High-salinity waste heat sewage treatment system and method based on light energy and osmotic energy self-power supply

Abstract

Disclosed are a high-salinity waste heat sewage treatment system and method based on self-power supply of light energy and osmotic energy, in which the high-salinity waste heat sewage is subjected to pretreatment and nanofiltration to remove impurities such as oil stains and organic matter; the sewage is branched by a three-way valve to a dilution unit to obtain low-salinity sewage; the high-salinity waste heat sewage is introduced into a high-concentration tank of an ion osmotic power generation device through a first valve, a third valve and a fifth valve, and the low-salinity waste heat sewage is introduced into a low-concentration tank of the ion osmotic power generation device through a second valve and a fourth valve, and ion migration is driven to generate power under the action of osmotic energy; the electric energy of the ion osmotic power generation is coupled with photovoltaic power generation and photo-thermal power generation to be stored in a storage battery group to supply power to a capacitive deionization device, so that self-power supply of the system is realized; the sewage is introduced into the capacitive deionization device at a certain speed through a sixth valve to remove salt; and the deionized water is branched by a three-way valve to flow into the dilution unit and to be subjected to final treatment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sewage treatment, and particularly relates to a high-salinity waste heat sewage treatment system and method based on light energy and osmotic energy self-power supply. BACKGROUND

[0002] Many chemical enterprises will produce a large amount of high-salinity waste heat sewage in the production process. If the sewage is directly discharged into the water body without treatment or unqualified treatment, water pollution will be caused, and the shortage of water resources will be aggravated. Some organic matters and ions in the high-salinity waste heat sewage will be immersed into the surface water, soil and even underground water, hinder the normal growth and reproduction of microorganisms and plants in them, and destroy the normal metabolism of organisms, so that the degradation capacity of the organisms is reduced. Therefore, it is urgent to comprehensively consider various factors to treat the high-salinity waste heat sewage.

[0003] The physical and chemical treatment method of the high-salinity waste water includes coagulation flocculation, electrolysis and the like, but the separated substances are not easy to be recycled and the cost is high. The membrane treatment method of the high-salinity waste water includes microfiltration, nanofiltration and the like, but the defects are that the membrane holes are easy to be blocked and the service life of the membrane is low. The biological treatment method of the high-salinity waste water has aerobic and anaerobic types and the like, but the microbial method is harsh in conditions, and the microorganisms will be separated from the cell wall and even die in the high-salinity environment. In addition, the treatment of the high-salinity waste heat sewage usually consumes a large amount of electric energy. In summary, a new method for solving the problems of electric energy and sewage is urgently needed.

[0004] The information disclosed in the background section merely serves to enhance the understanding of the background of the present application, and therefore can contain information that is not prior art known to those of ordinary skill in the art. SUMMARY

[0005] In view of the deficiencies or defects of the prior art, a high-salinity waste heat sewage treatment system and method based on light energy and osmotic energy self-power supply are provided. Light energy, as the largest renewable natural resource of human beings, has the characteristics of being clean, cheap and inexhaustible, and has become an important direction for solving the dual crisis of energy and environment. The ion salt difference power generation technology generates power by using salinity difference, has the advantages of high power density, green and clean, and is very suitable for high-salinity waste heat sewage treatment. Capacitive deionization is an electric adsorption desalination technology, which does not need high pressure or membrane structure, and the device structure is simple, and has unique advantages in energy efficiency, environmental friendliness and ion removal rate. The present application can efficiently, lowly and sustainably supply power to the capacitive deionization sewage treatment by light energy and osmotic energy.

[0006] The object of the present application is achieved by the following technical solutions.

[0007] A high-salinity waste heat sewage treatment system based on light energy and osmotic energy self-power supply comprises,

[0008] The flow path module comprises,

[0009] a sewage pretreatment unit for precipitating high-salinity waste heat sewage to be treated to separate oil stains;

[0010] a nanofiltration membrane connected to the sewage pretreatment unit for nanoscale filtration of organic matters;

[0011] a first three-way valve connected to the nanofiltration membrane for splitting high-salinity waste heat sewage after nanofiltration;

[0012] a dilution unit connected to the first three-way valve and a capacitive deionization device for diluting high-salinity waste heat sewage after nanofiltration with deionized water after desalination of the capacitive deionization device to obtain low-salinity sewage;

[0013] an ion permeation power generation device connected to the first three-way valve and the dilution unit for permeation power generation using high-salinity waste heat sewage after nanofiltration and low-salinity waste heat sewage;

[0014] a capacitive deionization device connected to the ion permeation power generation device via a sixth valve for generating deionized water after desalination, the capacitive deionization device comprising charged electrodes for adsorbing anions and cations in a solution respectively to desalinate;

[0015] a second three-way valve connected to the capacitive deionization device, the dilution unit, and a water outlet final treatment unit respectively for splitting deionized water after desalination from the capacitive deionization device to the dilution unit and the water outlet final treatment unit;

[0016] a circuit module comprising,

[0017] a photovoltaic panel for receiving light energy and converting it into electrical energy;

[0018] a light concentrator for receiving light energy and concentrating the heat energy generated by the light to a photo-thermal power generator,

[0019] a photo-thermal power generator for receiving photo-thermal energy and converting it into electrical energy;

[0020] a battery pack for connecting the photovoltaic panel, the photo-thermal power generator, the ion permeation power generation device, and the capacitive deionization device to store electrical energy and supply electrical energy to the capacitive deionization device.

[0021] In the system, the ion permeation power generation device comprises positive and negative electrodes on both sides, anion exchange membranes and cation exchange membranes arranged alternately between the positive and negative electrodes, and high-concentration pools and low-concentration pools between the anion exchange membranes and the cation exchange membranes.

[0022] The system, the high concentration pool is communicated with the first three-way valve by the first valve, the third valve and the fifth valve at a first flow rate to receive high-salinity waste heat sewage, and the low concentration pool is communicated with the dilution unit by the second valve and the fourth valve at a second flow rate to receive low-salinity waste heat sewage.

[0023] The system, the channel structure of the anion exchange membrane and the cation exchange membrane is a tapered channel structure, and the end with a small pore size faces the low concentration pool.

[0024] The system, the dilution unit is provided with a desalination capacitive deionization device or a reverse electrodialysis device.

[0025] The system, the capacitive deionization device further comprises an electrode adsorption material, and the electrode adsorption material comprises activated carbon fiber, carbon aerogel and carbon nanotube.

[0026] The system, the circuit module further comprises a chemical heat storage material for storing excess light heat energy, and the chemical heat storage material comprises carbonate, metal oxide and hydrated salt.

[0027] The system, the battery pack is a series-parallel connection structure of multiple batteries, and the batteries comprise lead-acid batteries, nickel-hydrogen batteries, lithium ion batteries and sodium ion batteries.

[0028] The method of the high-salinity waste heat sewage treatment system based on light energy and osmotic energy self-power supply comprises the following steps:

[0029] S1: After the high-salinity waste heat sewage is subjected to pretreatment and nanofiltration to remove oil stains and organic matter, the high-salinity waste heat sewage is branched by the first three-way valve to the dilution unit to obtain low-salinity sewage;

[0030] S2: The high-salinity waste heat sewage is branched into the high concentration pool of the ion osmotic power generation device, and the low-salinity waste heat sewage is branched into the low concentration pool of the ion osmotic power generation device, and ion migration is driven under the action of osmotic energy to generate electricity;

[0031] S3: The electrical energy generated by the ion osmotic power generation is coupled with photovoltaic power generation and photo-thermal power generation to be stored in a battery pack to supply power to a capacitive deionization device, so that the system is self-powered;

[0032] S4: The sewage is introduced into the capacitive deionization device at a certain speed through the sixth valve to remove salt to obtain deionized water; the deionized water is branched by the second three-way valve to flow into the dilution unit and part of the deionized water is subjected to final treatment.

[0033] Compared with the prior art, the present disclosure has the following beneficial effects:

[0034] The present disclosure recovers light energy and osmotic energy in high-salt waste heat sewage and generates electricity, which can realize system self-power supply without external power supply. Moreover, the thermochemical energy storage material in the photo-thermal power generation can further recover light-thermal energy to generate electricity. The storage battery ensures the continuity and stability of electricity. The sewage flow rate of the ion salt differential power generation device of the present disclosure can be controlled by the first valve, the second valve, the third valve, the fourth valve and the fifth valve, combined with the temperature influence of waste heat in the sewage, which can greatly weaken the ion concentration polarization effect and improve the power generation capacity. The ion salt differential power generation device can further improve the power generation performance. The electrode material of the capacitive deionization device of the present disclosure is diverse, and the electrode material with high conductivity, large specific surface area and reasonable pore size distribution is selected to further improve the capacitive deionization desalination performance. The present disclosure meets the beneficial effects of high efficiency, clean, green, low carbon, low energy consumption and sustainability.

[0035] The description is only a summary of the technical solutions of the present application. In order to make the technical means of the present application clearer and more understandable, and to enable the person skilled in the art to implement the content of the description, and to enable the described and other purposes, features and advantages of the present application to be more obvious and easy to understand, the following is an example of the specific embodiments of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0036] Various other advantages and benefits of the present application will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are for purposes of illustration only and are not to be construed as limiting the application. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained from these drawings without creative labor for those of ordinary skill in the art. Moreover, the same reference numerals are used to represent the same components throughout the drawings.

[0037] In the drawings:

[0038] Fig. 1 The structure schematic diagram of the high-salt waste heat sewage treatment system based on light energy and osmotic energy self-power supply provided for an embodiment of the present disclosure is shown in the figure;

[0039] Fig. 2 The structure schematic diagram of the ion salt differential power generation device of the high-salt waste heat sewage treatment system based on light energy and osmotic energy self-power supply provided for another embodiment of the present disclosure is shown in the figure;

[0040] Fig. 3 The concentration polarization regulation result diagram of the ion salt differential power generation device of the high-salt waste heat sewage treatment system based on light energy and osmotic energy self-power supply provided for another embodiment of the present disclosure is shown in the figure.

[0041] The application will be further explained with reference to the accompanying drawings and examples. DETAILED DESCRIPTION

[0042] The application will be further explained with reference to the accompanying drawings and examples. Figs. 1 to 3 The application will be further explained with reference to the accompanying drawings and examples.

[0043] It should be noted that certain terms have been used throughout the specification and claims which have been used for descriptive purposes only and thus should not be construed as limiting. It is intended that the description and claims be considered as including all possible combinations of conditions and features as described herein.

[0044] For the purpose of promoting an understanding of the principles of the application, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will, nevertheless, be understood that no limitation of the scope of the application is intended by this description. The application is to be construed as including all features which occur to those skilled in the art in this or analogous arts, following the principles of the application and including present or future equivalents.

[0045] For a better understanding of the application, reference will be made to the following examples and to the accompanying drawings in which: Fig. 1 As shown in the drawings, a high-salinity waste heat sewage treatment system based on light energy and osmotic energy self-power supply includes a flow path module and a circuit module; wherein,

[0046] The flow path module is used for pretreating high-salinity waste heat sewage, guiding the sewage into an ion osmotic power generation device 5 to generate power, guiding the sewage into a capacitive deionization device 8 to remove salt, and then guiding the treated water into a low-salinity pool of the ion osmotic power generation device 5 to ensure a salt difference, and finally performing final treatment on another part of the treated water for application.

[0047] The circuit module is used for collecting the energy of photovoltaic power generation, photo-thermal power generation, and the ion osmotic power generation device 5 in the flow path module, storing the electric energy in a battery pack 11, and simultaneously supplying power to the capacitive deionization device 8 in the flow path module.

[0048] Preferably, the flow path module includes,

[0049] The sewage pretreatment unit 1 precipitates high-salinity waste heat sewage to be treated to separate impurities such as oil stains.

[0050] a nanofiltration membrane 2 for filtering impurities such as organic matters at nanometer scale;

[0051] a first three-way valve 3 for diverting the water after nanofiltration;

[0052] a dilution unit 4 for receiving a portion of the water purified by the capacitive deionization device 8 and diluting a portion of the high-salinity waste heat sewage filtered by the nanofiltration membrane 2 to obtain low-salinity sewage;

[0053] a first valve 16, a second valve 17, a third valve 18, a fourth valve 19, and a fifth valve 20 for controlling the speed of the sewage entering the ion permeation power generation device 5;

[0054] an ion permeation power generation device 5 for generating power by permeation of the high-salinity waste heat sewage and the low-salinity waste heat sewage from the dilution unit 4 and being connected to the battery pack 11 for energy storage;

[0055] a sixth valve 21 for controlling the speed of the sewage entering the capacitive deionization device 8;

[0056] a capacitive deionization device 8 for adsorbing the anions and cations in the solution on the surface of the electrodes with the charged electrodes to achieve the desalination effect;

[0057] a second three-way valve 9 for diverting the deionized water after desalination;

[0058] a water outlet final treatment unit 10 for receiving the deionized water after desalination and performing preparation treatment before actual application.

[0059] Preferably, the circuit module comprises,

[0060] a photovoltaic panel 15 for receiving light energy and converting it into electrical energy;

[0061] a light concentrator 12 for receiving light energy and concentrating the heat energy generated by light to the photo-thermal power generator;

[0062] a photo-thermal power generator 14 for receiving photo-thermal energy and generating power by photo-thermal energy conversion;

[0063] a chemical heat storage material 13 for storing excess photo-thermal energy;

[0064] a battery pack 11 for connecting the photovoltaic panel 15, the photo-thermal power generator 14, and the ion permeation power generation device 5 to store electrical energy and connecting the capacitive deionization device 8 for power supply.

[0065] Preferably, the dilution unit 4 receives a portion of the water purified by the capacitive deionization device 8 for dilution, and a capacitive deionization device 8 or a reverse electrodialysis device can be arranged in the unit to perform preliminary desalination to obtain low-salinity water.

[0066] Preferably, the chemical heat storage material 13 can achieve long-time heat energy storage, solving the problem of intermittent instability of light-thermal energy. It includes but is not limited to carbonates, metal oxides, and hydrated salts, etc.

[0067] Preferably, the battery pack 11 adopts a multi-battery series-parallel structure to improve the output voltage and capacity to achieve the system self-power supply effect. The battery types include but are not limited to lead-acid batteries, nickel-hydrogen batteries, lithium-ion batteries, and sodium-ion batteries.

[0068] In one embodiment, the sewage pretreatment unit includes a sedimentation tank for sedimentation of high-salinity waste heat sewage to be treated. Further, the sewage pretreatment unit includes an adsorption tank for removing oil stains.

[0069] To quantitatively show the feasibility of the light energy-based and osmotic energy self-powered system, Table 1 gives the power generation of photovoltaic power generation, photo-thermal power generation, and ion permeation power generation, and the power consumption of the capacitive deionization device for comparison.

[0070] Table 1 Comparison of system daily power generation and daily power consumption

[0071]

[0072] The photovoltaic power generation device selects a photovoltaic panel with a length of 2 meters and a width of 1 meter, with a power generation of 360W. Based on 4 hours of sufficient light during the day, the daily power generation is estimated to be 1.44kWh. The photo-thermal power generation device selects a condenser with a chord length of 3 meters and a length of 1 meter, and the photo-thermal power generation of the photo-thermal power generation device has a photo-thermal conversion efficiency of 12%, with a power generation of 140W. Based on 4 hours of light during the day plus 4 hours of heat release of the chemical heat storage material, the daily power generation is 1.12kWh. The ion permeation power generation device 5 has a single membrane power generation power density of 10W / m 2 , assuming that the ion permeation power generation device 5 has a total of 5 membranes with a length of 1 meter and a width of 1 meter for power generation, with a power generation of 50W, and a working time of 24 hours, the daily power generation is 1.2kWh. The system daily power generation is 3.76kWh in total. The power consumption of the capacitive deionization device 8 is 96W, and the working time is 24 hours, and the daily power consumption is 2.3kWh. In summary, the system daily power generation is greater than the daily power consumption, and the system self-power supply can be completed. In addition, 14 12-volt 100-ampere-hour batteries are used in series, with a total storage capacity of 16.8kWh, which can power the capacitive deionization device 8 to work alone for more than 1 week without power generation equipment.

[0073] In one embodiment, as Fig. 2As shown, the ion permeation power generation device 5 includes positive and negative electrodes, an anion exchange membrane 7, a cation exchange membrane 6, high concentration pools and low concentration pools between the ion exchange membranes. The number of the anion exchange membrane 7, the cation exchange membrane 6, the high concentration pools and the low concentration pools between the ion exchange membranes should be adjusted according to the actual situation, and the number of valves should be adjusted accordingly. The channel structure of the anion exchange membrane 7 and the cation exchange membrane 6 includes but is not limited to a tapered channel structure, and the end with a small pore size is directed towards the low concentration pool to enhance the power generation process. This can be explained by the selectivity of the double electric layer. The Debye length formula of the double electric layer is as follows:

[0074]

[0075] where λ D is the Debye length, ε is the dielectric constant, R g is the universal gas constant, T is the temperature, F is the Faraday constant, and I c is the ionic strength. I c is positively correlated with the ion concentration. As can be seen from the Debye length formula of the double electric layer, the ion concentration in the low concentration pool is small, resulting in a small ionic strength I c , so the Debye length is large, and therefore the double electric layer is large. Directing the end with a small pore size of the tapered channel towards the low concentration pool can further increase the degree of overlap of the double electric layer, increase the ion selectivity of the channel, and enhance the power generation. Similarly, the channel structure of the anion exchange membrane 7 and the cation exchange membrane 6 can also be a composite membrane structure of a straight channel with a large radius, and the end with a small pore size is directed towards the low concentration pool. Similarly, the surface of the channel near the low concentration pool can also be roughened.

[0076] In one embodiment, as shown in Fig. 3 , the high concentration pool receives high-salt waste heat sewage at a certain flow rate through the first valve 16, the third valve 18, and the fifth valve 20, and the low concentration pool receives low-salt waste heat sewage at a certain flow rate through the second valve 17 and the fourth valve 19. The flow rate and waste heat temperature distribution are adjusted to weaken the ion concentration polarization effect and improve the power generation performance of the ion permeation power generation device 5. The control equation of the ion salt difference power generation is as follows:

[0077] Poisson equation:

[0078] Nernst-Planck equation:

[0079] Continuity equation:

[0080] Navier-Stokes equation:

[0081] Fluid energy equation:

[0082] Solid energy equation:

[0083] where, is the partial differential operator, ε is the permittivity, φ is the electric potential, F is the Faraday constant, c i is the ion concentration of the i-th ion, z i is the valence charge number of the i-th ion, D i is the diffusion coefficient of the i-th ion, α i is the reduced Soret coefficient of the i-th ion, J i is the ion flux of the i-th ion, where i = 1 represents the cation and i = 2 represents the anion, u is the velocity, R g is the universal gas constant, T is the temperature, p is the pressure, μ is the dynamic viscosity, a is the thermal diffusivity, k f is the fluid thermal conductivity, k s is the solid thermal conductivity, σ f is the electrical conductivity.

[0084] To quantitatively characterize the influence of velocity and temperature regulation on the power generation performance of the ion permeation power generation device 5, the Poisson-Nernst-Planck equation coupled with the Navier-Stokes equation and the energy equation were solved by the finite element method to simulate the ion salt difference power generation in the nanochannel of the ion permeation power generation device 5. Table 2 shows the comparison of the results with and without velocity and temperature regulation in the nanochannel.

[0085] Table 2 Comparison of results with and without velocity and temperature regulation in the nanochannel

[0086]

[0087] The model without velocity and temperature regulation is given an external flow rate of 0 and a temperature of 20 degrees. The model with velocity and temperature regulation is given an external flow rate of 0.02 m / s and a temperature of 40 degrees. As can be seen from Table 2, the effective concentration ratio and power density of the nanochannel with velocity and temperature regulation are greatly improved compared to those without velocity and temperature regulation. The effective concentration ratio increases from 4.25 to 8.01, an increase of 88.47%; the power density increases from 9.57 W·m -2 to 21.43 W·m -2 , an increase of 123.93%. This is because velocity and temperature can greatly weaken the ion concentration polarization phenomenon, so that a higher concentration ratio is maintained at both ends of the nanochannel, and power generation is more effective. In addition, the increase in temperature also affects the properties of ion salt difference power generation, such as increasing the ion diffusion coefficient and reducing the solvent viscosity. This is more conducive to ion migration, and therefore more conducive to power generation.

[0088] In another embodiment, the capacitive deionization device 8 includes positive and negative electrodes, electrode adsorption materials. The electrode adsorption materials include, but are not limited to, activated carbon fiber, carbon aerogel and carbon nanotube. The capacitive deionization device 8 can desalinate at low pressure and room temperature, with low operating voltage or current, without coupling with high-pressure pumps or heat sources, so it has low energy consumption and the size of the desalination system can be flexibly scaled. The capacitive deionization device 8 has charge-discharge cycle capability and energy storage capability, so it can realize desalination while storing energy.

[0089] In another embodiment, a method of a high-salinity waste heat sewage treatment system based on light energy and osmotic energy self-power supply includes the following steps:

[0090] S1: The high-salinity waste heat sewage is subjected to pretreatment unit 1 and nanofiltration membrane 2 to remove impurities such as oil stains and organic matter; through the first three-way valve 3, the sewage is branched to the dilution unit 4 to obtain low-salinity sewage;

[0091] S2: The high-salinity waste heat sewage passes through the first valve 16, the third valve 18 and the fifth valve 20 to enter the high-concentration pool of the ion osmotic power generation device 5, and the low-salinity waste heat sewage passes through the second valve 17 and the fourth valve 19 to enter the low-concentration pool of the ion osmotic power generation device 5, which drives ion migration to generate electricity under the action of osmotic energy;

[0092] S3: The electrical energy of the ion osmotic power generation is coupled with photovoltaic power generation and photo-thermal power generation to store in the battery pack 11 to supply power to the capacitive deionization device 8, realizing self-power supply of the system;

[0093] S4: The sewage is passed into the capacitive deionization device 8 at a certain speed through the sixth valve 21 to remove salt; through the second three-way valve 9, part of the deionized water is flowed into the dilution unit 4, and part of the deionized water is subjected to the water outlet final treatment 10.

[0094] Industrial applicability

[0095] The high-salinity waste heat sewage treatment system and method based on light energy and osmotic energy self-power supply can be manufactured and used in the field of sewage treatment.

[0096] The above describes the basic principles of the present application in combination with specific embodiments, but it should be pointed out that the advantages, advantages, effects and the like mentioned in the present application are only examples and not limitations, and these advantages, advantages, effects and the like cannot be considered as the must-have of each embodiment of the present application. In addition, the above specific details are only for the purpose of example and for the purpose of understanding, and are not limited to the present application, and the above specific details are not limited to the present application.

[0097] The foregoing description has been presented for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the application to the forms disclosed herein. Although various example aspects and embodiments have been discussed above, those of ordinary skill in the art will appreciate a variety of modifications, alternatives, permutations, additions, and sub-combinations, which fall within the scope of the application.

Claims

1. A high-salt waste heat sewage treatment system based on self-powered light energy and osmotic energy, characterized in that: It includes: A flow path module comprising: A sewage pretreatment unit, which precipitates the high-salt waste heat sewage to be treated to separate the oil; a nanofiltration membrane connected to the sewage pretreatment unit to filter organic matter at a nanometer scale; A first three-way valve connected to the nanofiltration membrane to divert the high-salt waste heat and sewage after nanofiltration; a dilution unit connected to the first three-way valve and the capacitive deionization device to dilute the high-salinity waste heat sewage after nanofiltration with the deionized water after desalination by the capacitive deionization device to obtain low-salinity sewage; an ion osmosis power generation device connected to the first three-way valve and the dilution unit to perform osmotic power generation using the high-salt waste heat sewage after nanofiltration and the low-salt waste heat sewage; a capacitive deionization device connected to the ion osmosis power generation device via a sixth valve to generate deionized water after desalination, the capacitive deionization device comprising charged electrodes for adsorbing anions and cations in the solution to remove salt; a second three-way valve, which is connected to the capacitive deionization device, the dilution unit and the effluent final treatment unit respectively to divert the deionized water after desalination from the capacitive deionization device to the dilution unit and the effluent final treatment unit; A circuit module comprising: Photovoltaic panels, which receive light energy and convert it into electricity; A concentrator for receiving light energy and concentrating the heat energy generated by the light to a photothermal power generator; Photothermal generators, which receive photothermal energy and convert it into electricity; A battery pack is used to connect photovoltaic panels, photothermal generators, ion osmosis power generation devices and capacitor deionization devices to store electrical energy and supply electrical energy to the capacitor deionization device. The ion osmosis power generation device includes positive and negative electrodes located on both sides, anion exchange membranes and cation exchange membranes alternately arranged between the positive and negative electrodes, and a high-concentration pool and a low-concentration pool between the anion exchange membrane and the cation exchange membrane. The high-concentration pool is connected to the first three-way valve at a first flow rate through a first valve, a third valve, and a fifth valve to receive high-salt waste heat sewage. The low-concentration pool is connected to the dilution unit at a second flow rate through a second valve and a fourth valve to receive low-salt waste heat sewage. The flow rate and waste heat temperature distribution are regulated to weaken the ion concentration polarization effect and improve the power generation performance of the ion osmosis power generation device. The channel structure of the anion exchange membrane and the cation exchange membrane is a conical channel structure, and the ends with small pore sizes are both facing the low-concentration pool.

2. The system according to claim 1, wherein: A capacitive deionization device or a reverse electrodialysis device for desalination is provided in the dilution unit.

3. The system according to claim 1, wherein: The capacitive deionization device further comprises an electrode adsorption material, which comprises activated carbon fibers, carbon aerogels and carbon nanotubes.

4. The system according to claim 1, wherein: The circuit module also includes a chemical heat storage material for storing excess light and heat energy, wherein the chemical heat storage material includes carbonates, metal oxides, and hydrated salts.

5. The system according to claim 1, wherein: The battery pack is a structure of multiple battery groups connected in series and parallel, and the batteries include lead-acid batteries, nickel-hydrogen batteries, lithium-ion batteries and sodium-ion batteries.

6. A method for treating high-salt waste heat sewage based on self-powered light energy and osmotic energy according to any one of claims 1 to 5, characterized in that: It includes the following steps: S1: The high-salinity waste heat sewage passes through the sewage pretreatment unit and nanofiltration membrane to remove oil and organic matter, and then is diverted to the dilution unit through the first three-way valve to obtain low-salinity waste heat sewage; S2: High-salt waste heat sewage is diverted into the high-concentration pool of the ion osmosis power generation device, and low-salt waste heat sewage is diverted into the low-concentration pool of the ion osmosis power generation device. The osmotic energy drives ion migration to generate electricity; S3: The electric energy generated by ion permeation power generation is coupled with photovoltaic power generation and solar thermal power generation to be stored in a battery bank to power the capacitor deionization device, thus achieving self-powering of the system; S4: The sewage is passed through the sixth valve at a certain speed into the capacitive deionization device for desalination to obtain deionized water; a portion of the deionized water is allowed to flow into the dilution unit through the second three-way valve, and a portion is subjected to final effluent treatment.

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