Electrolytic adsorption device and its application

Abstract

The present application relates to the technical field of chlorine-containing electronic wastewater treatment, and particularly relates to an electrolytic adsorption device and application thereof.The present application provides an electrolytic adsorption device, comprising anodes and cathodes arranged alternately and in parallel; the anode comprises an anode substrate and an anode material coated on the surface of the anode substrate; the anode substrate comprises a titanium foil and a titanium dioxide nanotube layer on the surface of the titanium foil, and the titanium dioxide nanotube layer is a three-dimensional array structure; the anode material is a composite material of SnO2, Sb and RuO2; the cathode comprises a cathode substrate and a cathode material coated on the surface of the cathode substrate, and the cathode material is a mixture comprising a carbon-based material and ferroferric oxide. The electrolytic adsorption device has low cost, does not have strict requirements on the treatment conditions of chlorine-containing electronic wastewater, and can effectively remove COD and / or has a relatively high heavy metal (Cu 2+ ) recovery rate.

Description

Technical Field

[0001] This invention relates to the field of chlorine-containing electronic wastewater treatment technology, and in particular to an electrolytic adsorption device and its application. Background Technology

[0002] Electronic products are becoming increasingly important in people's daily lives. Printed circuit boards (PCBs), as substrates used to assemble electronic components, are the core of electronic products. Their main function is to connect various electronic components through circuits, playing a role in conduction and transmission, and are key electronic interconnects in electronic products.

[0003] The manufacturing process of electronic components is extremely complex, generating wastewater at various stages, including strong acid and alkali wastewater, high-concentration organic wastewater, and wastewater containing heavy metals such as copper, zinc, nickel, and chromium. The water quality is complex and highly variable. Due to the large number and wide distribution of electronics companies, the total discharge volume is enormous, reaching approximately 400 million tons of high-concentration wastewater containing heavy metals annually. Electronic wastewater is characterized by high CODcr concentrations, often reaching 5000–10000 mg / L, and sometimes even as high as 20000 mg / L. Because of its complex composition and high content of recalcitrant organic matter, it is difficult to treat effectively. Therefore, for PCB wastewater treatment, whether the CODcr can meet discharge standards (<100 mg / L) depends primarily on the effectiveness of the wastewater treatment process.

[0004] In terms of water pollutant discharge, heavy metal pollutants emitted by the electronics manufacturing industry, represented by printed circuit boards (PCBs), account for more than 95% of the total. Due to process requirements, wastewater from the PCB and other electronics industries often contains large amounts of chloride ions and heavy metals. The treatment of chlorinated wastewater has long been a challenge in water treatment processes. Heavy metals are highly toxic, difficult to metabolize in the environment, difficult to degrade into harmless substances under natural conditions, and easily bioaccumulated and have biochemical effects. They can enter the human body through the food chain, thus posing a threat to human health. Therefore, electronics wastewater has become one of the most serious pollutants to the environment and one of the most harmful industrial wastewaters to humans.

[0005] Traditional technologies (chemical precipitation, adsorption, biological methods, etc.) treat electronic wastewater, controlling pollutant concentrations to meet discharge standards before discharge. However, the large amount of heavy metals removed is converted into chemical or biological sludge, essentially transforming water pollution into solid waste pollution, failing to truly address the heavy metal hazards. On the other hand, "waste is a resource in the wrong place." These metals in wastewater are often expensive heavy metals. Effective recycling can turn waste into treasure, truly controlling pollution emissions and pollution problems at the source. For example, copper ions in PCB wastewater typically exist in free and complexed states. Electrolytic treatment of copper-containing wastewater can achieve a 90% copper recovery rate, resulting in high economic benefits. Therefore, for electronic wastewater, which is produced in large quantities, recycling the large amounts of heavy metals it contains not only improves economic benefits for enterprises but also maximizes wastewater resource utilization.

[0006] The pressing problems to be solved in the treatment of electronic wastewater pollution include: (1) ensuring the stable operation of wastewater treatment facilities to achieve stable levels of chloride ions, COD, and heavy metal ions in the wastewater in accordance with the requirements of the "Electroplating Pollutant Discharge Standard" (GB21900-2008); (2) reducing operating costs and increasing the reuse rate of electroplating wastewater on the basis of meeting the standards; and (3) realizing the resource utilization of heavy metals / precious metals in electroplating wastewater, turning it into "treasure". The traditional treatment processes for electronic wastewater at home and abroad mainly include chemical precipitation, ion exchange, membrane separation, electrolysis, adsorption, and biological treatment, but these methods have certain limitations. Precipitation requires a large amount of chemical reagents, has little effect on the removal of chloride ions and organic matter, and produces a large amount of chemical sludge, increasing treatment costs. Biological treatment requires a high influent concentration (CODcr<1000mg / L), so the wastewater needs to be pretreated or diluted, and the hydraulic retention time is long (HRT>16h). Adsorption methods require a large amount of adsorbent, have low treatment efficiency, high operating costs, and are prone to clogging. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide an electrolytic adsorption device that is low in cost, has unrestricted requirements for the treatment of chlorine-containing electronic wastewater, and can effectively remove COD and / or has a high heavy metal recovery rate.

[0008] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0009] This invention provides an electrolytic adsorption device, comprising alternating parallel anodes and cathodes;

[0010] The anode includes an anode substrate and an anode material coated on the surface of the anode substrate; the anode substrate includes a titanium foil and a titanium dioxide nanotube layer on the surface of the titanium foil, the titanium dioxide nanotube layer being a three-dimensional array structure; the anode material is a composite material of SnO2, Sb and RuO2;

[0011] The cathode includes a cathode substrate and a cathode material coated on the surface of the cathode substrate, wherein the cathode material is a mixture of carbon-based materials and iron oxide.

[0012] Preferably, the alternating parallel arrangement is repeated 3 times.

[0013] Preferably, the mass ratio of the anode material to the anode substrate is (1-10):100;

[0014] The titanium dioxide nanotubes in the anode substrate have a length of 0.2–41 μm, an outer diameter of 10–100 nm, and a wall thickness of 10–20 nm.

[0015] Preferably, the mass ratio of SnO2, Sb and RuO2 in the composite material of SnO2, Sb and RuO2 is 70:10:20.

[0016] Preferably, the anode preparation process includes the following steps:

[0017] Using titanium foil as the working anode, platinum sheet as the cathode, and a solution containing fluoride ions as the electrolyte, an anodizing reaction is carried out, followed by heat treatment to obtain the anode substrate;

[0018] Preparation of precursor solution;

[0019] After the precursor solution is sprayed onto the surface of the anode substrate, thermal decomposition is performed to obtain the anode.

[0020] Preferably, the concentration of fluoride ions in the electrolyte is 0.2–2 mg / L;

[0021] The voltage for the anodic oxidation reaction is 10–30V, and the time is 2 hours.

[0022] The heat treatment temperature is 400–600℃, and the holding time is 3 hours.

[0023] Preferably, the mass ratio of carbon-based material to iron oxide in the cathode material is 100:(2-10);

[0024] The carbon-based material includes one or more of activated carbon, carbon nanotubes, and carbon black.

[0025] Preferably, the cathode fabrication process includes the following steps:

[0026] The cathode is obtained by coating a dispersion containing iron oxide and carbon-based materials onto the surface of a cathode substrate.

[0027] The present invention also provides the application of the electrolytic adsorption device described above in the treatment of chlorine-containing electronic wastewater.

[0028] Preferably, the method of application includes the following steps:

[0029] The chlorine-containing electronic wastewater is passed into the electrolytic adsorption device for treatment.

[0030] Preferably, the flow rate of the chlorine-containing electronic wastewater is 0.1–2 mL / min;

[0031] The operating current of the process is 2–20 mA / cm. 2 The voltage is 2V.

[0032] This invention provides an electrolytic adsorption device, comprising an alternating parallel anode and a cathode; the anode includes an anode substrate and an anode material coated on the surface of the anode substrate; the anode substrate includes a titanium foil and a titanium dioxide nanotube layer on the surface of the titanium foil, the titanium dioxide nanotube layer being a three-dimensional array structure; the anode material is a composite material of SnO2, Sb, and RuO2; the cathode includes a cathode substrate and a cathode material coated on the surface of the cathode substrate, the cathode material being a mixture comprising carbon-based materials and iron(III) oxide. The electrolytic adsorption device of this invention uses a novel titanium-based anode (comprising a substrate with a three-dimensional porous structure composed of a titanium dioxide nanotube framework and a composite material of SnO2, Sb, and RuO2 coated on the surface of the substrate) to adsorb Cl from a solution. - This process generates chlorine gas, a highly oxidizing agent, and its hydrolysis product HClO, thereby degrading organic pollutants and effectively solving the problem of high concentrations of recalcitrant organic matter in electronic wastewater. This enables rapid degradation of organic matter, ultimately giving the anode advantages of long lifespan and high catalytic activity. Using a carbon-based material coated with iron(III) oxide as the cathode, the unique lattice structure and redox properties of iron(III) oxide allow for selective adsorption of heavy metal ions such as copper, zinc, and lead. Compared to mainstream carbon-based electrode materials, this overcomes the problem of non-selectivity for multiple ions, improving the adsorption of relatively low concentrations of heavy metal ions (Cu, zinc, and lead). 2+ The adsorption and separation efficiency of ). Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the electrolytic adsorption device of the present invention; wherein, 1 is the water inlet, 2 is the water outlet, 3 is the electrochemical workstation, 4 is the anode, 5 is the cathode, 6 is the wire connecting the positive terminal of the power supply and the anode, and 7 is the wire connecting the negative terminal of the power supply and the cathode.

[0034] Figure 2 This is a schematic diagram of the cathode preparation process in the electrolytic adsorption device of the present invention;

[0035] Figure 3 This is a SEM image of the titanium dioxide nanotube layer on the surface of the anode substrate described in Example 1.

[0036] Figure 4 The adsorption-desorption isotherm and pore size distribution curve of the anode substrate described in Example 1 are shown. Detailed Implementation

[0037] like Figure 1 As shown, the present invention provides an electrolytic adsorption device, comprising an anode and a cathode arranged alternately in parallel.

[0038] The anode includes an anode substrate and an anode material coated on the surface of the anode substrate; the anode substrate includes a titanium foil and a titanium dioxide nanotube layer on the surface of the titanium foil, the titanium dioxide nanotube layer being a three-dimensional array structure; the anode material is a composite material of SnO2, Sb and RuO2;

[0039] The cathode includes a cathode substrate and a cathode material coated on the surface of the cathode substrate, wherein the cathode material is a mixture of carbon-based materials and iron oxide.

[0040] In this invention, unless otherwise specified, all raw materials used in the preparation are commercially available products well known to those skilled in the art.

[0041] In this invention, the alternating parallel arrangement is preferably repeated 3 times (e.g., ...). Figure 3 (As shown).

[0042] In this invention, the length of the titanium dioxide nanotubes in the anode substrate is preferably 0.2 to 41 μm, the outer diameter of the titanium dioxide nanotubes is preferably 10 to 100 nm, and the wall thickness of the titanium dioxide nanotubes is preferably 10 to 20 nm.

[0043] In this invention, the mass ratio of the SnO2, Sb, and RuO2 composite material to the anode substrate is preferably (1-10):100. In embodiments of this invention, the mass ratio of the SnO2, Sb, and RuO2 composite material to the anode substrate can be 1:100, 5:100, or 10:100.

[0044] In this invention, the preferred mass ratio of SnO2, Sb and RuO2 in the composite material of SnO2, Sb and RuO2 is 70:10:20.

[0045] In this invention, the anode preparation process preferably includes the following steps:

[0046] Using titanium foil as the working anode, platinum sheet as the cathode, and a solution containing fluoride ions as the electrolyte, an anodizing reaction is carried out, followed by heat treatment to obtain the anode substrate;

[0047] Preparation of precursor solution;

[0048] After the precursor solution is sprayed onto the surface of the anode substrate, thermal decomposition is performed to obtain the anode.

[0049] This invention uses titanium foil as the working anode, platinum sheet as the cathode, and a solution containing fluoride ions as the electrolyte. After anodizing, the anode substrate is obtained through heat treatment.

[0050] The present invention does not impose any special limitations on the titanium foil and platinum sheet; any titanium foil and platinum sheet known to those skilled in the art can be used.

[0051] In this invention, the concentration of fluoride ions in the fluoride-containing solution is preferably 0.2 to 2 mg / L.

[0052] In this invention, the solute in the electrolyte is preferably ammonium fluoride and / or sodium fluoride. When the solute is ammonium fluoride and sodium fluoride, this invention does not impose any special limitation on the ratio of ammonium fluoride and sodium fluoride; they can be mixed in any ratio. In an embodiment of this invention, the solute can be ammonium fluoride.

[0053] In this invention, the solvent in the electrolyte is preferably one or more of water, dimethyl sulfoxide, and ethylene glycol. When the solvent is two or more of the above-mentioned specific selections, this invention does not impose any special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio. In an embodiment of this invention, the solvent can be water.

[0054] In this invention, the voltage of the anodizing reaction is preferably 10-30V, and the time is preferably 2h.

[0055] In this invention, during the anodic oxidation reaction, fluoride ions participate in the reaction under the influence of an electric field, undergoing a series of chemical changes with the titanium foil and gradually growing titanium dioxide nanotubes on the surface of the titanium foil. This invention can control the three-dimensional structure of the titanium dioxide nanotubes by altering the concentration of fluoride ions and the voltage, thus affecting the reaction rate and reaction pathway.

[0056] In this invention, the heat treatment temperature is preferably 400–600°C, and the holding time is preferably 3 hours. In this invention, the heat treatment is preferably carried out in a nitrogen atmosphere. In this invention, the heat treatment can improve the purity of the electrode material, enhance its stability and density, and improve its electrochemical performance, which is beneficial for enhancing the electrode's ability to adsorb heavy metal ions and remove organic matter.

[0057] The method for preparing the anode described in this invention also includes preparing a precursor solution.

[0058] In this invention, the solutes in the precursor solution preferably include SnCl4, SbCl3 and RuCl4.

[0059] In this invention, the solvent in the precursor solution is preferably water.

[0060] In this invention, the concentration of SnCl4 in the precursor solution is preferably 15 mg / L, the concentration of SbCl3 in the precursor solution is preferably 2.32 mg / L, and the concentration of RuCl4 in the precursor solution is preferably 4.47 mg / L.

[0061] After obtaining the anode substrate and the precursor solution, the present invention sprays the precursor solution onto the surface of the anode substrate and then performs thermal decomposition to obtain the anode.

[0062] During the spraying process, the temperature of the anode substrate is preferably 300°C. In this invention, the spraying rate of the precursor solution is preferably 5 psi. In this invention, the thermal decomposition temperature is preferably 500°C, and the time is preferably 10 min. In this invention, the thermal decomposition is preferably carried out in an oxidizing atmosphere.

[0063] After the thermal decomposition is completed, the present invention preferably further includes sequentially repeating the above-described spraying and thermal decomposition processes. The present invention does not impose any particular limitation on the number of repetitions; any number of repetitions well known to those skilled in the art can be used, and the mass ratio of the anolyte material on the anode substrate surface to the anode substrate can satisfy the above-described requirements.

[0064] In this invention, the cathode substrate is preferably a graphite composite plate. This invention does not impose any special limitations on the type and composition of the graphite composite plate; types and compositions well-known to those skilled in the art can be used.

[0065] In this invention, the carbon-based material preferably includes one or more of activated carbon, carbon nanotubes, and carbon black. When the carbon-based material is two or more of the above-mentioned specific selections, this invention does not impose any special limitation on the ratio of the above-mentioned specific substances, and they can be mixed in any ratio. In an embodiment of this invention, the carbon-based material can be activated carbon.

[0066] In this invention, the preferred mass ratio of iron(III) oxide to carbon-based material in the cathode material is (2-10):100. In embodiments of this invention, the mass ratio of iron(III) oxide to carbon-based material can be 2:100, 5:100, or 10:100.

[0067] like Figure 2As shown, in this invention, the method for preparing the cathode preferably includes the following steps:

[0068] The cathode is obtained by coating a dispersion containing iron oxide and carbon-based materials onto the surface of a cathode substrate.

[0069] In this invention, the concentration of iron(III) oxide in the dispersion containing iron(III) oxide and carbon-based materials is preferably 0.2 g / L. In this invention, the mass ratio of iron(III) oxide to carbon-based materials in the dispersion containing iron(III) oxide and carbon-based materials is preferably (2-10):100. In this invention, the solvent in the dispersion containing iron(III) oxide and carbon-based materials is preferably dimethylformamide (DMF). In this invention, the dispersion containing iron(III) oxide and carbon-based materials also preferably includes a binder; the mass concentration of the binder in the dispersion containing iron(III) oxide and carbon-based materials is preferably 5 wt%. In this invention, the binder preferably includes polyvinylidene fluoride (PVDF). In an embodiment of this invention, the carbon-based material in the dispersion containing iron(III) oxide and carbon-based materials is activated carbon.

[0070] In this invention, the preparation process of the dispersion containing iron oxide and carbon-based materials preferably includes: adding the carbon-based material to a solvent and a binder simultaneously, then adding iron oxide, and mixing under stirring conditions. This invention does not impose any special limitations on the stirring process; any process well-known to those skilled in the art can be used. In embodiments of this invention, the stirring temperature can be room temperature, and the stirring time can be 4 hours.

[0071] In this invention, the coating method is preferably drop coating. This invention does not impose any special limitations on the drop coating process, and any process known to those skilled in the art can be used.

[0072] After the coating is completed, the present invention preferably includes drying. The present invention does not impose any special limitations on the drying process; any process well-known to those skilled in the art can be used. In an embodiment of the present invention, the drying is specifically vacuum drying, and the vacuum drying temperature can be 60°C and the time can be 24 hours.

[0073] In this invention, the spacing between adjacent anodes and cathodes is preferably 1 cm; the thickness of the anode is preferably 0.5 cm, and the thickness of the cathode is preferably 0.1 cm; the effective area when adjacent anodes and cathodes are arranged in parallel is preferably 10 cm × 5 cm.

[0074] In this invention, the anodes are preferably connected in series, the cathodes are preferably connected in series, and a power source is preferably connected between the anodes and cathodes.

[0075] In this invention, the anode and cathode are preferably placed in a reactor made of plexiglass, with an outlet at the bottom of one side wall and an inlet at the top of the other side wall.

[0076] The working principle of the electrolytic adsorption device is as follows: when the anode is connected to the positive terminal of the power supply and the cathode is connected to the negative terminal of the power supply for forward charging, the active sites on the anode surface will adsorb Cl from the solution. - The Cl2 produced and its hydrolysis product HClO have strong oxidizing properties and can degrade organic pollutants, as shown in Formulas 1 and 2, where M represents a metal element:

[0077]

[0078] Meanwhile, heavy metal ions (Cu) in the wastewater 2+ Zn 2+ Ni 2+ (etc.) are adsorbed onto the cathode surface and enriched;

[0079] When the adsorption is saturated, the anode is connected to the negative terminal of the power supply and the cathode is connected to the positive terminal of the power supply for reverse charging. The previous cathode becomes the anode, so the previously adsorbed heavy metals are desorbed into the concentrate, completing the resource recovery and electrode regeneration.

[0080] The present invention also provides the application of the electrolytic adsorption device described above in the treatment of chlorine-containing electronic wastewater.

[0081] In this invention, the method of application preferably includes the following steps:

[0082] The chlorine-containing electronic wastewater is passed into the electrolytic adsorption device for treatment.

[0083] In this invention, the COD concentration in the chlorinated electronic wastewater is preferably 200 mg / L, the chloride ion concentration is preferably 5 mmol / L, and the Cu... 2+ The preferred concentration of ions is 50 mg / L.

[0084] In this invention, the flow rate of the chlorine-containing electronic wastewater is preferably 0.1–2 mL / min, more preferably 0.1 mL / min, 0.5 mL / min, or 2 mL / min. In this invention, the operating current for the treatment is preferably 2–20 mA / cm². 2 More preferably 2mA / cm 2 5mA / cm 2 10mA / cm 2 Or 20mA / cm 2 In an embodiment of the present invention, the operating current of the process can be 5 mA / cm. 2 .

[0085] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0086] Example 1

[0087] Using titanium foil as the working anode and a platinum-tailed cathode, and an ethylene glycol aqueous solution containing ammonium fluoride (fluoride ion concentration of 2 mg / L, volume ratio of ethylene glycol to water of 30:70) as the electrolyte, an anodic oxidation reaction was performed (voltage 20V, time 2h). Following this, heat treatment was carried out under an inert atmosphere and at 400℃ to obtain an anode substrate (comprising titanium foil and a titanium dioxide nanotube layer formed on the surface of the titanium foil, wherein the titanium dioxide nanotube layer has a three-dimensional porous structure, and the length of the titanium dioxide nanotubes is 1–41 μm, the outer diameter is 10–100 nm, and the wall thickness is 10–20 nm). The anode specific surface area is approximately 28.155 μm. 2 / g;

[0088] SnCl4, SbCl3, RuCl4 and water were mixed to obtain a mixed solution (where the concentration of SnCl4 was 15 mg / L, the concentration of SbCl3 was 2.32 mg / L, the concentration of RuCl4 was 4.47 mg / L, and the mass ratio of SnO2, Sb and RuO2 was 70:10:20).

[0089] After spraying 10 mL of the mixture onto the surface of a titanium foil at 300 °C at a speed of 5 psi, the foil was placed in a muffle furnace and thermally decomposed at 500 °C for 10 min in an oxidizing atmosphere. The above spraying and sintering process was repeated 5 times to obtain an anode (approximately 0.5 cm thick, comprising a composite material of SnO2, Sb, and RuO2 including the anode substrate and the surface of the anode substrate; the mass ratio of the SnO2, Sb, and RuO2 composite material to the mass of the anode substrate is approximately 1:100).

[0090] Using a graphite composite plate as the cathode substrate, activated carbon was added to dimethylformamide, followed by polyvinylidene fluoride, and then iron oxide was added. The mixture was stirred at room temperature for 4 hours to obtain a dispersion containing iron oxide and activated carbon (the concentration of iron oxide was 0.2 g / L, the concentration of activated carbon was 10 g / L, and the concentration of polyvinylidene fluoride was 5 wt%).

[0091] The dispersion containing iron oxide and activated carbon was uniformly coated on the surface of a graphite composite plate and dried in a vacuum drying oven at 60°C for 24 hours to obtain a cathode (thickness of 0.1 cm).

[0092] The anodes and cathodes are stacked and repeated three times. The distance between adjacent anodes and cathodes is 1 cm. The effective contact area when adjacent anodes and cathodes are arranged in parallel is 10 cm × 5 cm. The anodes are connected in series, and the cathodes are connected in series. A power source is connected between the anodes and cathodes. The reactor is placed in a reactor made of plexiglass. The bottom of one side wall of the reactor is provided with a water inlet, and the top of the other side wall is provided with a water outlet.

[0093] Figure 3 The images show SEM images of the titanium dioxide nanotube layer, where a is a top view of the nanotube array (magnified 15000x) and b is a side view of the nanotube array (magnified 30000x). Figure 3 It can be seen that the titanium dioxide nanotube layer has a three-dimensional array structure;

[0094] Figure 4 The adsorption-desorption isotherms and pore size distribution curves of the anode substrate are given by... Figure 4 As can be seen from the adsorption isotherms, the adsorption amount gradually increases with increasing relative pressure; at lower relative pressures, the increase in adsorption is relatively slow; and when the relative pressure approaches 1, the adsorption amount increases rapidly. The desorption isotherms show a similar trend to the adsorption process, but at higher relative pressures, the desorption curve does not coincide with the adsorption curve, indicating the presence of a mesoporous structure in the material. Figure 4 The pore size distribution curve was obtained through the analysis and calculation of the adsorption-desorption isotherm. It further reveals the details of the pore structure of the anode substrate, namely, that there are relatively more pores with a pore size of about 20 nm, which contribute significantly to the pore volume; in the region with a pore size of less than 20 nm, the curve rises rapidly, indicating that there are also some distributions of smaller pore sizes, but their numbers are relatively small; when the pore size is greater than 20 nm, the curve gradually declines, indicating that the number of pores gradually decreases as the pore size increases.

[0095] Example 2

[0096] Referring to Example 1, the difference is that the concentration of fluoride ions in the ethylene glycol aqueous solution containing ammonium fluoride is 0.2 mg / L.

[0097] Example 3

[0098] Referring to Example 1, the difference is that the concentration of fluoride ions in the ethylene glycol aqueous solution containing ammonium fluoride is 1 mg / L.

[0099] Example 4

[0100] Referring to Example 1, the difference is that the voltage for the anodic oxidation reaction is 10V.

[0101] Example 5

[0102] Referring to Example 1, the difference is that the voltage for the anodizing reaction is 30V.

[0103] Example 6

[0104] Referring to Example 1, the difference is that after the oxidation reaction is completed, heat treatment is performed under an inert atmosphere and at 500°C.

[0105] Example 7

[0106] Referring to Example 1, the difference is that after the oxidation reaction is completed, heat treatment is performed under an inert atmosphere and at 600°C.

[0107] Example 8

[0108] Referring to Example 1, the difference is that the mass ratio of the composite material of SnO2, Sb and RuO2 in the anode to the mass ratio of the anode substrate is 5:100.

[0109] Example 9

[0110] Referring to Example 1, the difference is that the mass ratio of the composite material of SnO2, Sb and RuO2 in the anode to the mass ratio of the anode substrate is 10:100.

[0111] Example 10

[0112] Referring to Example 1, the difference is that the mass ratio of iron oxide to activated carbon in the dispersion containing iron oxide and activated carbon is 4:100.

[0113] Example 11

[0114] Referring to Example 1, the difference is that the mass ratio of iron oxide to activated carbon in the dispersion containing iron oxide and activated carbon is 6:100.

[0115] Example 12

[0116] Referring to Example 1, the difference is that the mass ratio of iron oxide to activated carbon in the dispersion containing iron oxide and activated carbon is 10:100.

[0117] Comparative Example 1

[0118] Referring to Example 1, the difference is that pure titanium foil is used as the anode.

[0119] Comparative Example 2

[0120] Referring to Example 1, the difference is that the amount of iron(III) oxide added during the cathode preparation process is 0.

[0121] Application Examples 1-3

[0122] Chlorine-containing electronic wastewater (COD concentration of 200 mg / mL, copper ion concentration of 50 mg / L, and chloride ion concentration of 5 mmol / mL) was introduced into the chlorine-containing electronic wastewater described in Examples 1-13 and Comparative Examples 1-2 at flow rates of 0.1 mL / s (Application Example 1), 0.5 mL / s (Application Example 2), or 2 mL / s (Application Example 3), respectively, for treatment (the operating current for treatment was 5 mA / cm). 2 The processed data are shown in Tables 1-3:

[0123] Table 1 shows the test results of Application Example 1.

[0124]

[0125]

[0126] Table 2 shows the test results of Application Example 2.

[0127]

[0128]

[0129] Table 3 shows the test results of Application Example 3.

[0130]

[0131] As shown in Tables 1-3, the electrolytic adsorption devices described in this invention effectively adsorb and remove pollutants such as copper, COD, and chloride ions. Chlorine-containing electronic wastewater often contains both organic matter and heavy metals; therefore, it is recommended to prioritize the optimized conditions of Example 1 or Example 9, as the differences are minimal and the overall effect is superior to other conditions. The removal rate of the above pollutants is relatively high at a water flow rate of 0.5 mL / min, especially with high current efficiency. When the water flow rate increases to 2 mL / min, the removal rate decreases. Furthermore, the content of the coating material on the anode surface and the content of iron(III) oxide on the cathode surface have a significant impact on the removal of the corresponding pollutants; within the experimental range, higher contents result in higher removal rates.

[0132] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An electrolytic adsorption device, characterized in that, This includes alternating parallel anodes and cathodes; The anode includes an anode substrate and an anode material coated on the surface of the anode substrate; the anode substrate includes a titanium foil and a titanium dioxide nanotube layer on the surface of the titanium foil, the titanium dioxide nanotube layer being a three-dimensional array structure; the anode material is a composite material of SnO2, Sb and RuO2; The cathode includes a cathode substrate and a cathode material coated on the surface of the cathode substrate, wherein the cathode material is a mixture of carbon-based materials and iron oxide; The mass ratio of SnO2, Sb and RuO2 in the composite material of SnO2, Sb and RuO2 is 70:10:20; The anode preparation process includes the following steps: Using titanium foil as the working anode, platinum sheet as the cathode, and a solution containing fluoride ions as the electrolyte, an anodizing reaction is carried out, followed by heat treatment to obtain the anode substrate; Prepare a precursor solution; the solutes in the precursor solution include SnCl4, SbCl3, and RuCl4. The solvent in the precursor solution is water. After the precursor solution is sprayed onto the surface of the anode substrate, thermal decomposition is performed to obtain the anode; The mass ratio of carbon-based material to iron oxide in the cathode material is 100:(2~10). The carbon-based material includes one or more of activated carbon, carbon nanotubes, and carbon black.

2. The electrolytic adsorption device as described in claim 1, characterized in that, The alternating parallel arrangement is repeated 3 times.

3. The electrolytic adsorption device as described in claim 1, characterized in that, The mass ratio of the anode material to the anode substrate is (1~10):100; The titanium dioxide nanotubes in the anode substrate have a length of 0.2~41μm, an outer diameter of 10~100nm, and a wall thickness of 10~20nm.

4. The electrolytic adsorption device as described in claim 1, characterized in that, The concentration of fluoride ions in the electrolyte is 0.2~2 mg / L; The voltage for the anodic oxidation reaction is 10~30V, and the time is 2h; The heat treatment temperature is 400~600℃, and the holding time is 3h.

5. The electrolytic adsorption device as described in claim 1, characterized in that, The cathode preparation process includes the following steps: The cathode is obtained by coating a dispersion containing iron oxide and carbon-based materials onto the surface of a cathode substrate.

6. The application of the electrolytic adsorption device according to any one of claims 1 to 5 in the treatment of chlorine-containing electronic wastewater, characterized in that, The method of application includes the following steps: The chlorine-containing electronic wastewater is passed into the electrolytic adsorption device for treatment.

7. The application as described in claim 6, characterized in that, The flow rate of the chlorine-containing electronic wastewater is 0.1~2 mL / min; The operating current of the process is 2~20mA / cm. 2 The voltage is 2V.

Images