Method and device for removing calcium ions in high-salinity wastewater by using electron beams and application of method and device

Abstract

The invention provides a method and device for removing calcium ions in high-salinity wastewater by using electron beams and application of the method and device, belongs to the field of industrial wastewater, and is characterized in that on the basis of a'carbonate precipitation reaction and high-energy electron beam irradiation 'synergistic process, the phase transformation of calcium carbonate is enhanced through electron beam irradiation, and the settling performance is remarkably improved; the calcium ions in the high-salinity wastewater are efficiently removed, and the removal rate of the calcium ions reaches 95% or above. The method is simple in process and short in treatment period, and the whole process only needs within 1 hour; meanwhile, the precipitate obtained by the process is high in purity, subsequent resource utilization is facilitated, the treatment cost is remarkably reduced, and the technical and economic advantages and environmental friendliness are fully embodied. The device comprises a high-salinity wastewater reactor, an electron beam emitter arranged at the upper part of the high-salinity wastewater reactor and a solid-liquid separation assembly, and is simple in structure, simple and convenient to operate and wide in application range; the device can be used for efficiently removing the calcium ions in the high-salinity wastewater.

Description

Technical Field

[0001] The present invention belongs to the field of industrial wastewater treatment, and in particular relates to a method, a device and an application thereof for removing calcium ions from high-salt wastewater by utilizing electron beams. Background Art

[0002] High-salinity wastewater is widely found in industries such as metallurgy and petrochemicals. Its main characteristic is the presence of multiple, particularly difficult-to-treat cations, such as calcium. High salt concentrations (>50 g / L) and complex ion profiles (including calcium, lithium, magnesium, sodium, and potassium) lead to unpredictable membrane scaling and crystallization processes. The resulting precipitates are often large and prone to scaling, increasing treatment costs.

[0003] Chemical precipitation is commonly used to remove calcium ions from water, but this method has a low removal rate and requires a long treatment time. Alternatively, membrane separation technology can achieve a higher removal rate, but this technology requires frequent membrane replacement, resulting in high investment and operating costs. It also requires strict pretreatment to prevent membrane fouling and is inconvenient to operate. Summary of the Invention

[0004] The main purpose of the present invention is to provide a method, device and application of removing calcium ions from high-salt wastewater using electron beams, aiming to solve the problems of low efficiency and high cost of removing calcium ions from high-salt wastewater using existing technologies.

[0005] To achieve the above object, the present invention provides a method for removing calcium ions from high-salt wastewater using an electron beam, comprising the steps of:

[0006] S1, adjusting the pH value of the high-salt wastewater to be treated to 8-12 to obtain high-salt wastewater; wherein the calcium salt concentration in the high-salt wastewater to be treated is 1-20 g / L; and the total salt concentration in the high-salt wastewater to be treated is greater than 50 g / L.

[0007] S2, adding carbonate to the high-salt wastewater to obtain a mixed solution; the carbonate concentration in the mixed solution is 1.6-45 g / L.

[0008] S3, sequentially subjecting the mixed solution to high-energy electron beam irradiation treatment and solid-liquid separation treatment to obtain a treated solution and coarse mixed crystals of calcium carbonate and calcium oxide; the electron beam current density used in the high-energy electron beam irradiation step is 50-500 μA / cm 2 .

[0009] Furthermore, in step S1, the high-salt wastewater to be treated includes calcium ions and magnesium ions, the calcium ion concentration is 1-20 g / L, and the magnesium ion concentration is 0.2-0.8 g / L; the high-salt wastewater to be treated also includes one or more of the following concentrations of ions: lithium ions with a concentration of 0.05-100 g / L, sodium ions with a concentration of 10-100 g / L, and potassium ions with a concentration of 10-100 g / L.

[0010] Furthermore, in step S3, the high-energy electron beam irradiation treatment is performed for a duration of 1 to 30 minutes.

[0011] Furthermore, in step S3, the acceleration voltage of the electron beam is in the range of 10 to 50 kV.

[0012] Furthermore, in step S2, the molar ratio of magnesium ions, calcium ions and carbonate ions in the mixed solution is 0.1-0.5:1:1-2.

[0013] Furthermore, in step S2, the carbonate includes one or more of sodium carbonate, calcium carbonate and potassium carbonate.

[0014] Furthermore, in step S3, the solid-liquid separation treatment is performed by using an ultrafiltration membrane or nanofiltration membrane with a diameter of 0.01 to 1 μm to perform membrane filtration on the liquid after the high-energy electron beam irradiation treatment.

[0015] Alternatively, the solid-liquid separation treatment is performed by centrifugation filtering the liquid after the high-energy electron beam irradiation treatment at a rotation speed of 3000 to 15000 rpm.

[0016] Furthermore, after step S3, the method further includes: S4, adding the coarse mixed crystals of calcium carbonate and calcium oxide obtained in step S3 to the high-salt wastewater in step S2, and repeating steps S2 and S3 to obtain a decalcified liquid.

[0017] The present invention also provides a device for removing calcium ions in high-salt wastewater using electron beams, comprising a high-salt wastewater reactor, an electron beam emitter arranged on the upper part of the high-salt wastewater reactor, and a solid-liquid separation component.

[0018] The high-salt wastewater reactor comprises an inlet pipe, an outlet pipe and a dosing chamber; the inlet pipe and the outlet pipe are respectively installed on both sides of the side wall of the high-salt wastewater reactor; the dosing chamber is arranged on the top of the high-salt wastewater reactor.

[0019] The high-energy electron beam generated by the electron beam emitter is used for irradiation treatment of the high-salt wastewater in the high-salt wastewater reactor.

[0020] The solid-liquid separation component is communicated with the water outlet pipe and is used for performing solid-liquid separation on the irradiated liquid to obtain treated liquid and coarse mixed crystals of calcium carbonate and calcium oxide.

[0021] The present invention also provides a use of any of the above methods or devices in improving membrane flux.

[0022] The beneficial effects achieved by the present invention are:

[0023] The method provided by the present invention uses an electron beam to remove calcium ions from high-salinity wastewater. Based on a synergistic process of "carbonate precipitation reaction and high-energy electron beam irradiation," electron beam irradiation enhances the phase transformation of calcium carbonate and significantly improves sedimentation performance, achieving efficient calcium ion removal from high-salinity wastewater, with a calcium ion removal rate exceeding 95%. This method is simple and has a short treatment cycle, requiring only less than one hour. Furthermore, the resulting precipitate is highly pure, facilitating subsequent resource utilization and significantly reducing treatment costs, fully demonstrating its technical and economic advantages and environmental friendliness.

[0024] The device provided by the present invention uses electron beams to remove calcium ions in high-salt wastewater, including a high-salt wastewater reactor, an electron beam emitter arranged on the upper part of the high-salt wastewater reactor, and a solid-liquid separation component. The device has a simple structure, easy operation, and a wide range of applications. The device can be used to efficiently remove calcium ions in high-salt wastewater.

[0025] The method or device provided by the present invention for removing calcium ions from high-salt wastewater using electron beams is applied to improving membrane flux, which can solve the problems of "calcium salt scaling and difficult sludge dehydration" in traditional industrial wastewater treatment, reduce treatment costs, improve treatment efficiency, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0027] Figure 1 This is a schematic structural diagram of an apparatus for removing calcium ions from high-salinity wastewater using an electron beam according to an optional embodiment of the present invention;

[0028] Figure 2 This is a scanning electron microscope (SEM) image of the coarse mixed crystals of calcium carbonate and calcium oxide in Example 1 of the present invention;

[0029] Figure 3This is a high-resolution transmission electron microscopy (HRTEM) image of a coarse mixed crystal of calcium carbonate and calcium oxide in Example 1 of the present invention; wherein, Figure 3 (a) HRTEM image before high-energy electron beam irradiation treatment; Figure 3 (b) HRTEM image of a certain area after high-energy electron beam irradiation treatment; Figure 3 (c) HRTEM image of another area after high-energy electron beam irradiation treatment;

[0030] Figure 4 This is a selected area electron diffraction (SAED) pattern of the coarse mixed crystals of calcium carbonate and calcium oxide in Example 1 of the present invention;

[0031] Figure 5 This is a scanning electron microscope (TEM) image of the coarse mixed crystals of calcium carbonate and calcium oxide in Example 2 of the present invention;

[0032] Figure 6 HRTEM images before and after high-energy electron beam irradiation treatment in Example 2 of the present invention; wherein, Figure 6 (a) HRTEM image before high-energy electron beam irradiation treatment; Figure 6 (b) HRTEM image after high-energy electron beam irradiation treatment;

[0033] Figure 7 This is a scanning electron microscope (SEM) image of the coarse mixed crystals of calcium carbonate and calcium oxide in Example 3 of the present invention;

[0034] Figure 8 This is a high-resolution transmission electron microscopy (HRTEM) image of the mixed coarse crystals of calcium carbonate and calcium oxide in Example 3 of the present invention; wherein, Figure 8 (a) is the HRTEM image of a certain area; Figure 8 (b) is the HRTEM image of another area;

[0035] Figure 9 This is a selected area electron diffraction (SAED) pattern of the mixed coarse crystals of calcium carbonate and calcium oxide in Example 3 of the present invention;

[0036] Figure 10 This is a scanning electron microscope (TEM) image of the coarse mixed crystals of calcium carbonate and calcium oxide in Example 3 of the present invention;

[0037] Figure 11 This is a scanning electron microscope (TEM) image of the precipitate in Comparative Example 1 of the present invention;

[0038] Figure 12 This is a comparison diagram of scanning electron microscopy (TEM) and high-resolution projection (HRTEM) images of high-energy electron beam irradiation treatments with different beam densities in Comparative Example 4 of the present invention; wherein, Figure 12 (a) 500 μA / cm 2TEM images of Figure 12 (b) 600 μA / cm 2 TEM images of Figure 12 (c) 500 μA / cm 2 HRTEM images of Figure 12 (d) 500 μA / cm 2 HRTEM image of the time.

[0039] The realization of the objectives, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0041] It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments may be combined with each other. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific embodiments, rather than to limit the scope of protection of the present invention.

[0042] Unless otherwise defined, all technical and scientific terms used in the present invention and those skilled in the art are familiar with the prior art and the present invention. Any method, equipment and material of the prior art similar or equivalent to the methods, equipment and materials described in the embodiments of the present invention can also be used to realize the present invention. When the embodiments provide numerical ranges, it should be understood that, unless otherwise specified in the present invention, the two endpoints of each numerical range and any numerical value between the two endpoints can be selected. The test methods for the following examples without specifying specific conditions are usually based on conventional conditions or according to the conditions recommended by each manufacturer. The materials or reagents required in the following examples are commercially available unless otherwise specified.

[0043] In order to solve the problems of low efficiency and high cost of removing calcium ions from high-salt wastewater using existing technologies, the present invention provides a method for removing calcium ions from high-salt wastewater using an electron beam, comprising the steps of:

[0044] S1, adjust the pH value of the high-salt wastewater to be treated to 8-12 to obtain high-salt wastewater; wherein, the calcium salt concentration in the high-salt wastewater to be treated is 1-20g / L; the total salt concentration in the high-salt wastewater to be treated is>50g / L. Specifically, adjusting the pH value of the high-salt wastewater to be treated to 8-12 can effectively reduce the solubility of calcium salts, accelerate the transformation of calcium salts into intermediate phases such as amorphous calcium carbonate (ACC), promote the initial formation of calcium carbonate crystal nuclei and improve the stability of crystal nuclei, thereby providing good initial conditions for subsequent electron beam enhanced crystal nucleus sedimentation. Preferably, the pH value of the high-salt wastewater to be treated is adjusted to 11 or 12; the amorphous calcium carbonate crystal nuclei formed at this time are more abundant, which is conducive to subsequent electron beam irradiation enhanced crystallization.

[0045] It should be emphasized that the calcium salt concentration in the high-salt wastewater treated by the present invention is ≥10g / L and the total salt concentration is >50g / L. In this high-salt, high-calcium environment, the traditional chemical precipitation method (only by adding carbonate) has extremely limited effect on the removal of calcium ions. Experiments have found that when only chemical precipitation is used, the calcium ion removal rate is usually less than 70%, which is difficult to meet the actual needs of high-salt wastewater treatment.

[0046] S2, adding carbonate to the high-salinity wastewater to obtain a mixed solution; the carbonate concentration in the mixed solution is 1.6 to 45 g / L. Specifically, when the carbonate concentration in the mixed solution is 1.6 to 45 g / L, uniform formation of amorphous calcium carbonate (ACC) crystal nuclei can be promoted in a high-salinity environment and excessive agglomeration of the crystal nuclei can be suppressed.

[0047] S3, sequentially subjecting the mixed liquid to high-energy electron beam irradiation treatment and solid-liquid separation treatment to obtain a treated liquid and coarse mixed crystals of calcium carbonate and calcium oxide; the electron beam current density used in the high-energy electron beam irradiation treatment step is 50 to 500 μA / cm 2 Specifically, the beam current density is 50 to 500 μA / cm 2 According to the following mechanism found during the experiment:

[0048] Energy deposition and crystal orientation: at 50μA / cm 2 When the beam density is increased to 500 μA / cm, the energy deposition per unit volume can only trigger the transformation of part of ACC into stable crystal forms such as calcite / aragonite, and the increase of the number density of crystal nuclei and the sedimentation rate is limited. 2 , which can increase the instantaneous temperature of the ACC surface to 100-500℃ and the local pressure pulse to 0.1-0.5MPa, accelerate ion diffusion and rearrangement, and directionally generate coarse calcite crystals with an average grain size of 2-5μm;

[0049] Anti-agglomeration and resource utilization: The mechanical oscillation effect generated under moderate beam intensity effectively inhibits excessive agglomeration of crystal nuclei, improves the dispersion of sediment, and is conducive to subsequent washing and resource utilization;

[0050] Out-of-range risk: If the beam current density is less than 50μA / cm 2 , insufficient energy deposition, inadequate ACC conversion, and calcium ion removal efficiency reduced to <80%; if the beam current density is >500μA / cm 2 Local overheating will cause grain melting or agglomeration, and the calcium oxide ratio will increase significantly (>20%), which will not only reduce the sedimentation efficiency but also be detrimental to subsequent resource recovery.

[0051] For the high-salt wastewater of the present invention (calcium salt concentration is 1-20g / L, total salt concentration>50g / L), the beam density is set to 50-500μA / cm 2 , achieving directional and efficient calcium carbonate crystal formation and calcium ion removal, breaking through the technical bottleneck of low treatment efficiency and poor crystal nucleus control of traditional chemical precipitation under high salt conditions.

[0052] In an optional embodiment, the pH of the high-salinity wastewater is first adjusted to 11 or 12 according to step S1 to form pretreated high-salinity wastewater; then carbonate is added according to step S2 to make the carbonate concentration 12-18 g / L to generate uniformly dispersed ACC; then, the ACC is detected at 50-500 μA / cm 2 The mixed liquid is irradiated with a high-energy electron beam with a beam current density to directionally catalyze and generate calcite / calcium oxide mixed coarse crystals; finally, the treated liquid and mixed coarse crystals are recovered separately through solid-liquid separation.

[0053] When a high-energy electron beam is incident on an ACC sample, the electrons undergo elastic and inelastic collisions with ions and molecules in the sample, resulting in drastic changes in local instantaneous temperature and pressure. The energy deposition and thermo-pressure effects can be described by the following formula:

[0054] ΔT=jUte / ρV s c p , ΔP=KΔT (1)

[0055] Where j is the beam current density (A / cm 2 ), U is the accelerating voltage (V), t is the irradiation time (s), e = 1.60 × 10 -19 , C is the electron charge, ρ is the ACC density (g / cm 3 ), V s is the sample volume (cm 3 ), c p is the specific heat capacity (J / g·K), and K is the bulk modulus of the material (Pa).

[0056] At an accelerating voltage of 30 kV and a beam current density of 50 to 500 μA / cm 2Under these conditions, the high-energy electron beam precisely deposits energy into amorphous calcium carbonate (ACC) at the nanometer-microsecond scale, causing local breakage and recombination of the ACC molecular chains, greatly increasing the crystal nucleus density and accelerating the crystal growth rate.

[0057] The method provided by the present invention uses an electron beam to remove calcium ions from high-salinity wastewater. Based on a synergistic process of "carbonate precipitation reaction and high-energy electron beam irradiation," electron beam irradiation enhances the phase transformation of calcium carbonate and significantly improves sedimentation performance, achieving efficient calcium ion removal from high-salinity wastewater, with a calcium ion removal rate exceeding 95%. This method is simple and has a short treatment cycle, requiring only less than one hour. Furthermore, the resulting precipitate is highly pure, facilitating subsequent resource utilization and significantly reducing treatment costs, fully demonstrating its technical and economic advantages and environmental friendliness.

[0058] Furthermore, in step S1, the high-salt wastewater to be treated includes calcium ions and magnesium ions, with a calcium ion concentration of 1 to 20 g / L and a magnesium ion concentration of 0.2 to 0.8 g / L; the high-salt wastewater to be treated also includes one or more of the following ions: lithium ions with a concentration of 0.05 to 100 g / L, sodium ions with a concentration of 10 to 100 g / L, and potassium ions with a concentration of 10 to 100 g / L. Specifically, the high-salt wastewater to be treated with this ion distribution can be derived from typical steel smelting machine head ash washing water, and the overall ionic strength can reach 3 to 10 mol / L, which is a typical industrial high-salt and high-hardness working condition. In such a high-intensity environment with the coexistence of multiple valence ions, the traditional chemical precipitation method is prone to bottlenecks such as sparse crystal nuclei, slow sedimentation, and poor crystal phase controllability.

[0059] The present invention innovatively designs an electron beam enhanced crystallization process based on the above ion spectrum characteristics. The high salt system has a special ion synergistic inhibition effect: Li + With Mg 2+ In high salt systems, Li has a significant effect on the initial morphology of calcium carbonate. + With Mg 2+ At a certain concentration, they will stabilize the amorphous state of calcium carbonate and inhibit its growth into a stable large-grained calcite state. + In wastewater solutions above 50 mg / L, there will be a phenomenon of inhibition of calcium carbonate crystallization. 2+ When the calcium ion ratio is above 1 / 10, the amorphous state of stable calcium carbonate will also exist, and there is a process that promotes the transformation of calcium carbonate into aragonite phase. Therefore, combined with the precise beam current density (50~500μA / cm 2 ), stimulate the crystal transformation process of ACC and the molecular structure of calcium carbonate, and achieve increased crystallinity and phase transformation.

[0060] Furthermore, in step S3, the high-energy electron beam irradiation treatment lasts for 1 to 30 minutes. Specifically, when the irradiation time is 5 to 15 minutes, the conversion rate of ACC to calcite / aragonite crystals can reach over 90%, and the calcium ion removal rate can be stabilized at over 98.5%. If the irradiation time is less than 1 minute, insufficient energy deposition and inadequate ACC conversion occur, and the calcium ion removal rate drops to less than 80%. If the irradiation time exceeds 30 minutes, not only does it increase energy consumption, but it can also damage some crystals.

[0061] Furthermore, in step S3, the acceleration voltage of the electron beam is in the range of 10 to 50 kV. Specifically, the lower voltage (10 to 20 kV) is mainly used to activate the surface ACC nuclei, and the nucleation rate is moderate; the medium voltage (20 to 35 kV) achieves the overall deep excitation of ACC, and the directional growth efficiency of calcite crystal is the highest;

[0062] High-frequency voltage (35-50 kV) can further increase local temperature and pressure, but exceeding 50 kV can easily cause grain melting and excessively high calcium oxide ratio (>20%), which is not conducive to sedimentation and resource recovery.

[0063] The energy transfer of the electron beam can be described by the following equation:

[0064]

[0065] Where j is the beam current density (A / cm 2 ), U is the acceleration voltage (V), A is the scanning coverage area (cm 2 ), t is the irradiation time (s).

[0066] Furthermore, in step S2, the molar ratio of magnesium ions, calcium ions, and carbonate ions in the mixed solution is 0.1-0.5:1:1-2. Specifically, during the experiment, it was found that based on the following points, the molar ratio of magnesium ions, calcium ions, and carbonate ions in the mixed solution needs to be adjusted to meet the ratio of 0.1-0.5:1:1-2:

[0067] Nucleation control: Mg 2+ It exists in a moderate amount of 0.1 to 0.5, which can partially replace Ca 2+ The coordination sites in the amorphous calcium carbonate (ACC) precursor inhibit ACC agglomeration and improve the dispersion of the crystal nuclei, thereby providing a more uniform precursor structure for subsequent electron beam irradiation.

[0068] Crystal phase selection: CO3 2- Excess (1-2) can ensure sufficient precipitation of Ca 2+ Generate ACC while avoiding excess CO3 2- Leading to large particle precipitation and secondary agglomeration; when CO3 2- / Ca2+ When the value is greater than 2, loose aragonite phase is easily generated, while when it is less than 1, the crystal nuclei are insufficient, both of which are not conducive to the subsequent irradiation directional growth.

[0069] Kinetic equilibrium: This molar ratio range can be + >50g / L) environment, to achieve Mg 2+ The moderate passivation of the crystallization rate achieves an optimal balance between the rate and size of ACC nuclei, providing an ideal initial structure for the electron beam-induced chain scission-recombination process. The specific ratio of magnesium ions, calcium ions, and carbonate ions in the mixed solution inhibits unfavorable agglomeration while ensuring the number and activity of nuclei, providing a uniform, high-density amorphous precursor structure for the directional induction of calcite crystals during electron beam irradiation.

[0070] When Mg 2+ :Ca 2+ :CO3 2- When the ratio is 0.4:1:1.3, the ACC crystal nucleus density is the highest and the calcium ion removal rate reaches 99.0%; if the carbonate ion is excessive (>1.5mol / mol), large particle precipitation is easily formed and the crystal nucleus dispersion decreases; if the carbonate ion is insufficient (<1.2mol / mol), the number of crystal nuclei is insufficient and the removal efficiency is reduced.

[0071] Furthermore, in step S2, the carbonate comprises one or more of sodium carbonate, calcium carbonate and potassium carbonate. Preferably, the carbonate is calcium carbonate. In an optional embodiment, a calcium carbonate reagent with a chemical purity of ≥99% is used.

[0072] Furthermore, in step S3, the solid-liquid separation treatment is performed by using a 0.01-1 μm ultrafiltration membrane or nanofiltration membrane to filter the liquid after high-energy electron beam irradiation. Specifically, when using a 0.01-1 μm ultrafiltration membrane or nanofiltration membrane for membrane filtration, the operating pressure is 0.2-0.6 MPa and the membrane flux is 50-150 L / m 2 h, can intercept 2-5μm coarse mixed crystals of calcium carbonate and calcium oxide.

[0073] Alternatively, solid-liquid separation can be performed by centrifuging the high-energy electron beam irradiated liquid at 3,000 to 15,000 rpm. Specifically, centrifugation at 3,000 to 15,000 rpm for 5 to 15 minutes can increase the crystal nucleus recovery rate to >95%, with a turbidity of <5 NTU in the effluent.

[0074] Furthermore, after step S3, the method further comprises: S4, adding the calcium carbonate and calcium oxide mixed coarse crystals obtained in step S3 into the high-salt wastewater of step S2, repeating steps S2 and S3 to obtain a decalcified solution. Specifically, the calcium carbonate / calcium oxide mixed coarse crystals recovered in step S3 are added back into the high-salt wastewater of step S2 at a seed amount of 0.1 to 0.5 g / L, and steps S2 and S3 are repeated to remove the residual calcium carbonate. 2+ The concentration is further reduced to <50mg / L, meeting the standards for discharge or recycled water.

[0075] The present invention also provides a device for removing calcium ions from high-salt wastewater using electron beams, comprising a high-salt wastewater reactor 1, an electron beam emitter 4 arranged on the upper part of the high-salt wastewater reactor, and a solid-liquid separation component 6.

[0076] The high-salt wastewater reactor 1 includes an inlet pipe 2, an outlet pipe 5 and a dosing chamber 3; the inlet pipe 2 and the outlet pipe 5 are respectively installed on both sides of the side wall of the high-salt wastewater reactor 1; the dosing chamber 3 is set on the top of the high-salt wastewater reactor 1.

[0077] The high-energy electron beam generated by the electron beam emitter 4 is used for irradiation treatment of the high-salinity wastewater in the high-salinity wastewater reactor 1 .

[0078] The solid-liquid separation component 6 is connected to the outlet pipe 5 and is used to perform solid-liquid separation on the liquid after irradiation treatment to obtain treated liquid and coarse mixed crystals of calcium carbonate and calcium oxide. Figure 1 In an optional embodiment, the electron beam high-salt wastewater treatment device is composed of the following components connected in sequence and working together: the high-salt wastewater reactor 1 is provided with a water inlet pipe 2 (with an online water inlet module) for receiving raw water; the high-salt wastewater reactor 1 is equipped with a stirring impeller (not shown in the figure) to ensure that the mixed liquid is uniform. The high-salt wastewater reactor 1 is also equipped with a pH / temperature online monitoring module 8 to detect the pH and temperature of the aqueous phase in the high-salt wastewater reactor 1 in real time, and transmit the signal to the control system. The dosing chamber 3 includes a metering pump and a calcium carbonate storage tank, which is used to adjust the pH and Ca 2+ The concentration is automatically added. The circulation pump 9 and the flow distributor will mix the liquid ( Figure 1 The high-salinity wastewater reactor 1 (shown in the shaded area) is continuously circulated in an upper-outlet-lower-inlet manner to the high-salinity wastewater reactor 1 for high-energy electron beam irradiation treatment, which not only improves fluid uniformity but also allows multiple passes through the irradiation area to enhance the treatment effect. The electron beam emitter 4 is installed on the upper part of the high-salinity wastewater reactor 1 and is connected to the high-salinity wastewater reactor 1. Its beam current density can be adjusted within the range of 50 to 500 μA / cm 2, accelerating voltage 10-50kV. The liquid after high-energy electron beam irradiation is drawn out through the outlet pipe 5 and enters the solid-liquid separation component 6, where it is first filtered through a 0.1μm ultrafiltration membrane (operating pressure 0.4MPa) to intercept coarse mixed crystals of calcium carbonate and calcium oxide with a diameter of 2-5μm. 2+ The retained calcium carbonate and calcium oxide mixed coarse crystals are returned to the reactor at a ratio of 0.2 g / L through the reflux pipe through the crystallization product collector 7 and enter the cycle of steps S2 and S3 to further improve the removal efficiency and achieve incremental utilization of seed crystals.

[0079] In another optional embodiment, raw water (high-salt wastewater to be treated) enters the high-salt wastewater reactor 1 from the water inlet pipe 2, and the pH / temperature online monitoring module 8 detects and shows that the pH is 11.5 and the temperature is 30°C; the control system is used to start the dosing chamber 3, and calcium carbonate with a chemical purity of ≥99% is added to make CO3 2- The concentration increased to 1.3 mol / mol (Mg 2+ :Ca 2+ :CO3 2- = 0.4:1:1.3); the circulating pump 9 sends the mixed liquid to the bottom of the electron beam emitter 4, 10kV, 200μA / cm 2 After the irradiation is completed, the liquid treated by the high-energy electron beam irradiation enters the solid-liquid separation component 6 from the outlet pipe 5 for ultrafiltration, and the clear liquid (treated liquid) that meets the standards is discharged, and the crystal product collector 7 recovers the seed crystal (coarse crystals of calcium carbonate and calcium oxide mixture); repeat steps S2 and S3 once, and finally Ca 2+ The removal rate reaches 99.3%, and the seed recovery rate is >94%. Through the integrated process of "online monitoring → precise dosing → electron beam irradiation → controlled separation → seed reflow," this device not only overcomes bottlenecks such as sparse crystal nuclei and difficult crystal phase control in high-salt and high-hardness environments, but also achieves industrial application with high removal rates, low energy consumption, and resource-friendly recycling.

[0080] The device provided by the present invention uses electron beams to remove calcium ions in high-salt wastewater, including a high-salt wastewater reactor, an electron beam emitter arranged on the upper part of the high-salt wastewater reactor, and a solid-liquid separation component. The device has a simple structure, easy operation, and a wide range of applications. The device can be used to efficiently remove calcium ions in high-salt wastewater.

[0081] The present invention also provides an application of any of the above methods or the above devices in improving membrane flux. Specifically, in industrial production and large-scale wastewater treatment systems, common membrane separation processes such as polytetrafluoroethylene (PTFE) filter membranes for plate and frame filter presses, polyvinylidene fluoride (PVDF) ultrafiltration membranes, nanofiltration membranes, reverse osmosis membranes, and ceramic microfiltration membranes are all susceptible to scaling in high-calcium water bodies, resulting in a sharp drop in membrane flux and frequent cleaning. The method and / or device for removing calcium ions from high-salt wastewater provided by the present invention is used for pretreatment, and the Ca ions in the high-salt wastewater to be treated can be removed. 2+ The water content is reduced from ≥10g / L to <50mg / L, and is retained by solid-liquid separation in the form of coarse crystals mixed with calcium carbonate and calcium oxide. The feed water newly fed into the membrane system contains almost no precipitable calcium salt particles.

[0082] Example of PTFE membrane for plate and frame filter press: without pretreatment, influent Ca 2+ ≈10g / L, membrane flux is only 40L / m 2 ·h, after 8 hours of continuous operation, the machine needs to be stopped for cleaning; after the pretreatment of the present invention, the influent Ca 2+ <50mg / L, membrane flux increased to 75L / m 2 ·h, there is no obvious flux attenuation in continuous operation for 24 hours, the cleaning cycle is extended by 3 times, and the cumulative membrane service life is increased by more than 2 times.

[0083] Example of polyvinylidene fluoride (PVDF) ultrafiltration membrane + nanofiltration membrane in series: without pretreatment, Ca 2+ High, calcium scale forms quickly, and the membrane flux in the ultrafiltration stage is 120L / m 2 ·h down to 60L / m 2 h, nanofiltration stage from 80L / m 2 ·h down to 30L / m 2 ·h; After pretreatment of the present invention, the ultrafiltration membrane starts with a flux of 125L / m 2 h, and retention >110 L / m after 24 h 2 h; nanofiltration stage start-up 85L / m 2 h, retention >70 L / m after 24 h 2 h, and the overall water reuse rate increased by 15%.

[0084] Reverse osmosis (RO) membrane example: Without pretreatment, the influent calcium hardness is high and the RO membrane flux is 30L / m 2 ·h, chemical cleaning is required after running for 6h; after pretreatment of the present invention, RO influent Ca 2+ <50mg / L, flux increased to 50L / m 2 h, and still maintain >45L / m after 48h of continuous operation 2 ·h, cleaning frequency decreased by 75%.

[0085] The above application scenarios show that the method and / or device for removing calcium ions from high-salt wastewater by electron beam provided by the present invention can not only effectively inhibit the formation of calcium scale in the membrane system, effectively improve the membrane flux and extend the operating cycle, but also reduce the number of membrane cleaning times and maintenance costs, thereby realizing efficient, economical and environmentally friendly operation of the membrane separation process.

[0086] The method or device provided by the present invention for removing calcium ions from high-salt wastewater using electron beams is applied to improving membrane flux, which can solve the problems of "calcium salt scaling and difficult sludge dehydration" in traditional industrial wastewater treatment, reduce treatment costs, improve treatment efficiency, and has broad application prospects.

[0087] For further understanding of the present invention, now illustrate with examples:

[0088] Example 1

[0089] (1) Water sample source and composition: Laboratory simulated high-salt wastewater to be treated was selected; the ion concentration (g / L) was: Li + 0.05, Mg 2+ 0.20, Na + 10. Ca 2+ 1. K + 10.

[0090] (2) pH adjustment (step S1): raw water is introduced into the high-salt wastewater reactor 1 from the water inlet pipe 2, and NaOH is slowly added through the dosing chamber 3 to adjust the pH value from the original ~7 to 12±0.1 (real-time feedback from the pH / temperature online monitoring module 8) to optimize the generation of ACC precursors.

[0091] (3) Carbonate precipitation (step S2): Na2CO3 with chemical purity ≥99% is added at once through the dosing chamber 3 to make the CO3 in the mixed solution 2- Concentration accuracy up to 1.65g / L, Mg 2+ :Ca 2+ :CO3 2- =0.2:1:1.2), forming a uniformly dispersed ACC precursor mixture.

[0092] (4) High-energy electron beam irradiation and solid-liquid separation (step S3): Irradiation: Start the electron beam emitter 4 with the parameters of acceleration voltage 10 kV and beam current density 50 μA / cm 2 , irradiate for 1 minute.

[0093] (5) Solid-liquid separation: The liquid after high-energy electron beam irradiation is drawn out through the outlet pipe 5 and sent to the centrifuge, and centrifuged at 6000 rpm for 5 minutes to obtain the treated liquid and the retained calcium carbonate and calcium oxide mixed coarse crystals (crystals).

[0094] (6) Calcium ion removal effect: Detect the Ca in the liquid after the reaction 2+ 0.1g / L, calculated from the initial 1g / L, the removal rate is 90.0%.

[0095] (7) Crystal morphology and phase structure characterization: SEM ( Figure 2 ):1~2μm calcite crystals can be seen; High-resolution projection image HRTEM ( Figure 3 ;in, Figure 3 (a) HRTEM image before high-energy electron beam irradiation treatment, Figure 3 (b) is the HRTEM image of a certain area after high-energy electron beam irradiation treatment. Figure 3 (c) is the HRTEM image of another area after high-energy electron beam irradiation treatment) phase SAED ( Figure 4 ); XRD analysis of the crystal showed that the main peak was 29.4°(104), indicating that the main crystal phase was calcite.

[0096] (8) Membrane flux effect: The treated liquid was passed through an ultrafiltration membrane (pore size 0.22 μm) and the flux was measured to be 80 L / m 2 ·h.

[0097] Example 2

[0098] (1) Water sample source and composition: The ash washing water from the Anyang Iron and Steel Smelter was selected (measured); ion concentration (g / L): Li + 100, Mg 2+ 0.80, Na + 0, Ca 2+ 8. K + 0.

[0099] (2) pH adjustment (step S1): the same as that in Example 1.

[0100] (3) Carbonate precipitation (S2): Add chemical purity ≥99% Na2CO3 through the dosing chamber 3 at one time to make the CO3 in the mixed solution 2- Concentration accuracy up to 15g / L, Mg 2+ :Ca 2+ :CO3 2- =0.1:1:1.5) to form a uniformly dispersed ACC precursor mixture.

[0101] (4) High-energy electron beam irradiation and solid-liquid separation (step S3): Irradiation: Start the electron beam emitter 4 with the parameters of acceleration voltage 50 kV and beam current density 500 μA / cm 2 , irradiated for 30 minutes; solid-liquid separation was carried out using a 1 μm nanofiltration membrane to obtain treated liquid and coarse mixed crystals of calcium carbonate and calcium oxide.

[0102] (5) Seed crystal circulation (step S4): The retained calcium carbonate and calcium oxide mixed coarse crystals are refluxed to the high-salinity wastewater reactor 1 at a weight ratio of 0.2 g / L, and steps S2 and S3 are repeated.

[0103] (6) Calcium ion removal effect: After secondary treatment, Ca 2+ <0.5mg / L, comprehensive removal rate>99%.

[0104] (7) Crystal characterization: TEM of the coarse mixed crystals of calcium carbonate and calcium oxide ( Figure 5 ): 2-5 μm regular rhombohedral calcite can be seen; XRD detection of the crystal shows that the calcite (104) / (113) double peaks are clear and strong; HRTEM ( Figure 6 ;in, Figure 6 (a) is the mixed solution before high energy electron beam irradiation treatment, Figure 6 (b) is the obtained coarse crystal of mixed calcium carbonate and calcium oxide, where clear lattice fringes can be seen, which change towards a crystalline state with the change of irradiation.

[0105] (8) Membrane flux effect: The treated liquid was passed through an ultrafiltration membrane (pore size 0.22 μm) and the flux was measured to be 120 L / m 2 ·h.

[0106] Example 3

[0107] (1) Water sample source and composition: The simulated water sample of the machine head ash washing water of Anyang Iron and Steel Smelter was selected, and the ion concentration (g / L) was: Li + 1. Mg 2+ 0.50, Na + 10. Ca 2+ 4. K + 10. SO4 2- 10.

[0108] (2) pH adjustment (step S1): raw water is introduced into the high-salt wastewater reactor 1 from the water inlet pipe 2, and NaOH is slowly added through the dosing chamber 3 to adjust the pH value from the original ~7 to 11±0.1 (real-time feedback from the pH / temperature online monitoring module 8) to balance the ACC generation rate and energy consumption.

[0109] (3) Carbonate precipitation (step S2): chemical purity ≥99% Na2CO3, Mg2O3 and Mg2O3 are added in two stages through the dosing chamber 3. 2+ :Ca 2+ :CO3 2- ≈0.3:1:1.3, which can generate uniformly dispersed ACC precursors in a high-salt environment and inhibit premature agglomeration.

[0110] (4) High-energy electron beam irradiation and solid-liquid separation (step S3): Irradiation: Start the electron beam emitter 4 with the parameters of acceleration voltage 30 kV and beam current density 150 μA / cm 2 , irradiate for 15 minutes.

[0111] (5) Solid-liquid separation: The liquid after high-energy electron beam irradiation is drawn out through the outlet pipe 5, first filtered through a 0.2 μm ultrafiltration membrane (0.4 MPa), and then centrifuged at 6000 rpm for 10 min to obtain the treated liquid and the retained calcium carbonate and calcium oxide mixed coarse crystals (crystals).

[0112] (6) Calcium ion removal effect: Detect the Ca in the liquid after the reaction 2+ 0.2mg / L, calculated from the initial 4g / L, the removal rate is 95%.

[0113] (7) Crystal characterization: SEM ( Figure 7 ): about 3μm uniform rhombohedral calcite crystals with smooth crystal faces can be seen; XRD detection of the crystals shows that the strong peak of calcite (104) is located at 29.4°, and there is no obvious aragonite signal. Figure 8 As shown (wherein, Figure 8 (a) is the HRTEM test result of a certain area, Figure 8 (b) is the HRTEM test result of another area); select electron diffraction SAED ( Figure 9 );TEM image of the crystal is as follows Figure 10 shown.

[0114] (8) Membrane flux effect: The treated liquid was passed through an ultrafiltration membrane (pore size 0.22 μm) and the flux was measured to be 100 L / m 2 ·h.

[0115] Comparative Example 1

[0116] Compared with Example 1, only the high-energy electron beam irradiation operation is not performed. That is, Na2CO3 with a chemical purity of ≥99% is added at once through the dosing chamber 3 to make the CO3 in the mixed solution 2- Concentration accuracy up to 1.65g / L, Mg 2+ :Ca 2+ :CO3 2- =0.2:1:1.2) to form a uniformly dispersed ACC precursor mixture. Precipitation and separation: After standing for 30 minutes, centrifuge at 3000 rpm for 5 minutes to separate the supernatant and the precipitate.

[0117] Results: Detection of Ca in supernatant 2+ 0.2g / L, calculated from the initial 1g / L, the removal rate is 80.0%. The TEM of the precipitation is mostly irregular ACC precursor ( Figure 11); the flux of ultrafiltration membrane (pore size 0.22μm) was only 45L / m 2 ·h.

[0118] Comparative Example 2

[0119] Compared with Example 1, the Ca 2+ The concentration is 0.5g / L and high energy electron beam irradiation is not performed. That is, chemical purity ≥99% Na2CO3 is added at once through the dosing chamber 3 to make the CO3 in the mixed solution 2- Concentration accuracy up to 1.65g / L, Mg 2+ :Ca 2+ :CO3 2- =0.2:1:1.2) to form a uniformly dispersed ACC precursor mixture. Precipitation and separation: After standing for 30 minutes, centrifuge at 6000 rpm for 5 minutes to separate the supernatant and precipitate.

[0120] Results: Detection of Ca in supernatant 2+ 0.03g / L, calculated from the initial 0.5g / L, the removal rate is 94%. The SEM of the precipitate is mainly smooth calcite; the flux measured by ultrafiltration membrane (pore size 0.22μm) is 80L / m 2 ·h.

[0121] Low calcium concentration (Ca 2+ <1g / L), a certain membrane flux and calcium removal effect can still be achieved under certain conditions, so there is no need to adopt this method at this time.

[0122] Comparative Example 3

[0123] Compared with Example 3, only the beam current density is adjusted. That is, the electron beam emitter 4 is started with the parameters of acceleration voltage 10 kV and beam current density 20 μA / cm 2 , irradiate for 15 min. Finally, the supernatant and precipitate are separated.

[0124] Results: Detection of Ca in supernatant 2+ 0.95g / L, calculated from the initial 4g / L, the removal rate is about 75.0%. The TEM of the precipitate mainly shows incompletely converted ACC and irregular microcrystals. No obvious changes in the crystals were observed after irradiation. The flux of the ultrafiltration membrane (pore size 0.22μm) was measured to be 60L / m 2 ·h.

[0125] When the beam current density drops to 20 μA / cm 2 When the electron energy is insufficient, the electron energy deposition results in insufficient ACC conversion, a significant decrease in calcium removal rate, and significantly poor membrane anti-scaling effect, which verifies the key role of the lower limit of beam density on process performance.

[0126] Comparative Example 4

[0127] Compared with Example 3, only the beam current density is adjusted. That is, the electron beam emitter 4 is started with the parameters of acceleration voltage 30kV and beam current density 600μA / cm 2 , irradiate for 30 min. Finally, the supernatant and precipitate are separated.

[0128] Results: Detection of Ca in supernatant 2+ 0.76g / L, calculated from the initial 4g / L, the removal rate is about 80%.

[0129] When the beam current density is 500 μA / cm 2 TEM and HRTEM detection were performed when the beam current density was 600 μA / cm 2 TEM and HRTEM tests were also performed; the test comparison results are as follows Figure 12 As shown (wherein, Figure 12 (a) 500 μA / cm 2 TEM test results at Figure 12 (b) 600 μA / cm 2 TEM test results at Figure 12 (c) 500 μA / cm 2 HRTEM test results at Figure 12 (d) 500 μA / cm 2 HRTEM test results at ). Figure 12 It can be seen that the TEM of the precipitate mostly shows incompletely converted ACC and irregular microcrystals. HRTEM observed that the crystals were broken by the electron beam after irradiation, resulting in a partially amorphous state. The ultrafiltration membrane (pore size 0.22μm) measured a flux of 58L / m 2 ·h.

[0130] In summary, the above technical solutions of the present invention are only preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention's description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for removing calcium ions from high-salt wastewater using an electron beam, characterized in that: Including steps: S1, adjusting the pH value of the high-salt wastewater to be treated to 8-12 to obtain high-salt wastewater; Wherein, the calcium salt concentration in the high-salt wastewater to be treated is 1-20 g / L; the total salt concentration in the high-salt wastewater to be treated is >50 g / L; S2, adding carbonate to the high-salt wastewater to obtain a mixed solution; the carbonate concentration in the mixed solution is 1.6 to 45 g / L; S3, sequentially subjecting the mixed solution to high-energy electron beam irradiation treatment and solid-liquid separation treatment to obtain a treated solution and coarse mixed crystals of calcium carbonate and calcium oxide; the electron beam current density used in the high-energy electron beam irradiation step is 50-500 μA / cm 2 .

2. The method for removing calcium ions from high-salt wastewater using an electron beam according to claim 1, wherein: In step S1, the high-salt wastewater to be treated includes calcium ions and magnesium ions, the calcium ion concentration is 1-20 g / L, and the magnesium ion concentration is 0.2-0.8 g / L; the high-salt wastewater to be treated also includes one or more of the following concentrations of ions: lithium ions with a concentration of 0.05-100 g / L, sodium ions with a concentration of 10-100 g / L, and potassium ions with a concentration of 10-100 g / L.

3. The method for removing calcium ions from high-salt wastewater using an electron beam according to claim 1, wherein: In step S3, the high-energy electron beam irradiation treatment is performed for a duration of 1 to 30 minutes.

4. The method for removing calcium ions from high-salt wastewater using an electron beam according to claim 1, wherein: In step S3, the acceleration voltage of the electron beam is in the range of 10 to 50 kV.

5. The method for removing calcium ions from high-salt wastewater using electron beams according to claim 1, wherein: In step S2, the molar ratio of magnesium ions, calcium ions and carbonate ions in the mixed solution is 0.1-0.5:1:1-2.

6. The method for removing calcium ions from high-salt wastewater using electron beams according to claim 1, wherein: In step S2, the carbonate includes one or more of sodium carbonate, calcium carbonate and potassium carbonate.

7. The method for removing calcium ions from high-salt wastewater using electron beams according to claim 1, characterized in that: In step S3, the solid-liquid separation treatment is performed by using a 0.01-1 μm ultrafiltration membrane or nanofiltration membrane to perform membrane filtration on the liquid after the high-energy electron beam irradiation treatment; Alternatively, the solid-liquid separation treatment is performed by centrifugation filtering the liquid after the high-energy electron beam irradiation treatment at a rotation speed of 3000 to 15000 rpm.

8. The method for removing calcium ions from high-salt wastewater using electron beams according to claim 1, wherein: After step S3, the method further includes: S4, adding the coarse mixed crystals of calcium carbonate and calcium oxide obtained in step S3 into the high-salt wastewater in step S2, and repeating steps S2 and S3 to obtain a decalcified liquid.

9. A device for removing calcium ions from high-salt wastewater using electron beams, characterized in that: It comprises a high-salt wastewater reactor, an electron beam emitter arranged on the upper part of the high-salt wastewater reactor, and a solid-liquid separation component; The high-salt wastewater reactor comprises an inlet pipe, an outlet pipe and a dosing chamber; the inlet pipe and the outlet pipe are respectively installed on both sides of the side wall of the high-salt wastewater reactor; the dosing chamber is set on the top of the high-salt wastewater reactor; The high-energy electron beam generated by the electron beam emitter is used for irradiating the high-salt wastewater in the high-salt wastewater reactor; The solid-liquid separation component is communicated with the water outlet pipe and is used for performing solid-liquid separation on the irradiated liquid to obtain treated liquid and coarse mixed crystals of calcium carbonate and calcium oxide.

10. Use of the method according to any one of claims 1 to 8 or the device according to claim 9 in improving membrane flux.

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