Wastewater treatment system

Abstract

The utility model discloses a wastewater treatment system. The wastewater treatment system comprises a wastewater collection pool, the inlet end of the first-stage deslagging module is communicated with the wastewater collecting tank; the inlet end of the COD treatment module is communicated with the outlet end of the primary deslagging module; the inlet end of the secondary deslagging module is communicated with the outlet end of the COD treatment module; the inlet end of the multi-stage wastewater concentration module is communicated with the outlet end of the second-stage deslagging module; the recycling water tank and the crystallization sedimentation tank are respectively communicated with the multi-stage wastewater concentration module, and the crystallization sedimentation tank is connected with a circulating backflow water path communicated with the first-stage deslagging module. According to the wastewater treatment system disclosed by the embodiment of the utility model, suspended solids and impurities in wastewater can be effectively removed, the component proportion of lithium ions in concentrated water can be effectively increased, the recycling rate of water resources can be increased, and zero discharge treatment of the wastewater can be realized.

Description

Technical Field

[0001] This utility model relates to the field of environmental protection technology, and in particular to a wastewater treatment system. Background Technology

[0002] Lithium iron phosphate (LFP) is an important cathode material widely used in lithium-ion batteries. Lithium-ion batteries are high-performance, high-energy-density batteries widely used in mobile phones, laptops, electric vehicles, and other fields.

[0003] It is important to note that environmental protection and safety must be prioritized during the production and processing of lithium iron phosphate materials, especially in wastewater and waste disposal, where strict adherence to relevant environmental regulations and standards is essential. Currently, lithium iron phosphate wastewater is characterized by large volumes and significant fluctuations in water quality. Existing technologies have limited capacity to treat COD (Chemical Oxygen Demand) in this wastewater. Zero-discharge treatment results in excessively low concentration ratios, leading to large volumes of concentrated wastewater. Furthermore, the proportion of lithium ions in the wastewater is low, and the water resource utilization rate after treatment is too low, indicating room for improvement. Utility Model Content

[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a wastewater treatment system that can effectively remove suspended solids and impurities from wastewater, effectively increase the proportion of lithium ions in concentrated wastewater, improve water resource reuse rate, and achieve zero-discharge treatment of wastewater, meeting the requirements of relevant environmental regulations and standards.

[0005] The wastewater treatment system according to an embodiment of the present invention includes: a wastewater collection tank; a primary sludge removal module, the inlet of which is connected to the wastewater collection tank; a COD treatment module, the inlet of which is connected to the outlet of the primary sludge removal module; a secondary sludge removal module, the inlet of which is connected to the outlet of the COD treatment module; a multi-stage wastewater concentration module, the inlet of which is connected to the outlet of the secondary sludge removal module; a recycled water tank and a crystallization sedimentation tank, the recycled water tank and the crystallization sedimentation tank being respectively connected to the multi-stage wastewater concentration module, and the crystallization sedimentation tank being connected to a circulating return water path connected to the primary sludge removal module.

[0006] According to the wastewater treatment system of this utility model embodiment, by performing multi-stage treatment on high-concentration lithium iron phosphate wastewater, suspended solids and impurities in the wastewater can be effectively removed, and the wastewater can be concentrated in multiple stages to effectively increase the proportion of lithium ions in the concentrated water and improve the water resource reuse rate. In addition, the remaining concentrated water in the crystallization sedimentation tank can re-enter the primary slag removal module, which can achieve zero-discharge treatment of wastewater and meet the requirements of relevant environmental protection regulations and standards.

[0007] According to some embodiments of the wastewater treatment system of this utility model, the primary sludge removal module includes a coagulation sedimentation tank and a combined air flotation machine. The inlet end of the coagulation sedimentation tank is connected to the wastewater collection tank, the outlet end of the coagulation sedimentation tank is connected to the inlet end of the combined air flotation machine, the outlet end of the combined air flotation machine is connected to the inlet end of the COD treatment module, and the outlet end of the circulating return water path is connected to the coagulation sedimentation tank.

[0008] According to some embodiments of the wastewater treatment system of this utility model, the COD treatment module includes a catalytic structure and a biochemical treatment structure. The inlet end of the catalytic structure is connected to the outlet end of the primary slag removal module, the outlet end of the catalytic structure is connected to the inlet end of the biochemical treatment structure, and the outlet end of the biochemical treatment structure is connected to the secondary slag removal module.

[0009] According to some embodiments of the wastewater treatment system of this utility model, the catalytic structure includes an XE catalytic structure and a secondary catalytic structure. The inlet end of the XE catalytic structure is connected to the outlet end of the primary slag removal module, the outlet end of the XE catalytic structure is connected to the inlet end of the secondary catalytic structure, and the outlet end of the secondary catalytic structure is connected to the inlet end of the biochemical treatment structure.

[0010] According to some embodiments of the wastewater treatment system of this utility model, an intermediate reflux water path is also connected between the outlet end of the biochemical treatment structure and the inlet end of the XE catalytic structure.

[0011] According to some embodiments of the wastewater treatment system of the present invention, the secondary sludge removal module includes at least one sedimentation structure and at least one filtration module, wherein the at least one sedimentation structure and the at least one filtration module are sequentially connected between the COD treatment module and the multi-stage wastewater concentration module.

[0012] According to some embodiments of the wastewater treatment system of this utility model, the sedimentation structure is a single unit configured as an MBR membrane tank, and the filtration modules are two units configured as a multi-media filter and a ceramic membrane device, respectively. The inlet end of the MBR membrane tank is connected to the outlet end of the COD treatment module, the outlet end of the MBR membrane tank is connected to the inlet end of the multi-media filter, the outlet end of the multi-media filter is connected to the inlet end of the ceramic membrane device, and the outlet end of the ceramic membrane device is connected to the multi-stage wastewater concentration module.

[0013] According to some embodiments of the wastewater treatment system of this utility model, the multi-stage wastewater concentration module includes multiple wastewater concentration structures connected in series; wherein, among the multiple wastewater concentration structures, the upstream wastewater concentration structure is connected to the outlet end of the secondary slag removal module, and the downstream wastewater concentration structure is connected to the recycled water tank and the crystallization sedimentation tank respectively.

[0014] According to some embodiments of the wastewater treatment system of this utility model, the multiple wastewater concentration structures are four in number, namely a primary concentration structure, a secondary concentration structure, a tertiary concentration structure and a high-pressure concentration structure. The primary concentration structure, the secondary concentration structure, the tertiary concentration structure and the high-pressure concentration structure are connected in series, and the primary concentration structure is connected to the recycled water tank through a primary product water flow path.

[0015] According to some embodiments of the wastewater treatment system of this utility model, a first concentrated water return flow path is connected between the outlet end of the three-stage concentration structure and the inlet end of the two-stage concentration structure, and a second concentrated water return flow path is connected between the outlet end of the high-pressure concentration structure and the inlet end of the two-stage concentration structure.

[0016] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0018] Figure 1 This is a schematic diagram of a wastewater treatment system according to an embodiment of the present utility model.

[0019] Figure label:

[0020] Wastewater treatment system 100,

[0021] Wastewater collection tank 1,

[0022] Primary slag removal module 2, coagulation sedimentation tank 21, combined air flotation unit 22,

[0023] COD treatment module 3, catalytic structure 31, XE catalytic structure 311, secondary catalytic structure 312, biochemical treatment structure 32, intermediate reflux water path 321.

[0024] Secondary slag removal module 4, sedimentation structure 41, filtration module 42, multi-media filter 421, ceramic membrane device 422.

[0025] The multi-stage wastewater concentration module 5 includes a primary concentration structure 51, a primary product water flow path 511, a secondary concentration structure 52, a tertiary concentration structure 53, a first concentrate return flow path 531, a high-pressure concentration structure 54, and a second concentrate return flow path 541.

[0026] Reclaimed water tank 6,

[0027] Crystallization sedimentation tank 7, circulating return water path 71. Detailed Implementation

[0028] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0029] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model 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, and therefore should not be construed as a limitation of this utility model. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] The following is for reference. Figure 1 The wastewater treatment system 100 according to an embodiment of the present invention can effectively remove suspended solids and impurities from high-concentration lithium iron phosphate wastewater through multi-stage treatment. It can also concentrate the wastewater through multi-stage treatment, effectively increasing the proportion of lithium ions in the concentrated water and improving the water resource reuse rate. Furthermore, the remaining concentrated water in the crystallization sedimentation tank 7 can re-enter the primary slag removal module 2, achieving zero-discharge treatment of wastewater and meeting the requirements of relevant environmental protection regulations and standards.

[0032] like Figure 1 As shown, a wastewater treatment system 100 according to an embodiment of the present invention includes: a wastewater collection tank 1, a primary slag removal module 2, a COD treatment module 3, a secondary slag removal module 4, a multi-stage wastewater concentration module 5, a recycled water tank 6, and a crystallization sedimentation tank 7.

[0033] The inlet of the primary slag removal module 2 is connected to the wastewater collection tank 1; the inlet of the COD treatment module 3 is connected to the outlet of the primary slag removal module 2; the inlet of the secondary slag removal module 4 is connected to the outlet of the COD treatment module 3; the inlet of the multi-stage wastewater concentration module 5 is connected to the outlet of the secondary slag removal module 4; the recycled water tank 6 and the crystallization sedimentation tank 7 are respectively connected to the multi-stage wastewater concentration module 5, and the crystallization sedimentation tank 7 is connected to a circulating return water path 71 connected to the primary slag removal module 2.

[0034] Specifically, wastewater collection tank 1 is used to contain and collect wastewater. Primary sludge removal module 2 is used to treat some suspended solids and residues in the wastewater. The inlet end of primary sludge removal module 2 is connected to wastewater collection tank 1, so that wastewater in wastewater collection tank 1 can enter primary sludge removal module 2 from the inlet end of primary sludge removal module 2 for preliminary sludge removal to remove some suspended solids and residues in the wastewater. COD treatment module 3 is used to treat COD in wastewater. The inlet end of COD treatment module 3 is connected to the outlet end of primary sludge removal module 2, so that wastewater treated by primary sludge removal module 2 can enter COD treatment module 3 from the outlet end of primary sludge removal module 2 through the inlet end of COD treatment module 3 for COD treatment in wastewater.

[0035] Meanwhile, the secondary sludge removal module 4 is used to further remove some suspended solids and residues from the wastewater. The inlet end of the secondary sludge removal module 4 is connected to the outlet end of the COD treatment module 3, so that the wastewater treated by the COD treatment module 3 can enter the secondary sludge removal module 4 from the outlet end of the COD treatment module 3 through the inlet end of the secondary sludge removal module 4. In the secondary sludge removal module 4, sludge sedimentation and sludge removal are carried out again, which can further remove some suspended solids and impurities from the wastewater. The multi-stage wastewater concentration module 5 is used to concentrate the wastewater in multiple stages. The inlet end of the multi-stage wastewater concentration module 5 is connected to the outlet end of the secondary sludge removal module 4, so that the wastewater treated by the secondary sludge removal module 4 can enter the multi-stage wastewater concentration module 5 from the outlet end of the secondary sludge removal module 4 through the inlet end of the multi-stage wastewater concentration module 5. In the multi-stage wastewater concentration module 5, multiple stages of concentration are carried out. The multi-stage concentration can be at least one stage of concentration, that is, one-stage concentration, two-stage concentration, or three-stage concentration, which can be flexibly selected according to specific conditions.

[0036] Furthermore, the recycled water tank 6 is used to collect treated wastewater that meets production water standards, and the crystallization sedimentation tank 7 is used to recover recyclable resources from the wastewater. The recycled water tank 6 and the crystallization sedimentation tank 7 are connected to the multi-stage wastewater concentration module 5, so that the wastewater that meets production water standards after multi-stage concentration can enter the recycled water tank 6, and the concentrated water after multi-stage concentration can enter the crystallization sedimentation tank 7, where recyclable resources are recovered. The crystallization sedimentation tank 7 is connected to a circulating return water path 71 that connects to the primary slag removal module 2. That is, the circulating return water path 71 can connect the crystallization sedimentation tank 7 and the primary slag removal module 2, so that the remaining concentrated water in the crystallization sedimentation tank 7 can enter the primary slag removal module 2 along the circulating return water path 71 and undergo a new round of treatment together with the new wastewater.

[0037] It should be noted that the wastewater collection tank 1 can be used to collect high-concentration lithium iron phosphate wastewater, that is, the wastewater treatment system 100 of this application can be used to treat high-concentration lithium iron phosphate wastewater and recover lithium ions from the wastewater.

[0038] Therefore, the primary slag removal module 2 and the secondary slag removal module 4 can effectively remove suspended solids and impurities from the high-concentration wastewater of lithium iron phosphate. The COD treatment module 3 can treat the COD in the wastewater. The multi-stage wastewater concentration module 5 can concentrate the wastewater in multiple stages, increasing the proportion of lithium ions in the concentrated water and improving the water resource reuse rate. The recycled water tank 6 collects the production water that meets the production water standard. The crystallization sedimentation tank 7 recovers the recyclable resources in the concentrated water. The remaining concentrated water in the crystallization sedimentation tank 7 is transported to the primary slag removal module 2 through the circulating return water path 71 for a new round of treatment with the new wastewater.

[0039] According to the wastewater treatment system 100 of this utility model embodiment, by performing multi-stage treatment on high-concentration lithium iron phosphate wastewater, suspended solids and impurities in the wastewater can be effectively removed, and the wastewater can be concentrated in multiple stages to effectively increase the proportion of lithium ions in the concentrated water and improve the water resource reuse rate. In addition, the remaining concentrated water in the crystallization sedimentation tank 7 can re-enter the primary slag removal module 2, thereby achieving zero-discharge treatment of wastewater and meeting the requirements of relevant environmental protection regulations and standards.

[0040] In some embodiments, the primary slag removal module 2 includes a coagulation sedimentation tank 21 and a combined air flotation machine 22. The inlet end of the coagulation sedimentation tank 21 is connected to the wastewater collection tank 1, the outlet end of the coagulation sedimentation tank 21 is connected to the inlet end of the combined air flotation machine 22, the outlet end of the combined air flotation machine 22 is connected to the inlet end of the COD treatment module 3, and the outlet end of the circulating return water path 71 is connected to the coagulation sedimentation tank 21.

[0041] Specifically, the primary sludge removal module 2 can perform preliminary treatment of suspended solids and impurities in wastewater. The primary sludge removal module 2 includes a coagulation sedimentation tank 21 and a combined air flotation machine 22. The coagulation sedimentation tank 21 is used to settle suspended solids, phosphorus and some settleable substances contained in the wastewater. The combined air flotation machine 22 is used to remove residual suspended solids and other residues in the wastewater. The inlet end of the coagulation sedimentation tank 21 is connected to the wastewater collection tank 1, so that the wastewater collected in the wastewater collection tank 1 can be homogenized and homogenized in the wastewater collection tank 1 before entering the coagulation sedimentation tank 21 from the inlet end of the coagulation sedimentation tank 21. The outlet end of the coagulation sedimentation tank 21 is connected to the inlet end of the combined air flotation machine 22, so that the wastewater treated by the coagulation sedimentation tank 21 can enter the combined air flotation machine 22 from the outlet end of the coagulation sedimentation tank 21 through the inlet end of the combined air flotation machine 22 for further treatment.

[0042] Polyferric chloride can be added to the coagulation sedimentation tank 21 to precipitate phosphate, that is, to precipitate phosphorus in the wastewater. Suspended solids in the wastewater are removed by stirring and settling. In the combined air flotation machine 22, the suspended solids and residues in the wastewater can be exposed to the top of the combined air flotation machine 22 by internal aeration, and then the suspended solids and residues are scraped out by scrapers and other tools.

[0043] Simultaneously, connecting the outlet of the combined flotation unit 22 to the inlet of the COD treatment module 3 enables simultaneous connection between the primary slag removal module 2, the wastewater collection tank 1, and the COD treatment module 3. This allows the wastewater treated by the combined flotation unit 22 to enter the COD treatment module 3 from its outlet through the inlet. The COD in the wastewater is then treated within the COD treatment module 3. Connecting the outlet of the circulation return water path 71 to the coagulation sedimentation tank 21 connects the outlet of the circulation return water path 71 to the primary slag removal module 2. This allows the remaining high-concentration wastewater in the crystallization sedimentation tank 7 to enter the coagulation sedimentation tank 21 from its outlet. In the coagulation sedimentation tank 21, the wastewater mixes with and is diluted by the new wastewater entering from the wastewater collection tank 1 before entering the new circulation process.

[0044] It should be noted that the phosphorus content in the wastewater collected in wastewater collection tank 1 can reach over 1000 ppm. After treatment by coagulation sedimentation tank 21 and combined air flotation machine 22, the phosphorus content can be reduced to less than 100 ppm. Moreover, more than 99% of the impurities and sediments in the wastewater can be removed. Furthermore, the high-concentration wastewater treated by wastewater treatment system 100 can be diluted by at least 26.7 times after entering coagulation sedimentation tank 21, which greatly reduces the impact on new wastewater entering coagulation sedimentation tank 21 from wastewater collection tank 1. In addition, due to the intermittent nature of the wastewater source, the dilution ratio fully meets the requirements of secondary treatment.

[0045] In some embodiments, the COD treatment module 3 includes a catalytic structure 31 and a biochemical treatment structure 32. The inlet end of the catalytic structure 31 is connected to the outlet end of the primary slag removal module 2, the outlet end of the catalytic structure 31 is connected to the inlet end of the biochemical treatment structure 32, and the outlet end of the biochemical treatment structure 32 is connected to the secondary slag removal module 4.

[0046] Specifically, the COD treatment module 3 is used to treat COD in wastewater. The COD treatment module 3 includes a catalytic structure 31 and a biochemical treatment structure 32. The catalytic structure 31 is used for preliminary COD treatment, and the biochemical treatment structure 32 is used for advanced COD treatment. By connecting the inlet end of the catalytic structure 31 to the outlet end of the primary slag removal module 2, the inlet end of the catalytic structure 31 can be connected to the outlet end of the combined air flotation unit 22. This allows the wastewater treated by the primary slag removal module 2 to enter the catalytic structure 31 from the outlet end of the combined air flotation unit 22 through the inlet end of the catalytic structure 31. By connecting the outlet end of the catalytic structure 31 to the inlet end of the biochemical treatment structure 32, the wastewater treated by the catalytic structure 31 can enter the biochemical treatment structure 32 from the outlet end of the catalytic structure 31 through the inlet end of the biochemical treatment structure 32 for further treatment.

[0047] Among them, the catalytic structure 31 can treat COD in wastewater through oxidation, and in the biochemical treatment structure 32, anaerobic and aerobic bacteria can be cultivated to decompose ammonia nitrogen, total nitrogen and COD in wastewater, and degrade COD to an extremely low level.

[0048] Meanwhile, by connecting the outlet end of the biochemical treatment structure 32 to the secondary slag removal module 4, the outlet end of the COD treatment module 3 and the secondary slag removal module 4 can be connected, allowing the wastewater treated by the COD treatment module 3 to enter the secondary slag removal module 4 from the outlet end of the biochemical treatment structure 32 for further slag removal.

[0049] In some embodiments, the catalytic structure 31 includes an XE catalytic structure 311 and a secondary catalytic structure 312. The inlet end of the XE catalytic structure 311 is connected to the outlet end of the primary slag removal module 2, the outlet end of the XE catalytic structure 311 is connected to the inlet end of the secondary catalytic structure 312, and the outlet end of the secondary catalytic structure 312 is connected to the inlet end of the biochemical treatment structure 32.

[0050] Specifically, the catalytic structure 31 is used to oxidize COD. The catalytic structure 31 includes an XE catalytic structure 311 and a secondary catalytic structure 312. The XE catalytic structure 311 can oxidize COD in wastewater, and the secondary catalytic structure 312 can perform secondary oxidation of COD in wastewater, which can improve the ability and effect of COD oxidation treatment. By connecting the inlet end of the XE catalytic structure 311 to the outlet end of the primary slag removal module 2, the COD treatment module 3 and the primary slag removal module 2 can be connected. This allows the wastewater treated by the primary slag removal module 2 to enter the XE catalytic structure 311 from the outlet end of the primary slag removal module 2 through the inlet end of the XE catalytic structure 311. By connecting the outlet end of the XE catalytic structure 311 to the inlet end of the secondary catalytic structure 312, the wastewater treated by the XE catalytic structure 311 can enter the secondary catalytic structure 312 from the outlet end of the XE catalytic structure 311 through the inlet end of the secondary catalytic structure 312 for further treatment.

[0051] Among them, COD can be oxidized by passing electricity through the positive and negative electrodes of the XE catalytic structure 311 to generate free radical hydroxyl groups, and COD can be separated into carbon dioxide and water, etc. Ferrous iron and sulfuric acid can be added to the secondary catalytic structure 312 to perform secondary oxidation of COD, so as to improve the ability and effect of oxidizing COD.

[0052] Meanwhile, by connecting the outlet end of the secondary catalytic structure 312 with the inlet end of the biochemical treatment structure 32, the catalytic structure 31 and the biochemical treatment structure 32 can be connected, so that the wastewater treated by the secondary catalytic structure 312 can enter the biochemical treatment structure 32 from the outlet end of the secondary catalytic structure 312 through the inlet end of the biochemical treatment structure 32 for further treatment.

[0053] It should also be noted that the COD content in the wastewater collected in wastewater collection tank 1 can reach over 1000 ppm. After passing through the XE catalytic structure 311 and the secondary catalytic structure 312, 50% of the recalcitrant COD in the wastewater can be removed, and over 30% of the readily degradable COD can be removed. This ensures that the COD content in the wastewater can be below 200 ppm before entering the biochemical treatment structure 32. After entering the biochemical treatment structure 32, over 90% of the COD is consumed by the growth of biological bacteria. In other words, the COD content in the wastewater after treatment by the COD treatment module 3 can be stably controlled below 20 ppm.

[0054] In some embodiments, an intermediate reflux water path 321 is also connected between the outlet end of the biochemical treatment structure 32 and the inlet end of the XE catalytic structure 311.

[0055] Specifically, the outlet end of the biochemical treatment structure 32 is connected to the inlet end of the XE catalytic structure 311 through an intermediate reflux water passage 321. This allows some of the wastewater treated by the biochemical treatment structure 32 to enter the XE catalytic structure 311 from the outlet end of the biochemical treatment structure 32 through the inlet end of the XE catalytic structure 311, and then flow back into the XE catalytic structure 311 to mix with the wastewater inside the XE catalytic structure 311. This reduces the load on the front-end treatment and allows the COD that cannot be decomposed by biological means to be oxidized again through free radical hydroxyl groups, thereby improving the COD treatment effect.

[0056] It should be noted that some of the wastewater treated by the biochemical treatment structure 32 can be recycled back to the XE catalytic structure 311 to dilute the overall COD concentration in the wastewater, further improving the COD treatment effect. Ultimately, the COD content in the wastewater treated by the COD treatment module 3 can be stably controlled below 10 ppm, reaching an extremely low level.

[0057] In some embodiments, the secondary slag removal module 4 includes at least one sedimentation structure 41 and at least one filtration module 42, wherein the at least one sedimentation structure 41 and at least one filtration module 42 are sequentially connected between the COD treatment module 3 and the multi-stage wastewater concentration module 5.

[0058] Specifically, the secondary sludge removal module 4 is used to further remove suspended solids and impurities from the wastewater. The secondary sludge removal module 4 includes at least one sedimentation structure 41 and at least one filter module 42. The sedimentation structure 41 can be used to settle sludge in the wastewater, and the filter module 42 is used to further treat suspended solids and impurities in the wastewater. The number of sedimentation structures 41 and filter modules 42 can be one, two, three or more. Sludge, suspended solids and impurities in the wastewater can be treated by at least one sedimentation structure 41 and at least one filter module 42, which can improve the treatment effect of sludge, suspended solids and impurities in the wastewater. At least one sedimentation structure 41 and at least one filter module 42 are sequentially connected between the COD treatment module 3 and the multi-stage wastewater concentration module 5. The COD treatment module 3, at least one sedimentation structure 41, at least one filter module 42 and multi-stage wastewater concentration module 5 are sequentially connected, so that the wastewater treated by the COD treatment module 3 can flow through at least one sedimentation structure 41, at least one filter module 42 and multi-stage wastewater concentration module 5 in sequence for treatment.

[0059] In some embodiments, the sedimentation structure 41 is one and is configured as an MBR membrane tank, and the filtration module 42 is two and is respectively configured as a multi-media filter 421 and a ceramic membrane device 422; wherein, the inlet end of the MBR membrane tank is connected to the outlet end of the COD treatment module 3, the outlet end of the MBR membrane tank is connected to the inlet end of the multi-media filter 421, the outlet end of the multi-media filter 421 is connected to the inlet end of the ceramic membrane device 422, and the outlet end of the ceramic membrane device 422 is connected to the multi-stage wastewater concentration module 5.

[0060] Specifically, the secondary sludge removal module 4 includes a sedimentation structure 41, which is constructed as an MBR membrane tank. The MBR membrane tank can be used for sludge sedimentation and effluent clarification. The sludge scraping ability of the MBR membrane can improve the biological treatment capacity. Furthermore, the MBR membrane filters wastewater and intercepts sludge, allowing the clarified wastewater to enter subsequent treatment steps. At the same time, the secondary sludge removal module 4 also includes two filtration modules 42, which are respectively constructed as a multi-media filter 421 and a ceramic membrane device 422. The multi-media filter 421 is used to treat some suspended solids and impurities in the wastewater, and the ceramic membrane device 422 is used to further treat the tiny suspended solids and impurities in the wastewater.

[0061] The inlet of the MBR membrane tank is connected to the outlet of the COD treatment module 3, allowing the wastewater treated by the COD treatment module 3 to enter the MBR membrane tank from the outlet of the COD treatment module 3 through the inlet of the MBR membrane tank. The outlet of the MBR membrane tank is connected to the inlet of the multi-media filter 421, allowing the wastewater treated by the MBR membrane tank to enter the multi-media filter 421 from the outlet of the MBR membrane tank through the inlet of the multi-media filter 421. The outlet of the multi-media filter 421 is connected to the inlet of the ceramic membrane device 422, allowing the wastewater treated by the multi-media filter 421 to enter the ceramic membrane device 422 from the outlet of the multi-media filter 421 through the inlet of the ceramic membrane device 422. Thus, the wastewater can flow sequentially through the MBR membrane tank, the multi-media filter 421, and the ceramic membrane device 422 in the secondary sludge removal module 4 to remove sludge, suspended solids, and impurities from the wastewater.

[0062] Furthermore, by connecting the outlet end of the ceramic membrane device 422 to the multi-stage wastewater concentration module 5, the outlet end of the secondary slag removal module 4 can be connected to the multi-stage wastewater concentration module 5, allowing the wastewater treated by the secondary slag removal module 4 to enter the multi-stage wastewater concentration module 5 from the outlet end of the ceramic membrane device 422 and be concentrated within the multi-stage wastewater concentration module 5.

[0063] It should also be noted that the COD treatment module 3 can control the COD content in the wastewater to an extremely low level to ensure that there is no contamination of the MBR membrane. After the wastewater is treated by the COD treatment module 3, it flows through the MBR membrane tank, where the activated sludge and residual bacteria in the MBR membrane tank can remove a very small portion of the COD in the wastewater. Then, it is further treated by the multi-media filter 421 and the ceramic membrane device 422 to ensure that the water quality is clear and meets the requirements before entering the next treatment step.

[0064] In some embodiments, the multi-stage wastewater concentration module 5 includes multiple wastewater concentration structures connected in series; wherein, among the multiple wastewater concentration structures, the upstream wastewater concentration structure is connected to the outlet end of the secondary slag removal module 4, and the downstream wastewater concentration structure is connected to the recycled water tank 6 and the crystallization sedimentation tank 7 respectively.

[0065] Specifically, the multi-stage wastewater concentration module 5 is used to concentrate wastewater. The multi-stage wastewater concentration module 5 includes multiple wastewater concentration structures connected in series, so that the wastewater can pass through multiple wastewater concentration structures in sequence for multi-stage concentration, thereby increasing the proportion of lithium ions in the concentrated water. The upstream wastewater concentration structure is connected to the outlet end of the secondary slag removal module 4, so that the outlet end of the secondary slag removal module 4 is connected to the multi-stage wastewater concentration module 5. The wastewater treated by the secondary slag removal module 4 can enter the upstream wastewater concentration structure from the outlet end of the secondary slag removal module 4 and flow through the multiple wastewater concentration structures connected in series for multi-stage concentration.

[0066] By connecting the downstream wastewater concentration structure to both the recycled water tank 6 and the crystallization sedimentation tank 7, the multi-stage wastewater concentration module 5 can be simultaneously connected to both the recycled water tank 6 and the crystallization sedimentation tank 7. This allows the wastewater that meets production water standards after treatment by the multi-stage wastewater concentration module 5 to enter the recycled water tank 6 for use. The concentrated water after treatment by the multi-stage wastewater concentration module 5 can then enter the crystallization sedimentation tank 7, where recyclable resources are recovered.

[0067] Furthermore, by connecting the crystallization sedimentation tank 7 to the primary slag removal module 2 via the circulating return water path 71, zero-discharge recycling of wastewater can be achieved.

[0068] In some embodiments, there are four wastewater concentration structures, namely a primary concentration structure 51, a secondary concentration structure 52, a tertiary concentration structure 53, and a high-pressure concentration structure 54. The primary concentration structure 51, the secondary concentration structure 52, the tertiary concentration structure 53, and the high-pressure concentration structure 54 are connected in series, and the primary concentration structure 51 is connected to the recycled water tank 6 through a primary product water flow path 511.

[0069] Specifically, the multi-stage wastewater concentration module 5 includes four wastewater concentration structures: a primary concentration structure 51, a secondary concentration structure 52, a tertiary concentration structure 53, and a high-pressure concentration structure 54. The primary concentration structure 51 performs initial concentration and initial desalination of the wastewater. The secondary concentration structure 52, tertiary concentration structure 53, and high-pressure concentration structure 54 can sequentially perform multi-stage concentration of the wastewater. Furthermore, the primary concentration structure 51, secondary concentration structure 52, tertiary concentration structure 53, and high-pressure concentration structure 54 are connected in series, ensuring that the wastewater passes through the secondary sludge removal module 4. The treated wastewater first enters the primary concentration structure 51. After initial concentration in the primary concentration module, it sequentially enters the secondary concentration structure 52, the tertiary concentration structure 53, and the high-pressure concentration structure 54 for multi-stage concentration to effectively increase the proportion of lithium ions in the concentrated water. The high-pressure concentration structure 54 is connected to the recycled water tank 6 and the crystallization sedimentation tank 7, respectively, so that the concentrated water after multi-stage concentration can enter the crystallization sedimentation tank 7 for lithium ion recovery. The product water that meets the production water standards after multi-stage concentration can enter the recycled water tank 6 for later use.

[0070] Furthermore, the primary concentration structure 51 is connected to the recycled water tank 6 via the primary permeate flow path 511. This allows the permeate water, after being treated by the primary concentration structure 51 and meeting production water standards, to directly enter the recycled water tank 6 through the primary permeate flow path 511 without passing through the secondary concentration structure 52, the tertiary concentration structure 53, and the high-pressure concentration structure 54. This eliminates the need for subsequent concentration steps, reducing energy consumption. The primary concentration structure 51, secondary concentration structure 52, and high-pressure concentration structure 54 can all be RO (Reverse Osmosis) devices, while the tertiary concentration structure 53 can be a STRO (Spacer Tube Reverse Osmosis) device.

[0071] It should also be noted that the wastewater treated by the secondary slag removal module 4 enters the primary concentration structure 51, where it can be concentrated 4 times, with a water production rate of 75% for reuse. The reuse conductivity can be controlled at 200 μS / cm, meeting the standards for production water. The concentrated water after primary concentration structure 51 enters the secondary concentration structure 52, where it can be concentrated 3.3 times, with a water production rate of 60%. The water then enters the tertiary concentration structure 53, where it can be concentrated 2 times, with a water production rate of 50%. Finally, the water enters the high-pressure concentration structure 54 for forced concentration, which can be concentrated 2 times, with a water production rate of 50%.

[0072] Through this process, the overall water production rate can reach 96.25%, which can be completely reused in production. 3.75% of the concentrated water can enter the crystallization sedimentation tank 7, where sodium carbonate is added to precipitate lithium carbonate salt crystals with a purity of over 90%. After secondary processing, it can be reused in production, generating significant profits and saving production costs. Furthermore, the concentrated wastewater after crystallization can enter the coagulation sedimentation tank 21 in the primary slag removal module 2 along the circulating return water path 71. In the coagulation sedimentation tank 21, it mixes with the new wastewater entering from the wastewater collection tank 1 to be diluted, at least 26.7 times. This has minimal impact on the new wastewater entering from the wastewater collection tank 1. Due to the intermittent nature of the wastewater source, the dilution ratio fully meets the requirements for secondary treatment. Moreover, the multi-stage wastewater concentration module 5 keeps the concentration ratio of the concentrated water consistently above 20 times, resulting in significant energy savings and reduced consumption.

[0073] In some embodiments, a first concentrate return flow path 531 is connected between the outlet end of the tertiary concentration structure 53 and the inlet end of the secondary concentration structure 52, and a second concentrate return flow path 541 is connected between the outlet end of the high-pressure concentration structure 54 and the inlet end of the secondary concentration structure 52.

[0074] Specifically, a first concentrate return flow path 531 connects the outlet of the tertiary concentration structure 53 to the inlet of the secondary concentration structure 52. This allows some of the concentrate from the tertiary concentration structure 53 to flow back to the secondary concentration structure 52 and mix with the wastewater treated by the primary concentration structure 51 for combined treatment. Furthermore, a second concentrate return flow path 541 connects the outlet of the high-pressure concentration structure 54 to the inlet of the secondary concentration structure 52. This allows some of the concentrate from the high-pressure concentration structure 54 to flow back to the secondary concentration structure 52 and mix with the wastewater treated by the primary concentration structure 51 for combined treatment. This effectively improves the concentration of wastewater and increases the proportion of lithium ions in the concentrate.

[0075] Furthermore, it should be noted that the treatment process can completely filter and recover lithium resources from wastewater, achieving a lithium ion recovery concentration of up to 90%, which greatly improves the efficiency of lithium resource reuse and generates significant profits for enterprises.

[0076] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "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.

[0077] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A wastewater treatment system, characterized in that, include: Wastewater collection pond; A primary slag removal module, the inlet of which is connected to a wastewater collection tank; COD treatment module, wherein the inlet end of the COD treatment module is connected to the outlet end of the primary slag removal module; A secondary slag removal module, wherein the inlet end of the secondary slag removal module is connected to the outlet end of the COD treatment module; A multi-stage wastewater concentration module, wherein the inlet end of the multi-stage wastewater concentration module is connected to the outlet end of the secondary sludge removal module; The system includes a recycled water tank and a crystallization sedimentation tank, both of which are connected to the multi-stage wastewater concentration module. The crystallization sedimentation tank is connected to a circulating return water path that is connected to the primary slag removal module.

2. The wastewater treatment system according to claim 1, characterized in that, The primary slag removal module includes a coagulation sedimentation tank and a combined air flotation unit. The inlet end of the coagulation sedimentation tank is connected to the wastewater collection tank, the outlet end of the coagulation sedimentation tank is connected to the inlet end of the combined air flotation unit, the outlet end of the combined air flotation unit is connected to the inlet end of the COD treatment module, and the outlet end of the circulating return water path is connected to the coagulation sedimentation tank.

3. The wastewater treatment system according to claim 1, characterized in that, The COD treatment module includes a catalytic structure and a biochemical treatment structure. The inlet end of the catalytic structure is connected to the outlet end of the primary slag removal module, the outlet end of the catalytic structure is connected to the inlet end of the biochemical treatment structure, and the outlet end of the biochemical treatment structure is connected to the secondary slag removal module.

4. The wastewater treatment system according to claim 3, characterized in that, The catalytic structure includes an XE catalytic structure and a secondary catalytic structure. The inlet end of the XE catalytic structure is connected to the outlet end of the primary slag removal module, the outlet end of the XE catalytic structure is connected to the inlet end of the secondary catalytic structure, and the outlet end of the secondary catalytic structure is connected to the inlet end of the biochemical treatment structure.

5. The wastewater treatment system according to claim 4, characterized in that, An intermediate reflux water path is also connected between the outlet end of the biochemical treatment structure and the inlet end of the XE catalytic structure.

6. The wastewater treatment system according to claim 1, characterized in that, The secondary slag removal module includes at least one sedimentation structure and at least one filtration module, wherein the at least one sedimentation structure and the at least one filtration module are sequentially connected between the COD treatment module and the multi-stage wastewater concentration module.

7. The wastewater treatment system according to claim 6, characterized in that, The sedimentation structure is a single structure configured as an MBR membrane tank, and the filtration modules are two structures configured as a multi-media filter and a ceramic membrane device, respectively. The inlet of the MBR membrane tank is connected to the outlet of the COD treatment module, the outlet of the MBR membrane tank is connected to the inlet of the multi-media filter, the outlet of the multi-media filter is connected to the inlet of the ceramic membrane device, and the outlet of the ceramic membrane device is connected to the multi-stage wastewater concentration module.

8. The wastewater treatment system according to claim 1, characterized in that, The multi-stage wastewater concentration module includes multiple wastewater concentration structures, which are connected in series. Among the multiple wastewater concentration structures, the upstream wastewater concentration structure is connected to the outlet end of the secondary slag removal module, and the downstream wastewater concentration structure is connected to the recycled water tank and the crystallization sedimentation tank respectively.

9. The wastewater treatment system according to claim 8, characterized in that, The wastewater concentration structures are four in total, namely a primary concentration structure, a secondary concentration structure, a tertiary concentration structure, and a high-pressure concentration structure. The primary concentration structure, the secondary concentration structure, the tertiary concentration structure, and the high-pressure concentration structure are connected in series, and the primary concentration structure is connected to the recycled water tank through a primary product water flow path.

10. The wastewater treatment system according to claim 9, characterized in that, A first concentrate return flow path is connected between the outlet end of the three-stage concentration structure and the inlet end of the two-stage concentration structure, and a second concentrate return flow path is connected between the outlet end of the high-pressure concentration structure and the inlet end of the two-stage concentration structure.

Images