Waste heat driven membrane distillation water purification device

Abstract

The invention relates to the technical field of water treatment devices, in particular to a waste heat driven membrane distillation water purification device which comprises a membrane distillation reactor, a circulating pipe, a condenser and an oxidizing agent adding device, the membrane distillation reactor is provided with a water inlet component, a water outlet component and a distillation steam outlet, and the water inlet component is communicated with the water outlet component through the circulating pipe; the distilled steam outlet is communicated with the condenser; the oxidant adding device is communicated with the water inlet component and is used for adding peroxydisulfate and percarbonate; a plurality of hollow fiber membranes are arranged in the membrane distillation reactor, and a catalyst is loaded on the inner surfaces of the hollow fiber membranes. According to the invention, industrial waste heat of high-heat wastewater is utilized to activate disulfate and percarbonate to degrade organic matters difficult to degrade in wastewater, meanwhile, a catalyst loaded on the membrane is utilized to synergistically catalyze and degrade pollutants in a water body, and hydrophobic micropores of the hollow fiber membrane drive water vapor to pass through the membrane by utilizing vapor pressure difference inside and outside the membrane so as to realize thorough water purification; the membrane distillation purification efficiency is improved.

Description

Technical Field

[0001] This invention relates to the technical field of water treatment devices, and more specifically, to a waste heat-driven membrane distillation water purification device. Background Technology

[0002] With the rapid development of industry, modern industrial wastewater is characterized by complex composition, high biotoxicity, and high content of recalcitrant organic matter, posing a severe challenge to water environment protection and governance. Traditional biological treatment technologies are inefficient for this type of wastewater, thus often requiring the combination of physicochemical methods for advanced treatment. Membrane distillation, as a heat-driven separation technology, is considered a promising advanced treatment and zero-discharge technology due to its advantages of nearly 100% theoretical rejection rate, utilization of low-grade heat sources, and ability to treat high-salinity wastewater. However, conventional membrane distillation devices face a core dilemma when treating industrial wastewater with complex composition and high concentrations of recalcitrant organic matter: low purification efficiency. This is mainly reflected in two aspects: first, organic matter in the wastewater easily adsorbs and deposits on the membrane surface, rapidly leading to membrane fouling and wetting, significantly reducing transmembrane flux, requiring frequent cleaning or maintenance, and resulting in short effective operating time; second, a large amount of recalcitrant organic matter cannot be effectively destroyed or removed by the phase change separation process driven solely by heat energy, and may ultimately accumulate on the concentration side or affect the quality of the permeate, limiting the overall purification efficiency.

[0003] To enhance the removal capacity of organic matter, advanced oxidation technologies (such as persulfate or percarbonate-based systems) are often considered as potential solutions for co-operation with membrane processes. These technologies can effectively degrade organic matter by generating active free radicals. However, in practical applications, significant bottlenecks remain in improving their purification efficiency. On the one hand, the activation conditions required for advanced oxidation reactions (such as heat, ultraviolet light, and metal catalysis) are disconnected from or compete with the heating process of membrane distillation in terms of energy utilization, failing to achieve efficient synergy and increasing the overall energy consumption of the system. On the other hand, problems such as residual oxidant (such as sulfate ions) and dissolution of catalyst metal ions may exacerbate membrane fouling or corrosion, which in turn restricts the long-term stable operation of the core components of membrane distillation. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of low membrane distillation purification efficiency in the prior art and to provide a waste heat-driven membrane distillation water purification device to improve membrane distillation purification efficiency.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A waste heat-driven membrane distillation water purification device is provided, comprising a membrane distillation reactor, a circulation pipe, a condenser, and an oxidant addition device. The membrane distillation reactor is provided with an inlet component, an outlet component, and a distillation vapor outlet. The inlet component and the outlet component are connected through the circulation pipe, and the distillation vapor outlet is connected to the condenser. The oxidant addition device is connected to the inlet component and is used to add persulfate and percarbonate. The membrane distillation reactor is provided with multiple hollow fiber membranes, and a catalyst is loaded on the inner surface of the hollow fiber membranes.

[0007] The waste heat-driven membrane distillation water purification device of this invention introduces high-heat wastewater into the membrane distillation reactor through the inlet component during purification. Simultaneously, persulfate and percarbonate are added via an oxidant addition device. The high-heat wastewater, persulfate, and percarbonate flow together inside the hollow fiber membrane. The high temperature of the wastewater itself thermally activates the persulfate and percarbonate, degrading recalcitrant organic pollutants in the wastewater. Simultaneously, the catalyst loaded on the membrane synergistically catalyzes the degradation of pollutants in the water, reducing pollutant deposition on the membrane surface and improving membrane distillation purification efficiency. At the high temperature of the wastewater, water vapor, driven by the vapor pressure difference generated by the temperature difference between the inside and outside of the membrane, permeates through the hydrophobic hollow fiber membrane, enters the outer side of the membrane, and enters the condenser from the distillation vapor outlet for condensation. The remaining wastewater enters the circulation pipe through the outlet component and then re-enters the membrane distillation reactor through the inlet component for membrane distillation. By utilizing the industrial waste heat from high-heat wastewater to activate disulfate and percarbonate to degrade recalcitrant organic matter in the wastewater, and simultaneously using a membrane-supported catalyst to synergistically degrade pollutants in the water, the membrane distillation purification efficiency is improved.

[0008] Furthermore, the system also includes a pH detection device and a control system. The pH detection device is located at the water inlet component. Both the pH detection device and the oxidant addition device are electrically connected to the control system. The control system adjusts the addition ratio of persulfate and percarbonate using the oxidant addition device based on the pH value detected by the pH detection device. By adjusting the addition ratio of persulfate and percarbonate according to the pH value detected by the pH detection device, the degradation efficiency across the entire pH range is improved.

[0009] Furthermore, when the pH detection device detects a pH value less than 7, the addition ratio of persulfate to percarbonate is greater than 1; when the pH detection device detects a pH value equal to 7, the addition ratio of persulfate to percarbonate is 1; when the pH detection device detects a pH value greater than 7, the addition ratio of persulfate to percarbonate is less than 1.

[0010] Furthermore, the dosage of the persulfate and the percarbonate satisfies the following relationship with the pH value:

[0011]

[0012] In the formula, This indicates the mass percentage of persulfate in the total mass of persulfate and percarbonate; This indicates the mass percentage of percarbonate in the total mass of perisosulfate and percarbonate; This indicates the pH value.

[0013] Furthermore, the catalyst comprises manganese oxide.

[0014] Furthermore, the system also includes a sulfate ion monitor and a first water quality detector, both of which are installed on the circulation pipe, which has a recovery outlet. When the sulfate ion monitor detects that the sulfate ion concentration in the circulation pipe is higher than a threshold, it stops inputting new wastewater into the inlet component. The original wastewater continues to circulate and be purified until the first water quality detector detects that the water quality meets the standard, at which point the recovery outlet is opened to discharge the water. The treated water with excessively high sulfate ion concentration is discharged for sulfate ion recovery and reuse.

[0015] Furthermore, it also includes a temperature monitoring and sensing component, which is located at the water inlet component, and a stripping mechanism is provided inside the membrane distillation reactor; the temperature of the dry gas blown out in the stripping mechanism is adjusted according to the temperature monitored by the temperature monitoring and sensing component. This reduces the probability of recalcitrant organic pollutants volatilizing and permeating through the hollow fiber membrane.

[0016] Furthermore, a circulation pump is connected to the circulation pipe. The circulation pump drives the wastewater to circulate in the circulation pipe for membrane distillation.

[0017] Furthermore, the hollow fiber membrane is any one of polypropylene membrane, polyvinylidene fluoride membrane, hydrophobically modified ceramic membrane, and polytetrafluoroethylene membrane.

[0018] Furthermore, it also includes a second water quality detector and an ozone reactor. The condenser is connected to the inlet of the second water quality detector, which has a first outlet and a second outlet. The second outlet is connected to the ozone reactor. When the second water quality detector detects that the water condensed by the condenser does not meet the effluent quality standards, the water is discharged through the second outlet to the ozone reactor for secondary treatment.

[0019] Furthermore, the ozone reactor includes a reaction tank, an ozone aeration device, an aeration pump, and an ozone generator. The second outlet is connected to the reaction tank, and the ozone generator, the aeration pump, the ozone aeration device, and the reaction tank are connected in sequence. The ozone generator produces ozone, which enters the ozone aeration device through the aeration pump, and then enters the reaction tank to aerate the water.

[0020] Compared with the prior art, the beneficial effects of the present invention are: 1. The present invention provides a waste heat-driven membrane distillation water purification device, which utilizes industrial waste heat from high-heat wastewater to activate disulfate and percarbonate to degrade recalcitrant organic matter in the wastewater, while simultaneously using a catalyst loaded on the membrane to synergistically catalyze the degradation of pollutants in the water, thereby reducing the deposition of pollutants on the membrane surface and improving the membrane distillation purification efficiency.

[0021] 2. The waste heat driven membrane distillation water purification device of the present invention improves the degradation efficiency across the entire pH range by adjusting the addition ratio of disulfate and percarbonate according to the pH value detected by the pH detection device. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the waste heat-driven membrane distillation water purification device of the present invention in Embodiment 1; Figure 2 This is a schematic diagram comparing the degradation efficiency of the five comparative experiments in Example 2; Figure 3 This is a schematic diagram of the waste heat-driven membrane distillation water purification device of the present invention in Embodiment 3; Figure 4 This is a schematic diagram comparing the degradation efficiency of PDS alone, SPC alone, and SPC / PDS dynamically adjusted combination at different pH levels in Example 3; Figure 5 This is a schematic diagram of the waste heat-driven membrane distillation water purification device of the present invention in Example 4.

[0023] In the attached diagram: 100, membrane distillation reactor; 110, inlet water component; 120, outlet water component; 130, distillation steam outlet; 140, hollow fiber membrane; 200, circulation pipe; 210, sulfate ion monitor; 220, first water quality detector; 230, recovery outlet; 240, circulation pump; 300, condenser; 400, oxidant addition device; 500, pH detection device; 600, control system; 700, temperature monitoring sensor component; 800, second water quality detector; 810, first outlet water; 820, second outlet water; 900, ozone reactor; 910, reaction tank; 920, ozone aeration device; 930, aeration pump; 940, ozone generator. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only, representing schematic diagrams only, not actual pictures, and should not be construed as limiting this patent. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0025] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms describing positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. Furthermore, if the embodiments of the present invention involve descriptions such as "first" and "second," these descriptions are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In addition, the meaning of "and / or" in the text is that it includes three parallel options. Taking "A and / or B" as an example, it includes option A, option B, or an option that satisfies both A and B.

[0026] Example 1 This embodiment is a first embodiment of a waste heat-driven membrane distillation water purification device, such as... Figure 1As shown, the device includes a membrane distillation reactor 100, a circulation pipe 200, a condenser 300, and an oxidant addition device 400. The membrane distillation reactor 100 includes a shell, a water inlet component 110, a water outlet component 120, a distillation steam outlet 130, a stripping mechanism, and multiple hollow fiber membranes 140. The water inlet component 110 is located at the bottom of the shell, the water outlet component 120 is located at the top of the shell, and the distillation steam outlet 130 is located on the side of the shell. Valves are provided at the water inlet component 110, the water outlet component 120, and the distillation steam outlet 130. The stripping mechanism is located at the top of the shell. Perforated plates are provided at the top and bottom of the shell. Multiple hollow fiber membranes 140 are installed and connected to the perforated plates. The hollow fiber membranes 140 are any one of polypropylene membranes, polyvinylidene fluoride membranes, hydrophobically modified ceramic membranes, and polytetrafluoroethylene membranes. In some embodiments, the hollow fiber membrane 140 is a polytetrafluoroethylene hollow fiber membrane (PTFE hydrophobic membrane), which has strong resistance to chemical corrosion, oxidation, and thermal stability, while also possessing a low coefficient of friction and good hydrophobicity. The inlet component 110 and the outlet component 120 are connected via a circulation pipe 200, which is connected to a circulation pump 240. The circulation pump 240 drives the wastewater to circulate in the circulation pipe 200 for membrane distillation. In some embodiments, the circulation pump 240 is a peristaltic pump. The distillation vapor outlet 130 is connected to the condenser 300.

[0027] The oxidant addition device 400 is connected to the inlet water component 110, and is used to add persulfate and percarbonate. A catalyst is loaded on the inner surface of the hollow fiber membrane 140. The catalyst includes manganese oxide.

[0028] It also includes a sulfate ion monitor 210 and a first water quality detector 220, both of which are installed on the circulation pipe 200, which has a recovery outlet 230. When the sulfate ion monitor 210 detects that the sulfate ion concentration in the circulation pipe 200 is higher than a threshold, it stops inputting new wastewater into the inlet component 110, and the original wastewater continues to circulate and be purified until the first water quality detector 220 detects that the water quality meets the standard. Then, the recovery outlet 230 is opened to discharge the water. The treated water with excessively high sulfate ion concentration is discharged for sulfate ion recovery and reuse. In some embodiments, the first water quality detector 220 is a water quality EDC-UV detector.

[0029] It also includes a temperature monitoring sensor component 700, which is located at the water inlet component 110. The temperature of the dry gas (dry air or nitrogen) blown out in the stripping mechanism is adjusted according to the temperature monitored by the temperature monitoring sensor component 700. This reduces the probability of recalcitrant organic pollutants volatilizing through the hollow fiber membrane 140.

[0030] The working principle of the waste heat-driven membrane distillation water purification device in this embodiment is as follows: During water purification, high-heat wastewater is introduced into the membrane distillation reactor 100 from the inlet component 110. In some embodiments, the wastewater can also be heated by means of electric heating wire, solar energy, industrial cooling water waste heat, or low-grade heat energy before treatment. The temperature of the high-heat wastewater is 60-90℃. Persulfate and percarbonate are added simultaneously through the oxidant addition device 400. The high-heat wastewater, persulfate, and percarbonate flow together inside the hollow fiber membrane 140. The high-temperature thermal activation of the high-heat wastewater itself activates the persulfate and percarbonate, degrading the recalcitrant organic pollutants in the wastewater. The thermal activation mechanism of persulfate is as follows: The thermal activation mechanism of percarbonate is as follows: , Simultaneously, the catalyst supported on the membrane synergistically degrades pollutants in the water, reducing pollutant deposition on the membrane surface and improving membrane distillation purification efficiency. Under the high temperature of the high-heat wastewater, water vapor, driven by the vapor pressure difference generated by the temperature difference between the inside and outside of the membrane, permeates through the hydrophobic hollow fiber membrane 140, enters the outer side of the membrane, and enters the condenser 300 from the distillation steam outlet 130 for condensation. Undegraded organic matter and sulfate ions and other impurities generated by the oxidation of sulfate free radicals cannot permeate the hydrophobic membrane. The remaining wastewater enters the circulation pipe 200 through the effluent component 120, and then re-enters the membrane distillation reactor 100 from the influent component 110 for membrane distillation. By utilizing the industrial waste heat of the high-heat wastewater to activate disulfate and percarbonate to degrade recalcitrant organic matter in the wastewater, and simultaneously using the catalyst supported on the membrane to synergistically degrade pollutants in the water, the membrane distillation purification efficiency is improved.

[0031] Example 2 This embodiment is the second embodiment of the waste heat driven membrane distillation water purification device. This embodiment is similar to the first embodiment, except that in this embodiment, a comparative experiment on the degradation efficiency of different degradation methods is conducted.

[0032] Wastewater with BPA concentration of 3 mg / L and pH of 6.5 was selected as the treatment target, and BPA concentration was detected using high-performance liquid chromatography (HPLC). BPA, short for Bisphenol A, is an important organic chemical raw material mainly used in the production of polycarbonate plastics and epoxy resins. During the production process, polymerization reactions, equipment cleaning, and product switching all generate wastewater containing unreacted BPA monomers, oligomers, and solvents, with BPA concentrations potentially reaching tens to hundreds of mg / L. The high toxicity, high stability, and poor biodegradability of BPA make it difficult for traditional wastewater treatment methods (such as conventional biological methods) to effectively remove it.

[0033] Experiment 1: SPC (percarbonate) and PDS (persulfate) were added separately at a concentration of 10-100 mg / L, and the reaction time was 120 min; Experiment 2: SPC (percarbonate) and PDS (persulfate) were added at concentrations of 10-100 mg / L, and MnO was loaded onto the inner surface of the hollow fiber membrane at a concentration of 1.2 mg / L. x The reaction time is 120 min; Experiment 3: SPC (percarbonate) and PDS (persulfate) were added at concentrations of 10-100 mg / L, and MnO was loaded onto the inner surface of the hollow fiber membrane at a concentration of 1.2 mg / L. x UV activation was performed using a 15W UVC lamp for 120 minutes. Experiment 4: SPC (percarbonate) and PDS (persulfate) were added at concentrations of 10-100 mg / L, and 1.2 mg / L MnO was loaded onto the inner surface of the hollow fiber membrane 140. x Electrode activation was performed using stainless steel electrodes, with a reaction time of 120 min. Experiment 5: SPC (percarbonate) and PDS (persulfate) were added at concentrations of 10-100 mg / L, and 1.2 mg / L MnO was loaded onto the inner surface of the hollow fiber membrane 140. x The wastewater is heated for thermal activation.

[0034] like Figure 2 As shown, the BPA degradation efficiencies were 12.5%, 13.1%, 55.7%, 68.4%, and 98.7%, respectively. The effluent quality of Experiment 5 was as follows: conductivity <15 µS / cm, total dissolved solids <10 mg / L, ion removal rate >99%, non-volatile substances >99.99%; the total organic carbon (TOC) in the final effluent was <500 μg / L, meeting stringent wastewater reuse standards for municipal reuse or roadside greening irrigation.

[0035] Example 3 This embodiment is the third embodiment of a waste heat-driven membrane distillation water purification device. This embodiment is similar to Embodiment 1, except that, as shown in the following... Figure 3 As shown, the system also includes a pH detection device 500 and a control system 600. The pH detection device 500 is located at the water inlet component 110. Both the pH detection device 500 and the oxidant addition device 400 are electrically connected to the control system 600. The control system 600 controls the oxidant addition device 400 to adjust the addition ratio of persulfate and percarbonate based on the pH value detected by the pH detection device 500. By adjusting the addition ratio of persulfate and percarbonate according to the pH value detected by the pH detection device 500, the degradation efficiency across the entire pH range is improved.

[0036] When the pH detection device 500 detects a pH value less than 7, the ratio of persulfate to percarbonate added is greater than 1; when the pH detection device 500 detects a pH value equal to 7, the ratio of persulfate to percarbonate added is 1; when the pH detection device 500 detects a pH value greater than 7, the ratio of persulfate to percarbonate added is less than 1.

[0037] Specifically, the dosage of persulfate and percarbonate is related to the pH value as follows:

[0038]

[0039] In the formula, This indicates the mass percentage of persulfate in the total mass of persulfate and percarbonate; This indicates the mass percentage of percarbonate in the total mass of perisosulfate and percarbonate; This indicates the pH value.

[0040] In some embodiments, such as Figure 4 As shown, high-concentration BPA was selected as the wastewater to be treated. The wastewater quality parameters were: COD = 1500-2000 mg / L, pH = 3-12. The dosage and ratio of oxidant were based on the influent COD concentration and added according to the stoichiometric ratio (PDS / SPC concentration: COD concentration = 0.2-10). The oxidant concentration was approximately 15-20 g / L. The dosage ratio of PDS and SPC was adjusted by detecting the pH of the wastewater influent. The pollutant removal rate was dynamically adjusted under different pH conditions for PDS alone, SPC alone, and the combined use of SPC / PDS. The reaction time was 120 min, and the reaction temperature was T=60℃. After the reaction, the remaining BPA concentration was measured using high-performance liquid chromatography (HPLC). The pollutant degradation efficiency results for the three methods of PDS alone, SPC alone, and the combined use of SPC / PDS are shown in the figure. When using PDS alone, the treatment efficiency was high under acidic conditions, all above 82.1%. However, at pH ≥ 8, the degradation rate dropped sharply to below 60.6%. This is because PDS at acidic to neutral conditions (pH 3-7) has a high efficiency for SO4• - As the dominant free radical, SO4• is highly efficient and stable, but under alkaline conditions (pH>8), it... - It is quenched and transformed into weakly potent •OH and O2•. -The efficiency drops sharply. Similarly, when SPC is used alone as an oxidant, its degradation efficiency is high, exceeding 80.5%, at pH 6-11. This is because SPC's buffering effect makes it stable and efficient in weakly alkaline environments. However, outside this range, its degradation rate drops sharply, similar to PDS. This is because the SPC system is unstable and easily decomposes H2O2 in acidic conditions (pH 3-5), and •OH is quenched, resulting in low efficiency. Once the pH exceeds 11, the self-decomposition of H2O2 intensifies, further reducing efficiency. However, by dynamically adjusting the SPC / PDS dosage according to the influent pH, the degradation efficiency across the entire pH range can be significantly improved by adjusting the ratio of the two dosages under different pH conditions. It maintains a high degradation efficiency (82.4%) at pH 3-12.

[0041] In some embodiments, the control system 600 can also monitor the influent water quality in real time using water quality and temperature monitors. When the concentration of recalcitrant organic matter in the water is high, exceeding the standard value, the dosage of the reagent will be adjusted to achieve higher pollutant degradation efficiency. Typically, the ratio of influent flow rate to reagent dosage is increased. Generally, the ratio of oxidant dosage to wastewater COD is 0.5-10:1. When the concentration of recalcitrant organic matter in the influent is too high, the reagent dosage ratio will be increased, thereby increasing the reagent dosage to improve pollutant degradation efficiency. If the control system 600 detects a decrease in influent water temperature, when the temperature decreases (the optimal temperature is 70°C), the oxidation rates of SPC and PDS will decrease. In this case, it is necessary to increase the system circulation frequency to increase the reaction time and improve pollutant degradation efficiency.

[0042] Example 4 This embodiment is the fourth embodiment of a waste heat-driven membrane distillation water purification device. This embodiment is similar to Embodiment 1, except that, as shown in the following... Figure 5 As shown, the system also includes a second water quality detector 800 and an ozone reactor 900. The condenser 300 is connected to the inlet of the second water quality detector 800. The second water quality detector 800 has a first outlet 810 and a second outlet 820, with the second outlet 820 connected to the ozone reactor 900. When the industrial wastewater contains highly volatile pollutants, or when the wastewater temperature is high enough to make the pollutants easily volatilize, the second water quality detector 800 monitors that the water condensed by the condenser 300 does not meet the effluent quality standards and has an excessively high organic matter concentration. The water is then discharged through the second outlet 820 to the ozone reactor 900 for secondary treatment.

[0043] The ozone reactor 900 includes a reaction tank 910, an ozone aeration device 920, an aeration pump 930, and an ozone generator 940. A second outlet 820 is connected to the reaction tank 910. The ozone generator 940, aeration pump 930, ozone aeration device 920, and reaction tank 910 are connected in sequence. The ozone generator 940 generates ozone, which enters the ozone aeration device 920 through the aeration pump 930, and then enters the reaction tank 910 to aerate the water. The reaction tank 910 has a third outlet from which the purified water is discharged. In some embodiments, a third water quality detector may be added to the third outlet to detect the water quality after aeration.

[0044] In some embodiments, the ozone aeration device 920 may be equipped with a power regulator to adjust the ozone concentration by controlling the power.

[0045] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0046] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A waste heat-driven membrane distillation water purification device, characterized in that, The device includes a membrane distillation reactor (100), a circulation pipe (200), a condenser (300), and an oxidant addition device (400). The membrane distillation reactor (100) is provided with a water inlet (110), a water outlet (120), and a distillation steam outlet (130). The water inlet (110) and the water outlet (120) are connected through the circulation pipe (200), and the distillation steam outlet (130) is connected to the condenser (300). The oxidant addition device (400) is connected to the water inlet (110) and is used to add persulfate and percarbonate. The membrane distillation reactor (100) is provided with a plurality of hollow fiber membranes (140), and the inner surface of the hollow fiber membranes (140) is loaded with a catalyst.

2. The waste heat-driven membrane distillation water purification device according to claim 1, characterized in that, It also includes a pH detection device (500) and a control system (600). The pH detection device (500) is located at the water inlet component (110). The pH detection device (500) and the oxidant addition device (400) are both electrically connected to the control system (600). The control system (600) controls the oxidant addition device (400) to adjust the addition ratio of persulfate and percarbonate according to the pH value detected by the pH detection device (500).

3. The waste heat-driven membrane distillation water purification device according to claim 2, characterized in that, When the pH detection device (500) detects a pH value less than 7, the addition ratio of persulfate to percarbonate is greater than 1; when the pH detection device (500) detects a pH value equal to 7, the addition ratio of persulfate to percarbonate is 1; when the pH detection device (500) detects a pH value greater than 7, the addition ratio of persulfate to percarbonate is less than 1.

4. The waste heat-driven membrane distillation water purification device according to claim 2, characterized in that, The added mass of persulfate and percarbonate satisfies the following relationship with the pH value: In the formula, This indicates the mass percentage of persulfate in the total mass of persulfate and percarbonate; This indicates the mass percentage of percarbonate in the total mass of perisosulfate and percarbonate; This indicates the pH value.

5. The waste heat-driven membrane distillation water purification device according to claim 1, characterized in that, The catalyst includes manganese oxide.

6. The waste heat-driven membrane distillation water purification device according to claim 1, characterized in that, It also includes a sulfate ion monitor (210) and a first water quality detector (220), both of which are installed on the circulation pipe (200), and the circulation pipe (200) is provided with a recovery outlet (230); when the sulfate ion monitor (210) detects that the sulfate ion concentration in the circulation pipe (200) is higher than the threshold, it stops inputting new wastewater into the inlet component (110), and the original wastewater continues to circulate and be purified until the first water quality detector (220) detects that the water quality meets the standard, and then the recovery outlet (230) is opened to discharge the water.

7. The waste heat-driven membrane distillation water purification device according to claim 1, characterized in that, It also includes a temperature monitoring and sensing component (700), which is located at the water inlet component (110), and a stripping mechanism is provided in the membrane distillation reactor (100); the temperature of the dry gas blown out in the stripping mechanism is adjusted according to the temperature monitored by the temperature monitoring and sensing component (700).

8. The waste heat-driven membrane distillation water purification device according to claim 1, characterized in that, The hollow fiber membrane (140) is any one of polypropylene membrane, polyvinylidene fluoride membrane, hydrophobically modified ceramic membrane, and polytetrafluoroethylene membrane.

9. The waste heat-driven membrane distillation water purification device according to any one of claims 1 to 8, characterized in that, It also includes a second water quality detector (800) and an ozone reactor (900), the condenser (300) being connected to the inlet of the second water quality detector (800), the second water quality detector (800) having a first outlet (810) and a second outlet (820), the second outlet (820) being connected to the ozone reactor (900).

10. The waste heat-driven membrane distillation water purification device according to claim 9, characterized in that, The ozone reactor (900) includes a reaction tank (910), an ozone aeration device (920), an aeration pump (930), and an ozone generator (940). The second outlet (820) is connected to the reaction tank (910), and the ozone generator (940), the aeration pump (930), the ozone aeration device (920), and the reaction tank (910) are connected in sequence.

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