Preparation and Application of a High-Efficiency Particle Electrode for Three-Dimensional Electrolysis Process of Wastewater

Abstract

The present invention belongs to the technical field of material chemistry particles, and discloses the preparation and application of a high-efficiency particle electrode applied to the three-dimensional electrolysis process of wastewater. The particle electrode of the present invention is prepared from iron powder, copper powder, titanium dioxide, γ-Al2O3, a catalytic substance and activated carbon powder through pressing and sintering. The prepared particle electrode has high efficiency, stable performance, small electrode loss, low power consumption, extremely small amount of sludge generated during electrolysis, and will not show surface passivation or caking after long-term use. The particle electrode can be used as a filler to prepare an electrolysis reactor and can be used to treat organic pollutant wastewater.

Description

Technical Field

[0001] The present invention relates to the technical field of material chemical particles, and specifically relates to the preparation and application of a high-efficiency particle electrode used in the three-dimensional electrolysis process of wastewater. Background Art

[0002] Currently, the particle electrodes that have achieved engineering applications in the three-dimensional electrolysis process of wastewater are mainly activated carbon particles and iron-carbon particles. Other new particle electrodes mainly remain in the research stage, and these new particle electrodes can be divided into three types. The first type is the supported particle electrode prepared by the sol-gel method. For example, Sun Yongjun et al. from Nanjing Tech University prepared Ti / Sn / γ-Al 2 O 3 particle electrodes by the sol-gel method, and Zhang Fang from Tongji University prepared Mn-Sn-Sb / γ-Al 2 O 3 particle electrodes, etc. The second type is the supported particle electrode prepared by the impregnation roasting method. For example, Liu Wei from Qilu University of Technology prepared particle electrodes such as Fe / coke powder, Cu / coke powder, Ni / coke powder, etc., and Song Dihui from Harbin Institute of Technology prepared Fe / Fe 2 O 3 / Fe 3 O 4 / activated carbon particle electrodes. The third type is prepared by the roasting method. For example, Li Ming from Hunan Normal University prepared CuO-ZnO / porous ceramic particle electrodes by high-temperature roasting, etc.

[0003] Among the above new particle electrodes, although activated carbon particles and iron-carbon particles as particle electrodes have achieved engineering applications in the three-dimensional electrolysis of wastewater, there are some significant application defects. The impedance of activated carbon particles is small, and it is easy to form a short-circuit current in the three-dimensional electrolysis reactor, reducing the current efficiency, thereby resulting in poor degradation efficiency of pollutants in the wastewater. In addition, activated carbon particles are also prone to breakage and pulverization, and the pulverized particles will be carried away by the water flow, causing high electrode loss. And iron-carbon particles have problems such as easy rust and scaling on the surface, easy agglomeration of particles into lumps, and large amounts of electrolysis sludge generated. Most of the other new particle electrodes are still only in the laboratory research stage. For example, for supported particle electrodes, due to the high price of active components and the need for repeated dissolution, reaction, impregnation, drying, and roasting, the preparation method is too cumbersome and difficult to mass-produce industrially. And the composite porous ceramic particles prepared by high-temperature roasting are mainly composed of inactive substances such as clay or clay, so the electrolysis promotion effect of the particle electrode is limited. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above deficiencies in the background art and provide the preparation and application of a high-efficiency particle electrode used in the three-dimensional electrolysis process of wastewater. The particle electrode of the present invention is made of iron powder, copper powder, titanium dioxide, γ-Al2 O 3 It is prepared from iron powder, copper powder, titanium dioxide, γ - Al 2 O 3 , a catalytic substance and activated carbon powder through pressing and baking. The prepared particle electrode has high efficiency, stable performance, small electrode loss, energy saving, extremely low sludge production during electrolysis, and will not show surface passivation and caking after long - term use. This particle electrode can be used as a filler to prepare an electrolysis reactor and can be used to treat organic pollutant wastewater.

[0005] To achieve the purpose of the present invention, the preparation method of the particle electrode of the present invention includes the following steps:

[0006] (1) Mix iron powder, copper powder, titanium dioxide, γ - Al 2 O 3 , a catalytic substance and activated carbon powder to obtain a mixed material;

[0007] (2) Press and shape the mixed material obtained in step (1), and dry it to obtain a shaped material;

[0008] (3) Bake the shaped material obtained in step (2) to obtain a particle electrode.

[0009] Furthermore, in some embodiments of the present invention, during the mixing process of step (1), it also includes: applying a copper nitrate solution to the raw materials; the mass ratio of the copper nitrate solution to the total mass of the raw materials is 1:12 - 15; the mass concentration of the copper nitrate solution is 5 - 8%.

[0010] In the preparation method of the particle electrode of the present invention, using the copper nitrate solution as the applied solution can, on the one hand, increase the amount of Cu element in the particle electrode; in addition, when copper nitrate decomposes at high temperature, it can generate gaseous substances, which can promote the formation of microporous structures inside the material, increase the specific surface area of the material, and further optimize the material performance.

[0011] Furthermore, in some embodiments of the present invention, the mass ratio of iron powder, copper powder, titanium dioxide, γ - Al 2 O 3 , a catalytic substance and activated carbon powder is 45 - 50:25 - 35:10 - 15:8 - 10:2 - 5:5 - 8.

[0012] Furthermore, in some embodiments of the present invention, the iron powder, copper powder, γ - Al 2 O 3 in step (1) are powder materials with a mesh size of more than 200.

[0013] Furthermore, in some embodiments of the present invention, the catalytic substance in step (1) is a mixture formed by uniformly mixing diamond powder and cobalt powder.

[0014] Preferably, in some embodiments of the present invention, the mass ratio of the diamond powder to the cobalt powder is 50-60:40-50.

[0015] Adding diamond in the preparation method of the particle electrode of the present invention can significantly improve the impedance of the particle electrode, making it easier to generate particle electrodes with independent electrolysis functions. More strongly oxidizing intermediates, free radicals, hydrogen peroxide and other strongly oxidizing substances are generated in the electrolysis system, which can significantly improve the degradation rate of organic pollutants in wastewater. In addition, as a raw material, diamond can endow the prepared particle electrode with strong anti-rust and anti-scaling capabilities, thus effectively reducing the problem of agglomeration between particle electrodes.

[0016] In the present invention, while adding diamond, cobalt is selected as the catalytic substance. On the one hand, the natural catalytic activity of cobalt is utilized to promote the generation of more free radical groups on the surface of the particle electrode; on the other hand, the good wettability of cobalt to diamond is utilized to improve the bonding strength between diamond and other substances in the particle electrode.

[0017] Further, in some embodiments of the present invention, during the pressing and forming process in step (2), the pressure is controlled to be 10-12 kg / cm 2 .

[0018] Further, in some embodiments of the present invention, the drying in step (2) is carried out at a temperature ≤ 20°C, and the drying time is 20-24 h.

[0019] Further, in some embodiments of the present invention, the formed material in step (2) is in the shape of cylindrical or spherical particles.

[0020] Further, in some embodiments of the present invention, the roasting conditions in step (3) are as follows: heating up for 1-1.5 h, after heating the formed material from room temperature to 200°C, continue to heat up for 2-2.5 h, heat up to 550-600°C, keep warm for 2-3 h, then continue to heat up for 3-3.5 h, heat up to 910°C and keep warm for 4 h-6 h.

[0021] In terms of heating up, if the heating rate is too fast, it is easy to cause the material to crack. In terms of the highest firing temperature, if the firing temperature is higher than 910°C or the holding time exceeds 6 h, the materials will melt and agglomerate together and cannot form particulate matter. If the firing temperature is lower than 910°C or the holding time is less than 4 h, the hardness of the product will be reduced.

[0022] On the other hand, the present invention also provides a particle electrode prepared by the aforementioned preparation method. The active ingredient is bimetallic oxides such as iron copper and copper titanium, and it also contains substances with catalytic effects such as cobalt, diamond, and iron carbide. These metal oxides have a high dielectric constant and high impedance. High-impedance particles are prone to depolarization under the action of an electric field, promoting the occurrence of anode and cathode reactions at both ends of the particles, forming a particle electrode with an independent electrolysis effect. In addition, due to the presence of these highly active bimetallic oxides, the anode surface of the particle electrode is prone to generating MO x (·OH) and MO x+1 and other intermediates with strong oxidizing properties. These intermediates can directly oxidize and decompose organic pollutants in wastewater. At the same time, these depolarized particle electrodes can also cause H 2 O and O 2 to lose or gain electrons under the electrolysis effect around them, generating a large amount of ·OH, H 2 O 2 and other substances. These substances have strong oxidizing properties and can efficiently oxidize and decompose organic pollutants.

[0023] On the other hand, the present invention also provides an application of the aforementioned particle electrode. When the particle electrode is used as a filler in an electrolysis reactor, it can significantly improve the electrolytic decomposition ability of the electrolysis reactor for organic pollutants in wastewater. Specifically, the particle electrode filled in the electrolytic cell undergoes depolarization under the action of an external electric field. The depolarized particle electrode is equivalent to countless series-connected micro-electrolysis reactors. Organic pollutants in the wastewater will be directly oxidized and decomposed by strong oxidizing intermediates on the surface of these micro-electrolysis reactors, and will also be indirectly oxidized by a large amount of ·OH, H 2 O 2 and other substances existing around it, thereby significantly improving the removal efficiency of the electrolysis reactor for organic pollutants in wastewater.

[0024] In addition to the above discussion, compared with the prior art, the advantages of the present invention also lie in:

[0025] (1) The particle electrode prepared by the present invention has high impedance, which can reduce the external voltage required for particle depolarization and reduce power consumption.

[0026] (2) The particle electrode prepared by the preparation method of the present invention has the advantages of high efficiency, stable performance, small electrode loss, extremely small amount of electrolysis sludge when used for electrolysis, no surface passivation and caking after long-term use, etc. By filling the particle electrode into the electrolytic cell of the electrolysis reactor, effective degradation of organic pollutants in wastewater can be achieved. It has high use value and good application prospects. At the same time, the preparation method of the present invention has the advantages of simple process and convenient operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 XRD pattern of the particle electrode obtained in Example 1 of the present invention. Detailed implementation mode

[0028] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Additional aspects and advantages of the present invention will be given in part in the following description, will become apparent in part from the following description, or will be understood through the practice of the present invention. It should be understood that the following description is only used to explain the present invention and is not used to limit the present invention.

[0029] As used herein, the terms "comprising", "including", "having", "containing" or any other variation thereof are intended to cover non-exclusive inclusion. For example, a composition, step, method, article or device containing the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article or device.

[0030] The connecting word "consisting of" excludes any unstated element, step or component. If used in a claim, this phrase will render the claim closed, excluding materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the claim body rather than immediately following the subject, it only limits the elements described in that clause; other elements are not excluded from the claim as a whole.

[0031] When an equivalent, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values and lower preferred values, this should be understood to specifically disclose all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, whether or not the ranges are separately disclosed. For example, when the range "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described herein, unless otherwise stated, the range is intended to include its end values and all integers and fractions within the range.

[0032] The singular form includes plural discussion objects, unless clearly indicated otherwise in the context. "Optional" or "any one" means that the matter or event described thereafter may or may not occur, and the description includes the case where the event occurs and the case where the event does not occur.

[0033] Approximate terms in the description and claims are used to modify quantities, indicating that the present invention is not limited to the specific quantity, but also includes the modified parts that are close to the quantity and acceptable without causing changes to the relevant basic functions. Correspondingly, modifying a numerical value with "about", "approximately", etc. means that the present invention is not limited to the exact numerical value. In some examples, the approximate term may correspond to the accuracy of the instrument for measuring the numerical value. In the description and claims of this application, range limitations can be combined and / or interchanged, and if not otherwise stated, these ranges include all sub-ranges contained therein.

[0034] The indefinite articles "a" and "an" before the elements or components of the present invention do not limit the quantity requirement (i.e., the number of occurrences) of the elements or components. Therefore, "a" or "an" should be interpreted as including one or at least one, and the singular form of the element or component also includes the plural form, unless the quantity clearly refers only to the singular form.

[0035] In addition, the descriptions of terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" described below mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms are not necessarily directed to the same embodiment or example. Moreover, the technical features involved in each embodiment of the present invention can be combined with each other as long as they do not conflict with each other.

[0036] The present invention can achieve large-scale industrial production of particle electrodes. The particle electrodes contain iron-copper and copper-titanium bimetallic oxides (such as Figure 1), these metal oxides have high dielectric constants and high impedance. In a three-dimensional electrolytic reaction, the difference between the potential of the particle electrode and the potential of the particle electrode is the driving force for the repolarization of the particle electrode. When the difference reaches a certain value, the particle electrode is repolarized due to electrostatic induction, an anode reaction occurs at one end, and a cathode reaction occurs at the other end, forming a particle electrode with independent electrolytic action. The higher the impedance of the particle, the easier it is to induce under the action of a high-gradient electric field. The high impedance of iron-copper and copper-titanium bimetallic oxides promotes the strong repolarization ability of the particle electrode prepared by the present invention. At the same time, the appropriate addition of diamond with high impedance can further significantly improve the impedance of the particle electrode, making the repolarization ability of the particle electrode of the present invention stronger. In addition, the particle electrode of the present invention is prepared by uniformly mixing the raw materials and then firing, and is non-loaded. There is no problem of the effective components of the particle electrode falling off easily and causing the loss of material properties. At the same time, the use of compression molding and high-temperature firing makes the prepared material hard, overcomes the problem of electrode material breakage, and effectively avoids the problem of broken materials flowing away with the water flow, resulting in excessive material loss and large amount of electrolytic sludge. On the other hand, the addition of diamond powder in proper amount can reduce the surface scaling of materials and the problem of agglomeration between materials. Compared with the existing granular activated carbon particle electrode, the particle electrode prepared by the present invention can improve the COD degradation rate of wastewater by at least 50% under the same electrolysis conditions, and after continuous operation for 40 days, the mass consumption rate of the particle electrode prepared by the present invention does not exceed 0.05%, while the consumption rate of the activated carbon particle electrode is 12.2%.

[0037] Example 1

[0038] A method for preparing a particle electrode comprises the following steps:

[0039] (1) Take 100-mesh diamond powder and cobalt powder respectively, mix them thoroughly in a mass ratio of 50:50 to obtain a mixture A;

[0040] (2) Take iron powder, copper powder, γ-Al 2 O 3 Pass through a 200-mesh sieve, then iron powder, copper powder, titanium dioxide, γ-Al 2 O 3 , mixture A and activated carbon powder are uniformly mixed in a mass ratio of 45:30:10:8:2:5 to obtain mixture B;

[0041] (3) 8% copper nitrate solution and mixed material B are uniformly mixed in a mass ratio of 1:15 to obtain a wet mixed material;

[0042] (4) pressing the wet mixture obtained in step (3) into cylindrical particles with a diameter and height of 0.5 cm at a pressure of 12 kg / cm2, and drying at 18°C ​​for 24 h;

[0043] (5) Place the formed material obtained in step (4) in a corundum crucible for roasting, specifically: heat up for 1.5 h, raise the temperature of the formed material from room temperature to 200 °C, continue to heat up for 2.5 h, raise the temperature to 550 °C, keep it at this temperature for 3 h, continue to heat up for 3.5 h, raise the temperature to 910 °C, keep it at this temperature for 6 h, and then cool naturally for 8 hours, and then take it out of the kiln to obtain the particle electrode.

[0044] In the particle electrode prepared by the above method, the active ingredients are bimetallic oxides such as iron copper and copper titanium.

[0045] Apply the particle electrode prepared in this example as a filler to the electrolytic reactor. Specifically, fill the particle electrode in the electrolytic cell of the electrolytic reactor. The materials of the positive and negative electrode plates of the electrolytic reactor are graphite, and the plate spacing is 5 cm.

[0046] Apply the particle electrode prepared in this example to the treatment of organic pollutant wastewater. Specifically, use the electrolytic reactor filled with the particle electrode in this example to treat the organic pollutant wastewater, including the following steps:

[0047] Pass the organic pollutant wastewater (such as caprolactam production wastewater) into the electrolytic cell of the electrolytic reactor for electrolytic treatment to complete the degradation of the organic pollutants in the wastewater. The specific electrolysis conditions are as follows: the particle electrode fills the space between the positive and negative electrode plates, the wastewater is placed between the positive and negative electrode plates and just submerges the particle electrode filler, the electrolysis time is 60 min, and the electrolysis current intensity is 30 mA / cm 2 .

[0048] Control group: For the Ti / Sn / γ - Al mentioned in the background technology 2 O 3 particle electrode, Fe / Fe 2 O 3 / Fe 3 O 4 / activated carbon particle electrode, CuO - ZnO / porous ceramic, etc., because there are no industrialized finished products, so in the control group, commercially available granular activated carbon particle electrodes are used to replace the particle electrodes of the present invention to treat organic pollutant wastewater, and other conditions are the same. The results are shown in Table 1.

[0049] Table 1 Treatment effect of the electrolytic reactor filled with particle electrodes in Example 1 of the present invention on organic pollutant wastewater

[0050]

[0051]

[0052] The waste water from caprolactam production has a high content of refractory organic substances and high salinity, and is a typical representative of industrial waste water that is difficult to treat. From the data in Table 1, it can be seen that under the same reaction conditions, the electrolytic reactor filled with the particle electrode of the present invention has significantly better removal rates of COD and N-NH 3 than the control group, indicating that the particle electrode has remarkable treatment efficiency for high-concentration and refractory industrial waste water. After 40 days of continuous operation, through weighing and calculation, the mass reduction rate of the particle electrode of the present invention is 0.05%, and the mass reduction rate of the activated carbon particles is 12.2%. The mass reduction mainly comes from the consumption of the particle electrode itself participating in the electrochemical reaction and the loss carried away by the waste water after breakage. The small reduction amount of the particle electrode indicates small electrode loss and less electrolytic sludge production. In addition, in the reports on the treatment of waste water by particle electrodes such as Ti / Sn / γ-Al 2 O 3 , CuO-ZnO / porous ceramics, etc., the waste water is mostly simulated waste water, and the pollutant components in the waste water are single. Comparing these research results, the particle electrode prepared by the present invention has high degradation efficiency for organic pollution in waste water, especially for waste water with complex pollutant components, high COD content and high salinity.

[0053] Example 2

[0054] A preparation method of a particle electrode, comprising the following steps:

[0055] (1) Respectively take diamond powder and cobalt powder with a mesh size of 100, and fully mix them according to a mass ratio of 60:40 to obtain a mixture A;

[0056] (2) Take iron powder, copper powder, and γ-Al 2 O 3 pass through a 200-mesh sieve, and then mix iron powder, copper powder, titanium dioxide, γ-Al 2 O 3 , mixture A, and activated carbon powder evenly according to a mass ratio of 50:25:10:8:2:5 to obtain a mixture B;

[0057] (3) Mix 8% copper nitrate solution and the mixed material B evenly according to a mass ratio of 1:15 to obtain a wet mixture;

[0058] (4) Press the wet mixture obtained in step (3) into cylindrical particles with a diameter and height of 0.5 cm at a pressure of 12 kg / cm², and dry them at 18°C for 24 h;

[0059] (5) Place the formed material obtained in step (4) in a corundum crucible for roasting, specifically: heat up for 1.5 h, raise the temperature of the formed material from room temperature to 200 °C, continue to heat up for 2.5 h, raise the temperature to 550 °C, keep the temperature for 3 h, continue to heat up for 3.5 h, raise the temperature to 910 °C, keep the temperature for 6 h, cool naturally for 8 hours, cool down, and take out of the kiln to obtain particle electrodes;

[0060] In the particle electrodes prepared in the present embodiment above, the active ingredients are bimetallic oxides such as iron copper and copper titanium.

[0061] Apply the particle electrodes prepared in this embodiment as fillers in an electrolytic reactor. Specifically, fill the particle electrodes in the electrolytic cell of the electrolytic reactor. The materials of the positive and negative electrode plates of the electrolytic reactor are graphite, and the plate spacing is 8 cm.

[0062] Apply the particle electrodes prepared in this embodiment to treat organic pollutant wastewater. Specifically, use the electrolytic reactor filled with particle electrodes in this embodiment to treat organic pollutant wastewater, including the following steps:

[0063] Pass the organic pollutant wastewater (such as caprolactam production wastewater) into the electrolytic cell of the electrolytic reactor for electrolytic treatment to complete the degradation of organic pollutants in the wastewater. The specific electrolysis conditions are: the particle electrodes are filled between the positive and negative electrode plates, the wastewater is placed between the positive and negative electrode plates and just submerges the particle electrode fillers, the electrolysis time is 60 min, and the current intensity of electrolysis is 30 mA / cm 2 .

[0064] Control group: For the Fe / coke powder, Cu / coke powder, Ni / coke powder, Fe / Fe 2 O 3 / Fe 3 O 4 / activated carbon and other particle electrodes, because there are no industrialized finished products, so the control group uses commercially available iron-carbon microelectrolysis particle electrodes to replace the particle electrodes of the present invention to treat organic pollutant wastewater, and other conditions are the same. The results are shown in Table 2.

[0065] Table 2 Treatment effect of the electrolytic reactor filled with particle electrodes in Example 2 of the present invention on organic pollutant wastewater

[0066]

[0067] From the comparison table 1-2, it can be seen that the degradation rate of pollutants in the wastewater of caprolactam production by the wastewater electrolysis reactor using iron-carbon particles as particle electrodes is better than that of activated carbon particles, but significantly lower than that of the electrolysis reactor filled with the particle electrodes prepared by the present invention. The biggest problem with iron-carbon particles in the process of electrolysis or micro-electrolysis is that the iron-carbon particles are prone to surface rust and the particles are prone to agglomeration. After 60 days of continuous operation, when the filler was taken out of the reactor, it was found that the iron-carbon particles were agglomerated and the surface scaling was obvious. In contrast, the scaling and agglomeration of the particle electrodes prepared by the present invention were not obvious.

[0068] Example 3

[0069] A method for preparing a particle electrode comprises the following steps:

[0070] (1) Take 100-mesh diamond powder and cobalt powder respectively, mix them thoroughly in a mass ratio of 50:50 to obtain a mixture A;

[0071] (2) Take iron powder, copper powder, γ-Al 2 O 3 Pass through a 200-mesh sieve, then iron powder, copper powder, titanium dioxide, γ-Al 2 O 3 , mixture A and activated carbon powder are uniformly mixed in a mass ratio of 40:30:10:8:5:7 to obtain mixture B;

[0072] (3) 8% copper nitrate solution and mixed material B are uniformly mixed in a mass ratio of 1:12 to obtain a wet mixed material;

[0073] (4) The wet mixture obtained in step (3) was pressed into cylindrical particles with a diameter and height of 0.5 cm at a pressure of 12 kg / cm2, and dried at 18°C ​​for 24 h.

[0074] (5) The molded material obtained in step (4) is placed in a corundum crucible for roasting, specifically: heating the molded material from room temperature to 200°C for 1 hour, continuing to heat it for 2 hours, heating it to 600°C, keeping it warm for 2 hours, continuing to heat it for 3 hours, heating it to 910°C, keeping it warm for 6 hours, naturally cooling it for 8 hours, cooling it, and taking it out of the kiln to obtain a particle electrode.

[0075] In the particle electrode prepared in the above embodiment, the effective components are bimetallic oxides such as iron-copper and copper-titanium.

[0076] The particle electrode prepared in this example is used as a filler in an electrolytic reactor. Specifically, the particle electrode is filled in the electrolytic cell of the electrolytic reactor. The positive and negative plates of the electrolytic reactor are made of graphite, and the distance between the plates is 8 cm.

[0077] The particle electrodes prepared in this example were applied to the treatment of organic pollutant wastewater. Specifically, an electrolytic reactor filled with particle electrodes in an electrolytic cell was used to treat the organic pollutant wastewater, including the following steps:

[0078] The organic pollutant wastewater (such as caprolactam production wastewater) was introduced into the electrolytic cell of the electrolytic reactor for electrolytic treatment to complete the degradation of organic pollutants in the wastewater. The specific electrolysis conditions were as follows: the particle electrodes were filled between the positive and negative plates, the wastewater was placed between the positive and negative plates just to submerge the particle electrode packing, the electrolysis time was 60 min, and the current intensity of electrolysis was 30 mA / cm 2 .

[0079] Control group: One was to replace copper nitrate in the example preparation method with water, and the rest was the same as the example preparation method; the other was to remove the catalyst in the example preparation method, and the added mass of the remaining raw materials was the same as the example preparation method. The particle electrodes prepared by these two control groups were used to treat the organic pollutant wastewater, and other conditions were the same. The results are shown in Table 3.

[0080] Table 3 Treatment effect of the electrolytic reactor filled with particle electrodes on organic pollutant wastewater in Example 3 of the present invention

[0081]

[0082] Comparing the data in Table 3, it can be seen that when the particle electrodes prepared by wetting the materials with water instead of copper nitrate solution, the degradation rate of COD in the wastewater was about 3% lower than the electrolysis efficiency of the particle electrodes prepared in the present invention; when the catalyst was not added, the degradation rate of COD in the wastewater by the prepared particle electrodes was 30 - 35% lower than the electrolysis efficiency of the particle electrodes prepared in the present invention. After 60 days of continuous operation, the particle electrodes prepared without adding the catalyst showed a certain degree of surface scaling. Comparing Tables 1 - 3, it can be seen that the degradation rate of pollutants in the wastewater by the electrolytic reactor filled with the particle electrodes prepared in the present invention remained at a relatively high level and was stable, indicating that the materials prepared by this method could maintain high characteristics and the material properties were stable.

[0083] Example 4

[0084] The mass ratio of diamond powder and cobalt powder in Example 1 was changed, and other conditions remained unchanged. The treatment effect on organic pollutant wastewater is shown in Table 4.

[0085] Table 4 Test results of particle electrodes obtained with different mass ratios of diamond powder and cobalt powder

[0086]

[0087] As can be seen from the above results, in the present invention, diamond powder and cobalt powder are compounded as catalysts, and when the mass ratio of the two is 50-60:40-50, a high removal rate of organic pollutants in wastewater can be maintained. In Example 1, when the mass ratio of diamond in the compound of diamond and cobalt powder is low, the degradation efficiency of the prepared particle electrode for organic pollutants in wastewater decreases significantly. When the mass ratio of diamond is high, the degradation efficiency of the prepared particle electrode for organic pollutants in wastewater can also be maintained at a relatively high level, but the hardness of the particle electrode is lower than that of the particle electrode prepared in Example 1, which is not conducive to stacking and extrusion in the electrolytic cell.

[0088] Those skilled in the art can easily understand that the above description is only for the embodiments of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A preparation method of a particle electrode, characterized in that, the preparation method of the particle electrode comprises the following steps: (1) Mix raw material iron powder, copper powder, titanium dioxide, γ-Al 2 O 3 , a catalytic substance and activated carbon powder to obtain a mixed material; (2) Compress and mold the mixed material obtained in step (1), and dry it to obtain a molded material; (3) Roast the molded material obtained in step (2) to obtain a particle electrode; the catalytic substance in step (1) is a mixture formed by uniformly mixing diamond powder and cobalt powder; in the mixing process of step (1), it further includes: applying a copper nitrate solution to the raw materials; the mass ratio of the copper nitrate solution to the total mass of the raw materials is 1:12 - 15; the mass concentration of the copper nitrate solution is 5 - 8%; In step (1), the mass ratio of iron powder, copper powder, titanium dioxide, γ-Al 2 O 3 , catalytic substance and activated carbon powder is 45-50:25-35:10-15:8-10:2-5:5-8; the mass ratio of the diamond powder to the cobalt powder is 50 - 60:40 - 50.

2. The preparation method of the particle electrode according to claim 1, characterized in that, The iron powder, copper powder, and γ-Al 2 O 3 in step (1) are powder materials with a mesh size of 200 or more.

3. The preparation method of the particle electrode according to claim 1, characterized in that, In the step (2), during the pressing and forming process, the pressure is controlled to be 10-12 kg / cm 2 .

4. The preparation method of the particle electrode according to claim 1, characterized in that, the drying in step (2) is carried out at a temperature ≤ 20°C, and the drying time is 20 - 24 h.

5. The preparation method of the particle electrode according to claim 1, characterized in that, the molded material in step (2) is in the shape of cylindrical or spherical particles.

6. The preparation method of the particle electrode according to claim 1, characterized in that, the roasting conditions in step (3) are: heating for 1 - 1.5 h, after heating the molded material from room temperature to 200°C, continue to heat for 2 - 2.5 h, heat to 550 - 600°C, keep warm for 2 - 3 h, then continue to heat for 3 - 3.5 h, heat to 910°C and keep warm for 4 h - 6 h.

7. A particle electrode, characterized in that, the particle electrode is prepared by using the preparation method described in any one of claims 1 - 6.

8. The application of the particle electrode according to claim 7, characterized in that, the particle electrode is used as a filler in an electrolytic reactor.

9. The application of the particle electrode according to claim 7, characterized in that, the particle electrode is used to treat organic pollutant wastewater.

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