A wastewater treatment system based on photo-Fenton reaction and PV-TEG

Abstract

This invention discloses a wastewater treatment system based on photo-Fenton reaction and PV-TEG, including a wastewater channel, a photo-Fenton wastewater treatment pipeline, and a storage tank. The photo-Fenton wastewater treatment pipeline is arranged on the front of the photovoltaic module, and its top is made of low-iron glass with high solar spectral transmittance. The wastewater channel is arranged on the back of the photovoltaic module and between the cold end of the thermoelectric module. The photo-Fenton wastewater treatment pipeline and the wastewater channel are connected, and a circulation loop is established between the photo-Fenton wastewater treatment pipeline and the storage tank. During system startup, a certain proportion of Fenton catalyst is added to the wastewater channel. The wastewater to be treated absorbs heat from the photovoltaic module and the thermoelectric module through the wastewater channel before entering the photo-Fenton wastewater treatment pipeline for photo-Fenton wastewater treatment. This invention can achieve higher power output while solving the problem of industrial wastewater treatment in factories, further improving the full-spectrum utilization capability of solar energy.

Description

Technical Field

[0001] This invention relates to wastewater treatment systems, and more specifically to a wastewater treatment system based on photo-Fenton reaction and PV-TEG. Background Technology

[0002] Photovoltaic (PV) energy is a clean and renewable energy source that converts solar radiation into electricity using solar photovoltaic cells. However, due to the limitations of semiconductor materials, only a portion of the energy in the solar spectrum can be effectively converted into electricity. In the development of photovoltaic technology, the utilization of the entire solar spectrum has received widespread attention, aiming to maximize the use of various wavelengths in the solar spectrum and improve the energy conversion efficiency of photovoltaic systems. To more effectively utilize the full spectrum of solar energy, many researchers have combined thermoelectric power generation technology with photovoltaic power generation technology. They have arranged semiconductor thermoelectric power generation devices on the back of photovoltaic cells, achieving a high degree of full-spectrum utilization of solar energy. However, because the operating temperature characteristics of photovoltaic cells and thermoelectric devices are diametrically opposed, the presence of thermoelectric devices severely affects the heat conduction of photovoltaic cells, leading to performance degradation in this series-connected photovoltaic-thermal power generation device and failing to achieve optimal synergistic power generation.

[0003] The Fenton reaction is a highly oxidizing reaction based on hydroxyl radicals (OH·), which involves reacting hydrogen peroxide (H₂O₂) with iron ions (Fe²⁺). 2+ or Fe 3+ The combination of these two processes generates highly oxidizing OH· free radicals in water to degrade organic pollutants. Photocatalysis utilizes visible or ultraviolet light to irradiate catalysts, such as titanium dioxide (TiO2) or iron oxides, to increase the oxidation reaction rate, which can improve water treatment efficiency. The photo-Fenton reaction combines the Fenton reaction and photocatalysis, where iron ions act as a catalyst, H2O2 provides the oxidant, and light promotes the reaction. This method has a highly efficient pollutant removal capacity and is suitable for degrading various harmful substances in organic wastewater. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to combine the photo-Fenton reaction and the PV-TEG full-spectrum solar energy utilization system to provide a wastewater treatment system based on the photo-Fenton reaction and PV-TEG, which can achieve higher power output, solve the problem of industrial wastewater treatment in factories, and further improve the full-spectrum utilization capability of solar energy.

[0005] Technical Solution: The wastewater treatment system based on photo-Fenton reaction and PV-TEG described in this invention includes a wastewater purification and circulation system, a photovoltaic module, and a thermoelectric module. The wastewater purification and circulation system includes a wastewater channel, a photo-Fenton wastewater treatment pipeline, and a water storage tank. One end of the wastewater channel is equipped with an inlet valve for introducing wastewater to be treated, and the other end is connected to one end of the photo-Fenton wastewater treatment pipeline via a pipeline. A circulation loop including a circulating water pump is established between the other end of the photo-Fenton wastewater treatment pipeline and the water storage tank. An outlet valve is installed on the water storage tank.

[0006] The wastewater treatment pipeline of the photo-Fenton method is arranged on the front of the photovoltaic module. The top of the wastewater treatment pipeline of the photo-Fenton method is made of low iron glass with high solar spectrum transmittance. The wastewater flow channel is arranged between the back of the photovoltaic module and the cold end of the thermoelectric module. The surface of the thermoelectric module is covered with a light-absorbing thin layer material, and an optical concentrator is installed at the bottom of the thermoelectric module.

[0007] In the initial stage of system startup, a certain proportion of Fenton catalyst is added to the sewage channel. Sunlight shines through low-iron glass into the photo-Fenton sewage treatment pipeline. Ultraviolet light, in conjunction with the Fenton catalyst, treats and degrades organic matter. The energy of the visible light portion of the solar spectrum is absorbed by the photovoltaic module through the water to generate electricity. The remaining unused energy is collected through the sewage in the sewage channel and transferred to the photo-Fenton sewage treatment pipeline. The thermoelectric module generates a heat transfer temperature difference at its hot and cold ends and generates electricity. The remaining energy is also collected through the sewage in the sewage channel and transferred to the photo-Fenton sewage treatment pipeline.

[0008] Furthermore, the wastewater treatment system based on photo-Fenton reaction and PV-TEG also includes a photovoltaic electrochemical treatment system. This system comprises positive and negative electrode plates installed in a storage tank. These plates are powered by electricity generated by the photovoltaic module, and excess electricity is stored in a battery via an MPPT unit and conversion and transmission device. Electricity generated by the thermoelectric module can also be stored in the battery. This technical solution utilizes solar-converted electricity for wastewater electrolysis, effectively combining photovoltaic power generation and wastewater treatment.

[0009] Furthermore, the wastewater treatment system based on photo-Fenton reaction and PV-TEG also includes a heat collection system, which includes a hot water storage tank. A heat exchange circulation loop, including a heat exchange circulation pump, is established between the hot water storage tank and the water storage pool to transfer heat to the hot water storage tank when the temperature in the water storage pool reaches a certain value.

[0010] This technical solution can achieve on-demand heat transfer as needed. When the water temperature in the wastewater purification and circulation system rises to a certain level, the heat is transferred to the hot water storage tank of the heat collection system, thus compensating for the heat loss in the heat collection system.

[0011] Furthermore, the hot water storage tank is connected to one end of the sewage channel, and the water in the hot water storage tank returns to the Guangfenton process sewage treatment pipeline for purification treatment via the sewage channel.

[0012] Furthermore, the hot water storage tank is equipped with a heat exchange coil, and the hot water storage tank supplies heat to the outside through a heat extraction circulation loop including the heat exchange coil and the heat extraction circulation pump, realizing the integration of power generation, heat collection, heating and water purification into one system.

[0013] Furthermore, each circulation loop is equipped with control valves for controlling the on / off state and regulating the flow rate.

[0014] Furthermore, the photovoltaic wastewater treatment pipeline is surrounded by aluminum on all sides, low-iron glass on top, and the outer glass of the photovoltaic module.

[0015] Furthermore, the optical concentrator has a concave structure and is rotatably mounted on the support. Adjusting the tilt angle of the optical concentrator can adapt to the incident angle of sunlight from various directions.

[0016] Furthermore, the light-absorbing thin-layer material has the ability to absorb the entire solar spectrum.

[0017] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0018] (1) By arranging photovoltaic modules (i.e., solar photovoltaic cells) and thermoelectric modules (i.e., solar photovoltaic thermoelectric devices) on both sides of the sewage flow channel, heat transfer is optimized. Specifically, the photovoltaic modules can quickly transfer heat to the sewage, effectively preventing heat accumulation and ensuring that they operate within a reasonable temperature range. At the same time, the thermoelectric modules can obtain more heat flow energy, increasing the heat transfer temperature difference between the hot and cold ends, thereby increasing the output power. In addition, the heat absorbed by the sewage can also play a catalytic role in the photo-Fenton reaction water treatment process. This design cleverly avoids the performance degradation problem of traditional series photovoltaic-thermal power devices, realizes the synergistic operation of two solar power generation devices with opposite temperature characteristics, and makes full use of waste heat resources.

[0019] (2) The Fenton wastewater treatment pipe located above the photovoltaic module can utilize the ultraviolet energy in the solar spectrum to sterilize and purify the water. At the same time, the water can also absorb the infrared energy in the solar spectrum, reducing the impact of the photovoltaic module's temperature rise on performance. Introducing ultraviolet or visible light into the standard Fenton system can significantly improve the treatment efficiency and degradation degree of organic matter. In addition, the wastewater channel on the back panel of the solar cell can collect wastewater and utilize unused thermal energy.

[0020] (3) It can efficiently purify different types of wastewater according to needs. It only requires the addition of high-temperature sensitive Fenton catalytic reagent and the use of photo-Fenton reaction to achieve the purification of polluted water.

[0021] This invention integrates power generation and water purification functions, making it particularly suitable for solving industrial wastewater treatment problems. It also achieves more efficient utilization of the full spectrum of solar energy and has broad application prospects. Attached Figure Description

[0022] Figure 1 and Figure 2 This is a schematic diagram of the wastewater treatment system based on photo-Fenton reaction and PV-TEG provided in the embodiments of this application;

[0023] Figure 3 This is a schematic diagram of the wastewater purification circulation system and the heat collection system in the embodiments of this application;

[0024] Figure 4 This is a schematic diagram of the photovoltaic electrochemical treatment system in the embodiments of this application. Detailed Implementation

[0025] The invention will now be further described with reference to the accompanying drawings.

[0026] Appendix Figures 1 to 4 The accompanying figure labels are as follows:

[0027] 1. MPPT unit; 2. Low-iron glass; 3. Photo-Fenton wastewater treatment pipeline; 4. Photovoltaic module; 5. Wastewater flow channel; 6. Thermoelectric module; 7. Light-absorbing thin film material; 8. Hot water storage tank; 9. Heat extraction control valve; 10. Conversion and transmission device; 11. Inlet valve; 12. Positive and negative electrode plates; 13. Heat collection system; 14. Water storage tank; 15. Control valve; 16. Circulating water pump; 17. Heat exchange control valve; 18. Heat exchange circulating water pump; 19. Outlet valve; 20. Wastewater purification and circulation system; 21. Optical concentrator; 22. Photovoltaic electrochemical treatment system.

[0028] like Figures 1 to 4 As shown, a wastewater treatment system based on photo-Fenton reaction and PV-TEG includes a wastewater purification and circulation system 20, a heat collection system 13, a photovoltaic electrochemical treatment system 22, a photovoltaic module 4, and a thermoelectric module 6. The wastewater purification and circulation system 20 includes a wastewater flow channel 5, a photo-Fenton wastewater treatment pipeline 3, and a water storage tank 14. One end of the wastewater flow channel 5 is equipped with an inlet valve 11 for introducing wastewater to be treated, and the other end is connected to one end of the photo-Fenton wastewater treatment pipeline 3 through a pipeline. A circulation loop including a circulating water pump 16 and a control valve 15 is established between the other end of the photo-Fenton wastewater treatment pipeline 3 and the water storage tank 14. An outlet valve 19 is provided on the water storage tank 14.

[0029] A Fenton process wastewater treatment pipe 3 is arranged on the front of the photovoltaic module 4, and the top of the Fenton process wastewater treatment pipe 3 is made of low-iron glass 2 with high solar spectral transmittance. A wastewater flow channel 5 is arranged between the back of the photovoltaic module 4 and the cold end of the thermoelectric module 6, which serves to cool both the photovoltaic module 4 and the thermoelectric module 6 simultaneously. A light-absorbing thin layer material 7 is provided on the surface of the thermoelectric module 6, and an optical concentrator 21 is provided at the bottom of the thermoelectric module 6.

[0030] The photovoltaic electrochemical treatment system 22 includes positive and negative electrode plates 12 disposed in the water storage tank 14. The photovoltaic module 4 utilizes the photovoltaic effect to directly convert solar radiation energy into electrical energy, which is then applied to the water storage tank 14 via the positive and negative electrode plates 12 to further treat the wastewater already treated in the Fenton process wastewater treatment pipeline 3. Excess electrical energy from the photovoltaic module 4 is stored in a battery via the MPPT unit 1 and the conversion and transmission device 10. The electrical energy generated by the thermoelectric module 6 can also be stored in the battery. The MPPT unit 1 and the conversion and transmission device 10 are existing technologies and will not be described in detail here.

[0031] The heat collection system 13 includes a hot water storage tank 8. A heat exchange circulation loop, including a heat exchange circulating water pump 18 and a heat exchange control valve 17, is established between the hot water storage tank 8 and the water storage tank 14. This loop is used to transfer heat to the hot water storage tank 8 when the temperature in the water storage tank 14 reaches a certain value. The hot water storage tank 8 is connected to one end of a sewage channel 5. The water in the hot water storage tank 8 returns to the Guangfenton process sewage treatment pipeline 3 through the sewage channel 5 for purification treatment (before the sewage treatment is completed, the water pumped into the hot water storage tank 8 is still sewage). In addition, a heat exchange coil is installed in the hot water storage tank 8. The hot water storage tank 8 supplies heat to the outside through a heat exchange circulation loop including the heat exchange coil, the heat extraction control valve 9, and the heat extraction circulating water pump (not shown in the figure).

[0032] The control valves in each of the above circulation loops are used to control the opening and closing of the pipeline and to regulate the flow rate.

[0033] In this embodiment, the Fenton process wastewater treatment pipe 3 is surrounded by aluminum materials on all sides, low-iron glass 2 on top, and the outer glass of the photovoltaic module 4. The water is in direct contact with the outer glass of the photovoltaic module 4, and the excess heat in the photovoltaic module 4 is carried away through the circulation of the water. At the same time, the heat will also play a catalytic role in the wastewater treatment process.

[0034] The optical concentrator 21 has a concave structure and is rotatably mounted on the bracket. Adjusting the tilt angle of the optical concentrator 21 can adapt to the incident angle of sunlight from various directions.

[0035] The light-absorbing thin-film material 7 is a black light-absorbing structure with the ability to absorb the entire solar spectrum, and the absorption rate is greater than 90%.

[0036] The working principle of the wastewater treatment system based on photo-Fenton reaction and PV-TEG provided in this application embodiment is as follows:

[0037] During the initial system startup, a certain proportion of Fenton catalyst is added to the sewage flow channel 5. Sunlight passes through the low-iron glass 2 and enters the photo-Fenton wastewater treatment pipe 3. The ultraviolet light, combined with the Fenton catalyst, enhances the efficiency of organic matter treatment and the degree of organic matter degradation. The energy of the visible light portion of the solar spectrum is absorbed by the photovoltaic module 4 through the water to generate electricity. The remaining unused energy is collected by the sewage in the sewage flow channel 5 and, under the action of the circulating water pump 16, the heat is transferred to the photo-Fenton wastewater treatment pipe 3 to purify the sewage through the photo-Fenton reaction.

[0038] Meanwhile, another portion of the incident solar radiation is reflected and focused onto the light-absorbing thin film material 7 by the optical concentrator 21, achieving efficient absorption of solar radiation. The absorbed energy is conducted through heat transfer at the hot and cold ends of the thermoelectric module 6, generating a heat transfer temperature difference and thus generating electrical energy. The remaining energy is also collected through the sewage in the sewage channel 5, and the heat is transferred to the photo-Fenton wastewater treatment pipeline 3, providing a catalytic effect for photo-Fenton wastewater treatment and electrochemical wastewater treatment.

[0039] After being treated by the photo-Fenton process, the wastewater enters the storage tank 14. The flow rate in the pipeline can be adjusted by regulating the opening of the control valve 15. The electricity generated by the photovoltaic module 4 is used to electrolyze the wastewater in the storage tank 14 through the positive and negative electrode plates 12. The current transfers electrons between the positive and negative electrodes to the electrolyte, causing a chemical reaction that decomposes organic and inorganic pollutants, converting them into more stable and harmless products, thus further purifying the wastewater.

[0040] When there is a need for heat extraction, the heat can be extracted and utilized through the heat extraction control valve 9 and the heat extraction circulating water pump.

[0041] In addition, when the water in the storage tank 14 reaches a certain temperature, heat transfer and compensation can be achieved through the cooperation of the heat exchange circulating water pump 18 and the heat exchange control valve 17.

[0042] The electricity generated by the photovoltaic module 4 can be stored in any battery through the MPPT unit 1 and the conversion and transmission device 10. The electricity generated by the thermoelectric module 6 can also be stored in a battery and used when there is a power demand.

Claims

1. A wastewater treatment system based on photo-Fenton reaction and PV-TEG, characterized in that, The system includes a wastewater purification and circulation system (20), a photovoltaic module (4), and a thermoelectric module (6). The wastewater purification and circulation system (20) includes a wastewater flow channel (5), a photo-Fenton wastewater treatment pipeline (3), and a water storage tank (14). One end of the wastewater flow channel (5) is equipped with an inlet valve (11) for introducing wastewater to be treated, and the other end is connected to one end of the photo-Fenton wastewater treatment pipeline (3) through a pipeline. A circulation loop including a circulating water pump (16) is established between the other end of the photo-Fenton wastewater treatment pipeline (3) and the water storage tank (14). An outlet valve (19) is installed on the water storage tank (14). The Fenton process wastewater treatment pipe (3) is arranged on the front of the photovoltaic module (4), and the top of the Fenton process wastewater treatment pipe (3) is made of low iron glass (2) with high solar spectrum transmittance; the wastewater flow channel (5) is arranged between the back of the photovoltaic module (4) and the cold end of the thermoelectric module (6), and the surface of the thermoelectric module (6) is provided with a light-absorbing thin layer material (7), and the bottom of the thermoelectric module (6) is provided with an optical concentrator (21). At the initial stage of system startup, a certain proportion of Fenton catalyst is added to the sewage channel (5). Sunlight shines through the low-iron glass (2) into the photo-Fenton sewage treatment pipeline (3). Ultraviolet light, in conjunction with the Fenton catalyst, treats and degrades organic matter. The energy of the visible light portion of the solar spectrum is absorbed by the photovoltaic module (4) through the water to generate electricity. The remaining unused energy is collected through the sewage in the sewage channel (5) and transferred to the photo-Fenton sewage treatment pipeline (3). Another part of the incident solar radiation is reflected and focused onto the light-absorbing thin film material (7) by the optical concentrator (21). The absorbed energy is conducted through the hot and cold ends of the thermoelectric module (6). The hot and cold ends of the thermoelectric module (6) generate a heat transfer temperature difference and generate electricity. The remaining part of the energy is also collected through the sewage in the sewage channel (5) and transferred to the photo-Fenton sewage treatment pipeline (3).

2. The wastewater treatment system based on photo-Fenton reaction and PV-TEG according to claim 1, characterized in that, It also includes a photovoltaic electrochemical treatment system (22), which includes positive and negative electrode plates (12) installed in a water storage tank (14). The positive and negative electrode plates (12) are powered by the electrical energy generated by the photovoltaic module (4), and excess electrical energy is stored in a battery through the MPPT unit (1) and the conversion and transmission device (10). The electrical energy generated by the thermoelectric module (6) can also be stored in the battery.

3. The wastewater treatment system based on photo-Fenton reaction and PV-TEG according to claim 1, characterized in that, It also includes a heat collection system (13), which includes a hot water storage tank (8). A heat exchange circulation loop including a heat exchange circulation pump (18) is established between the hot water storage tank (8) and the water storage pool (14) to transfer heat to the hot water storage tank (8) when the temperature in the water storage pool (14) reaches a certain value.

4. The wastewater treatment system based on photo-Fenton reaction and PV-TEG according to claim 3, characterized in that, The hot water storage tank (8) is connected to one end of the sewage channel (5). The water in the hot water storage tank (8) returns to the Guangfenton process sewage treatment pipeline (3) through the sewage channel (5) for purification treatment.

5. The wastewater treatment system based on photo-Fenton reaction and PV-TEG according to claim 3, characterized in that, The hot water storage tank (8) is equipped with a heat exchange coil, and the hot water storage tank (8) supplies heat to the outside through a heat extraction circulation loop including the heat exchange coil and the heat extraction circulation pump.

6. The wastewater treatment system based on photo-Fenton reaction and PV-TEG according to any one of claims 1 to 5, characterized in that, Each circulation loop is equipped with control valves for controlling the on / off state and regulating the flow rate.

7. The wastewater treatment system based on photo-Fenton reaction and PV-TEG according to claim 1, characterized in that, The light-Fenton process wastewater treatment pipeline (3) is surrounded by aluminum on all sides, low-iron glass (2) on top, and outer glass of photovoltaic module (4).

8. The wastewater treatment system based on photo-Fenton reaction and PV-TEG according to claim 1, characterized in that, The optical concentrator (21) has a concave structure and is rotatably mounted on the support. Adjusting the tilt angle of the optical concentrator (21) can adapt to the incident angle of sunlight in various directions.

9. The wastewater treatment system based on photo-Fenton reaction and PV-TEG according to claim 1, characterized in that, The light-absorbing thin-layer material (7) has the ability to absorb the entire solar spectrum.

10. The wastewater treatment system based on photo-Fenton reaction and PV-TEG according to claim 9, characterized in that, The light-absorbing thin-layer material (7) has a black light-absorbing structure with an absorption rate of more than 90%.

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