Coating production wastewater treatment system

Abstract

The utility model discloses a treatment system for coating production wastewater, and solves the technical problems of longer process and higher energy consumption of coating production wastewater treatment in the prior art. The treatment system comprises a filter unit, a first filter unit, a second filter unit and a third filter unit which are connected in sequence, wherein the filter unit is used for filtering coating production wastewater and outputting first liquid; the flocculating settling unit is used for performing flocculating settling treatment on the first liquid and outputting second liquid; the flocculating settling unit comprises a first regulating tank and a first settling tank which are connected in sequence, and an agent adding assembly is arranged in the first regulating tank; the softening unit is used for softening the second liquid and outputting electrolyte; the softening unit comprises a second adjusting tank and a second settling tank, and a first alkali liquor adding device is arranged in the second adjusting tank; the electrolytic hydrogen production unit is used for carrying out electrolytic treatment on the electrolyte and outputting third liquid; and the electrolytic hydrogen production unit comprises an electrolytic hydrogen production device.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater purification, and more specifically, to a treatment system for wastewater in paint production. Background Art

[0002] A large amount of wastewater is generated in people's daily life and industrial production. Most of these wastewaters contain pollutants exceeding the standard and need to be treated before discharge. With the development of the hydrogen energy industry, the social demand for hydrogen is gradually increasing, and large-scale and low-cost production of hydrogen is an important prerequisite for the development and utilization of hydrogen energy. If the above-mentioned wastewater can be used to produce hydrogen, it is expected to turn the burden into motivation.

[0003] Among many hydrogen production methods, hydrogen production by electrolyzing wastewater has the advantages of low cost, pollution-free products, and obvious technical advantages. However, there are still the following problems to be solved. The traditional wastewater hydrogen production process first needs to purify and purify the organic matter in the wastewater (usually biochemical reaction and Fenton oxidation reaction), which can reduce the adverse effects of organic matter on the use of electrode materials. However, this will lead to a long water treatment process and high energy consumption.

[0004] In the process of electrolyzing wastewater to produce hydrogen, hydrogen is generally generated at the cathode, and oxygen, chlorine, carbon dioxide, sulfur dioxide and other gases can be generated at the anode according to different electrolytes. An ideal anode material should first have universality and show good electrochemical performance in various electrolytes. For example, it can be used for oxygen evolution or chlorine evolution. Secondly, in order to obtain as high a current density and small overpotential as possible under a certain electric energy, the electrode material needs to have characteristics such as high surface area, high conductivity, good catalytic activity, long-term mechanical and chemical stability, cheapness and safety.

[0005] Generally, noble metals such as Pt, Pd, and Au are considered to be electrode materials with excellent and efficient electrocatalytic performance. However, the electrolysis process in alkaline water bodies involves multi-process water dissociation, and the electrolysis efficiency is far lower than that in acidic water bodies. Even when noble metal electrodes are used, the improvement of the electrolysis efficiency of alkaline water bodies is very limited. Moreover, the sources of noble metals are scarce and the prices are expensive, making large-scale industrial production impossible.

[0006] Therefore, it is necessary to develop a non-noble metal anode material with high activity and stability suitable for electrolyzing alkaline water bodies. Nickel alloys are one of the most intensively studied anode materials due to their simple preparation methods, rich variety of selections, and excellent catalytic performance. However, the current nickel alloy materials have poor universality, high overpotential, poor voltage stability, and poor corrosion resistance, and still cannot be suitable for alkaline water body electrolysis. Summary of the Utility Model

[0007] In a first aspect, the main object of the present utility model is to provide a sintered metal porous material, its preparation method and application, so as to solve the technical problems of poor versatility, high overpotential, poor voltage stability and poor corrosion resistance existing in nickel alloy anode materials in the prior art.

[0008] In order to achieve the object of the above first aspect, the present utility model first provides a sintered metal porous material and its preparation method, and the technical solutions are as follows:

[0009] The sintered metal porous material has three metal layers and the layered structure formed by them. The three metal layers are both composed of Ni element and Hf element, and the ratios of Ni element and Hf element in the three metal layers are different.

[0010] As a further improvement of the above sintered metal porous material: the phases in the XRD pattern of the sintered metal porous material include HfNi 3 intermetallic compound, Hf 3 Ni 7 intermetallic compound, Hf simple substance and Ni simple substance.

[0011] As a further improvement of the above sintered metal porous material: the sintered metal porous material has a first metal layer, a second metal layer wrapping the first metal layer and a third metal layer wrapping the second metal layer, and the Ni element content: the first metal layer > the second metal layer > the third metal layer.

[0012] As a further improvement of the above sintered metal porous material: the first metal layers are multiple and arranged at intervals.

[0013] The preparation method of the sintered metal porous material includes the steps:

[0014] Ball-mill and mix Ni powder and Hf powder to obtain a mixed powder;

[0015] Add a forming aid to the mixed powder, then granulate and screen to obtain formed particles;

[0016] Press the formed particles into shape to obtain a green body;

[0017] Perform a segmented temperature-raising sintering treatment on the green body;

[0018] Perform a segmented temperature-lowering cooling treatment on the green body, and then the sintered metal porous material is obtained.

[0019] As a further improvement to the above method for preparing the sintered metal porous material: the stepwise heating sintering treatment is carried out under a vacuum degree. The heating process is specifically as follows: starting from room temperature, heating to the sintering temperature, during which after heating 50 - 150 °C each time, keeping warm for 40 - 80 min, after heating to the sintering temperature, keeping warm for 150 - 200 min, the sintering temperature is 1250 - 1350 °C, and the heating rate for each heating is 4 - 7 °C / min.

[0020] As a further improvement to the above method for preparing the sintered metal porous material: the process of the stepwise heating sintering treatment is as follows:

[0021] The first stage is heating from room temperature to 400 °C and keeping warm for 60 min;

[0022] The second stage is continuing to heat to 500 °C and keeping warm for 60 min;

[0023] The third stage is continuing to heat to 600 °C and keeping warm for 60 min;

[0024] The fourth stage is continuing to heat to 700 °C and keeping warm for 60 min;

[0025] The fifth stage is continuing to heat to 800 °C and keeping warm for 60 min;

[0026] The sixth stage is continuing to heat to 900 °C and keeping warm for 60 min;

[0027] The seventh stage is continuing to heat to 1000 °C and keeping warm for 60 min;

[0028] The eighth stage is continuing to heat to 1100 °C and keeping warm for 60 min;

[0029] The ninth stage is continuing to heat to 1300 °C and keeping warm for 18 min.

[0030] As a further improvement to the above method for preparing the sintered metal porous material: the stepwise cooling treatment is carried out under a vacuum degree. The cooling process is specifically as follows:

[0031] The first stage is cooling from the sintering temperature to 800 - 9000 °C, and the cooling rate is 10 - 15 °C / min;

[0032] The second stage is continuing to cool to 400 - 500 °C, and the cooling rate is 4 - 7 °C / min;

[0033] The third stage is continuing to cool to below 100 °C, and the cooling rate is 15 - 20 °C / min, then the sintered metal porous material is obtained.

[0034] In order to achieve the above object of the first aspect, the present utility model secondly provides an electrolytic hydrogen production device and an electrolytic hydrogen production method. The technical solutions are as follows:

[0035] An electrolytic hydrogen production device, having an anode, and the anode adopts the sintered metal porous material described in the first aspect above.

[0036] An electrolytic hydrogen production method, using the above electrolytic hydrogen production device to electrolyze an alkaline water body.

[0037] The sintered metal porous material described in the first aspect above, its preparation method and application have the following advantages:

[0038] (1) In the present utility model, Hf (hafnium) is located in Group 3 and is an early transition metal element, and Ni is located in Group 10 and is a late transition metal element. The water splitting activity of perovskite oxides is closely related to the number of d-orbital electrons in transition metal ions, that is, the activity of early transition metal oxides is relatively low, and the activity of late transition metal oxides is relatively high. Through the synergistic effect of early transition metal elements and late transition metal elements, the present utility model effectively reduces the reaction energy barriers of important intermediates (OH*, O*, OOH*), and greatly improves the overall water splitting efficiency.

[0039] (2) The sintered metal porous material of the present utility model contains almost no solid solution alloy, and the metal elements mainly exist in the form of intermetallic compounds. Due to the existence form of the mixed bond of metal bond and covalent bond, it can further optimize the electronic structure of the material. On the one hand, it has significantly better strength and corrosion resistance. On the other hand, it can promote the adsorption and release of ions during the electrolysis process, reduce the dissociation energy barrier of water in the electrolyte system of the electrolyte, improve the electrolysis efficiency, and exhibit good catalytic activity and stability.

[0040] (3) The sintered metal porous material prepared by the element powder reaction synthesis method in the present utility model has micron-sized pores, which can greatly increase the specific surface area of the material and provide sufficient active sites. At the same time, the micron-sized pores provide channels for gas escape, avoiding the enrichment and coverage of catalytic active sites by gas on the electrode surface.

[0041] (4) The sintered metal porous material of the present utility model has a layered structure with different Ni content distributions. Among them, the inner layer has a higher Ni content, which is beneficial to improving the corrosion resistance. The outer layer has a lower Ni content, which can provide sufficient soluble metal ions, and thus helps to balance the stability and reactivity of the anode material. Moreover, the multi-layer structure and the gradient distribution of Ni content are conducive to establishing a potential gradient on the electrode surface, promoting ion transport and electrochemical reactions, and can achieve fine regulation of the electrochemical process and improve the electrolysis efficiency.

[0042] (5) The sintered metal porous material of the utility model has good versatility and can be used for both oxygen evolution reaction and chlorine evolution reaction, and both can be carried out in alkaline electrolyte. It has the advantages of small oxygen evolution overpotential, good voltage stability, good corrosion resistance, etc. It is an anode material that can be widely used.

[0043] (6) The sintering process of the utility model adopts a special heating process. On the one hand, it ensures that the phases formed by sufficient sintering are as much as possible intermetallic compounds, and reduces the content of other impurities such as solid solution alloys, carbon single substance, carbides, and carbon oxides, so that the structure is single, the composition is uniform, and the distribution of various constituent elements is uniform without segregation. On the other hand, it ensures that the material does not deform, shrinks or expands in proportion, and there will be no local melting, bending, etc. On the third hand, it ensures that a large number of pores are generated in the material to increase the specific surface area, thereby improving the reaction efficiency.

[0044] (7) The sintering process of the utility model adopts a special cooling process, which fully considers the phase change and reaction characteristics of Hf-Ni alloy in different temperature ranges. A faster cooling rate is adopted in the high temperature stage, which is conducive to maintaining the basic shape and size stability of the sintered body and avoiding excessive thermal deformation at high temperature; a slower cooling rate is adopted in the medium temperature stage, which can reduce thermal stress, promote the diffusion reaction between Ni and Hf, and optimize the organizational structure; a faster cooling rate is adopted in the low temperature stage, which can not only reduce the long-term heat retention at low temperature, thereby avoiding further thermal deformation and organizational coarsening, but also help to lock the optimized organizational structure that has been formed. Therefore, by adjusting the cooling rate, while maintaining the shape stability of the sintered body, the organizational optimization of the alloy can be promoted, and finally a sintered metal porous material with good performance can be obtained.

[0045] Secondly, the main purpose of the utility model is to provide a water treatment method and a water treatment system to solve the technical problems of long wastewater treatment process and high energy consumption in the prior art.

[0046] In order to achieve the above-mentioned second purpose, the utility model first provides a water treatment method, and the technical solution is as follows:

[0047] Water treatment method, comprising the steps of:

[0048] Pre-treat the wastewater to obtain an electrolyte whose solid content, salt content and pH meet the electrolysis requirements;

[0049] The electrolyte is passed into the electrolytic cell of the electrolytic hydrogen production device for electrolytic treatment to decompose the organic matter and ammonia nitrogen in the electrolyte and produce hydrogen;

[0050] Wherein, the anode of the electrolytic hydrogen production device adopts the sintered metal porous material described in the first aspect above.

[0051] As a further improvement of the above water treatment method:

[0052] Use any combination of air flotation treatment, filtration treatment, and flocculation sedimentation treatment to treat wastewater to obtain an electrolyte solution with a solid content meeting the electrolysis requirements.

[0053] Use any combination of softening treatment, membrane separation treatment, ion exchange treatment, and electrodialysis treatment to treat wastewater to obtain an electrolyte solution with a salt content meeting the electrolysis requirements.

[0054] Use an acidic reagent or a basic reagent to treat wastewater to obtain an electrolyte solution with a pH meeting the electrolysis requirements.

[0055] As a further improvement of the above water treatment method: the solid content of the electrolyte solution ≤ 1 mg / L, the salt content ≤ 15 g / L, and the pH is 12 - 14.

[0056] As a further improvement of the above water treatment method: it also includes performing membrane separation treatment after electrolysis treatment.

[0057] In order to achieve the purpose of the second aspect above, the present utility model secondly provides a water treatment system, and the technical solution is as follows:

[0058] A water treatment system, including:

[0059] A pretreatment unit for pretreating wastewater to obtain an electrolyte solution with a solid content, salt content, and pH meeting the electrolysis requirements.

[0060] An electrolytic hydrogen production unit for electrolyzing the electrolyte solution to decompose organic matter and ammonia nitrogen in the electrolyte solution and generate hydrogen; the electrolytic hydrogen production unit includes an electrolytic hydrogen production device, and the electrolytic hydrogen production device includes an electrolytic cell housing, an anode, and a cathode.

[0061] Wherein, the anode of the electrolytic hydrogen production device uses the sintered metal porous material described in the first aspect above.

[0062] The water treatment method and water treatment system described in the second aspect above have the following advantages:

[0063] First of all, the present utility model directly uses the electrolytic hydrogen production device to electrolyze the electrolyte solution. The acid radical ions in the electrolyte solution lose electrons at the anode and turn into gases, and the gases can be further converted into highly active free radicals such as hydroxyl radical ·OH, sulfur oxygen radical ·SO, and chlorine radical ·Cl, which can deeply oxidize and remove organic matter and ammonia nitrogen. At the same time, water undergoes a reduction reaction at the cathode to generate clean energy hydrogen, which can generate more economic benefits, and using green electricity can fully meet the demand with less electricity cost. Thus, while purifying the water body, the overall economic benefit is significantly improved.

[0064] Secondly, the present utility model can achieve a high electrolysis efficiency by only controlling the solid content, salt content, and pH of the wastewater through pretreatment before electrolysis, without the need for a complex, time-consuming, high-energy-consuming, and large-footprint pretreatment process. The overall water consumption is small, saving chemical agent costs and subsequent treatment costs, and not introducing other metal ions.

[0065] It has been verified that the water treatment method and water treatment system of the present utility model can reduce the concentrations of COD, BOD, and ammonia nitrogen in the electrolyte to meet the discharge standards, and can improve the subsequent valuable resource recovery efficiency and / or impurity removal efficiency.

[0066] In a third aspect, the main purpose of the present utility model is to provide a treatment system for paint production wastewater to solve the technical problems of a long process and high energy consumption in the treatment of paint production wastewater in the prior art.

[0067] The treatment system for paint production wastewater includes, connected in sequence: a filtration unit for filtering the paint production wastewater and outputting a first liquid; a flocculation and sedimentation unit for performing flocculation and sedimentation treatment on the first liquid and outputting a second liquid; the flocculation and sedimentation unit includes a first adjustment tank and a first sedimentation tank connected in sequence, and a chemical agent dosing assembly is provided in the first adjustment tank; a softening unit for softening the second liquid and outputting an electrolyte; the softening unit includes a second adjustment tank and a second sedimentation tank, and a first lye dosing device is provided in the second adjustment tank; an electrolytic hydrogen production unit for electrolyzing the electrolyte and outputting a third liquid; the electrolytic hydrogen production unit includes an electrolytic hydrogen production device.

[0068] As a further improvement of the above treatment system for paint production wastewater: the filtration unit includes a grille and an ultrafiltration device connected in sequence.

[0069] As a further improvement of the above treatment system for paint production wastewater: the flocculation and sedimentation unit further includes a first filter press device.

[0070] As a further improvement of the above treatment system for paint production wastewater: there are two first sedimentation tanks.

[0071] As a further improvement of the above treatment system for paint production wastewater: the chemical agent dosing assembly includes a PAC dosing device, a PAM dosing device, and a demulsifier dosing device.

[0072] As a further improvement of the above treatment system for paint production wastewater: a first pH detection device is further provided in the second adjustment tank.

[0073] As a further improvement of the above treatment system for paint production wastewater: the softening unit further includes a second filter press device.

[0074] As a further improvement to the above-mentioned treatment system for coating production wastewater: it further includes a pH adjustment unit, which includes a third adjustment tank, a second pH detection device, a second lye dosing device, and an acid dosing device. The third adjustment tank is used to store the electrolyte solution and output the electrolyte solution to the electrolytic hydrogen production unit.

[0075] As a further improvement to the above-mentioned treatment system for coating production wastewater: it further includes a reverse osmosis membrane device for membrane separation treatment of the third liquid.

[0076] The treatment system for coating production wastewater described in the above third aspect has the following advantages:

[0077] The traditional treatment system for coating production wastewater adopts a treatment method of first Fenton oxidation treatment and then biochemical treatment (hydrolysis acidification + UBF + two-stage A / O). The load of the biochemical unit is relatively large, and it is difficult to deeply remove pollutants in the water.

[0078] However, the treatment system of the present utility model uses an electrolytic hydrogen production device to replace the complex Fenton oxidation treatment and biochemical treatment. Not only are the input and operation costs significantly reduced, but also organic matter and ammonia nitrogen are effectively removed and hydrogen resources are generated, which is green and environmentally friendly and the economic benefits are significantly improved. Before the electrolytic hydrogen production device, only through the filtration unit, flocculation sedimentation unit, and softening unit can the electrolysis requirements be met, with a small footprint and low input cost. It can be seen that compared with the traditional treatment system, the treatment system of the present utility model has a simple structure, significantly reduced land occupation, energy consumption, and chemical dosage, and significantly improved economic benefits and environmental protection, and has significantly stronger practicability.

[0079] The following further describes the embodiments of the utility model provided in this specification in conjunction with the drawings and specific implementation manners. The additional aspects and advantages of the embodiments of the utility model provided in this specification will be partially given in the following description, partially will become obvious from the following description, or will be understood through the practice of the embodiments of the utility model provided in this specification. Description of the Drawings

[0080] The drawings constituting a part of the embodiments of the utility model provided in this specification are used to assist in understanding the embodiments of the utility model provided in this specification. The content provided in the drawings and the related descriptions in the embodiments of the utility model provided in this specification can be used to explain the embodiments of the utility model provided in this specification, but do not constitute an improper limitation to the embodiments of the utility model provided in this specification.

[0081] Figure 1 SEM photograph of the sintered metal porous material for the embodiment of the present utility model.

[0082] Figure 2Energy dispersive X-ray spectrum of the first metal layer in the SEM photograph of the sintered metal porous material according to the embodiment of the present utility model.

[0083] Figure 3 Energy dispersive X-ray spectrum of the second metal layer in the SEM photograph of the sintered metal porous material according to the embodiment of the present utility model.

[0084] Figure 4 Energy dispersive X-ray spectrum of the third metal layer in the SEM photograph of the sintered metal porous material according to the embodiment of the present utility model.

[0085] Figure 5 Energy dispersive X-ray spectrum of the white spot in the SEM photograph of the sintered metal porous material according to the embodiment of the present utility model.

[0086] Figure 6 X-ray diffraction pattern of the sintered metal porous material according to the embodiment of the present utility model.

[0087] Figure 7 Anodic polarization curve of the sintered metal porous material according to the embodiment of the present utility model.

[0088] Figure 8 Anodic constant current polarization stability curve of the sintered metal porous material according to the embodiment of the present utility model.

[0089] Figure 9 Structural schematic diagram of the treatment system for the paint production wastewater according to the embodiment of the present utility model. Detailed implementation manners

[0090] The following clearly and completely describes the embodiments of the utility model provided in this specification with reference to the accompanying drawings. Those of ordinary skill in the art will be able to implement the embodiments of the utility model provided in this specification based on these descriptions. Before describing the embodiments of the utility model provided in this specification with reference to the accompanying drawings, it should be particularly noted that:

[0091] In the embodiments of the utility model provided in this specification, the technical solutions and technical features provided in each part including the following descriptions can be combined with each other without conflict.

[0092] In addition, the embodiments of the embodiments of the utility model provided in this specification usually only represent a partial embodiment rather than all embodiments of the embodiments of the utility model provided in this specification. Therefore, all other embodiments obtained by those of ordinary skill in the art based on the embodiments of the utility model provided in this specification without creative efforts should fall within the scope of protection of the embodiments of the utility model provided in this specification.

[0093] Regarding the terms and units in the embodiments of the utility model provided in this specification: In the specification, claims and relevant parts of the embodiments of the utility model provided in this specification, the terms "comprising", "including", "having" and any variations thereof are intended to cover non-exclusive inclusion. In addition, other relevant terms and units in the embodiments of the utility model provided in this specification can be reasonably interpreted based on the relevant content of the embodiments of the utility model provided in this specification.

[0094] Figure 1 This is the SEM photograph of the sintered metal porous material of the embodiment of the present utility model.

[0095] As Figure 1 shown, the sintered metal porous material of the present utility model has three metal layers and the layered structure formed by them. The materials within each of the three metal layers are uniform; the three metal layers are all composed of Ni element and Hf element, and the ratios of Ni element and Hf element in the three metal layers are different. The three metal layers are respectively the first metal layer, the second metal layer wrapping the first metal layer, and the third metal layer wrapping the second metal layer, and the first metal layer is multiple and arranged at intervals. The sintered metal porous material also has white spots, and these white spots are discretely distributed in the three metal layers.

[0096] Figure 2 This is the energy-dispersive X-ray spectrum of the first metal layer in the SEM photograph of the sintered metal porous material of the embodiment of the present utility model. Figure 3 This is the energy-dispersive X-ray spectrum of the second metal layer in the SEM photograph of the sintered metal porous material of the embodiment of the present utility model. Figure 4 This is the energy-dispersive X-ray spectrum of the third metal layer in the SEM photograph of the sintered metal porous material of the embodiment of the present utility model. Figure 5 This is the energy-dispersive X-ray spectrum of the white spots in the SEM photograph of the sintered metal porous material of the embodiment of the present utility model. Table 1 shows the atomic concentrations of the first metal layer, the second metal layer, the third metal layer and the white spots.

[0097] Table 1

[0098] Element symbol First metal layer Second metal layer Third metal layer White spot Ni 54.60％ 41.63％ 35.17％ 0 Hf 45.40％ 58.37％ 64.83％ 100％

[0099] As Figure 2-5 shown in and Table 1, the Ni element content: the first metal layer > the second metal layer > the third metal layer, and the white spots are Hf simple substances.

[0100] Figure 6 This is the X-ray diffraction pattern of the sintered metal porous material of the embodiment of the present utility model.

[0101] As Figure 6As shown, the phases in the XRD pattern of the sintered metal porous material include HfNi 3 intermetallic compounds, Hf 3 Ni 7 intermetallic compounds, Hf elemental and Ni elemental. Among them, the content of the elemental phase is very small and there is no solid solution alloy phase.

[0102] The preparation method of the sintered metal porous material according to the embodiment of the present utility model includes the steps:

[0103] (1) Ball-mill and mix Ni powder and Hf powder to obtain a mixed powder; among them, the particle sizes of both Ni powder and Hf powder are 3 - 5 μm, the mass ratio of Ni powder to Hf powder is 44:56, and the ball-milling duration is 12 h.

[0104] (2) Add a forming aid to the mixed powder, then granulate and screen to obtain formed particles; among them, the forming aid is PVB (polyvinyl butyral), the dosage of the forming aid is 4% of the mass of the mixed powder, and the screening uses a 60-mesh sieve.

[0105] (3) Press the formed particles into shape to obtain a green body; among them, under a pressure of 200 MPa, control the pressurization time to be 50 seconds and the pressure holding time to be 70 seconds, that is, press 2 g of formed particles into a rectangular parallelepiped green body with dimensions of 25 * 8 * 2 mm.

[0106] (4) Carry out a segmented heating sintering treatment on the green body;

[0107] (5) Carry out a segmented cooling treatment on the green body, that is, obtain the sintered metal porous material.

[0108] Among them, the segmented heating sintering treatment is carried out under a vacuum degree. The heating process is specifically as follows: start heating from room temperature to the sintering temperature. During this period, after each temperature increase of 50 - 150 °C, keep the temperature for 40 - 80 min. After reaching the sintering temperature, keep the temperature for 150 - 200 min. The sintering temperature is 1250 - 1350 °C, and the heating rate for each temperature increase is 4 - 7 °C / min. Specifically, the process of the segmented heating sintering treatment is as follows:

[0109] The first stage is to heat from room temperature to 400 °C and keep the temperature for 60 min;

[0110] The second stage is to continue heating to 500 °C and keep the temperature for 60 min;

[0111] The third stage is to continue heating to 600 °C and keep the temperature for 60 min;

[0112] The fourth stage is to continue heating to 700 °C and keep the temperature for 60 min;

[0113] The fifth stage is to continue heating to 800 °C and keep the temperature for 60 min;

[0114] The sixth stage is to continue heating up to 900 °C and keep the temperature for 60 min;

[0115] The seventh stage is to continue heating up to 1000 °C and keep the temperature for 60 min;

[0116] The eighth stage is to continue heating up to 1100 °C and keep the temperature for 60 min;

[0117] The ninth stage is to continue heating up to 1300 °C and keep the temperature for 18 min.

[0118] The segmented cooling treatment is carried out under a vacuum degree. The specific cooling process is as follows:

[0119] The first stage is to cool down from the sintering temperature to 800 - 9000 °C at a cooling rate of 10 - 15 °C / min;

[0120] The second stage is to continue cooling down to 400 - 500 °C at a cooling rate of 4 - 7 °C / min;

[0121] The third stage is to continue cooling down to below 100 °C at a cooling rate of 15 - 20 °C / min, thus obtaining the sintered metal porous material.

[0122] An embodiment of the electrolytic hydrogen production device of the present utility model has an anode, and the anode uses the above-mentioned sintered metal porous material.

[0123] An embodiment of the electrolytic hydrogen production method of the present utility model is to electrolyze an alkaline water body by using the above-mentioned electrolytic hydrogen production device.

[0124] In order to verify the electrochemical performance of the sintered metal porous material in the embodiment of the present utility model, an electrochemical workstation is used to test the electrochemical performance of the material, specifically as follows:

[0125] The working electrode of the three-electrode system used is the prepared sintered metal porous material (abbreviated as NiHf electrode), the reference electrode is a mercury / mercuric oxide electrode, the reference electrode is aligned with the center of the working electrode test surface through a Lu capillary (salt bridge) and is separated by 1 - 2 mm, and the auxiliary electrode is a platinum sheet (10 mm × 10 mm × 0.2 mm). The test is carried out in a 1M KOH solution (pH = 14). Before the electrochemical test, the working electrode is sealed. The working area of 0.64 square centimeters is exposed on the surface of the working electrode, and the non-working surface is encapsulated with waterproof raw material tape and 704 silicone rubber, so as to ensure that the current value automatically collected by the computer is the required current density. All electrochemical test data are carried out in a constant temperature water bath. Before the effective data test, the open circuit potential of the working electrode is measured by the three-electrode test method. The open circuit potential of the NiHf electrode is stable at about -0.574V within 30 minutes. After the open circuit potential is stable, the corresponding data test is carried out on the electrode.

[0126] The process of anodic overpotential test is as follows: Select the value of the open-circuit potential that is stable as the first vertex potential, and the value that is 2V higher than the open-circuit potential as the second vertex potential. That is, the polarization test range is 2V, the scanning rate is 4mV / s, and the parameters of the electrolytic cell are selected according to the corresponding reference electrode parameters of mercury / mercuric oxide. Then start the test.

[0127] Figure 7 This is the anodic polarization curve of the sintered metal porous material of the embodiment of the present invention. As Figure 7 shown, the overpotential of the NiHf electrode at 10mA / cm 2 is 313mV, which is close to the data of the commercial Pt / C electrode, indicating that the NiHf electrode of the present invention has excellent anodic oxygen evolution performance in strong alkaline electrolytes.

[0128] The process of anodic constant current polarization stability test is as follows: Select the anodic constant current polarization method for testing, set the constant current density to 100mA / cm 2 , the polarization time is 12h, the potential of the sample is tested for a long time, and the state of the sample is observed at the same time.

[0129] Figure 8 This is the anodic constant current polarization stability curve of the sintered metal porous material of the embodiment of the present invention. As Figure 8 shown, the voltage fluctuation of the NiHf electrode does not exceed 6.84%, indicating that the NiHf electrode of the present invention maintains stable oxygen evolution performance as an anode material in strong alkaline electrolytes.

[0130] The test of corrosion resistance is as follows: It is represented by the open-circuit potential in 1M KOH. The more positive the potential value is, the better the corrosion resistance of the material is. After testing, the corrosion resistance potential of the NiHf electrode is -0.574V, and it has good corrosion resistance.

[0131] The above results show that the sintered metal porous material of the embodiment of the present invention has the advantages of small overpotential, good voltage stability, and good corrosion resistance when used as an anode in strong alkaline solutions, and it is an anode material for electrolytic hydrogen production devices that can be widely used.

[0132] The water treatment method of the embodiment of the present invention includes the steps:

[0133] Treat the wastewater by any several of air flotation treatment, filtration treatment, and flocculation sedimentation treatment to obtain an electrolyte with a solid content meeting the electrolysis requirements; the solid content of the electrolyte ≤ 1mg / L;

[0134] Treat the wastewater by any several of softening treatment, membrane separation treatment, ion exchange treatment, and electrodialysis treatment to obtain an electrolyte with a salt content meeting the electrolysis requirements; the salt content of the electrolyte ≤ 15g / L;

[0135] Treat the wastewater with an acidic reagent or a basic reagent to obtain an electrolytic solution with a pH meeting the electrolysis requirements; the pH of the electrolytic solution is 12 - 14;

[0136] Feed the electrolytic solution into the electrolytic cell of the electrolytic hydrogen production device for electrolytic treatment to decompose the organic matter and ammonia nitrogen in the electrolytic solution and produce hydrogen;

[0137] Perform membrane separation treatment after the electrolytic treatment.

[0138] The water treatment system of the present utility model embodiment includes:

[0139] A pretreatment unit for pretreating the wastewater to obtain an electrolytic solution with a solid content, salt content, and pH meeting the electrolysis requirements;

[0140] An electrolytic hydrogen production unit for electrolytically treating the electrolytic solution to decompose the organic matter and ammonia nitrogen in the electrolytic solution and produce hydrogen; the electrolytic hydrogen production unit includes an electrolytic hydrogen production device, and the electrolytic hydrogen production device includes an electrolytic cell housing, an anode, and a cathode;

[0141] In the above water treatment method and water treatment system, the electrolytic hydrogen production device adopts the electrolytic hydrogen production device for wastewater with the application number 2023117301217 disclosed in the Chinese utility model patent.

[0142] The following are application examples of the water treatment method and water treatment system of the present utility model.

[0143] The wastewater generated by three large paint factories was collected. The wastewater mainly comes from the reaction water in the resin production process and the cleaning water generated during the cleaning of equipment, pipelines, and finished product tanks, etc. The water quality parameters are shown in Table 2 - 4 below.

[0144] As can be seen from Table 2 - 4, the COD of the three paint production wastewaters is relatively high, and some also contain relatively high levels of BOD and ammonia nitrogen, all of which belong to high - concentration organic wastewater.

[0145] Table 2. Wastewater discharge water quality parameter table of a certain paint factory 1

[0146]

[0147] Table 3. Wastewater discharge water quality parameter table of a certain paint factory 2

[0148] Category pH value COD (mg / L) BOD (mg / L) SS (mg / L) Resin and curing agent wastewater 2.5～3.0 200000 40000 ≤500 Architectural coating wastewater 6～7 20000 2000 ＝10000 Comprehensive wastewater 6～9 8000～10000 2000～4000 ≤200

[0149] Table 4. Wastewater discharge water quality parameter table of a certain paint factory 3

[0150]

[0151] Figure 9Schematic structural diagram of the treatment system for coating production wastewater in an embodiment of the present utility model.

[0152] As Figure 9 shown, the treatment system for coating production wastewater includes a filtration unit 100, a flocculation sedimentation unit 200, a softening unit 300, a pH adjustment unit 400, an electrolytic hydrogen production unit 500, and a membrane separation unit 600, which are connected in sequence.

[0153] The filtration unit 100 is used to filter the coating production wastewater and output a first liquid; the filtration unit 100 includes a grille and an ultrafiltration device connected in sequence.

[0154] The flocculation sedimentation unit 200 is used to perform flocculation sedimentation treatment on the first liquid output by the filtration unit 100 and output a second liquid; the flocculation sedimentation unit 200 includes a first adjustment tank, a first sedimentation tank, and a first pressure filtration device connected in sequence; a chemical dosing assembly is provided in the first adjustment tank; there are two first sedimentation tanks, and the supernatant in the second-stage sedimentation tank is the second liquid; the chemical dosing assembly includes a PAC dosing device, a PAM dosing device, and a demulsifier dosing device; the liquid obtained by pressure filtration of the first pressure filtration device is returned to the inlet end of the grille, and the obtained solid residue enters the solid waste treatment unit.

[0155] The softening unit 300 is used to soften the second liquid output by the flocculation sedimentation unit 200 and output an electrolyte; the softening unit 300 includes a second adjustment tank, a second sedimentation tank, and a second pressure filtration device; a first lye dosing device and a first pH detection device are provided in the second adjustment tank; the supernatant in the second sedimentation tank is the electrolyte; the liquid obtained by pressure filtration of the second pressure filtration device is returned to the inlet end of the grille, and the obtained solid residue enters the solid waste treatment unit.

[0156] The pH adjustment unit 400 is used to adjust the pH of the electrolyte output by the softening unit 300; the pH adjustment unit 400 includes a third adjustment tank, a second pH detection device, a second lye dosing device, and an acid dosing device. The third adjustment tank is used to store the electrolyte and output the electrolyte with a pH meeting the requirements to the electrolytic hydrogen production unit 500. When the second pH detection device detects that the pH of the electrolyte does not meet 12 - 14, lye or acid can be added through the second lye dosing device or the acid dosing device for adjustment.

[0157] The electrolytic hydrogen production unit 500 is used to perform electrolysis treatment on the electrolyte output by the pH adjustment unit 400 and output a third liquid.

[0158] The membrane separation unit 600 is used to perform membrane separation treatment on the third liquid output by the electrolytic hydrogen production unit 500. The membrane separation unit 600 includes a reverse osmosis membrane device. Thus, pollutants are further intercepted, and a clear liquid that can be reused is obtained.

[0159] It has been verified that the treatment system for the paint production wastewater can treat the above three types of paint production wastewater, and can make the COD, BOD and ammonia nitrogen meet the Integrated Wastewater Discharge Standard (GB 8978-1996).

[0160] Among the above pollutants:

[0161] SS (Suspended Solids) is suspended solids, referring to the solid substances suspended in water, including inorganic substances, organic substances, sediment, clay, microorganisms, etc. that are insoluble in water, and is one of the indicators for measuring the degree of water pollution.

[0162] COD (Chemical Oxygen Demand) is the chemical oxygen demand, which refers to the amount of reducing substances that need to be oxidized in a water sample measured by chemical methods.

[0163] BOD (Biochemical Oxygen Demand) is the biochemical oxygen demand, which refers to the amount of dissolved oxygen consumed by microorganisms to decompose certain oxidizable substances (especially organic substances) in a certain volume of water within a certain period.

[0164] Ammonia nitrogen refers to the combined nitrogen existing in the form of ammonia or ammonium ions, that is, the nitrogen existing in water in the form of free ammonia (NH 3 ) and ammonium ions (NH 4 + ).

[0165] The above has described the relevant content of the embodiments of the utility model provided in this specification. Those of ordinary skill in the art will be able to implement the embodiments of the utility model provided in this specification based on these descriptions. Based on the above content of the embodiments of the utility model provided in this specification, all other preferred embodiments and examples obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the embodiments of the utility model provided in this specification.

Claims

1. The coating production wastewater treatment system is characterized by: Includes the following connected in sequence: A filtering unit, the filtering unit is used to filter the paint production wastewater and output a first liquid; A flocculation and sedimentation unit, the flocculation and sedimentation unit is used to perform flocculation and sedimentation treatment on the first liquid and output a second liquid; the flocculation and sedimentation unit comprises a first regulating tank and a first sedimentation tank connected in sequence, and a reagent dosing component is provided in the first regulating tank; A softening unit, the softening unit is used to soften the second liquid and output the electrolyte; the softening unit comprises a second regulating tank and a second settling tank, and the second regulating tank is provided with a first alkali solution dosing device; An electrolytic hydrogen production unit, the electrolytic hydrogen production unit is used to electrolyze the electrolyte and output a third liquid; The electrolytic hydrogen production unit includes an electrolytic hydrogen production device.

2. The coating production wastewater treatment system according to claim 1, characterized in that: The filtering unit comprises a grid and an ultrafiltration device which are connected in sequence.

3. The coating production wastewater treatment system according to claim 1, characterized in that: The flocculation and sedimentation unit further comprises a first filter press device.

4. The coating production wastewater treatment system according to claim 1, characterized in that: There are two first sedimentation tanks.

5. The coating production wastewater treatment system according to claim 1, characterized in that: The reagent dosing assembly comprises a PAC dosing device, a PAM dosing device and a demulsifier dosing device.

6. The coating production wastewater treatment system according to claim 1, characterized in that: A first pH detection device is also provided in the second regulating tank.

7. The coating production wastewater treatment system according to claim 1, characterized in that: The softening unit also includes a second filter press device.

8. The coating production wastewater treatment system according to claim 1, characterized in that: It also includes a pH regulating unit, which includes a third regulating tank, a second pH detection device, a second alkali solution adding device and an acid solution adding device. The third regulating tank is used to store electrolyte and output electrolyte to the electrolytic hydrogen production unit.

9. The coating production wastewater treatment system according to claim 1, characterized in that: The invention also includes a reverse osmosis membrane device for performing membrane separation treatment on the third liquid.

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