove microplastics and perfluorinated pollutants in wastewater, the system includes: The reduction and irradiation unit (1) performs reduction and irradiation treatment on the wastewater containing microplastics and perfluorinated pollutants to obtain primary purified water; an oxidizing irradiation unit (2) connected to the reducing irradiation unit (1) for performing oxidation and secondary irradiation treatment on the primary purified water to obtain secondary purified water; and a purified water collecting unit (3) connected to the oxidative irradiation unit (2) and used for collecting secondary purified water.

2. A system for removing microplastics and perfluorinated pollutants from wastewater according to claim 1, characterized in that: The microplastic composite perfluorinated pollutants include perfluorinated pollutants and microplastics; The perfluorinated pollutants include perfluorinated carboxylic acids, perfluorinated sulfonic acids, perfluorinated sulfonates or perfluorinated telomers; The microplastics include polypropylene, polyethylene, polyvinyl chloride, polystyrene, polyurethane, polyethylene terephthalate or polylactic acid; The perfluorinated pollutant concentration is 4×10 -5 ~200mg / L; The concentration of the microplastics is 0.00001 to 5 g / L.

3. A system for removing microplastics and perfluorinated pollutants from wastewater according to claim 1, characterized in that: The reducing irradiation unit (1) comprises: a first cylinder (11); a first liquid inlet (12) provided on the first cylinder (11) and used for the inflow of wastewater containing microplastics and perfluorinated pollutants; a first liquid outlet (13) provided on the first cylinder (11) and used for primary purified water to flow out; a reducing agent input port (14) provided at the top of the first cylinder (11) and used for inputting the reducing agent; and a first irradiation device (15) arranged at the top of the first cylinder (11) and used for irradiation.

4. A system for removing microplastics and perfluorinated pollutants from wastewater according to claim 3, characterized in that: The irradiation dose of the first irradiation device (15) is 100 to 1000 kGy; The radiation source of the first irradiation device (15) includes a low- to medium-energy electron beam radiation source, a high-energy electron beam radiation source, or a gamma ray radiation source.

5. The system for removing microplastics and perfluorinated pollutants from wastewater according to claim 1, characterized in that: The oxidation irradiation unit (2) comprises: a second cylinder (21); a second liquid inlet (22) provided on the second cylinder (21) and used for primary purified water to flow in; a second liquid outlet (23) provided on the second cylinder (21) and used for the secondary purified water to flow out; an oxidant inlet (24) provided at the top of the second cylinder (21) and used for injecting oxidant; and a second irradiation device (25) arranged at the top of the second cylinder (21) and used for irradiation.

6. A system for removing microplastics and perfluorinated pollutants from wastewater according to claim 5, characterized in that: The irradiation dose of the second irradiation device (25) is 100 to 1000 kGy; The radiation source of the second irradiation device (25) includes a low- to medium-energy electron beam radiation source, a high-energy electron beam radiation source, or a gamma ray radiation source.

7. The system for removing microplastics and perfluorinated pollutants from wastewater according to claim 1, characterized in that: The system further comprises a circulation unit (4) for circulating the secondary purified water flowing out of the oxidation irradiation unit (2) to the reduction irradiation unit (1), wherein the circulation unit (4) comprises a circulation pipeline (41) having one end connected between the oxidation irradiation unit (2) and the purified water collecting unit (3) and the other end connected to the reduction irradiation unit (1).

8. A system for removing microplastics and perfluorinated pollutants from wastewater according to claim 7, characterized in that: The circulation unit (4) further comprises: a three-way valve (42) connecting the oxidation irradiation unit (2), the reduction irradiation unit (1) and the circulation pipeline (41); and a detection component (43) connected between the oxidation irradiation unit (2) and the three-way valve (42) and used to detect the concentrations of perfluorinated pollutants, microplastics and COD in the secondary purified water flowing out of the oxidation irradiation unit (2).

9. A process for removing microplastics and perfluorinated pollutants from wastewater, which is implemented using the system according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, passing the wastewater containing microplastics and perfluorinated pollutants into the reduction and irradiation unit (1), performing reduction and irradiation treatment to obtain primary purified water; S2, passing the primary purified water into the oxidation irradiation unit (2), performing oxidation and secondary irradiation treatment on the primary purified water to obtain secondary purified water; S3. Collect the secondary purified water through the purified water collecting unit (3). Complete.

10. A process for removing microplastics and perfluorinated pollutants from wastewater according to claim 9, characterized in that: The reducing agent added to the reducing irradiation unit (1) includes hydrogen sulfide, sodium dithionite, sodium bisulfite, ferrous sulfate, calcium polysulfide, divalent iron, zero-valent iron, sulfite, and sodium formate; The concentration of the reducing agent added to the reduction irradiation unit (1) in the wastewater containing microplastics and perfluorinated pollutants is 0.01 to 1 mol / L; The oxidant introduced into the oxidative irradiation unit (2) includes persulfate, hydrogen peroxide, peracetic acid, peroxymonosulfate, percarbonate, permanganate and ozone; The concentration of the oxidant added to the oxidation irradiation unit (2) in the primary purified water is 0.01-1 mol / L.

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