A process for treating high-salt wastewater based on membrane filtration and ionization oxidation

Abstract

The present invention discloses a process for treating high-salt wastewater based on membrane filtration and ionization oxidation, belonging to the technical field of wastewater treatment, which includes: S1, intercepting large particulate suspensions and insoluble suspensions in high-salt wastewater in sequence through a filter screen and a solid-liquid separation channel; S2, oxidizing the organic matter in high-salt wastewater through ionization oxidation, sedimenting the inorganic suspensions generated by ionization oxidation with a flocculant, and then intercepting the precipitate through an ionization channel; S3, separating out inorganic salts through evaporation crystallization; S4, separating the inorganic salt crystals and high-salt wastewater through an ultrafiltration membrane filter, and subjecting the separated high-salt wastewater to evaporation crystallization again. By repeatedly performing evaporation crystallization on high-salt wastewater, the present invention increases the recovery efficiency of inorganic salts in high-salt wastewater, and at the same time purifies and recovers the wastewater, which can effectively save water resources and improve the economic benefits of high-salt wastewater treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and specifically relates to a process for treating high-salt wastewater based on membrane filtration and ionization oxidation. Background Technique

[0002] High-salt wastewater refers to wastewater with a total salt content of at least 3.5 wt%, mainly originating from industrial production processes such as chemical plants, oil and natural gas collection and processing. This type of wastewater contains various substances, including salts, oils, organic heavy metals, and radioactive substances, etc. Due to its high salt content, it poses a serious threat to the environment and ecology. Therefore, the treatment of high-salt wastewater has become an important topic in environmental protection and sustainable resource utilization.

[0003] The main salt substances in high-salt wastewater include Cl - , SO4 2- , Na + , Ca 2+ etc. Although these ions are beneficial to the growth of microorganisms at a certain concentration, when the concentration is too high, they will have an inhibitory and toxic effect on microorganisms, affecting their treatment efficiency. In addition, there are various types of organic substances in high-salt wastewater, and the biochemical treatment is difficult. Traditional biological treatment methods often fail to work.

[0004] Existing high-salt wastewater treatment processes mostly precipitate inorganic salts through evaporation crystallization and membrane filtration technologies and then perform solid-liquid separation. However, the organic matter content in the wastewater is large and difficult to treat, and it causes the precipitated inorganic salts to be contaminated, reducing the economic value of the recycled inorganic salts. The existing treatment of high-salt wastewater often requires rotation and residence in multiple devices, and cannot continuously treat high-salt wastewater, resulting in low treatment efficiency of high-salt wastewater. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a process for treating high-salt wastewater based on membrane filtration and ionization oxidation.

[0006] The technical solution of the present invention is: a process for treating high-salt wastewater based on membrane filtration and ionization oxidation, including the following steps:

[0007] S1. Pretreatment:

[0008] Pass the high-salt wastewater into a pretreatment device for filtration through a filter screen. The mesh number of the filter screen is 10 - 14 meshes. Then, pass the filtered high-salt wastewater through the solid-liquid separation channel in the pretreatment device to remove the suspended particles in the high-salt wastewater. The flow rate of the wastewater in the solid-liquid separation channel is 4.5 - 6 L / min to obtain pretreated high-salt wastewater;

[0009] S2. Ionization Oxidation:

[0010] The pretreated high-salt wastewater is introduced from the pretreatment equipment into multiple ionization precipitation devices for ionization oxidation treatment. A flocculant is added into the ionization channel 21, and the addition amount of the flocculant is 50 mg / L. Then, the precipitate and the wastewater are separated by solid-liquid separation through the ionization channel in the ionization precipitation device. The width of the ionization channel is 5 - 10 cm. The anode in the ionization channel is made of carbon plate, and the cathode is made of stainless steel plate. The ionization voltage is 5 V, and the current density is 50 - 80 A / m 2 , and the flow rate of the pretreated high-salt wastewater in the ionization channel is 4.5 - 6 L / min to obtain oxidized wastewater;

[0011] S3. Evaporation and crystallization:

[0012] The oxidized wastewater is introduced into the evaporation channel in multiple evaporation crystallization devices for evaporation. The evaporation temperature is 50 - 60 °C, the evaporation duration is 20 - 30 min, and the flow rate of the evaporation channel is 4.5 - 6 L / min. After the water molecules in the wastewater evaporate, inorganic salts precipitate to form crystals and form crystal salt wastewater with the remaining wastewater;

[0013] S4. Membrane filtration:

[0014] The crystal salt wastewater is introduced into an ultrafiltration membrane filter for filtration. After filtration, the inorganic salt crystals are recovered. The average pore size of the ultrafiltration membrane is 5 - 10 nm, and the high-salt wastewater filtered by the ultrafiltration membrane filter is secondarily evaporated through the evaporation crystallization device.

[0015] Furthermore, the equipment used in the process for treating high-salt wastewater based on membrane filtration and ionization oxidation includes a pretreatment equipment, an ionization precipitation equipment, an evaporation crystallization equipment, and an ultrafiltration membrane filter. The pretreatment equipment includes a filtration tank, on which a filter screen is fixedly connected. On the right side of the filtration tank, multiple solid-liquid separation channels are fixedly connected. Below the solid-liquid separation channels, multiple first sedimentation tanks are fixedly connected in a communicating way. A valve one is fixedly connected to the bottom of the first sedimentation tank. The right ends of the multiple solid-liquid separation channels communicate with a first temporary storage tank.

[0016] Note: The large suspended solids in the high-salt wastewater are filtered through the filter screen, and then the insoluble suspended solids in the high-salt wastewater are intercepted by the first sedimentation tank.

[0017] Furthermore, the ionization precipitation equipment includes an ionization channel. An anode plate and a cathode plate are respectively fixedly connected to the front inner wall and the rear inner wall of the ionization channel. A flocculant feeder is fixedly connected above the left end of the ionization channel. Multiple second sedimentation tanks are fixedly connected to the bottom of the ionization channel. A valve two is fixedly connected to the bottom of the second sedimentation tank. A second temporary storage tank is fixedly connected to the right side of the ionization channel. A liquid extraction pump is fixedly connected inside the second temporary storage tank. The water outlet of the liquid extraction pump is fixedly communicated with a water extraction pipe for communicating with the evaporation crystallization equipment.

[0018] Description: The organic matter in the high-salt wastewater is ionized and oxidized through the ionization channel, and the insoluble inorganic precipitate generated by the ionization oxidation is intercepted by the second sedimentation tank.

[0019] Furthermore, the flocculant feeder includes a silo, and a spiral feeding rod is rotatably connected inside the silo. A feeding motor for driving the spiral feeding rod to rotate is fixedly connected to the top of the silo.

[0020] Description: The flocculant is automatically fed through the feeding motor, and the feeding speed can be changed by adjusting the rotation speed of the feeding motor.

[0021] Furthermore, a first battery panel for supplying power to the anode plate and the cathode plate and a first solar power generation panel for charging the first battery panel are fixedly connected to the top of the ionization channel.

[0022] Description: The first solar power generation panel provides electrical energy to the anode plate and the cathode plate in the ionization channel, forming an electric field between the anode plate and the cathode plate, so that the organic matter undergoes an oxidation reaction at the anode and a reduction reaction at the cathode.

[0023] Furthermore, the evaporation and crystallization device includes an evaporation channel, a condensation channel is fixedly connected to the top of the evaporation channel, an electric heating plate is fixedly connected to the inner bottom of the evaporation channel, a second battery panel for supplying power to the electric heating plate and a second solar power generation panel for charging the second battery panel are fixedly connected to the top of the condensation channel, a condensate channel is fixedly connected inside the evaporation channel, a condensate pool is fixedly connected and communicated to the right side of the condensate channel, and the right side of the evaporation channel is fixedly connected and communicated to the ultrafiltration membrane filter.

[0024] Description: Using solar energy to provide electrical energy to heat the wastewater, increasing the evaporation amount of the wastewater, reducing the electrical energy used for wastewater treatment, and reducing the cost of wastewater treatment.

[0025] Furthermore, the condensation channel includes an intermediate channel, the left side of the intermediate channel is fixedly connected and communicated to the water suction pipe, return channels are fixedly connected to the front and back sides of the intermediate channel, the right end of the return channel is connected and communicated to the intermediate channel, and the left end of the return channel discharges the wastewater into the evaporation channel.

[0026] Description: The evaporated water meets the condensation channel, transfers heat to the wastewater in the condensation channel, and then condenses and falls into the condensate channel, which can enhance the condensation effect and recycle the heat of the evaporated water.

[0027] Further, the ultrafiltration membrane filter includes a filtrate pool, a filter rack is fixedly connected inside the filtrate pool, a plurality of branch pipes are fixedly connected to the filter rack, a connecting pipe is fixedly communicated with the left ends of the plurality of branch pipes, a main pipe is fixedly communicated with the right ends of the plurality of branch pipes, a liquid suction pump is fixedly communicated with the main pipe, a return pipe is fixedly communicated with the water outlet of the liquid suction pump, the return pipe is fixedly communicated with the water extraction pipe, and an ultrafiltration membrane module is fixedly communicated below the branch pipe.

[0028] Description: The waste water is filtered again by the ultrafiltration membrane filter, the precipitated inorganic salts are recovered, and the obtained high-salt waste water is subjected to evaporation crystallization again, increasing the recovery efficiency of the salts in the high-salt waste water and improving the economic benefits of high-salt waste water treatment.

[0029] Further, the ultrafiltration membrane module includes a connection cover, a plurality of ultrafiltration membrane tubes are fixedly connected to the lower end of the connection cover, and the upper part of the connection cover is threadedly connected to the branch pipe.

[0030] Description: The connection cover facilitates the replacement of the ultrafiltration membrane tubes and is convenient for maintenance.

[0031] Further, the flocculant is composed of the following components by mass percentage: 25.1-30.2% polyferric sulfate, 15.4-23.5% sodium polyacrylate, 13.6-18.7% ferrous sulfate, 11.2-15.5% powdered activated carbon, and the balance is water-soluble starch.

[0032] Description: The above flocculant has good flocculation effect, can effectively remove the suspended solids in the oxidized waste water, and increase the cleanliness of the salts after evaporation crystallization.

[0033] The beneficial effects of the present invention are:

[0034] (1) In the present invention, the suspended solids and large suspended solids contained in the high-salt waste water are filtered through pretreatment, then the organic matter in the high-salt waste water is oxidized by the ionization oxidation technology, and then the suspended solids generated by the ionization oxidation are flocculated and precipitated. Finally, inorganic salts are precipitated by evaporation crystallization, and the evaporated water is recycled. The inorganic salts and high-salt waste water are separated by the ultrafiltration membrane filter. By repeatedly evaporating and crystallizing the high-salt waste water, the recovery efficiency of the inorganic salts in the high-salt waste water is increased, and at the same time, the waste water is purified and recycled, which can effectively save water resources and increase the economic benefits of high-salt waste water treatment.

[0035] (2) In the present invention, both the ionization oxidation equipment and the evaporation crystallization equipment use solar panels to provide electric energy, which can effectively reduce the treatment cost of high-salt waste water. The present invention can continuously treat high-salt waste water through the solid-liquid separation channel, the ionization channel and the evaporation crystallization channel, avoiding the time used for static precipitation and the time used for static ionization, and improving the treatment efficiency of high-salt waste water. Description of the Drawings

[0036] Figure 1 It is a schematic structural diagram of the process of the present invention.

[0037] Figure 2 is Figure 1 an enlarged view of part A in

[0038] Figure 3 It is the front view of the pretreatment device of the present invention.

[0039] Figure 4 It is the front view of the ionization precipitation device of the present invention.

[0040] Figure 5 is Figure 4 the sectional view taken along line A-A in

[0041] Figure 6 It is the front view of the evaporation crystallization device and the ultrafiltration membrane filter of the present invention.

[0042] Figure 7 It is the top view of the condensation channel of the present invention.

[0043] Figure 8 It is the sectional view of the condensation channel of the present invention.

[0044] Figure 9 It is the front view of the ultrafiltration membrane module of the present invention.

[0045] Among them, 1 - pretreatment device, 2 - ionization precipitation device, 3 - evaporation crystallization device, 4 - ultrafiltration membrane filter, 11 - filtration tank, 12 - filter screen, 13 - solid-liquid separation channel, 14 - sedimentation tank 1, 15 - valve 1, 16 - temporary storage tank 1, 21 - ionization channel, 22 - anode plate, 23 - cathode plate, 24 - feeder, 25 - sedimentation tank 2, 26 - valve 2, 27 - temporary storage tank 2, 28 - liquid extraction pump, 29 - water extraction pipe, 241 - feed bin, 242 - spiral feeding rod, 243 - feeding motor, 211 - battery panel 1, 212 - solar power generation panel 1, 31 - evaporation channel, 32 - condensation channel, 33 - electric heating plate, 34 - battery panel 2, 35 - solar power generation panel 2, 36 - condensate channel, 37 - condensate pool, 321 - intermediate channel, 322 - return channel, 41 - filtrate pool, 42 - filter rack, 43 - branch pipe, 44 - connecting pipe, 45 - main pipeline, 46 - return pipe, 47 - ultrafiltration membrane module, 48 - liquid suction pump, 471 - connecting cover, 472 - ultrafiltration membrane tube. Detailed implementation manners

[0046] Example 1:

[0047] The high-salt wastewater referred to in the present invention means wastewater with a salt content greater than 3.5 wt%, and the main salt substances in the high-salt wastewater include Cl- 、SO4 2- 、Na + 、Ca 2+ , mainly derived from the wastewater generated in industrial production processes such as chemical plants, oil and gas collection and processing.

[0048] As Figure 1 shown, a process for treating high-salt wastewater based on membrane filtration and ionization oxidation includes the following steps:

[0049] S1. Pretreatment:

[0050] The high-salt wastewater is passed into the pretreatment device 1 and filtered through the filter screen 12. The mesh number of the filter screen 12 is 10 mesh. Then, the filtered high-salt wastewater removes the suspended particles in the high-salt wastewater through the solid-liquid separation channel 13 in the pretreatment device 1. The flow rate of the wastewater in the solid-liquid separation channel 13 is 4.5 L / min, and the pretreated high-salt wastewater is obtained.

[0051] S2. Ionization oxidation:

[0052] The pretreated high-salt wastewater is passed from the pretreatment device 1 into multiple ionization precipitation devices 2 for ionization oxidation treatment. A flocculant is added in the ionization channel, and the addition amount of the flocculant is 50 mg / L. Then, the precipitate and the wastewater are separated by solid-liquid separation through the ionization channel 21 in the ionization precipitation device 2. The width of the ionization channel 21 is 5 cm. The anode in the ionization channel 21 uses a carbon plate, and the cathode uses a stainless steel plate. The ionization voltage is 5 V, and the current density is 50 A / m 2 . The flow rate of the pretreated high-salt wastewater in the ionization channel 21 is 4.5 L / min, and the oxidized wastewater is obtained.

[0053] The flocculant is composed of the following components by mass percentage: 25.1% polyferric sulfate, 15.4% sodium polyacrylate, 13.6% ferrous sulfate, 11.2% powdered activated carbon, and the balance is water-soluble starch;

[0054] S3. Evaporation crystallization:

[0055] The oxidized wastewater is passed into the evaporation channel 31 in multiple evaporation crystallization devices 3 for evaporation. The evaporation temperature is 50 °C, the evaporation duration is 20 min, and the flow rate of the evaporation channel 31 is 4.5 L / min. After the water molecules in the wastewater evaporate, inorganic salts precipitate, forming crystals and crystal salt wastewater with the remaining wastewater;

[0056] S4. Membrane filtration:

[0057] The crystallized salt wastewater is passed through the ultrafiltration membrane filter 4 for filtration. After the filtration is completed, the inorganic salt crystals are recovered. The average pore size of the ultrafiltration membrane is 5 nm. The high-salt wastewater filtered by the ultrafiltration membrane filter 4 is secondarily evaporated in the evaporation crystallization device 3.

[0058] Example 2:

[0059] A process for treating high-salt wastewater based on membrane filtration and ionization oxidation includes the following steps:

[0060] S1. Pretreatment:

[0061] The high-salt wastewater is passed through the pretreatment device 1 and filtered through the filter screen 12. The mesh number of the filter screen 12 is 12 meshes. Then, the filtered high-salt wastewater removes the suspended particles in the high-salt wastewater through the solid-liquid separation channel 13 in the pretreatment device 1. The flow rate of the wastewater in the solid-liquid separation channel 13 is 5 L / min, and the pretreated high-salt wastewater is obtained.

[0062] S2. Ionization oxidation:

[0063] The pretreated high-salt wastewater is passed from the pretreatment device 1 into multiple ionization precipitation devices 2 for ionization oxidation treatment. A flocculant is added in the ionization channel, and the addition amount of the flocculant is 50 mg / L. Then, the precipitate and the wastewater are separated by solid-liquid separation through the ionization channel 21 in the ionization precipitation device 2. The width of the ionization channel 21 is 8 cm. The anode in the ionization channel 21 is made of carbon plate, and the cathode is made of stainless steel plate. The ionization voltage is 5 V, and the current density is 77 A / m 2 , and the flow rate of the pretreated high-salt wastewater in the ionization channel 21 is 5 L / min, and the oxidized wastewater is obtained.

[0064] The flocculant is composed of the following components by mass percentage: 28.2% polyferric sulfate, 20.4% sodium polyacrylate, 15.3% ferrous sulfate, 12.5% powdered activated carbon, and the balance is water-soluble starch;

[0065] S3. Evaporation crystallization:

[0066] The oxidized wastewater is passed into the evaporation channel 31 in multiple evaporation crystallization devices 3 for evaporation. The evaporation temperature is 55 °C, the evaporation duration is 25 min, and the flow rate of the evaporation channel 31 is 56 L / min. After the water molecules in the wastewater evaporate, the inorganic salts precipitate, forming crystals and the remaining wastewater forms crystallized salt wastewater;

[0067] S4. Membrane filtration:

[0068] The crystallized salt wastewater is passed through the ultrafiltration membrane filter 4 for filtration. After filtration is completed, the inorganic salt crystals are recovered. The average pore size of the ultrafiltration membrane is 8 nm. The high-salt wastewater filtered by the ultrafiltration membrane filter 4 is secondarily evaporated in the evaporation crystallization device 3.

[0069] Example 3:

[0070] A process for treating high-salt wastewater based on membrane filtration and ionization oxidation includes the following steps:

[0071] S1. Pretreatment:

[0072] The high-salt wastewater is passed through the pretreatment device 1 and filtered through the filter screen 12. The mesh number of the filter screen 12 is 14 mesh. Then, the filtered high-salt wastewater passes through the solid-liquid separation channel 13 in the pretreatment device 1 to remove the suspended particles in the high-salt wastewater. The flow rate of the wastewater in the solid-liquid separation channel 13 is 6 L / min, and the pretreated high-salt wastewater is obtained.

[0073] S2. Ionization oxidation:

[0074] The pretreated high-salt wastewater is passed from the pretreatment device 1 into multiple ionization precipitation devices 2 for ionization oxidation treatment. A flocculant is added in the ionization channel. The addition amount of the flocculant is 50 mg / L. Then, the precipitate and the wastewater are separated by solid-liquid separation through the ionization channel 21 in the ionization precipitation device 2. The width of the ionization channel 21 is 10 cm. The anode in the ionization channel 21 is made of carbon plate, and the cathode is made of stainless steel plate. The ionization voltage is 5 V, and the current density is 80 A / m 2 , and the flow rate of the pretreated high-salt wastewater in the ionization channel 21 is 6 L / min, and the oxidized wastewater is obtained.

[0075] The flocculant is composed of the following components by mass percentage: 30.2% polyferric sulfate, 23.5% sodium polyacrylate, 18.7% ferrous sulfate, 15.5% powdered activated carbon, and the balance is water-soluble starch;

[0076] S3. Evaporation crystallization:

[0077] The oxidized wastewater is passed into the evaporation channel 31 in multiple evaporation crystallization devices 3 for evaporation. The evaporation temperature is 60 °C, the evaporation duration is 30 min, and the flow rate of the evaporation channel 31 is 6 L / min. After the water molecules in the wastewater evaporate, inorganic salts precipitate, forming crystals and crystallized salt wastewater with the remaining wastewater;

[0078] S4. Membrane filtration:

[0079] The crystallized salt wastewater is passed through the ultrafiltration membrane filter 4 for filtration. After the filtration is completed, the inorganic salt crystals are recovered. The average pore size of the ultrafiltration membrane is 10 nm. The high-salt wastewater filtered by the ultrafiltration membrane filter 4 is subjected to secondary evaporation in the evaporation crystallization device 3.

[0080] Comparing Example 1 - Example 3, Example 3 has the highest recovery efficiency for high-salt wastewater. Therefore, Example 3 is the best example.

[0081] Example 4:

[0082] This example describes the equipment used in a process for treating high-salt wastewater based on membrane filtration and ionization oxidation in Example 3, including a pretreatment device 1, an ionization precipitation device 2, an evaporation crystallization device 3, and an ultrafiltration membrane filter 4. As Figure 3 shown, the pretreatment device 1 includes a filtration tank 11, on which a filter screen 12 is fixedly connected. On the right side of the filtration tank 11, a plurality of solid-liquid separation channels 13 are fixedly connected. Below the solid-liquid separation channels 13, a plurality of first sedimentation tanks 14 are fixedly connected in communication. At the bottom of the first sedimentation tanks 14, a valve 15 is fixedly connected. The right ends of the plurality of solid-liquid separation channels 13 are communicated with a temporary storage tank 16. The large suspended solids in the high-salt wastewater are filtered through the filter screen 11, and then the insoluble suspended solids in the high-salt wastewater are intercepted by the first sedimentation tanks 14.

[0083] Among them, the ionization precipitation device 2, the evaporation crystallization device 3, and the ultrafiltration membrane filter 4 in this example are products of the prior art.

[0084] Example 5:

[0085] The difference between this example and Example 4 is that, as Figure 4 , Figure 5 shown, the ionization precipitation device 2 includes an ionization channel 21. On the front inner wall and the rear inner wall of the ionization channel 21, an anode plate 22 and a cathode plate 23 are respectively fixedly connected. Above the left end of the ionization channel 21, a flocculant feeder 24 is fixedly connected. At the bottom of the ionization channel 21, a plurality of second sedimentation tanks 25 are fixedly connected. At the bottom of the second sedimentation tanks 25, a valve 26 is fixedly connected. On the right side of the ionization channel 21, a temporary storage tank 27 is fixedly connected. Inside the temporary storage tank 27, a liquid extraction pump 28 is fixedly connected. The water outlet of the liquid extraction pump 28 is fixedly communicated with a water extraction pipe 29 for communicating with the evaporation crystallization device 3.

[0086] The flocculant feeder 24 includes a feed bin 241. Inside the feed bin 241, a spiral feeding rod 242 is rotatably connected. At the top of the feed bin 241, a feeding motor 243 for driving the spiral feeding rod 242 to rotate is fixedly connected.

[0087] A battery panel one 211 for supplying power to the anode plate 22 and the cathode plate 23 and a solar power generation panel one 212 for charging the battery panel one 211 are fixedly connected to the top of the ionization channel 21.

[0088] Compared with Example 4, in Example 5, the solar power generation panel one 212 provides electrical energy for the anode plate 22 and the cathode plate 23 in the ionization channel, so that an electric field is formed between the anode plate 22 and the cathode plate 23. As a result, the organic matter undergoes an oxidation reaction at the anode and a reduction reaction at the cathode. The flocculant is automatically fed through the feeding motor 243, and the feeding speed can be changed by adjusting the rotation speed of the feeding motor 243. The organic matter in the high-salt wastewater is ionized and oxidized through the ionization channel 21, and the insoluble inorganic precipitate generated by the ionization and oxidation is intercepted by the sedimentation tank two 25.

[0089] Example 6:

[0090] The difference between this example and Example 5 is that, as Figure 7 、 Figure 8 shown, the evaporation and crystallization device 3 includes an evaporation channel 31. A condensation channel 32 is fixedly connected to the top of the evaporation channel 31. An electric heating plate 33 is fixedly connected to the inner bottom of the evaporation channel 31. A battery panel two 34 for supplying power to the electric heating plate 33 and a solar power generation panel two 35 for charging the battery panel two 34 are fixedly connected to the top of the condensation channel 32. A condensate channel 36 is fixedly connected to the inside of the evaporation channel 31. A condensate pool 37 is fixedly communicated with the right side of the condensate channel 36. The right side of the evaporation channel 31 is fixedly communicated with the ultrafiltration membrane filter 4.

[0091] The condensation channel 32 includes an intermediate channel 321. The left side of the intermediate channel 321 is fixedly communicated with the water suction pipe 29. Return channels 322 are fixedly connected to the front and rear sides of the intermediate channel 321. The right end of the return channel 322 is communicated with the intermediate channel 321, and the left end of the return channel 322 discharges the wastewater into the evaporation channel 31.

[0092] Compared with Example 5, in Example 6, solar energy is used to provide electrical energy to heat the wastewater, increasing the evaporation amount of the wastewater, reducing the electrical energy used for wastewater treatment, and reducing the cost of wastewater treatment. The evaporated water meets the condensation channel 32, transfers the heat to the wastewater in the condensation channel 32, and then condenses and falls into the condensate channel 36, which can enhance the condensation effect and recycle the heat of the evaporated water.

[0093] Example 7:

[0094] The difference between this example and Example 6 is that, as Figure 2 、 Figure 6 、 Figure 9As shown in the figure, the ultrafiltration membrane filter 4 includes a filtrate tank 41, a filter rack 42 is fixedly connected inside the filtrate tank 41, a plurality of branch pipes 43 are fixedly connected to the filter rack 42, a connecting pipe 44 is fixedly communicated with the left ends of the plurality of branch pipes 43, a main pipe 45 is fixedly communicated with the right ends of the plurality of branch pipes 43, a liquid suction pump 48 is fixedly communicated with the main pipe 45, a return pipe 46 is fixedly communicated with the water outlet of the liquid suction pump 48, the return pipe 46 is fixedly communicated with the water extraction pipe 29, and an ultrafiltration membrane module 47 is fixedly communicated below the branch pipe 43.

[0095] The ultrafiltration membrane module 47 includes a connection cover 471, a plurality of ultrafiltration membrane tubes 472 are fixedly connected to the lower end of the connection cover 471, and the upper part of the connection cover 471 is threadedly connected to the branch pipe 43.

[0096] Compared with Embodiment 6, in Embodiment 7, the wastewater is filtered again by the ultrafiltration membrane filter 4, the precipitated inorganic salts are recovered, and the obtained high-salt wastewater is subjected to evaporation crystallization again, so as to increase the recovery efficiency of the salt in the high-salt wastewater and increase the economic benefits of high-salt wastewater treatment. The connection cover 471 facilitates the replacement of the ultrafiltration membrane tube 472 and is convenient for maintenance.

[0097] In the above embodiments, the feeding motor 243, the liquid extraction pump 28, the liquid suction pump 48, the first battery panel 211, the first solar power generation panel 212, the electrolytic heating plate 33, the second battery panel 34, and the second solar power generation panel 212 are all commercially available products. As long as they can achieve the functions of the present invention, those skilled in the art can select and use them according to common sense and no special limitations are made here.

Claims

1. A process for treating high-salt wastewater based on membrane filtration and ionization oxidation, characterized in that, It includes the following steps: S1. Pretreatment: The high-salt wastewater is introduced into the pretreatment device (1) and filtered through the filter screen (12). The mesh number of the filter screen (12) is 10 - 14 meshes. Then, the filtered high-salt wastewater removes the suspended particles in the high-salt wastewater through the solid-liquid separation channel (13) in the pretreatment device (1). The flow rate of the wastewater in the solid-liquid separation channel (13) is 4.5 - 6 L / min, and the pretreated high-salt wastewater is obtained. S2. Ionization oxidation: The pretreated high-salt wastewater is introduced from the pretreatment equipment (1) into multiple ionization precipitation equipment (2) for ionization oxidation treatment. A flocculant is added into the ionization channel (21), and the addition amount of the flocculant is 50 mg / L. Then, the precipitate and the wastewater are subjected to solid-liquid separation through the ionization channel (21) in the ionization precipitation equipment (2). The width of the ionization channel (21) is 5-10 cm. The anode in the ionization channel (21) is made of carbon plate, and the cathode is made of stainless steel plate. The ionization voltage is 5 V, and the current density is 50-80 A / m 2 , and the flow rate of the pretreated high-salt wastewater in the ionization channel (21) is 4.5-6 L / min to obtain oxidized wastewater; S3. Evaporation crystallization: The oxidized wastewater is introduced into the evaporation channel (31) of multiple evaporation crystallization devices (3) for evaporation. The evaporation temperature is 50 - 60 °C, the evaporation duration is 20 - 30 min, and the flow rate of the evaporation channel (31) is 4.5 - 6 L / min. After the water molecules in the wastewater evaporate, inorganic salts precipitate, forming crystals and the remaining wastewater forms crystal salt wastewater. S4. Membrane filtration: The crystal salt wastewater is introduced into the ultrafiltration membrane filter (4) for filtration. After filtration, the inorganic salt crystals are recovered. The average pore size of the ultrafiltration membrane is 5 - 10 nm. The high-salt wastewater filtered by the ultrafiltration membrane filter (4) is secondarily evaporated through the evaporation crystallization device (3). The equipment used in the process for treating high-salt wastewater based on membrane filtration and ionization oxidation includes a pretreatment device (1), an ionization precipitation device (2), an evaporation crystallization device (3), and an ultrafiltration membrane filter (4). The pretreatment device (1) includes a filter tank (11). A filter screen (12) is fixedly connected to the filter tank (11). A plurality of solid-liquid separation channels (13) are fixedly connected to the right side of the filter tank (11). A plurality of sedimentation tanks one (14) are fixedly connected and communicated below the solid-liquid separation channels (13). A valve one (15) is fixedly connected to the bottom of the sedimentation tank one (14). The right ends of the plurality of solid-liquid separation channels (13) are communicated with a temporary storage tank one (16). The ionization precipitation device (2) includes an ionization channel (21). An anode plate (22) and a cathode plate (23) are respectively fixedly connected to the front inner wall and the rear inner wall of the ionization channel (21). A flocculant feeder (24) is fixedly connected above the left end of the ionization channel (21). A plurality of sedimentation tanks two (25) are fixedly connected to the bottom of the ionization channel (21). A valve two (26) is fixedly connected to the bottom of the sedimentation tank two (25). A temporary storage tank two (27) is fixedly connected to the right side of the ionization channel (21). A liquid extraction pump (28) is fixedly connected inside the temporary storage tank two (27). The water outlet of the liquid extraction pump (28) is fixedly communicated with a water extraction pipe (29) for communicating with the evaporation crystallization device (3). The flocculant feeder (24) includes a material bin (241). A spiral feeding rod (242) is rotatably connected inside the material bin (241). A feeding motor (243) for driving the spiral feeding rod (242) to rotate is fixedly connected to the top of the material bin (241). A battery panel one (211) for powering the anode plate (22) and the cathode plate (23) and a solar power generation panel one (212) for charging the battery panel one (211) are fixedly connected to the top of the ionization channel (21).

2. The process for treating high-salt wastewater based on membrane filtration and ionization oxidation as claimed in claim 1, wherein, The evaporation and crystallization device (3) includes an evaporation channel (31). A condensation channel (32) is fixedly connected to the top of the evaporation channel (31). An electric heating plate (33) is fixedly connected to the inner bottom of the evaporation channel (31). A battery panel two (34) for powering the electric heating plate (33) and a solar power generation panel two (35) for charging the battery panel two (34) are fixedly connected to the top of the condensation channel (32). A condensate channel (36) is fixedly connected to the inside of the evaporation channel (31). A condensate pool (37) is fixedly communicated with the right side of the condensate channel (36). The right side of the evaporation channel (31) is fixedly communicated with the ultrafiltration membrane filter (4).

3. The process for treating high-salt wastewater based on membrane filtration and ionization oxidation as described in claim 2, characterized in that, The condensation channel (32) includes an intermediate channel (321). The left side of the intermediate channel (321) is fixedly communicated with the water suction pipe (29). Return channels (322) are fixedly connected to the front and rear sides of the intermediate channel (321). The right end of the return channel (322) is communicated with the intermediate channel (321). The left end of the return channel (322) discharges the waste water into the evaporation channel (31).

4. A process for treating high-salt wastewater based on membrane filtration and ionization oxidation as described in claim 1, characterized in that, The ultrafiltration membrane filter (4) includes a filtrate pool (41). A filter rack (42) is fixedly connected to the inside of the filtrate pool (41). A plurality of branch pipes (43) are fixedly connected to the filter rack (42). A connecting pipe (44) is fixedly communicated with the left ends of the plurality of branch pipes (43). A main pipe (45) is fixedly communicated with the right ends of the plurality of branch pipes (43). A liquid suction pump (48) is fixedly communicated with the main pipe (45). The water outlet of the liquid suction pump (48) is fixedly communicated with a return pipe (46). The return pipe (46) is fixedly communicated with the water suction pipe (29). An ultrafiltration membrane module (47) is fixedly communicated with the lower part of the branch pipe (43).

5. A process for treating high-salt wastewater based on membrane filtration and ionization oxidation as claimed in claim 4, characterized in that, The ultrafiltration membrane module (47) includes a connection cover (471). A plurality of ultrafiltration membrane tubes (472) are fixedly connected to the lower end of the connection cover (471). The upper part of the connection cover (471) is threadedly connected to the branch pipe (43).

6. The process for treating high-salt wastewater based on membrane filtration and ionization oxidation according to claim 4, characterized in that, The ultrafiltration membrane module (47) includes a connection cover (471). A plurality of ultrafiltration membrane tubes (472) are fixedly connected to the lower end of the connection cover (471).

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