Method and system for removing organic pollutants from reverse osmosis concentrate of coking wastewater on basis of electron beam irradiation process

Abstract

Provided are a method and system for removing organic pollutants from a reverse osmosis concentrate of coking wastewater on the basis of an electron beam irradiation process. The method comprises: making an RO concentrate sequentially pass through a high-dose electron beam irradiation unit, an electro-adsorption treatment unit and a low-dose electron beam irradiation unit, wherein salt substances in the RO concentrate are ionized by high-dose irradiation into hydrated electrons and oxidizing free radicals when the RO concentrate passes through the high-dose electron beam irradiation unit, thereby effectively reducing the quenching of the oxidizing free radicals, which are generated during irradiation, by the salt substances and also improving the removal of organic pollutants from the RO concentrate; when an effluent passes through the electro-adsorption treatment unit, salt ions are adsorbed and removed under the action of an electric field; and when the effluent further passes through the low-dose electron beam irradiation unit, organic pollutants therein are decomposed and removed by means of low-dose electron beam irradiation, and the effluent can be further returned to the electro-adsorption treatment unit for cyclic treatment until the COD of the effluent from the low-dose electron beam irradiation unit is less than or equal to 10 mg / L.

Description

Method and system for removing organic pollutants from reverse osmosis concentrate of coking wastewater based on electron beam irradiation process

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to a Chinese patent application filed with the Patent Office of China on January 26, 2024, with application number 202410116948.7 and entitled “Method and system for removing organic pollutants in reverse osmosis concentrate of coking wastewater based on electron beam irradiation process,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to the technical field of wastewater treatment, and in particular to a method and system for removing organic pollutants in reverse osmosis concentrated liquid of coking wastewater based on an electron beam irradiation process. Background Art

[0004] Coking wastewater is a difficult industrial wastewater to treat, characterized by its complex pollutant composition, high concentrations, and resistance to biodegradation. Biochemical treatment is one of the most widely used processes in industrial wastewater treatment. However, biological treatment processes are unable to effectively remove toxic, harmful, and recalcitrant organic pollutants in coking wastewater. This results in the treated effluent not meeting requirements for direct discharge.

[0005] In response to the above problems, deep treatment processes are usually added after biochemical treatment to improve the treatment effect. Advanced oxidation processes, such as Fenton and ozone oxidation, are one of the commonly used deep treatment processes. Although advanced oxidation processes can further reduce organic pollutants in biochemical effluent, the effluent indicators still cannot meet the requirements for reuse. In order to improve the wastewater reuse rate and achieve the goal of "zero discharge", advanced oxidation technology is often coupled with membrane processes in practice. The use of membrane processes will produce membrane concentrates. Membrane concentrates are characterized by high salt and high COD. The treatment of membrane concentrates faces the problem that the presence of high salt significantly affects the removal of organic pollutants in the membrane concentrates, resulting in the existing wastewater treatment processes having no obvious treatment effect on membrane concentrates.

[0006] Electron beam irradiation is a new advanced oxidation technology. Its primary wastewater treatment principle relies on the direct action of the electron beam (energy deposition) and the indirect action of activated water molecules to remove pollutants. Compared with traditional advanced oxidation processes, it offers advantages such as improved treatment efficiency, shorter processing times, and the elimination of the need for chemical additions. However, using electron beam irradiation alone to treat membrane concentrate typically requires a very high irradiation dose to achieve optimal treatment results due to the high salt content in the concentrate, significantly increasing treatment costs.

[0007] Therefore, how to reduce the impact of high salt in membrane concentrate on the removal of organic pollutants by electron beam irradiation, and how to recover and utilize the salt in the membrane concentrate while considering the removal of organic pollutants in the membrane concentrate, and ultimately realize the resource utilization of salt, are issues that need to be urgently addressed.

[0008] Overview

[0009] In response to the above-mentioned problems existing in the prior art, the present invention provides a method and system for removing organic pollutants in the reverse osmosis concentrated liquid of coking wastewater based on an electron beam irradiation process, which couples electron beam irradiation with electric adsorption to treat the concentrated liquid to achieve the removal of organic pollutants and the recovery of salts in the reverse osmosis concentrated liquid of coking wastewater.

[0010] The specific content of the invention is as follows:

[0011] In a first aspect, the present invention provides a method for removing organic pollutants in reverse osmosis concentrate of coking wastewater based on an electron beam irradiation process, the process comprising:

[0012] The reverse osmosis concentrate is passed through a high-dose electron beam irradiation unit, whereby some salt substances are ionized under the action of the electron beam irradiation to generate hydrated electrons and oxidative free radicals; the hydrated electrons charge some organic pollutants, and the oxidative free radicals decompose some organic pollutants, thereby obtaining primary pre-purified water;

[0013] Passing the primary pre-purified water into an electrosorption treatment unit, so that under the action of an electric field, salt ions and a portion of the charged organic pollutants in the primary purified water are removed by electrosorption; wherein H2O2 generated during the irradiation process is activated by the anode of the electrosorption treatment unit to form hydroxyl radicals, and the hydroxyl radicals decompose the organic pollutants adsorbed on the electrode surface, thereby obtaining secondary pre-purified water;

[0014] Passing the secondary pre-purified water into a low-dose electron beam irradiation unit to remove organic pollutants in the secondary pre-purified water to obtain tertiary pre-purified water;

[0015] The tertiary pre-purified water is returned to the electric adsorption treatment unit for circulation treatment until the COD of the effluent from the low-dose electron beam irradiation unit is less than or equal to 10 mg / L, thereby completing the removal of organic pollutants in the reverse osmosis concentrated liquid of the coking wastewater.

[0016] Optionally, in the reverse osmosis concentrated liquid, 150 mg / L≤COD≤500 mg / L, 10000 us / cm≤conductivity≤100000 us / cm.

[0017] Optionally, the high-dose electron beam irradiation dose is between 20 and 100 kGy.

[0018] Optionally, the water inlet flow rate of the electrosorption unit is between 1m 3 / h~20m 3 / h.

[0019] Optionally, the voltage applied by the electrosorption processing unit is between 1.2V and 1.7V.

[0020] Optionally, the anode of the electrosorption treatment unit is composed of a carbon-wrapped iron-nickel material;

[0021] The cathode of the electric adsorption treatment unit is composed of a titanium plate or a carbon material.

[0022] Optionally, the carbon-wrapped iron-nickel material includes a combination of one or more of a graphene-wrapped iron-nickel material, a biochar-wrapped iron-nickel material, a modified graphene-wrapped iron-nickel material, and a modified biochar-wrapped iron-nickel material.

[0023] Optionally, the low-dose electron beam irradiation dose is between 1 and 10 kGy.

[0024] Optionally, the cyclic treatment is repeated 1-20 times.

[0025] In a second aspect, the present invention provides a system for removing organic pollutants from reverse osmosis concentrate of coking wastewater based on electron beam irradiation, wherein the system is applicable to the method described in the first aspect above, comprising:

[0026] A high-dose electron beam irradiation unit is used to ionize salt substances in the reverse osmosis concentrated liquid into hydrated electrons and oxidative free radicals; the hydrated electrons charge a portion of organic pollutants, and the oxidative free radicals decompose a portion of organic pollutants, thereby obtaining primary pre-purified water;

[0027] an electric adsorption treatment unit for adsorbing salt ions and a portion of the charged organic pollutants in the primary pre-purified water; and activating H2O2 generated by irradiation into hydroxyl radicals, which decompose the organic pollutants adsorbed on the electrode surface, thereby obtaining secondary pre-purified water;

[0028] The low-dose electron beam irradiation unit is used to decompose organic pollutants in the secondary pre-purified water to obtain purified water.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] The present invention provides a method for removing organic pollutants from reverse osmosis concentrated liquid of coking wastewater based on an electron beam irradiation process. The method comprises the following steps: directly applying high-dose electron beam irradiation to the reverse osmosis concentrated liquid of coking wastewater to ionize the salt substances in the concentrated liquid into hydrated electrons and corresponding oxidative free radicals, thereby reducing the quenching effect of the salt substances on the active species in the water and increasing the concentration of the active species in the system, thereby increasing the removal capacity of the system for the organic pollutants in the concentrated liquid; further, the water irradiated with high-dose electron beam is subjected to electrosorption treatment, and a carbon-wrapped iron-nickel material is used as the anode material of the electrosorption treatment unit (the surface of the carbon material co-modified with iron and nickel forms obvious positive and negative charge areas, which are conducive to adsorption). In addition, there is a certain amount of H2O2 in the concentrated solution after electron beam irradiation treatment. The carbon-coated iron-nickel material can adsorb H2O2 very well and activate it into hydroxyl radicals. The hydroxyl radicals are used to remove organic pollutants adsorbed on the electrode surface, which can further remove organic pollutants in the concentrated solution. The low-concentration organic pollutants remaining in the concentrated solution after electro-adsorption treatment are further decomposed and removed under the action of low-dose electron beam irradiation. If the effluent COD is greater than 10 mg / L, the effluent can be returned to the electro-adsorption treatment unit and circulated through the electro-adsorption treatment unit and the low-dose electron beam irradiation unit until the effluent COD is less than 10 mg / L.

[0031] The present invention provides a method for removing organic pollutants from reverse osmosis concentrate of coking wastewater based on electron beam irradiation. The method is simple to operate and does not require the addition of chemical substances. While reducing the organic pollutants in the membrane concentrate, it is also conducive to the recovery and utilization of salt. The method has broad application prospects in the field of RO concentrated water treatment of coking wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or related technologies, the following is a brief introduction to the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0033] FIG1 shows a flow chart of a method for removing organic pollutants from reverse osmosis concentrate of coking wastewater based on an electron beam irradiation process according to an embodiment of the present invention;

[0034] FIG2 shows a schematic diagram of the structure of a system for removing organic pollutants in reverse osmosis concentrate of coking wastewater based on an electron beam irradiation process provided by an embodiment of the present invention. Specific embodiments

[0035] The following examples are provided for a better understanding of the present invention and are not intended to limit the best mode of implementation. They do not limit the content and scope of protection of the present invention. Any product identical or similar to the present invention obtained by anyone under the guidance of the present invention or by combining the features of the present invention with other prior arts shall fall within the scope of protection of the present invention.

[0036] If no specific experimental steps or conditions are specified in the examples, the experiments can be carried out according to the conventional experimental steps or conditions described in the prior art. The reagents and other instruments used, if the manufacturers are not specified, are all commercially available conventional reagents.

[0037] Current research and practical applications primarily rely on the indirect effects of electron beam irradiation for wastewater treatment, without considering its direct effects. Furthermore, when the concentration of organic pollutants in the concentrate is low, the presence of salts far outweighs the concentration of organic pollutants. This causes the active species produced during electron beam irradiation to react more with the salts, making it ineffective in removing low-concentration organic pollutants. Using electron beam irradiation alone to remove low-concentration organic pollutants in the concentrate typically requires a significantly higher irradiation dose than theoretically required, significantly increasing treatment costs.

[0038] Electrosorption uses an electric field to cause ions in water to migrate toward oppositely charged electrodes, where they are adsorbed and stored within the double layer. Research has shown that electrosorption can separate salt and water. However, it cannot remove organic pollutants from water. Furthermore, the choice of electrode material is crucial for electrosorption separation of salt and water.

[0039] Based on the above considerations, the present invention aims to achieve the removal of organic pollutants in the reverse osmosis concentrate of coking wastewater by coupling electron beam irradiation with electrosorption. The specific implementation content is as follows:

[0040] In a first aspect, the present invention provides a method for removing organic pollutants from a reverse osmosis concentrate of coking wastewater based on an electron beam irradiation process. FIG1 shows a flow chart of a method for removing organic pollutants from a reverse osmosis concentrate of coking wastewater based on an electron beam irradiation process according to an embodiment of the present invention. As shown in FIG1 , the method comprises:

[0041] S1. Passing the reverse osmosis concentrate into a high-dose electron beam irradiation unit, whereby some salt substances are ionized under the action of the electron beam to generate hydrated electrons and oxidative free radicals; the hydrated electrons charge some organic pollutants, and the oxidative free radicals decompose some organic pollutants, thereby obtaining primary pre-purified water;

[0042] S2. Passing the primary pre-purified water into an electro-adsorption treatment unit, so that under the action of an electric field, salt ions and a portion of charged organic pollutants in the primary purified water are electro-adsorbed and removed; wherein H2O2 generated during the irradiation process is activated by the anode of the electro-adsorption treatment unit into hydroxyl radicals, which decompose the organic pollutants adsorbed on the electrode surface, thereby obtaining secondary pre-purified water;

[0043] S3, passing the secondary pre-purified water into a low-dose electron beam irradiation unit to remove organic pollutants in the secondary pre-purified water to obtain tertiary pre-purified water;

[0044] S4. Return the tertiary pre-purified water to the electric adsorption treatment unit for circulation treatment until the COD in the effluent of the low-dose electron beam irradiation unit is ≤10 mg / L, thereby completing the removal of organic pollutants in the reverse osmosis concentrate of the coking wastewater.

[0045] In specific implementation, the embodiment of the present invention utilizes the direct effect of high-dose electron beam irradiation to directly ionize some salt substances, generating corresponding hydrated electrons and oxidative free radicals, wherein the oxidative free radicals include but are not limited to O2· - 、Cl·、SO4 - The conversion of salts reduces their quenching effect on active species, while the generated active species can also enhance the oxidation capacity of organic pollutants in the concentrate. The high-dose electron beam irradiation dose ranges from 20 to 100 kGy. Furthermore, the electron beam irradiation process also generates hydrated electrons, which charge the originally neutral organic pollutants, thereby enabling electrosorption to remove some organic pollutants from the concentrate.

[0046] When the dose of electron beam irradiation acting on the RO concentrate is between 20 and 100 kGy, some salt substances in the concentrate are ionized and decomposed, and some organic pollutants are decomposed under the action of the ionization products. Further electrosorption means are used to separate the remaining salt substances and water. The voltage applied during the electrosorption process is between 1.2 and 1.7 V. In addition, the present invention uses carbon-wrapped iron-nickel material as the positive electrode material of the electrosorption treatment unit, which has a good adsorption effect on H2O2 generated during the electron beam irradiation process and activates it into hydroxyl radicals. Hydroxyl radicals can be used to remove organic pollutants adsorbed on the electrode surface, improve the purity of salt substances adsorbed by the electrode material, and improve the recovery value of salt substances.

[0047] After treatment by the electro-adsorption unit, any remaining low-concentration organic pollutants in the effluent can be removed by low-dose electron beam irradiation at the rear end. If the COD of the effluent after low-dose electron beam irradiation is greater than 10 mg / L, the effluent can be returned to the electro-adsorption unit and circulated through the electro-adsorption unit and low-dose electron beam irradiation unit until the effluent COD is less than 10 mg / L. Through the synergistic effect of electron beam irradiation and electro-adsorption, the present invention can effectively remove organic pollutants from the membrane concentrate, ultimately achieving resource utilization of experimental salt.

[0048] In practice, high-dose electron beam irradiation directly ionizes a portion of the salts in the RO concentrate into hydrated electrons and oxidative free radicals. The remaining salts are then removed by the electrosorption treatment unit. Therefore, the present invention can treat high-salt coking wastewater reverse osmosis concentrate, where the salt content, expressed as solution conductivity, can reach a maximum of 100,000 µs / cm and a minimum of no less than 10,000 µs / cm. Furthermore, the treatment process provided by the present invention is suitable for RO concentrates with organic matter concentrations ranging from 150 mg / L to ≤ COD and from ≤ 500 mg / L.

[0049] In some embodiments, the anode of the electrosorption treatment unit is composed of a carbon-wrapped iron-nickel material; the cathode of the electrosorption treatment unit is composed of a titanium plate or a carbon material. Preferred carbon-wrapped iron-nickel materials include: a combination of one or more of a graphene-wrapped iron-nickel material, a biochar-wrapped iron-nickel material, a modified graphene-wrapped iron-nickel material, and a modified biochar-wrapped iron-nickel material. Since H2O2 is generated during the electron beam irradiation process, the carbon-wrapped iron-nickel material is used as an electrode anode for electrosorption. The iron-nickel modification increases the active sites on the electrode surface, enhances its ability to adsorb salts in sewage, and also reduces the energy barrier required for the activation of H2O2 (oxidant) present in the system, activating H2O2 into hydroxyl radicals. Hydroxyl radicals can remove organic pollutants adsorbed on the electrode surface, improve the purity of salt substances adsorbed by the electrode material, and thereby increase the recovery value of the salt substances. In addition, the addition of thiourea introduces sulfur and nitrogen into the electrode material at the same time. Sulfur is a multivalent element with abundant electrons, which can enhance the electron transfer and electron exchange capabilities of the electrode material, thereby further promoting the activation of the adsorbed oxidant. This allows the electrode material to not only possess excellent salt separation properties but also the ability to adsorb and activate oxidants. The presence of nitrogen allows the iron and nickel in the composite material to complex with nitrogen, forming a more stable structure, effectively preventing material loss or failure caused by the dissolution of iron and nickel during actual use.

[0050] In some embodiments, a biochar-coated iron-nickel material can be prepared by the following method: 20 ml of a 0.1 M potassium ferricyanide solution is dropwise added to 20 ml of a 0.15 M solution. After aging in air for 12 hours, the mixture is filtered and washed three times with deionized water to obtain a Prussian blue analog. The mixture is then dried in a 60°C oven for 12 hours. 0.5 g of the dried Prussian blue solid and 1.5 g of chitosan are placed in 50 ml of deionized water, sonicated for 10 minutes, stirred for 1 hour, and then dried in an 80°C oven for 12 hours. 1 g of the dried solid is mixed with 10 g of thiourea solid and ground until uniform. The ground powder is placed in a tube furnace. Under nitrogen, the temperature is increased at 3°C / min to 550°C and held for 1 hour, then increased at 5°C / min to 900°C and held for 1 hour. After cooling naturally, the resulting solid is washed three times with deionized water and dried in a 60°C oven. The resulting solid is the carbon-coated iron-nickel material.

[0051] In some embodiments, a graphene-wrapped iron-nickel material can be prepared by the following preparation method: 20 ml of a 0.1 M potassium ferricyanide solution is dropwise added to 20 ml of a 0.2 M solution. After aging in air for 10 hours, the mixture is filtered and washed three times with deionized water to obtain a Prussian blue analog. The mixture is then dried in an 80°C oven for 12 hours. 0.5 g of the dried Prussian blue solid and 2 g of the modified graphene are placed in 50 ml of deionized water, sonicated for 10 minutes, stirred for 1 hour, and then dried in an 80°C oven for 12 hours. 1 g of the dried solid is mixed with 15 g of thiourea solid and ground uniformly. The ground powder is placed in a tube furnace. Under nitrogen, the temperature is increased at 3°C / min to 550°C and held for 1 hour, then increased at 5°C / min to 900°C and held for 1 hour. After cooling naturally, the resulting solid is washed three times with deionized water and dried in a 60°C oven. The resulting solid is the carbon-wrapped iron-nickel material.

[0052] In some embodiments, the tertiary pre-purified water is returned to the electric adsorption treatment unit for 5-20 cycles, and the COD in the effluent is ≤10 mg / L.

[0053] In a second aspect, the present invention provides a system for removing organic pollutants from reverse osmosis concentrate of coking wastewater based on an electron beam irradiation process. The system is applicable to the method described in the first aspect above. FIG2 shows a schematic structural diagram of a system for removing organic pollutants from reverse osmosis concentrate of coking wastewater based on an electron beam irradiation process provided by an embodiment of the present invention. As shown in FIG2 , the system comprises:

[0054] The high-dose electron beam irradiation unit is used to ionize the salt substances in the reverse osmosis concentrate into hydrated electrons and oxidative free radicals; the hydrated electrons charge some organic pollutants, and the oxidative free radicals decompose some organic pollutants, thereby obtaining primary pre-purified water;

[0055] The electro-adsorption treatment unit is used to adsorb salt ions and some charged organic pollutants in the primary pre-purified water; and activate the H2O2 generated by irradiation into hydroxyl radicals, which decompose the organic pollutants adsorbed on the electrode surface, thereby obtaining secondary pre-purified water;

[0056] The low-dose electron beam irradiation unit is used to decompose organic pollutants in the secondary pre-purified water to obtain purified water.

[0057] In order to enable those skilled in the art to more clearly understand the present invention, the method and system for removing organic pollutants in reverse osmosis concentrate of coking wastewater based on electron beam irradiation process according to the present invention are described in detail through the following examples.

[0058] The specific treatment method for coking wastewater is as follows: RO concentrated water first passes through the first electron beam irradiation treatment unit (high-dose electron beam irradiation unit), the effluent enters the electric adsorption treatment unit, and finally enters the second electron beam irradiation treatment unit (low-dose electron beam irradiation unit). The effluent is directly discharged (COD in the effluent is less than 10 mg / L), or returns to the electric adsorption treatment unit for multiple cycles. After the effluent COD of the low-dose electron beam irradiation unit is less than 10 mg / L, it is discharged, and the treatment of the membrane concentrate is finally completed.

[0059] Example 1

[0060] Take the RO concentrate from a coking plant in Hebei Province, with an initial COD of 247 mg / L and a conductivity of 17500 μs / cm. The anode of the electrosorption unit is iron-nickel modified coconut shell carbon, the cathode is a titanium plate, and the flow rate is 1m 3 / h. The electron beam irradiation dose in the first stage is 30kGy, and the electron beam irradiation dose in the second stage is 5kGy. After three cycles of treatment, the effluent COD is less than 10mg / L.

[0061] Example 2

[0062] Take the RO concentrate from a coking plant in Hebei Province, with an initial COD of 247 mg / L and a conductivity of 17500 μs / cm. The anode of the electrosorption unit is iron-nickel modified coconut shell carbon, the cathode is a titanium plate, and the flow rate is 1m 3 / h. The electron beam irradiation dose in the first stage is 50kGy, and the electron beam irradiation dose in the second stage is 10kGy. After two cycles of treatment, the effluent COD is less than 10mg / L.

[0063] Example 3

[0064] Take the RO concentrate from a coking plant in Hebei Province, with an initial COD of 376 mg / L and a conductivity of 77500 μs / cm. The anode of the electrosorption unit is iron-nickel modified coconut shell carbon, the cathode is a titanium plate, and the flow rate is 1m 3 / h. The electron beam irradiation dose in the first stage is 70kGy, and the electron beam irradiation dose in the second stage is 10kGy. After 6 cycles of treatment, the effluent COD is less than 10mg / L.

[0065] Comparative Example 1

[0066] RO concentrate from a coking plant in Hebei Province had an initial COD of 247 mg / L and a conductivity of 17,500 μs / cm. It was treated with a single electron beam irradiation dose of 150 kGy, resulting in a effluent COD of 134 mg / L.

[0067] Comparative Example 2

[0068] RO concentrate from a coking plant in Hebei Province had an initial COD of 376 mg / L and a conductivity of 77,500 μs / cm. It was treated with a single electron beam irradiation dose of 150 kGy, resulting in a effluent COD of 277 mg / L.

[0069] As can be seen from the above examples, electron beam irradiation coupled with electrosorption can effectively reduce the impact of high salt concentrations. Since no chemicals are added during the entire treatment process, the final salt purity is relatively high. Therefore, electron beam irradiation coupled with electrosorption offers the advantages of simple operation, excellent treatment results, and high salt purity.

[0070] References herein to "one embodiment," "an embodiment," or "one or more embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Furthermore, please note that instances of the phrase "in one embodiment" do not necessarily all refer to the same embodiment.

[0071] In the description provided herein, numerous specific details are described. However, it is understood that embodiments of the present disclosure may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0072] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in the claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present disclosure may be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third etc. does not indicate any order. These words may be interpreted as names.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present disclosure.

Claims

1. A method for removing organic pollutants in the reverse osmosis concentrate of coking wastewater based on an electron beam irradiation process, characterized in that, The process includes: Feeding the reverse osmosis concentrate into a high-dose electron beam irradiation unit, where some salt substances are ionized under the action of electron beam irradiation to generate hydrated electrons and oxidizing free radicals; the hydrated electrons charge some organic pollutants, and the oxidizing free radicals decompose some organic pollutants, thereby obtaining primary pre-purified water; Feeding the primary pre-purified water into an electro-adsorption treatment unit, so that under the action of an electric field, the salt ions and some of the charged organic pollutants in the primary purified water are removed by electro-adsorption; H2O2 generated during the irradiation process is activated by the anode of the electro-adsorption treatment unit into hydroxyl free radicals, and the hydroxyl free radicals decompose the organic pollutants adsorbed on the electrode surface, thereby obtaining secondary pre-purified water; Feeding the secondary pre-purified water into a low-dose electron beam irradiation unit to remove organic pollutants in the secondary pre-purified water and obtain tertiary pre-purified water; Returning the tertiary pre-purified water to the electro-adsorption treatment unit for cyclic treatment until the COD in the effluent of the low-dose electron beam irradiation unit is ≤ 10 mg / L, at which point the removal of organic pollutants in the reverse osmosis concentrate of coking wastewater is completed.

2. The method according to claim 1, characterized in that In the reverse osmosis concentrate, 150 mg / L ≤ COD ≤ 500 mg / L, and 10000 μs / cm ≤ conductivity ≤ 100000 μs / cm.

3. The processing technology according to claim 1, characterized in that, The high-dose electron beam irradiation dose ranges from 20 to 100 kGy.

4. The method according to claim 1, wherein The influent flow rate of the electro-adsorption unit is between 1 m 3 / h and 20 m 3 / h.

5. The method according to claim 1, wherein The voltage applied to the electro-adsorption treatment unit ranges from 1.2 to 1.7 V.

6. The method according to claim 1, wherein The anode of the electro-adsorption treatment unit is composed of carbon-coated iron-nickel material; The cathode of the electro-adsorption treatment unit is composed of a titanium plate or a carbon material.

7. The method according to claim 6, characterized in that, The carbon-coated iron-nickel material includes one or a combination of more of graphene-coated iron-nickel material, biochar-coated iron-nickel material, modified graphene-coated iron-nickel material, and modified biochar-coated iron-nickel material.

8. The method according to claim 1, wherein The low-dose electron beam irradiation dose ranges from 1 to 10 kGy.

9. The method according to claim 1, wherein The number of cyclic treatments is 1 - 20 times.

10. A system for treating organic pollutants in the reverse osmosis concentrate of coking wastewater based on an electron beam irradiation process, characterized in that, The system is applicable to the method described in any one of claims 1 - 9 above, and includes: A high-dose electron beam irradiation unit for ionizing salt substances in the reverse osmosis concentrate into hydrated electrons and oxidizing free radicals; the hydrated electrons charge some organic pollutants, and the oxidizing free radicals decompose some organic pollutants, thereby obtaining primary pre-purified water; An electro-adsorption treatment unit for adsorbing salt ions and some of the charged organic pollutants in the primary pre-purified water; and activating H2O2 generated by irradiation into hydroxyl free radicals, and the hydroxyl free radicals decompose the organic pollutants adsorbed on the electrode surface, thereby obtaining secondary pre-purified water; A low-dose electron beam irradiation unit for decomposing organic pollutants in the secondary pre-purified water to obtain purified water.

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