Desalination and reuse of concentrated water, domestic sewage and economic system and method

Abstract

The application discloses a desalination concentrated and dilute water, domestic sewage economic reuse system and method, including desalination concentrated and dilute water treatment unit, domestic sewage treatment unit, reuse distribution unit and water distribution center;Desalination concentrated and dilute water treatment unit's entrance is connected with mine water buffer pond, and the outlet of desalination concentrated and dilute water treatment unit is connected with reuse distribution unit;The inlet of domestic sewage treatment unit inputs domestic sewage, and the outlet is connected with reuse distribution unit;The output end of reuse distribution unit is connected with the unit of water discharge / use;Water distribution center is used for monitoring dilute water recovery rate, concentrated and dilute water, mixed water and the water quality index of domestic sewage after treatment.The invention realizes the low load operation of mine water desalination system by limiting the water quality requirement of water discharge mine water, and realizes 100% self-circulation reuse of concentrated water by the reuse path expansion of concentrated water, which avoids the high construction investment, high operation cost and low economy of traditional high-salt concentrated water evaporation crystallization zero discharge system.

Description

Technical Field

[0001] This application belongs to the field of water treatment technology and relates to an economical system and method for the reuse of desalinated concentrated water and domestic sewage. Background Technology

[0002] The main water sources requiring treatment in coal mines are mine runoff and domestic sewage. After years of intensive mining, most coal mines have shifted to mining lower coal seams. With increasing mining depth, the mineralization of mine water has significantly increased. Currently, if there is surplus mine water after full utilization and it needs to be discharged, the treated water discharged must comply with relevant laws, regulations, and policies. Furthermore, its water quality parameters must meet or exceed the corresponding surface water environmental quality values ​​stipulated in the environmental functional zoning of the receiving water body. Total salinity must not exceed 1000 mg / L, and it must not affect the water function requirements of upstream and downstream river sections. Currently, more than half of the mine water has a total dissolved solids (TDS) exceeding 1000 mg / L, rendering conventional mine water treatment processes inadequate and requiring substantial investment in technological upgrades. Generally, mine water with a TDS of 1000–2000 mg / L is considered brackish water, and this type of mine water currently accounts for more than 70% of high-mineralized water. The conventional high-mineralization treatment process is "deep treatment + desalination and concentration + concentrated water evaporation and crystallization". The construction and operating costs of evaporation and crystallization equipment are extremely high. Furthermore, to reduce the scale of the evaporation and crystallization equipment, multi-stage concentration systems are usually required, resulting in high equipment footprint and maintenance costs, making it uneconomical. At the same time, due to the limited space in most old coal mines, the extremely high investment cost, lengthy systems, and difficult maintenance of zero-discharge concentrated water evaporation and crystallization systems make it difficult to choose a treatment method for mine water with slightly elevated TDS levels. Coal mine domestic wastewater typically uses a "physical pretreatment + biochemical treatment" process, with an effluent reuse rate of 50-60% and a very low reclaimed water recycling rate, resulting in water waste and increased water intake costs. Many mines in Gansu Province, located in collapsible loess areas surrounded by basic farmland, lack the conditions to build evaporation ponds and cannot discharge concentrated brine. Summary of the Invention

[0003] The purpose of this application is to solve the problems in the prior art and provide an economical system and method for the reuse of desalinated concentrated water and domestic sewage, so as to realize the internal digestion of desalinated concentrated water and the complete reuse of domestic sewage without the need to build a new evaporation and crystallization system, while expanding the internal use of desalinated fresh water and improving water resource utilization.

[0004] To achieve the above objectives, this application adopts the following technical solution:

[0005] In a first aspect, this application provides an economical system for the reuse of desalinated concentrated water and domestic sewage, comprising:

[0006] A desalination concentrated and desalinated water treatment unit, wherein the inlet of the desalination concentrated and desalinated water treatment unit is connected to the mine water buffer tank, and the outlet of the desalination concentrated and desalinated water treatment unit is connected to the reuse distribution unit.

[0007] A domestic sewage treatment unit, wherein domestic sewage is input at the inlet and connected to a reuse and distribution unit at the outlet;

[0008] A reuse and distribution unit, the output of which is connected to an external discharge / water use unit;

[0009] The water distribution center has its control terminal connected to the control terminal of the reuse distribution unit and its data acquisition terminal connected to the discharge / use unit. The water distribution center is used to monitor the water quality indicators of freshwater recovery rate, concentrated and fresh water, mixed water and reclaimed water after domestic sewage treatment, and to monitor and statistically analyze water consumption, water demand and water inflow in real time.

[0010] Firstly, this application provides an economical method for reusing desalinated concentrated water and domestic sewage, comprising the following steps:

[0011] Mining water with slightly excessive TDS enters a mine water buffer tank for homogenization and storage. The tank has two outlets: one goes to a mixing and compliant discharge device for mixing, and the other goes to a softening and purification system for hardening and turbidity removal. The effluent from the softening and purification system enters a membrane desalination system for desalination, and the effluent is divided into fresh water and concentrated water. The fresh water is reused to domestic water supply devices and underground system water supply devices through a fresh water reuse and distribution device. Excess fresh water is mixed with the raw mining water to be mixed. The quality of the discharged water should be TDS≤1000mg / L.

[0012] The concentrated water is recycled to the mud grouting water replenishment device, the coal washing production replenishment water device, and the coal storage system spray device through the concentrated water recycling and distribution device; the coal washing production replenishment water adopts domestic sewage recycling water, slurry pump shaft seal cooling drainage and some concentrated water mixed water, which can reduce the salt content of concentrated brine as coal washing production replenishment water.

[0013] Domestic sewage from the mine sequentially enters the physical treatment system and the biochemical treatment system. The effluent then enters the greywater reuse distribution device, which is connected to the dust suppression sprinkler system of the production system, the domestic miscellaneous water system, and the concentrated water reuse distribution device, achieving 100% reuse of greywater. Domestic sewage from the mining area is treated at the sewage treatment plant and reused for surface domestic miscellaneous uses, as well as for production water replenishment in the coal washing plant and dust suppression sprinkler system of the production system.

[0014] The water distribution center is connected to the blending and discharge device, freshwater reuse distribution device, concentrated water reuse distribution device, and reclaimed water reuse distribution device. It is used to monitor the freshwater recovery rate, concentrated and freshwater, blended water, and reclaimed water after domestic sewage treatment in the mine water system. It also provides real-time monitoring and statistics on water consumption, demand, and inflow. The distribution device is adjusted in real-time according to the needs of each water point, ensuring that all desalination concentrate is reused through the concentrated water reuse distribution device. When the water supply is insufficient, it is supplemented through the reclaimed water reuse distribution device. The water distribution center also monitors the mine water discharge device to ensure it meets standards. When the salinity exceeds the standard, increase the amount of mine water entering the softening and purification system from the mine water buffer tank or increase the recovery rate of the membrane desalination system, and reduce the amount of mine water entering the mine water buffer tank to the blending and discharge device. Ensure that the water quality of the mine water blending and discharge device meets the discharge requirements and is set as the first priority, thereby reducing the operating capacity of the mine water treatment system and lowering the operating cost. By increasing the amount of mine water blending and discharge, ensuring the full reuse of concentrated water, and reducing the output of the mine water treatment system, the operating cost can be reduced. At the same time, the full reuse of concentrated water and reclaimed water is controlled.

[0015] Compared with the prior art, this application has the following beneficial effects:

[0016] This invention achieves low-level operation of the mine water desalination system by strictly controlling the quality requirements of discharged mine water. Simultaneously, by expanding the reuse pathways for concentrated water, it achieves 100% self-circulation and reuse of concentrated water, avoiding the high construction investment, high operating costs, and low economic efficiency of traditional high-salinity concentrated water evaporation and crystallization zero-discharge systems. Through the rational allocation and use of concentrated and desalinated mine water, and by expanding the reuse pathways for treated domestic sewage, it achieves adaptability, full-process, and comprehensive reuse of mine water resources, improving the environmental protection level of mine water and reducing water waste. This invention is particularly suitable for coal mines with slightly excessive TDS levels in their mine water, solving problems such as limited construction space, extremely high investment costs for concentrated water evaporation and crystallization zero-discharge systems, and the complexity and difficulty of system operation and maintenance. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the system of the present invention.

[0019] Among them: 1 is the mine water buffer tank, 2-1 is the softening and purification system, 2-2 is the membrane desalination system, 3 is the fresh water reuse distribution device, 4 is the concentrated water reuse distribution device, 5 is the mixed and qualified discharge device, 6-1 is the domestic sewage physical treatment system, 6-2 is the domestic sewage biochemical treatment system, 7 is the reclaimed water reuse distribution device, and 8 is the water distribution center. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0022] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0023] In the description of the embodiments of this application, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing this application 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 on this application. In addition, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0024] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0025] In the description of the embodiments of this application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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 application according to the specific circumstances.

[0026] The present application will now be described in further detail with reference to the accompanying drawings:

[0027] See Figure 1 This application discloses an economical reuse system for desalinated concentrated and fresh water and domestic sewage, including a mine water buffer tank 1, a softening and purification system 2-1, a membrane desalination system 2-2, a fresh water reuse distribution device 3, a concentrated water reuse distribution device 4, a blending and compliant discharge device 5, a domestic sewage physical treatment system 6-1, a domestic sewage biochemical treatment system 6-2, a greywater reuse distribution device 7, a water distribution center 8, a mine water compliant discharge device 8-1, a domestic water device 8-2, an underground system water device 8-3, a yellow mud grouting water replenishment device 8-4, a coal washing production replenishment water device 8-5, a coal storage system spray device 8-6, a production system dust suppression watering device 8-7, and a domestic miscellaneous water device 8-8. This application targets mine water with slightly excessive TDS (total dissolved solids) and a TDS range of 1000–2000 mg / L.

[0028] In this application, the mine water enters the mine water buffer tank 1. The effluent from the mine water buffer tank 1 is divided into two streams: one stream enters the softening and purification system 2-1, and the other stream enters the blending and standard-compliant discharge device 5. The effluent from the softening and purification system 2-1 enters the membrane desalination system 2-2. The freshwater outlet of the membrane desalination system 2-2 enters the freshwater reuse distribution device 3, and the concentrated water outlet is divided into two streams: one stream enters the concentrated water reuse distribution device 4, and the other stream enters the blending and standard-compliant discharge device 5. The softening and purification system 2-1 includes softening, clarification, and filtration devices, and the membrane desalination system 2-2 includes processes such as reverse osmosis, nanofiltration, and electrodialysis. The blending and standard-compliant discharge device 5 is connected to the mine water standard-compliant discharge device 8-1. The freshwater reuse distribution device 3 is connected to the domestic water device 8-2 and the underground system water device 8-3. The concentrated water reuse distribution device 4 is connected to the yellow mud grouting water replenishment device 8-4, the coal washing production replenishment water device 8-5, and the coal storage system spray device 8-6.

[0029] Domestic sewage enters the physical treatment system 6-1, the effluent enters the biological treatment system 6-2, and the effluent enters the reclaimed water distribution device 7. The physical treatment system 6-1 includes screens and filters, while the biological treatment system 6-2 includes processes such as contact oxidation and biofilm. The reclaimed water distribution device 7 is connected to the dust suppression sprinkler system 8-7 of the production system, the domestic miscellaneous water system 8-8, and the concentrated water reclaimed water distribution device 4, achieving 100% reuse of reclaimed water.

[0030] The water distribution center 8 is connected to the blending and discharge device 5, the freshwater reuse distribution device 3, the concentrated water reuse distribution device 4, and the reclaimed water reuse distribution device 7. The water distribution center 8 has the function of monitoring the freshwater recovery rate, concentrated and freshwater, blended water, and reclaimed water after domestic sewage treatment in the mine water system. The indicators are salinity, total nitrogen, COD, and other parameters. At the same time, the water distribution center 8 monitors and statistically analyzes the water consumption, water demand, and water inflow in real time.

[0031] The water distribution center 8 adjusts the distribution device in real time according to the needs of each water point to ensure that all desalination concentrate is reused through the concentrate reuse distribution device 4. When the water volume is insufficient, the water volume is supplemented through the reclaimed water reuse distribution device 7. When the water distribution center 8 detects that the salt content of the mine water compliant discharge device 8-1 exceeds the standard, it increases the amount of mine water entering the softening and purification system 2-1 from the mine water buffer tank 1 or increases the recovery rate of the membrane desalination system 2-2 and decreases the amount of mine water entering the mine water buffer tank 1 to the mixed compliant discharge device 5. It ensures that the water quality of the mine water mixed compliant discharge device 8-1 meets the discharge requirements and is set as the first priority, thereby reducing the operating capacity of the mine water treatment system and reducing operating costs.

[0032] This application calculates water quality indicators such as conductivity of the discharged water formed by mixing mine water and fresh water to control and ensure that the quality of the mixed mine water discharge meets the standards. This achieves a dynamic limit balance between the mixed mine water and fresh water volumes. Furthermore, the recovery rate of the membrane desalination system in the mine water treatment system is controlled by limiting the fresh water volume, thereby reducing the workload of the mine water treatment system. Specifically, by increasing the amount of mixed mine water discharged, ensuring the full reuse of concentrated water, and reducing the output of the mine water treatment system, the operating cost is reduced. At the same time, by controlling the full reuse of concentrated water and reclaimed water, a short-process, economical reuse scheme for mine water and domestic sewage with slightly excessive salinity is achieved.

[0033] The specific working process of this invention is as follows:

[0034] The mine water with slightly excessive TDS enters the mine water buffer tank 1 for homogenization and storage. The tank has two outlets. One outlet goes directly into the mixing and discharge device 5 without any treatment, and the other outlet goes into the softening and purification system 2-1 to reduce hardness and remove turbidity. The water from the softening and purification system 2-1 continues to enter the membrane desalination system 2-2 for desalination. The water is then separated into fresh water and concentrated water. The freshwater quality should simultaneously meet the Class III standards of the "Emission Standard of Pollutants for Coal Industry" (GB20426-2006) and the "Environmental Quality Standard for Surface Water" (GB3838-2002). The freshwater can be reused in domestic water supply devices 8-2 (such as employee laundry and bathing, boiler room water supply in production and living areas, canteen water supply, etc.) and underground system water supply devices 8-3 (such as shaft seal water, underground sprinkler, dust prevention, fire fighting, etc., meeting the requirements of the "Design Code for Fire Fighting and Sprinkler System in Coal Mines" (GB50383-2006)). Excess freshwater is mixed with the raw mine water to be mixed, and the quality of the discharged water should meet the requirement of TDS≤1000mg / L.

[0035] The concentrated water can be reused through the concentrated water recycling and distribution device 4 to the yellow mud grouting water replenishment device 8-4, the coal washing production water replenishment device 8-5, and the coal storage system spraying device 8-6, etc. Currently, environmental impact assessments for mines require the concentrated brine to be digested through yellow mud grouting. Using concentrated brine for yellow mud grouting not only ensures underground safety but also protects the surface ecological environment. It is necessary to observe changes in the salinity of mine drainage, using the original mine drainage salinity as a reference, and adding concentrated brine appropriately without increasing the salinity. The current coal washing engineering design specification, "Coal Washing Water Standard" (GB50359-2005), does not specify requirements for the salinity of coal washing production replenishment water or for heavy media. Concentrated brine containing inorganic salts has no negative impact on the coal washing process or coal products. The coal washing production replenishment water uses recycled domestic sewage (fresh water), slurry pump shaft seal cooling drainage (demineralized water), and a mixture of some concentrated water, which can reduce the salinity of the concentrated brine used as coal washing production replenishment water.

[0036] Domestic sewage from the mine enters the physical treatment and biochemical treatment systems in sequence. The effluent then enters the reclaimed water distribution device 7, which is connected to the dust suppression and water spraying device 8-7 of the production system, the domestic miscellaneous water device 8-8, and the concentrated water reuse distribution device 4, respectively, to achieve 100% reuse of reclaimed water. The domestic sewage from the mine is treated by the domestic sewage treatment plant to meet the requirements of "Water Quality Standard for Urban Reclaimed Wastewater for Urban Miscellaneous Use" (GB / T18920-2002). If it is reused for underground production and water spraying, it is very likely to cause the total nitrogen, ammonia nitrogen and other indicators of the effluent from the mine water treatment plant to exceed the standards. Therefore, it is mainly reused for surface domestic miscellaneous use, as well as for production water replenishment in the coal washing plant and dust suppression and water spraying in the production system.

[0037] The water distribution center is connected and controlled by the blending and discharge device 5, the freshwater reuse distribution device 3, the concentrated water reuse distribution device 4, and the reclaimed water reuse distribution device 7. It has the function of monitoring the freshwater recovery rate of the mine water system, the quality indicators of concentrated and fresh water, blended water, and reclaimed water after domestic sewage treatment. The indicators include salinity, total nitrogen, COD, and other parameters. It performs real-time monitoring and statistics of water consumption, water demand, and water inflow. The distribution devices are adjusted in real-time according to the needs of each water point to ensure that all desalination concentrated water is reused through the concentrated water reuse distribution device 4. When the water volume is insufficient, the water is supplemented through the reclaimed water distribution device 7. When the water distribution center detects that the salt content of the mine water discharged through the standard-compliant discharge device 8-1 exceeds the standard, the amount of mine water entering the softening and purification system 2-1 from the mine water buffer tank 1 is increased, or the recovery rate of the membrane desalination system 2-2 is increased, and the amount of mine water entering the mixed standard-compliant discharge device 5 from the mine water buffer tank 1 is reduced. The water quality of the mixed standard-compliant discharge device 5 is ensured to meet the discharge requirements and is set as the first priority, thereby reducing the operating capacity of the mine water treatment system and lowering the operating cost. By controlling the mixed discharge of mine water to meet the standards, the workload of the mine water treatment system is reduced. That is, by increasing the amount of mixed discharge of mine water, ensuring the full reuse of concentrated water, and reducing the output of the mine water treatment system, the operating cost is reduced. At the same time, by controlling the full reuse of concentrated water and reclaimed water, a short-process, economical TDS-slightly exceeding mine water and domestic sewage economic reuse scheme is achieved.

[0038] The specific method for real-time adjustment and distribution of water demand at each water point is as follows:

[0039]

[0040] Q 矿井水 =Q 掺混 +Q 淡水 +Q 浓水

[0041] μ 矿井水 ×Q 矿井水 =μ 矿井水 ×Q 掺混 +μ 淡水 ×Q 淡水 +μ 浓水 ×Q 浓水

[0042] In the formula: Q 矿井水 The total amount of mine water with slightly excessive TDS requires treatment; μ 矿井水 The TDS level is slightly above the standard for salinity in mine water; Q 掺混 The volume of mine water with slightly excessive TDS levels directly mixed with and discharged to the standard-compliant external discharge device 5; Q 淡水 The volume of freshwater produced by the mine water treatment system with slightly elevated TDS levels; μ 淡水 The salinity of freshwater produced by a mine water treatment system with slightly excessive TDS; Q浓水 The concentrated water volume produced by the mine water treatment system with slightly excessive TDS; μ 浓水 The salinity of concentrated water produced by a mine water treatment system with slightly excessive TDS; μ 掺混排放 α represents the salt content of the mixed mine water discharged from the mine; α represents the recovery rate of the TDS-exceeding mine water treatment membrane desalination system 2-2.

[0043] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An economical system for reusing desalinated concentrated water and domestic sewage, comprising: The desalination concentrated and desalinated water treatment unit has its inlet connected to the mine water buffer tank (1) and its outlet connected to the reuse distribution unit. The desalination concentrated and desalinated water treatment unit includes a softening and purification system (2-1) and a membrane desalination system (2-2) connected in sequence. The inlet of the softening and purification system (2-1) is connected to the mine water buffer tank (1) and its outlet is connected to the reuse distribution unit. A domestic sewage treatment unit, wherein domestic sewage is input at the inlet and connected to a reuse and distribution unit at the outlet; The domestic sewage treatment unit includes a domestic sewage physical treatment system (6-1) and a domestic sewage biochemical treatment system (6-2) connected in sequence; the domestic sewage physical treatment system (6-1) is fed with domestic sewage at its inlet, and the domestic sewage biochemical treatment system (6-2) is connected to a reuse distribution unit at its outlet; The reuse distribution unit is connected to the discharge / water use unit. The reuse distribution unit includes a freshwater reuse distribution device (3), a concentrated water reuse distribution device (4), a mixed-standard discharge device (5), and a greywater reuse distribution device (7). The inlet of the mixed-standard discharge device (5) is connected to the concentrated water outlet of the mine water buffer tank (1) and the membrane desalination system (2-2), respectively. The inlet of the concentrated water reuse distribution device (4) is connected to the concentrated water outlet of the membrane desalination system (2-2). The inlet of the freshwater reuse distribution device (3) is connected to the freshwater outlet of the membrane desalination system (2-2). The outlets of the freshwater reuse distribution device (3), the concentrated water reuse distribution device (4), and the mixed-standard discharge device (5) are all connected to the inlet of the discharge / water use unit. The inlet of the greywater reuse distribution device (7) is connected to the domestic sewage biochemical treatment system (6-2), and the outlet is connected to the inlet of the discharge / water use unit. The external discharge / water use unit includes a mine water standard discharge device (8-1), a domestic water device (8-2), an underground system water device (8-3), a yellow mud grouting water replenishment device (8-4), a coal washing production water replenishment device (8-5), and a coal storage system spraying device (8-6); the inlet of the mine water standard discharge device (8-1) is connected to the outlet of the blending standard discharge device (5); the inlets of the domestic water device (8-2) and the underground system water device (8-3) are both connected to the outlet of the fresh water reuse distribution device (3). The inlets of the mud grouting water replenishment device (8-4), the coal washing production water replenishment device (8-5), and the coal storage system spray device (8-6) are all connected to the outlet of the concentrated water reuse distribution device (4); the data acquisition terminals of the mine water standard discharge device (8-1), the domestic water device (8-2), the underground system water device (8-3), the mud grouting water replenishment device (8-4), the coal washing production water replenishment device (8-5), and the coal storage system spray device (8-6) are all connected to the data acquisition terminal of the water distribution center (8); The external discharge / water use unit includes a dust suppression sprinkler system (8-7) and a domestic miscellaneous water use device (8-8); the inlets of the dust suppression sprinkler system (8-7) and the domestic miscellaneous water use device (8-8) are both connected to the outlet of the greywater reuse distribution device (7); the data acquisition terminals of the dust suppression sprinkler system (8-7) and the domestic miscellaneous water use device (8-8) are both connected to the data acquisition terminal of the water distribution center (8); Water distribution center (8), the control end of the water distribution center (8) is connected to the control end of the reuse distribution unit, and the data acquisition end is connected to the discharge / use unit; the water distribution center (8) is used to monitor the water quality indicators of fresh water recovery rate, concentrated fresh water, mixed water and reclaimed water after domestic sewage treatment, and to monitor and statistically analyze water consumption, water demand and water inflow in real time.

2. A method for economically reusing desalinated concentrated water and domestic sewage from the system described in claim 1, comprising the following steps: Mining water with slightly excessive TDS enters the mine water buffer tank (1) for homogenization and storage. The tank outlet is set with two paths: one path enters the mixing and discharge device (5) for mixing, and the other path enters the softening and purification system (2-1) to achieve hardness reduction and turbidity removal. The effluent from the softening and purification system (2-1) enters the membrane desalination system (2-2) for desalination. The effluent is divided into fresh water and concentrated water. The fresh water is reused to the domestic water device (8-2) and the underground system water device (8-3) through the fresh water reuse distribution device (3). Excess fresh water is mixed with the raw mine water to be mixed. The quality of the discharged water should be TDS≤1000mg / L. The concentrated water is recycled to the mud grouting water replenishment device (8-4), the coal washing production replenishment water device (8-5), and the coal storage system spray device (8-6) through the concentrated water recycling distribution device (4); the coal washing production replenishment water adopts the recycled water of domestic sewage, the cooling drainage of slurry pump shaft seal and some concentrated water, which can reduce the salt content of concentrated brine as coal washing production replenishment water; Domestic sewage from the mine enters the physical treatment system (6-1) and the biochemical treatment system (6-2) in sequence. The effluent enters the greywater reuse distribution device (7). The greywater reuse distribution device (7) is connected to the dust suppression sprinkler device (8-7), the domestic miscellaneous water device (8-8), and the concentrated water reuse distribution device (4) in the production system, so as to achieve 100% reuse of greywater. Domestic sewage from the mining area is treated by the domestic sewage treatment station and reused for domestic miscellaneous water use on the ground, as well as for production water replenishment in the coal washing plant and dust suppression sprinkler in the production system. The water distribution center (8) is connected to the mixing and discharge device (5), the fresh water reuse distribution device (3), the concentrated water reuse distribution device (4) and the greywater reuse distribution device (7) for monitoring the water quality indicators of fresh water recovery rate, concentrated and fresh water, mixed water and greywater after domestic sewage treatment in the mine water system, and for real-time monitoring and statistics of water consumption, water demand and water inflow. The distribution device is adjusted in real time according to the needs of each water point, so that the desalination concentrate is fully reused through the concentrate reuse distribution device (4). When the water volume is insufficient, the water volume is supplemented through the reclaimed water reuse distribution device (7). When the water distribution center detects that the salt content of the mine water standard discharge device (8-1) exceeds the standard, the amount of mine water entering the softening and purification system (2-1) from the mine water buffer pool (1) is increased or the recovery rate of the membrane desalination system (2-2) is increased, and the amount of mine water entering the mixing standard discharge device (5) from the mine water buffer pool (1) is reduced. The water quality of the mixing standard discharge device (5) meets the discharge requirements and is set as the first priority, thereby reducing the operating capacity of the mine water treatment system and reducing the operating cost. By increasing the amount of mine water mixing discharge, ensuring the full reuse of concentrate, and reducing the output of the mine water treatment system, the operating cost is reduced. At the same time, the full reuse of concentrate and reclaimed water is controlled.

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