Apparatus and method for sewage treatment and re-use

Abstract

This disclosure relates to an apparatus and method for wastewater treatment and reuse. The apparatus includes a water tank, a cathode, a porous anode plate integrating photothermal conversion and electrocatalytic anode functions, a transparent condenser shroud, and a water collection tank. A photothermal conversion layer is provided on the first main surface of the porous anode plate, and the second main surface of the porous anode plate is in contact with the water in the water tank. The cathode is disposed in the water. The condenser shroud is disposed above the water tank to condense the water evaporated through the porous anode plate. The water collection tank is used to collect the water condensed by the condenser shroud. The water collection tank includes a reused water outlet. The apparatus and method provided by this disclosure can further improve wastewater treatment efficiency and reduce energy consumption, and can also achieve wastewater desalination and reuse.

Description

Technical Field

[0001] This disclosure relates to the field of wastewater treatment technology, and more specifically, to an apparatus and method for wastewater treatment and reuse. Background Technology

[0002] To achieve zero or near-zero wastewater discharge, wastewater concentration and desalination technology is crucial. Currently, wastewater desalination processes primarily employ membrane separation, multi-effect evaporation, and MVR (Multi-Volume Reduction) methods, which involve high investment and energy consumption (0.2 t steam / m³). 3 Water, or 40 kWh of electricity / m 3 Wastewater treatment is costly, especially for concentrated wastewater. Therefore, there is a need to develop low-cost concentration and desalination processes. Solar-driven interfacial evaporation technology is low-cost, highly efficient, and has great application potential. Existing solar thermal evaporation and concentration devices and processes still suffer from poor concentration effects and high energy consumption; furthermore, they are difficult to reuse desalinated wastewater. Summary of the Invention

[0003] The purpose of this disclosure is to provide an apparatus and method for wastewater treatment and reuse, which can further improve the wastewater treatment effect, reduce energy consumption, and realize the desalination and reuse of wastewater.

[0004] To achieve the above objectives, the first aspect of this disclosure provides a wastewater treatment and reuse apparatus, comprising a water tank, a cathode, a porous anode plate integrating photothermal conversion and electrocatalytic anode, a transparent condenser shroud, and a water collection tank; a photothermal conversion layer is provided on the first main surface of the porous anode plate, and the second main surface of the porous anode plate is in contact with the water in the water tank; the cathode is disposed in the water; the condenser shroud is disposed above the water tank for condensing the water evaporated through the porous anode plate; the water collection tank is used to collect the water condensed by the condenser shroud; the water collection tank includes a reused water outlet.

[0005] Optionally, the condenser shroud includes a first sidewall, a second sidewall, a third sidewall, and a fourth sidewall; the water tank includes a fifth sidewall, a sixth sidewall, a seventh sidewall, and an eighth sidewall; the first sidewall is correspondingly disposed above the fifth sidewall, the second sidewall is correspondingly disposed above the sixth sidewall, and the third sidewall is correspondingly disposed above the seventh sidewall; With the eighth side wall of the water tank as the boundary, the fourth side wall of the condenser shroud is located outside the eighth side wall of the water tank, and the bottom of the fourth side wall of the condenser shroud is connected to the top of the eighth side wall of the water tank through a base plate; preferably, the bottom of the fourth side wall of the condenser shroud and the top of the eighth side wall of the water tank are located on the same plane. Preferably, the top of the eighth side wall of the water tank is provided with a baffle, the baffle has a gap with the top of the condenser shroud, the baffle has a gap with the fourth side wall of the condenser shroud, and the baffle, the fourth side wall of the condenser shroud and the bottom plate form the water collection tank; the fourth side wall of the condenser shroud is provided with the recycled water outlet.

[0006] Optionally, the fourth sidewall of the condenser shroud is disposed opposite to the third sidewall; the height of the fourth sidewall is lower than the height of the third sidewall, so that the top wall of the condenser shroud is inclined downward along the direction from the third sidewall to the fourth sidewall; Preferably, the inclination angle between the top wall and the horizontal direction is 5~80°, more preferably 15~60°.

[0007] Optionally, the photothermal conversion layer is a black photothermal conversion coating; optionally, the photothermal conversion coating includes a photothermal conversion material, which is selected from one or more of polypyrrole, graphene, black chromium, and carbon nanotubes; preferably, carbon nanotubes; Optionally, the photothermal conversion coating further includes a binder selected from one or more of chitosan, water glass, and epoxy resin; preferably, the photothermal conversion coating includes carbon nanotubes and chitosan; more preferably, based on the total weight of the photothermal conversion coating, the content of carbon nanotubes is 1-15% by weight, preferably 2-8% by weight. More preferably, the thickness of the photothermal conversion layer is 0.001~2mm, more preferably 0.01~0.5mm.

[0008] Optionally, the porous anode plate is made of one or more of titanium suboxide, stainless steel, and graphite; preferably titanium suboxide.

[0009] Optionally, the thickness of the porous anode plate is 0.1~5mm, preferably 0.5~2mm; the openings on the porous anode plate are through-holes; preferably, the aperture of the openings on the porous anode plate is 0.01~1mm, preferably 0.05~0.1mm.

[0010] Optionally, the water tank is an open cuboid, and the ratio of the length to the width of the water tank is 0.5 to 10:1, preferably 1 to 3:1; the ratio of the length to the height of the water tank is 0.1 to 10:1, preferably 0.5 to 5:1.

[0011] Optionally, the distance between the cathode and the porous anode plate is 5~100mm, preferably 10~30mm; Optionally, the cathode is selected from one of graphite electrode, activated carbon fiber electrode and metal electrode; preferably, it is a graphite electrode.

[0012] A second aspect of this disclosure provides a method for wastewater treatment using the apparatus described in the first aspect of this disclosure, comprising the following steps: S1. Allow the wastewater to be treated to enter the water tank of the device; S2. Connect voltage to the porous anode plate and cathode respectively to perform electrocatalytic treatment on the wastewater to be treated in the water tank; expose the photothermal conversion layer of the porous anode plate to sunlight; S3. The water evaporated through the porous anode plate is condensed in the condenser hood, collected in the water collection tank, and reused through the recycled water outlet.

[0013] Optionally, the pH of the wastewater to be treated is 5-10, preferably 6-9; TDS is 0.1-300000 mg / L, preferably 1-100000 mg / L; and COD is 30-300000 mg / L, preferably 200-50000 mg / L.

[0014] Optionally, the current density between the porous anode plate and the cathode is 0.1~1000 A / m. 2 Preferably 1~500A / m 2 More preferably 2~50 A / m 2 ; The residence time of the wastewater to be treated in the water tank is 0.1~240h, preferably 0.5~120h.

[0015] Optionally, the method further includes: At least a portion of the treated wastewater is returned to the water tank for further treatment; Preferably, the wastewater recirculation ratio is 0.1 to 20:1, more preferably 0.5 to 5:1.

[0016] Through the above technical solution, this disclosure provides a wastewater treatment and reuse apparatus and method. In the apparatus provided by this disclosure, a photothermal conversion layer is provided on one main surface of the porous anode plate, and the other main surface is directly immersed in water. The photothermal conversion layer can absorb sunlight and convert solar energy into heat energy to heat the water in the tank, thereby improving the water evaporation efficiency and reducing energy consumption. The channels on the porous anode plate also facilitate the evaporation of water in the tank. A condenser hood is provided in the apparatus to condense the water evaporated through the channels into water, which is then collected by a collection tank for subsequent reuse. Furthermore, the wastewater to be treated can undergo an electrocatalytic reaction between the anode and cathode to reduce the COD of the wastewater, thereby ensuring the quality of the reused water. Using the apparatus provided by this disclosure can further improve the treatment effect of the wastewater to be treated, reduce energy consumption, and realize wastewater reuse and green technology.

[0017] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of a wastewater treatment device provided in this disclosure.

[0019] Figure Labels 1-Inlet pipe, 2-Sewage outlet pipe, 3-Return pipe, 4-Water tank, 5-Porous sub-titanium oxide plate (porous anode plate), 6-Cathode, 7-Voltage stabilizing power supply, 8-Condensation hood, 9-Water collection tank, 10-Reclaimed water outlet pipe. Detailed Implementation

[0020] The following provides a detailed description of specific embodiments of this disclosure. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit this disclosure. The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values; these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0021] The first aspect of this disclosure provides a wastewater treatment and reuse apparatus, comprising a water tank, a cathode, a porous anode plate integrating photothermal conversion and electrocatalytic anode, a transparent condenser shroud, and a water collection tank; a photothermal conversion layer is provided on a first main surface of the porous anode plate, and the second main surface of the porous anode plate is in contact with the water in the water tank; the cathode is disposed in the water; the condenser shroud is disposed above the water tank for condensing water evaporated through the porous anode plate; the water collection tank is used to collect the water condensed by the condenser shroud; the water collection tank includes a reused water outlet.

[0022] This disclosure provides a wastewater treatment apparatus. One main surface of the porous anode plate of the apparatus is provided with a photothermal conversion layer, while the other main surface is directly immersed in water. The photothermal conversion layer absorbs sunlight and converts solar energy into heat energy to heat the water in the tank, improving water evaporation efficiency. The channels on the porous anode plate also facilitate evaporation of water from the tank, thereby reducing energy consumption. A condenser hood is installed in the apparatus to condense the water evaporated through the channels, and the condensed water is collected in a collection tank for subsequent reuse. Furthermore, the wastewater to be treated can undergo an electrocatalytic reaction between the anode and cathode to reduce the COD of the wastewater, thus ensuring the quality of the reused water. Using the apparatus provided by this disclosure can further improve the treatment effect of wastewater, reduce energy consumption, and realize wastewater reuse and green technology.

[0023] In a preferred embodiment, such as Figure 1 As shown, the condenser shroud includes a first sidewall, a second sidewall, a third sidewall, and a fourth sidewall; the water tank includes a fifth sidewall, a sixth sidewall, a seventh sidewall, and an eighth sidewall; the first sidewall is correspondingly disposed above the fifth sidewall, the second sidewall is correspondingly disposed above the sixth sidewall, and the third sidewall is correspondingly disposed above the seventh sidewall; With the eighth side wall of the water tank as the boundary, the fourth side wall of the condenser shroud is located outside the eighth side wall of the water tank, and the bottom of the fourth side wall of the condenser shroud is connected to the top of the eighth side wall of the water tank through a base plate; preferably, the bottom of the fourth side wall of the condenser shroud and the top of the eighth side wall of the water tank are located on the same plane.

[0024] In a preferred embodiment, such as Figure 1 As shown, a baffle is provided on the top of the eighth side wall of the water tank. The baffle has a gap with the top of the condenser shroud and a gap with the fourth side wall of the condenser shroud. The baffle, the fourth side wall of the condenser shroud, and the bottom plate form the water collection tank. The recycled water outlet is provided on the fourth side wall of the condenser shroud.

[0025] In a preferred embodiment, the fourth sidewall of the condenser shroud is disposed opposite to the third sidewall; the height of the fourth sidewall is lower than the height of the third sidewall, so that the top wall of the condenser shroud is inclined downward along the direction from the third sidewall to the fourth sidewall. Preferably, the inclination angle between the top wall and the horizontal direction is 5~80°, more preferably 15~60°. In this embodiment, the inclined top wall of the condenser hood is more conducive to the flow of water into the collection tank after condensation.

[0026] In one specific embodiment, the wastewater treatment device further includes an inlet pipe 1, a wastewater outlet pipe 2, and a return pipe 3. The water tank 4 is provided with an inlet and a wastewater outlet. The inlet pipe 1 is connected to the inlet of the water tank 4, and the wastewater outlet pipe 2 is connected to the wastewater outlet of the water tank. One end of the return pipe 3 is connected to the wastewater outlet of the water tank 4, and the other end is connected to the inlet of the water tank 4, so as to return at least a portion of the wastewater from the outlet to the inlet for further treatment, thereby improving the wastewater concentration effect.

[0027] In one embodiment, the photothermal conversion layer is a black photothermal conversion coating; optionally, the photothermal conversion coating includes a photothermal conversion material, which is selected from one or more of polypyrrole, graphene, black chromium, and carbon nanotubes; preferably, carbon nanotubes; using the material of the photothermal conversion coating provided in this embodiment, especially the preferred material of the photothermal conversion coating, can achieve a better heat utilization effect and improve the evaporation efficiency of water.

[0028] In one specific embodiment, the photothermal conversion coating further includes a binder selected from one or more of chitosan, water glass, and epoxy resin; preferably, the photothermal conversion coating includes carbon nanotubes and chitosan; more preferably, based on the total weight of the photothermal conversion coating, the content of carbon nanotubes is 1-15% by weight, preferably 2-8% by weight. Using a photothermal conversion coating with the composition provided in this embodiment, especially a photothermal conversion coating with a preferred composition range, can achieve superior water evaporation effects. This disclosure obtains the photothermal conversion coating by applying a coating material to the photothermal conversion layer using conventional methods. The coating material includes a photothermal conversion material, a binder, and a solvent, and the solvent can be a conventional solvent type, such as water and ethanol.

[0029] In one specific embodiment, the photothermal conversion material layer is a black photothermal conversion material film. The use of a black film in this disclosure can further improve the photothermal conversion efficiency and moisture evaporation efficiency of the porous anode plate.

[0030] In a preferred embodiment, the thickness of the photothermal conversion layer is 0.001~2mm, including but not limited to 0.001mm, 0.005mm, 0.01mm, 0.05mm, 0.1mm, 0.2mm, 0.4mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, and 2.0mm; preferably 0.01~0.5mm, including but not limited to 0.01mm, 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, and 0.5mm. The photothermal conversion layer with the thickness of this embodiment, especially the preferred thickness, results in better photothermal conversion and water evaporation effects on the porous anode plate, thereby further improving the wastewater treatment effect.

[0031] In one embodiment, the porous anode plate is made of one or more of titanium suboxide, stainless steel, and graphite; titanium suboxide is preferred. Using the porous anode plate material of this embodiment is more beneficial for photothermal conversion and wastewater treatment.

[0032] In one embodiment, the thickness of the porous anode plate is 0.1~5mm, including but not limited to 0.1mm, 0.2mm, 0.4mm, 0.6mm, 0.8mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, and 5mm; preferably 0.5~2mm; the openings on the porous anode plate are through-holes; preferably, the aperture of the openings on the porous anode plate is 0.01~1mm, including but not limited to 0.01mm, 0.05mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, and 1mm, preferably 0.05~0.1mm, including but not limited to 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, and 0.1mm. The aperture range described in this embodiment enables the device to have excellent evaporation efficiency.

[0033] In one embodiment, the water tank is an open cuboid, and the ratio of the length to the width of the water tank is 0.5 to 10:1, including but not limited to 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1; preferably 1 to 3:1, including but not limited to 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1, 2:1, 2.2:1, 2.4:1, 2.6:1, 2.8:1, 3:1; the ratio of the length to the height of the water tank is 0.1 to 10:1, including but not limited to 0.1:1, 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1; preferably 0.5 to 5:1.

[0034] In one specific embodiment, the cathode is selected from graphite electrodes, activated carbon fiber electrodes, and metal electrodes; preferably, it is a graphite electrode. The device provided in this disclosure can use materials commonly used for cathodes in the art.

[0035] In one specific embodiment, the cathode can also be a porous cathode, with a thickness of 0.01~10mm, preferably 0.5~5mm; the openings on the cathode are through-holes; preferably, the aperture of the openings on the cathode is 0.001~2mm, more preferably 0.01~1mm. Using a porous cathode is beneficial to improving wastewater treatment efficiency.

[0036] In one specific implementation, such as Figure 1 As shown, the wastewater treatment device provided in this disclosure includes an inlet pipe 1, a wastewater outlet pipe 2, a return pipe 3, and a water tank 4. A porous anode plate 5 integrating photothermal conversion and electrocatalytic anode, an electrocatalytic porous cathode 6, and a voltage regulator 7 are placed on top of the water tank 4. One side of the porous anode plate 5 is coated with a black polypyrrole film (photothermal conversion layer), and the other side is immersed in water. Both the porous anode plate 5 and the electrocatalytic porous cathode 6 are connected to the voltage regulator 7. The water tank 4 is an open cuboid. The inlet pipe 1 is connected to the lower part of one side of the water tank 4, the wastewater outlet pipe 2 is connected to the upper part of the other side of the water tank 4, and the return pipe 3 is connected to both the inlet pipe 1 and the wastewater outlet pipe 2. A condenser hood 8 is located above the water tank 4. A water collection tank 9 is located below the inclined plate of the condenser hood 8, and a recycled water outlet pipe 10 is installed at the bottom of the water collection tank.

[0037] A second aspect of this disclosure provides a method for wastewater treatment and reuse using the apparatus described in the first aspect of this disclosure, comprising the following steps: S1. Allow the wastewater to be treated to enter the water tank of the device; S2. Connect voltage to the porous anode plate and cathode respectively to perform electrocatalytic treatment on the wastewater to be treated in the water tank; expose the photothermal conversion layer of the porous anode plate to sunlight; S3. The water evaporated through the porous anode plate is condensed in the condenser hood, collected in the water collection tank, and then discharged through the recycled water outlet for reuse.

[0038] This disclosure provides a wastewater treatment method using the wastewater concentration device provided herein. After the wastewater to be treated is introduced into the water tank of the device, electricity is applied to the anode and cathode, causing an electrocatalytic reaction between the anode and cathode to reduce the COD of the wastewater. A porous anode plate coated with a photothermal conversion layer absorbs solar energy on one side, converting the light energy into heat energy to heat the wastewater in the water tank. The wastewater evaporates through the pores of the anode plate. A condenser hood condenses the water evaporated through the porous anode plate into water, which is collected in a collection tank and then discharged through a recycled water outlet for reuse. This method can further improve the wastewater concentration effect, thereby reducing energy consumption, and the quality of the recycled water is also better.

[0039] In one embodiment, the wastewater to be treated has a pH of 5-10, preferably 6-9; a TDS of 0.1-300,000 mg / L, preferably 1-100,000 mg / L; a COD of 30-300,000 mg / L, preferably 200-50,000 mg / L; and a conductivity of 0.1-200,000 μS / cm, more preferably 1-100,000 μS / cm. The method provided in this disclosure can treat wastewater with high pollutant content.

[0040] In one embodiment, the current density between the porous anode plate and the cathode is 0.1~1000 A / m. 2 including but not limited to 0.1A / m 2 1A / m 2 10A / m 2 50A / m 2 100A / m 2 200A / m 2 300A / m 2 400A / m 2 500A / m 2 600A / m 2 700A / m 2 800A / m 2 900A / m 2 1000A / m 2 Preferably, the value is 1~500 A / m 2The residence time of the wastewater to be treated in the water tank is 0.1~240h, including but not limited to 0.1h, 0.5h, 1h, 5h, 10h, 50h, 100h, 150h, 200h, and 240h; preferably 0.5~120h. According to the treatment conditions of the wastewater to be treated provided in this embodiment, especially the preferred treatment conditions, a better treatment effect of the wastewater to be treated can be achieved, resulting in better quality reclaimed water.

[0041] In one embodiment, the method further includes: At least a portion of the treated wastewater is returned to the water tank for further treatment. This disclosure further improves wastewater treatment efficiency by returning at least a portion of the wastewater in the water tank to the tank for continued treatment.

[0042] In a preferred embodiment, the wastewater recirculation ratio is 0.1 to 20:1, including but not limited to 0.1:1, 0.5:1, 1:1, 2:1, 4:1, 6:1, 8:1, 10:1, 12:1, 14:1, 16:1, 18:1, and 20:1, preferably 0.5 to 5:1. Wastewater treatment according to the wastewater recirculation ratio provided in this embodiment can achieve better wastewater treatment results.

[0043] The present disclosure is further described in detail below through examples. All raw materials used in the examples are commercially available.

[0044] Example 1 use Figure 1 The wastewater treatment device shown is used for wastewater treatment. The device includes: a water tank, a porous anode plate integrating photothermal conversion and electrocatalytic anode, and a cathode. A photothermal conversion layer is provided on the first main surface of the porous anode plate, and the second main surface of the porous anode plate is in contact with the water in the water tank. The cathode is placed in the water. The photothermal conversion material layer of the photothermal conversion layer is a black carbon nanotube coating (obtained by conventional coating after uniform mixing of 40 mg carbon nanotubes and 1 mL chitosan solution), and the thickness of the resulting photothermal conversion layer is 0.1 mm. Based on the total weight of the photothermal conversion layer, the content of the photothermal conversion material (carbon nanotubes) is 4% by weight. The porous anode plate is made of titanium suboxide and has a thickness of 1mm. The openings on the porous anode plate are 0.1mm in diameter. The water tank is an open cuboid with dimensions of 100mm×50mm×50mm. The length-to-width ratio of the water tank is 2:1, and the length-to-height ratio is 2:1. The cathode is a graphite electrode, and the distance between the cathode and the porous anode plate is 15mm. The top wall of the condenser is inclined at an angle of 45° to the horizontal direction. The inlet pipe is connected to the lower part of one side of the water tank, and the sewage outlet pipe is connected to the upper part of the other side of the water tank. The two ends of the return pipe are connected to the inlet pipe and the sewage outlet pipe, respectively.

[0045] This embodiment treats high-salinity wastewater from a coal chemical plant. The wastewater has a pH of 7.5, a TDS of 106901 mg / L, and a COD of 477 mg / L. The treatment includes the following steps: The wastewater to be treated is introduced into the water tank of the device; The porous anode plate and cathode are respectively connected to voltage to electrocatalytically treat the wastewater in the water tank; the photothermal conversion layer of the porous anode plate is exposed to sunlight; the water evaporated through the porous anode plate is condensed in a condenser and collected in a water collection tank, then flows out through the recycled water outlet for reuse; at least a portion of the treated wastewater is returned to the water tank for further treatment; wherein the wastewater residence time in the water tank is 2 hours, the return ratio is 3:1, and the current density is 10 A / m³. 2 The measured evaporation efficiency was 1.52 kg / (m³). 2 h).

[0046] The treated recycled water (collection tank) had a TDS of 243 mg / L, a COD of 12 mg / L, and a conductivity of 310 μS / cm.

[0047] Comparative Example 1 This comparative example is identical to Example 1 in all other aspects, except that no power supply was applied, electrocatalytic oxidation was not performed, and the evaporation efficiency was measured to be 1.38 kg / (m³). 2 h).

[0048] The treated recycled water (collection tank) had a TDS of 502 mg / L, a COD of 420 mg / L, and a conductivity of 650 μS / cm.

[0049] Comparing Comparative Example 1 with Example 1, it can be seen that Comparative Example 1 did not perform electrocatalysis on the water in the tank, resulting in lower evaporation efficiency and higher TDS and COD of the recycled water. This indicates that the wastewater treatment and reuse apparatus and method provided in this disclosure in Example 1 can achieve higher evaporation efficiency, better energy consumption reduction, and better quality recycled water.

[0050] Comparative Example 2 This comparative example, based on the apparatus of Example 1, adds a common titanium dioxide plate anode (completely submerged in the water) to the middle of the water in the tank and connects it to a porous cathode in the tank for electrocatalysis; the porous anode plate for photothermal conversion is retained at the top of the tank, but no current is passed through it; the distance between the porous anode plate and the cathode at the top of the tank is 15 mm, and the current density is 10 A / m. 2 The electrodes at the top of the water tank were activated, and the evaporation efficiency was measured to be 1.41 kg / (m³). 2 h).

[0051] The treated recycled water (collection tank) had a TDS of 321 mg / L, a COD of 182 mg / L, and a conductivity of 483 μS / cm.

[0052] Comparing Comparative Example 2 with Example 1, it can be seen that Comparative Example 2 uses conventionally configured anodes and cathodes for electrocatalysis, and the porous anode plate for photothermal conversion at the top is only used for evaporation. The evaporation efficiency of this comparative example is low, and the TDS and COD of the recycled water are high. This indicates that the wastewater treatment and reuse apparatus and method provided in this disclosure in Example 1 can achieve higher evaporation efficiency, better energy consumption reduction, and better quality recycled water.

[0053] Example 2 This embodiment uses the same processing apparatus and processing method as in Embodiment 1, but differs from Embodiment 1 in that: The treatment involves high-salinity wastewater from a coal chemical plant. The wastewater has a pH of 7.1, a TDS of 32158 mg / L, and a COD of 269 mg / L. The wastewater retention time in the tank is 2 hours. The reflux ratio is 3:1, and the current density is 10 A / m³. 2 The measured evaporation efficiency was 1.76 kg / (m³). 2 h).

[0054] The treated recycled water (collection tank) had a TDS of 287 mg / L, a COD of 34 mg / L, and a conductivity of 389 μS / cm.

[0055] Example 3 This embodiment refers to the apparatus and method in Embodiment 1, but differs from Embodiment 1 in that: The photothermal conversion material layer of the photothermal conversion layer is a black carbon nanotube coating (obtained by conventional coating after uniform mixing of 15mg carbon nanotubes and 1mL chitosan solution). The thickness of the obtained photothermal conversion layer is 0.1mm. Based on the total weight of the photothermal conversion layer, the content of photothermal conversion material (carbon nanotubes) is 1.5% by weight. The rest of the process is the same as in Example 1.

[0056] The measured evaporation efficiency was 1.46 kg / (m³). 2 h). The treated recycled water (collection tank) had a TDS of 246 mg / L, a COD of 15 mg / L, and a conductivity of 320 μS / cm.

[0057] Comparing this embodiment with Embodiment 1, the carbon nanotube content in the photothermal conversion coating in Embodiment 1 is within the preferred range (2-8% by weight) provided in this disclosure. Using the device in Embodiment 1 for wastewater and reuse treatment results in higher evaporation efficiency and higher quality recycled water obtained in the collection tank.

[0058] Example 4 This embodiment refers to the apparatus and method in Embodiment 1, but differs from Embodiment 1 in that: The photothermal conversion material layer of the photothermal conversion layer is a black carbon nanotube coating (obtained by conventional coating after uniform mixing of 5mg carbon nanotubes and 1mL chitosan solution). The thickness of the obtained photothermal conversion layer is 0.1mm. Based on the total weight of the photothermal conversion layer, the content of photothermal conversion material (carbon nanotubes) is 0.5% by weight. The rest of the process is the same as in Example 1.

[0059] The measured evaporation efficiency was 1.35 kg / (m³). 2 h). The treated recycled water (collection tank) had a TDS of 238 mg / L, a COD of 11 mg / L, and a conductivity of 302 μS / cm.

[0060] Comparing this embodiment with Embodiment 3, it can be seen that the carbon nanotube content in the photothermal conversion coating in Embodiment 3 is within the optimized range (1~15% by weight) provided in this disclosure. Using the device in Embodiment 3 for wastewater and reuse treatment results in higher evaporation efficiency and higher quality recycled water obtained in the collection tank.

[0061] Example 5 This embodiment refers to the apparatus and method in Embodiment 1, but differs from Embodiment 1 in that: The wastewater retention time in the tank is 240 hours, the reflux ratio is 10:1, and the current density is 1 A / m³. 2 The remaining process is the same as in Example 1.

[0062] The measured evaporation efficiency was 1.47 kg / (m³). 2 h). The treated recycled water (collection tank) had a TDS of 248 mg / L, a COD of 153 mg / L, and a conductivity of 330 μS / cm.

[0063] Comparing this embodiment with Embodiment 1, Embodiment 1 uses the optimized conditions provided in this disclosure for wastewater treatment. In Embodiment 1, the evaporation efficiency is higher and the quality of the recycled water obtained in the collection tank is also higher.

[0064] The preferred embodiments of this disclosure have been described in detail above. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0065] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0066] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A wastewater treatment and reuse apparatus, characterized in that, The device includes a water tank, a cathode, a porous anode plate integrating photothermal conversion and electrocatalytic anode, a transparent condenser cover, and a water collection tank. The first main surface of the porous anode plate is provided with a photothermal conversion layer, and the second main surface of the porous anode plate is in contact with the water in the water tank. The cathode is disposed in the water. The condenser cover is disposed above the water tank to condense the water evaporated through the porous anode plate. The water collection tank is used to collect the water condensed by the condenser cover. The water collection tank includes a recycled water outlet.

2. The apparatus according to claim 1, characterized in that, The condenser shroud includes a first sidewall, a second sidewall, a third sidewall, and a fourth sidewall; the water tank includes a fifth sidewall, a sixth sidewall, a seventh sidewall, and an eighth sidewall; the first sidewall is correspondingly disposed above the fifth sidewall, the second sidewall is correspondingly disposed above the sixth sidewall, and the third sidewall is correspondingly disposed above the seventh sidewall; With the eighth side wall of the water tank as the boundary, the fourth side wall of the condenser shroud is located outside the eighth side wall of the water tank, and the bottom of the fourth side wall of the condenser shroud is connected to the top of the eighth side wall of the water tank through a base plate; preferably, the bottom of the fourth side wall of the condenser shroud and the top of the eighth side wall of the water tank are located on the same plane. Preferably, the top of the eighth side wall of the water tank is provided with a baffle, the baffle has a gap with the top of the condenser shroud, the baffle has a gap with the fourth side wall of the condenser shroud, and the baffle, the fourth side wall of the condenser shroud and the bottom plate form the water collection tank; the fourth side wall of the condenser shroud is provided with the recycled water outlet.

3. The apparatus according to claim 2, characterized in that, The fourth sidewall of the condenser shroud is disposed opposite to the third sidewall; the height of the fourth sidewall is lower than the height of the third sidewall, so that the top wall of the condenser shroud is inclined downward along the direction from the third sidewall to the fourth sidewall. Preferably, the inclination angle between the top wall and the horizontal direction is 5~80°, more preferably 15~60°.

4. The apparatus according to claim 1, characterized in that, The photothermal conversion layer is a black photothermal conversion coating; optionally, the photothermal conversion coating includes a photothermal conversion material, which is selected from one or more of polypyrrole, graphene, black chromium, and carbon nanotubes; preferably, carbon nanotubes; Optionally, the photothermal conversion coating further includes a binder selected from one or more of chitosan, water glass, and epoxy resin; preferably, the photothermal conversion coating includes carbon nanotubes and chitosan; more preferably, based on the total weight of the photothermal conversion coating, the content of carbon nanotubes is 1-15% by weight, preferably 2-8% by weight. More preferably, the thickness of the photothermal conversion layer is 0.001~2mm, more preferably 0.01~0.5mm.

5. The apparatus according to claim 1, characterized in that, The porous anode plate is made of one or more of the following materials: titanium suboxide, stainless steel, and graphite; preferably titanium suboxide.

6. The apparatus according to claim 1, characterized in that, The thickness of the porous anode plate is 0.1~5mm, preferably 0.5~2mm; the openings on the porous anode plate are through-holes; preferably, the aperture of the openings on the porous anode plate is 0.01~1mm, preferably 0.05~0.1mm.

7. The apparatus according to claim 1, characterized in that, The water tank is an open cuboid, and the ratio of the length to the width of the water tank is 0.5 to 10:1, preferably 1 to 3:1; the ratio of the length to the height of the water tank is 0.1 to 10:1, preferably 0.5 to 5:

1.

8. The apparatus according to claim 1, characterized in that, The distance between the cathode and the porous anode plate is 5~100mm, preferably 10~30mm; Optionally, the cathode is selected from one of graphite electrode, activated carbon fiber electrode and metal electrode; preferably, it is a graphite electrode.

9. A method for wastewater treatment and reuse using the apparatus described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Allow the wastewater to be treated to enter the water tank of the device; S2. Connect voltage to the porous anode plate and cathode respectively to perform electrocatalytic treatment on the wastewater to be treated in the water tank; expose the photothermal conversion layer of the porous anode plate to sunlight; S3. The water evaporated through the porous anode plate is condensed in the condenser hood, collected in the water collection tank, and then discharged through the recycled water outlet for reuse.

10. The method according to claim 9, characterized in that, The wastewater to be treated has a pH of 5-10, preferably 6-9; a TDS of 0.1-300000 mg / L, preferably 1-100000 mg / L; and a COD of 30-300000 mg / L, preferably 200-50000 mg / L.

11. The method according to claim 9, characterized in that, The current density between the porous anode plate and the cathode is 0.1~1000 A / m. 2 Preferably 1~500A / m 2 More preferably 2~50A / m 2 ; The residence time of the wastewater to be treated in the water tank is 0.1~240h, preferably 0.5~120h.

12. The method according to claim 9, characterized in that, The method also includes: At least a portion of the treated wastewater is returned to the water tank for further treatment; Preferably, the wastewater recirculation ratio is 0.1 to 20:1, more preferably 0.5 to 5:1.

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