Apparatus and method for ionizing radiation treatment of sewage

Abstract

This invention relates to the field of wastewater treatment, specifically to an apparatus and method for treating wastewater using ionizing radiation. A wastewater treatment apparatus includes: a container for holding wastewater; a spraying component located on the side wall of the container for spraying the wastewater to be treated into the container in a parabolic manner; an electron beam irradiation component for generating an electron beam, which irradiates the parabolic surface of the wastewater to be treated; and a catalyst supporting component for supporting a catalyst; the catalyst supporting component is located in the middle and / or bottom of the container, such that the catalyst is in contact with the parabolic surface and / or with the wastewater at the bottom of the container. The apparatus and method for treating wastewater using ionizing radiation of this invention can significantly alter the absorbed dose distribution in wastewater, improve electron beam energy utilization, while maintaining the degradation rate of pollutants.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, and more specifically to an apparatus and method for treating wastewater by ionizing radiation. Background Technology

[0002] Electron beam irradiation is a novel wastewater treatment technology. It rapidly generates hydroxyl radicals, causing long-chain organic compounds to break down or benzene rings to degrade some organic pollutants directly. This process is indiscriminate in its effect on long-chain organic compounds, resulting in highly efficient wastewater treatment with excellent results, thus overcoming some of the bottlenecks of traditional processes.

[0003] Currently, the application of ionizing radiation wastewater treatment technology in industry is limited, mainly focusing on adding consumable reagents to the ionizing radiation process and coupling and integrating it with other traditional processes. No methods specifically designed to improve electron beam utilization by modifying the beam-down apparatus have been reported.

[0004] Therefore, the discovery of an apparatus and method for treating industrial wastewater with ionizing radiation to improve the energy efficiency of electron beam irradiation is of great significance to the field of wastewater treatment. Summary of the Invention

[0005] The purpose of this invention is to overcome the aforementioned problems in the prior art and provide an apparatus and method for treating wastewater using ionizing radiation. The apparatus and method for treating wastewater using ionizing radiation of this invention can significantly alter the absorbed dose distribution in wastewater, improve electron beam energy utilization, and simultaneously maintain the degradation rate of pollutants.

[0006] A first aspect of the present invention provides a wastewater treatment apparatus, comprising: a container for holding wastewater; a spraying component located on a side wall of the container for spraying the wastewater to be treated into the container in a parabolic manner; an electron beam irradiation component for generating an electron beam, and the electron beam irradiating the parabolic surface of the wastewater to be treated; and a catalyst carrying component for carrying a catalyst; the catalyst carrying component being located in the middle and / or bottom of the container such that the catalyst contacts the parabolic surface and / or contacts the wastewater at the bottom of the container.

[0007] A second aspect of the present invention provides a method for wastewater treatment, performed in the apparatus provided in the first aspect of the present invention. The method includes: the wastewater to be treated is ejected in a parabolic shape through a spraying component, and falls into a container after being irradiated by an electron beam emitted by an electron beam irradiation component; the wastewater to be treated comes into contact with a catalyst on a catalyst support component while being irradiated by the electron beam, and / or the wastewater to be treated comes into contact with a catalyst on a catalyst support component at the bottom of the container.

[0008] By employing the above technical solution, the present invention has at least the following advantages compared with the prior art:

[0009] (1) The apparatus and method for treating wastewater by ionizing radiation of the present invention can significantly change the absorbed dose distribution in wastewater, thereby utilizing almost all the electron beam energy.

[0010] (2) The ionizing radiation wastewater treatment apparatus and method of the present invention can effectively degrade high-concentration, difficult-to-degrade, long-chain high-molecular organic compounds in wastewater, thereby greatly improving the efficiency of wastewater treatment.

[0011] (3) The ionizing radiation wastewater treatment device and method of the present invention can be combined with various wastewater treatment operation modes, such as Fenton, ozone catalytic oxidation, membrane filtration, flocculation, reverse osmosis, etc.; however, in reality, the ionizing radiation wastewater treatment device and method of the present invention can achieve satisfactory water treatment effect by simply combining the ionizing catalytic unit with a conventional biochemical unit.

[0012] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. Attached Figure Description

[0013] Figure 1 The diagram shown is a schematic diagram of a device according to an embodiment of the present invention;

[0014] Figure 2 The figure shows the absorbed dose distribution in wastewater under single electron beam irradiation;

[0015] Figure 3 The figure shows the absorbed dose distribution of the electron beam in wastewater in one embodiment of the present invention;

[0016] Figure 4 The figure shows the total absorbed dose distribution of the electron beam in wastewater in one embodiment of the invention (Region I - energy currently used for electron beam irradiation, Region II - energy used for electron beam irradiation as added by the present invention).

[0017] Figure 5 The diagram shown is a schematic diagram of the injection port of the injection component according to an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures

[0019] 1-Wastewater, 2-Spraying component, 3-Water film, 4-Container, 5-Discharge port, 6-Electron beam. Detailed Implementation

[0020] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0021] The inventors of this invention have discovered the following problems with electron beam irradiation technology: On the one hand, the absorbed dose of electron beam irradiation in wastewater decreases with the depth of incidence (e.g., Figure 2 (As shown in the image). On the other hand, the degradation rate of organic pollutants in wastewater is positively correlated with the electron beam absorbed dose. Therefore, in order to achieve a certain standard of degradation effect, the electron beam absorbed dose needs to exceed a certain threshold, which means that only the first half of the incident electron beam energy can be utilized. The electron beam energy in the latter half is wasted, which increases energy consumption. At the same time, the remaining electron beam energy causes radiation-induced damage such as material heating, increasing the material loss rate. Moreover, additional shielding measures are required to protect against the radiation caused by the remaining electron beam energy.

[0022] The first aspect of the present invention provides a wastewater treatment device (such as...) Figure 1 As shown, the container 4 includes: a spraying component 2 located on the side wall of the container for spraying the wastewater 1 to be treated into the container in a parabolic manner; an electron beam irradiation component for generating an electron beam 6, and the electron beam 6 irradiating the parabolic surface 3 of the wastewater to be treated; and a catalyst support component for supporting a catalyst. The catalyst support component is located in the middle and / or bottom of the container so that the catalyst is in contact with the parabolic surface and / or with the wastewater at the bottom of the container.

[0023] The container is also provided with a discharge port 5 at the bottom.

[0024] The steps of electron beam irradiation of the wastewater and contacting the wastewater with the catalyst can be performed simultaneously or sequentially with time intervals. When performed sequentially with time intervals, the time interval is ≤1 min, preferably ≤30 s, and more preferably ≤10 s.

[0025] The contact method between the catalyst support component and the wastewater is not limited. The catalyst support component may already exist in the wastewater; alternatively, the wastewater may first be irradiated by an electron beam irradiation device and then flow through a flow path containing the catalyst support component.

[0026] In one instance, the catalyst support component may already be present in the wastewater.

[0027] The electron beam irradiation component includes an electron accelerator and a beam exit port.

[0028] In one example, the electron beam irradiation component includes two or more beam exits, such that the electron beam irradiation component emits two or more electron beams in different directions.

[0029] The emitted electron beam can be emitted by one electron accelerator and then split into two beams through two exit ports; or it can be emitted by two electron accelerators and then each of them passes through two exit ports.

[0030] In one example, the electron beam irradiation component emits at least a pair of opposing first and second electron beams, wherein the first electron beam irradiates the bottom surface of the container from top to bottom, and the second electron beam irradiates the top surface of the container from bottom to top, with the exit points of the first and second electron beams located on opposite sides of the parabolic surface.

[0031] The top and bottom surfaces of the container and the parabolic surface of the wastewater are substantially parallel. When the first electron beam shines down onto the bottom surface of the container and the second electron beam shines up onto the top surface of the container, the first electron beam and the second electron beam shine down onto the parabolic surface of the wastewater to be treated, respectively.

[0032] This invention designs electron beam exit ports that are positioned vertically opposite each other, resulting in a more uniform distribution of the total absorbed dose of the two electron beams in the wastewater (e.g., Figure 3 and Figure 4 (as shown) Figure 4 Region I represents the energy currently utilized by electron beam irradiation, while Region II represents the energy utilized by electron beam irradiation as added in this invention. By adjusting the flow rate of the wastewater, a more uniform absorbed dose distribution can be obtained over a wider penetration depth range, thereby effectively improving the energy utilization efficiency of the electron beam.

[0033] The incident directions of the first electron beam and the second electron beam are at a certain angle to the parabolic surface, such as an acute angle or a right angle.

[0034] In one example, the first electron beam and the second electron beam irradiate both sides of the parabola perpendicularly. For example... Figure 1 The electron beam 6 shown is incident in a direction parallel to the plane of the paper, and the parabolic plane is perpendicular to the plane of the paper.

[0035] The length of the nozzle ( Figure 5 L in the equation is related to the scanning width of the electron beam. Figure 5 Matching (a) in the above, the width of the nozzle ( Figure 5 The value of W depends on the energy of the electron beam.

[0036] That is, the length of the nozzle is the same as the scanning width of the electron beam, and the width of the nozzle is determined according to the penetrating power of the electron beam energy.

[0037] In general, to improve the utilization rate of the electron beam energy, the water film is relatively thin, so the nozzle has a large aspect ratio.

[0038] In one example, the length of the nozzle outlet is 50cm-200cm (e.g., 50cm, 80cm, 100cm, 120cm, 150cm, 180cm, 200cm), the width is 0.5cm-5cm (e.g., 0.5cm, 1cm, 2cm, 3cm, 4cm, 5cm), and the length-to-width ratio is (25-400):1 (e.g., 25:1, 50:1, 100:1, 150:1, 200:1, 250:1, 300:1, 350:1, 400:1).

[0039] Preferably, the nozzle has a length of 80cm-150cm and a width of 0.5cm-3cm.

[0040] A second aspect of the present invention provides a method for wastewater treatment, performed within the apparatus provided in the first aspect of the present invention, the method comprising:

[0041] The wastewater to be treated 1 is ejected in a parabolic shape 3 through the spraying component 2, and falls into the container 4 after being irradiated by the electron beam 6 emitted by the electron beam irradiation component; the wastewater to be treated comes into contact with the catalyst on the catalyst support component while being irradiated by the electron beam, and / or the wastewater to be treated comes into contact with the catalyst on the catalyst support component at the bottom of the container.

[0042] The wastewater is irradiated by electron beam 6 and then flows out from outlet 5 to enter subsequent treatment steps.

[0043] The inventors of this invention discovered that when the thickness of the water film on the parabolic surface and the flow rate of the sewage are set according to the following formula, the optimal electron beam energy utilization rate can be achieved when the first electron beam and the second electron beam are irradiated relative to each other.

[0044] In one example, the thickness of the water film on the parabolic surface conforms to Formula 1, i.e., h = 9 × 10⁻⁶. -9 E-0.005.

[0045] Where E is the average energy in eV; h is the required water film thickness for the reactor under the wastewater jet in meters.

[0046] By coordinating two electron beams, the optimized water film thickness is exposed to the appropriate irradiation energy, maximizing efficiency. With the same energy consumption, more wastewater can be treated in a shorter time.

[0047] In one instance, the wastewater flow velocity conforms to Formula 2, i.e., v = IE / (2000xelh).

[0048] Where I is the average beam current intensity of the electron beam, in A; l is the width of the parabolic water film of the wastewater to be treated, in m; v is the wastewater flow velocity, in m / s; x is the absorbed dose required for the wastewater to meet the discharge standards, in Gy; E is the average energy, in eV; and e is the electron charge, a constant 1.6 × 10⁻⁶. -19 C. It should be noted that the unit eV of E also contains e, so the e can be removed from the unit eV of E. For example, when the average energy of the electron beam is 1MeV, E / e is 1M.

[0049] The value of x is determined based on factors such as water quality. Those skilled in the art can determine the specific value of x based on the degradation load of the pollutants by the electron beam irradiation unit. In common wastewater, x typically ranges from 0.5 kGy to 10 kGy.

[0050] The energy and intensity of the electron beam determine its effectiveness in degrading pollutants. The higher the energy of the electron beam, the stronger its penetration in wastewater and the more fully it interacts with the pollutants; the greater the intensity of the electron beam, the more electrons are available for pollutant degradation, and the higher the corresponding degradation efficiency.

[0051] It is generally believed that water flow velocity is related to treatment efficiency; slower flow results in better treatment efficiency but lower treatment volume and higher cost, while faster flow results in poorer treatment efficiency but higher treatment volume. The inventors of this invention have discovered that by using a formula, the water flow velocity can be controlled to a precise level, ensuring that all wastewater is effectively treated, thereby achieving a larger treatment volume and lower cost while maintaining treatment efficiency.

[0052] In one example, the energy of the electron beam is 0.5-15 MeV (e.g., 0.5 MeV, 1 MeV, 2 MeV, 3 MeV, 4 MeV, 5 MeV, 6 MeV, 7 MeV, 8 MeV, 9 MeV, 10 MeV, 11 MeV, 12 MeV, 13 MeV, 14 MeV, 15 MeV).

[0053] In one instance, the energy of the electron beam is 2.5-10.0 MeV.

[0054] In one example, the beam current intensity of the electron beam is 1-300mA (e.g., 1mA, 2mA, 3mA, 4mA, 5mA, 10mA, 20mA, 30mA, 40mA, 50mA, 100mA, 200mA, 300mA).

[0055] In one example, the thickness of the water film penetrated by the electron beam is 0.5-5 cm (e.g., 0.5 cm, 1 cm, 1.5 cm, 2 cm, 2.5 cm, 3 cm, 3.5 cm, 4 cm, 4.5 cm, 5 cm).

[0056] The term "penetrating water film thickness" refers to the thickness of the water film that the electron beam energy can penetrate.

[0057] In one example, the energy difference between the first electron beam and the second electron beam is within 50%, and the beam current difference between the first electron beam and the second electron beam is within 30%.

[0058] In one example, the energy difference between the first electron beam and the second electron beam is within 20%, and the beam current difference between the first electron beam and the second electron beam is within 20%.

[0059] In one example, the energy difference between the first electron beam and the second electron beam is within 10%, and the beam current difference between the first electron beam and the second electron beam is within 10%.

[0060] In one instance, the first and second electron beams have the same energy and the same beam current intensity.

[0061] The method for treating wastewater with ionizing radiation in this invention, when used in conjunction with a catalyst, can more effectively remove pollutants from the wastewater.

[0062] In one example, the catalyst comprises an active metal element and an optional support, the active metal element being selected from one or more alkaline earth metals and transition metals, the active metal element existing in an insoluble solid form.

[0063] In one example, the catalyst is a catalyst that synergistically degrades high molecular weight organic compounds with electron beam irradiation.

[0064] In one instance, the wastewater is wastewater containing high molecular weight organic compounds.

[0065] The apparatus and method for treating wastewater by ionizing radiation in this invention are particularly suitable for treating wastewater containing high molecular weight organic compounds.

[0066] The scope of application of this invention is not particularly limited to the range of "high molecular weight organic compounds." It has a catalytic degradation effect on various high molecular weight organic compounds, such as some organic compounds commonly found in wastewater with high COD. The molecular weight of the term "high molecular weight" is not particularly limited, but from the perspective of the catalytic function of this invention, any organic compound that can be degraded or needs to be degraded can be understood as "high molecular weight," for example, a molecular weight of 5 kDa or higher.

[0067] In this invention, the catalyst is combined with an electron beam to further enhance the effectiveness of the catalyst and electron beam irradiation in degrading high-molecular-weight organic compounds, making high-concentration, recalcitrant, and long-chain high-molecular-weight organic compounds easier to degrade.

[0068] The ionizing radiation wastewater treatment apparatus and method of the present invention can be combined with a coarse filtration unit, a biochemical unit, a fine filtration unit, etc., to finally obtain qualified wastewater.

[0069] In this invention, the terms "first," "second," "bottom surface," "top surface," etc., are used to distinguish similar objects, not to describe a specific order or sequence.

[0070] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0071] The water quality indicators of the wastewater to be treated used in the examples are shown in Table 1. In addition, Table 1 also includes the classification indicators specified in GB18918-2002 "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants".

[0072] Table 1

[0073]

[0074] In the following examples and comparative examples, the theoretical water film thickness is determined by Formula 1, i.e., h = 9 × 10⁻⁶. -9 The value is calculated as E-0.005, where E is the average energy in eV; h is the required design water film thickness for the reactor under the wastewater jet in meters. The actual water film thickness is the thickness obtained from actual measurement.

[0075] The theoretical wastewater flow velocity is calculated using formula 2, v = IE / (2000xelh), where I is the average beam current intensity of the electron beam (A); l is the width of the parabolic water film of the wastewater to be treated (m); v is the wastewater flow velocity (m / s); x is the absorbed dose required for the wastewater to meet discharge standards (Gy); E is the average energy (eV); and e is the electron charge. The actual wastewater flow velocity is the wastewater flow velocity obtained through actual measurement.

[0076] Example 1

[0077] The wastewater from dyeing and printing to be treated undergoes the following steps in sequence:

[0078] (1) Coarse filtration unit: Add polymer to the wastewater, aerate it, and then enter the sludge-water separation device to remove solids;

[0079] (2) Biochemical unit: aerobic biochemical reactor, which is equipped with enzyme floating packing material and has a residence time of 2 hours;

[0080] (3) Ionization irradiation catalytic unit: An electron accelerator is used to irradiate from two outlets from top to bottom and from bottom to top respectively. Wastewater is sprayed out in a parabolic shape through the spraying component and falls into the container after being irradiated by the electron beam. The gel loaded with multi-metal catalyst is dispersed in the wastewater. The solid gel component is then filtered.

[0081] The energy and beam intensity of the two beam outlets are the same, specifically: energy of 10 MeV, beam intensity of 2 mA, and beam scanning width of 80 cm; the theoretical water film thickness is calculated to be 8.5 cm, and the actual water film thickness is adjusted to 8.5 cm; the absorbed dose x required for the wastewater to reach the discharge standard is 0.5 kGy (x in the following examples is the same as in Example 1 because the same wastewater is used); the theoretical wastewater flow velocity is calculated to be 0.3 m / s, and the water flow velocity is adjusted to be the same as the theoretical wastewater flow velocity;

[0082] (4) Biochemical unit: facultative / aerobic biochemical reactor, which is equipped with enzyme floating packing material and has a residence time of 10 hours;

[0083] (5) Fine filtration unit: Residual pollutants are removed by activated sand filtration, and the water from the outlet of the fine filtration unit is collected for testing.

[0084] Example 2

[0085] The procedure is carried out in accordance with Example 1, except that the parameters of the two beam exits are changed (the parameters of the two beam exits are the same). Specifically, the energy is 2.5 MeV, the beam intensity is 20 mA, and the beam scanning width is 80 cm.

[0086] The theoretical water film thickness was calculated to be 1.8 cm, and the actual water film thickness was set to 1.8 cm; the theoretical sewage flow velocity was calculated to be 3.6 m / s, and the water flow velocity was adjusted to be the same as the theoretical sewage flow velocity.

[0087] Example 3

[0088] The same procedure was followed as in Example 1, except that the actual water film thickness was adjusted to 4 cm, which is significantly different from the theoretical water film thickness.

[0089] Example 4

[0090] The procedure was carried out in accordance with Example 1, except that the actual water flow velocity was adjusted to 1 m / s, which is significantly different from the theoretical water flow velocity.

[0091] Example 5

[0092] The procedure is carried out in accordance with Example 1, except that in step (3), the ionization irradiation catalytic unit uses a single outlet to irradiate from top to bottom, while the outlet parameters remain unchanged.

[0093] Example 6

[0094] The procedure was carried out in accordance with Example 1, except that a commercially available process was used for single-sided irradiation, resulting in a thinner water film and utilizing only the higher-energy portion of the electron beam. The water film thickness was 4 cm. The throughput of Example 1 was achieved by increasing the flow rate to 0.625 m / s.

[0095] Comparative Example 1

[0096] The procedure was carried out in accordance with Example 1, except that step (3) of ionizing the catalytic unit was omitted.

[0097] The treated water obtained in the above embodiments was subjected to water quality testing, and the results are summarized in Table 2.

[0098] Table 2

[0099]

[0100] As shown in Table 2, the wastewater treatment process of this invention can effectively degrade high-molecular-weight organic pollutants, enabling the water quality to meet the Class A discharge standard. The results demonstrate that the device described in this invention, by improving the energy utilization rate of the electron beam irradiation unit, enhances the degradation effect on organic pollutants while treating the same volume of water, significantly improving the overall treatment capacity. Under the same treatment effect, it can increase the treated water volume and reduce treatment costs.

[0101] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for wastewater treatment, characterized in that, The process is carried out in a wastewater treatment apparatus, wherein the wastewater treatment apparatus includes: a container for holding wastewater; a spraying component located on the side wall of the container for spraying the wastewater to be treated into the container in a parabolic manner; an electron beam irradiation component for generating an electron beam, and the electron beam irradiating the parabolic surface of the wastewater to be treated; and a catalyst carrying component for carrying a catalyst; the catalyst carrying component is located in the middle and / or bottom of the container such that the catalyst contacts the parabolic surface and / or contacts the wastewater at the bottom of the container; the electron beam irradiation component includes two or more beam outlets; the electron beam irradiation component emits at least a pair of opposing first and second electron beams, wherein the first electron beam irradiates the bottom surface of the container from top to bottom, and the second electron beam irradiates the top surface of the container from bottom to top, and the beam outlets of the first and second electron beams are respectively located on both sides of the parabolic surface; The method includes: the wastewater to be treated is ejected in a parabolic shape through a spraying component, and after being irradiated by an electron beam emitted by an electron beam irradiation component, it falls into a container; the wastewater to be treated comes into contact with the catalyst on the catalyst support component while being irradiated by the electron beam, and / or the wastewater to be treated comes into contact with the catalyst on the catalyst support component at the bottom of the container; the thickness of the water film on the parabolic surface conforms to h=9×10. -9 E-0.005; where E is the average energy in eV; h is the required water film thickness of the reactor under the wastewater beam in meters; the wastewater flow velocity conforms to v=IE / (2000xelh); where I is the average beam current intensity of the electron beam in A; l is the width of the parabolic water film of the wastewater to be treated in meters; v is the wastewater flow velocity in m / s; x is the absorbed dose required for the wastewater to be treated to meet the discharge standards in Gy; E is the average energy in eV; e is the electron charge.

2. The method according to claim 1, wherein, The length of the water outlet of the spray component is 50cm-200cm, the width is 0.5cm-5cm, and the length-to-width ratio is (25-400):

1.

3. The method according to claim 1, wherein, The electron beam has an energy of 0.5 MeV-10.0 MeV, a beam current intensity of 1 mA-300 mA, and penetrates a water film thickness of 0.5 cm-5 cm.

4. The method according to claim 1, wherein, The energy difference between the first electron beam and the second electron beam is within 50%, and the beam current difference between the first electron beam and the second electron beam is within 50%.

5. The method according to claim 1, wherein, The wastewater contains high-molecular-weight organic compounds.

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