Treatment method for removing CECs in tap water and small clean water boiler

Abstract

The invention discloses a treatment method for removing CECs in tap water and a small clean water boiler, purification treatment is carried out by jointly using three technologies of heating, ultraviolet light catalysis and electrocatalytic oxidation, the small clean water boiler comprises a box body, and a water tank is arranged in the box body; a purification module, a control module and a display module are arranged in the box body; the purification module comprises a heating assembly, a photocatalysis assembly and an electro-catalysis assembly; the photocatalysis assembly comprises an ultraviolet lamp and an ultraviolet lamp power plug; the electro-catalysis assembly comprises an anode TiO2-IrRu mesh electrode plate and a cathode titanium mesh electrode plate; the method provided by the invention realizes efficient removal of four types of CECs including pesticides, drugs and personal care products, disinfection by-products and endocrine interferon.

Description

Technical Field

[0001] The present application belongs to the technical field of tap water treatment, and in particular relates to a treatment method for removing CECs in tap water and a small water purifier. Background Art

[0002] Drinking water is the basis of human survival and development. With the development of my country's economy and the improvement of people's living standards, the safety of drinking water has received increasing attention. New contaminants in water (Contaminants of Emerging Concern, CECs) refer to chemical pollutants that are "newly identified or not previously confirmed", "not subject to regulations", and "pose potential or actual threats to human health and the ecological environment". Studies have shown that CECs in tap water and bottled water are mostly disinfection by-products (DBP), pharmaceuticals and personal care products (PPCP) and endocrine disrupting compounds (EDC). These pollutants can have a great negative impact on the ecology and human health, including damage to the endocrine system of humans and animals, and increase the risk of cancer.

[0003] The Chinese government attaches great importance to the treatment of new pollutants. The General Office of the State Council issued the "Action Plan for the Treatment of New Pollutants", which clearly defines the task goal of significantly enhancing the treatment capacity of new pollutants by 2025. However, traditional water treatment plants usually do not monitor CECs comprehensively, and often rely on occasional detection rather than continuous monitoring, which makes it impossible for the treatment process to remove these pollutants in a targeted manner. In addition, the treatment processes in water plants (such as coagulation, sedimentation, filtration and disinfection) have certain effects in removing turbidity, microorganisms and some organic pollutants, but the effect on removing CECs is relatively limited. CECs have different properties, and a single treatment process is difficult to be effective for all CECs. Many types of CECs have high hydrophilicity and are difficult to remove by physical adsorption or precipitation. In addition, the concentration of many CECs is extremely low (nanogram to microgram level), making it difficult for traditional treatment processes to effectively remove them. In addition, new toxic byproducts may be generated during the treatment of CECs in water plants, further affecting water quality safety. Summary of the invention

[0004] In view of the insufficient removal effect of CECs by water supply plants, tap water treatment at the user terminal can be used as a reasonable supplementary strategy. Based on this, the present invention provides a treatment method for removing CECs from tap water and a small water purifier, which achieves efficient removal of four major types of CECs including pesticides, medicines and personal care products, disinfection byproducts, and endocrine disruptors. The heating-photoelectric oxidation technology achieved an average degradation rate of 8 model pollutants of 88.58% and 83.63% respectively within 30 minutes under boiling and room temperature conditions.

[0005] To achieve the above object, the technical solution adopted by the present invention includes:

[0006] A method for removing CECs from tap water, combining heating, ultraviolet catalysis and electrocatalytic oxidation to purify the water to be treated, wherein the specific conditions include:

[0007] Heat to 25-100°C;

[0008] The intensity of ultraviolet light in ultraviolet photocatalysis is 2201~4566LUX;

[0009] The voltage in the electrocatalytic oxidation is 0 to 48 V.

[0010] Preferably, the temperature is heated to 100° C.; the intensity of the ultraviolet light in the ultraviolet photocatalysis is 4566 LUX; and the voltage in the electrocatalytic oxidation is 21 V.

[0011] A small water purifier for realizing the treatment method for removing CECs in tap water described in the present invention is provided with: a box body, a water tank and an electric control box are arranged in parallel inside the box body; a photocatalytic component, an electrocatalytic component and a heating component are arranged from top to bottom in the water tank; an electric control circuit is arranged in the electric control box for controlling the photocatalytic component, the electrocatalytic component and the heating component to work alternately or simultaneously.

[0012] Optionally, a water inlet pipe is arranged at the top of the side of the water tank, a water outlet is arranged at the middle of the front side of the water tank, and a drain outlet is arranged at the bottom of the side of the water tank.

[0013] Optionally, the photocatalytic component includes a first ultraviolet lamp, a second ultraviolet lamp and a third ultraviolet lamp arranged on the top of the water tank; the electrocatalytic component includes an electrode sheet arranged in the middle of the water tank, and the electrode sheet is composed of an anode electrode sheet and a cathode electrode sheet; the heating component includes a heating tube and a thermocouple arranged at the bottom of the water tank.

[0014] Optionally, the anode electrode sheet is a TiO2-IrRu mesh electrode sheet, and the cathode electrode sheet is a titanium mesh electrode sheet; two anode electrode sheets and three cathode electrode sheets are cross-mounted, and the spacing between adjacent electrode sheets is 45 mm.

[0015] Optionally, the electric control circuit includes: a leakage protector and a time relay are arranged behind the power cord; three lines are separated from the time relay, the first line is connected to the temperature controller, the second line is connected to the switching power supply, and the third line is connected to the AC contactor; the five-hole module and the socket are connected to the AC contactor to power the ultraviolet lamp, and a photocatalytic switch is arranged on the line between the time relay and the AC contactor to realize the control of the opening and closing of the ultraviolet lamp; a heating switch is also connected between the temperature controller and the time relay. After the heating switch is closed, the temperature controller, the thermocouple and the solid-state relay are turned on to heat The line is opened, the temperature controller receives the real-time temperature signal of the thermocouple and compares it with the preset target temperature. If the water temperature is lower than the set value, the temperature controller outputs a control signal, and the solid-state relay receives the signal to start the heating tube. When the water temperature reaches the set value, the temperature controller receives the thermocouple signal and outputs the control signal again, and the solid-state relay receives the signal to turn off the heating tube. The power cord is connected to the switching power supply to convert AC power into DC power, and then connected to the voltage regulator, and the voltage regulator is connected to the electrocatalytic component. At the same time, the voltage regulator and the time relay are controlled by the electrocatalytic switch to realize the control of the electrocatalytic time.

[0016] Optionally, in the electronic control circuit, an emergency stop switch and a main switch are also arranged in series between the time relay and the power line; the emergency stop switch is connected under normal conditions; and the main switch K5 is disconnected under normal conditions.

[0017] Optionally, a float valve is installed at the water inlet pipe of the water tank.

[0018] The beneficial effects of the present invention include:

[0019] (1) The present invention couples three water treatment functions, heating, ultraviolet catalysis, and electrocatalytic oxidation, in the purification module, and regulates the operation of the three functions through the control module and the display module. Efficient removal of four major categories of CECs, including pesticides, pharmaceuticals and personal care products, disinfection byproducts, and endocrine disruptors, is achieved. Under boiling and room temperature conditions, the heating-photoelectric oxidation technology achieves an average degradation rate of 8 model pollutants within 30 minutes of 88.58% and 83.63%, respectively;

[0020] (2) The energy consumption cost of treating one ton of water by the present invention is only 0.63 yuan per ton. -1 The operating energy consumption is much lower than that required by E-UV / Cl2, UV / H2O2, electro-Fenton and other processes. The present invention effectively utilizes the energy input during the heating process, improves water quality while reducing energy consumption, meets the requirements of sustainable development, has high economic value in terms of energy conservation and emission reduction, and is expected to become a practical solution for families and small communities to improve the safety of drinking water. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0022] Figure 1 This is a front view of the appearance of the small water purifier device of the present invention;

[0023] Figure 2 This is the internal structure diagram of the water tank;

[0024] Figure 3 It is the internal structure diagram of the electric control box;

[0025] Figure 4 It is the circuit diagram of the electric control box;

[0026] Figure 5 This is a graph showing the degradation effects of different pollutants on the small-scale water purifier equipment under different working conditions within 30 minutes in the embodiment;

[0027] Figure 6 It is a trend chart showing the energy consumption of small water heaters under different working conditions as the pollutant degradation effect changes;

[0028] Figure 7 This is a comparison chart of the energy consumption of small water purifier equipment under different working conditions to reduce the pollutant concentration by one order of magnitude.

[0029] The numbers in the figure represent:

[0030] 1-box, 11-water tank, 111-water inlet pipe, 112-water outlet, 113-drainage outlet, 114-photocatalytic component, 1141-first ultraviolet lamp, 1142-second ultraviolet lamp, 1143-third ultraviolet lamp, 115-float valve, 116-electrocatalytic component, 1161-anode electrode sheet, 1162-cathode electrode sheet, 117-heating component, 1171-thermocouple, 1172-heating tube;

[0031] 12-electric control box, 121-power cord, 122-temperature controller, 123-voltage regulating display screen, 124-switch, 125-time relay, 126-five-hole module, 127-leakage protector, 128-AC contactor, 129-solid-state relay, 1210-switching power supply, 1211-voltage regulator, 1212-socket, k1-photocatalytic switch, k2-electrocatalytic switch, k3-heating switch, k4-emergency stop switch, k5-main switch;

[0032] 13-Top cover. DETAILED DESCRIPTION

[0033] The present invention is described in detail below with reference to the accompanying drawings and specific implementation methods.

[0034] Boiling, as a very common drinking water treatment method in households, can effectively kill microorganisms in water and remove certain volatile organic compounds (such as chloroform). However, boiling has limited removal effects on non-volatile organic pollutants. These pollutants are generally highly stable and will not decompose or volatilize when heated to 100°C. Advanced oxidation techniques (AOPs), which are characterized by the production of active oxygen species with strong oxidizing ability (mostly hydroxyl radicals·OH), can oxidize large molecular weight, difficult-to-degrade organic matter into low-toxic or non-toxic small molecules. Hydroxyl radical·OH is one of the strongest oxidants, with an extremely high standard oxidation potential, E(·OH / H2O) = 2.80V. SHE , which is very effective in degrading highly toxic and persistent pollutants.

[0035] For other common pollutants in water (such as conventional organic matter, microorganisms and suspended solids, etc.), conventional water treatment methods or single light and electricity treatment technologies can usually achieve ideal removal effects, which is fundamentally different from the treatment requirements of CECs: For conventional pollutants (such as microorganisms, turbidity, common organic matter), these pollutants can be efficiently removed in water plants through coagulation, sedimentation, filtration and conventional disinfection processes (such as chlorination or ozone treatment). Traditional heating methods (such as boiling) can also effectively kill microorganisms and remove certain volatile organic compounds. The applicability of single photocatalysis is: for organic pollutants that can absorb ultraviolet light, ultraviolet photocatalysis alone can achieve a good degradation effect. For example, pesticide pollutants with high ultraviolet absorption coefficients can be degraded by photocatalysis, but this may not be applicable to CECs with complex structures. The applicability of single electrocatalysis is: for pollutants that can directly transfer electrons on the electrode surface (such as certain metal ions and simple organic matter), electrocatalysis can achieve efficient removal through simple electrolysis or electrochemical oxidation. However, due to the stable molecular structure and limited mass transfer of CECs, electrocatalysis alone often cannot achieve ideal degradation effects.

[0036] The present invention focuses on the photocatalytic oxidation and electrocatalytic oxidation technologies in AOPs. The main mechanism of ultraviolet light oxidation is to excite the photocatalyst by ultraviolet light irradiation, generate electron-hole pairs, and then trigger the generation of active oxygen species such as OH. Active oxygen species mainly composed of OH attack CECs molecules, causing them to break bonds and oxidize, and eventually degrade some CECs into harmless small molecules such as carbon dioxide and water. However, the recombination of photogenerated electron-hole pairs is one of the main limitations of the ultraviolet light oxidation process. Photogenerated electrons recombine with unused holes or react with adsorbed OH, resulting in reduced photocatalytic efficiency. The main mechanism of electrocatalytic oxidation is to generate highly active oxidants such as OH on the electrode surface and spread them in the solution to achieve the purpose of efficiently degrading CECs in water. However, the efficiency of electrocatalytic oxidation is limited by problems such as the mass transfer rate of pollutants, and the power consumption is high. In addition, during the treatment process, the electrodes may be contaminated, corroded or poisoned, affecting the treatment effect.

[0037] Coupling heating, UV photocatalysis and electrocatalytic oxidation to treat terminal drinking water can effectively solve the limitations of their individual applications, while enhancing the CECs removal efficiency of the overall system and improving the breadth and stability of water treatment. Coupling UV photocatalysis and electrocatalytic oxidation can further decompose non-volatile organic pollutants on the basis of heating. Through UV-assisted catalysis, the electrocatalytic process reduces the need for high voltage and reduces energy consumption. In addition, the auxiliary effect of photocatalysis can reduce electrode contamination and extend the service life of the electrode. At the same time, electrocatalysis can assist UV photocatalysis, reduce the recombination of photogenerated electron-hole pairs, and increase the generation of active oxygen species such as ·OH. However, since the diffusion coefficient of ·OH in water is very small (about 2.3×10 -5 cm 2 ·s -1 ), the residence time is very short (10 -9 ~10 -6 s). Therefore, the main place for the generation and oxidation of CECs is near the UV lamp and the anode. Therefore, the flow state of water and the change of the molecular movement speed will have a significant impact on the mixing degree and mass transfer of the solution in the system, and then affect the efficiency of OH degradation of CECs. When the temperature in the reaction system increases, the viscosity of the liquid decreases, the diffusion coefficient increases, and the transport capacity of the liquid increases. As the temperature increases, the movement of water molecules intensifies, the mixing rate of solutes in the system increases, and the collision probability of photons, active oxygen species and pollutant molecules in the system increases. Therefore, adding a heating function on the basis of photoelectric coupling technology can further improve the degradation efficiency of CECs molecules.

[0038] The combined use of heating, ultraviolet photocatalysis and electrocatalytic oxidation can fully utilize the advantages of the three technologies to achieve efficient removal of CECs. This multi-technical coupling can compensate for the limitations of a single technology and achieve deep treatment and broad-spectrum removal of pollutants. This multi-technical synergy can provide an efficient, economical and convenient solution for the deep purification of terminal drinking water, thereby improving the removal efficiency of CECs in drinking water and enhancing water quality safety.

[0039] The first aspect of the present invention provides a treatment method for removing CECs from tap water, which uses heating, ultraviolet catalysis and electrocatalytic oxidation to perform purification treatment, so that the heating-photoelectric coupling technology can achieve efficient pollutant degradation under low energy consumption conditions, including the following control processes: a process of enhancing the reaction efficiency of pollutants and active oxygen species, wherein the process of enhancing the reaction efficiency of pollutants and active oxygen species is achieved by heating to increase the water temperature, thereby reducing the viscosity of the liquid, increasing the generation rate of active oxygen species, and increasing the diffusion rate of pollutants and active oxygen species in water;

[0040] The process of improving the oxidation efficiency of ultraviolet photocatalysis is achieved by applying an external bias voltage during the electrocatalytic oxidation process to inhibit the recombination of photogenerated electrons and holes in the photocatalytic process; the process of improving the efficiency of electrocatalysis is achieved by oxidizing and removing organic pollutants on the electrode surface through the active oxygen species generated by the ultraviolet photocatalytic process, maintaining the clean state of the electrode, and reducing electrode pollution; the process of reducing the energy consumption of electrocatalysis is achieved by using ultraviolet photocatalysis to assist the electrocatalytic process and reduce the electric field strength requirement applied to the electrode during the electrocatalytic process.

[0041] In the present invention, CECs (new pollutants) are distinguished from other common pollutants in water (such as common organic matter, suspended matter, microorganisms, etc.), and their main characteristics are:

[0042] 1) Structural complexity: CECs usually include pesticides, pharmaceuticals and personal care products, disinfection by-products and endocrine disruptors. These pollutants have complex molecular structures and high chemical stability, making them difficult to remove through traditional water treatment methods (such as coagulation, filtration, and sedimentation).

[0043] 2) Widespread presence at low concentrations: CECs are usually present in water at extremely low concentrations (nanogram to microgram levels), but they still pose significant risks to the environment and human health. Due to their low concentrations, traditional physical and chemical adsorption methods are difficult to effectively capture and degrade them.

[0044] 3) Biodegradability: CECs have high biostability and are difficult to be degraded by microorganisms in conventional biotreatment processes. In addition, some CECs may have toxic effects on microbial communities, further reducing the efficiency of biotreatment.

[0045] Due to the complex characteristics of CECs, it is difficult for a single treatment technology to fully and effectively remove them. However, the coupling of heat, light and electricity can work together to achieve efficient pollutant degradation. The necessity and effectiveness of this multi-technology combination are reflected in the following aspects:

[0046] 1) Heating enhances the reaction environment: Heating not only increases the water temperature and reduces the viscosity of the liquid, but also accelerates the diffusion rate of pollutants and active oxygen species, significantly improving the mass transfer efficiency in the system. For CECs with high stability, this heating effect can enhance the generation and transfer of active oxygen species, thereby providing more favorable reaction conditions for subsequent photocatalytic and electrocatalytic processes.

[0047] 2) Photocatalysis for primary oxidation: UV light catalysis generates electron-hole pairs by exciting photocatalysts, generating highly oxidizing active oxygen species such as hydroxyl radicals (·OH), which attack the complex molecular structure of CECs and degrade them into smaller, low-toxic or non-toxic compounds. However, although photocatalysis has a broad spectrum of oxidative capacity, it is difficult to effectively degrade certain CECs that are highly stable or difficult to absorb UV light using photocatalysis alone.

[0048] 3) Electrocatalysis deepens the oxidation process: During the electrocatalytic process, strong oxidants are generated on the electrode surface, and the migration of photogenerated electrons is promoted through an external electric field, reducing the recombination of photogenerated electrons and holes, thereby increasing the generation rate of active oxygen species. This photoelectric synergy not only enhances the oxidation depth of pollutants, but also provides further oxidation pathways for CECs with complex structures and limited photocatalytic degradation effects. In addition, the introduction of photocatalysis can reduce the workload of electrocatalysis, reduce the voltage and electrical energy required for the electrocatalytic process, and thus significantly reduce the energy consumption of the entire system while further enhancing the overall treatment effect of the system.

[0049] Through the combined action of heat, light and electricity, the present invention achieves a significant synergistic effect. Heating creates a more favorable reaction environment for the photoelectric process. Photocatalysis can not only effectively carry out primary oxidation, but also reduce the energy consumption of electrocatalysis. Electrocatalysis ensures the thorough removal of pollutants by deepening oxidation and improving photocatalytic efficiency. Specific conditions include: heating to 25-100°C; the UV light intensity in UV photocatalysis is 2201-4566LUX; and the voltage in electrocatalytic oxidation is 0-48V. A more preferred scheme is: heating to 100°C; the UV light intensity in UV photocatalysis is 4566LUX; and the voltage in electrocatalytic oxidation is 21V.

[0050] The second aspect of the present invention uses the above-mentioned treatment method for removing CECs from tap water to design a small water purifier for removing CECs from tap water. Through the synergistic effect of the three functions of heating, ultraviolet light oxidation and electrocatalytic oxidation, the effective removal of CECs in water and the efficient purification of drinking water are achieved. The specific technical solution is:

[0051] Combination Figure 1-4 The small water purifier for removing CECs from tap water of the present invention is provided with: a housing 1, a water tank 11 and an electric control box 12 are arranged in parallel in the housing 1; a photocatalytic component 114, an electrocatalytic component 116 and a heating component 117 are arranged from top to bottom in the water tank 11; an electric control circuit is arranged in the electric control box 12 for controlling the photocatalytic component 114, the electrocatalytic component 116 and the heating component 117 to work alternately or simultaneously.

[0052] The heating component includes a heating tube and a thermocouple for heating tap water; the photocatalytic component includes an ultraviolet lamp and an ultraviolet lamp power plug for ultraviolet photocatalysis; the electrocatalytic component includes an anode TiO2-IrRu mesh electrode sheet and a cathode titanium mesh electrode sheet for electrocatalytic oxidation treatment;

[0053] The heating tube 1172 is arranged at the bottom of the water tank 11; the thermocouple 111 is located above the heating tube 1172 to monitor the water temperature in real time; the ultraviolet lamp is installed in a triangular shape on the top of the water tank, and the photocatalytic component 114 includes a first ultraviolet lamp tube 1141, a second ultraviolet lamp tube 1142 and a third ultraviolet lamp tube 1143 arranged on the top of the water tank 11; the electrocatalytic component 116 includes an electrode sheet arranged in the middle of the water tank, and the electrode sheet is composed of an anode electrode sheet 1161 and a cathode electrode sheet 1162, and the anode TiO2-IrRu mesh electrode sheet and the cathode titanium mesh electrode sheet are cross-mounted inside the water tank; the ultraviolet lamp adopts a 254nm fully submersible ultraviolet lamp; the electrode sheet spacing is 45mm, the cathode titanium mesh electrode sheet and the anode TiO2-IrRu mesh electrode sheet are cross-mounted, and a total of two anode electrode sheets and three cathode electrode sheets are installed;

[0054] Combination Figure 4The electric control circuit of the present invention includes: a leakage protector 127 is set behind the power line 121, and then to the time relay 125. There are three paths from the time relay 125, one path is connected to the temperature controller 122, one path is connected to the switch power supply 1210, and one path is connected to the AC contactor 128. The emergency stop switch k4 is connected under normal conditions. When the emergency stop button is pressed, it changes from the connected state to the disconnected state, so the current of the entire path is cut off. The main switch K5 is disconnected under normal conditions. When it is closed, the entire circuit is connected. In other words, the total current is controlled by K4 and K5. The five-hole module 126 and the socket 1212 are connected to the ultraviolet lamp power plug to supply power to the ultraviolet lamp 114, and the opening and closing control is realized through the photocatalytic switch k1 connected to the time relay 125 and the AC contactor 128; after the heating switch k3 is closed, the temperature controller 122, the heating component 117 and the solid-state relay 129 are connected, the heating circuit is opened, the temperature controller 122 receives the real-time temperature signal of the thermocouple 1171, and compares it with the preset target temperature. If the water temperature is lower than the set value, the temperature controller 122 outputs a control signal, and the solid-state relay 129 receives the signal to start the heating tube 1172. When the water temperature reaches the set value, the temperature controller 122 receives the thermocouple 1171 signal and outputs the control signal again, and the solid-state relay 1 29 receives the signal to turn off the heating tube 1172; the solid-state relay 129 receives the control signal of the temperature controller 122 to control the on and off of the heating tube 1172; the switching power supply 1210 is connected to the voltage regulator 1211, the switching power supply 1210 receives 220V AC power and outputs 48V DC power to the voltage regulator 1211, so that it can adjust the voltage between 0-48V; the voltage regulator 1211 is connected to the electrode sheet, and accurately adjusts the output voltage between 0-48V according to the preset value. At the same time, the voltage regulator 1211 and the time relay 125 are controlled to be on and off through the electrocatalytic switch k2, so as to realize the control of the electrocatalytic time. The voltage regulator 1211 is connected to the voltage regulating display screen 123, and the voltage regulating display screen 123 displays the real-time voltage value.

[0055] The temperature controller display screen has the functions of setting the preset temperature value and displaying the real-time water temperature in the water tank. According to the preset value, the temperature controller outputs a control signal to adjust the water temperature and receives feedback signals from the thermocouple to ensure the equipment's precise control of the temperature; the voltage regulator display screen presets the voltage value through the knob. According to the preset value, the voltage regulator accurately adjusts the input voltage on the electrode sheet and receives feedback signals, and displays the real-time working voltage, current and power data of the electrode sheet, which is convenient for monitoring the electrocatalytic oxidation process. The time relay controls the working time of the equipment. When the preset working time is reached, it outputs a control signal, and the AC contactor receives the signal to disconnect the photocatalytic circuit; the leakage protector is connected to the front end of the power supply line to detect leakage current and control the circuit on and off to protect the equipment's operating circuit;

[0056] A water inlet pipe 111 is arranged at the top of the side of the water tank 11, a water outlet 112 is arranged at the middle of the front side of the water tank 11, and a drain outlet 113 is arranged at the bottom of the side of the water tank 11; specifically, for example, the size of the water heater is 550mm×250mm×530mm. Its shell is made of 201 stainless steel, the surface is sprayed with plastic, and the color is sand surface black. Piers are installed at the four corners of the base of the water heater. The water tank 11 is installed on the left, and the electric control box 12 is installed on the right. A float valve 115 is installed at the water inlet pipe 111 of the water tank 11 to control the water level.

[0057] Embodiment 1:

[0058] Combination Figures 1 to 4 As shown, this embodiment provides a small water purifier for removing CECs in tap water, wherein a housing 1 is provided, wherein a water tank 11 and an electric control box 12 are arranged in parallel in the housing 1; a photocatalytic component 114, an electrocatalytic component 116 and a heating component 117 are arranged from top to bottom in the water tank 11; an electric control circuit is arranged in the electric control box 12 for controlling the photocatalytic component 114, the electrocatalytic component 116 and the heating component 117 to work alternately or simultaneously. The photocatalytic component 114 includes a first ultraviolet lamp tube 1141, a second ultraviolet lamp tube 1142 and a third ultraviolet lamp tube 1143 arranged on the top of the water tank 11; the electrocatalytic component 116 includes an electrode sheet arranged in the middle of the water tank, and the electrode sheet is composed of an anode electrode sheet 1161 and a cathode electrode sheet 1162; a heating tube 1172 is arranged at the bottom of the water tank 11; a thermocouple 1171 is located above the heating tube 1172 to monitor the water temperature in real time; a water inlet pipe 111 is arranged at the top of the side of the water tank 11, a water outlet 112 is arranged in the middle of the front side of the water tank 11, and a drain outlet 113 is arranged at the bottom of the side of the water tank 11. A float valve 115 is installed at the water inlet pipe 111 of the water tank 11 to control the water level;

[0059] A water tank 11 is arranged inside the box 1. The water tank is made of 201 stainless steel and has polytetrafluoroethylene (PTFE) sprayed on the surface as an insulating coating. A heating tube 1172 is arranged at the bottom of the water tank 11. A thermocouple 1171 is arranged above the heating tube 1172 to measure the water temperature in real time and generate a corresponding electrical signal, which is transmitted to the temperature controller 122. The temperature controller 122 receives the electrical signal and compares it with the set target temperature. When the water temperature is lower than the set value by more than 2°C, the temperature controller 122 will output a control signal. After the solid-state relay 129 receives the signal, it starts the heating tube 1172. When the water temperature reaches the set value, the temperature controller 122 turns off the control signal to the solid-state relay 129, thereby disconnecting the circuit of the heating tube 1172. When the water temperature drops to more than 2°C below the set value again, the thermocouple 1171 sends a signal again, and the temperature controller 122 restarts the heating tube 1172. Five mesh electrode sheets are arranged above the thermocouple 1171, which are cathode, anode, cathode, anode and cathode. TiO2-IrRu electrode mesh is selected as anode and titanium mesh is selected as cathode. Because the mesh electrode has a larger surface area and more active points, it helps to increase the contact area between the electrode and the CECs molecules in water, thereby improving the reaction efficiency; TiO2-IrRu anode has excellent catalytic performance and corrosion resistance, can achieve efficient degradation at a lower voltage, and prolong the service life of the electrode; pure titanium cathode has good conductivity and corrosion resistance, and can stably support the reaction. The electrode spacing is 45mm. The top of the electrode sheet is fixed on the stainless steel plate 261. The voltage control process on the electrode sheet is as follows: the equipment is connected to a 220V AC power supply through the power cord connection port, and the 220V AC power is converted into 48V DC power through the voltage regulator 1211, providing the system with a low-voltage DC power supply suitable for electrocatalytic oxidation. The 48V DC power after power conversion is introduced into the voltage regulator 1211. The voltage regulator 1211 is used to accurately adjust the output voltage, and can apply voltage to the electrode sheet according to the preset value within the range of 0 to 48V. The regulated DC voltage is transmitted to the electrode sheet to drive the electrocatalytic oxidation reaction. The voltage applied to the electrode sheet directly affects the intensity and efficiency of the reaction. By adjusting the applied voltage, the system can optimize the oxidation process of pollutants. The system is equipped with a voltage and current monitoring module to monitor the voltage and current parameters on the electrode sheet in real time and display them on the voltage regulating display screen 123.

[0060] The first ultraviolet lamp tube 1141, the second ultraviolet lamp tube 1142 and the third ultraviolet lamp tube 1143 are arranged around the electrode sheet, and the top of the ultraviolet lamp tube is fixed on the top plate of the box body 1, which is used for photocatalytic oxidation treatment of drinking water. The first ultraviolet lamp tube 1141, the second ultraviolet lamp tube 1142 and the third ultraviolet lamp tube 1143 are arranged in a triangle to ensure that the water in the water tank is irradiated with ultraviolet rays more evenly and reduce dead angles. A float valve 115 is arranged at the end of the water inlet pipe 19 to control the water level in the water tank. The top plate surface of the box body 1 is sprayed with polytetrafluoroethylene (PTFE) as an insulating coating.

[0061] Embodiment 2:

[0062] This embodiment uses the small water purifier with integrated heating and water quality improvement functions of Embodiment 1 to conduct simulation tests in the laboratory. The water sample in the experiment uses tap water from Xi'an as raw water. From the four types of CECs, namely pesticides, antibiotics, disinfection by-products, and endocrine disruptors, atrazine, dimethoate, ibuprofen, sulfamethoxazole, carbamazepine, trichloroacetic acid, 3,5-dichlorosalicylic acid, and bisphenol A, a total of eight pollutants were selected as model pollutants. The initial mass concentration of the model pollutant was 100 μg·L -1 . With the water temperature of 100℃ as the initial condition, the water samples configured with each model pollutant were subjected to a degradation process under four working conditions: single heating, heating-electrocatalytic oxidation, heating-ultraviolet light oxidation, and heating-photoelectrooxidation (boiling). In addition, with the water temperature of 25℃ as the initial condition, heating-photoelectrooxidation (normal temperature) degradation was carried out again. The water sample reacted in the equipment for 30 minutes, during which samples were taken every 5 minutes. After the water sample was filtered through a 0.22μm filter membrane, a liquid chromatography-mass spectrometer (WatersUPLC-TQD) was used to detect the concentration changes of the eight model pollutants during the degradation process. The electrocatalytic voltage was constant at 21V.

[0063] Table 1 Number of lamps and corresponding illuminance

[0064]

[0065] This example studies the degradation effect of different types of CECs by the combined use of three technologies, heating, photocatalysis, and electrocatalysis under different working conditions, and the influence of reaction temperature on the degradation effect of CECs.

[0066] Table 2 Water quality parameters of tap water used in the experiment

[0067]

[0068] Combination Figure 5The experimental results show that heating alone has a poor degradation effect on the eight model pollutants. After boiling for 30 minutes, the degradation rate of half of the model pollutants was less than 10%, and the degradation rate of most of the model pollutants was less than 20%. The degradation rate of 3,5-dichlorosalicylic acid, which had the best degradation effect, was only 21.07%, proving that traditional heating alone cannot effectively remove CECs.

[0069] Combination Figure 5 , the experimental results show that the removal effects of heating-UV oxidation on the eight model pollutants showed great differences. The degradation rate of heating-UV oxidation on four pollutants, atrazine, sulfamethoxazole, dimethoate, and trichloroacetic acid, reached more than 80%. At the same time, its degradation rate for ibuprofen was only 12.26%. The reason for the better removal effect of the four model pollutants may be the strong ability to absorb ultraviolet light. For example, dimethoate has a high ultraviolet absorption coefficient, so its concentration is significantly reduced after irradiation with ultraviolet light. In contrast, ibuprofen may have a weaker ability to absorb ultraviolet light, resulting in its low degradation rate.

[0070] Combination Figure 5 The experimental results show that the removal effects of heating-electrocatalytic oxidation on the eight model pollutants also show great differences. In contrast to heating-ultraviolet light oxidation, the degradation rates of ibuprofen and 3,5-dichlorosalicylic acid by heating-electrocatalytic oxidation reached 92.57% and 90.94%, respectively, and the degradation rates of dimethoate and bisphenol A were all above 85%, with very good degradation effects. However, the degradation rates of sulfamethoxazole and carbamazepine were less than 40%, and the degradation rate of atrazine was only 15.78%, with poor degradation effects. In the heating-electrochemical oxidation process, pollutants are mainly degraded by direct transfer of electrons. The low degradation rate of atrazine may be due to the limited mass transfer on the anode surface. That is, although the molecules reach the electrode surface, they cannot effectively exchange electrons with the electrode. This may be because the molecular structure of pollutants such as atrazine is not conducive to adding electrons, or the catalytic active sites on the surface of the anode TiO2-IrRu mesh electrode sheet are not suitable for this type of chemical reaction, which makes it difficult to be oxidized, resulting in a low degradation rate of them by heating-electrochemical oxidation alone.

[0071] Combination Figure 5, the experimental results show that heating-photoelectrooxidation (boiling) shows a good degradation effect on most model pollutants. Among the 8 model pollutants, carbamazepine has the lowest degradation rate, which is 58.80%. In addition, the degradation rates of the other 7 model pollutants are all above 90%. And the degradation rates of all model pollutants are higher than those of heating-electrocatalytic oxidation or heating-photocatalytic oxidation alone. The reason for this is the synergistic and complementary effect between photoelectricity. There are many degradation pathways in the photoelectrooxidation system, including direct photolysis of ultraviolet rays, direct oxidation of the anode, and free radical oxidation. In addition, the TiO2-IrRu anode material in the system provides a path for photocatalytic oxidation to degrade pollutants. At the same time, the applied external bias also reduces the recombination of photogenerated electron holes in the system, thereby improving the degradation efficiency. An important significance of heating-photoelectrocatalysis is that it can not only enhance the removal efficiency of CECs, but also expand the treatment range, so that pollutants that are not highly reactive to a single method can also be effectively degraded. For example, the degradation rate of ibuprofen under heating-UV light oxidation conditions was only 12.26%, and the degradation rate of sulfamethoxazole under heating-electrocatalytic oxidation conditions was only 34.58%. However, under heating-photoelectric oxidation conditions, the degradation rates of ibuprofen and sulfamethoxazole reached 94.56% and 96.20%, respectively, and the degradation effect was significantly improved.

[0072] Combination Figure 5 The experimental results show that both heating-photoelectrooxidation (normal temperature) and heating-photoelectrooxidation (boiling) effectively promote the degradation of 8 model pollutants, and show a wider treatment range than heating-electrocatalytic oxidation and heating-ultraviolet photocatalysis alone. However, under the condition of heating-photoelectrooxidation (normal temperature), the degradation efficiency of most model pollutants is lower than that under the condition of heating-photoelectrooxidation (boiling). For example, the degradation efficiency of dimethoate under the condition of heating-photoelectrooxidation (boiling) reached 90.40%, while the degradation efficiency under the condition of heating-photoelectrooxidation (normal temperature) was 80.07%. The reason may be that the generation rate of ·OH in the reaction system at high water temperature is higher than that at low water temperature. When water is close to boiling, water molecules absorb a lot of energy, the intermolecular forces weaken, hydrogen bonds begin to break, molecular motion accelerates, and molecular collisions increase. Under the combined effect of these factors, water molecules are more likely to undergo homolysis and ionization, thereby increasing the generation rate of ·OH. In addition, as the temperature increases, the viscosity of the liquid in the reaction system gradually decreases, the particle diffusion capacity increases, and the mass transfer rate of CECs molecules and the generated ·OH in water increases, thereby increasing the probability of collision between molecules and making the degradation reaction easier to occur. Therefore, a higher reaction temperature can more effectively promote the degradation of CECs.

[0073] The small water purifier of the present invention, which integrates heating and water quality improvement functions based on heating-photoelectric oxidation technology, can effectively degrade CECs, and is expected to become a practical solution for improving the safety of drinking water for families and small communities.

[0074] Embodiment 3:

[0075] This embodiment adopts the experimental data of embodiment 2 to study the energy consumption of the small water purifier equipment of the present invention under heating-ultraviolet light oxidation, heating-electrocatalytic oxidation, and heating-photoelectric oxidation (boiling) conditions as the pollutant degradation effect changes.

[0076] Energy consumption is an important indicator for evaluating the feasibility of a process in practical application, and determines the economic and application prospects of the process. The energy consumption of the equipment for removing CECs mainly comes from the electrocatalytic oxidation and photocatalytic oxidation processes. Use equations (1) to (3) to calculate the energy consumption of treating 1m2 of CECs under the conditions of heating-ultraviolet oxidation (H-UV), heating-electrocatalytic oxidation (HE) and heating-photoelectrocatalytic oxidation (boiling, H-UV-E). 3 Energy consumption of tap water. Energy consumption changes with the degradation process of pollutants. Figure 6 .

[0077]

[0078] Where: E is the energy consumption required for the process, kWh·m -3 ; P is the power of the ultraviolet lamp, W; t is the treatment time, min; V is the solution volume, L; I is the total current of the electrode plate, A; U is the voltage applied to the electrode plate, V.

[0079] The experimental results show that although heating-electrocatalytic oxidation can remove ibuprofen, dimethoate, and 3,5-dichlorosalicylic acid with relatively low energy consumption, the energy consumption required to remove atrazine and sulfamethoxazole is too high. On the other hand, although heating-ultraviolet light oxidation can degrade trichloroacetic acid and sulfamethoxazole with lower energy consumption, the energy consumption for degrading ibuprofen and 3,5-dichlorosalicylic acid is too high. Although heating-photoelectrocatalytic oxidation (boiling) consumes more energy during the degradation process, the degradation rate of model pollutants is higher than that of heating-electrocatalytic oxidation or heating-photocatalytic oxidation alone.

[0080] In order to more accurately and intuitively reflect the energy consumption required for the degradation of the model pollutants, equations (4) to (6) are used to calculate the energy consumption of 1 m 3 Energy consumption for reducing pollutant concentration in water by one order of magnitude. Energy consumption comparison see Figure 7 .

[0081]

[0082] Where: C0 and C t are the pollutant mass concentrations at time 0 and time t, μg·L -1 .

[0083] The experimental results show that for pollutants such as dimethoate, trichloroacetic acid, and bisphenol A, the energy consumption required for heating-photoelectrooxidation is slightly higher than that of heating-electrocatalytic oxidation or heating-photocatalytic oxidation alone. However, when degrading atrazine and sulfamethoxazole, the energy consumption of heating-photoelectrooxidation is much lower than that of heating-electrocatalytic oxidation. At the same time, when degrading ibuprofen and 3,5-dichlorosalicylic acid, the energy consumption of heating-photoelectrooxidation is much lower than that of heating-ultraviolet light oxidation. This reflects the wider treatment range of heating-photoelectrooxidation technology. For this type of pollutant, heating-photoelectrooxidation technology can degrade it with relatively less energy consumption (with Figure 7 ).

[0084] In general, although heating-photoelectric oxidation consumes more energy than single heating-electrocatalytic oxidation or heating-ultraviolet light oxidation for some pollutants, its higher treatment efficiency and wider application range can reduce its overall treatment energy consumption in long-term operation, especially in the treatment of difficult-to-degrade pollutants.

[0085] In order to explore the feasibility of heating-photoelectric oxidation technology to remove CECs in practical applications, this example also studies and compares the effects of heating-photoelectric oxidation technology with other technologies such as E-UV / Cl2, UV / H2O2, and electro-Fenton to remove CECs. And according to the energy consumption of treating 1 ton of water by different processes, the average electricity price of Xi'an is 0.49 yuan / (kWh) to roughly estimate the water treatment costs of different processes.

[0086] Table 3 Comparison of energy consumption of different processes

[0087]

[0088] The data in Table 3 show that the pollutant degradation rates of heating-electrocatalytic oxidation and heating-ultraviolet light oxidation alone are lower than those of other processes, and their application range is narrow. However, the heating-photoelectric oxidation technology only requires 30 minutes of processing time to degrade nearly 90% of pollutants while boiling water. At the same time, in terms of energy consumption, the energy consumption of the heating-photoelectric oxidation technology is much lower than that of the electrocoagulation, Fenton, and electro-Fenton processes. In addition, the heating-photoelectric oxidation technology does not require the addition of chemical reagents, reducing the risk of secondary pollution. Therefore, the heating-photoelectric oxidation technology can become a powerful competitive method for eliminating trace CECs in drinking water treatment.

[0089] The small water purifier based on the photoelectric system of the present invention, which integrates heating and water quality improvement functions, has low energy consumption under three working conditions. Especially under the heating-photoelectric oxidation (boiling) working condition, the equipment only needs 30 minutes of processing time to degrade nearly 90% of pollutants, and the energy consumption cost per ton of water treated is only 0.63 yuan per ton. -1 The small water purifier of the present invention not only simplifies the purification process, but also effectively utilizes the energy input during the heating process, thereby improving water quality while reducing energy consumption, meeting the requirements of sustainable development, and having high economic value in terms of energy conservation and emission reduction.

[0090] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A method for removing CECs from tap water, characterized in that: The water to be treated is purified by combining heating, UV catalysis and electrocatalytic oxidation, under the following conditions: Heat to 25-100°C; The intensity of ultraviolet light in ultraviolet photocatalysis is 2201~4566LUX; The voltage in the electrocatalytic oxidation is 0 to 48 V.

2. The method for removing CECs from tap water according to claim 1, characterized in that: Heating to 100°C; the UV light intensity in the UV photocatalysis was 4566LUX; and the voltage in the electrocatalytic oxidation was 21V.

3. A small water purifier for implementing the method for removing CECs from tap water according to claim 1 or 2, characterized in that: set up: A box body (1), wherein a water tank (11) and an electric control box (12) are arranged in parallel in the box body (1); A photocatalytic component (114), an electrocatalytic component (116) and a heating component (117) are arranged in the water tank (11) from top to bottom; An electric control circuit is arranged in the electric control box (12) for controlling the photocatalytic component (114), the electrocatalytic component (116) and the heating component (117) to work alternately or simultaneously.

4. The small water heater according to claim 3, characterized in that: A water inlet pipe (111) is arranged at the top of the side of the water tank (11), a water outlet (112) is arranged at the middle of the front side of the water tank (11), and a water drain outlet (113) is arranged at the bottom of the side of the water tank (11).

5. The small water heater according to claim 3 or 4, characterized in that: The photocatalytic component (114) comprises a first ultraviolet lamp tube (1141), a second ultraviolet lamp tube (1142) and a third ultraviolet lamp tube (1143) which are arranged on the top of the water tank (11); The electrocatalytic component (116) comprises an electrode sheet arranged in the middle of the water tank, and the electrode sheet is composed of an anode electrode sheet (1161) and a cathode electrode sheet (1162); The heating component (117) comprises a heating tube (1172) and a thermocouple (1171) arranged at the lower part of the water tank (11).

6. The small water heater according to claim 5, characterized in that: The anode electrode sheet (1161) is a TiO2-IrRu mesh electrode sheet, and the cathode electrode sheet (1162) is a titanium mesh electrode sheet; Two anode electrode sheets (1161) and three cathode electrode sheets (1162) are cross-mounted, and the spacing between adjacent electrode sheets is 45 mm.

7. The small water heater according to claim 3 or 4, characterized in that: The electric control circuit comprises: a leakage protector (127) and a time relay (125) are arranged behind the power line (121); Three lines are separated from the time relay (125), the first line is connected to the temperature controller (122), the second line is connected to the switching power supply (1210), and the third line is connected to the AC contactor (128); The five-hole module (126) and the socket (1212) are connected to the AC contactor (128) to supply power to the photocatalytic component (114); a photocatalytic switch (k1) is provided on the line between the time relay (125) and the AC contactor (128) to control the opening and closing of the photocatalytic component (114); A heating switch (k3) is also connected between the temperature controller (122) and the time relay (125), and a thermocouple (1171) and a solid-state relay (129) are connected to the temperature controller (122). The temperature controller (122) receives a real-time temperature signal from the thermocouple (1171) and compares it with a preset target temperature. If the water temperature is lower than the set value, the temperature controller (122) outputs a control signal, and the solid-state relay (129) receives the signal to start the heating tube (1172); when the water temperature reaches the set value, the temperature controller (122) receives the thermocouple (1171) signal and outputs a control signal again, and the solid-state relay (129) receives the signal to turn off the heating tube (1172); The power line (121) is connected to the switching power supply (1210) to convert the alternating current into direct current, and then connected to the voltage regulator (1211), and the voltage regulator (1211) is connected to the electrocatalytic component (116). At the same time, the voltage regulator (1211) and the time relay (125) are controlled to be on and off through the electrocatalytic switch (k2) to achieve control of the electrocatalytic time.

8. The small water heater according to claim 7, characterized in that: In the electric control circuit, an emergency stop switch (k4) and a main switch (k5) are also arranged in series between the time relay (125) and the power line (121); Emergency stop switch (k4), connected under normal conditions; The main switch (k5) is normally disconnected.

9. The small water heater according to claim 3 or 4, characterized in that: A float valve (115) is installed at the water inlet pipe (111) of the water tank (11).

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